Search Results (54)

The rising prevalence of chronic kidney disease represents a major global health burden. Limitations of current renal replacement therapies, including donor organ shortages, rejection, and dialysis-related complications, underscore the need for innovative treatment options. This narrative review assesses the feasibility of bioengineered kidneys as an alternative to current treatments by discussing advances in decellularization, recellularization, and the transplantation of cell-on-scaffold kidneys. We propose that the development of functional bioengineered kidneys follows a hierarchical, staged process, in which vascular patency is the primary prerequisite for graft survival, followed by partial restoration of glomerular filtration, with complete tubular function remaining the final and most challenging milestone. Perfusion-based whole-organ decellularization has made significant progress in preserving the extracellular matrix, enabling the production of acellular human kidney scaffolds. However, complete recellularization of whole kidneys has not yet been achieved. Nevertheless, partially repopulated kidney scaffolds have been shown to withstand physiological blood pressure, produce urine, and exhibit filtration in large-animal models. Complete endothelial coverage of the vascular network proved essential for preventing thrombosis after transplantation. Current work on bioengineered kidneys shows promising results regarding feasibility for clinical application. It is important to note that most of the included studies are proof-of-concept, characterized by small sample sizes and short observation periods. Although these findings are crucial for further research, they cannot be generalized, and larger trials are recommended. In addition to cell-on-scaffold kidneys, 3D bioprinting is a promising technique that could eliminate the need for donor scaffolds. Full article

Organ failure remains one of the foremost medical and socioeconomic challenges of the twenty-first century, with global transplant waiting lists far exceeding the supply of donor organs. Chronic supportive therapies sustain life but do not restore organ function, underscoring an urgent need for curative alternatives. Bioartificial organs represent a major frontier in organ replacement, driven by converging advances in cell biology, biomaterials science, and bioengineering. By integrating living cells or biologically derived matrices with engineered devices or scaffolds, these systems aim to restore functions that purely mechanical supports cannot reproduce. This review examines the principal technological platforms underpinning the field, including cell encapsulation, decellularization and recellularization, three-dimensional bioprinting, organoids, organ-on-chip systems, and xenotransplantation, and discusses their application to kidney, liver, heart, pancreas, and lung replacement. Across organ systems, progress is advancing from experimental proof-of-concept toward modular and increasingly translational platforms, although whole-organ bioengineering remains largely preclinical for the most structurally complex targets. The major unresolved barriers include vascularization, immune compatibility, scalable cell manufacturing, durable function, and stable integration between biological and engineered components. Overall, bioartificial organ engineering is evolving toward clinically relevant therapeutic strategies capable of complementing, bridging, or eventually reducing dependence on donor-organ transplantation. Full article

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

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

Peripheral nerve injuries pose a significant clinical challenge due to the limited self-repair capacity and the complexity of neural tissue architecture. Tissue engineering strategies applied to the peripheral nerve system aim to restore functional nerve constructs by combining scaffolds, cells, and biochemical cues to recreate the native microenvironment. This work aimed to propose the electrical conductivity as a functional readout of structural and biological remodeling in engineered peripheral nerve scaffolds, along with functional and molecular evaluations. To this end, bioimpedance measurements were combined with equivalent circuit modeling to track state-dependent changes across different levels of tissue organization. Murine sciatic nerves were decellularized and recellularized with neural populations to generate engineered constructs, and their electrical properties were assessed using broadband bioimpedance spectroscopy. Distinct impedance profiles were observed across control, decellularized, and recellularized samples, reflecting structural and functional changes associated with cell removal and repopulation. Furthermore, a multilayer series RC circuit model was implemented to accurately reproduce the measured spectra, enabling the extraction of layer-specific electrical parameters. Analysis of these parameters revealed that decellularization reduces compartmental resistances and increases inter-layer coupling, whereas recellularization restores outer-layer resistances and reduces coupling, consistent with functional tissue organization. Overall, the results demonstrate that bioimpedance provides a readout of the scaffold biological state and cellular integration, and that equivalent circuit modeling offers a quantitative framework to link structural remodeling to electrical function in engineered peripheral nerve tissues. 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

