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Decellularization is regarded as a xenogenic antigen-reduction technique because it effectively eliminates all cellular and nuclear components while mitigating any negative impact on the composition, biological functionality, and structural integrity of the remaining extracellular matrix. This study aimed to histologically evaluate native, freeze dried and chemically decellularized bovine pericardium membrane. Also, this study focused on preservation of extracellular matrix after decellularization. Bovine pericardium membrane was decellularized by freeze thaw cycle followed by freeze drying and 1% sodium dodecyl sulphate. Unprocessed pericardium was used as control. The effectiveness of Decellularization was assessed based on the reduction of histologically visible nuclei. Decellularization by freeze thaw cycle followed by freeze drying resulted in 17.84% reduction in nuclei content and decellularization by sodium dodecyl sulphate results in 92% reduction in nuclei content compare to control group. Picrosirius red staining for freeze dried group displayed loosely organised, thin collagen bundles that exhibit reddish-yellow birefringence and sodium dodecyl sulfate group revealed dense collagen bundles that are parallelly organised and compact, exhibiting reddish-yellow birefringence and showed good structural integrity. These results suggested that the sodium do decyl sulfate showed optimal decellularization results with better extracellular matrix preservation. It may be a suitable protocol for producing a suitable scaffold for periodontal tissue regeneration. [ABSTRACT FROM AUTHOR]

Tissue engineering is a set of techniques for producing or reconstructing tissue that primarily aims to restore or improve the function of tissues in the human body. The aim of the present study was to evaluate the mechanical and histological characteristics of decellularized tracheal scaffolds prepared in comparison with fresh trachea for use in tracheal repair. In order to prepare the scaffold, sheep's trachea was prepared and after cleaning the waste tissues, they were decellularized. Then decellularized scaffolds were evaluated histologically and laboratory and numerical study of the nonlinear mechanical behavior of tracheal tissue and scaffold and their comparison. Examining the results of histological evaluations showed that the decellularization of the scaffolds was completely done. These results were confirmed by hematoxylin–eosin staining. Also, the exact hyperelastic properties of tracheal tissue and scaffold were used in biomechanical models, and according to the presented results, the five-term Mooney–Rivlin strain energy density function became a suitable behavioral model for modeling the hyperelastic behavior of trachea and scaffold. In total, the results of this research showed that the scaffolds obtained from decellularization by preserving the main compositions of the desired tissue can be a suitable platform for investigating cell behaviors. [ABSTRACT FROM AUTHOR]

Severe injuries to skeletal muscles, including cases of volumetric muscle loss (VML), are linked to substantial tissue damage, resulting in functional impairment and lasting disability. While skeletal muscle can regenerate following minor damage, extensive tissue loss in VML disrupts the natural regenerative capacity of the affected muscle tissue. Existing clinical approaches for VML, such as soft-tissue reconstruction and advanced bracing methods, need to be revised to restore tissue function and are associated with limitations in tissue availability and donor-site complications. Advancements in tissue engineering (TE), particularly in scaffold design and the delivery of cells and growth factors, show promising potential for regenerating damaged skeletal muscle tissue and restoring function. This article provides a brief overview of the pathophysiology of VML and critiques the shortcomings of current treatments. The subsequent section focuses on the criteria for designing TE scaffolds, offering insights into various natural and synthetic biomaterials and cell types for effectively regenerating skeletal muscle. We also review multiple TE strategies involving both acellular and cellular scaffolds to encourage the development and maturation of muscle tissue and facilitate integration, vascularization, and innervation. Finally, the article explores technical challenges hindering successful translation into clinical applications. [ABSTRACT FROM AUTHOR]

Previous studies showed that the bladder extracellular matrix (B‐ECM) could increase the differentiation efficiency of mesenchymal cells into smooth muscle cells (SMC). This study investigates the potential of human amniotic membrane‐derived hydrogel (HAM‐hydrogel) as an alternative to xenogeneic B‐ECM for the myogenic differentiation of the rabbit adipose tissue‐derived MSC (AD‐MSC). Decellularized human amniotic membrane (HAM) and sheep urinary bladder (SUB) were utilized to create pre‐gel solutions for hydrogel formation. Rabbit AD‐MSCs were cultured on SUB‐hydrogel or HAM‐hydrogel‐coated plates supplemented with differentiation media containing myogenic growth factors (PDGF‐BB and TGF‐β1). An uncoated plate served as the control. After 2 weeks, real‐time qPCR, immunocytochemistry, flow cytometry, and western blot were employed to assess the expression of SMC‐specific markers (MHC and α‐SMA) at both protein and mRNA levels. Our decellularization protocol efficiently removed cell nuclei from the bladder and amniotic tissues, preserving key ECM components (collagen, mucopolysaccharides, and elastin) within the hydrogels. Compared to the control, the hydrogel‐coated groups exhibited significantly upregulated expression of SMC markers (p ≤.05). These findings suggest HAM‐hydrogel as a promising xenogeneic‐free alternative for bladder tissue engineering, potentially overcoming limitations associated with ethical concerns and contamination risks of xenogeneic materials. [ABSTRACT FROM AUTHOR]

AbstractDecellularized tissue hydrogels, especially that mimic the native tissue, have a high potential for tissue engineering, three-dimensional (3D) cell culture, bioprinting, and therapeutic agent encapsulation due to their excellent biocompatibility and ability to facilitate the growth of cells. It is important to note that the decellularization process significantly affects the structural integrity and properties of the extracellular matrix, which in turn shapes the characteristics of the resulting hydrogels at the macromolecular level. Therefore, our study aims to identify an effective chemical decellularization method for sheep lung tissue, using a mixing/agitation technique with a range of detergents, including commonly [Sodium dodecyl sulfate (SDS), Triton X-100, and 3-((3-cholamidopropyl) dimethylammonio)-1-propanesulfonate] (CHAPS), and rarely used (sodium cholate hydrate, NP-40, and 3-[N,N-Dimethyl(3-myristoylaminopropyl)ammonio]propanesulfonate) (ASB-14). After the effectiveness of the used detergents on decellularization was determined by histological and biochemical methods, lung derived decellularized extracellular matrix was converted into hydrogel. We investigated the interactions between lung cells and decellularized extracellular matrix using proliferation assay, scanning electron microscopy, and immunofluorescence microscopy methods on BEAS-2B cells in air-liquid interface. Notably, this study emphasizes the effectiveness of ASB-14 in the decellularization process, showcasing its crucial role in removing cellular components while preserving vital extracellular matrix biological macromolecules, including glycosaminoglycans, collagen, and elastin. The resulting hydrogels demonstrated favorable mechanical properties and are compatible with both cell-cell and cell-extracellular matrix interactions. [ABSTRACT FROM AUTHOR]

