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18 pages, 3536 KiB

Open AccessArticle

Controlling the Spatiotemporal Release of Nerve Growth Factor by Chitosan/Polycaprolactone Conduits for Use in Peripheral Nerve Regeneration

by Katarzyna Nawrotek, Monika Kubicka, Justyna Gatkowska, Marek Wieczorek, Sylwia Michlewska, Adrian Bekier, Radosław Wach and Karolina Rudnicka

Int. J. Mol. Sci. 2022, 23(5), 2852; https://doi.org/10.3390/ijms23052852 - 5 Mar 2022

Cited by 13 | Viewed by 3202

Abstract

Tubular polymeric structures have been recognized in the treatment of peripheral nerves as comparable to autologous grafting. The best therapeutic outcomes are obtained with conduits releasing therapeutic molecules. In this study, a new approach for the incorporation of biologically active agent-loaded microspheres into [...] Read more.

Tubular polymeric structures have been recognized in the treatment of peripheral nerves as comparable to autologous grafting. The best therapeutic outcomes are obtained with conduits releasing therapeutic molecules. In this study, a new approach for the incorporation of biologically active agent-loaded microspheres into the structure of chitosan/polycaprolactone conduits was developed. The support of a polycaprolactone helix formed by 3D melt extrusion was coated with dopamine in order to adsorb nerve growth factor-loaded microspheres. The complex analysis of the influence of process factors on the coverage efficiency of polycaprolactone helix by nerve grow factor-loaded microspheres was analyzed. Thus, the PCL helix characterized with the highest adsorption of microspheres was subjected to nerve growth factor release studies, and finally incorporated into chitosan hydrogel deposit through the process of electrophoretic deposition. It was demonstrated by chemical and physical tests that the chitosan/polycaprolactone conduit meets the requirements imposed on peripheral nerve implants, particularly mimicking mechanical properties of surrounding soft tissue. Moreover, the conduit may support regrowing nerves for a prolonged period, as its structure and integrity persist upon incubation in lysozyme-contained PBS solution up to 28 days at body temperature. In vitro cytocompatibility toward mHippoE-18 embryonic hippocampal cells of the chitosan/polycaprolactone conduit was proven. Most importantly, the developed conduits stimulate axonal growth and support monocyte activation, the latter is advantageous especially at early stages of nerve regeneration. It was demonstrated that, through the described approach for controlling spatiotemporal release of nerve growth factors, these biocompatible structures adjusted to the specific peripheral nerve injury case can be manufactured. Full article

(This article belongs to the Special Issue Optimization of Biomaterials for Reconstructive and Regenerative Medicine)

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23 pages, 5693 KiB

Open AccessArticle

Porcine Small Intestinal Submucosa (SIS) as a Suitable Scaffold for the Creation of a Tissue-Engineered Urinary Conduit: Decellularization, Biomechanical and Biocompatibility Characterization Using New Approaches

by Martina Casarin, Tiago Moderno Fortunato, Saima Imran, Martina Todesco, Deborah Sandrin, Giulia Borile, Ilaria Toniolo, Massimo Marchesan, Gino Gerosa, Andrea Bagno, Filippo Romanato, Emanuele Luigi Carniel, Alessandro Morlacco and Fabrizio Dal Moro

Int. J. Mol. Sci. 2022, 23(5), 2826; https://doi.org/10.3390/ijms23052826 - 4 Mar 2022

Cited by 34 | Viewed by 5705

Abstract

Bladder cancer (BC) is among the most common malignancies in the world and a relevant cause of cancer mortality. BC is one of the most frequent causes for bladder removal through radical cystectomy, the gold-standard treatment for localized muscle-invasive and some cases of [...] Read more.

Bladder cancer (BC) is among the most common malignancies in the world and a relevant cause of cancer mortality. BC is one of the most frequent causes for bladder removal through radical cystectomy, the gold-standard treatment for localized muscle-invasive and some cases of high-risk, non-muscle-invasive bladder cancer. In order to restore urinary functionality, an autologous intestinal segment has to be used to create a urinary diversion. However, several complications are associated with bowel-tract removal, affecting patients’ quality of life. The present study project aims to develop a bio-engineered material to simplify this surgical procedure, avoiding related surgical complications and improving patients’ quality of life. The main novelty of such a therapeutic approach is the decellularization of a porcine small intestinal submucosa (SIS) conduit to replace the autologous intestinal segment currently used as urinary diversion after radical cystectomy, while avoiding an immune rejection. Here, we performed a preliminary evaluation of this acellular product by developing a novel decellularization process based on an environmentally friendly, mild detergent, i.e., Tergitol, to replace the recently declared toxic Triton X-100. Treatment efficacy was evaluated through histology, DNA, hydroxyproline and elastin quantification, mechanical and insufflation tests, two-photon microscopy, FTIR analysis, and cytocompatibility tests. The optimized decellularization protocol is effective in removing cells, including DNA content, from the porcine SIS, while preserving the integrity of the extracellular matrix despite an increase in stiffness. An effective sterilization protocol was found, and cytocompatibility of treated SIS was demonstrated from day 1 to day 7, during which human fibroblasts were able to increase in number and strongly organize along tissue fibres. Taken together, this in vitro study suggests that SIS is a suitable candidate for use in urinary diversions in place of autologous intestinal segments, considering the optimal results of decellularization and cell proliferation. Further efforts should be undertaken in order to improve SIS conduit patency and impermeability to realize a future viable substitute. Full article

(This article belongs to the Special Issue Optimization of Biomaterials for Reconstructive and Regenerative Medicine)

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15 pages, 2750 KiB

Open AccessArticle

Octacalcium Phosphate for Bone Tissue Engineering: Synthesis, Modification, and In Vitro Biocompatibility Assessment

by Anastasia Yu. Teterina, Igor V. Smirnov, Irina S. Fadeeva, Roman S. Fadeev, Polina V. Smirnova, Vladislav V. Minaychev, Margarita I. Kobyakova, Aleksandr Yu. Fedotov, Sergey M. Barinov and Vladimir S. Komlev

Int. J. Mol. Sci. 2021, 22(23), 12747; https://doi.org/10.3390/ijms222312747 - 25 Nov 2021

Cited by 12 | Viewed by 2884

Abstract

Octacalcium phosphate (OCP, Ca₈H₂(PO₄)₆·5H₂O) is known to be a possible precursor of biological hydroxyapatite formation of organic bone tissue. OCP has higher biocompatibility and osseointegration rate compared to other calcium phosphates. In this [...] Read more.

Octacalcium phosphate (OCP, Ca₈H₂(PO₄)₆·5H₂O) is known to be a possible precursor of biological hydroxyapatite formation of organic bone tissue. OCP has higher biocompatibility and osseointegration rate compared to other calcium phosphates. In this work, the synthesis of low-temperature calcium phosphate compounds and substituted forms of those at physiological temperatures is shown. Strontium is used to improve bioactive properties of the material. Strontium was inserted into the OCP structure by ionic substitution in solutions. The processes of phase formation of low-temperature OCP with theoretical substitution of strontium for calcium up to 50 at.% in conditions close to physiological, i.e., temperature 35–37 °C and normal pressure, were described. The effect of strontium substitution range on changes in the crystal lattice of materials, the microstructural features, surface morphology and biological properties in vitro has been established. The results of the study indicate the effectiveness of using strontium in OCP for improving biocompatibility of OCP based composite materials intended for bone repair. Full article

(This article belongs to the Special Issue Optimization of Biomaterials for Reconstructive and Regenerative Medicine)

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12 pages, 2100 KiB

Open AccessArticle

Gelatin Methacryloyl–Riboflavin (GelMA–RF) Hydrogels for Bone Regeneration

by Ryoma Goto, Eisaku Nishida, Shuichiro Kobayashi, Makoto Aino, Tasuku Ohno, Yuki Iwamura, Takeshi Kikuchi, Jun-ichiro Hayashi, Genta Yamamoto, Masaki Asakura and Akio Mitani

Int. J. Mol. Sci. 2021, 22(4), 1635; https://doi.org/10.3390/ijms22041635 - 6 Feb 2021

Cited by 52 | Viewed by 5961

Abstract

Gelatin methacryloyl (GelMA) is a versatile biomaterial that has been used in various biomedical fields. UV light is commonly used to photocrosslink such materials; however, its use has raised several biosafety concerns. We investigated the mechanical and biological properties of a visible-wavelength (VW)-light-crosslinked [...] Read more.

