Search Results (134)

In response to the growing demand for sustainable biomaterials in tissue engineering, we investigated the potential of structurally intact brown seaweed scaffolds derived from Laminaria digitata (L.D.) and Laminaria saccharina (L.S.), produced by a detergent-free, visible-light decellularization process aimed at preserving structural integrity. Blades were submerged in cold flow-through and aerated water with red (620 nm) and blue (470 nm) light exposure for 4 weeks. Histology, scanning electron microscopy (SEM), and micro-computed tomography (micro-CT) analyses demonstrated that the light decellularization process removed cells/debris, maintained essential structural features, and significantly increased scaffold porosity. Mechanical property analysis through tensile testing revealed a substantial increase in tensile strength post decellularization, with L.D. scaffolds increasing from 3.4 MPa to 8.7 MPa and L.S. scaffolds from 2.1 MPa to 6.6 MPa. Chemical analysis indicated notable alterations in polysaccharide and protein composition following decellularization. Additionally, scaffolds retained high swelling and fluid absorption capacities, critical for biomedical uses. These findings underscore that the decellularized L.D. and L.S. scaffolds preserved structural integrity and exhibited enhanced mechanical properties, interconnected porous structures, and significant liquid retention capabilities, establishing them as promising biomaterial candidates for soft-tissue reinforcement, wound care, and broader applications in regenerative medicine. Full article

Healing large bone defects remains challenging. Gelatin scaffolds are biocompatible and biodegradable, but lack osteoinductive activity. Plant-derived exosomes carry miRNAs, growth factors, and proteins that modulate osteogenesis, but free exosomes suffer from poor stability, limited targeting, and low bioavailability in vivo. We developed a 3D GelMA hydrogel loaded with Epimedium-derived exosomes (“GelMA@Exo”) to improve exosome retention, stability, and sustained release. Its effects on MC3T3-E1 preosteoblasts—including proliferation, osteogenic differentiation, migration, and senescence—were evaluated via in vitro assays. Angiogenic potential was assessed using HUVECs. Underlying mechanisms were examined at transcriptomic and protein levels to elucidate GelMA@Exo’s therapeutic osteogenesis actions. GelMA@Exo exhibited sustained exosome release, enhancing exosome retention and cellular uptake. In vitro, GelMA@Exo markedly boosted MC3T3-E1 proliferation, migration, and mineralized nodule formation, while reducing senescence markers and promoting angiogenesis in HUVECs. Mechanistically, GelMA@Exo upregulated key osteogenic markers (RUNX2, TGF-β1, Osterix, COL1A1, ALPL) and activated the PI3K/Akt pathway. Transcriptomic data confirmed global upregulation of osteogenesis-related genes and bone-regeneration pathways. This study presents a GelMA hydrogel functionalized with plant-derived exosomes, which synergistically provides osteoinductive stimuli and structural support. The GelMA@Exo platform offers a versatile strategy for localized delivery of natural bioactive molecules and a promising approach for bone tissue engineering. Our findings provide strong experimental evidence for the translational potential of plant-derived exosomes in regenerative medicine. Full article

Extracellular vesicles (EVs) have emerged as promising acellular tools for modulating immune responses for tissue engineering applications. This study explores the potential of human fibroblast-derived EVs delivered within a three-dimensional (3D) injectable scaffold composed of polycaprolactone (PCL) nanofibers and collagen (PNCOL) to reprogram macrophage behavior and support scaffold integrity under inflammatory conditions. EVs were successfully isolated from human fibroblasts using ultracentrifugation and characterized for purity, size distribution and surface markers (CD63 and CD9). Macrophage-laden PNCOL scaffolds were prepared under three conditions: macrophage-only (MP), fibroblast co-encapsulated (F-MP), and EV-encapsulated (EV-MP) groups. Structural integrity was assessed via scanning electron microscopy and Masson’s trichrome staining, while immunomodulatory effects were evaluated through metabolic assays, gene expression profiling, and immunohistochemistry for macrophage polarization markers (CD80, CD206). When co-encapsulated with pro-inflammatory (M1) macrophages in PNCOL scaffolds, fibroblast-derived EVs preserved scaffold structure and significantly enhanced macrophage metabolic activity compared to the control (MP) and other experimental group (F-MP). The gene expression and immunohistochemistry data demonstrated substantial upregulation of anti-inflammatory markers (TGF-β, CD163, and CCL18) and surface protein CD206, indicating a phenotypic shift toward M2-like macrophages for EV-encapsulated scaffolds relative to the other groups. The findings of this study demonstrate that fibroblast-derived EVs integrated into injectable PCL–collagen scaffolds offer a viable, cell-free approach to modulate inflammation, preserve scaffold structure, and support regenerative healing. This strategy holds significant promise for advancing immuno-instructive platforms in regenerative medicine, particularly in settings where conventional cell therapies face limitations in survival, cost, or safety. Full article