The development of cardiovascular tissue engineering is a promising area of study in regenerative medicine, offering innovative solutions for restoring damaged cardiac structures. However, traditional methods face multiple limitations, including the complexity of scaffolds, optimal recellularization, and functional tissue maturation. At the same time, deep learning has demonstrated significant potential in biomedicine and is increasingly being explored to optimize processes. This review examines recent benefits in cardiovascular tissue engineering and the applicability of deep learning in this domain, highlighting the benefits of artificial intelligence (AI) algorithms in scaffold modeling, cellular interaction analysis, and tissue regeneration prediction. Additionally, we discuss major challenges in integrating AI, such as the lack of large, standardized datasets; the need for interpretable models for clinical use; and ethical and regulatory constraints. Despite these limitations, recent progress in AI and the availability of advanced machine learning techniques provide promising perspectives for transforming regenerative medicine. Future research should focus on improving access to relevant data, developing explainable AI models, and integrating these technologies into personalized medicine, ultimately accelerating the progression of cardiovascular tissue engineering from an experimental stage to clinical utilization. Full article

Background: Developing reliable and cost-effective decellularization methods is critical for advancing tissue engineering and regenerative medicine, particularly in regions with limited access to specialized perfusion systems. Methods: This study standardized a gravity-assisted perfusion protocol for rat liver decellularization, designed to operate without pumps or pressurized equipment. Adult Wistar rat livers were processed through a gravity-driven vascular flushing method and compared with a conventional immersion-based protocol. The resulting scaffolds were evaluated by macroscopic inspection, histological staining (Masson’s trichrome), and residual DNA quantification. Results: The gravity-assisted perfusion method achieved more efficient cellular removal and superior preservation of extracellular matrix (ECM) integrity compared with immersion. Residual DNA levels were 3.7 ng/mg in perfused samples, 209.47 ng/mg in immersed samples, and 331.97 ng/mg in controls, confirming a statistically significant reduction (p < 0.05). Only the perfused group met the accepted threshold for effective decellularization (<50 ng/mg dry tissue). Histological analysis corroborated these findings, showing the absence of nuclei and the preservation of collagen architecture characteristic of a structurally intact ECM. Conclusions: This low-cost, reproducible, and technically simple system enables the generation of high-quality acellular hepatic scaffolds without mechanical pumps. Its accessibility and scalability make it suitable for laboratories with limited infrastructure and educational settings. Moreover, this gravity-assisted approach provides a foundation for future recellularization and preclinical studies aimed at developing bioengineered liver constructs for regenerative and transplant applications. Full article

The reconstruction of the foreskin using autografts is a complex procedure. A novel decellularisation method for epithelial tissue has been developed, producing an extracellular matrix scaffold from human donor foreskin. This study evaluated the immune response and integration of this scaffold after implantation in rats, focusing on inflammatory infiltrate, neovascularization, recellularization, and foreign body reaction. Twenty-six rats underwent a 1 cm infrascapular incision with scaffold implantation in the hypodermal layer. Group A (13 rats) was subject to a 30-day follow-up period, while Group B (13 rats) was subject to a 5-day follow-up period. Inflammation at the implantation site was scored from 0 (none) to 3 (severe). Tissue explants were. After 5 days (Group B) and 30 days (Group A), a tissue explant was performed and examined histologically and immunohistochemically. The clinical evaluation revealed slight signs of inflammation during the initial five days following the implantation procedure. Neutrophil (0.87 ± 0.35; 1 ± 0.53) and eosinophil (0.61 ± 0.51; 0.75 ± 0.46) presence was slight, with no significant differences between groups. Lymphocyte infiltration was moderate (1.87 ± 0.35; 1.75 ± 0.46), exceeding macrophage presence (1.25 ± 0.46; 1.12 ± 0.35). Neovascularization and cellular colonization were significantly greater at 30 days (2 ± 0.53; 2.42 ± 0.53) compared to 5 days (0.57 ± 0.21; 0.62 ± 0.32). Encapsulation remained mild in all cases, with no intergroup differences (0.87 ± 0.35). These findings indicate that the decellularized extracellular matrix derived from human foreskin elicits minimal immune response while promoting neovascularization and cellular repopulation. This supports its potential use as a biocompatible scaffold in reconstructive procedures. Full article