Pediatric surgeons have faced esophageal reconstruction challenges for decades owing to a variety of congenital and acquired conditions. This work aimed to introduce a reproducible and efficient approach for creating tissue-engineered esophageal tissue using bone marrow mesenchymal stem cells (BMSCs) cultured in preconditioned mediums seeded on a sheep decellularized tunica vaginalis (DTV) scaffold for partial reconstruction of a rabbit's esophagus. DTV was performed using SDS and Triton X-100 solutions. The decellularized grafts were employed alone (DTV group) or after recellularization with BMSCs cultured for 10 days in preconditioned mediums (RTV group) for reconstructing a 3 cm segmental defect in the cervical esophagus of rabbits (n = 20) after the decellularization process was confirmed. Rabbits were observed for one month, after which they were euthanized, and the reconstructed esophagi were harvested for histological analysis. Six rabbits in the DTV group and eight rabbits in the RTV group survived until the end of the one-month study period. Despite histological examination demonstrating that both grafts completely repaired the esophageal defect, the RTV graft demonstrated a histological structure similar to that of the normal esophagus. The reconstructed esophagi in the RTV group revealed the arrangement of the different layers of the esophageal wall with the formation of newly formed blood vessels and Schwann-like cells. DTV xenograft is a novel scaffold that promotes cell adhesion and differentiation and might be effectively utilized for regenerating esophageal tissue, paving the way for future clinical trials in pediatric patients. [ABSTRACT FROM AUTHOR]

Decellularization of plant tissues is an emerging route to fabricate scaffolds for tissue engineering and regenerative medicine. Although significant progress has been made in the field of plant tissue decellularization, functionalization of plant scaffolds is still an emerging field, and loading them with L-ascorbic acid to promote skin regeneration has not yet been reported. L-ascorbic acid is an antioxidant that plays a key role in collagen synthesis as a cofactor of lysyl hydroxylase and prolyl hydroxylase. It has been shown to have significant importance in physiological wound healing by stimulating fibroblasts to produce collagen at both the molecular and the genetic levels. In this work, we aimed to fabricate an ascorbic acid-releasing bioactive scaffold by introducing a stable form of ascorbic acid, L-ascorbic acid 2-phosphate (AA2P), into decellularized baby spinach leaves and investigated its biological activity in vitro. Our results demonstrated that AA2P could be easily introduced into decellularized baby spinach leaf scaffolds and subsequently released within the effective dose range. AA2P-releasing baby spinach leaves were found to increase metabolic activity and enhance collagen synthesis in L929 fibroblasts after 21 days. In conclusion, this study demonstrated the fabrication of a novel functionalized skin tissue engineering scaffold and made a significant contribution to the fields of plant decellularization and skin tissue engineering. [ABSTRACT FROM AUTHOR]

The umbilical cord is a material that enhances regeneration and is devoid of age-related changes in the extracellular matrix (ECM). The aim of this work was to develop a biodegradable scaffold from a decellularized human umbilical cord (UC-scaffold) to heal full-thickness wounds. Decellularization was performed with 0.05% sodium dodecyl sulfate solution. The UC-scaffold was studied using morphological analysis methods. The composition of the UC-scaffold was studied using immunoblotting and Fourier transform infrared spectroscopy. The adhesion and proliferation of mesenchymal stromal cells were investigated using the LIVE/DEAD assay. The local reaction was determined by subcutaneous implantation in mice (n = 60). A model of a full-thickness skin wound in mice (n = 64) was used to assess the biological activity of the UC-scaffold. The proposed decellularization method showed its effectiveness in the umbilical cord, as it removed cells and retained a porous structure, type I and type IV collagen, TGF-β3, VEGF, and fibronectin in the ECM. The biodegradation of the UC-scaffold in the presence of collagenase, its stability during incubation in hyaluronidase solution, and its ability to swell by 1617 ± 120% were demonstrated. Subcutaneous scaffold implantation in mice showed gradual resorption of the product in vivo without the formation of a dense connective tissue capsule. Epithelialization of the wound occurred completely in contrast to the controls. All of these data suggest a potential for the use of the UC-scaffold. [ABSTRACT FROM AUTHOR]

The uterine tube extracellular matrix is a key component that regulates tubal tissue physiology, and it has a region-specific structural distribution, which is directly associated to its functions. Considering this, the application of biological matrices in culture systems is an interesting strategy to develop biomimetic tubal microenvironments and enhance their complexity. However, there are no established protocols to produce tubal biological matrices that consider the organ morphophysiology for such applications. Therefore, this study aimed to establish region-specific protocols to obtain decellularized scaffolds derived from porcine infundibulum, ampulla, and isthmus to provide suitable sources of biomaterials for tissue-engineering approaches. Porcine uterine tubes were decellularized in solutions of 0.1% SDS and 0.5% Triton X-100. The decellularization efficiency was evaluated by DAPI staining and DNA quantification. We analyzed the ECM composition and structure by optical and scanning electronic microscopy, FTIR, and Raman spectroscopy. DNA and DAPI assays validated the decellularization, presenting a significative reduction in cellular content. Structural and spectroscopy analyses revealed that the produced scaffolds remained well structured and with the ECM composition preserved. YS and HEK293 cells were used to attest cytocompatibility, allowing high cell viability rates and successful interaction with the scaffolds. These results suggest that such matrices are applicable for future biotechnological approaches in the reproductive field. [ABSTRACT FROM AUTHOR]

Background: Large and complex defects requiring reconstruction are challenging for orthopaedic surgeons. The use of human acellular dermal (HAD) matrices to augment large soft tissue defects such as those seen in massive rotator cuff tears, knee extensor mechanism failures and neglected Tendo-Achilles tears has proven to be a valuable tool in surgeons reconstructive armamentarium. Different methods for allograft decellularization and preservation alter the native properties of the scaffold. Traditional processing and preservation methods have shown to have drawbacks that preclude its widespread use. Some of the common issues include inferior biomechanical properties, the risk of rejection, limited customization, difficulty in storing and transporting, the requirement of pre-operative preparation, and last but not the least increased cost. Methods: We describe a novel processing and preservation method utilizing a two-step non-denaturing decellularization method coupled with preservation using a water-sequestering agent (glycerol) to remove immunogenic components while retaining biomechanical properties. The efficiency of this novel process was compared with the traditional freeze-drying method and verified by histological evaluation and biomechanical strength analysis. Results: The absence of cellular components and matrix integrity in hematoxylin and eosin-stained glycerol-preserved HAD (gly-HAD) samples compared to freeze-dried HAD (FD-HAD) demonstrated effective yet gentle decellularization. Biomechanical strength analysis revealed that gly-HADs are stronger with an ultimate tensile load to the failure strength of 210 N compared to FD-HAD (124N). The gly-HADs were found to have an optimal suture–retention strength of 126 N. Finally, sterility testing of the resultant grafts was checked to ensure a sterility assurance level of 10−6 to establish implantability. Conclusion: The novel processing and preservation technique is described in this paper to create a Human Acellular Dermis with higher biomechanical strength and superior histological characteristics. The processing and preservation technique ensured high sterility assurance levels to establish implantability. [ABSTRACT FROM AUTHOR]