The cryopreservation of three-dimensional (3D) biofabricated constructs is a key enabler for their clinical application in regenerative medicine. Unlike two-dimensional (2D) cultures, 3D systems such as encapsulated cell spheroids, molded hydrogels, and bioprinted tissues present specific challenges related to cryoprotectant (CPA) diffusion, thermal gradients, and ice formation during freezing and thawing. This review examines the current strategies for preserving 3D constructs, focusing on the role of biomaterials as cryoprotective matrices. Natural polymers (e.g., hyaluronic acid, alginate, chitosan), protein-based scaffolds (e.g., silk fibroin, sericin), and synthetic polymers (e.g., polyethylene glycol (PEG), polyvinyl alcohol (PVA)) are evaluated for their ability to support cell viability, structural integrity, and CPA transport. Special attention is given to cryoprotectant systems that are free of dimethyl sulfoxide (DMSO), and to the influence of hydrogel architecture on freezing outcomes. We have compared the efficacy and limitations of slow freezing and vitrification protocols and review innovative approaches such as temperature-controlled cryoprinting, nano-warming, and hybrid scaffolds with improved cryocompatibility. Additionally, we address the regulatory and manufacturing challenges associated with developing Good Manufacturing Practice (GMP)-compliant cryopreservation workflows. Overall, this review provides an integrated perspective on material-based strategies for 3D cryopreservation and identifies future directions to enable the long-term storage and clinical translation of engineered tissues. Full article

Tracheal reconstruction remains a formidable clinical challenge, particularly for long-segment defects that are not amenable to standard surgical resection or primary anastomosis. Tissue engineering has emerged as a promising strategy for restoring the tracheal structure and function through the integration of biomaterials, stem cells, and bioactive molecules. This review provides a comprehensive overview of recent advances in tissue-engineered tracheal grafts, particularly in scaffold design, cellular sources, fabrication technologies, and early clinical experience. Innovations in biomaterial science, three-dimensional printing, and scaffold-free fabrication approaches have broadened the prospects for patient-specific airway reconstruction. However, persistent challenges, including incomplete epithelial regeneration and mechanical instability, have hindered its clinical translation. Future efforts should focus on the design of modular biomimetic scaffolds, the enhancement of immunomodulatory strategies, and preclinical validation using robust large animal models. Sustained interdisciplinary collaboration among surgical, engineering, and biological fields is crucial for advancing tissue-engineered tracheal grafts for routine clinical applications. Within this context, biomimetic approaches, including three-dimensional bioprinting, hybrid materials, and scaffold-free constructs, are gaining prominence as strategies to replicate the trachea’s native architecture and improve graft integration. Full article

Articular cartilage is an avascular and aneural connective tissue that is frequently damaged due to trauma or degenerative joint diseases, often resulting in arthritis. Its limited intrinsic capacity for self-renewal poses a significant challenge to effective repair. Hence, the development of regenerative strategies is essential to enhance the poor intrinsic healing of cartilage tissue. Photobiomodulation (PBM) has gained increasing attention as a noninvasive, drug-free, and safe approach. PBM exerts photobiological effects that promote cellular responses and reduce inflammatory conditions, all of which are beneficial for cartilage repair. Nonetheless, the efficacy of PBM varies depending on treatment parameters and treated targets. This review first summarizes PBM parameter-dependent outcomes in cartilage regeneration studies. Reported data indicate frequent use of red lasers (600–660 nm, 0–10 J/cm²), GaAIAs lasers (800–880 nm, 10–50 J/cm²), and Nd:YAG lasers (1064 nm, up to 200 J/cm²) in in vitro, in vivo, and clinical studies. Moreover, PBM in conjunction with cartilage tissue engineering (CTE) has shown synergistic effects, enhancing scaffold-based repair outcomes. This review additionally explores PBM applications within CTE frameworks. The summarized findings aim to inform researchers and physicians by outlining optimized PBM strategies and highlighting PBM’s strong potential in promoting cartilage regeneration, both independently and in combination with CTE. Full article

