Editor’s Choice Articles

Background and Objectives: Periodontal disease (PD) is a multifactorial oral disease regularly caused by bacterial biofilms. Silver nanoparticles (AgNP) have offered good antimicrobial activity; moreover, there is no available scientific information related to their antimicrobial effects in biofilms from patients with PD. This study reports the bactericidal activity of AgNP against oral biofilms related to PD. Materials and Methods: AgNP of two average particle sizes were prepared and characterized. Sixty biofilms were collected from patients with (30 subjects) and without PD (30 subjects). Minimal inhibitory concentrations of AgNP were calculated and the distribution of bacterial species was defined by polymerase chain reaction. Results: Well-dispersed sizes of AgNP were obtained (5.4 ± 1.3 and 17.5 ± 3.4 nm) with an adequate electrical stability (−38.2 ± 5.8 and −32.6 ± 5.4 mV, respectively). AgNP showed antimicrobial activities for all oral samples; however, the smaller AgNP had significantly the most increased bactericidal effects (71.7 ± 39.1 µg/mL). The most resistant bacteria were found in biofilms from PD subjects (p < 0.05). P. gingivalis, T. denticola, and T. forsythia were present in all PD biofilms (100%). Conclusions: The AgNP showed efficient bactericidal properties as an alternative therapy for the control or progression of PD. Full article

This work proposes a sonochemical biosynthesis of magnetoplasmonic nanostructures of Fe₃O₄ decorated with Au and Ag. The magnetoplasmonic systems, such as Fe₃O₄ and Fe₃O₄-Ag, were characterized structurally and magnetically. The structural characterizations reveal the magnetite structures as the primary phase. Noble metals, such as Au and Ag, are present in the sample, resulting in a structure-decorated type. The magnetic measurements indicate the superparamagnetic behavior of the Fe₃O₄-Ag and Fe₃O₄-Au nanostructures. The characterizations were carried out by X-ray diffraction and scanning electron microscopy. Complementarily, antibacterial and antifungal assays were carried out to evaluate the potential properties and future applications in biomedicine. Full article

Background: Tissue engineering and cell therapy have been the focus of investigations on how to treat challenging bone defects. This study aimed to produce and characterize a P(VDF-TrFE)/BaTiO₃ scaffold and evaluate the effect of mesenchymal stem cells (MSCs) combined with this scaffold and photobiomodulation (PBM) on bone repair. Methods and results: P(VDF-TrFE)/BaTiO₃ was synthesized using an electrospinning technique and presented physical and chemical properties suitable for bone tissue engineering. This scaffold was implanted in rat calvarial defects (unilateral, 5 mm in diameter) and, 2 weeks post-implantation, MSCs were locally injected into these defects (n = 12/group). Photobiomodulation was then applied immediately, and again 48 and 96 h post-injection. The μCT and histological analyses showed an increment in bone formation, which exhibited a positive correlation with the treatments combined with the scaffold, with MSCs and PBM inducing more bone repair, followed by the scaffold combined with PBM, the scaffold combined with MSCs, and finally the scaffold alone (ANOVA, p ≤ 0.05). Conclusions: The P(VDF-TrFE)/BaTiO₃ scaffold acted synergistically with MSCs and PBM to induce bone repair in rat calvarial defects. These findings emphasize the need to combine a range of techniques to regenerate large bone defects and provide avenues for further investigations on innovative tissue engineering approaches. Full article

Polymeric heart valves (PHVs) are a promising and more affordable alternative to mechanical heart valves (MHVs) and bioprosthetic heart valves (BHVs). Materials with good durability and biocompatibility used for PHVs have always been the research focus in the field of prosthetic heart valves for many years, and leaflet thickness is a major design parameter for PHVs. The study aims to discuss the relationship between material properties and valve thickness, provided that the basic functions of PHVs are qualified. The fluid−structure interaction (FSI) approach was employed to obtain a more reliable solution of the effective orifice area (EOA), regurgitant fraction (RF), and stress and strain distribution of the valves with different thicknesses under three materials: Carbothane PC−3585A, xSIBS and SIBS−CNTs. This study demonstrates that the smaller elastic modulus of Carbothane PC−3585A allowed for a thicker valve (>0.3 mm) to be produced, while for materials with an elastic modulus higher than that of xSIBS (2.8 MPa), a thickness less than 0.2 mm would be a good attempt to meet the RF standard. What is more, when the elastic modulus is higher than 23.9 MPa, the thickness of the PHV is recommended to be 0.l–0.15 mm. Reducing the RF is one of the directions of PHV optimization in the future. Reducing the thickness and improving other design parameters are reliable means to reduce the RF for materials with high and low elastic modulus, respectively. Full article

The utilization of cytosolic protein delivery is a promising approach for treating various diseases by replacing dysfunctional proteins. Despite the development of various nanoparticle-based intracellular protein delivery methods, the complicated chemical synthesis of the vector, loading efficiency and endosomal escape efficiency of proteins remain a great challenge. Recently, 9-fluorenylmethyloxycarbonyl (Fmoc)-modified amino acid derivatives have been used to self-assemble into supramolecular nanomaterials for drug delivery. However, the instability of the Fmoc group in aqueous medium restricts its application. To address this issue, the Fmoc ligand neighboring arginine was substituted for dibenzocyclooctyne (DBCO) with a similar structure to Fmoc to obtain stable DBCO-functionalized L-arginine derivative (DR). Azide-modified triethylamine (crosslinker C) was combined with DR to construct self-assembled DRC via a click chemical reaction for delivering various proteins, such as BSA and saporin (SA), into the cytosol of cells. The hyaluronic-acid-coated DRC/SA was able to not only shield the cationic toxicity, but also enhance the intracellular delivery efficiency of proteins by targeting CD44 overexpression on the cell membrane. The DRC/SA/HA exhibited higher growth inhibition efficiency and lower IC₅₀ compared to DRC/SA toward various cancer cell lines. In conclusion, DBCO-functionalized L-arginine derivative represents an excellent potential vector for protein-based cancer therapy. Full article

Engineering synthetic hydrogels for the repair and augmentation of load-bearing soft tissues with simultaneously high-water content and mechanical strength is a long-standing challenge. Prior formulations to enhance the strength have involved using chemical crosslinkers where residues remain a risk for implantation or complex processes such as freeze-casting and self-assembly, requiring specialised equipment and technical expertise to manufacture reliably. In this study, we report for the first time that the tensile strength of high-water content (>60 wt.%), biocompatible polyvinyl alcohol hydrogels can exceed 1.0 MPa through a combination of facile manufacturing strategies via physical crosslinking, mechanical drawing, post-fabrication freeze drying, and deliberate hierarchical design. It is anticipated that the findings in this paper can also be used in conjunction with other strategies to enhance the mechanical properties of hydrogel platforms in the design and construction of synthetic grafts for load-bearing soft tissues. Full article

Treatment of large segmental bone loss caused by fractures, osteomyelitis, and non-union results in expenses of around USD 300,000 per case. Moreover, the worst-case scenario results in amputation in 10% to 14.5% of cases. Biomaterials, cells, and regulatory elements are employed in bone tissue engineering (BTE) to create biosynthetic bone grafts with effective functionalization that can aid in the restoration of such fractured bones, preventing amputation and alleviating expenses. Chitin (CT) and chitosan (CS) are two of the most prevalent natural biopolymers utilized in the fields of biomaterials and BTE. To offer the structural and biochemical cues for augmenting bone formation, CT and CS can be employed alone or in combination with other biomaterials in the form of nanofibers (NFs). When compared with several fabrication methods available to produce scaffolds, electrospinning is regarded as superior since it enables the development of nanostructured scaffolds utilizing biopolymers. Electrospun nanofibers (ENFs) offer unique characteristics, including morphological resemblance to the extracellular matrix, high surface-area-to-volume ratio, permeability, porosity, and stability. This review elaborates on the recent strategies employed utilizing CT and CS ENFs and their biocomposites in BTE. We also summarize their implementation in supporting and delivering an osteogenic response to treat critical bone defects and their perspectives on rejuvenation. The CT- and CS-based ENF composite biomaterials show promise as potential constructions for bone tissue creation. Full article

