Search Results (444)

Objective: Effectively eliminating xenoimmunogenicity and achieving recellularization in cardiac xenografts remains a critical challenge in developing an ideal implantable xenograft. We have previously demonstrated that the removal of major antigens, including Galα1-3Gal (α-Gal) epitope and non-human sialic acid N-glycolylneuraminic acid (Neu5Gc), using α-galactosidase and peptide N-glycosidase F (PNGase-F), enables a synergistic effect with decellularization, significantly reducing the expression of carbohydrate-binding lectins without altering the biomechanical properties of the graft. The aim of this study was to establish an effective method for in vitro recellularization by seeding human mesenchymal stem cells (MSCs) on decellularized cardiac xenografts that had undergone optimal xenoantigen removal using α-galactosidase and PNGase-F. Additionally, this study aimed to evaluate the potential for in vivo recellularization. Methods: Decellularized porcine pericardium scaffolds treated with both enzymes were further modified by forming a fibrin mesh on their surface and within their structure, followed by the attachment of heparin and human vascular endothelial growth factor to the mesh. Subsequently, the scaffolds were seeded with human adipose tissue-derived stem cells for 8 weeks. In vitro recellularization, differentiation, and extracellular matrix remodeling of decellularized and enzyme-treated xenografts were assessed using vimentin, calponin, fibronectin, CD31, VWF, and phalloidin staining. To evaluate the potential for in vivo recellularization, decellularized glutaraldehyde-crosslinked xenografts with anticalcification treatments were seeded with rat bone marrow MSCs and implanted into rats subcutaneously to evaluate cell infiltration and calcification via histology, von Kossa staining, and micro-computed tomography. Results: In decellularized xenografts treated with both enzymes, stronger signals were detected and mesenchymal cell infiltration into the tissue was significantly faster, leading to accelerated recellularization. This recellularization process was more pronounced as time went on, with greater cell infiltration and evidence of cell differentiation. An in vivo study showed that decellularization and anticalcification treatments revealed stronger vimentin staining in histological analysis. The recellularization for our biocompatible scaffolds exhibited a lower degree of calcification compared to the non-recellularized tissue. Conclusions: We successfully developed major xenoantigen-free scaffolds by demonstrating the safety and synergistic effect of α-galactosidase and PNGase-F treatments and proved, for the first time, the effectiveness of recellularization using a human MSC monoculture on xenoantigen-free scaffolds. Furthermore, there was potential for in vivo recellularization of our biocompatible scaffolds seeded with MSCs. Full article

Stress urinary incontinence (SUI) affects a significant proportion of women and often requires surgical intervention when conservative treatments fail. While midurethral slings (MUS) are widely used, concerns over complications such as mesh exposure/erosion and chronic pain have driven interest in regenerative medicine alternatives. This review explores emerging strategies, including stem cell therapies, platelet-rich plasma injections, decellularized extracellular matrix scaffolds, injectable hydrogels, and bioengineered slings. These approaches aim to restore continence by promoting tissue regeneration, improving biocompatibility, and reducing adverse reactions. We evaluate their mechanisms, reported outcomes, and current stage of development, supported by in vitro and in vivo model data. Although promising, these technologies face challenges related to cell viability, scaffold integration, and clinical translation. Continued interdisciplinary research is essential to optimize these therapies and bring safer, more effective solutions to patients. Regenerative strategies may ultimately redefine the future of SUI treatment by offering biologically integrated, long-lasting alternatives to synthetic slings. To date, no tissue-engineered or regenerative biomimetic sling has received regulatory approval for routine clinical use in the management of stress urinary incontinence. Full article

Demineralized bone matrices (DBMs) are widely used in bone replacement therapy. Bone tissue of either cancellous or cortical origin is decellularized, demineralized, and sterilized during processing, while retaining portions of native organic extracellular matrix (ECM) proteins that regulate cell–matrix interactions during bone repair. The ECM largely accounts for the distinct functions of cortical and cancellous bone. Differences in three-dimensional architecture and matrix density between cancellous and cortical bone may therefore affect ECM proteome signatures and the resulting cellular microenvironment. In this study, ECM proteins were extracted from processed cancellous and cortical allografts at multiple processing steps and analyzed by quantitative mass spectrometry. We identified distinct extractable proteome signatures associated with bone metabolic functions. Cancellous grafts were relatively enriched in proteins associated with inflammatory, coagulative, and immune-related processes, whereas cortical grafts showed higher abundance of structural and matrix-organization-associated proteins. More extensively processed product formats showed fewer significant protein differences between the cortical and cancellous bone type. Within the limitations of pooled donor material and absent functional validation, these findings provide a proteomic framework for future characterization and evaluation of DBM-based allograft products. Full article