Gelatin methacryloyl (GelMA) is a versatile biomaterial that has been used in various biomedical fields. UV light is commonly used to photocrosslink such materials; however, its use has raised several biosafety concerns. We investigated the mechanical and biological properties of a visible-wavelength (VW)-light-crosslinked gelatin-based hydrogel to evaluate its viability as a scaffold for bone regeneration in bone-destructive disease treatment. Irgacure2959 or riboflavin was added as a photoinitiator to create GelMA solutions. GelMA solutions were poured into a mold and exposed to either UV or VW light. KUSA-A1 cell-laden GelMA hydrogels were crosslinked and then cultured. Mechanical characterization revealed that the stiffness range of GelMA–RF hydrogel was suitable for osteoblast differentiation. KUSA-A1 cells encapsulated in GelMA hydrogels photopolymerized with VW light displayed significantly higher cell viability than cells encapsulated in hydrogels photopolymerized with UV light. We also show that the expression of osteogenesis-related genes at a late stage of osteoblast differentiation in osteoblasts encapsulated in GelMA–RF hydrogel was markedly increased under osteoblast differentiation-inducing conditions. The GelMA–RF hydrogel served as an excellent scaffold for the encapsulation of osteoblasts. GelMA–RF hydrogel-encapsulated osteoblasts have the potential not only to help regenerate bone mass but also to treat complex bone defects associated with bone-destructive diseases such as periodontitis. Full article

(This article belongs to the Special Issue Optimization of Biomaterials for Reconstructive and Regenerative Medicine)

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16 pages, 5528 KiB

Open AccessArticle

Toward Biofabrication of Resorbable Implants Consisting of a Calcium Phosphate Cement and Fibrin—A Characterization In Vitro and In Vivo

by Tilman Ahlfeld, Anja Lode, Richard Frank Richter, Winnie Pradel, Adrian Franke, Martina Rauner, Bernd Stadlinger, Günter Lauer, Michael Gelinsky and Paula Korn

Int. J. Mol. Sci. 2021, 22(3), 1218; https://doi.org/10.3390/ijms22031218 - 26 Jan 2021

Cited by 21 | Viewed by 4098

Abstract

Cleft alveolar bone defects can be treated potentially with tissue engineered bone grafts. Herein, we developed novel biphasic bone constructs consisting of two clinically certified materials, a calcium phosphate cement (CPC) and a fibrin gel that were biofabricated using 3D plotting. The fibrin [...] Read more.

Cleft alveolar bone defects can be treated potentially with tissue engineered bone grafts. Herein, we developed novel biphasic bone constructs consisting of two clinically certified materials, a calcium phosphate cement (CPC) and a fibrin gel that were biofabricated using 3D plotting. The fibrin gel was loaded with mesenchymal stromal cells (MSC) derived from bone marrow. Firstly, the degradation of fibrin as well as the behavior of cells in the biphasic system were evaluated in vitro. Fibrin degraded quickly in presence of MSC. Our results showed that the plotted CPC structure acted slightly stabilizing for the fibrin gel. However, with passing time and fibrin degradation, MSC migrated to the CPC surface. Thus, the fibrin gel could be identified as cell delivery system. A pilot study in vivo was conducted in artificial craniofacial defects in Lewis rats. Ongoing bone formation could be evidenced over 12 weeks but the biphasic constructs were not completely osseous integrated. Nevertheless, our results show that the combination of 3D plotted CPC constructs and fibrin as suitable cell delivery system enables the fabrication of novel regenerative implants for the treatment of alveolar bone defects. Full article

(This article belongs to the Special Issue Optimization of Biomaterials for Reconstructive and Regenerative Medicine)

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13 pages, 6528 KiB

Open AccessArticle

Toward Tailoring the Degradation Rate of Magnesium-Based Biomaterials for Various Medical Applications: Assessing Corrosion, Cytocompatibility and Immunological Effects

by Philip Hartjen, Nils Wegner, Parimah Ahmadi, Levi Matthies, Ola Nada, Sandra Fuest, Ming Yan, Christian Knipfer, Martin Gosau, Frank Walther and Ralf Smeets

Int. J. Mol. Sci. 2021, 22(2), 971; https://doi.org/10.3390/ijms22020971 - 19 Jan 2021

Cited by 8 | Viewed by 2979

Abstract

Magnesium (Mg)-based biomaterials hold considerable promise for applications in regenerative medicine. However, the degradation of Mg needs to be reduced to control toxicity caused by its rapid natural corrosion. In the process of developing new Mg alloys with various surface modifications, an efficient [...] Read more.

Magnesium (Mg)-based biomaterials hold considerable promise for applications in regenerative medicine. However, the degradation of Mg needs to be reduced to control toxicity caused by its rapid natural corrosion. In the process of developing new Mg alloys with various surface modifications, an efficient assessment of the relevant properties is essential. In the present study, a WE43 Mg alloy with a plasma electrolytic oxidation (PEO)-generated surface was investigated. Surface microstructure, hydrogen gas evolution in immersion tests and cytocompatibility were assessed. In addition, a novel in vitro immunological test using primary human lymphocytes was introduced. On PEO-treated WE43, a larger number of pores and microcracks, as well as increased roughness, were observed compared to untreated WE43. Hydrogen gas evolution after two weeks was reduced by 40.7% through PEO treatment, indicating a significantly reduced corrosion rate. In contrast to untreated WE43, PEO-treated WE43 exhibited excellent cytocompatibility. After incubation for three days, untreated WE43 killed over 90% of lymphocytes while more than 80% of the cells were still vital after incubation with the PEO-treated WE43. PEO-treated WE43 slightly stimulated the activation, proliferation and toxin (perforin and granzyme B) expression of CD8⁺ T cells. This study demonstrates that the combined assessment of corrosion, cytocompatibility and immunological effects on primary human lymphocytes provide a comprehensive and effective procedure for characterizing Mg variants with tailorable degradation and other features. PEO-treated WE43 is a promising candidate for further development as a degradable biomaterial. Full article

(This article belongs to the Special Issue Optimization of Biomaterials for Reconstructive and Regenerative Medicine)

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12 pages, 1954 KiB

Open AccessArticle

Marginal Adaptation and Microbial Leakage at Conometric Prosthetic Connections for Implant-Supported Single Crowns: An In Vitro Investigation

by Peter Gehrke, Philip Hartjen, Ralf Smeets, Martin Gosau, Ulrike Peters, Thomas Beikler, Carsten Fischer, Carolin Stolzer, Jürgen Geis-Gerstorfer, Paul Weigl and Sogand Schäfer

Int. J. Mol. Sci. 2021, 22(2), 881; https://doi.org/10.3390/ijms22020881 - 17 Jan 2021

Cited by 12 | Viewed by 3696

Abstract

Encouraging clinical results were reported on a novel cone-in-cone coupling for the fixation of dental implant-supported crowns (Acuris, Dentsply Sirona Implants, Mölndal, Sweden). However, the presence or absence of a microgap and a potential bacterial leakage at the conometric joint has not yet [...] Read more.

Encouraging clinical results were reported on a novel cone-in-cone coupling for the fixation of dental implant-supported crowns (Acuris, Dentsply Sirona Implants, Mölndal, Sweden). However, the presence or absence of a microgap and a potential bacterial leakage at the conometric joint has not yet been investigated. A misfit and a resulting gap between the conometric components could potentially serve as a bacterial reservoir that promotes plaque formation, which in turn may lead to inflammation of the peri-implant tissues. Thus, a two-fold study set-up was designed in order to evaluate the bidirectional translocation of bacteria along conometrically seated single crowns. On conometric abutments filled with a culture suspension of anaerobic bacteria, the corresponding titanium nitride-coated (TiN) caps were fixed by friction. Each system was sterilized and immersed in culture medium to provide an optimal environment for microbial growth. Positive and negative controls were prepared. Specimens were stored in an anaerobic workstation, and total and viable bacterial counts were determined. Every 48 h, samples were taken from the reaction tubes to inoculate blood agar plates and to isolate bacterial DNA for quantification using qrt-PCR. In addition, one Acuris test system was subjected to scanning electron microscopy (SEM) to evaluate the precision of fit of the conometric coupling and marginal crown opening. Throughout the observational period of one week, blood agar plates of the specimens showed no viable bacterial growth. qrt-PCR, likewise, yielded a result approaching zero with an amount of about 0.53 × 10⁻⁴ µg/mL DNA. While the luting gap/marginal opening between the TiN-cap and the ceramic crown was within the clinically acceptable range, the SEM analysis failed to identify a measurable microgap at the cone-in-cone junction. Within the limits of the in-vitro study it can be concluded that the Acuris conometric interface does not allow for bacterial translocation under non-dynamic loading conditions. Full article

(This article belongs to the Special Issue Optimization of Biomaterials for Reconstructive and Regenerative Medicine)

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14 pages, 1556 KiB

Open AccessArticle

Tailoring Pyro- and Orthophosphate Species to Enhance Stem Cell Adhesion to Phosphate Glasses

by Nigel De Melo, Lauren Murrell, Md Towhidul Islam, Jeremy J. Titman, Laura Macri-Pellizzeri, Ifty Ahmed and Virginie Sottile

Int. J. Mol. Sci. 2021, 22(2), 837; https://doi.org/10.3390/ijms22020837 - 15 Jan 2021

Cited by 4 | Viewed by 2786

Abstract

Phosphate-based glasses (PBGs) offer significant therapeutic potential due to their bioactivity, controllable compositions, and degradation rates. Several PBGs have already demonstrated their ability to support direct cell growth and in vivo cytocompatibility for bone repair applications. This study investigated development of PBG formulations [...] Read more.

