Search Results (147)

Tissue scaffolds are one of the main components of the tissue engineering triad, playing a vital role in tissue engineering. However, their production procedures heavily rely on solvent-intensive and energy-demanding methods. This raises serious questions about industrial-scale manufacturability, residual solvent toxicity to living health, and sustainability for nature and the environment. Therefore, the main aim of this study is to identify robust scaffolds that provide a suitable microenvironment for resident cells and promote tissue regeneration, while reducing waste through environmentally friendly production methods. In this context, the scalable and ecologically friendly production methods emerge as necessary alternatives as biodegradable polymer scaffolds are used in more therapeutic settings. Clinically applicable and green synthesis-based supercritical carbon dioxide (scCO₂) technologies, melt electrowriting (MEW), and solvent-free processing techniques are the main topics of this study for a critical analysis of biodegradable polymer scaffold production techniques. Scaffold structure–property correlations, polymer selection and interactions, production procedures, the benefits and drawbacks of existing fabrication technologies, and sustainability issues are discussed in detail. It aims to contribute a novel perspective and approach to literature by presenting and comparing production-oriented approaches as sustainable and green methods. The challenges in the development of biodegradable tissue scaffolds, along with the significance of green manufacturing techniques, are also revealed. The approach is designed to connect processing factors to scaffold features in addition to evaluating current technologies. This review tries to offer a framework for producing biodegradable polymer scaffolds in a sustainable and clinically implementable context. Full article

Endoscopic sinus surgery (ESS) is commonly performed to treat chronic rhinosinusitis and selected sinonasal tumors, yet postoperative complications such as neo-osteogenesis and restenosis remain frequent, largely due to impaired mucosal regeneration after extensive epithelial and bony tissue loss. Successful nasal epithelial repair requires a microenvironment that preserves cell viability, phenotype, and barrier integrity. Conventional culture substrates often lack physiological relevance or rely on animal-derived components, limiting translational applicability. In this study, we evaluated nanofibrillar cellulose (NFC) hydrogel (GrowDex^®) as a xeno-free scaffold for primary human nasal epithelial cells (NECs). NECs isolated from healthy donor tissue were characterized by immunofluorescence and qPCR for basal, goblet, and ciliated cell markers. Cells embedded in NFC were assessed for viability, cytotoxicity, epithelial morphology, and barrier function. Transepithelial electrical resistance (TEER) and FITC-dextran permeability assays were used to quantify barrier integrity and compared with collagen- and polylysine-based controls. NECs cultured in NFC maintained high viability, stable epithelial morphology, and preserved subtype-specific marker expression without detectable cytotoxicity. NFC-supported cultures demonstrated enhanced barrier formation, indicated by higher TEER values and reduced paracellular permeability relative to controls, and sustained structural integrity during extended culture. These findings identify NFC hydrogel as a biocompatible, non-animal scaffold that supports functional human nasal epithelium regeneration and may contribute to advanced tissue engineering strategies for craniofacial bone repair. Full article

Tendon-derived stem cells (TDSCs) are a unique cell population found in tendons, exhibiting both mesenchymal stem cell (MSC)-like phenotypes and tendon-specific markers. They have emerged as a promising research tool in tendon-related tissue engineering studies. However, there is currently no well-characterized TDSC line with MSC-related phenotypes for investigating tendon biology or developing therapeutics. Here, we established an immortalized monoclonal TDSC, named iTDSC#6, from the Achilles tendon of an adult male Sprague-Dawley rat. Cell clones were characterized for MSC-associated cell surface markers, colony formation capacity, and trilineage differentiation potentials, tenogenic potential and SV40LT expression at both early (passage < 10) and late (passage > 30) stages. iTDSC#6 showed stable expression of Simian virus 40 large T antigen (SV40LT) and demonstrated similar MSC-like phenotypes as its wild-type counterpart at both early and late passages, including colony formation capability and multi-lineage differentiation potentials. iTDSC#6 was positive for the MSC markers CD90, CD44, CD29 and CD73 (≥95%) and negative for the hematopoietic markers CD34 and CD45 (<1%). Regarding its utility for basic research and therapeutic development, iTDSC#6 showed potential for modelling cells with increased levels of senescence-associated beta-galactosidase activity in response to hydrogen peroxide and for bioengineering scaffold-free, tendon-like 3D constructs as evidenced by its upregulation of tendon-related markers, high nuclear aspect ratio, and aligned collagen organization. In conclusion, an immortalized TDSC line was successfully established that shows promise as a useful research tool to study tendon biology and aid the development of therapeutics for tissue engineering and regenerative medicine. Full article