The global need for tissue and organ transplantation paved the way for plant-based scaffolds as cheap, ethical, and valuable alternatives to synthetic and animal-derived matrices for tissue regeneration. Over the years, the field has outgrown its initial scope, including the development of tissue models, platforms for drug testing and delivery, biosensors, and laboratory-grown meat. In this scoping review, we aimed to shed light on the frequency of the use of different plant matrices, the main techniques for decellularization, the functionalization methods for stimulating mammalian cell attachment, and the main results. To that purpose, we searched the keywords “decellularized” AND “scaffold” AND (“plant” OR “vegetable”) in online-available databases (Science Direct, Scopus, PubMed, and Sage Journals). From the selection and study of 71 articles, we observed a multitude of plant sources and tissues, along with a large and inhomogeneous body of protocols used for decellularization, functionalization and recellularization of plant matrices, which all led to variable results, with different extents of success (mostly in vitro). Since the field of plant-based scaffolds shows high potential for growth in the next few years, driven by emerging biotechnological applications, we conclude that future research should focus on plant sources with low economic and environmental impacts while also pursuing the standardization of the methods involved and a much deeper characterization of the scaffold performance in vivo. Full article

Tracheal defects have been the focus of research since the 19th century, but reconstructing this complex structure remains challenging. Identifying a safe, effective tracheal substitute is a key goal of surgery. This integrative review explores current tracheal substitutes and tissue engineering techniques. Data were collected from June 2024 to March 2025 from electronically available databases. Articles published between 2015 and 2025 were selected using the individualized protocol for each database. After screening 190 articles, 82 were excluded, and 108 were reviewed, with 100 meeting the final inclusion criteria. Recent substitutes include three-dimensional synthetic grafts made from polycaprolactone and copolyamide with thermoplastic elastomer, thermoplastic polyurethane and polylactic acid. Additionally, models using decellularized and recellularized tracheal matrix scaffolds and bioprinting techniques are being developed. Comparative studies of synthetic grafts and tracheal scaffolds, as well as cell self-aggregation methods to create tracheal analogues, are discussed. Advances in hybrid approaches combining synthetic polymers with extracellular matrix components aim to improve biocompatibility and functional integration. The importance of selecting appropriate preclinical animal models, such as goats, is also highlighted for translational relevance. Further research is required to refine protocols, overcome challenges related to vascularization and immune response, and ensure the development of clinically viable, long-lasting tracheal substitutes. Full article

The mammary gland is a modified sweat gland responsible for milk production. It is affected by diseases that reduce animals’ quality of life, consequently leading to economic losses in livestock. With advancements in tissue bioengineering and regenerative medicine, studying the extracellular matrix (ECM) of the bovine mammary gland can improve our understanding of its physiology and the processes that affect it. This knowledge could also enable the development of sustainable therapeutic alternatives for both the dairy production chain and human oncology research. A common approach in regenerative medicine is decellularization, a process that removes all cells from tissue while preserving its architecture and ECM components for subsequent recellularization. The success of recellularization depends on obtaining immunologically compatible scaffolds and using appropriate cell culture sources and methods to ensure tissue functionality. However, tissue culture technology still faces challenges due to specific requirements and high costs. Here, we review the literature on biomaterials and tissue engineering, providing an overview of the ECM of the bovine mammary gland and advances in its bioengineering, with a focus on regenerative medicine for bovine species. The methodology employed consists of a structured search of scientific databases, including PubMed, Google Scholar, and SciELO, using specific keywords related to tissue engineering and the bovine mammary gland. The selection criteria prioritized peer-reviewed articles published between 2002 and 2025 that demonstrated scientific relevance and contributed to the understanding of bovine mammary gland bioengineering. Although research on this topic has advanced, vascularization, tissue maturation, and scalability remain key barriers to widespread application and economic viability. Full article