Phosphate-based glasses (PBGs) offer significant therapeutic potential due to their bioactivity, controllable compositions, and degradation rates. Several PBGs have already demonstrated their ability to support direct cell growth and in vivo cytocompatibility for bone repair applications. This study investigated development of PBG formulations with pyro- and orthophosphate species within the glass system (40 − x)P₂O₅·(16 + x)CaO·20Na₂O·24MgO (x = 0, 5, 10 mol%) and their effect on stem cell adhesion properties. Substitution of phosphate for calcium revealed a gradual transition within the glass structure from Q² to Q⁰ phosphate species. Human mesenchymal stem cells were cultured directly onto discs made from three PBG compositions. Analysis of cells seeded onto the discs revealed that PBG with higher concentration of pyro- and orthophosphate content (61% Q¹ and 39% Q⁰) supported a 4.3-fold increase in adhered cells compared to glasses with metaphosphate connectivity (49% Q² and 51% Q¹). This study highlights that tuning the composition of PBGs to possess pyro- and orthophosphate species only, enables the possibility to control cell adhesion performance. PBGs with superior cell adhesion profiles represent ideal candidates for biomedical applications, where cell recruitment and support for tissue ingrowth are of critical importance for orthopaedic interventions. Full article

(This article belongs to the Special Issue Optimization of Biomaterials for Reconstructive and Regenerative Medicine)

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19 pages, 10217 KiB

Open AccessArticle

Comparison of the Translational Potential of Human Mesenchymal Progenitor Cells from Different Bone Entities for Autologous 3D Bioprinted Bone Grafts

by Anna-Klara Amler, Patrick H. Dinkelborg, Domenic Schlauch, Jacob Spinnen, Stefan Stich, Roland Lauster, Michael Sittinger, Susanne Nahles, Max Heiland, Lutz Kloke, Carsten Rendenbach, Benedicta Beck-Broichsitter and Tilo Dehne

Int. J. Mol. Sci. 2021, 22(2), 796; https://doi.org/10.3390/ijms22020796 - 14 Jan 2021

Cited by 22 | Viewed by 3716

Abstract

Reconstruction of segmental bone defects by autologous bone grafting is still the standard of care but presents challenges including anatomical availability and potential donor site morbidity. The process of 3D bioprinting, the application of 3D printing for direct fabrication of living tissue, opens [...] Read more.

Reconstruction of segmental bone defects by autologous bone grafting is still the standard of care but presents challenges including anatomical availability and potential donor site morbidity. The process of 3D bioprinting, the application of 3D printing for direct fabrication of living tissue, opens new possibilities for highly personalized tissue implants, making it an appealing alternative to autologous bone grafts. One of the most crucial hurdles for the clinical application of 3D bioprinting is the choice of a suitable cell source, which should be minimally invasive, with high osteogenic potential, with fast, easy expansion. In this study, mesenchymal progenitor cells were isolated from clinically relevant human bone biopsy sites (explant cultures from alveolar bone, iliac crest and fibula; bone marrow aspirates; and periosteal bone shaving from the mastoid) and 3D bioprinted using projection-based stereolithography. Printed constructs were cultivated for 28 days and analyzed regarding their osteogenic potential by assessing viability, mineralization, and gene expression. While viability levels of all cell sources were comparable over the course of the cultivation, cells obtained by periosteal bone shaving showed higher mineralization of the print matrix, with gene expression data suggesting advanced osteogenic differentiation. These results indicate that periosteum-derived cells represent a highly promising cell source for translational bioprinting of bone tissue given their superior osteogenic potential as well as their minimally invasive obtainability. Full article

(This article belongs to the Special Issue Optimization of Biomaterials for Reconstructive and Regenerative Medicine)

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16 pages, 2248 KiB

Open AccessArticle

Temporomandibular Joint Osteoarthritis: Regenerative Treatment by a Stem Cell Containing Advanced Therapy Medicinal Product (ATMP)—An In Vivo Animal Trial

by Robert Köhnke, Marcus Oliver Ahlers, Moritz Alexander Birkelbach, Florian Ewald, Michael Krueger, Imke Fiedler, Björn Busse, Max Heiland, Tobias Vollkommer, Martin Gosau, Ralf Smeets and Rico Rutkowski

Int. J. Mol. Sci. 2021, 22(1), 443; https://doi.org/10.3390/ijms22010443 - 5 Jan 2021

Cited by 22 | Viewed by 5943

Abstract

Temporomandibular joint osteoarthritis (TMJ-OA) is a chronic degenerative disease that is often characterized by progressive impairment of the temporomandibular functional unit. The aim of this randomized controlled animal trial was a comparative analysis regarding the chondroregenerative potency of intra-articular stem/stromal cell therapy. Four [...] Read more.

Temporomandibular joint osteoarthritis (TMJ-OA) is a chronic degenerative disease that is often characterized by progressive impairment of the temporomandibular functional unit. The aim of this randomized controlled animal trial was a comparative analysis regarding the chondroregenerative potency of intra-articular stem/stromal cell therapy. Four weeks after combined mechanical and biochemical osteoarthritis induction in 28 rabbits, therapy was initiated by a single intra-articular injection, randomized into the following groups: Group 1: AB Serum (ABS); Group 2: Hyaluronic acid (HA); Group 3: Mesenchymal stromal cells (STx.); Group 4: Mesenchymal stromal cells in hyaluronic acid (HA + STx.). After another 4 weeks, the animals were euthanized, followed by histological examination of the removed joints. The histological analysis showed a significant increase in cartilage thickness in the stromal cell treated groups (HA + STx. vs. ABS, p = 0.028; HA + ST.x vs. HA, p = 0.042; STx. vs. ABS, p = 0.036). Scanning electron microscopy detected a similar heterogeneity of mineralization and tissue porosity in the subchondral zone in all groups. The single intra-articular injection of a stem cell containing, GMP-compliant advanced therapy medicinal product for the treatment of iatrogen induced osteoarthritis of the temporomandibular joint shows a chondroregenerative effect. Full article

(This article belongs to the Special Issue Optimization of Biomaterials for Reconstructive and Regenerative Medicine)

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10 pages, 4192 KiB

Open AccessCommunication

The Topographical Optimization of 3D Microgroove Pattern Intervals for Ligamentous Cell Orientations: In Vitro

by Min Guk Kim and Chan Ho Park

Int. J. Mol. Sci. 2020, 21(24), 9358; https://doi.org/10.3390/ijms21249358 - 8 Dec 2020

Cited by 6 | Viewed by 2186

Abstract

Specific orientations of periodontal ligaments (PDLs) to tooth-root surface play an important role in offering positional stabilities of teeth, transmitting and absorbing various stresses under masticatory/occlusal loading conditions, or promoting tissue remodeling by mechanical stimulations to periodontal cells. However, it is still challenging [...] Read more.