Diabetic wounds are a common and severe complication of diabetes mellitus, characterized by delayed healing due to persistent inflammation, impaired angiogenesis, and cellular dysfunction. Conventional therapeutic approaches remain limited in efficacy. In recent years, exosomes have attracted considerable attention in wound healing and regenerative medicine because of their crucial role in intercellular communication and tissue repair. However, rapid clearance of exosomes in vivo greatly limits their therapeutic efficacy. To address this critical limitation, we engineered a decellularized extracellular matrix (dECM)-based hydrogel system functionalized with exosomes derived from skin-derived precursor cells (SKPs). This biomimetic scaffold was designed to serve as a local exosome-delivery platform at the wound site, with the aim of improving exosome utilization and augmenting their regenerative effects. Comprehensive in vitro characterization demonstrated that the exosome-loaded composite hydrogels exhibited robust pro-angiogenic activity, as evidenced by enhanced endothelial cell proliferation, migration, and tube formation. Moreover, the hydrogels displayed significant antibacterial effects against wound-relevant pathogens and potent reactive oxygen species (ROS)-scavenging capacity, thereby mitigating oxidative damage. Notably, the composite hydrogels also promoted the phenotypic polarization of macrophages toward the pro-regenerative M2 phenotype. In parallel, in vivo studies using a streptozotocin-induced diabetic rat wound model confirmed that treatment with the composite hydrogels significantly accelerated wound closure rates compared to control groups. Histological and immunohistochemical analyses revealed enhanced angiogenesis, as evidenced by increased CD31-positive microvessel density, as well as improved collagen deposition, re-epithelialization, and an attenuated local inflammatory microenvironment characterized by reduced pro-inflammatory cytokine expression and elevated M2 macrophage infiltration. Collectively, the SKPs exosome-loaded dECM based composite hydrogels developed in this study represent a potential therapeutic strategy for the treatment of diabetic wounds. Full article

Decellularized extracellular matrix (dECM) scaffolds derived from xenogeneic tissues represent promising biomaterials for tissue engineering. In this study, dECM scaffolds were developed and characterized from four ovine tissues—skin, tunica vaginalis, fascia lata, and pericardium—using a detergent-based decellularization protocol to evaluate decellularization efficiency and extracellular matrix (ECM) preservation. Decellularization was performed using a sequential detergent-based protocol with sodium dodecyl sulfate and Triton X-100. Decellularization efficacy and matrix preservation were evaluated through gross examination, histological analysis, scanning electron microscopy (SEM), and residual DNA quantification. Gross inspection revealed increased translucency and reduced pigmentation in decellularized tissues compared with native counterparts, indicating effective cellular removal while maintaining overall tissue architecture. Histological assessment confirmed the complete absence of nuclear and cytoplasmic material, alongside preservation of collagen-rich extracellular matrix organization. SEM analysis demonstrated well-maintained ultrastructural features, including aligned collagen fibers and porous ECM architecture, with complete removal of epithelial and stromal cellular elements. Quantitative analysis revealed approximately 94% reduction in residual DNA content across all decellularized tissues compared with native controls. This study demonstrated that the employed detergent-based protocol reliably produces structurally preserved, acellular scaffolds from multiple ovine tissues. The resulting biomaterials exhibit structural characteristics that support their potential use in tissue engineering applications, pending further functional validation. Full article

