Search Results (45)

Autologous fat grafting is the main surgical technique for soft tissue reconstruction. However, its clinical use with more extended volumes is limited by repeated procedures due to the little possibility of banking tissue, donor-site morbidity and unpredictable graft resorption rates. To overcome these problems, adipose tissue engineering has focused on developing injectable scaffolds. Most of them are hydrogels that closely mimic the biological, structural and mechanical characteristics of native adipose tissue. This review provides an overview of current injectable scaffolds designed to restore soft tissue volume defects, emphasizing their translational potential and future directions. Natural injectable scaffolds exhibit excellent biocompatibility but degrade rapidly and lack mechanical strength. Synthetic injectable scaffolds provide tunable elasticity and degradation rates but require biofunctionalization to support cell adhesion and tissue integration. Adipose extracellular matrix-derived injectable scaffolds are fabricated by decellularization of adipose tissue. Accordingly, they combine bio-mimetic structure with intrinsic biological cues that stimulate host-driven adipogenesis and angiogenesis, thus representing a translatable “off-the-shelf” alternative to autologous fat grafting. However, despite this broad spectrum of available injectable scaffolds, the establishment of clinically reliable soft tissue substitutes capable of supporting large-volume and long-lasting soft tissue reconstruction still remains an open challenge. 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

Decellularized extracellular matrix (dECM) scaffolds preserve native tissue structure and biochemical cues while minimizing immune responses, creating biomimetic templates that promote cell integration and tissue remodeling. This review examines the current state of dECM research, encompassing decellularization methods, scaffold quality evaluation assays, and tissue-specific applications across dermis, nerve, heart, lung, adipose, and placental ECMs. We analyze commercially available dECM products and ongoing clinical trials, while highlighting recent advances including 3D bioprinting and the integration of dECM with stem cells and growth factors. Despite these promising developments, several challenges continue to limit broader clinical translation: protocol standardization, residual immunogenicity, mechanical durability, and regulatory, manufacturing, and cost barriers. To address these limitations, we outline future directions focusing on patient-specific scaffolds, scalable bioprocessing, and integrated biofabrication strategies that will enable the development of safe and effective dECM-based therapies. Full article

This study evaluates the effects of two decellularization protocols, enzyme-detergent (ED) and detergent-detergent (DD), on the structural and biomechanical properties of human urethral tissue. Urethral samples from 18 individuals were divided into ED (n = 7) and DD (n = 11) groups, with native samples (n = 3) serving as controls. Histological and ultrastructural analyses confirmed that both protocols effectively removed cellular content while preserving essential extracellular matrix (ECM) elements, such as collagen and elastic fibers. Immunohistochemical staining for collagen IV and fibronectin revealed no significant differences between decellularized and native tissues, indicating intact ECM structure. Biomechanical testing demonstrated that DD-treated tissues had significantly lower Cauchy stress (1494.8 ± 518.4 kPa) when compared to native tissues (2439.7 ± 578.7 kPa, p = 0.013), while ED-treated tissues were similar to both groups. Both decellularized groups exhibited reduced stretch at failure and elastic modulus compared to native tissues. Cytotoxicity assays using adipose-derived stem cells demonstrated no signs of toxicity in either protocol. Overall, both ED and DD protocols effectively preserved the urethral ECM structure and mechanical properties, making them suitable for potential use in tissue-engineered grafts and for biobanking purposes. Further research is needed to refine and optimize decellularization methods to improve scaffold recellularization and ensure clinical safety and efficacy. Full article

Osteochondral lesions may be due to trauma or congenital conditions. In both cases, therapy is limited because of the difficulty of tissue repair. Tissue engineering is a promising approach that relies on designed scaffolds with variable mechanical attributes to favor cell attachment and differentiation. Human adipose-derived stem cells (hASCs) are a very promising cell source in regenerative medicine with osteochondrogenic potential. Based on the assumption that stiffness influences cell commitment, we investigated three different scaffolds: a semisynthetic animal-derived GelMA hydrogel, a combined scaffold made of rigid PEGDA coated with a thin GelMA layer and a decellularized plant-based scaffold. We investigated the role of different biomechanical stimulations in the scaffold-induced osteochondral differentiation of hASCs. We demonstrated that all scaffolds support cell viability and spontaneous osteochondral differentiation without any exogenous factors. In particular, we observed mainly osteogenic commitment in higher stiffness microenvironments, as in the plant-based one, whereas in a dense and softer matrix, such as in GelMA hydrogel or GelMA-coated-PEGDA scaffold, chondrogenesis prevailed. We can induce a specific cell commitment by combining hASCs and scaffolds with particular mechanical attributes. However, in vivo studies are needed to fully elucidate the regenerative process and to eventually suggest it as a potential approach for regenerative medicine. Full article