Specific orientations of periodontal ligaments (PDLs) to tooth-root surface play an important role in offering positional stabilities of teeth, transmitting and absorbing various stresses under masticatory/occlusal loading conditions, or promoting tissue remodeling by mechanical stimulations to periodontal cells. However, it is still challenging to spatially control PDL orientations and collective PDL cell alignments using 3D scaffold architectures. Here, we investigated the optimization of scaffold topographies in order to control orientations of human PDL cells with predictability in in vitro. The 3D PDL-guiding architectures were designed by computer-aided design (CAD) and microgroove patterns on the scaffold surfaces were created with four different slice intervals such as 25.40 µm (μG-25), 19.05 µm (μG-19), 12.70 µm (μG-12), and 6.35 µm (μG-6) by the digital slicing step. After scaffold design and 3D wax printing, poly-ε-caprolactone (PCL) was casted into 3D printed molds and human PDL cells were cultured for 7 days. In the results, μG-25 with low vertical resolution can angularly organize seeded cells predictably rather than μG-6 created by the highest resolution for high surface quality (or smooth surface). Moreover, nuclear orientations and deformability were quantitatively analyzed and a significant correlation between microgroove pattern intervals and cell alignments was calculated for the topographic optimization. In conclusion, controllable microgroove intervals can specifically organize human PDL cells by 3D printing, which can create various surface topographies with structural consistence. The optimal surface topography (μG-25) can angularly guide human PDL cells, but 6.35 µm-thick patterns (μG-6) showed random organization of cell collectivity. Full article

(This article belongs to the Special Issue Optimization of Biomaterials for Reconstructive and Regenerative Medicine)

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15 pages, 7227 KiB

Open AccessArticle

Microporosities in 3D-Printed Tricalcium-Phosphate-Based Bone Substitutes Enhance Osteoconduction and Affect Osteoclastic Resorption

by Chafik Ghayor, Tse-Hsiang Chen, Indranil Bhattacharya, Mutlu Özcan and Franz E. Weber

Int. J. Mol. Sci. 2020, 21(23), 9270; https://doi.org/10.3390/ijms21239270 - 4 Dec 2020

Cited by 18 | Viewed by 3369

Abstract

Additive manufacturing is a key technology required to realize the production of a personalized bone substitute that exactly meets a patient’s need and fills a patient-specific bone defect. Additive manufacturing can optimize the inner architecture of the scaffold for osteoconduction, allowing fast and [...] Read more.

Additive manufacturing is a key technology required to realize the production of a personalized bone substitute that exactly meets a patient’s need and fills a patient-specific bone defect. Additive manufacturing can optimize the inner architecture of the scaffold for osteoconduction, allowing fast and reliable defect bridging by promoting rapid growth of new bone tissue into the scaffold. The role of scaffold microporosity/nanoarchitecture in osteoconduction remains elusive. To elucidate this relationship, we produced lithography-based osteoconductive scaffolds from tricalcium phosphate (TCP) with identical macro- and microarchitecture, but varied their nanoarchitecture/microporosity by ranging maximum sintering temperatures from 1000 °C to 1200 °C. After characterization of the different scaffolds’ microporosity, compression strength, and nanoarchitecture, we performed in vivo studies that showed that ingrowth of bone as an indicator of osteoconduction significantly decreased with decreasing microporosity. Moreover, at the 1200 °C peak sinter temperature and lowest microporosity, osteoclastic degradation of the material was inhibited. Thus, even for wide-open porous TCP-based scaffolds, a high degree of microporosity appears to be essential for optimal osteoconduction and creeping substitution, which can prevent non-unions, the major complication during bone regeneration procedures. Full article

(This article belongs to the Special Issue Optimization of Biomaterials for Reconstructive and Regenerative Medicine)

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11 pages, 6718 KiB

Open AccessArticle

Effects of Synthesis Conditions on the Formation of Si-Substituted Alpha Tricalcium Phosphates

by Katarzyna Szurkowska, Łukasz Szeleszczuk and Joanna Kolmas

Int. J. Mol. Sci. 2020, 21(23), 9164; https://doi.org/10.3390/ijms21239164 - 1 Dec 2020

Cited by 15 | Viewed by 2593

Abstract

Powders of α-TCP containing various amounts of silicon were synthesized by two different methods: Wet chemical precipitation and solid-state synthesis. The obtained powders were then physico–chemically studied using different methods: Scanning and transmission electron microscopy (TEM and SEM), energy-dispersive X-ray spectroscopy (EDS), powder [...] Read more.

Powders of α-TCP containing various amounts of silicon were synthesized by two different methods: Wet chemical precipitation and solid-state synthesis. The obtained powders were then physico–chemically studied using different methods: Scanning and transmission electron microscopy (TEM and SEM), energy-dispersive X-ray spectroscopy (EDS), powder X-ray diffractometry (PXRD), infrared and Raman spectroscopies (FT-IR and R), and solid-state nuclear magnetic resonance (ssNMR). The study showed that the method of synthesis affects the morphology of the obtained particles, the homogeneity of crystalline phase and the efficiency of Si substitution. Solid-state synthesis leads to particles with a low tendency to agglomerate compared to the precipitation method. However, the powders obtained by the solid-state method are less homogeneous and contain a significant amount of other crystalline phase, silicocarnotite (up to 7.33%). Moreover, the microcrystals from this method are more disordered. This might be caused by more efficient substitution of silicate ions: The silicon content of the samples obtained by the solid-state method is almost equal to the nominal values. Full article

(This article belongs to the Special Issue Optimization of Biomaterials for Reconstructive and Regenerative Medicine)

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14 pages, 3964 KiB

Open AccessArticle

Injectable Gel Form of a Decellularized Bladder Induces Adipose-Derived Stem Cell Differentiation into Smooth Muscle Cells In Vitro

by Victoria Moreno-Manzano, Daria Zaytseva-Zotova, Eric López-Mocholí, Álvaro Briz-Redón, Berit Løkensgard Strand and Ángel Serrano-Aroca

Int. J. Mol. Sci. 2020, 21(22), 8608; https://doi.org/10.3390/ijms21228608 - 15 Nov 2020

Cited by 22 | Viewed by 3177

Abstract

Biologic scaffolds composed of extracellular matrix components have been proposed to repair and reconstruct a variety of tissues in clinical and pre-clinical studies. Injectable gels can fill and conform any three-dimensional shape and can be delivered to sites of interest by minimally invasive [...] Read more.

Biologic scaffolds composed of extracellular matrix components have been proposed to repair and reconstruct a variety of tissues in clinical and pre-clinical studies. Injectable gels can fill and conform any three-dimensional shape and can be delivered to sites of interest by minimally invasive techniques. In this study, a biological gel was produced from a decellularized porcine urinary bladder by enzymatic digestion with pepsin. The enzymatic digestion was confirmed by visual inspection after dissolution in phosphate-buffered saline solution and Fourier-transform infrared spectroscopy. The rheological and biological properties of the gel were characterized and compared to those of the Matrigel^TM chosen as a reference material. The storage modulus G’ reached 19.4 ± 3.7 Pa for the 30 mg/mL digested decellularized bladder gels after ca. 3 h at 37 °C. The results show that the gel formed of the porcine urinary bladder favored the spontaneous differentiation of human and rabbit adipose-derived stem cells in vitro into smooth muscle cells to the detriment of cell proliferation. The results support the potential of the developed injectable gel for tissue engineering applications to reconstruct for instance the detrusor muscle part of the human urinary bladder. Full article

(This article belongs to the Special Issue Optimization of Biomaterials for Reconstructive and Regenerative Medicine)

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12 pages, 2730 KiB

Open AccessArticle

Time Dependency of Non-Thermal Oxygen Plasma and Ultraviolet Irradiation on Cellular Attachment and mRNA Expression of Growth Factors in Osteoblasts on Titanium and Zirconia Surfaces

by Linna Guo, Ziang Zou, Ralf Smeets, Lan Kluwe, Philip Hartjen, Claudio Cacaci, Martin Gosau and Anders Henningsen

Int. J. Mol. Sci. 2020, 21(22), 8598; https://doi.org/10.3390/ijms21228598 - 14 Nov 2020

Cited by 14 | Viewed by 2478

Abstract

Ultraviolet (UV) light and non-thermal plasma (NTP) are promising chair-side surface treatment methods to overcome the time-dependent aging of dental implant surfaces. After showing the efficiency of UV light and NTP treatment in restoring the biological activity of titanium and zirconia surfaces in [...] Read more.