Small-diameter vascular grafts (SDVGs) are severely lacking in clinical settings. Therefore, our study investigates a new source of biological vessels—bovine and porcine decellularized intercostal arteries (DIAs)—as potential SDVGs. We utilized a combination of SDS and Triton X-100 to perfuse the DIAs, establishing two different time protocols. The results show that perfusing with 1% concentrations of each decellularizing agent for 48 h yields DIAs with excellent biocompatibility and mechanical properties. The porcine decellularized intercostal arteries (PDIAs) we obtained had a length of approximately 14 cm and a diameter of about 1.5 mm, while the bovine decellularized intercostal arteries (BDIAs) were about 29 cm long with a diameter of approximately 2.2 mm. Although the lengths and diameters of both the PDIAs and BDIAs are suited for coronary artery bypass grafting (CABG), as the typical diameter of autologous arteries used in CABG is about 2 mm and the grafts required are at least 10 cm long, our research indicates that BDIAs possess more ideal mechanical characteristics for CABG than PDIAs, showing significant potential. Further enhancements may be necessary to address their limited hemocompatibility. [ABSTRACT FROM AUTHOR]

The gross morphological examination of native caprine heart valves revealed distinctive structural characteristics of the caprine's cardiac anatomy. Four primary orifices were identified, each protected by thin, valve‐like structures. Atrioventricular orifices featured tricuspid and bicuspid valves, while the aorta and pulmonary arteries were guarded by semilunar valves. Within the atrioventricular apparatus, distinct features were observed including the tricuspid valve's three leaflets and the bicuspid valve's anterior and posterior leaflets. Ultrasonography provided insights into valve thickness and chordae tendineae lengths. Morphometric studies compared leaflets/cusps within individual native valves, showcasing significant variations in dimensions. Comparative analysis between native and decellularized valves highlighted the effects of decellularization on leaflet thickness and chordae tendineae lengths. Decellularized valves exhibited reduced dimensions compared to native valves, indicating successful removal of cellular components. While some dimensions remained unchanged post‐decellularization, significant reductions were observed in leaflet thicknesses and chordae tendineae lengths. Notably, semilunar valve cusps displayed varying responses to decellularization, with significant reductions in cusp lengths observed in the aortic valve, while the pulmonary valve exhibited more subtle changes. These findings underscore the importance of understanding structural alterations in heart valves post‐decellularization, providing valuable insights for tissue engineering applications and regenerative medicine. [ABSTRACT FROM AUTHOR]

Heart valve replacement surgeries are performed on patients suffering from abnormal heart valve function. In these operations, the problematic tissue is replaced with mechanical valves or with bioprosthetics that are being developed. The thrombotic effect of mechanical valves, reflecting the need for lifelong use of anticoagulation drugs, and the short‐lived nature of biological valves make these two types of valves problematic. In addition, they cannot adapt to the somatic growth of young patients. Although decellularized scaffolds have shown some promise, a successful translation has so far evaded. Although decellularized porcine xenografts have been extensively studied in the literature, they have several disadvantages, such as a propensity for calcification in the implant model, a risk of porcine endogenous retrovirus (PERV) infection, and a high xenoantigen density. As seen in clinical data, it is clear that there are biocompatibility problems in almost all studies. However, since decellularized sheep heart valves have not been tried in the clinic, a large data pool could not be established. This review compares and contrasts decellularized porcine and sheep xenografts for heart valve tissue engineering. It reveals that decellularized sheep heart valves can be an alternative to pigs in terms of biocompatibility. In addition, it highlights the potential advantages of bioinks derived from the decellularized extracellular matrix in 3D bioprinting technology, emphasizing that they can be a new alternative for the application. We also outline the future prospects of using sheep xenografts for heart valve tissue engineering. [ABSTRACT FROM AUTHOR]

The paper highlights how significant characteristics of liver can be modeled in tissue-engineered constructs using unconventional scaffolds. Hepatic lobular organization and metabolic zonation can be mimicked with decellularized plant structures with vasculature resembling a native-hepatic lobule vascular arrangement or silk blend scaffolds meticulously designed for guided cellular arrangement as hepatic patches or metabolic activities. The functionality of hepatocytes can be enhanced and maintained for long periods in naturally fibrous structures paving way for bioartificial liver development. The phase I enzymatic activity in hepatic models can be raised exploiting the microfibrillar structure of paper to allow cellular stacking creating hypoxic conditions to induce in vivo-like xenobiotic metabolism. Lastly, the paper introduces amalgamation of carbon-based nanomaterials into existing scaffolds in liver tissue engineering. Plain Language Summary Unconventional scaffolds have the potential to meet the current challenges in liver tissue engineering- loss of hepatic morphology and functions over long-term culture, absence of native-like cell-cell and cell-matrix interactions, organization of hepatocytes into lobular structures exhibiting metabolic variations-which hinder pharmaceutical analysis, regenerative therapies and artificial organ development. Paper with cellulose microfibril network develops cellular aggregates with hypoxic conditions that influence enzymes of xenobiotic metabolism proving to be a better scaffold for hepatotoxicity testing compared with conventional monolayers in tissue culture plates. Decellularized plant stems provide already-built vasculature to be exploited for the development of intricate vessel networks that exist in hepatic lobules aiding in regenerative medicine for hepatic pathologies. Fibrous plant structures are excellent materials for the immobilization of hepatocytes and improve albumin secretion enabling their use in bioartificial liver development. Biomimicry of metabolic zonation in hepatic lobules can be achieved with perfusion culture using silk blend scaffolds with varying proportions of the liver matrix that orchestrate cellular function. The mechanical properties of silk allow the fabrication of structures that resemble liver anatomy to generate native-like hepatic lobules. Nanomaterials have immense potential as a component of composite material development for scaffolds to achieve improved predictive ability in pharmacokinetics. Most of these unconventional scaffolds have the added advantage of being readily available, accessible, affordable and sustainable for liver tissue engineering applications. Conclusively, the shift of attention away from conventional scaffolds poses a promising future in the field of tissue engineering. Graphical Abstract Article highlights Limitations of 2D culture: Current 2D culture practices cannot achieve the complexity of hepatic tissue including metabolic zonation, lobular organization, extensive vasculature, existence of multiple cell types. Splenic scaffold: Spleen proves to be the excellent choice of decellularized organ for liver tissue regeneration, however, this cross-organ recellularization procedure is not ideal for clinical translation. Plant-based scaffold: Selecting plant material that matches hepatic tissue mechanical properties and anatomical features including the channel arrangements (central vein and portal triad) help hepatic regeneration and pathological modeling. Naturally fibrous plant materials have the potential to be excellent platforms for bioartificial liver development based on high hepatocyte adherence and function. Paper-based scaffold: Hepatocyte culture on functionalized filter paper forms a physiologically more relevant model for hepatotoxicity assessment particularly because of higher activity of drug metabolizing enzymes. Silk-based scaffold: Hepatic lobular organization that supports metabolic zonation can be mimicked by varying ECM content in silk blend scaffolds to create native-like oxygen and nutrient gradient. CNT-based scaffold: Exceptional properties of carbon nanotubes make them ideal to mimic liver ECM allowing formation of hepatic spheroids with in vivo like characteristics- bile canaliculi, polarity and drug clearance. [ABSTRACT FROM AUTHOR]