While traditional 2D in vitro models have been widely used for drug screening, 3D tissue culture systems are gaining traction due to their superior ability to replicate in vivo tumor microenvironments. In this study, we utilize Microtissues™, a validated, scaffold-free, high-throughput 3D tissue culture platform, as the basis for a microscale tissue-engineered model to study drug absorption and transport dynamics. Despite their physiological relevance, such 3D constructs pose analytical challenges, particularly in quantifying trace drug levels within the microenvironment. We developed and validated an integrated experimental workflow combining optimized liquid–liquid extraction and protein precipitation with LC-MS/MS analysis to accurately quantify paclitaxel absorption in Microtissues™ molds using small sample volumes. The assay achieved a validated lower limit of quantification of 0.03 μM, with robust linearity across analytical runs (R² ≥ 0.90; best-run performance > 0.99) and precision (CV ≤ 10%) across both MRMs. This microengineered in vitro system allows for precise characterization of drug–tissue interactions in MCF7 breast cancer Microtissues™, enabling in vitro-to-in vivo extrapolation (IVIVE) relevant to therapeutic optimization. The platform’s scalability and modularity support its application in precision medicine, where patient-derived microtissues can guide individualized treatment decisions. Full article

Mesenchymal stem cells (MSCs) have been widely investigated in regenerative medicine owing to their immunomodulatory activity, paracrine signaling, and multilineage differentiation potential. However, accumulating clinical and preclinical evidence indicates that conventional MSC therapies based on single-cell injection often produce transient benefits due to rapid post-transplant cell loss and poor engraftment. These observations suggest that the limited efficacy of MSC therapy is not determined solely by cell type or disease context but may also be influenced by the delivery strategy. In this review, we focus on MSC-based cell sheet studies as an approach to improve cell retention and therapeutic persistence. Building on the clinical validation of cell sheet technology, we critically summarize preclinical evidence across distinct tissue environments. Preclinical studies in cardiac and cutaneous repair models demonstrate that MSC sheets enhance cell retention, sustain paracrine signaling, and promote tissue-level regeneration. Together, these findings highlight that effective MSC sheet therapy requires organ-specific, cell-source-dependent design strategies rather than a uniform approach across tissues. Finally, we propose that the MSC sheet engineering represents not a technical adjustment, but a conceptual shift from transient cell delivery toward structurally integrated, tissue-level regeneration engineering. Full article

Head and neck squamous cell carcinomas (HNSCCs) are considered the most common histological type of head and neck cancer. This study aims to develop a drug delivery system based on zein protein nanoparticles (Zein NPs) to enhance the therapeutic effect of the anticancer peptide, Pistacia zardin1 (PZ1), for the treatment of maxillofacial cancers. PZ1-Zein NPs were synthesized by the desolvation method. These spherical nanoparticles (size: 162.8 nm, PDI: 0.27) showed high encapsulation efficiency (89%) and pH-responsive release (with higher drug release in the acidic tumor microenvironment). In vitro cytotoxicity assays showed that PZ1-Zein NPs significantly reduced IC50 values in HNSCC cell lines (e.g., SCC-25: 7.5 µM vs. 19.3 µM for free peptide, p < 0.001) while exhibiting improved selectivity for cancer cells over normal HaCaT cells. Mechanistic investigations confirmed that PZ1-Zein NPs significantly increased apoptosis, as shown by increased caspase-3/7 activity (5.8-fold vs. 2.6-fold). These findings highlight PZ1-Zein NPs as a promising nanomedicine strategy and a candidate functional component for future dual-functional scaffolds aimed at targeted hard tissue engineering and surgery in HNSCC management. Full article

This study developed multifunctional chitosan–hydroxyapatite (CH–HAp) scaffolds incorporating cobalt ferrite (CoFe₂O₄, CFO) nanoparticles and carvacrol to combine bone regeneration potential with magnetic responsiveness and antimicrobial activity. Scaffolds containing 5 wt% CFO and 10–30 wt% carvacrol (free or Tween 80-emulsified) were fabricated via freeze-drying. The inclusion of CFO provided ferrimagnetic behavior, while carvacrol reduced chitosan crystallinity and increased scaffold porosity. Formulations with 30 wt% carvacrol demonstrated the strongest antimicrobial effect, showing inhibition halos against Staphylococcus aureus, Escherichia coli, Candida albicans, and Candida glabrata. The scaffold combining emulsified carvacrol and CFO exhibited a highly porous (≈90%) structure, preserved magnetic response, and mild cytotoxicity toward L929 fibroblasts, indicating cytocompatibility. The synergistic integration of CFO and carvacrol in a CH–HAp matrix yielded a multifunctional platform that simultaneously provides structural support, magnetic responsiveness, and antimicrobial performance, showing great promise for advanced bone tissue engineering applications. Full article