Black phosphorus (BP), an emerging two-dimensional material with unique optical, thermoelectric, and mechanical properties, has been proposed as bioactive material for tissue engineering. However, its toxic effects on physiological systems remain obscure. The present study investigated the cytotoxicity of BP to vascular endothelial cells. BP nanosheets (BPNSs) with a diameter of 230 nm were fabricated via a classical liquid-phase exfoliation method. Human umbilical vein endothelial cells (HUVECs) were used to determine the cytotoxicity induced by BPNSs (0.31–80 μg/mL). When the concentrations were over 2.5 μg/mL, BPNSs adversely affected the cytoskeleton and cell migration. Furthermore, BPNSs caused mitochondrial dysfunction and generated excessive intercellular reactive oxygen species (ROS) at tested concentrations after 24 h. BPNSs could influence the expression of apoptosis-related genes, including the P53 and BCL-2 family, resulting in the apoptosis of HUVECs. Therefore, the viability and function of HUVECs were adversely influenced by the concentration of BPNSs over 2.5 μg/mL. These findings provide significant information for the potential applications of BP in tissue engineering. Full article

Uncontrolled diabetes is characterized by aberrant inflammatory reactions and increased collagenolysis. We have reported that it accelerates the degradation of implanted collagen membranes (CM), thus compromising their function in regenerative procedures. In recent years, a group of physiological anti-inflammatory agents called specialized pro-resolving lipid mediators (SPMs) have been tested as a treatment for various inflammatory conditions, either systemically or locally, via medical devices. Yet, no study has tested their effect on the fate of the biodegradable material itself. Here, we measured the in vitro release over time of 100 or 800 ng resolvin D1 (RvD1) incorporated into CM discs. In vivo, diabetes was induced in rats with streptozotocin, while buffer-injected (normoglycemic) rats served as controls. Resolvins (100 or 800 ng of RvD1 or RvE1) were added to biotin-labeled CM discs, which were implanted sub-periosteally over the calvaria of rats. Membrane thickness, density, and uniformity were determined by quantitative histology after 3 weeks. In vitro, significant amounts of RvD1 were released over 1–8 days, depending on the amount loaded. In vivo, CMs from diabetic animals were thinner, more porous, and more variable in thickness and density. The addition of RvD1 or RvE1 improved their regularity, increased their density, and reduced their invasion by the host tissue significantly. We conclude that addition of resolvins to biodegradable medical devices can protect them from excessive degradation in systemic conditions characterized by high degree of collagenolysis. Full article

In this study, we fabricated adhesive patches from silkworm-regenerated silk and DNA to safeguard human skin from the sun’s rays. The patches are realized by exploiting the dissolution of silk fibers (e.g., silk fibroin (SF)) and salmon sperm DNA in formic acid and CaCl₂ solutions. Infrared spectroscopy is used to investigate the conformational transition of SF when combined with DNA; the results indicated that the addition of DNA provides an increase in the SF crystallinity. UV–Visible absorption and circular dichroism spectroscopy showed strong absorption in the UV region and the presence of B-form of DNA once dispersed in the SF matrix, respectively. Water absorption measurements as well as thermal dependence of water sorption and thermal analysis, suggested the stability of the fabricated patches. Biological results on cellular viability (MTT assay) of keratinocyte HaCaT cells after exposures to the solar spectrum showed that both SF and SF/DNA patches are photo-protective by increasing the cellular viability of keratinocytes after UV component exposure. Overall, these SF/DNA patches promise applications in wound dressing for practical biomedical purposes. Full article

The aim of this research was to evaluate the abrasive dentin wear that can be induced by three commercial whitening toothpastes following a tooth-brushing simulation (TBS) corresponding to a three-month period. Sixty human canines were selected, and the roots were separated from the crowns. Then the roots were randomly divided into six groups (n = 10) and were submitted to TBS using the following slurries: Group 1—deionized water (RDA = 5); Group 2—ISO dentifrice slurry (RDA = 100); Group 3—a regular toothpaste (RDA = 70); Group 4—a charcoal-containing whitening toothpaste; Group 5—a whitening toothpaste containing blue covasorb and hydrated silica; and Group 6—a whitening toothpaste containing microsilica. Following TBS, surface loss and surface roughness changes were evaluated using confocal microscopy. Additionally, surface morphology and mineral content changes were observed using scanning electron microscopy and energy-dispersive X-ray spectroscopy. The deionized water group presented the lowest surface loss (p < 0.05), while the charcoal-containing toothpaste presented the highest surface loss, followed by ISO dentifrice slurry (p < 0.001). Blue-covasorb-containing and regular toothpastes did not present statistically significant differences (p = 0.245), and neither didmicrosilica-containing toothpaste or ISO dentifrice slurry (p = 0.112). The surface height parameters and surface morphology changes of the experimental groups followed the surface loss patterns, while no differences were detected in mineral content after TBS.Although the charcoal-containing toothpaste exhibited the highest abrasive wear to dentin, according to ISO 11609, all the tested toothpastes exhibited appropriate abrasive behavior towards dentin. Full article

Heart failure is the leading cause of death in the US and worldwide. Despite modern therapy, challenges remain to rescue the damaged organ that contains cells with a very low proliferation rate after birth. Developments in tissue engineering and regeneration offer new tools to investigate the pathology of cardiac diseases and develop therapeutic strategies for heart failure patients. Tissue -engineered cardiac scaffolds should be designed to provide structural, biochemical, mechanical, and/or electrical properties similar to native myocardium tissues. This review primarily focuses on the mechanical behaviors of cardiac scaffolds and their significance in cardiac research. Specifically, we summarize the recent development of synthetic (including hydrogel) scaffolds that have achieved various types of mechanical behavior—nonlinear elasticity, anisotropy, and viscoelasticity—all of which are characteristic of the myocardium and heart valves. For each type of mechanical behavior, we review the current fabrication methods to enable the biomimetic mechanical behavior, the advantages and limitations of the existing scaffolds, and how the mechanical environment affects biological responses and/or treatment outcomes for cardiac diseases. Lastly, we discuss the remaining challenges in this field and suggestions for future directions to improve our understanding of mechanical control over cardiac function and inspire better regenerative therapies for myocardial restoration. Full article

The development of 3D-printed crown resin materials with improved mechanical and physical properties is an area of growing interest in dentistry. This study aimed to develop a 3D-printed crown resin material modified with zirconia glass (ZG) and glass silica (GS) microfillers to enhance overall mechanical and physical properties. A total of 125 specimens were created and divided into five groups: control unmodified resin, 5% either ZG or GS reinforced 3D-printed resin, and 10% either ZG or GS reinforced 3D-printed resin. The fracture resistance, surface roughness, and translucency parameter were measured, and fractured crowns were studied under a scanning electron microscope. The results showed that 3D-printed parts that were strengthened with ZG and GS microfillers demonstrated comparable mechanical performance to unmodified crown resin but resulted in greater surface roughness, and only the group that contained 5% ZG showed an increase in translucency. However, it should be noted that increased surface roughness may impact the aesthetics of the crowns, and further optimisation of microfillers concentrations may be necessary. These findings suggest that the newly developed dental-based resins that incorporate microfillers could be suitable for clinical applications, but further studies are necessary to optimise the nanoparticle concentrations and investigate their long-term clinical outcomes. Full article