The degeneration of intervertebral disc (IVD) is a disease of the entire joint between two vertebrae in the spine caused by loss of extracellular matrix (ECM) integrity, to date with no cure. The various regenerative approaches proposed so far have led to very limited successes. An emerging opportunity arises from the use of decellularized ECM as a scaffolding material that, directly or in combination with other materials, has greatly facilitated the advancement of tissue engineering. Here we focused on the decellularized matrix obtained from human umbilical cord Wharton's jelly (DWJ) which retains several structural and bioactive molecules very similar to those of the IVD ECM. However, being a viscous gel, DWJ has limited ability to retain ordered structural features when considered as architecture scaffold. To overcome this limitation, we produced DWJ‐based multifunctional hydrogels, in the form of 3D millicylinders containing different percentages of alginate, a seaweed‐derived polysaccharide, and gelatin, denatured collagen, which may impart mechanical integrity to the biologically active DWJ. The developed protocol, based on a freezing step, leads to the consolidation of the entire polymeric dispersion mixture, followed by an ionic gelation step and a freeze‐drying process. Finally, a porous, stable, easily storable, and suitable matrix for ex vivo experiments was obtained. The properties of the millicylinders (Wharton's jelly millicylinders [WJMs]) were then tested in culture of degenerated IVD cells isolated from disc tissues of patients undergoing surgical discectomy. We found that WJMs with the highest percentage of DWJ were effective in supporting cell migration, restoration of the IVD phenotype (increased expression of Collagen type 2, aggrecan, Sox9 and FOXO3a), anti‐inflammatory action, and stem cell activity of resident progenitor/notochordal cells (increased number of CD24 positive cells). We are confident that the DWJ‐based formulations proposed here can provide adequate stimuli to the cells present in the degenerated IVD to restart the anabolic machinery. [ABSTRACT FROM AUTHOR]

The recellularization of tissues after decellularization is a relatively new technology in the field of tissue engineering (TE). Decellularization involves removing cells from a tissue or organ, leaving only the extracellular matrix (ECM). This can then be recellularized with new cells to create functional tissues or organs. The first significant mention of recellularization in decellularized tissues can be traced to research conducted in the early 2000s. One of the landmark studies in this field was published in 2008 by Ott, where researchers demonstrated the recellularization of a decellularized rat heart with cardiac cells, resulting in a functional organ capable of contraction. Since then, other important studies have been published. These studies paved the way for the widespread application of recellularization in TE, demonstrating the potential of decellularized ECM to serve as a scaffold for regenerating functional tissues. Thus, although the concept of recellularization was initially explored in previous decades, these studies from the 2000s marked a major turning point in the development and practical application of the technology for the recellularization of decellularized tissues. The article reviews the historical advances and limitations in organ recellularization in TE over the last two decades.

Peripheral nerve regeneration after injury is still a clinical problem. The application of autologous nerve grafting, the gold standard treatment, is greatly restricted. Acellular nerve allografts (ANAs) are considered promising alternatives, but they are difficult to achieve satisfactory therapeutic outcomes, which may be attributed to their compact inherent ultrastructure and substantial loss of extracellular matrix (ECM) components. Regarding these deficiencies, this study developed an optimized multichannel ANA by a modified decellularization method. These innovative ANAs were demonstrated to retain more ECM bioactive molecules and regenerative factors, with effective elimination of cellular antigens. The presence of microchannels with larger pore size allowed ANAs to gain higher porosity and better swelling performance, which improves their internal ultrastructure. Their mechanical properties were more similar to those of native nerves. Moreover, the optimized ANAs exhibited good biocompatibility and possessed significant advantages in supporting the proliferation and migration of Schwann cells in vitro. The in vivo results further confirmed their superior capacity to promote axon regrowth and myelination as well as restore innervation of target muscles, leading to better functional recovery than the conventional ANAs. Overall, this study demonstrates that the optimized multichannel ANAs have great potential for clinical application and offer new insight into the further improvement of ANAs.

AbstractDecellularization is a process to harvest the decellularized extra cellular matrix (dECM) that helps develop 3D scaffolds which mimic the native tissue composition. The decellularized tissues retain the structural and functional properties of the extracellular matrix (ECM) by an efficient decellularization process that retains tissue-specific biochemical and biophysical cues for tissue regeneration. In this study, we report an injection-based decellularization method, without perfusion setup. This study also compares the efficiency of the proposed protocol in the two animal models viz rat and mice. This method harvests rat and mice liver dECM using ethylenediamine tetra acetic acid (EDTA) and sodium dodecyl sulphate (SDS) within 08 h and 02 h respectively and preserved significant amount of ECM proteins. We reported that the harvested mice decellularized extracellular matrix (mdECM) and rat decellularized extracellular matrix (rdECM) had significant reduction in their DNA content (∼97%) and retained structural architecture resembling their native tissue counterparts. The total protein content retained in mdECM was ∼39% while that retained in rdECM was ∼65%. It was also found that the sGAG (sulphated glycosaminoglycan) content showed a no List of Figures.