Pulmonary bioengineering holds significant promise for the development of functional lungs suitable for transplantation in patients with terminal lung diseases; however, it encounters considerable challenges. The inherent structural complexity, diverse cellular composition, and the intricate process of re-endothelialization the pulmonary vasculature complicate efforts to reconstruct viable lungs for transplantation. This study aimed to establish an innovative re-endothelialization technique utilizing decellularized scaffolds, integrating canine yolk sac-derived endothelial precursor cells with mechanical respiratory stimuli within a bioreactor framework. Wistar rat lungs were subjected to a decellularization protocol employing SDS + Triton X-100 0.5% and subsequently assessed for cytocompatibility with murine fibroblasts (3T3) and yolk sac (YS) cells in fragments. Following this, the recellularization of the whole-lung scaffold was evaluated under constant mechanical respiratory stimulation with YS cells. Each stage of the process was rigorously analyzed using histological staining, DAPI, scanning electron microscopy (SEM), and genomic DNA quantification. The findings reveal that the implemented alternating decellularization protocol resulted in a structured scaffold conducive to the culture of various cell types in fragments. When subjected to the complete scaffold recellularization model, the results indicated that YS cells are advantageous for the re-endothelialization process. Moreover, when employed in conjunction with the bioreactor model incorporating respiratory stimulation, these cells demonstrated enhanced cellular diffusion capacity and facilitated more homogeneous recellularization of the entire organ. These results signify a notable advancement in the reconstruction of new tissues for pulmonary transplantation. Full article

Oral mucosal ulcers sustain a persistent inflammatory and oxidative microenvironment that interferes with epithelial repair and delays healing. Although hyaluronic acid (HA) is used in oral wound management due to its biocompatibility and hydrating properties, its biological activity is highly context-dependent and can be compromised under inflammatory conditions. In contrast, N-acetyl-L-cysteine (NAC) is a well-established antioxidant with documented anti-inflammatory effects, yet its rapid clearance limits its effectiveness when applied locally. In this study, the effects of HA and NAC, individually and in combination, on metabolic activity and inflammatory responses of TNF-α–stimulated human gingival keratinocytes were evaluated. In parallel, the individual immobilization of HA or NAC onto plasma-activated decellularized extracellular matrix (dECM) films was investigated as a materials-oriented approach for potential localized intraoral applications. NAC significantly attenuated TNF-α-induced IL-6 and IL-8 secretion, reducing both cytokines by approximately 99%, while preserving keratinocyte metabolic activity. HA displayed limited immunomodulatory effects. The combined HA + NAC condition did not improve the response compared with NAC alone. Plasma treatment enabled stable individual grafting of HA and NAC onto dECM films, and both functionalized surfaces retained chemical stability under saliva-like conditions. Collectively, these findings identify NAC as the most effective anti-inflammatory candidate under the tested cellular conditions and support plasma-functionalized dECM films as a feasible platform for future biological evaluation in intraoral applications. Full article

Braided nerve guidance conduits (NGCs) composed of decellularized porcine small intestinal submucosa (SIS) were developed to achieve an appropriate balance between mechanical performance and biological compatibility for peripheral nerve repair. This study aimed to compare four SIS-braided conduits with silicone tubes in terms of bending compliance, tensile strength, swelling behavior, and cytocompatibility. SIS-braided conduit exhibited a favorable combination of flexibility, tensile strength, and dimensional stability. In vitro evaluations using PC12 and SW10 cells demonstrated that SIS-braided conduit supported neurite outgrowth and Schwann cell adhesion, confirming its favorable cytocompatibility. Based on these findings, SIS-braided conduits and silicone tubes were subsequently evaluated in a rat sciatic nerve defect model. Functional recovery assessed using the Sciatic Functional Index suggested preliminary functional recovery in the SIS-braided conduit, and histological analyses revealed evidence of axonal regeneration and myelin formation within the conduit. Overall, the results indicate that the integration of mechanical robustness with biological activity is essential for the design of nerve graft substitutes. The conduit braided from decellularized small intestinal submucosa represents a promising biodegradable alternative, a considerable biodegradable alternative to conventional non-degradable silicone conduits for peripheral nerve repair. Full article