Bone fractures and bone defects affect millions of people every year. Metal implants for bone fracture fixation and autologous bone for defect reconstruction are used extensively in treatment of these pathologies. Simultaneously, alternative, sustainable, and biocompatible materials are being researched to improve existing practice. Wood as a biomaterial for bone repair has not been considered until the last 50 years. Even nowadays there is not much research on solid wood as a biomaterial in bone implants. A few species of wood have been investigated. Different techniques of wood preparation have been proposed. Simple pre-treatments such as boiling in water or preheating of ash, birch and juniper woods have been used initially. Later researchers have tried using carbonized wood and wood derived cellulose scaffold. Manufacturing implants from carbonized wood and cellulose requires more extensive wood processing—heat above 800 °C and chemicals to extract cellulose. Carbonized wood and cellulose scaffolds can be combined with other materials, such as silicon carbide, hydroxyapatite, and bioactive glass to improve biocompatibility and mechanical durability. Throughout the publications wood implants have provided good biocompatibility and osteoconductivity thanks to wood’s porous structure. Full article

Multiphasic scaffolds that combine different architectural, physical, and biological properties are the best option for the regeneration of complex tissues such as the periodontium. Current developed scaffolds generally lack architectural accuracy and rely on multistep manufacturing, which is difficult to implement for clinical applications. In this context, direct-writing electrospinning (DWE) represents a promising and rapid technique for developing thin 3D scaffolds with controlled architecture. The current study aimed to elaborate a biphasic scaffold using DWE based on two polycaprolactone solutions with interesting properties for bone and cement regeneration. One of the two scaffold parts contained hydroxyapatite nanoparticles (HAP) and the other contained the cementum protein 1 (CEMP1). After morphological characterizations, the elaborated scaffolds were assessed regarding periodontal ligament (PDL) cells in terms of cell proliferation, colonization, and mineralization ability. The results demonstrated that both HAP- and CEMP1-functionalized scaffolds were colonized by PDL cells and enhanced mineralization ability compared to unfunctionalized scaffolds, as revealed by alizarin red staining and OPN protein fluorescent expression. Taken together, the current data highlighted the potential of functional and organized scaffolds to stimulate bone and cementum regeneration. Moreover, DWE could be used to develop smart scaffolds with the ability to spatially control cellular orientation with suitable cellular activity at the micrometer scale, thereby enhancing periodontal and other complex tissue regeneration. Full article

(1) Background: Coronal microleakage can lead to endodontic treatment failure. This study aimed to compare the sealing ability of different temporary restorative materials used during endodontic treatment. (2) Methods: Eighty sheep incisors were collected, uniformized in length, and access cavities were performed, except for in the negative control group, where the teeth were left intact. The teeth were divided into six different groups. In the positive control group, the access cavity was made and left empty. In the experimental groups, access cavities were restored with three different temporary materials (IRM^®, Ketac™ Silver, and Cavit™) and with a definitive restorative material (Filtek Supreme™). The teeth were submitted to thermocycling, and two and four weeks later, they were infiltrated with ^99mTcNaO₄, and nuclear medicine imaging was performed. (3) Results: Filtek Supreme™ obtained the lowest infiltration values. Regarding the temporary materials, at two weeks, Ketac™ Silver presented the lowest infiltration, followed by IRM^®, whereas Cavit™ presented the highest infiltration. At four weeks, Ketac™ Silver remained with the lowest values, whereas Cavit™ decreased the infiltration, comparable to IRM^®. (4) Conclusion: Regarding temporary materials, Ketac™ Silver had the lowest infiltration at 2 and 4 weeks, whereas the highest infiltration was found in the Cavit™ group at two weeks and in the IRM^® group at 4 weeks. Full article

Concentrated growth factors (CGFs) are widely used in surgery with bone grafting, but the release of growth factors from CGFs is rapid. RADA16, a self-assembling peptide, can form a scaffold that is similar to the extracellular matrix. Based on the properties of RADA16 and CGF, we hypothesized that the RADA16 nanofiber scaffold hydrogel could enhance the function of CGFs and that the RADA16 nanofiber scaffold hydrogel-wrapped CGFs (RADA16-CGFs) would perform a good osteoinductive function. This study aimed to investigate the osteoinductive function of RADA16-CGFs. Scanning electron microscopy, rheometry, and ELISA were performed, and MC3T3-E1 cells were used to test cell adhesion, cytotoxicity, and mineralization after administration with RADA16-CGFs. We found that RADA16 endowed with the sustained release of growth factors from CGFs, which can help maximize the function of CGFs in osteoinduction. The application of the atoxic RADA16 nanofiber scaffold hydrogel with CGFs can be a new therapeutic strategy for the treatment of alveolar bone loss and other problems that require bone regeneration. Full article

Astrocytes, highly specialized glial cells, play a critical role in neuronal function. Variations in brain extracellular matrix (ECM) during development and disease can significantly alter astrocyte cell function. Age-related changes in ECM properties have been linked to neurodegenerative diseases such as Alzheimer’s disease. The goal of this study was to develop hydrogel-based biomimetic ECM models with varying stiffness and evaluate the effects of ECM composition and stiffness on astrocyte cell response. Xeno-free ECM models were synthesized by combining varying ratios of human collagen and thiolated hyaluronic acid (HA) crosslinked with polyethylene glycol diacrylate. Results showed that modulating ECM composition yielded hydrogels with varying stiffnesses that match the stiffness of the native brain ECM. Collagen-rich hydrogels swell more and exhibit greater stability. Higher metabolic activity and greater cell spreading was observed in hydrogels with lower HA. Soft hydrogels trigger astrocyte activation indicated by greater cell spreading, high GFAP expression and low ALDH1L1 expression. This work presents a baseline ECM model to investigate the synergistic effects of ECM composition and stiffness on astrocytes, which could be further developed to identify key ECM biomarkers and formulate new therapies to alleviate the impact of ECM changes on the onset and progression of neurodegenerative diseases. Full article

Currently, 3D print is becoming more common in all branches of medicine, including dentistry. Some novel resins, such as BioMed Amber (Formlabs), are used and incorporated to more advanced techniques. The aims of the study were to check whether or not polishing and/or artificial aging influences the properties of the 3D-printed resin. A total of 240 specimens of BioMed Resin were printed. Two shapes (rectangular and dumbbell) were prepared. Of each shape, 120 specimens were divided into four groups each (with no influence, after polishing only, after artificial aging only, and after both polishing and artificial aging). Artificial aging took place in water at the temperature of 37 °C for 90 days. For testing, the universal testing machine (Z10-X700, AML Instruments, Lincoln, UK) was used. The axial compression was performed with the speed of 1mm/min. The tensile modulus was measured with the constant speed of 5 mm/min. The highest resistance to compression and tensile test were observed in the specimens that were neither polished nor aged (0.88 ± 0.03 and 2.88 ± 0.26, respectively). The lowest resistance to compression was observed in the specimens that were not polished, but aged (0.70 ± 0.02). The lowest results of the tensile test were observed when specimens were both polished and aged (2.05 ± 0.28). Both polishing and artificial aging weakened the mechanical properties of the BioMed Amber resin. The compressive modulus changed much with or without polishing. The tensile modulus differed in specimens that were either polished or aged. The application of both did not change the properties when compared to the polished or aged probes only. Full article