Liver transplantation represents the only definitive treatment for patients with end-stage liver disease. However, the shortage of liver donors provokes a dramatic gap between available grafts and patients on the waiting list. Whole liver bioengineering, an emerging field of tissue engineering, holds great potential to overcome this gap. This approach involves two main steps; the first is liver decellularization and the second is recellularization. Liver decellularization aims to remove cellular and nuclear materials from the organ, leaving behind extracellular matrices containing different structural proteins and growth factors while retaining both the vascular and biliary networks. Recellularization involves repopulating the decellularized liver with appropriate cells, theoretically from the recipient patient, to reconstruct the parenchyma, vascular tree, and biliary network. The aim of this review is to identify the major advances in decellularization and recellularization strategies and investigate obstacles for the clinical application of bioengineered liver, including immunogenicity of the designed liver extracellular matrices, the need for standardization of scaffold fabrication techniques, selection of suitable cell sources for parenchymal repopulation, vascular, and biliary tree reconstruction. In vivo transplantation models are also summarized for evaluating the functionality of bioengineered livers. Finally, the regulatory measures and future directions for confirming the safety and efficacy of bioengineered liver are also discussed. Addressing these challenges in whole liver bioengineering may offer new solutions to meet the demand for liver transplantation and improve patient outcomes.

BACKGROUND: Tissue engineering has brought new hope to the clinical challenge of liver failure, and the preparation of plant-derived decellularized fiber scaffolds holds significant importance in liver tissue engineering. OBJECTIVE: To prepare apple tissue decellularized scaffold material by using fresh apple slices and a solution of sodium dodecyl sulfate, and assess its biocompatibility. METHODS: Fresh apples were subjected to decellularization using phosphate buffer saline and sodium dodecyl sulfate solution, separately. Afterwards, the decellularized apple tissues and apple decellularized scaffold materials were decontaminated with phosphate buffer saline. Subsequently, scanning electron microscopy was used to assess the effectiveness of decellularization of the apple materials. Adipose-derived mesenchymal stem cells were extracted from the inguinal fat BALB/C of mice, and their expression of stem cell-related markers (CD45, CD34, CD73, CD90, and CD105) was identified through flow cytometry. The cells were then divided into a scaffold-free control group and a scaffold group. Equal amounts of adipose-derived mesenchymal stem cells were seeded onto both groups. The biocompatibility of the decellularized scaffold with adipose-derived mesenchymal stem cells was evaluated using CCK-8 assay, hematoxylineosin staining, and phalloidine staining. Cell adhesion and growth on the scaffold were observed under light microscopy and scanning electron microscopy. Furthermore, the scaffold was subdivided into the non-induced group and the hepatogenic-induced group. Adipose-derived mesenchymal stem cells were cultured on the decellularized apple scaffold, and they were cultured for 14 days in regular culture medium or hepatogenic induction medium for comparison. Immunofluorescent staining using liver cell markers, including albumin, cytokeratin 18, and CYP1A1, was performed. Enzyme-linked immunosorbent assay was used to detect the secretion of alpha fetoprotein and albumin. Additionally, scanning electron microscopy was employed to observe the morphology of the induced cells on the scaffold, verifying the expression of liver cell-related genes on the decellularized scaffold material. Finally, the cobalt-60 irradiated and sterilized decellularized apple scaffolds were transplanted onto the surface of mouse liver and the degradation of the scaffold was observed by gross observation and hematoxylin-eosin staining after 28 days. RESULTS AND CONCLUSION: (1) The scanning electron microscopy results revealed that the decellularized apple scaffold material retained a porous structure of approximately 100 μm in size, with no residual cells observed. (2) Through flow cytometry analysis, the cultured cells were identified as adipose-derived mesenchymal stem cells. (3) CCK-8 assay results demonstrated that the prepared decellularized apple tissue scaffold material exhibited no cytotoxicity. Hematoxylin-eosin staining and phalloidine staining showed that adipose-derived mesenchymal stem cells were capable of adhering and proliferating on the decellularized apple tissue scaffold. (4) The results obtained from immunofluorescence staining and enzyme-linked immunosorbent assay revealed that adipose-derived mesenchymal stem cells cultured on the decellularized apple scaffolds exhibited elevated expression of liver-specific proteins, including albumin, alpha-fetoprotein, cytokeratin 18, and CYP1A1. These results suggested that they were induced differentiation into hepatocyte-like cells possessing functional characteristics of liver cells. (5) The decellularized apple scaffold implanted at 7 days has integrated with the liver, with partial degradation of the scaffold observed. By 28 days, the decellularized apple scaffold has completely degraded and has been replaced by newly-formed tissue. (6) The results indicate that the decellularized scaffold material derived from apple tissue demonstrates favorable biocompatibility, promoting the proliferation, adhesion, and hepatic differentiation of adipose-derived mesenchymal stem cells. [ABSTRACT FROM AUTHOR]

Introduction: Terminal sterilization is important for the clinical applicability of decellularized xenografts. High hydrostatic pressurization (HHP) process is a potential strategy for decellularization and decontamination of xenografts; however, its disinfection efficiency remains poorly elucidated. This study investigated the disinfection efficacy of the HHP process at physiologically relevant 36 °C against difficult-to-kill spore-forming bacteria. Methods: Bacillus atrophaeus and Geobacillus stearothermophilus were suspended in a pressurization medium with or without antibiotic agents and pressurized under two different HHP procedures: repeated and sustained pressurization. Results: The sustained pressurizing conditions, exploited for the conventional tissue decellularization, did not effectively eliminate the bacteria; however, repeated pressurization greatly increased the disinfection effect. Moreover, the antibiotic-containing pressurization medium further increased the disinfection efficiency to the level required for sterilization. Conclusions: The optimized high hydrostatic pressurization can be used to sterilize biological tissues during the decellularization process and is a promising strategy for manufacturing tissue-derived healthcare products.

Abstract Background Uterus tissue engineering aims to repair a dysfunctional uterus that causes infertility, e.g., after significant scarring from benign or malign resection procedures. Decellularized uterine tissue provided regenerative support in several animal models as a biocompatible natural extracellular matrix (ECM) derived scaffold after uterine damage. However, variations in decellularization protocols and species used limit conclusive evidence and translational progress. Hence, a species-independent decellularization protocol could facilitate preclinical research. Therefore, we investigated if our developed sheep uterus decellularization protocol was species-independent and effective for the significantly larger bovine uterus. We further assessed if there were any negative post transplantation immunological consequences from the metalloproteinases 2 and 9 (MMP 2, MMP 9) treatment that was used as a preconditioning treatment to significantly improve scaffold recellularization after decellularization. Methods Bovine uterus was decellularized using sodium deoxycholate, and the remaining ECM was quantitatively assessed for DNA, protein, and ECM components. The morphology and physical attributes were examined by immunohistochemistry, electron microscopy, and mechanical tests. Scaffold biocompatibility, bioactivity, and angiogenic properties were assessed with the chorioallantoic membrane assay (CAM) and the immune response following transplantation of MMP treated scaffolds was compared with untreated scaffolds in a rat model. The in vitro recellularization efficiency of the scaffolds was also assessed. Results The decellularization protocol was effective for bovine uterus. The MMP treatment did not negatively affect scaffold immunogenicity in vivo, while the treatment potentiated mesenchymal stem cell recellularization in vitro. Furthermore, the decellularization protocol generated biocompatible and angiogenic uterine scaffolds. Conclusion Bovine uterus was successfully decellularized using previously established protocols. These results confirm earlier findings in the sheep model and further indicate that MMP treatment may be beneficial. The results further conclude the development of a species-independent, reproducible, and biocompatible scaffold generation protocol that can provide an important element for successful translational research.