Ultraviolet (UV) light and non-thermal plasma (NTP) are promising chair-side surface treatment methods to overcome the time-dependent aging of dental implant surfaces. After showing the efficiency of UV light and NTP treatment in restoring the biological activity of titanium and zirconia surfaces in vitro, the objective of this study was to define appropriate processing times for clinical use. Titanium and zirconia disks were treated by UV light and non-thermal oxygen plasma with increasing duration. Non-treated disks were set as controls. Murine osteoblast-like cells (MC3T3-E1) were seeded onto the treated or non-treated disks. After 2 and 24 h of incubation, the viability of cells on surfaces was assessed using an MTS assay. mRNA expression of vascular endothelial growth factor (VEGF) and hepatocyte growth factor (HGF) were assessed using real-time reverse transcription polymerase chain reaction analysis. Cellular morphology and attachment were observed using confocal microscopy. The viability of MC3T3-E1 was significantly increased in 12 min UV-light treated and 1 min oxygen NTP treated groups. VEGF relative expression reached the highest levels on 12 min UV-light and 1 min NTP treated surfaces of both disks. The highest levels of HGF relative expression were reached on 12 min UV light treated zirconia surfaces. However, cells on 12 and 16 min UV-light and NTP treated surfaces of both materials had a more widely spread cytoskeleton compared to control groups. Twelve min UV-light and one min non-thermal oxygen plasma treatment on titanium and zirconia may be the favored times in terms of increasing the viability, mRNA expression of growth factors and cellular attachment in MC3T3-E1 cells. Full article

(This article belongs to the Special Issue Optimization of Biomaterials for Reconstructive and Regenerative Medicine)

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14 pages, 5016 KiB

Open AccessArticle

Distinct Osteogenic Potentials of BMP-2 and FGF-2 in Extramedullary and Medullary Microenvironments

by Shuji Nosho, Ikue Tosa, Mitsuaki Ono, Emilio Satoshi Hara, Kei Ishibashi, Akihiro Mikai, Yukie Tanaka, Aya Kimura-Ono, Taishi Komori, Kenji Maekawa, Takuo Kuboki and Toshitaka Oohashi

Int. J. Mol. Sci. 2020, 21(21), 7967; https://doi.org/10.3390/ijms21217967 - 27 Oct 2020

Cited by 12 | Viewed by 3416

Abstract

Bone morphogenetic protein-2 (BMP-2) and fibroblast growth factor-2 (FGF-2) have been regarded as the major cytokines promoting bone formation, however, several studies have reported unexpected results with failure of bone formation or bone resorption of these growth factors. In this study, BMP-2 and [...] Read more.

Bone morphogenetic protein-2 (BMP-2) and fibroblast growth factor-2 (FGF-2) have been regarded as the major cytokines promoting bone formation, however, several studies have reported unexpected results with failure of bone formation or bone resorption of these growth factors. In this study, BMP-2 and FGF-2 adsorbed into atellocollagen sponges were transplanted into bone defects in the bone marrow-scarce calvaria (extramedullary environment) and bone marrow-abundant femur (medullary environment) for analysis of their in vivo effects not only on osteoblasts, osteoclasts but also on bone marrow cells. The results showed that BMP-2 induced high bone formation in the bone marrow-scarce calvaria, but induced bone resorption in the bone marrow-abundant femurs. On the other hand, FGF-2 showed opposite effects compared to those of BMP-2. Analysis of cellular dynamics revealed numerous osteoblasts and osteoclasts present in the newly-formed bone induced by BMP-2 in calvaria, but none were seen in either control or FGF-2-transplanted groups. On the other hand, in the femur, numerous osteoclasts were observed in the vicinity of the BMP-2 pellet, while a great number of osteoblasts were seen near the FGF-2 pellets or in the control group. Of note, FCM analysis showed that both BMP-2 and FGF-2 administrated in the femur did not significantly affect the hematopoietic cell population, indicating a relatively safe application of the two growth factors. Together, these results indicate that BMP-2 could be suitable for application in extramedullary bone regeneration, whereas FGF-2 could be suitable for application in medullary bone regeneration. Full article

(This article belongs to the Special Issue Optimization of Biomaterials for Reconstructive and Regenerative Medicine)

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18 pages, 3478 KiB

Open AccessArticle

Rose Bengal Crosslinking to Stabilize Collagen Sheets and Generate Modulated Collagen Laminates

by Stefanie Eckes, Joy Braun, Julia S. Wack, Ulrike Ritz, Daniela Nickel and Katja Schmitz

Int. J. Mol. Sci. 2020, 21(19), 7408; https://doi.org/10.3390/ijms21197408 - 8 Oct 2020

Cited by 6 | Viewed by 3723

Abstract

For medical application, easily accessible biomaterials with tailored properties are desirable. Collagen type I represents a biomaterial of choice for regenerative medicine and tissue engineering. Here, we present a simple method to modify the properties of collagen and to generate collagen laminates. We [...] Read more.

For medical application, easily accessible biomaterials with tailored properties are desirable. Collagen type I represents a biomaterial of choice for regenerative medicine and tissue engineering. Here, we present a simple method to modify the properties of collagen and to generate collagen laminates. We selected three commercially available collagen sheets with different thicknesses and densities and examined the effect of rose bengal and green light collagen crosslinking (RGX) on properties such as microstructure, swelling degree, mechanical stability, cell compatibility and drug release. The highest impact of RGX was measured for Atelocollagen, for which the swelling degree was reduced from 630% (w/w) to 520% (w/w) and thickness measured under force application increased from 0.014 mm to 0.455 mm, indicating a significant increase in mechanical stability. Microstructural analysis revealed that the sponge-like structure was replaced by a fibrous structure. While the initial burst effect during vancomycin release was not influenced by crosslinking, RGX increased cell proliferation on sheets of Atelocollagen and on Collagen Solutions. We furthermore demonstrate that RGX can be used to covalently attach different sheets to create materials with combined properties, making the modification and combination of readily available sheets with RGX an attractive approach for clinical application. Full article

(This article belongs to the Special Issue Optimization of Biomaterials for Reconstructive and Regenerative Medicine)

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13 pages, 3509 KiB

Open AccessArticle

In Vitro Feasibility Analysis of a New Sutureless Wound-Closure System Based on a Temperature-Regulated Laser and a Transparent Collagen Membrane for Laser Tissue Soldering (LTS)

by Moritz Alexander Birkelbach, Ralf Smeets, Imke Fiedler, Lan Kluwe, Martin Wehner, Tilmann Trebst and Philip Hartjen

Int. J. Mol. Sci. 2020, 21(19), 7104; https://doi.org/10.3390/ijms21197104 - 26 Sep 2020

Cited by 11 | Viewed by 3559

Abstract

For the post-surgical treatment of oral wounds and mucosal defects beyond a certain size, the gold standard is still an autologous skin or mucosal graft in combination with complex suturing techniques. A variety of techniques and biomaterials has been developed for sutureless wound [...] Read more.

For the post-surgical treatment of oral wounds and mucosal defects beyond a certain size, the gold standard is still an autologous skin or mucosal graft in combination with complex suturing techniques. A variety of techniques and biomaterials has been developed for sutureless wound closure including different tissue glues or collagen patches. However, no wound covering that enables for sutureless fixation has yet been introduced. Thus, a new system was developed that allows for sutureless wound covering including a transparent collagen membrane, which can be attached to the mucosa using a specially modified 2λ laser beam with integrated temperature sensors and serum albumin as bio-adhesive. The sutureless wound closure system was tested for its applicability and its cytocompatibility by an established in vitro model in the present study. The feasibility of the laser system was tested ex vivo on a porcine palate. The in vitro cytocompatibility tests excluded the potential release of toxic substances from the laser-irradiated collagen membrane and the bio-adhesive. The results of the ex vivo feasibility study using a porcine palate revealed satisfactory mean tensile strength of 1.2–1.5 N for the bonding of the membrane to the tissue fixed with laser of 980 nm. The results suggest that our newly developed laser-assisted wound closure system is a feasible approach and could be a first step on the way towards a laser based sutureless clinical application in tissue repair and oral surgery. Full article

(This article belongs to the Special Issue Optimization of Biomaterials for Reconstructive and Regenerative Medicine)

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19 pages, 4767 KiB

Open AccessArticle

Docosahexaenoic Acid-Loaded Polylactic Acid Core-Shell Nanofiber Membranes for Regenerative Medicine after Spinal Cord Injury: In Vitro and In Vivo Study

by Zhuo-Hao Liu, Yin-Cheng Huang, Chang-Yi Kuo, Chao-Ying Kuo, Chieh-Yu Chin, Ping K. Yip and Jyh-Ping Chen

Int. J. Mol. Sci. 2020, 21(19), 7031; https://doi.org/10.3390/ijms21197031 - 24 Sep 2020

Cited by 10 | Viewed by 3287

Abstract

Spinal cord injury (SCI) is associated with disability and a drastic decrease in quality of life for affected individuals. Previous studies support the idea that docosahexaenoic acid (DHA)-based pharmacological approach is a promising therapeutic strategy for the management of acute SCI. We postulated [...] Read more.