Opuntia Ficus-indica, or nopal, is traditionally used for its medicinal properties in Mexico. This study aims to decellularize and characterize nopal (Opuntia Ficus-indica) scaffolds, assess their degradation and the proliferation of hDPSC, and determine potential pro-inflammatory effects by assessing the expression of cyclooxygenase 1 and 2 (COX-1 and 2). The scaffolds were decellularized using a 0.5% sodium dodecyl sulfate (SDS) solution and confirmed by color, optical microscopy, and SEM. The degradation rates and mechanical properties of the scaffolds were determined by weight and solution absorbances using trypsin and PBS and tensile strength testing. Human dental pulp stem cells (hDPSCs) primary cells were used for scaffold–cell interaction and proliferation assays, as well as an MTT assay to determine proliferation. Proinflammatory protein expression of COX-I and -II was discovered by Western blot assay, and the cultures were induced into a pro-inflammatory state with interleukin 1-β. The nopal scaffolds exhibited a porous structure with an average pore size of 252 ± 77 μm. The decellularized scaffolds showed a 57% reduction in weight loss during hydrolytic degradation and a 70% reduction during enzymatic degradation. There was no difference in tensile strengths between native and decellularized scaffolds (12.5 ± 1 and 11.8 ± 0.5 MPa). Furthermore, hDPSCs showed a significant increase in cell viability of 95% and 106% at 168 h for native and decellularized scaffolds, respectively. The combination of the scaffold and hDPSCs did not cause an increase in the expression of COX-1 and COX-2 proteins. However, when the combination was exposed to IL-1β, there was an increase in the expression of COX-2. This study demonstrates the potential application of nopal scaffolds in tissue engineering and regenerative medicine or dentistry, owing to their structural characteristics, degradation properties, mechanical properties, ability to induce cell proliferation, and lack of enhancement of pro-inflammatory cytokines. Full article

Dental implants have become the leading choice for patients who lose teeth; however, dental implantation is challenged by peri-implant infections. Here, calcium-doped titanium was fabricated by the combinational use of thermal evaporation and electron beam evaporation in a vacuum; then, the material was immersed in a calcium-free phosphate-buffered saline solution containing human plasma fibrinogen and incubated at 37 °C for 1 h, creating calcium- and protein-conditioned titanium. The titanium contained 12.8 ± 1.8 at.% of calcium, which made the material more hydrophilic. Calcium release by the material during protein conditioning was able to change the conformation of the adsorbed fibrinogen, which acted against the colonization of peri-implantitis-associated pathogens (Streptococcus mutans, UA 159, and Porphyromonas gingivalis, ATCC 33277), while supporting the adhesion and growth of human gingival fibroblasts (hGFs). The present study confirms that the combination of calcium-doping and fibrinogen-conditioning is a promising pathway to meeting the clinical demand for suppressing peri-implantitis. Full article

Triply Periodic Minimal Surfaces (TPMS) are promising structures for bone tissue engineering scaffolds due to their relatively high mechanical energy absorption, smoothly interconnected porous structure, scalable unit cell topology, and relatively high surface area per volume. Calcium phosphate-based materials, such as hydroxyapatite and tricalcium phosphate, are very popular scaffold biomaterials due to their biocompatibility, bioactivity, compositional similarities to bone mineral, non-immunogenicity, and tunable biodegradation. Their brittle nature can be partially mitigated by 3D printing them in TPMS topologies such as gyroids, which are widely studied for bone regeneration, as evidenced by their presence in popular 3D-printing slicers, modeling systems, and topology optimization tools. Although structural and flow simulations have predicted promising properties of other TPMS scaffolds, such as Fischer–Koch S (FKS), to the best of our knowledge, no one has explored these possibilities for bone regeneration in the laboratory. One reason for this is that fabrication of the FKS scaffolds, such as by 3D printing, is challenged by a lack of algorithms to model and slice this topology for use by low-cost biomaterial printers. This paper presents an open-source software algorithm that we developed to create 3D-printable FKS and gyroid scaffold cubes, with a framework that can accept any continuous differentiable implicit function. We also report on our successful 3D printing of hydroxyapatite FKS scaffolds using a low-cost method that combines robocasting with layer-wise photopolymerization. Dimensional accuracy, internal microstructure, and porosity characteristics are also presented, demonstrating promising potential for the 3D printing of TPMS ceramic scaffolds for bone regeneration. Full article

Immunology research has focused on developing cancer vaccines to increase the number of tumor-specific effector cells and their ability to fight cancer over the last few decades. There is a lack of professional success in vaccines compared to checkpoint blockade and adoptive T-cell treatment. The vaccine’s inadequate delivery method and antigen selection are most likely to blame for the poor results. Antigen-specific vaccines have recently shown promising results in preclinical and early clinical investigations. To target particular cells and trigger the best immune response possible against malignancies, it is necessary to design a highly efficient and secure delivery method for cancer vaccines; however, enormous challenges must be overcome. Current research is focused on developing stimulus-responsive biomaterials, which are a subset of the range of levels of materials, to enhance therapeutic efficacy and safety and better regulate the transport and distribution of cancer immunotherapy in vivo. A concise analysis of current developments in the area of biomaterials that respond to stimuli has been provided in brief research. Current and anticipated future challenges and opportunities in the sector are also highlighted. Full article

Silver nanoparticles (AgNPs) are the most investigated antibacterial agents against multidrug resistant (MDR) pathogens. They can lead to cellular death by means of different mechanisms, damaging several cell compartments, from the external membrane, to enzymes, DNA and proteins; this simultaneous attack amplifies the toxic effect on bacteria with respect to traditional antibiotics. The effectiveness of AgNPs against MDR bacteria is strongly correlated with their chemical and morphological properties, which influence the pathways involved in cellular damage. In this review, AgNPs’ size, shape and modification by functional groups or other materials are reported, both to investigate the different synthetic pathways correlated with nanoparticles’ modifications and to evaluate the related effect on their antibacterial activity. Indeed, understanding the synthetic conditions for obtaining performing antibacterial AgNPs could help to tailor new and improved silver-based agents to combat multidrug resistance. Full article

Hydrogels exhibit excellent moldability, biodegradability, biocompatibility, and extracellular matrix-like properties, which make them widely used in biomedical fields. Because of their unique three-dimensional crosslinked hydrophilic networks, hydrogels can encapsulate various materials, such as small molecules, polymers, and particles; this has become a hot research topic in the antibacterial field. The surface modification of biomaterials by using antibacterial hydrogels as coatings contributes to the biomaterial activity and offers wide prospects for development. A variety of surface chemical strategies have been developed to bind hydrogels to the substrate surface stably. We first introduce the preparation method for antibacterial coatings in this review, which includes surface-initiated graft crosslinking polymerization, anchoring the hydrogel coating to the substrate surface, and the LbL self-assembly technique to coat crosslinked hydrogels. Then, we summarize the applications of hydrogel coating in the biomedical antibacterial field. Hydrogel itself has certain antibacterial properties, but the antibacterial effect is not sufficient. In recent research, in order to optimize its antibacterial performance, the following three antibacterial strategies are mainly adopted: bacterial repellent and inhibition, contact surface killing of bacteria, and release of antibacterial agents. We systematically introduce the antibacterial mechanism of each strategy. The review aims to provide reference for the further development and application of hydrogel coatings. Full article