Background: Osteochondral regeneration has long been recognized as a complex and challenging project in the field of tissue engineering. In particular, reconstructing the osteochondral interface is crucial for determining the effectiveness of the repair. Although several artificial layered or gradient scaffolds have been developed recently to simulate the natural interface, the functions of this unique structure have still not been fully replicated. In this paper, we utilized laser micro-patterning technology (LMPT) to modify the natural osteochondral “plugs” for use as grafts and aimed to directly apply the functional interface unit to repair osteochondral defects in a goat model. Methods: For in vitro evaluations, the optimal combination of LMPT parameters was confirmed through mechanical testing, finite element analysis, and comparing decellularization efficiency. The structural and biological properties of the laser micro-patterned osteochondral implants (LMP-OI) were verified by measuring the permeability of the interface and assessing the recellularization processes. In the goat model for osteochondral regeneration, a conical frustum-shaped defect was specifically created in the weight-bearing area of femoral condyles using a customized trephine with a variable diameter. This unreported defect shape enabled the implant to properly self-fix as expected. Results: The micro-patterning with the suitable pore density and morphology increased the permeability of the LMP-OIs, accelerated decellularization, maintained mechanical stability, and provided two relative independent microenvironments for subsequent recellularization. The LMP-OIs with goat's autologous bone marrow stromal cells in the cartilage layer have securely integrated into the osteochondral defects. At 6 and 12 months after implantation, both imaging and histological assessments showed a significant improvement in the healing of the cartilage and subchondral bone. Conclusion: With the natural interface unit and zonal recellularization, the LMP-OI is an ideal scaffold to repair osteochondral defects especially in large animals. The translational potential of this article: These findings suggest that such a modified xenogeneic osteochondral implant could potentially be explored in clinical translation for treatment of osteochondral injuries. Furthermore, trimming a conical frustum shape to the defect region, especially for large-sized defects, may be an effective way to achieve self-fixing for the implant.

Abstract Background Decellularized extracellular matrix (dECM) from several tissue sources has been proposed as a promising alternative to conventional scaffolds used in regenerative endodontic procedures (REPs). This systematic review aimed to evaluate the histological outcomes of studies utilizing dECM-derived scaffolds for REPs and to analyse the contributing factors that might influence the nature of regenerated tissues. Methods The PRISMA 2020 guidelines were used. A search of articles published until April 2024 was conducted in Google Scholar, Scopus, PubMed and Web of Science databases. Additional records were manually searched in major endodontic journals. Original articles including histological results of dECM in REPs and in-vivo studies were included while reviews, in-vitro studies and clinical trials were excluded. The quality assessment of the included studies was analysed using the ARRIVE guidelines. Risk of Bias assessment was done using the (SYRCLE) risk of bias tool. Results Out of the 387 studies obtained, 17 studies were included for analysis. In most studies, when used as scaffolds with or without exogenous cells, dECM showed the potential to enhance angiogenesis, dentinogenesis and to regenerate pulp-like and dentin-like tissues. However, the included studies showed heterogeneity of decellularization methods, animal models, scaffold source, form and delivery, as well as high risk of bias and average quality of evidence. Discussion Decellularized ECM-derived scaffolds could offer a potential off-the-shelf scaffold for dentin-pulp regeneration in REPs. However, due to the methodological heterogeneity and the average quality of the studies included in this review, the overall effectiveness of decellularized ECM-derived scaffolds is still unclear. More standardized preclinical research is needed as well as well-constructed clinical trials to prove the efficacy of these scaffolds for clinical translation. Other The protocol was registered in PROSPERO database #CRD42023433026. This review was funded by the Science, Technology and Innovation Funding Authority (STDF) under grant number (44426).

Abstract Whole lung engineering and the transplantation of its products is an ambitious goal and ultimately a viable solution for alleviating the donor-shortage crisis for lung transplants. There are several limitations currently impeding progress in the field with a major obstacle being efficient revascularization of decellularized scaffolds, which requires an extremely large number of cells when using larger pre-clinical animal models. Here, we developed a simple but effective experimental pulmonary bioengineering platform by utilizing the lung as a scaffold. Revascularization of pulmonary vasculature using human umbilical cord vein endothelial cells was feasible using a novel in-house developed perfusion-based bioreactor. The endothelial lumens formed in the peripheral alveolar area were confirmed using a transmission electron microscope. The quality of engineered lung vasculature was evaluated using box-counting analysis of histological images. The engineered mouse lungs were successfully transplanted into the orthotopic thoracic cavity. The engineered vasculature in the lung scaffold showed blood perfusion after transplantation without significant hemorrhage. The mouse-based lung bioengineering system can be utilized as an efficient ex-vivo screening platform for lung tissue engineering.

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Tissue regeneration is thought to have considerable promise with the use of scaffolds designed for tissue engineering. Although polymer-based scaffolds for tissue engineering have been used extensively and developed quickly, their ability to mimic the in-vivo milieu, overcome immunogenicity, and have comparable mechanical or biochemical properties has limited their capability for repair. Fortunately, there is a compelling method to get around these challenges thanks to the development of extracellular matrix (ECM) scaffolds made from decellularized tissues. We used ECM decellularized sheep kidney capsule tissue in our research. Using detergents such as Triton-X100 and sodium dodecyl sulfate (SDS), these scaffolds were decellularized. DNA content, histology, mechanical properties analysis, attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR), biocompatibility, hemocompatibility and scanning electron microscope (SEM) imaging were measured. The results showed that the three-dimensional (3D) structure of the ECM remained largely intact. The scaffolds mentioned above had several hydrophilic properties. The best biocompatibility and blood compatibility properties were reported in the SDS method of 0.5%. The best decellularization scaffold was introduced with 0.5% SDS. Therefore, it can be proposed as a scaffold that has ECM like natural tissue, for tissue engineering applications. [ABSTRACT FROM AUTHOR]

For decades, dermal tissue grafts have been used in various regenerative, reconstructive, and augmentative procedures across the body. To eliminate antigenicity and immunogenic response while still preserving the individual components and collective structural integrity of the extracellular matrix (ECM), dermis can be decellularized. Acellular dermal matrix (ADM) products like such are produced to accurately serve diverse clinical purposes. The aim of the present study is to evaluate the efficacy of a novel decellularization protocol of the human dermis, which eliminates residual human genetic material without compromising the biomechanical integrity and collagenous content of the tissue. Moreover, a freeze-drying protocol was validated. The results showed that though our decellularization protocol, human dermis can be decellularized obtaining a biocompatible matrix. The procedure is completely realized in GMP aseptic condition, avoiding tissue terminal sterilization. [ABSTRACT FROM AUTHOR]