Myocardial infarction (MI) is a serious cardiovascular disease as the leading cause of death globally. Hence, reconstruction of the cardiac tissue comes at the forefront of strategies adopted to restore heart functions following MI. In this investigation, we studied the capacity of rat adipose-derived mesenchymal stem cells (r-AdMSCs) and decellularized porcine pericardium (DPP) to restore heart functions in MI animals. MI was induced in four different groups, three of which were treated either using DPP (MI-DPP group), stem cells (MI-SC group), or both (MI-SC/DPP group). Cardiac functions of these groups and the Sham group were evaluated using echocardiography, the intraventricular pressure gradient (IVPG) on weeks 2 and 4, and intraventricular hemodynamics on week 4. On day 31, the animals were euthanized for histological analysis. Echocardiographic, IVPG and hemodynamic findings indicated that the three treatment strategies shared effectively in the regeneration process. However, the MI-SC/DPP group had a unique synergistic ability to restore heart functions superior to the other treatment protocols. Histology showed that the MI-SC/DPP group presented the lowest (p < 0.05) degeneration score and fibrosis % compared to the other groups. Conclusively, stem cell-seeded DPP is a promising platform for the delivery of stem cells and restoration of heart functions post-MI. Full article

Skeletal muscle tissue engineering (TE) and adipose tissue engineering have undergone significant progress in recent years. This review focuses on the key findings in these areas, particularly highlighting the integration of 3D bioprinting techniques to overcome challenges and enhance tissue regeneration. In skeletal muscle TE, 3D bioprinting enables the precise replication of muscle architecture. This addresses the need for the parallel alignment of cells and proper innervation. Satellite cells (SCs) and mesenchymal stem cells (MSCs) have been utilized, along with co-cultivation strategies for vascularization and innervation. Therefore, various printing methods and materials, including decellularized extracellular matrix (dECM), have been explored. Similarly, in adipose tissue engineering, 3D bioprinting has been employed to overcome the challenge of vascularization; addressing this challenge is vital for graft survival. Decellularized adipose tissue and biomimetic scaffolds have been used as biological inks, along with adipose-derived stem cells (ADSCs), to enhance graft survival. The integration of dECM and alginate bioinks has demonstrated improved adipocyte maturation and differentiation. These findings highlight the potential of 3D bioprinting techniques in skeletal muscle and adipose tissue engineering. By integrating specific cell types, biomaterials, and printing methods, significant progress has been made in tissue regeneration. However, challenges such as fabricating larger constructs, translating findings to human models, and obtaining regulatory approvals for cellular therapies remain to be addressed. Nonetheless, these advancements underscore the transformative impact of 3D bioprinting in tissue engineering research and its potential for future clinical applications. Full article

Tissue-relevant O₂ levels are considered as an important tool for the preconditioning of multipotent mesenchymal stromal cells (MSCs) for regenerative medicine needs. The present study investigated the quality and functions of the extracellular matrix (ECM) of MSCs under low O₂ levels. Human adipose tissue-derived MSCs were continuously expanded under normoxia (20% O₂, N) or “physiological” hypoxia (5% O₂, Hyp). Decellularized ECM (dcECM) was prepared. The structure of the dcECM was analyzed using confocal laser and scanning electron microscopy. Collagen, dcECM-N, and dcECM-Hyp were recellularized with MSC-N and further cultured at normoxia. The efficacy of adhesion, spreading, growth, osteogenic potential, and paracrine activity of recellularized MSC-N were evaluated. At low O₂, the dcECM showed an increased alignment of fibrillar structures and provided accelerated spreading of MSC-N, indicating increased dcECM-Hyp stiffness. We described O₂-dependent “ECM-education” of MSC-N when cultured on dcECM-Hyp. This was manifested as attenuated spontaneous osteo-commitment, increased susceptibility to osteo-induction, and a shift in the paracrine profile. It has been suggested that the ECM after physiological hypoxia is able to ensure the maintenance of a low-commitment state of MSCs. DcECM, which preserves the competence of the natural microenvironment of cells and is capable of “educating” others, appears to be a prospective tool for guiding cell modifications for cell therapy and tissue engineering. Full article