Background/Objectives: Polymeric monoaxial nanofibers are gaining prominence due to their numerous applications, particularly in functional scenarios such as wound management. The study successfully developed and built a special-purpose vessel and device for fabricating polymeric nanofibers. Fabrication of composite scaffolds from piezoelectric poly(vinylidenefluoride-trifluoroethylene) copolymer (PVDF-TrFE) nanofibers encapsulated with myrrh extract was investigated. Methods: The gyrospun nanofibers were characterized using SEM, EDX, FTIR, XRD, and TGA to assess the properties of the composite materials. The study also investigated the release profile of myrrh extract from the nanofibers, demonstrating its potential for sustained drug delivery. The composite’s antimicrobial properties were evaluated using the disc diffusion method against various pathogenic microbes, showcasing their effectiveness. Results: It was found that an 18% (w/v) PVDF-TrFE concentration produces the best fiber mats compared to 20% and 25%, resulting in an average fiber diameter of 411 nm. Myrrh extract was added in varying amounts (10%, 15%, and 20%), with the best average fiber diameter identified at 10%, measuring 436 nm. The results indicated that the composite nanofibers were uniform, bead-free, and aligned without myrrh. The study observed a cumulative release of 79.66% myrrh over 72 h. The release profile showed an initial burst release of 46.85% within the first six hours, followed by a sustained release phase. Encapsulation efficiency was 89.8%, with a drug loading efficiency of 30%. Antibacterial activity peaked at 20% myrrh extract. S. mutans was the most sensitive pathogen to myrrh extract. Conclusions: Due to the piezoelectric effect of PVDF-TrFE and the significant antibacterial activity of myrrh, the prepared biohybrid nanofibers will open new avenues toward tissue engineering and wound healing applications. Full article

Conventionally, root canal treatment is performed when the dental pulp is severely damaged or lost due to dental trauma or bacterial endodontic infections. This treatment involves removing the compromised or infected pulp tissue, disinfecting the root canal system, and sealing it with inert, non-degradable materials. However, contemporary endodontic treatment has shifted from merely obturating the root canal system with inert materials to guiding endodontic tissue regeneration through biological approaches. The ultimate goal of regenerative endodontics is to restore dental pulp tissue with structural organization and functional characteristics akin to the native pulp, leveraging advancements in tissue engineering and biomaterial sciences. Dental pulp tissue engineering commonly employs scaffold-based strategies, utilizing biomaterials as initial platforms for cell and growth factor delivery, which subsequently act as scaffolds for cell proliferation, differentiation and maturation. However, cells possess an intrinsic capacity for self-organization into spheroids and can generate their own extracellular matrix, eliminating the need for external scaffolds. This self-assembling property presents a promising alternative for scaffold-free dental pulp engineering, addressing limitations associated with biomaterial-based approaches. This review provides a comprehensive overview of cell-based, self-assembling and scaffold-free approaches in dental pulp tissue engineering, highlighting their potential advantages and challenges in advancing regenerative endodontics. Full article

Guided tissue regeneration (GTR) membranes are pivotal in regenerative medicine. While their effectiveness is established in general populations, their application in immunocompromised patients, such as those with diabetes or cancer, remains underexplored. This review evaluated evidence on GTR membranes in immunocompromised settings, focusing on their mechanisms, outcomes, and challenges posed by systemic conditions. A systematic search identified studies on GTR use in these populations. Inclusion criteria were peer-reviewed articles in English on human samples or relevant preclinical models. Of 218 articles, 5 met the criteria. These highlighted advancements in GTR technologies, such as stem cell integration, growth factor-enriched scaffolds, and scaffold-free tissue engineering. Stem cell-based approaches improved regeneration, especially with biomimetic designs incorporating bone morphogenetic protein-2. Innovations like microcavity-rich scaffolds enhanced angiogenesis and osteogenesis, while scaffold-free constructs minimized immunogenicity and supported functional tissue regeneration. Preclinical models demonstrated GTR membranes’ potential for addressing large-scale tissue deficits in compromised environments. GTR membranes show promise for immunocompromised patients, but further research is needed to validate their clinical efficacy, address patient-specific challenges, and evaluate long-term outcomes. These technologies could transform regenerative medicine, providing sustainable solutions for high-risk populations. Full article