The tendon-to-bone enthesis is a multiphasic structure with four structurally continuous and compositionally distinct regions: tendon, uncalcified fibrocartilage, calcified fibrocartilage and bone. Our study aimed to develop 3D scaffold-free in vitro spheroids and macro-tissues of the enthesis for applications as experimental tools to understand the development and repair of enthesis injury. This study hypothesises that integrating tendon and bone cell spheroids with bone marrow mesenchymal stem cell spheroids will facilitate the production of a fibrocartilaginous interface. 3D Spheroids: The biphasic (tendon–bone) and triphasic co-culture (tendon–stem cell–bone) of spheroids in growth media and chondrogenic media were investigated to establish fusion kinetics, and the cellular and ECM components produced via histology and immunohistochemistry. Complete fusion between spheroids occurred within 6-to-8 days in biphasic co-culture, and 15-to-20 days in triphasic co-culture. Compared to biphasic, the triphasic co-culture in chondrogenic media showed a continuous interface connecting the tendon and bone regions. The presence of collagen I, sulphated proteoglycans and collagen type II in the interface region of triphasic co-culture indicates fibrochondrogenic differentiation. 3D macro-tissues: The modular tissue engineering strategy was used in this study to produce enthesis macro-tissues using spheroids as building blocks. Spheroids were bio-assembled in the triphasic manner (12 tendon spheroids, 12 stem cell spheroids and 8 bone spheroids) in the custom-designed and 3D-printed temporary supports (Formlabs Clear Resin^®) using a customised spheroid bio-assembly system. The fusion of spheroids occurred by day 8 after bio-assembly, and they were removed from temporary supports and cultured in scaffold-free conditions. Although the bio-assembly methodology was successful in producing fused scaffold-free macro-tissues, the histological analysis revealed the presence of an extensive necrotic core due to the large-sized constructs. To conclude, the findings support the hypothesis that a triphasic co-culture has the potential to produce a structurally continuous fibrocartilaginous interface but requires further optimisation to produce macro-tissues with anatomical morphologies and reduced necrotic cores. Full article

Diabetic wounds remain chronically non-healing due to impaired angiogenesis, persistent inflammation, and defective extracellular matrix remodelling. In recent years, stem cell-derived exosomes have emerged as a potent cell-free regenerative strategy capable of recapitulating the therapeutic benefits of mesenchymal stem cells while avoiding risks associated with direct cell transplantation. This review critically evaluates the preclinical evidence supporting the use of exosomes derived from adipose tissue, bone marrow, umbilical cord, and induced pluripotent stem cells for diabetic wound repair. These exosomes deliver bioactive cargos such as microRNAs, proteins, lipids, and cytokines that modulate key signalling pathways, including Phosphatidylinositol 3-kinase/Protein kinase (PI3K/Akt), Nuclear factor kappa B (NF-κB), Mitogen-activated protein kinase (MAPK), Transforming growth factor-beta (TGF-β/Smad), and Hypoxia inducible factor-1α/Vascular endothelial growth factor (HIF-1α/VEGF), thereby promoting angiogenesis, accelerating fibroblast and keratinocyte proliferation, facilitating re-epithelialization, and restoring immune balance through M2 macrophage polarization. A central focus of this review is the recent advances in exosome-based delivery systems, including hydrogels, microneedles, 3D scaffolds, and decellularized extracellular matrix composites, which significantly enhance exosome stability, retention, and targeted release at wound sites. Comparative insights between stem cell therapy and exosome therapy highlight the superior safety, scalability, and regulatory advantages of exosome-based approaches. We also summarize progress in exosome engineering, manufacturing, quality control, and ongoing clinical investigations, along with challenges related to standardization, dosage, and translational readiness. Collectively, this review provides a comprehensive mechanistic and translational framework that positions stem cell-derived exosomes as a next-generation, cell-free regenerative strategy with the potential to overcome current therapeutic limitations and redefine clinical management of diabetic wound healing. Full article