Spinal cord injury (SCI) is associated with disability and a drastic decrease in quality of life for affected individuals. Previous studies support the idea that docosahexaenoic acid (DHA)-based pharmacological approach is a promising therapeutic strategy for the management of acute SCI. We postulated that a nanostructured material for controlled delivery of DHA at the lesion site may be well suited for this purpose. Toward this end, we prepare drug-loaded fibrous mats made of core-shell nanofibers by electrospinning, which contained a polylactic acid (PLA) shell for encapsulation of DHA within the core, for delivery of DHA in situ. In vitro study confirmed sustained DHA release from PLA/DHA core-shell nanofiber membrane (CSNM) for up to 36 days, which could significantly increase neurite outgrowth from primary cortical neurons in 3 days. This is supported by the upregulation of brain-derived neurotropic factor (BDNF) and neurotrophin-3 (NT-3) neural marker genes from qRT-PCR analysis. Most importantly, the sustained release of DHA could significantly increase the neurite outgrowth length from cortical neuron cells in 7 days when co-cultured with PLA/DHA CSNM, compared with cells cultured with 3 μM DHA. From in vivo study with a SCI model created in rats, implantation of PLA/DHA CSNM could significantly improve neurological functions revealed by behavior assessment in comparison with the control (no treatment) and the PLA CSNM groups. According to histological analysis, PLA/DHA CSNM also effectively reduced neuron loss and increased serotonergic nerve sprouting. Taken together, the PLA/DHA CSNM may provide a nanostructured drug delivery system for DHA and contribute to neuroprotection and promoting neuroplasticity change following SCI. Full article

(This article belongs to the Special Issue Optimization of Biomaterials for Reconstructive and Regenerative Medicine)

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13 pages, 3280 KiB

Open AccessArticle

BMP-2/β-TCP Local Delivery for Bone Regeneration in MRONJ-Like Mouse Model

by Akihiro Mikai, Mitsuaki Ono, Ikue Tosa, Ha Thi Thu Nguyen, Emilio Satoshi Hara, Shuji Nosho, Aya Kimura-Ono, Kumiko Nawachi, Takeshi Takarada, Takuo Kuboki and Toshitaka Oohashi

Int. J. Mol. Sci. 2020, 21(19), 7028; https://doi.org/10.3390/ijms21197028 - 24 Sep 2020

Cited by 23 | Viewed by 4572

Abstract

Medication-related osteonecrosis of the jaw (MRONJ) is a severe pathological condition associated mainly with the long-term administration of bone resorption inhibitors, which are known to induce suppression of osteoclast activity and bone remodeling. Bone Morphogenetic Protein (BMP)-2 is known to be a strong [...] Read more.

Medication-related osteonecrosis of the jaw (MRONJ) is a severe pathological condition associated mainly with the long-term administration of bone resorption inhibitors, which are known to induce suppression of osteoclast activity and bone remodeling. Bone Morphogenetic Protein (BMP)-2 is known to be a strong inducer of bone remodeling, by directly regulating osteoblast differentiation and osteoclast activity. This study aimed to evaluate the effects of BMP-2 adsorbed onto beta-tricalcium phosphate (β-TCP), which is an osteoinductive bioceramic material and allows space retention, on the prevention and treatment of MRONJ in mice. Tooth extraction was performed after 3 weeks of zoledronate (ZA) and cyclophosphamide (CY) administration. For prevention studies, BMP-2/β-TCP was transplanted immediately after tooth extraction, and the mice were administered ZA and CY for an additional 4 weeks. The results showed that while the tooth extraction socket was mainly filled with a sparse tissue in the control group, bone formation was observed at the apex of the tooth extraction socket and was filled with a dense connective tissue rich in cellular components in the BMP-2/β-TCP transplanted group. For treatment studies, BMP-2/β-TCP was transplanted 2 weeks after tooth extraction, and bone formation was followed up for the subsequent 4 weeks under ZA and CY suspension. The results showed that although the tooth extraction socket was mainly filled with soft tissue in the control group, transplantation of BMP-2/β-TCP could significantly accelerate bone formation, as shown by immunohistochemical analysis for osteopontin, and reduce the bone necrosis in tooth extraction sockets. These data suggest that the combination of BMP-2/β-TCP could become a suitable therapy for the management of MRONJ. Full article

(This article belongs to the Special Issue Optimization of Biomaterials for Reconstructive and Regenerative Medicine)

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17 pages, 4022 KiB

Open AccessArticle

Influence of the Casting Concentration on the Mechanical and Optical Properties of FA/CaCl₂-Derived Silk Fibroin Membranes

by Alexander Kopp, Laura Schunck, Martin Gosau, Ralf Smeets, Simon Burg, Sandra Fuest, Nadja Kröger, Max Zinser, Sebastian Krohn, Mehdi Behbahani, Marius Köpf, Lisa Lauts and Rico Rutkowski

Int. J. Mol. Sci. 2020, 21(18), 6704; https://doi.org/10.3390/ijms21186704 - 13 Sep 2020

Cited by 8 | Viewed by 2835

Abstract

In this study, we describe the manufacturing and characterization of silk fibroin membranes derived from the silkworm Bombyx mori. To date, the dissolution process used in this study has only been researched to a limited extent, although it entails various potential advantages, such [...] Read more.

In this study, we describe the manufacturing and characterization of silk fibroin membranes derived from the silkworm Bombyx mori. To date, the dissolution process used in this study has only been researched to a limited extent, although it entails various potential advantages, such as reduced expenses and the absence of toxic chemicals in comparison to other conventional techniques. Therefore, the aim of this study was to determine the influence of different fibroin concentrations on the process output and resulting membrane properties. Casted membranes were thus characterized with regard to their mechanical, structural and optical assets via tensile testing, SEM, light microscopy and spectrophotometry. Cytotoxicity was evaluated using BrdU, XTT, and LDH assays, followed by live–dead staining. The formic acid (FA) dissolution method was proven to be suitable for the manufacturing of transparent and mechanically stable membranes. The fibroin concentration affects both thickness and transparency of the membranes. The membranes did not exhibit any signs of cytotoxicity. When compared to other current scientific and technical benchmarks, the manufactured membranes displayed promising potential for various biomedical applications. Further research is nevertheless necessary to improve reproducible manufacturing, including a more uniform thickness, less impurity and physiological pH within the membranes. Full article

(This article belongs to the Special Issue Optimization of Biomaterials for Reconstructive and Regenerative Medicine)

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19 pages, 7739 KiB

Open AccessArticle

Production of Injectable Marine Collagen-Based Hydrogel for the Maintenance of Differentiated Chondrocytes in Tissue Engineering Applications

by Salvatrice Rigogliuso, Monica Salamone, Enza Barbarino, Maria Barbarino, Aldo Nicosia and Giulio Ghersi

Int. J. Mol. Sci. 2020, 21(16), 5798; https://doi.org/10.3390/ijms21165798 - 12 Aug 2020

Cited by 27 | Viewed by 4106

Abstract

Cartilage is an avascular tissue with limited ability of self-repair. The use of autologous chondrocyte transplants represent an effective strategy for cell regeneration; however, preserving the differentiated state, which ensures the ability to regenerate damaged cartilage, represents the main challenge during in vitro [...] Read more.

Cartilage is an avascular tissue with limited ability of self-repair. The use of autologous chondrocyte transplants represent an effective strategy for cell regeneration; however, preserving the differentiated state, which ensures the ability to regenerate damaged cartilage, represents the main challenge during in vitro culturing. For this purpose, we produced an injectable marine collagen-based hydrogel, by mixing native collagen from the jellyfish Rhizostoma pulmo with hydroxy-phenyl-propionic acid (HPA)-functionalized marine gelatin. This biocompatible hydrogel formulation, due to the ability of enzymatically reticulate using horseradish peroxidase (HPR) and H₂O₂, gives the possibility of trap cells inside, in the absence of cytotoxic effects, during the cross-linking process. Moreover, it enables the modulation of the hydrogel stiffness merely varying the concentration of H₂O₂ without changes in the concentration of polymer precursors. The maintenance of differentiated chondrocytes in culture was then evaluated via morphological analysis of cell phenotype, GAG production and cytoskeleton organization. Additionally, gene expression profiling of differentiation/dedifferentiation markers provided evidence for the promotion of the chondrogenic gene expression program. This, combined with the biochemical properties of marine collagen, represents a promising strategy for maintaining in vitro the cellular phenotype in the aim of the use of autologous chondrocytes in regenerative medicine practices. Full article

(This article belongs to the Special Issue Optimization of Biomaterials for Reconstructive and Regenerative Medicine)

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17 pages, 2964 KiB

Open AccessArticle

Extracellular Vesicles-Loaded Fibrin Gel Supports Rapid Neovascularization for Dental Pulp Regeneration

by Siyuan Zhang, Anja Lena Thiebes, Franziska Kreimendahl, Stephan Ruetten, Eva Miriam Buhl, Michael Wolf, Stefan Jockenhoevel and Christian Apel

Int. J. Mol. Sci. 2020, 21(12), 4226; https://doi.org/10.3390/ijms21124226 - 13 Jun 2020

Cited by 40 | Viewed by 5042

Abstract

Rapid vascularization is required for the regeneration of dental pulp due to the spatially restricted tooth environment. Extracellular vesicles (EVs) released from mesenchymal stromal cells show potent proangiogenic effects. Since EVs suffer from rapid clearance and low accumulation in target tissues, an injectable [...] Read more.