The present paper aims to provide an overview of the current state-of-the-art mechanical surface modification technologies and their response in terms of surface roughness, surface texture, and microstructural change due to cold work-hardening, affecting the surface integrity and corrosion resistance of different Mg alloys. The process mechanics of five main treatment strategies, namely, shot peening, surface mechanical attrition treatment, laser shock peening, ball burnishing, and ultrasonic nanocrystal surface modification, were discussed. The influence of the process parameters on plastic deformation and degradation characteristics was thoroughly reviewed and compared from the perspectives of surface roughness, grain modification, hardness, residual stress, and corrosion resistance over short- and long-term periods. Potential and advances in new and emerging hybrid and in-situ surface treatment strategies were comprehensively eluded and summarised. This review takes a holistic approach to identifying the fundamentals, pros, and cons of each process, thereby contributing to bridging the current gap and challenge in surface modification technology for Mg alloys. To conclude, a brief summary and future outlook resulting from the discussion were presented. The findings would offer a useful insight and guide for researchers to focus on developing new surface treatment routes to resolve surface integrity and early degradation problems for successful application of biodegradable Mg alloy implants. Full article

Topographical cues on material surfaces are crucial for guiding the behavior of nerve cells and facilitating the repair of peripheral nerve defects. Previously, micron-grooved surfaces have shown great potential in controlling nerve cell alignment for studying the behavior and functions of those cells and peripheral nerve regeneration. However, the effects of smaller-sized topographical cues, such as those in the submicron- and nano-scales, on Schwann cell behavior remain poorly understood. In this study, four different submicron-grooved polystyrene films (800/400, 800/100, 400/400, and 400/100) were fabricated to study the behavior, gene expression, and membrane potential of Schwann cells. The results showed that all submicron-grooved films could guide the cell alignment and cytoskeleton in a groove depth-dependent manner. Cell proliferation and cell cycle assays revealed that there was no significant difference between the submicron groove samples and the flat control. However, the submicron grooves can direct the migration of cells and upregulate the expression of critical genes in axon regeneration and myelination (e.g., MBP and Smad6). Finally, the membrane potential of the Schwann cells was significantly altered on the grooved sample. In conclusion, this study sheds light on the role of submicron-grooved patterns in regulating the behavior and function of Schwann cells, which provides unique insights for the development of implants for peripheral nerve regeneration. Full article

Surface Pre-Reacted Glass-ionomer (S-PRG) filler, which releases strontium (Sr²⁺), borate (BO₃³⁻), fluoride (F⁻), sodium (Na⁺), silicate (SiO₃²⁻), and aluminum (Al³⁺) ions at high concentrations, is a unique glass filler that are utilized in dentistry. Because of its multiple-ion releasing characteristics, S-PRG filler exhibits several bioactivities such as tooth strengthening, acid neutralization, promotion of mineralization, inhibition of bacteria and fungi, inhibition of matrix metalloproteinases, and enhancement of cell activity. Therefore, S-PRG filler per se and S-PRG filler-containing materials have the potential to be beneficial for various dental treatments and care. Those include restorative treatment, caries prevention/management, vital pulp therapy, endodontic treatment, prevention/treatment of periodontal disease, prevention of denture stomatitis, and perforation repair/root end filling. This review summarizes bioactive functions exhibited by S-PRG filler and its possible contribution to oral health. Full article

Hydrogels are broadly employed in wound healing applications due to their high water content and tissue-mimicking mechanical properties. Healing is hindered by infection in many types of wound, including Crohn’s fistulas, tunneling wounds that form between different portions of the digestive system in Crohn’s disease patients. Owing to the rise of drug-resistant infections, alternate approaches are required to treat wound infections beyond traditional antibiotics. To address this clinical need, we designed a water-responsive shape memory polymer (SMP) hydrogel, with natural antimicrobials in the form of phenolic acids (PAs), for potential use in wound filling and healing. The shape memory properties could allow for implantation in a low-profile shape, followed by expansion and would filling, while the PAs provide localized delivery of antimicrobials. Here, we developed a urethane-crosslinked poly(vinyl alcohol) hydrogel with cinnamic (CA), p-coumaric (PCA), and caffeic (Ca-A) acid chemically or physically incorporated at varied concentrations. We examined the effects of incorporated PAs on antimicrobial, mechanical, and shape memory properties, and on cell viability. Materials with physically incorporated PAs showed improved antibacterial properties with lower biofilm formation on hydrogel surfaces. Both modulus and elongation at break could be increased simultaneously in hydrogels after both forms of PA incorporation. Cellular response in terms of initial viability and growth over time varied based on PA structure and concentration. Shape memory properties were not negatively affected by PA incorporation. These PA-containing hydrogels with antimicrobial properties could provide a new option for wound filling, infection control, and healing. Furthermore, PA content and structure provide novel tools for tuning material properties independently of network chemistry, which could be harnessed in a range of materials systems and biomedical applications. Full article

Tissue and organ regeneration are challenging issues, yet they represent the frontier of current research in the biomedical field. Currently, a major problem is the lack of ideal scaffold materials’ definition. As well known, peptide hydrogels have attracted increasing attention in recent years thanks to significant properties such as biocompatibility, biodegradability, good mechanical stability, and tissue-like elasticity. Such properties make them excellent candidates for 3D scaffold materials. In this review, the first aim is to describe the main features of a peptide hydrogel in order to be considered as a 3D scaffold, focusing in particular on mechanical properties, as well as on biodegradability and bioactivity. Then, some recent applications of peptide hydrogels in tissue engineering, including soft and hard tissues, will be discussed to analyze the most relevant research trends in this field. Full article

A push for environmentally friendly approaches to biomaterials fabrication has emerged from growing conservational concerns in recent years. Different stages in silk fibroin scaffold production, including sodium carbonate (Na₂CO₃)-based degumming and 1,1,1,3,3,3-hexafluoro-2-propanol (HFIP)-based fabrication, have drawn attention for their associated environmental concerns. Environmentally friendly alternatives have been proposed for each processing stage; however, an integrated green fibroin scaffold approach has not been characterized or used for soft tissue applications. Here, we show that the combination of sodium hydroxide (NaOH) as a substitute degumming agent with the popular “aqueous-based” alternative silk fibroin gelation method yields fibroin scaffolds with comparable properties to traditional Na₂CO₃-degummed aqueous-based scaffolds. The more environmentally friendly scaffolds were found to have comparable protein structure, morphology, compressive modulus, and degradation kinetics, with increased porosity and cell seeding density relative to traditional scaffolds. Human adipose-derived stem cells showed high viability after three days of culture while seeded in each scaffold type, with uniform cell attachment to pore walls. Adipocytes from human whole adipose tissue seeded into scaffolds were found to have similar levels of lipolytic and metabolic function between conditions, in addition to a healthy unilocular morphology. Results indicate that our more environmentally friendly methodology for silk scaffold production is a viable alternative and well suited to soft tissue applications. Full article

The formation of bacterial biofilms and the contamination of treatment water within dental unit waterlines can lead to a risk of secondary bacterial infections in immunocompromised patients. Although chemical disinfectants can reduce the contamination of treatment water, they can also cause corrosion damage to dental unit waterlines. Considering the antibacterial effect of ZnO, a ZnO-containing coating was prepared on the surface of polyurethane waterlines using polycaprolactone (PCL) with a good film-forming capacity. The ZnO-containing PCL coating improved the hydrophobicity of polyurethane waterlines, thus inhibiting the adhesion of bacteria. Moreover, the continuous slow release of Zn ions endowed polyurethane waterlines with antibacterial activity, thus effectively preventing the formation of bacterial biofilms. Meanwhile, the ZnO-containing PCL coating had good biocompatibility. The present study suggests that ZnO-containing PCL coating can realize a long-term antibacterial effect on the polyurethane waterlines by itself, providing a novel strategy for the manufacture of autonomous antibacterial dental unit waterlines. Full article