Animal-derived xenogeneic biomaterials utilized in different surgeries are promising for various applications in tissue engineering. However, tissue decellularization is necessary to attain a bioactive extracellular matrix (ECM) that can be safely transplanted. The main objective of the present study is to assess the structural integrity, biocompatibility, and potential use of various acellular biomaterials for tissue engineering applications. Hence, a bovine pericardium (BP), porcine pericardium (PP), and porcine tunica vaginalis (PTV) were decellularized using a Trypsin, Triton X (TX), and sodium dodecyl sulfate (SDS) (Trypsin + TX + SDS) protocol. The results reveal effective elimination of the cellular antigens with preservation of the ECM integrity confirmed via staining and electron microscopy. The elasticity of the decellularized PP (DPP) was markedly (p < 0.0001) increased. The tensile strength of DBP, and DPP was not affected after decellularization. All decellularized tissues were biocompatible with persistent growth of the adipose stem cells over 30 days. The staining confirmed cell adherence either to the peripheries of the materials or within their matrices. Moreover, the in vivo investigation confirmed the biocompatibility and degradability of the decellularized scaffolds. Conclusively, Trypsin + TX + SDS is a successful new protocol for tissue decellularization. Moreover, decellularized pericardia and tunica vaginalis are promising scaffolds for the engineering of different tissues with higher potential for the use of DPP in cardiovascular applications and DBP and DPTV in the reconstruction of higher-stress-bearing abdominal walls. Full article

Background: The decellularized adipose-derived matrix (DAM) has emerged as a promising biomaterial for inducing adipose tissue regeneration. Various methods have been employed to produce DAM, among which the enzyme-free method is a relatively recent preparation technique. The mechanical fragmentation step plays a crucial role in determining the efficacy of the enzyme-free preparation. Methods: The adipose tissue underwent fragmentation through the application of ultrasonication, homogenization, and freeze ball milling. This study compared the central temperature of the mixture immediately following crushing, the quantity of oil obtained after centrifugation, and the thickness of the middle layer. Fluorescence staining was utilized to compare the residual cell activity of the broken fat in the middle layer, while electron microscopy was employed to assess the integrity and properties of the adipocytes among the three methods. The primary products obtained through the three methods were subsequently subjected to processing using the enzyme-free method DAM. The assessment of degreasing and denucleation of DAM was conducted through HE staining, oil red staining, and determination of DNA residues. Subsequently, the ultrasonication-DAM (U-DAM) and homogenation-DAM (H-DAM) were implanted bilaterally on the back of immunocompromised mice, and a comparative analysis of their adipogenic and angiogenic effects in vivo was performed. Results: Oil discharge following ultrasonication and homogenization was significantly higher compared to that observed after freeze ball milling (p < 0.001), despite the latter exhibiting the lowest center temperature (p < 0.001). The middle layer was found to be thinnest after ultrasonication (p < 0.001), and most of the remaining cells were observed to be dead following fragmentation. Except for DAM obtained through freeze ball milling, DAM obtained through ultrasonication and homogenization could be completely denucleated and degreased. In the in vivo experiment, the first adipocytes were observed in U-DAM as early as 1 week after implantation, but not in H-DAM. After 8 weeks, a significant number of adipocytes were regenerated in both groups, but the U-DAM group demonstrated a more efficient adipose regeneration than in H-DAM (p = 0.0057). Conclusions: Ultrasonication and homogenization are effective mechanical fragmentation methods for breaking down adipocytes at the initial stage, enabling the production of DAM through an enzyme-free method that facilitates successful regeneration of adipose tissues in vivo. Furthermore, the enzyme-free method, which is based on the ultrasonication pre-fragmentation approach, exhibits superior performance in terms of denucleation, degreasing, and the removal of non-adipocyte matrix components, thereby resulting in the highest in vivo adipogenic induction efficiency. Full article

Finding an ideal scaffold is always an important issue in the field of cartilage tissue engineering. Both decellularized extracellular matrix and silk fibroin have been used as natural biomaterials for tissue regeneration. In this study, a secondary crosslinking method of γ irradiation and ethanol induction was used to prepare decellularized cartilage extracellular matrix and silk fibroin (dECM-SF) hydrogels with biological activity. Furthermore, the dECM-SF hydrogels were cast in custom-designed molds to produce a three-dimensional multi-channeled structure to improve internal connectivity. The adipose-derived stromal cells (ADSC) were seeded on the scaffolds, cultured in vitro for 2 weeks, and implanted in vivo for another 4 and 12 weeks. The double crosslinked dECM-SF hydrogels exhibited an excellent pore structure after lyophilization. The multi-channeled hydrogel scaffold presents higher water absorption ability, surface wettability, and no cytotoxicity. The addition of dECM and a channeled structure could promote chondrogenic differentiation of ADSC and engineered cartilage formation, confirmed by H&E, safranin O staining, type II collagen immunostaining, and qPCR assay. In conclusion, the hydrogel scaffold fabricated by the secondary crosslinking method has good plasticity and can be used as a scaffold for cartilage tissue engineering. The multi-channeled dECM-SF hydrogel scaffolds possess a chondrogenic induction activity that promotes engineered cartilage regeneration of ADSC in vivo. Full article