Bone allografts are clinically used in a variety of surgical procedures, and tissue banks are responsible for harvesting, processing, quality testing, storing, and delivering these materials for transplantation. In tissue banks, the bone is processed for the removal of all organic content, remaining only the tissue structure (scaffold). However, several studies have shown that even after using different processing methods, viable cells, functional proteins, and DNA may still persist in the tissue, which constitute the main causes of graft rejection. Therefore, the objective of this study was to establish techniques and biological parameters for quality validation of allografts. To this end, we propose the use of 3 combined methods such as microscopy, histology, and molecular biology techniques to evaluate the quality of allografts harvested and processed by the Brazilian National Institute of Traumatology and Orthopedics (INTO) tissue bank according to the donation criteria of the Brazilian National Health Surveillance Agency and the Brazilian National Transplant System. Bone fragments from different processing stages showed no viable cells on histology, an intact extracellular matrix on scanning electron microscopy, and gradual reduction in DNA amount. Different techniques were used to demonstrate the quality of allografts produced by the INTO tissue bank and to establish biological parameters for ensuring the safety and quality of these products. Future studies need to be undertaken to assess and validate the efficacy of the decellularization process in larger bone grafts with diverse architectural configurations. [ABSTRACT FROM AUTHOR]

Pericardial patches are currently used as reconstructive material in cardiac surgery for surgical treatment of cardiac septal defects. Autologous pericardial patches, either treated with glutaraldehyde or not, can be used as an alternative to synthetic materials or xenograft in congenital septal defects repair. The availability of an allogenic decellularized pericardium could reduce complication during and after surgery and could be a valid alternative. Decellularization of allogenic tissues aims at reducing the immunogenic reaction that might trigger inflammation and tissue calcification over time. The ideal graft for congenital heart disease repair should be biocompatible, mechanically resistant, non-immunogenic, and should have the ability to growth with the patients. The aim of the present study is the evaluation of the efficacy of a new decellularization protocol of homologous pericardium, even after cryopreservation. The technique has proven to be suitable as a tissue bank procedure and highly successful in the removal of cells and nucleic acids content, but also in the preservation of collagen and biomechanical properties of the human pericardium. [ABSTRACT FROM AUTHOR]

Cardiovascular diseases are considered the leading cause of mortality globally; even with low mortality in dogs, such diseases are described in the same way in companion animals and humans. This study aimed to devise an effective decellularization protocol for the canine myocardium through the association of physical, chemical, and enzymatic methods, assessing resultant alterations in the myocardial extracellular matrix to obtain a suitable scaffold. Two canine hearts were collected; the samples were sectioned into ±1 cm2 fragments, washed in distilled water and 1× PBS solution, and followed by treatment under four distinct decellularization protocols. Sodium Dodecyl Sulfate (SDS) 1% 7 days + Triton X-100 1% for 48 h (Protocol I); Sodium Dodecyl Sulfate (SDS) 1% 5 days + Triton X-100 1% for 48 h (Protocol II); Trypsin 0.05% for 1 h at 36 °C + freezing −80 °C overnight + Sodium Dodecyl Sulfate (SDS) 1% for 3 days, Triton-X-100 for 48 h hours (Protocol III); 0.05% trypsin for 1 h at 36 °C + freezing at −80 °C overnight + 1% Sodium Dodecyl Sulfate (SDS) for 2 days + 1% Triton-X-100 for 24 h (Protocol IV). After analysis, Protocols I and II showed the removal of cellular content and preservation of extracellular matrix (ECM) contents, unlike Protocols III and IV, which retracted the ECM and removed essential elements of the matrix. In theory, although Protocols I and II have similar results, Protocol II stands out for the preservation of the architecture and components of the extracellular matrix, along with reduced exposure time to reagents, making it the recommended protocol for the development of a canine myocardial scaffold. [ABSTRACT FROM AUTHOR]

Regenerative medicine researchers are interested in extracellular matrix (ECM) investigations around fabricating scaffolds that mimic the biological environment. These structures can be utilized in different disease and drug screenings as three-dimensional (3D) models. This study aimed to decellularization of rat prostate by different methods to reach a suitable scaffold and introduce it in cancer studies. In this experimental study, rat prostates were decellularized by 1% sodium dodecyl sulfate (SDS) and 1% sodium deoxycholate (SD) methods. Decellularized prostate matrix (DPM) was stained using hematoxylin-eosin (H&E) and Masson's trichrome (MT) techniques to determine the presence of the nucleus and collagen. A scanning electron microscope (SEM) was used to examine the morphology and cell attachment to the DPM. By culturing LNcap cells on the DPM, recellularization was studied. Both decellularization methods (1% SDS and 1% SD) completely removed the cells from the DPM. The tissue structure has been significantly preserved, which is confirmed by the staining methods and SEM images. The preservation of a large amount of collagen content was established through MT staining and using the kit. Cell adhesion in the DPM was reported by SEM. No toxicity or hemolysis was observed in the DPM. Migration of cancer cells into the DPM was seen. Prostate decellularization with SDS and SD, in addition to cell removal, can maintain the ECM structure to a large extent without having cytotoxic and hemolysis effects. [ABSTRACT FROM AUTHOR]

The reconstruction of patients who possess multi morbid medical histories remains a challenge. With the ever-increasing number of patients with diabetes, infections, and trauma, there is a consistent need for promotion of soft tissue healing and a reliable substrate to assist with every aspect of soft tissue reconstruction, as well as the loss of fascial domain. Several proprietary products filled some of these needs but have failed to fulfill the needs of the clinician when faced with reconstructing multiple soft tissue systems, such as the integument and the musculoskeletal system. In this paper we discuss the use of decellularized human dermis (DermaPure®, Tissue Regenix, Universal City, TX, USA) through which a unique human tissue processing technique (dCELL® technology, Tissue Regenix, Universal City, TX, USA) and the creation of multiple product forms have proven to exhibit versatility in a wide range of clinical needs for successful soft tissue reconstruction. The background of human tissue processing, basic science, and early clinical studies are detailed, which has translated to the rationale for the success of this unique soft tissue substrate in orthoplastic reconstruction, which is also provided here in detail. [ABSTRACT FROM AUTHOR]