The regeneration and repair of scarless skin tissue remain a significant challenge for full-thickness wounds. Traditional wound management approaches, particularly passive healing through scabbing and conventional mechanical debridement, are frequently associated with significant pain, high infection risks, and abnormal scar formation, often failing to support the regeneration of skin appendages like hair follicles. In recent years, collagen-based scaffolds have been widely adopted in tissue-engineered skin substitutes owing to their favorable biocompatibility. However, their simplistic, single-component architecture inherently lacks the dynamic, cell-instructive microenvironment found in native skin, which not only compromises the long-term survival and functional integration of seeded cells but also directly leads to insufficient reconstruction of the dermo-epidermal junction, thereby impairing skin barrier function and ultimately limiting overall regenerative efficacy. In this study, we propose a biomimetic multilayer composite scaffold system in which decellularized amniotic membrane matrix (AM) is combined with fibroblast-laden collagen gel (FCG) and seeded with epidermal stem cells (EpiSCs). This bionic skin (denoted as AM-FCG-EpiSCs) is designed to achieve hierarchical regeneration of full-thickness skin defects. Compared with injured skin treated with Moropicin ointment, the injured skin treated with AM-FCG-EpiSCs healed more quickly and regenerated appendages like hair follicles without scarring. The results show that the biomimetic structure of AM-FCG-EpiSCs can mediate dynamic cell–cell interactions and regulate the microenvironment. This breakthrough overcomes the dual challenges of scar suppression and functional restoration in full-thickness skin regeneration, offering an innovative solution for translational medicine. Full article

The liver possesses a remarkable regenerative capacity following injury, a process fundamentally orchestrated by the dynamic extracellular matrix (ECM). Far beyond a passive scaffold, the liver matrisome functions as an integrative mechano-biochemical circuit. It comprises a core structural network together with regulatory non-core components that collectively establish a dynamic niche. This niche stores and releases mitogenic cues, transmits mechanical forces, and coordinates multicellular crosstalk. Through receptors like integrins and mechanosensitive channels, ECM-derived signals converge on key pathways, including Hippo-YAP/TAZ and Wnt/β-catenin, to drive hepatocyte proliferation and tissue restructuring. The balance between matrix stabilization and remodeling dictates the outcome, guiding physiological regeneration versus fibrotic progression. Consequently, the ECM emerges as a central therapeutic target and a blueprint for engineering strategies aimed at restoring liver function. Strategies to recalibrate its composition, mechanics, and remodeling, from pharmacological inhibitors to bioengineered decellularized ECM scaffolds, hold significant potential for steering liver repair and combating chronic liver disease. Full article

In regenerative medicine, three-dimensional (3D) printing provides precise spatial control over the fabrication of complex, biomimetic tissue constructs, enabling the production of architecturally defined and functionally tailored scaffolds. By enabling precise layer-by-layer deposition of cells, biomaterials, and bioactive compounds, 3D printing overcomes many limitations associated with conventional scaffold fabrication methods. This approach facilitates the development of tailored structures that mimic the mechanical, biological, and structural characteristics of native tissues, thereby enhancing cellular organization, proliferation, and differentiation. Extensive research in tissue engineering has led to the development of 3D-printed scaffolds for the regeneration of vascular, skin, bone, cartilage, and soft tissues. Advances in bioink formulations—including growth factor-loaded systems, decellularized extracellular matrix components, and natural and synthetic polymers—have further improved tissue-specific functionality. Moreover, multimaterial and multiscale printing strategies enable the fabrication of heterogeneous constructs with controlled porosity, mechanical gradients, and spatially regulated biological cues. Although vascularized tissue constructs remain a major challenge for clinical translation, recent bioprinting advancements have significantly accelerated progress in this area. Integration of computer-aided design with patient-specific imaging data has further strengthened the potential of 3D printing for personalized regenerative therapies. Despite these advances, challenges related to scalability, regulatory approval, and long-term functionality persist. Nevertheless, continued progress in printing technologies, biomaterials, and regulatory and standards frameworks is expected to drive the clinical adoption of 3D printing. Ultimately, 3D printing represents a transformative approach in tissue engineering, redefining strategies for functional tissue regeneration and translational regenerative medicine. Full article