Rapid vascularization is required for the regeneration of dental pulp due to the spatially restricted tooth environment. Extracellular vesicles (EVs) released from mesenchymal stromal cells show potent proangiogenic effects. Since EVs suffer from rapid clearance and low accumulation in target tissues, an injectable delivery system capable of maintaining a therapeutic dose of EVs over a longer period would be desirable. We fabricated an EV-fibrin gel composite as an in situ forming delivery system. EVs were isolated from dental pulp stem cells (DPSCs). Their effects on cell proliferation and migration were monitored in monolayers and hydrogels. Thereafter, endothelial cells and DPSCs were co-cultured in EV-fibrin gels and angiogenesis as well as collagen deposition were analyzed by two-photon laser microscopy. Our results showed that EVs enhanced cell growth and migration in 2D and 3D cultures. EV-fibrin gels facilitated vascular-like structure formation in less than seven days by increasing the release of VEGF. The EV-fibrin gel promoted the deposition of collagen I, III, and IV, and readily induced apoptosis during the initial stage of angiogenesis. In conclusion, we confirmed that EVs from DPSCs can promote angiogenesis in an injectable hydrogel in vitro, offering a novel and minimally invasive strategy for regenerative endodontic therapy. Full article

(This article belongs to the Special Issue Optimization of Biomaterials for Reconstructive and Regenerative Medicine)

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14 pages, 1332 KiB

Open AccessArticle

The Influence of Local Pamidronate Application on Alveolar Dimensional Preservation after Tooth Extraction—An Animal Experimental Study

by Frederic Kauffmann, Christian Höhne, Alexandre Thomas Assaf, Tobias Vollkommer, Jan Semmusch, Aline Reitmeier, Jamal Michel Stein, Max Heiland, Ralf Smeets and Rico Rutkowski

Int. J. Mol. Sci. 2020, 21(10), 3616; https://doi.org/10.3390/ijms21103616 - 20 May 2020

Cited by 7 | Viewed by 2726

Abstract

The aim of this randomized, controlled animal exploratory trial was to investigate the influence of local application of aminobisphosphonate pamidronate during the socket preservation procedure. Mandibular premolars were extracted in five Göttingen minipigs. Two animals underwent socket preservation using BEGO OSS (n = [...] Read more.

The aim of this randomized, controlled animal exploratory trial was to investigate the influence of local application of aminobisphosphonate pamidronate during the socket preservation procedure. Mandibular premolars were extracted in five Göttingen minipigs. Two animals underwent socket preservation using BEGO OSS (n = 8 sockets) and three animals using BEGO OSS + Pamifos (15 mg) (n = 12 sockets). After jaw impression, cast models (baseline, eight weeks postoperative) were digitized using an inLab X5 scanner (Dentsply Sirona) and the generated STL data were superimposed and analyzed with GOM Inspect 2018 (GOM, Braunschweig). After 16 weeks, the lower jaws were prepared and examined using standard histological methods. In the test group (BEGO OSS + pamidronate), buccooral dimensional loss was significantly lower, both vestibulary (−0.80 ± 0.57 mm vs. −1.92 ± 0.63 mm; p = 0.00298) and lingually (−1.36 ± 0.58 mm vs. −2.56 ± 0.65 mm; p = 0.00104) compared with the control group (BEGO OSS). The test group showed a significant difference between vestibular and lingual dimensional loss (p = 0.04036). Histology showed cortical and cancellous bone in the alveolar sockets without signs of local inflammation. Adjuvant application of pamidronate during socket preservation reduces alveolar dimensional loss significantly. Further investigations with regard to dose–response relationships, volume effects, side effects, and a verification of the suitability in combination with other bone substitute materials (BSMs) are necessary. Full article

(This article belongs to the Special Issue Optimization of Biomaterials for Reconstructive and Regenerative Medicine)

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22 pages, 6580 KiB

Open AccessArticle

Degradation, Bone Regeneration and Tissue Response of an Innovative Volume Stable Magnesium-Supported GBR/GTR Barrier Membrane

by Mike Barbeck, Lennart Kühnel, Frank Witte, Jens Pissarek, Clarissa Precht, Xin Xiong, Rumen Krastev, Nils Wegner, Frank Walther and Ole Jung

Int. J. Mol. Sci. 2020, 21(9), 3098; https://doi.org/10.3390/ijms21093098 - 28 Apr 2020

Cited by 39 | Viewed by 5783

Abstract

Introduction: Bioresorbable collagenous barrier membranes are used to prevent premature soft tissue ingrowth and to allow bone regeneration. For volume stable indications, only non-absorbable synthetic materials are available. This study investigates a new bioresorbable hydrofluoric acid (HF)-treated magnesium (Mg) mesh in a native [...] Read more.

Introduction: Bioresorbable collagenous barrier membranes are used to prevent premature soft tissue ingrowth and to allow bone regeneration. For volume stable indications, only non-absorbable synthetic materials are available. This study investigates a new bioresorbable hydrofluoric acid (HF)-treated magnesium (Mg) mesh in a native collagen membrane for volume stable situations. Materials and Methods: HF-treated and untreated Mg were compared in direct and indirect cytocompatibility assays. In vivo, 18 New Zealand White Rabbits received each four 8 mm calvarial defects and were divided into four groups: (a) HF-treated Mg mesh/collagen membrane, (b) untreated Mg mesh/collagen membrane (c) collagen membrane and (d) sham operation. After 6, 12 and 18 weeks, Mg degradation and bone regeneration was measured using radiological and histological methods. Results: In vitro, HF-treated Mg showed higher cytocompatibility. Histopathologically, HF-Mg prevented gas cavities and was degraded by mononuclear cells via phagocytosis up to 12 weeks. Untreated Mg showed partially significant more gas cavities and a fibrous tissue reaction. Bone regeneration was not significantly different between all groups. Discussion and Conclusions: HF-Mg meshes embedded in native collagen membranes represent a volume stable and biocompatible alternative to the non-absorbable synthetic materials. HF-Mg shows less corrosion and is degraded by phagocytosis. However, the application of membranes did not result in higher bone regeneration. Full article

(This article belongs to the Special Issue Optimization of Biomaterials for Reconstructive and Regenerative Medicine)

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19 pages, 8666 KiB

Open AccessArticle

The Impact of Lidocaine on Adipose-Derived Stem Cells in Human Adipose Tissue Harvested by Liposuction and Used for Lipotransfer

by Felix Grambow, Rico Rutkowski, Fred Podmelle, Katrin Schmoeckel, Florian Siegerist, Grzegorz Domanski, Matthias W. Schuster and Grazyna Domanska

Int. J. Mol. Sci. 2020, 21(8), 2869; https://doi.org/10.3390/ijms21082869 - 20 Apr 2020

Cited by 15 | Viewed by 4127

Abstract

The local anesthetic lidocaine, which has been used extensively during liposuction, has been reported to have cytotoxic effects and therefore would be unsuitable for use in autologous lipotransfer. We evaluated the effect of lidocaine on the distribution, number, and viability of adipose-derived stem [...] Read more.