Antimicrobial resistance is one of the drastically increasing major global health threats due to the misuse and overuse of antibiotics as traditional antimicrobial agents, which render urgent the need for alternative and safer antimicrobial agents, such as essential oils (EOs). Although the strong antimicrobial activity of various EOs has already been studied and revealed, their characteristic high sensitivity and volatility drives the need towards a more efficient drug administration method via a biomaterial system. Herein, the potential of Thymus sibthorpii EO incorporated in functionalized antibacterial collagen hydrogels was investigated. At first, the optimally stabilized type I collagen hydrogels via six different multi-arm poly (ethylene glycol) succinimidyl glutarate (starPEG) crosslinkers were determined by assessing the free amine content and the resistance to enzymatic degradation. Subsequently, 0.5, 1, and 2% v/v of EO were incorporated into optimized collagen hydrogels, and the release profile, as well as release kinetics, were studied. Finally, biomaterial cytocompatibility tests were performed. Thymus sibthorpii EO was released from the hydrogel matrix via Fickian diffusion and showed sustained release and 0.5% v/v EO-loaded hydrogels showed adequate antibacterial activity against Staphylococcus aureus and did not show any statistically significant difference compared to penicillin (p < 0.05). Moreover, none of the fabricated composite antibacterial scaffolds displayed any cytotoxicity on NIH-3T3 fibroblasts. In conclusion, this work presents an innovative antibacterial biomaterial system for tissue engineering applications, which could serve as a promising alternative to antibiotics, contributing to coping with the issue of antimicrobial resistance. Full article

Background/Objectives: Cartilage injuries and osteoarthritis are prevalent public health problems, due to their disabling nature and economic impact. Mesenchymal stromal cells (MSCs) isolated from different tissues have the immunomodulatory capacity to regulate local joint environment. This translational study aims to compare cartilage restoration from MSCs from the synovial membrane (SM) and dental pulp (DP) by a tissue-engineered construct with Good Manufacturing Practices. Methods: A controlled experimental study was conducted on fourteen miniature pigs, using scaffold-free Tissue Engineering Constructs (TECs) from DP and SM MSCs, with a 6-month follow-up. Total thickness cartilage defects were created in both hind knees; one side was left untreated and the other received a TEC from either DP (n = 7) or SM (n = 7). An MRI assessed the morphology using the MOCART scoring system, T2 mapping evaluated water, and collagen fiber composition, and histological analysis was performed using the ICRS-2 score. Results: The untreated group had a mean MOCART value of 46.2 ± 13.4, while the SM-treated group was 65.7 ± 15.5 (p < 0.05) and the DP-treated group was 59.0 ± 7.9 (n.s.). The T2 mapping indicated a mean value of T2 of 54.9 ± 1.9 for native cartilage, with the untreated group at 50.9 ± 2.4 (p < 0.05). No difference was found between the T2 value of native cartilage and the treated groups. The ICRS-2 mean values were 42.1 ± 14.8 for the untreated group, 64.3 ± 19.0 for SM (p < 0.05), and 54.3 ± 12.2 for DP (n.s.). Conclusion: MRI and histological analysis indicated that TEC treatment led to superior cartilage coverage and quality compared to the defect group. TECs from SM demonstrated better results than the defect group in the histological assessment. Full article

Recent advances in regenerative medicine provide encouraging strategies to produce artificial skin substitutes. Gelatin scaffolds are successfully used as wound-dressing materials due to their superior properties, such as biocompatibility and the ability to mimic the extracellular matrix of the surrounding environment. In this study, five gelatin combination solutions were prepared and successfully electrospun using an electrospinning technique. After careful screening, the optimal concentration of the most promising combination was selected for further investigation. The obtained scaffolds were crosslinked with 25% glutaraldehyde vapor and characterized by scanning electron microscopy, energy-dispersive X-ray spectroscopy, and Fourier-transform infrared spectroscopy. The incorporation of antibiotic agents such as ciprofloxacin hydrochloride and gentamicin sulfate into gelatin membranes improved the already existing antibacterial properties of antibiotic-free gelatin scaffolds against Pseudomonas aeruginosa and Staphylococcus aureus. Also, the outcomes from the in vivo model study revealed that skin regeneration was significantly accelerated with gelatin/ciprofloxacin scaffold treatment. Moreover, the gelatin nanofibers were found to strongly promote the neoangiogenic process in the in vivo chick embryo chorioallantoic membrane assay. Finally, the combination of gelatin’s extracellular matrix and antibacterial agents in the scaffold suggests its potential for effective wound-healing treatments, emphasizing the importance of gelatin scaffolds in tissue engineering. Full article