Prosthesis implantation and bone integration under bacterial infection are arduous challenges in clinical practice. It is well known that the reactive oxygen species (ROS) produced by bacterial infection around the bone defects will further hinder bone healing. To solve this problem, we prepared a ROS-scavenging hydrogel by cross-linking polyvinyl alcohol and a ROS-responsive linker, N¹-(4-boronobenzyl)-N³-(4-boronophenyl)-N¹, N¹, N³, N³-tetramethylpropane-1, 3-diaminium, to modify the microporous titanium alloy implant. The prepared hydrogel was used as an advanced ROS-scavenging tool to promote bone healing by inhibiting the ROS levels around the implant. Bifunctional hydrogel serving as a drug delivery system can release therapeutic molecules, including vancomycin, to kill bacteria and bone morphogenetic protein-2 to induce bone regeneration and integration. This multifunctional implant system that combines mechanical support and disease microenvironment targeting provides a novel strategy for bone regeneration and integration of implants in infected bone defects. Full article

The implantation of a biomaterial will lead to the immediate onset of an acute inflammatory response, which is of key importance in shaping the quality of the repair process. However, the return to homeostasis is critical to prevent a chronic inflammatory response that may impair the healing process. The resolution of the inflammatory response is now recognized as an active and highly regulated process, being described as specialized immunoresolvents that have a fundamental role in the termination of the acute inflammatory response. These mediators collectively coined as specialized pro-resolving mediators (SPMs) are a family of endogenous molecules that include lipoxins (Lx), resolvins (Rv), protectins (PD), maresins (Mar), Cysteinyl-SPMs (Cys-SPMs) and n-3 docosapentaenoic acid-derived SPMs (n-3 DPA-derived SPMs). SPMs have important anti-inflammatory and pro-resolutive actions such as decreasing the recruitment of polymorphonuclear leukocytes (PMNs), inducing the recruitment of anti-inflammatory macrophages, and increasing macrophage clearance of apoptotic cells through a process known as efferocytosis. Over the last years, the trend in biomaterials research has shifted towards the engineering of materials that are able to modulate the inflammatory response and thus stimulate appropriate immune responses, the so-called immunomodulatory biomaterials. These materials should be able to modulate the host immune response with the aim of creating a pro-regenerative microenvironment. In this review, we explore the potential of using of SPMs in the development of new immunomodulatory biomaterials and we propose insights for future research in this field. Full article

Gluten is a natural byproduct derived from wheat starch, possessing ideal biocompatibility. However, its poor mechanical properties and heterogeneous structure are not suitable for cell adhesion in biomedical applications. To resolve the issues, we prepare novel gluten (G)/sodium lauryl sulfate (SDS)/chitosan (CS) composite hydrogels by electrostatic and hydrophobic interactions. Specifically, gluten is modified by SDS to give it a negatively charged surface, and then it conjugates with positively charged chitosan to form the hydrogel. In addition, the composite formative process, surface morphology, secondary network structure, rheological property, thermal stability, and cytotoxicity are investigated. Moreover, this work demonstrates that the change can occur in surface hydrophobicity caused by the pH−eading influence of hydrogen bonds and polypeptide chains. Meanwhile, the reversible non−covalent bonding in the networks is beneficial to improving the stability of the hydrogels, which shows a prominent prospect in biomedical engineering. Full article

During corneal wound healing, corneal keratocytes are exposed to both biophysical and soluble cues that cause them to transform from a quiescent state to a repair phenotype. How keratocytes integrate these multiple cues simultaneously is not well understood. To investigate this process, primary rabbit corneal keratocytes were cultured on substrates patterned with aligned collagen fibrils and coated with adsorbed fibronectin. After 2 or 5 days of culture, keratocytes were fixed and stained to assess changes in cell morphology and markers of myofibroblastic activation by fluorescence microscopy. Initially, adsorbed fibronectin had an activating effect on the keratocytes as evidenced by changes in cell shape, stress fiber formation, and expression of alpha-smooth muscle actin (α-SMA). The magnitude of these effects depended upon substrate topography (i.e., flat substrate vs aligned collagen fibrils) and decreased with culture time. When keratocytes were simultaneously exposed to adsorbed fibronectin and soluble platelet-derived growth factor-BB (PDGF-BB), the cells elongated and had reduced expression of stress fibers and α-SMA. In the presence of PDGF-BB, keratocytes plated on the aligned collagen fibrils elongated in the direction of the fibrils. These results provide new information on how keratocytes respond to multiple simultaneous cues and how the anisotropic topography of aligned collagen fibrils influences keratocyte behavior. Full article

Cultivated meat is a fast-growing research field and an industry with great potential to overcome the limitations of traditional meat production. Cultivated meat utilizes cell culture and tissue engineering technologies to culture a vast number of cells in vitro and grow/assemble them into structures mimicking the muscle tissues of livestock animals. Stem cells with self-renewal and lineage-specific differentiation abilities have been considered one of the key cell sources for cultivated meats. However, the extensive in vitro culturing/expansion of stem cells results in a reduction in their abilities to proliferate and differentiate. Extracellular matrix (ECM) has been used as a culturing substrate to support cell expansion for cell-based therapies in regenerative medicine due to its resemblance to the native microenvironment of cells. In this study, the effect of the ECM on the expansion of bovine umbilical cord stromal cells (BUSC) in vitro was evaluated and characterized. BUSCs with multi-lineage differentiation potentials were isolated from bovine placental tissue. Decellularized ECM prepared from a confluent monolayer of bovine fibroblasts (BF) is free of cellular components but contains major ECM proteins such as fibronectin and type I collagen and ECM-associated growth factors. Expansion of BUSC on ECM for three passages (around three weeks) resulted in about 500-fold amplification, while cells were amplified less than 10-fold when cultured on standard tissue culture plates (TCP). Moreover, the presence of ECM reduced the requirement for serum in the culture medium. Importantly, the cells amplified on ECM retained their differentiation abilities better than cells cultured on TCP. The results of our study support the notion that monolayer cell-derived ECM may be a strategy to expand bovine cells in vitro effectively and efficiently. Full article

Bone has a special structure that is both stiff and elastic, and the composition of bone confers it with an exceptional mechanical property. However, bone substitute materials that are made of the same hydroxyapatite (HA) and collagen do not offer the same mechanical properties. It is important for bionic bone preparation to understand the structure of bone and the mineralization process and factors. In this paper, the research on the mineralization of collagen is reviewed in terms of the mechanical properties in recent years. Firstly, the structure and mechanical properties of bone are analyzed, and the differences of bone in different parts are described. Then, different scaffolds for bone repair are suggested considering bone repair sites. Mineralized collagen seems to be a better option for new composite scaffolds. Last, the paper introduces the most common method to prepare mineralized collagen and summarizes the factors influencing collagen mineralization and methods to analyze its mechanical properties. In conclusion, mineralized collagen is thought to be an ideal bone substitute material because it promotes faster development. Among the factors that promote collagen mineralization, more attention should be given to the mechanical loading factors of bone. Full article