The regeneration of osteochondral lesions by tissue engineering techniques is challenging due to the lack of physicochemical characteristics and dual‐lineage (osteogenesis and chondrogenesis). A scaffold with better mechanical properties and dual lineage capability is required for the regeneration of osteochondral defects. In this study, a hydrogel prepared from decellularized human umbilical cord tissue was developed and evaluated for osteochondral regeneration. Mesenchymal stem cells (MSCs) isolated from the umbilical cord were seeded with hydrogel for 28 days, and cell‐hydrogel composites were cultured in basal and osteogenic media. Alizarin red staining, quantitative polymerase chain reaction, and immunofluorescent staining were used to confirm that the hydrogel was biocompatible and capable of inducing osteogenic differentiation in umbilical cord‐derived MSCs. The findings demonstrate that human MSCs differentiated into an osteogenic lineage following 28 days of cultivation in basal and osteoinductive media. The expression was higher in the cell‐hydrogel composites cultured in osteoinductive media, as evidenced by increased levels of messenger RNA and protein expression of osteogenic markers as compared to basal media cultured cell‐hydrogel composites. Additionally, calcium deposits were also observed, which provide additional evidence of osteogenic differentiation. The findings demonstrate that the hydrogel is biocompatible with MSCs and possesses osteoinductive capability in vitro. It may be potentially useful for osteochondral regeneration. [ABSTRACT FROM AUTHOR]

Kidney regeneration is hindered by the limited pool of intrinsic reparative cells. Advanced therapies targeting renal regeneration have the potential to alleviate the clinical and financial burdens associated with kidney disease. Delivery systems for cells, extracellular vesicles, or growth factors aimed at enhancing regeneration can benefit from vehicles enabling targeted delivery and controlled release. Hydrogels, optimized to carry biological cargo while promoting regeneration, have emerged as promising candidates for this purpose. This study aims to develop a hydrogel from decellularized kidney extracellular matrix (DKECM) and explore its biocompatibility as a biomaterial for renal regeneration. The resulting hydrogel crosslinks with temperature and exhibits a high concentration of extracellular matrix. The decellularization process efficiently removes detergent residues, yielding a pathogen-free biomaterial that is non-hemolytic and devoid of α-gal epitope. Upon interaction with macrophages, the hydrogel induces differentiation into both pro-inflammatory and anti-inflammatory phenotypes, suggesting an adequate balance to promote biomaterial functionality in vivo. Renal progenitor cells encapsulated in the DKECM hydrogel demonstrate higher viability and proliferation than in commercial collagen-I hydrogels, while also expressing tubular cells and podocyte markers in long-term culture. Overall, the injectable biomaterial derived from porcine DKECM is anticipated to elicit minimal host reaction while fostering progenitor cell bioactivity, offering a potential avenue for enhancing renal regeneration in clinical settings. The quest to improve treatments for kidney disease is crucial, given the challenges faced by patients on dialysis or waiting for transplants. Exciting new therapies combining biomaterials with cells can revolutionize kidney repair. In this study, researchers created a hydrogel from pig kidney. This gel could be used to deliver cells and other substances that help in kidney regeneration. Despite coming from pigs, it's safe for use in humans, with no harmful substances and reduced risk of immune reactions. Importantly, it promotes a balanced healing response in the body. This research not only advances our knowledge of kidney repair but also offers hope for more effective treatments for kidney diseases. [Display omitted] [ABSTRACT FROM AUTHOR]

The extracellular matrix (ECM) is a dynamic and complex network of proteins and molecules that surrounds cells and tissues in the nervous system and orchestrates a myriad of biological functions. This review carefully examines the diverse interactions between cells and the ECM, as well as the transformative chemical and physical changes that the ECM undergoes during neural development, aging, and disease. These transformations play a pivotal role in shaping tissue morphogenesis and neural activity, thereby influencing the functionality of the central nervous system (CNS). In our comprehensive review, we describe the diverse behaviors of the CNS ECM in different physiological and pathological scenarios and explore the unique properties that make ECM‐based strategies attractive for CNS repair and regeneration. Addressing the challenges of scalability, variability, and integration with host tissues, we review how advanced natural, synthetic, and combinatorial matrix approaches enhance biocompatibility, mechanical properties, and functional recovery. Overall, this review highlights the potential of decellularized ECM as a powerful tool for CNS modeling and regenerative purposes and sets the stage for future research in this exciting field. This article is categorized under:Implantable Materials and Surgical Technologies > Nanotechnology in Tissue Repair and ReplacementTherapeutic Approaches and Drug Discovery > Nanomedicine for Neurological DiseaseImplantable Materials and Surgical Technologies > Nanomaterials and Implants [ABSTRACT FROM AUTHOR]

Surgical treatment of tracheal diseases, trauma, and congenital stenosis has shown success through tracheal reconstruction coupled with palliative care. However, challenges in surgical-based tracheal repairs have prompted the exploration of alternative approaches for tracheal replacement. Tissue-based treatments, involving the cultivation of patient cells on a network of extracellular matrix (ECM) from donor tissue, hold promise for restoring tracheal structure and function without eliciting an immune reaction. In this study, we utilized decellularized canine tracheas as tissue models to develop two types of cell carriers: a decellularized scaffold and a hydrogel. Our hypothesis posits that both carriers, containing essential biochemical niches provided by ECM components, facilitate cell attachment without inducing cytotoxicity. Canine tracheas underwent vacuum-assisted decellularization (VAD), and the ECM-rich hydrogel was prepared through peptic digestion of the decellularized trachea. The decellularized canine trachea exhibited a significant reduction in DNA content and major histocompatibility complex class II, while preserving crucial ECM components such as collagen, glycosaminoglycan, laminin, and fibronectin. Scanning electron microscope and fluorescent microscope images revealed a fibrous ECM network on the luminal side of the cell-free trachea, supporting epithelial cell attachment. Moreover, the ECM-rich hydrogel exhibited excellent viability for human mesenchymal stem cells encapsulated for 3 days, indicating the potential of cell-laden hydrogel in promoting the development of cartilage rings of the trachea. This study underscores the versatility of the trachea in producing two distinct cell carriers—decellularized scaffold and hydrogel—both containing the native biochemical niche essential for tracheal tissue engineering applications. Canine tracheae were harvested and subjected to decellularization. The resulting decellularized tracheae were used to prepare two different cell-carrier systems: scaffold and hydrogel. The scaffold was utilized for seeding human bronchial airway epithelium cells (HBEpCs) on the luminal surface, while the hydrogel was used for encapsulating hMSCs and seeding human umbilical vein endothelial cells (HUVECs). The extracellular matrix-rich cell scaffolds provided a biological niche for re-epithelial lining. hMSCs and HUVECs showed remarkable viability in and on the hydrogel, respectively. However, the formation of capillary-like structures by HUVECs was not detected. [ABSTRACT FROM AUTHOR]