To address the challenges in wound healing, clinical management increasingly demands targeted, adaptive, responsive, and patient-centered strategies. This is especially true for wounds characterized by delayed healing and a high risk of infection. Advances in regenerative medicine and biomaterial technologies are fostering the development of multifunctional approaches that integrate tissue regeneration, antibacterial/antibiofilm activity, immunomodulation, and real-time monitoring. This paper surveys emerging platforms, including both natural and synthetic scaffolds, hydrogels enriched with platelet-derived growth factors, glycosaminoglycan mimetics, bioactive peptides (such as GHK-Cu and antimicrobial peptides), nanoscaffolds, and stimuli-responsive systems. The paper also explores cutting-edge technologies such as water-powered, electronics-free dressings that deliver localized electrical stimulation; biodegradable bioelectric sutures that produce self-sustained mechano-electrical signals; and sensory bandages that monitor pH, moisture, temperature, and bacterial contamination in real-time while enabling on-demand drug release with pro-regenerative, antibacterial, and other therapeutic functionalities. Further therapeutic approaches include natural matrices, exosomes, gene editing, 3D bioprinting, and AI-assisted design. Particular attention is paid to orthopedic applications and orthopedic implant infection. A brief section addresses the still unresolved challenge of articular cartilage regeneration. Interdisciplinary innovation, integrating insights from molecular biology through engineering, plays a central role in translating novel strategies into tailored, clinically effective wound management solutions. Full article

Extracellular vesicles (EVs) derived from stem cells have emerged as promising mediators of osteogenesis, suggesting cell-free alternatives for bone tissue engineering and regenerative medicine. This review provides a comprehensive analysis of the main stem cell sources used for EV production, including bone marrow mesenchymal stem cells (BM-MSCs), adipose-derived stem cells (ADSCs), umbilical cord MSCs (UC-MSCs), induced pluripotent stem cells (iPSCs), and alternative stromal populations. Particular attention is given to the ways in which different conditioning and differentiation strategies, such as osteogenic induction, hypoxia, and mechanical stimulation, modulate EV cargo composition and enhance their therapeutic potential. We further discuss the in vitro models employed to evaluate EV-mediated bone regeneration, ranging from 2D cultures to complex 3D spheroids, scaffold-based systems, and bone organoids. Overall, this review emphasizes the current challenges related to standardization, scalable production, and clinical translation. It also outlines future directions, including bioengineering approaches, advanced preclinical models, and the integration of multi-omics approaches and artificial intelligence to optimize EV-based therapies. By integrating current knowledge, this work aims to guide researchers toward more consistent and physiologically relevant strategies to harness EVs for effective bone regeneration. Finally, this work uniquely integrates a comparative analysis of EVs from multiple stem cell sources with engineering strategies and emerging clinical perspectives, thereby providing an updated and translational framework for their application in bone regeneration. Full article

The development of advanced delivery systems for bioactive factors is a critical focus in regenerative medicine and tissue engineering. In this study, we present a waterborne polyurethane (WPU)-based scaffold fabricated through a fully aqueous electrospinning process, providing a solvent-free and green method for delivering secretome derived from human mesenchymal stromal cells (MSCs). We optimized the electrospinning parameters to enable efficient secretome incorporation while preserving fiber morphology, sterility, and biocompatibility. The resulting membranes exhibited a uniform nanofibrous architecture, supported high cell viability, and demonstrated effective secretome loading and release, detected following release of vascular endothelial growth factor (VEGF)-A over 24 h. Overall, our findings highlight the potential of WPU nanofibrous scaffolds as sustainable and functional platforms for the delivery of MSC-derived bioactive factors in biomedical applications. Full article

Hydrothermal treatment was investigated as a strategy to enhance the supercritical CO₂ foaming process for the fabrication of polycaprolactone (PCL) scaffolds intended for tissue engineering applications. PCL samples were subjected to supercritical foaming at 300 bar and 40 °C for 60 min, combined with hydrothermal treatments performed either before or after foaming at temperatures of 70–100 °C and pressures of 10–20 bar. The effects of these treatments on scaffold morphology, porosity, and mechanical behavior were evaluated using scanning electron microscopy, micro-computed tomography, and compression testing. The results showed that hydrothermal treatment prior to foaming significantly improved scaffold porosity from 16.5% (untreated PCL) up to 57.9% while increasing pore interconnectivity (up to 156.8 throats mm⁻³). Conversely, post-foaming hydrothermal treatment led to pore collapse and loss of structural integrity. The pre-treated scaffolds maintained compressive moduli within 2–12 MPa, consistent with values required for bone tissue engineering. In vitro degradation in PBS revealed a moderate increase in weight loss (~10% after 90 days), indicating that the hydrothermal step slightly accelerates polymer hydrolysis without compromising stability. These findings demonstrate that combining hydrothermal pre-treatment with supercritical CO₂ foaming provides a solvent-free route to tailor scaffold morphology and mechanical performance, offering a sustainable alternative for the design of bioresorbable materials in regenerative medicine. Full article

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