Polydimethylsiloxane (PDMS) has been widely used to make lab-on-a-chip devices, such as reactors and sensors, for biological research. Real-time nucleic acid testing is one of the main applications of PDMS microfluidic chips due to their high biocompatibility and transparency. However, the inherent hydrophobicity and excessive gas permeability of PDMS hinder its applications in many fields. This study developed a silicon-based polydimethylsiloxane-polyethylene-glycol (PDMS-PEG) copolymer microfluidic chip, the PDMS-PEG copolymer silicon chip (PPc-Si chip), for biomolecular diagnosis. By adjusting the modifier formula for PDMS, the hydrophilic switch occurred within 15 s after contact with water, resulting in only a 0.8% reduction in transmittance after modification. In addition, we evaluated the transmittance at a wide range of wavelengths from 200 nm to 1000 nm to provide a reference for its optical property study and application in optical-related devices. The improved hydrophilicity was achieved by introducing a large number of hydroxyl groups, which also resulted in excellent bonding strength of PPc-Si chips. The bonding condition was easy to achieve and time-saving. Real-time PCR tests were successfully conducted with higher efficiency and lower non-specific absorption. This chip has a high potential for a wide range of applications in point-of-care tests (POCT) and rapid disease diagnosis. Full article

The development of nanosystems, which can photooxygenate amyloid-β (Aβ), detect the Tau protein, and inhibit effectively the Tau aggregation, is increasingly important in the diagnosis and therapy of Alzheimer’s disease (AD). Herein, UCNPs-LMB/VQIVYK (UCNPs: upconversion nanoparticles, LMB: Leucomethylene blue, and VQIVYK: Biocompatible peptide) is designed as a HOCl-controlled released nanosystem for AD synergistic treatment. Under exposure to high levels of HOCl, the released MB from UCNPs-LMB/VQIVYK will produce singlet oxygen (¹O₂) under red light to depolymerize Aβ aggregation and reduce cytotoxicity. Meanwhile, UCNPs-LMB/VQIVYK can act as an inhibitor to decrease Tau-induced neurotoxicity. Besides, UCNPs-LMB/VQIVYK can be used for upconversion luminescence (UCL) due to its unexceptionable luminescence properties. This HOCl-responsive nanosystem offers a new therapy for AD treatment. Full article

The solid phase of a commercial calcium phosphate (Graftys^® HBS) was combined with ovine or human blood stabilized either with sodium citrate or sodium heparin. The presence of blood delayed the setting reaction of the cement by ca. 7–15 h, depending on the nature of the blood and blood stabilizer. This phenomenon was found to be directly related to the particle size of the HBS solid phase, since prolonged grinding of the latter resulted in a shortened setting time (10–30 min). Even though ca. 10 h were necessary for the HBS blood composite to harden, its cohesion right after injection was improved when compared to the HBS reference as well as its injectability. A fibrin-based material was gradually formed in the HBS blood composite to end-up, after ca. 100 h, with a dense 3D organic network present in the intergranular space, thus affecting the microstructure of the composite. Indeed, SEM analyses of polished cross-sections showed areas of low mineral density (over 10–20 µm) spread in the whole volume of the HBS blood composite. Most importantly, when the two cement formulations were injected in the tibial subchondral cancellous bone in a bone marrow lesion ovine model, quantitative SEM analyses showed a highly significant difference between the HBS reference versus its analogue combined with blood. After a 4-month implantation, histological analyses clearly showed that the HBS blood composite underwent high resorption (remaining cement: ca. 13.1 ± 7.3%) and new bone formation (newly formed bone: 41.8 ± 14.7%). This was in sharp contrast with the case of the HBS reference for which a low resorption rate was observed (remaining cement: 79.0 ± 6.9%; newly formed bone: 8.6 ± 4.8%). This study suggested that the particular microstructure, induced by the use of blood as the HBS liquid phase, favored quicker colonization of the implant and acceleration of its replacement by newly formed bone. For this reason, the HBS blood composite might be worth considering as a potentially suitable material for subchondroplasty. Full article

Mesenchymal stem cells (MSCs) have recently been widely used to treat osteoarthritis (OA). Our prior research shows that tropoelastin (TE) increases MSC activity and protects knee cartilage from OA-related degradation. The underlying mechanism might be that TE regulates the paracrine of MSCs. Exosomes (Exos), the paracrine secretion of MSCs, have been found to protect chondrocytes, reduce inflammation, and preserve the cartilage matrix. In this study, we used Exos derived from TE-pretreated adipose-derived stem cells (ADSCs) (TE-Exo^ADSCs) as an injection medium, and compared it with Exos derived from unpretreated ADSCs (Exo^ADSCs). We found that TE-Exo^ADSCs could effectively enhance the matrix synthesis of chondrocytes in vitro. Moreover, TE pretreatment increased the ability of ADSCs to secrete Exos. In addition, compared with Exo^ADSCs, TE-Exo^ADSCs exhibited therapeutic effects in the anterior cruciate ligament transection (ACLT)-induced OA model. Further, we observed that TE altered the microRNA expression in Exo^ADSCs and identified one differentially upregulated microRNA: miR-451-5p. In conclusion, TE-Exo^ADSCs helped maintain the chondrocyte phenotype in vitro, and promoted cartilage repair in vivo. These therapeutic effects might be related with the altered expression of miR-451-5p in the Exo^ADSCs. Thus, the intra-articular delivery of Exos derived from ADSCs with TE pretreatment could be a new approach to treat OA. Full article

Herein, improving the antibacterial activity of a hydrogel system of sodium alginate (SA) and basic chitosan (CS) using sodium hydrogen carbonate by adding AgNPs was investigated. SA-coated AgNPs produced by ascorbic acid or microwave heating were evaluated for their antimicrobial activity. Unlike ascorbic acid, the microwave-assisted method produced uniform and stable SA-AgNPs with an optimal reaction time of 8 min. Transmission electron microscopy (TEM) confirmed the formation of SA-AgNPs with an average particle size of 9 ± 2 nm. Moreover, UV-vis spectroscopy confirmed the optimal conditions for SA-AgNP synthesis (0.5% SA, 50 mM AgNO₃, and pH 9 at 80 °C). Fourier transform infrared (FTIR) spectroscopy confirmed that the –COO⁻ group of SA electrostatically interacted with either the Ag⁺ or –NH₃⁺ of CS. Adding glucono-δ-lactone (GDL) to the mixture of SA-AgNPs/CS resulted in a low pH (below the pKa of CS). An SA-AgNPs/CS gel was formed successfully and retained its shape. This hydrogel exhibited 25 ± 2 mm and 21 ± 1 mm inhibition zones against E. coli and B. subtilis and showed low cytotoxicity. Additionally, the SA-AgNP/CS gel showed higher mechanical strength than SA/CS gels, possibly due to the higher crosslink density. In this work, a novel antibacterial hydrogel system was synthesized via 8 min of microwave heating. Full article

Lutein, a photo- and thermo-labile macular pigment, prevents the retina from suffering ocular inflammation with its antioxidant and anti-inflammatory activity. However, its biological activity is poor due to poor solubility and bioavailability. Therefore, we developed a PLGA NCs (+PL), (poly (lactic-co-glycolic acid) nanocarrier with phospholipid) to improve the biological availability and bioefficacy of lutein in the retina of lipopolysaccharide (LPS)-induced lutein-devoid (LD) mice. The effect of lutein-loaded NCs with/without PL was studied in comparison with micellar lutein. The induction of inflammation by LPS significantly increased the production of nitrites in the LPS-induced group, revealing higher levels of nitric oxide (NO) in the serum (760%) and retina (891%) compared to the control group. Malondialdehyde (MDA) levels in the serum (93%) and retina (205%) of the LPS-induced group were higher compared to the control group. LPS induction resulted in increased protein carbonyls in the serum (481%) and retina (487%) of the LPS group compared to the control group. Further, to conclude, lutein-PLGA NCs (+PL) effectively down-regulated inflammatory complications in the retina. Full article