In recent decades, adipose tissue transplantation has become an essential treatment modality for tissue (volume) restoration and regeneration. The regenerative application of adipose tissue has only recently proven its usefulness; for example, the method is useful in reducing dermal scarring and accelerating skin-wound healing. The therapeutic effect is ascribed to the tissue stromal vascular fraction (tSVF) in adipose tissue. This consists of stromal cells, the trophic factors they secrete and the extracellular matrix (ECM), which have immune-modulating, pro-angiogenic and anti-fibrotic properties. This concise review focused on dermal regeneration using the following adipose-tissue components: adipose-tissue-derived stromal cells (ASCs), their secreted trophic factors (ASCs secretome), and the ECM. The opportunities of using a therapeutically functional scaffold, composed of a decellularized ECM hydrogel loaded with trophic factors of ASCs, to enhance wound healing are explored as well. An ECM-based hydrogel loaded with trophic factors combines all regenerative components of adipose tissue, while averting the possible disadvantages of the therapeutic use of adipose tissue, e.g., the necessity of liposuction procedures with a (small) risk of complications, the impossibility of interpatient use, and the limited storage options. Full article

Lymphedema causes tissue swelling due to the accumulation of lymphatic fluid in the tissue, which delays the process of wound-healing. Developing effective treatment options of lymphedema is still an urgent issue. In this study, we aim to fabricate tissue-engineered moist wound dressings with adipose stem cells (ASCs) and decellularized Wharton’s jelly (dWJ) from the human umbilical cord in order to ameliorate lymphedema. Rat ASCs were proliferated and an apparent layer was observed on dWJ at day 7 and 14. A rat tail lymphedema model was developed to evaluate the efficacy of the treatment. Approximately 1 cm of skin near the base of the rat tail was circularly excised. The wounds were treated by secondary healing (control) (n = 5), decellularized Wharton’s jelly (n = 5) and ASC-seeded dWJ (n = 5). The wound-healing rate and the tail volume were recorded once a week from week one to week five. Angiogenesis and lymphangiogenesis were assessed by immunochemistry staining with anti-CD31 and anti-LYVE1. The results showed that the wound-healing rate was faster and the tail volume was lesser in the ASC-seeded dWJ group than in the control group. More CD31+ and LYVE-1+ cells were observed at the wound-healing area in the ASC-seeded dWJ group than in the control group. This proves that tissue-engineered moist wound dressings can accelerate wound-healing and reduce lymphedema by promoting angiogenesis and lymphangiogenesis. Full article

A significant lack of donor organs restricts the opportunity to obtain tissue-specific scaffolds for tissue-engineering technologies. One of the acceptable solutions is the development of decellularization protocols for a human donor pancreas unsuitable for transplantation. A protocol of obtaining a biocompatible tissue-specific scaffold from decellularized fragments with pronounced human pancreas lipomatosis signs with preserved basic fibrillary proteins of a pancreatic tissue extracellular matrix was developed. The scaffold supports the adhesion and proliferation of human adipose derived stem cell (hADSCs) and prolongs the viability and insulin-producing function of pancreatic islets. Experiments conducted allow for the reliance on the prospects of using the donor pancreas unsuitable for transplantation in the technologies of tissue engineering and regenerative medicine, including the development of a tissue equivalent of a pancreas. Full article

Angiogenesis plays an important role in the development of bone and bone regeneration to provide the required molecules. Mesenchymal stem cells (MSCs) are pluripotent, self-renewing, and spindle-shaped cells, which can differentiate into multiple lineages such as chondrocytes, osteocytes, and adipocytes. MSCs derived from bone marrow (BMMSCs), adipose tissue (ADMSCs), and Wharton’s jelly (UCMSCs) are popular in the field of tissue regeneration. MSCs have been proposed that can promote bone regeneration by enhancing vascularization. In this study, the angiogenic potential of secretomes of undifferentiated and osteo-differentiated BMMSCs, ADMSCs, and UCMSCs seeded on human decellularized allogeneic bone were compared. Human umbilical vein endothelial cells (HUVECs) were treated with MSC secretomes. Cell growth, cell migration, and angiogenesis of HUVECs were analyzed by MTT, wound healing, and tube formation assays. Angiogenic gene expression levels of MSCs were evaluated using real-time quantitative PCR. Antibody neutralization was performed to validate the candidate target. Our study demonstrates that the angiogenic gene expression profile is tissue-dependent and the angiogenic ability of secretomes is independent of the state of differentiation. We also explore that IL-1b is important for MSC angiogenic potential. Taken together, this study proves that IL-1b in the secretomes plays a vital role in angiogenesis. Full article