Fabrication of scaffolds via 3D printing is a promising approach for tissue engineering. In this study, we combined 3D printing with cryogenic crosslinking to create biocompatible gelatin/oxidized alginate (Gel/OxAlg) scaffolds with large pore sizes, beneficial for bone tissue regeneration. To enhance the osteogenic effects and mechanical properties of these scaffolds, we evaluated the impact of hydroxyapatite (HAp) on the rheological characteristics of the 2.86% (1:1) Gel/OxAlg ink. We investigated the morphological and mechanical properties of scaffolds with low, 5%, and high 10% HAp content, as well as the resulting bio- and osteogenic effects. Scanning electron microscopy revealed a reduction in pore sizes from 160 to 180 µm (HAp-free) and from 120 to 140 µm for both HAp-containing scaffolds. Increased stability and higher Young’s moduli were measured for 5% and 10% HAp (18 and 21 kPa, respectively) compared to 11 kPa for HAp-free constructs. Biological assessments with mesenchymal stem cells indicated excellent cytocompatibility and osteogenic differentiation in all scaffolds, with high degree of mineralization in HAp-containing constructs. Scaffolds with 5% HAp exhibited improved mechanical characteristics and shape fidelity, demonstrated positive osteogenic impact, and enhanced bone tissue formation. Increasing the HAp content to 10% did not show any advantages in osteogenesis, offering a minor increase in mechanical strength at the cost of significantly compromised shape fidelity. Full article

Mesenchymal stem cells (MSCs) have emerged as a promising approach for drug delivery strategies because of their unique properties. These strategies include stem cell membrane-coated nanoparticles, stem cell-derived extracellular vesicles, immunomodulatory effects, stem cell-laden scaffolds, and scaffold-free stem cell sheets. MSCs offer advantages such as low immunogenicity, homing ability, and tumor tropism, making them ideal for targeted drug delivery systems. Stem cell-derived extracellular vesicles have gained attention for their immune properties and tumor-homing abilities, presenting a potential solution for drug delivery challenges. The relationship between MSC-based drug delivery and the self-renewal and differentiation capabilities of MSCs lies in the potential of engineered MSCs to serve as effective carriers for therapeutic agents while maintaining their intrinsic properties. MSCs exhibit potent immunosuppressive functions in MSC-based drug delivery strategies. Stem cell-derived EVs have low immunogenicity and strong therapeutic potential for tissue repair and regeneration. Scaffold-free stem cell sheets represent a cutting-edge approach in regenerative medicine, offering a versatile platform for tissue engineering and regeneration across different medical specialties. MSCs have shown great potential for clinical applications in regenerative medicine because of their ability to differentiate into various cell types, secrete bioactive factors, and modulate immune responses. Researchers are exploring these innovative approaches to enhance drug delivery efficiency and effectiveness in treating various diseases. Full article

Adipose-derived stem cells (ADSCs) are mesenchymal stem cells with a great potential for self-renewal and differentiation. Exosomes derived from ADSCs (ADSC-exos) can imitate their functions, carrying cargoes of bioactive molecules that may affect specific cellular targets and signaling processes. Recent evidence has shown that ADSC-exos can mediate tissue regeneration through the regulation of the inflammatory response, enhancement of cell proliferation, and induction of angiogenesis. At the same time, they may promote wound healing as well as the remodeling of the extracellular matrix. In combination with scaffolds, they present the future of cell-free therapies and promising adjuncts to reconstructive surgery with diverse tissue-specific functions and minimal adverse effects. In this review, we address the main characteristics and functional properties of ADSC-exos in tissue regeneration and explore their most recent clinical application in wound healing, musculoskeletal regeneration, dermatology, and plastic surgery as well as in tissue engineering. Full article