End-stage liver disease caused by advanced fibrosis and cirrhosis remains a major global burden, yet its treatment is limited by donor organ shortages. Bioengineered liver scaffolds offer a promising alternative, but their efficacy is often limited by thrombosis, insufficient vascularization, and poor graft integration due to inadequate endothelialization. To overcome these challenges, we employed LXW7 αvβ3 integrin targeting peptide with high endothelial cell specificity and low platelet affinity to enhance re-endothelialization and hemocompatibility of decellularized liver scaffold (DLS) and thereby improve hepatic integration and function. LXW7 was covalently conjugated to the decellularized rat liver scaffold via EDC/NHS-mediated carbodiimide coupling and subsequently reseeded with human umbilical vein endothelial cells (HUVECs) and cultured in a perfusion bioreactor to promote endothelialization. LXW7 immobilization significantly improved HUVECs attachment and proliferation, achieving approximately 81% vascular coverage, while sustaining the endothelial function. Ex vivo blood perfusion showed minimal thrombus formation and markedly reduced platelet adhesion, demonstrating enhanced hemocompatibility. Following confirmation of endothelialization, scaffolds were recellularized with hepatocellular carcinoma (HepG2) cells and HUVECs. LXW7 modified scaffolds promote organized hepatocyte distribution, sustained albumin expression, and increased urea secretion. In vivo implantation of LXW7-DLS into the omentum of mice promoted robust host endothelial recruitment and enhanced neovascularization, highlighting the scaffold’s excellent biocompatibility and good integration with surrounding tissues. Moreover, in vivo implantation of LXW7 recellularized scaffolds into a thioacetamide-induced fibrotic mouse liver resulted in reduced collagen deposition and lowered serum ALT/AST levels, demonstrating hepatic regeneration and extracellular matrix remodeling. Overall, our results showed that LXW7-modified DLS promotes stable endothelialization, improves hemocompatibility, and enhances hepatic function, underscoring its translational potential for the development of vascularized transplantable liver grafts. Full article

Adipose tissue engineering (ATE) is an interdisciplinary field integrating materials science, cell biology, and engineering, aiming to construct functional artificial adipose tissue for addressing adipose tissue deficiency, metabolic disorders, and related clinical challenges. This review systematically summarizes the core advances, critical limitations, and translational potential of ATE. First, we elaborate on the three fundamental elements of ATE: scaffold materials (hydrogels, porous materials, microspheres, fibrous materials, decellularized extracellular matrix, 3D-printed/bioprinted scaffolds, and prevascularized constructs), seed cells (adipose-derived stem cells, mesenchymal stem cells, etc.), and growth factors (vascular endothelial growth factor, fibroblast growth factor, etc.), as well as their synergistic regulatory roles in adipose tissue regeneration. We then discuss the key factors influencing adipogenic differentiation and vascularization, which are pivotal for the formation of functional ATE constructs. Furthermore, we detail the construction and evaluation of in vitro and in vivo ATE models, highlighting the value of large animal models in bridging preclinical and clinical gaps. The applications of ATE in soft tissue repair and reconstruction, drug screening and disease modeling, and cultured meat manufacturing are comprehensively analyzed, with emphasis on technical challenge across different directions. Finally, we discuss the core challenges hindering ATE clinical translation, including lack of standardization of adipose-derived stem cells, immunogenicity issues, regulatory barriers, and technical limitations, and propose targeted future perspectives. This review provides a comprehensive and critical overview of ATE, offering guidance for promoting its translation from preclinical research to clinical practice and industrial application. Full article

Decellularization removes immunogenic intracellular components of fish tissues while keeping the extracellular matrix (dECM) structure, mechanical integrity, and bioactivity. Fish-derived dECM retains native bioactive components, exhibiting high biocompatibility, low immunogenicity, and biodegradability, while supporting cell adhesion, proliferation, and tissue regeneration. Due to its abundance, minimal ethical concerns, and low zoonotic risks, fish wastes are emerging as sustainable sources of dECM, offering an eco-friendly alternative to mammalian biomaterials. This review highlights advances in decellularizing fish wastes such as skin, scales, bones, viscera, and swim bladders from species including tilapia, tuna, milkfish, carp, goldfish, and sturgeon. Physical, chemical, biological, and hybrid decellularization methods are assessed for cell removal, ECM preservation, and mechanical performance. Recent advances in polymer-dECM composites, crosslinking, and 3D bioprinting have significantly improved scaffold performance, making fish-derived dECM applicable for healing of wounds, regeneration of bone and cartilage, and repair of soft tissues. Despite its potential, challenges remain in optimizing perfusion rates, temperature variations, and tissue-specific protocols, as well as developing eco-friendly decellularization techniques using biodegradable reagents. Future perspectives include expanding decellularized fish tissue sources, innovating bio-inks for 3D bioprinting, and refining tissue-specific processing methods to maximize the potential of fish-derived dECM in regenerative medicine and tissue engineering. Full article