Tracheal stenosis and defects occur congenitally and in patients who have undergone tracheal intubation and tracheostomy due to long-term intensive care. Such issues may also be observed during tracheal removal during malignant head and neck tumor resection. However, to date, no treatment method has been identified that can simultaneously restore the appearance of the tracheal skeleton while maintaining respiratory function in patients with tracheal defects. Therefore, there is an urgent need to develop a method that can maintain tracheal function while simultaneously reconstructing the skeletal structure of the trachea. Under such circumstances, the advent of additive manufacturing technology that can create customized structures using patient medical image data provides new possibilities for tracheal reconstruction surgery. In this study, the three-dimensional (3D) printing and bioprinting technologies used in tracheal reconstruction are summarized, and various research results related to the reconstruction of mucous membranes, cartilage, blood vessels, and muscle tissue, which are tissues required for tracheal reconstruction, are classified. The prospects for 3D-printed tracheas in clinical studies are also described. This review serves as a guide for the development of artificial tracheas and clinical trials using 3D printing and bioprinting. Full article

Nitinol (NiTi), an alloy of nickel and titanium, wires are an important biomedical material that has been used in catheter tubes, guidewires, stents, and other surgical instruments. As such wires are temporarily or permanently inserted inside the human body, their surfaces need to be smoothed and cleaned in order to prevent wear, friction, and adhesion of bacteria. In this study, NiTi wire samples of micro-scale diameters (i.e., Ø 200 μm and Ø 400 μm) were polished by an advanced magnetic abrasive finishing (MAF) process using a nanoscale polishing method. Furthermore, bacterial adhesion (i.e., Escherichia coli (E. coli), and Staphylococcus aureus (S. aureus)) to the initial and final surfaces of NiTi wires were investigated and compared in order to assess the impact of surface roughness on bacterial adhesion to the surfaces of NiTi wires. The finding revealed that the surfaces of NiTi wires were clean and smooth with a lack of particle impurities and toxic components on the final surface polished using the advanced MAF process. The surface roughness Ra values of the Ø 200 μm and Ø 400 μm NiTi wires were smoothly enhanced to 20 nm and 30 nm from the 140 nm and 280 nm initial surface roughness values. Importantly, polishing the surfaces of a biomedical material such as NiTi wire to nano-level roughness can significantly reduce bacterial adhesion on the surface by more than 83.48% in the case of S. aureus, while in the case of E. coli was more than 70.67%. Full article

This study aimed to use an in-air micro-particle-induced X-ray/gamma emission (in-air µPIXE/PIGE) system to evaluate tooth-bound fluoride (T-F) in dentin following the application of fluoride-containing tooth-coating materials. Three fluoride-containing coating materials (PRG Barrier Coat, Clinpro XT varnish, and Fuji IX EXTRA) and a control were applied to the root dentin surface of human molars (n = 6, total 48 samples). Samples were stored in a remineralizing solution (pH 7.0) for 7 or 28 days and then sectioned into two adjacent slices. One slice of each sample was immersed in 1M potassium hydroxide (KOH) solution for 24 h and rinsed with water for 5 min for the T-F analysis. The other slice did not undergo KOH treatment and was used to analyze the total fluoride content (W-F). The fluoride and calcium distributions were measured in all the slices using an in-air µPIXE/PIGE. Additionally, the amount of fluoride released from each material was measured. Clinpro XT varnish demonstrated the highest fluoride release among all the materials and tended to show high W-F and T-F and lower T-F/W-F ratios. Our study demonstrates that a high fluoride-releasing material shows high fluoride distribution into the tooth structure and low conversion from fluoride uptake by tooth-bound fluoride. Full article

Acridine and its derivatives (9-chloroacridine and 9-aminoacridine) are investigated here, supported on FAU type zeolite Y, as a delivery system of anticancer agents. FTIR/Raman spectroscopy and electron microscopy revealed successful drug loading on the zeolite surface, while spectrofluorimetry was employed for drug quantification. The effects of the tested compounds on cell viability were evaluated using in vitro methylthiazol-tetrazolium (MTT) colorimetric technique against human colorectal carcinoma (cell line HCT-116) and MRC-5 fibroblasts. Zeolite structure remained unchanged during homogeneous drug impregnation with achieved drug loadings in the 18–21 mg/g range. The highest drug release, in the µM concentration range, with favourable kinetics was established for zeolite-supported 9-aminoacridine. The acridine delivery via zeolite carrier is viewed in terms of solvation energy and zeolite adsorption sites. The cytotoxic effect of supported acridines on HCT-116 cells reveals that the zeolite carrier improves toxicity, while the highest efficiency is displayed by zeolite-impregnated 9-aminoacridine. The 9-aminoacridine delivery via zeolite carrier favours healthy tissue preservation while accompanying increased toxicity toward cancer cells. Cytotoxicity results are well correlated with theoretical modelling and release study, providing promising results for applicative purposes. Full article

The aim of the work was to examine the possibility of using modified halloysite nanotubes as a gentamicin carrier and to determine the usefulness of the modification in terms of the effect on the amount of the drug attached, its release time, but also on the biocidal properties of the carriers. In order to fully examine the halloysite in terms of the possibility of gentamicin incorporating, a number of modifications of the native halloysite were carried out prior to gentamicin intercalation with the use of sodium alkali, sulfuric and phosphoric acids, curcumin and the process of delamination of nanotubes (expanded halloysite) with ammonium persulfate in sulfuric acid. Gentamicin was added to unmodified and modified halloysite in an amount corresponding to the cation exchange capacity of pure halloysite from the Polish Dunino deposit, which was the reference sample for all modified carriers. The obtained materials were tested to determine the effect of surface modification and their interaction with the introduced antibiotic on the biological activity of the carrier, kinetics of drug release, as well as on the antibacterial activity against Escherichia coli Gram-negative bacteria (reference strain). For all materials, structural changes were examined using infrared spectroscopy (FTIR) and X-ray diffraction (XRD); thermal differential scanning calorimetry with thermogravimetric analysis (DSC/TG) was performed as well. The samples were also observed for morphological changes after modification and drug activation by transmission electron microscopy (TEM). The conducted tests clearly show that all samples of halloysite intercalated with gentamicin showed high antibacterial activity, with the highest antibacterial activity for the sample modified with sodium hydroxide and intercalated with the drug. It was found that the type of halloysite surface modification has a significant effect on the amount of gentamicin intercalated and then released into the surrounding environment but does not significantly affect its ability to further influence drug release over time. The highest amount of drug released among all intercalated samples was recorded for halloysite modified with ammonium persulfate (real loading efficiency above 11%), for which high antibacterial activity was found after surface modification, before drug intercalation. It is also worth noting that intrinsic antibacterial activity was found for non-drug-intercalated materials after surface functionalization with phosphoric acid (V) and ammonium persulfate in the presence of sulfuric acid (V). Full article

Hydrogels have emerged as important soft materials with numerous applications in fields including biomedicine, biomimetic smart materials, and electrochemistry. Because of their outstanding photo-physical properties and prolonged colloidal stability, the serendipitous findings of carbon quantum dots (CQDs) have introduced a new topic of investigation for materials scientists. CQDs confined polymeric hydrogel nanocomposites have emerged as novel materials with integrated properties of the individual constituents, resulting in vital uses in the realm of soft nanomaterials. Immobilizing CQDs within hydrogels has been shown to be a smart tactic for preventing the aggregation-caused quenching effect and also for manipulating the characteristics of hydrogels and introducing new properties. The combination of these two very different types of materials results in not only structural diversity but also significant improvements in many property aspects, leading to novel multifunctional materials. This review covers the synthesis of doped CQDs, different fabrication techniques for nanostructured materials made of CQDs and polymers, as well as their applications in sustained drug delivery. Finally, a brief overview of the present market and future perspectives are discussed. Full article