The local anesthetic lidocaine, which has been used extensively during liposuction, has been reported to have cytotoxic effects and therefore would be unsuitable for use in autologous lipotransfer. We evaluated the effect of lidocaine on the distribution, number, and viability of adipose-derived stem cells (ASCs), preadipocytes, mature adipocytes, and leukocytes in the fatty and fluid portion of the lipoaspirate using antibody staining and flow cytometry analyses. Adipose tissue was harvested from 11 female patients who underwent liposuction. Abdominal subcutaneous fat tissue was infiltrated with tumescent local anesthesia, containing lidocaine on the left and lacking lidocaine on the right side of the abdomen, and harvested subsequently. Lidocaine had no influence on the relative distribution, cell number, or viability of ASCs, preadipocytes, mature adipocytes, or leukocytes in the stromal-vascular fraction. Assessing the fatty and fluid portions of the lipoaspirate, the fatty portions contained significantly more ASCs (p < 0.05), stem cells expressing the preadipocyte marker Pref-1 (p < 0.01 w/lidocaine, p < 0.05 w/o lidocaine), and mature adipocytes (p < 0.05 w/lidocaine, p < 0.01 w/o lidocaine) than the fluid portions. Only the fatty portion should be used for transplantation. This study found no evidence that would contraindicate the use of lidocaine in lipotransfer. Limitations of the study include the small sample size and the inclusion of only female patients. Full article

(This article belongs to the Special Issue Optimization of Biomaterials for Reconstructive and Regenerative Medicine)

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20 pages, 11141 KiB

Open AccessArticle

Tailored PCL Scaffolds as Skin Substitutes Using Sacrificial PVP Fibers and Collagen/Chitosan Blends

by Ali Reza Sadeghi-avalshahr, Samira Nokhasteh, Amir Mahdi Molavi, Najmeh Mohammad-pour and Mohammad Sadeghi

Int. J. Mol. Sci. 2020, 21(7), 2311; https://doi.org/10.3390/ijms21072311 - 27 Mar 2020

Cited by 50 | Viewed by 5245

Abstract

Electrospinning is a versatile technique for fabrication of made-on-purpose biomimetic scaffolds. In this study, optimized electrospun fibrous membranes were produced by simultaneous electrospinning of polycaprolactone (PCL) and polyvinylpyrrolidone (PVP), followed by the selective removal of PVP from the PCL/PVP mesh. After aminolysis, a [...] Read more.

Electrospinning is a versatile technique for fabrication of made-on-purpose biomimetic scaffolds. In this study, optimized electrospun fibrous membranes were produced by simultaneous electrospinning of polycaprolactone (PCL) and polyvinylpyrrolidone (PVP), followed by the selective removal of PVP from the PCL/PVP mesh. After aminolysis, a blend of collagen/chitosan was grafted on the surface. Physicochemical characterizations as well as in vitro evaluations were conducted using different methods. Successful cell infiltration into samples was observed. It seems that the positive trend of cell ingress originates from the proper pore size obtained after removal of pvp (from 4.46 μm before immersion in water to 33.55 μm after immersion in water for 24 h). Furthermore, grafting the surface with the collagen/chitosan blend rendered the scaffolds more biocompatible with improved attachment and spreading of keratinocyte cell lines (HaCaT). Viability evaluation through MTT assay for HDF cells did not reveal any cytotoxic effects. Antibacterial assay with Staphylococcus aureus as Gram-positive and Escherichia coli as Gram-negative species corroborated the bactericidal effects of chitosan utilized in the composition of the coated blend. The results of in vitro studies along with physicochemical characterizations reflect the great potentials of the produced samples as scaffolds for application in skin tissue engineering. Full article

(This article belongs to the Special Issue Optimization of Biomaterials for Reconstructive and Regenerative Medicine)

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Jump to: Research

24 pages, 57177 KiB

Open AccessReview

A Review of the Use of Microparticles for Cartilage Tissue Engineering

by Rachel J. Kulchar, Bridget R. Denzer, Bharvi M. Chavre, Mina Takegami and Jennifer Patterson

Int. J. Mol. Sci. 2021, 22(19), 10292; https://doi.org/10.3390/ijms221910292 - 24 Sep 2021

Cited by 22 | Viewed by 5452

Abstract

Tissue and organ failure has induced immense economic and healthcare concerns across the world. Tissue engineering is an interdisciplinary biomedical approach which aims to address the issues intrinsic to organ donation by providing an alternative strategy to tissue and organ transplantation. This review [...] Read more.

Tissue and organ failure has induced immense economic and healthcare concerns across the world. Tissue engineering is an interdisciplinary biomedical approach which aims to address the issues intrinsic to organ donation by providing an alternative strategy to tissue and organ transplantation. This review is specifically focused on cartilage tissue. Cartilage defects cannot readily regenerate, and thus research into tissue engineering approaches is relevant as a potential treatment option. Cells, scaffolds, and growth factors are three components that can be utilized to regenerate new tissue, and in particular recent advances in microparticle technology have excellent potential to revolutionize cartilage tissue regeneration. First, microspheres can be used for drug delivery by injecting them into the cartilage tissue or joint space to reduce pain and stimulate regeneration. They can also be used as controlled release systems within tissue engineering constructs. Additionally, microcarriers can act as a surface for stem cells or chondrocytes to adhere to and expand, generating large amounts of cells, which are necessary for clinically relevant cell therapies. Finally, a newer application of microparticles is to form them together into granular hydrogels to act as scaffolds for tissue engineering or to use in bioprinting. Tissue engineering has the potential to revolutionize the space of cartilage regeneration, but additional research is needed to allow for clinical translation. Microparticles are a key enabling technology in this regard. Full article

(This article belongs to the Special Issue Optimization of Biomaterials for Reconstructive and Regenerative Medicine)

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15 pages, 2308 KiB

Open AccessReview

Hydrogel Encapsulation of Mesenchymal Stem Cells and Their Derived Exosomes for Tissue Engineering

by Parisa Khayambashi, Janaki Iyer, Sangeeth Pillai, Akshaya Upadhyay, Yuli Zhang and Simon D. Tran

Int. J. Mol. Sci. 2021, 22(2), 684; https://doi.org/10.3390/ijms22020684 - 12 Jan 2021

Cited by 124 | Viewed by 12256

Abstract

Tissue engineering has been an inveterate area in the field of regenerative medicine for several decades. However, there remains limitations to engineer and regenerate tissues. Targeted therapies using cell-encapsulated hydrogels, such as mesenchymal stem cells (MSCs), are capable of reducing inflammation and increasing [...] Read more.

Tissue engineering has been an inveterate area in the field of regenerative medicine for several decades. However, there remains limitations to engineer and regenerate tissues. Targeted therapies using cell-encapsulated hydrogels, such as mesenchymal stem cells (MSCs), are capable of reducing inflammation and increasing the regenerative potential in several tissues. In addition, the use of MSC-derived nano-scale secretions (i.e., exosomes) has been promising. Exosomes originate from the multivesicular division of cells and have high therapeutic potential, yet neither self-replicate nor cause auto-immune reactions to the host. To maintain their biological activity and allow a controlled release, these paracrine factors can be encapsulated in biomaterials. Among the different types of biomaterials in which exosome infusion is exploited, hydrogels have proven to be the most user-friendly, economical, and accessible material. In this paper, we highlight the importance of MSCs and MSC-derived exosomes in tissue engineering and the different biomaterial strategies used in fabricating exosome-based biomaterials, to facilitate hard and soft tissue engineering. Full article

(This article belongs to the Special Issue Optimization of Biomaterials for Reconstructive and Regenerative Medicine)

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19 pages, 4459 KiB

Open AccessReview

How Thick Is the Oral Mucosa around Implants after Augmentation with Different Materials: A Systematic Review of the Effectiveness of Substitute Matrices in Comparison to Connective Tissue Grafts

by Martin Lissek, Martin Boeker and Arndt Happe

Int. J. Mol. Sci. 2020, 21(14), 5043; https://doi.org/10.3390/ijms21145043 - 17 Jul 2020

Cited by 23 | Viewed by 4077

Abstract

This systematic review aimed to assess the effectiveness of xenogeneic collagen matrices (XCMs) and acellular dermal matrices (ADMs) in comparison to connective tissue grafts (CTGs) for the augmentation of oral mucosa around dental implants. MEDLINE and the Web of Science were searched for [...] Read more.

This systematic review aimed to assess the effectiveness of xenogeneic collagen matrices (XCMs) and acellular dermal matrices (ADMs) in comparison to connective tissue grafts (CTGs) for the augmentation of oral mucosa around dental implants. MEDLINE and the Web of Science were searched for clinical studies that compared substitute materials for the augmentation of oral mucosa to the subepithelial connective tissue graft around dental implants during or after implantation. The review was conducted according to the recommendations of the PRISMA statement. From an initial search result set of 1050 references, seven articles were included in the review. The study designs were heterogeneous, so no meta-analysis could be performed. Both the CTG and either type of substitute material resulted in increased mucosal thickness. Four studies showed no significant difference, while three demonstrated a significant difference, favoring the CTGs over alternative materials. Soft tissue augmentation around dental implants is a safe procedure and leads to thicker mucosal tissue. The subepithelial connective tissue graft can still be regarded as the gold standard, but substitute materials may be an acceptable alternative in some situations, such as for pain-sensitive patients, among inexperienced surgeons, and for sites with an already thick biotype. Full article

(This article belongs to the Special Issue Optimization of Biomaterials for Reconstructive and Regenerative Medicine)

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