Vascularized composite allotransplantation (VCA) has emerged as a robust alternative for addressing anatomically complex defects but requires a toxic lifelong immunosuppressive regimen. Tissue engineering offers the promise of creating recipient-specific alternative grafts using a decellularization and recellularization approach. In this article, we establish a reliable protocol for human face decellularization by immersion as a new tool in the development of engineered graft alternatives for reconstructive surgery. Three cadaveric face grafts were immersed in 1% sodium dodecyl sulfate for 216 h followed by 1% Triton X-100 for 48 h, without perfusion through the pedicle. We determined that decellularization was successfully accomplished for three facial specimens as confirmed by histological evaluation and quantification of DNA content. The extracellular components including collagen, glycosaminoglycans, elastin, and matrix-bound growth factors were preserved. Vascular architecture did not show significant differences between native and decellularized grafts as imaged by X-ray angiography. The mechanical strength of the grafts was not altered after decellularization. We also showed that the decellularized grafts were biocompatible in vitro and in vivo allowing cell engraftment. As a result, we have successfully developed a protocol to yield a clinical size decellularized graft suitable for generating a recellularized, potentially non-immunogenic graft for facial reconstruction. Full article

The field of reconstructive surgery faces significant challenges in addressing limb loss and disfigurement, with current organ preservation methods limited by short storage times. Decellularization offers a promising solution for generating engineered alternatives for reconstructive surgery by removing cellular material while preserving the extracellular matrix (ECM) and providing scaffolds for tissue regeneration. In this study, we developed a robust protocol for decellularizing whole digits from long-term freezer storage, achieving the successful removal of cellular material with intact ECM. Digit angiography confirmed the preservation of vascular integrity, facilitating future perfusion for recellularization. Quantitative analysis revealed significantly lower DNA content in decellularized tissues, indicating effective decellularization. Furthermore, extracellular matrix analysis showed the preservation of collagen, elastin, and glycosaminoglycans (GAGs) contents. Histological examination confirmed the reduction in cellularity and maintenance of tissue architecture in decellularized digits. Mechanical strength testing of decellularized digit tendons proved consistent with that of native digits. Our findings highlight the potential of decellularized digits as versatile platforms for tissue engineering and regenerative medicine. Moving forward, further optimization of protocols and collaborative efforts are essential for translating these findings into clinical practice, offering innovative solutions for reconstructive surgery and limb transplantation. Full article

Vascular graft failure rates remain unacceptably high due to thrombosis and poor integration, necessitating innovative solutions. This study optimized plant-derived extracellular matrix scaffolds as a scalable and biocompatible alternative to synthetic grafts and autologous vessels. We refined decellularization protocols to achieve >95% DNA removal while preserving mechanical properties comparable to native vessels, significantly enhancing endothelial cell seeding. Leatherleaf viburnum leaves were decellularized using sodium dodecyl sulfate-based and Trypsin/Tergitol-based treatments, achieved via clearing in bleach and Triton X-100 for 6 to 72 h. To assess the environmental influence on scaffold performance, leaves from multiple collection sites were processed using sodium dodecyl sulfate-based protocols. Scaffold performance was evaluated through tensile testing and histological analysis to assess structural integrity, while DNA quantification and endothelial cell recellularization measured biological compatibility. Sodium dodecyl sulfate-treated scaffolds with shorter clearing durations demonstrated the highest DNA removal (≥95%) while preserving mechanical properties, significantly outperforming Trypsin/Tergitol treatments. Longer clearing times reduced fiber diameter by 60%, compromising scaffold strength. Shorter clearing times preserved extracellular matrix integrity and significantly improved endothelial cell seeding efficiency. Larger leaves supported significantly higher endothelial cell densities than smaller leaves, highlighting the need for standardized material sources. Permeability tests demonstrated minimal leakage at 120 mmHg and structural stability under dynamic flow conditions, suggesting their suitability for vascular applications. These findings establish a reliable framework for optimizing plant-derived grafts, improving their reproducibility and performance for tissue engineering applications. Full article