Decellularized human fetal intestine as a bioscaffold for regeneration of the rabbit bladder submucosa

Pericardial bioscaffold coated with ECM gels and urothelial cells for the repair of a rabbit urinary bladder defect

Repair of damaged or faulty complex modular organs such as the urinary bladder is a current clinical challenge. The design of constructs for reconstructive urological surgery can draw advantage from the bioactivity of natural extracellular matrix (ECM) bioscaffolds, as well as the activity provided by cells seeded into constructs. Considering these benefits, this work compares the performance of pericardial ECM bioscaffolds and constructs seeded with gel-supported urothelial cells in the repair of urinary bladder defects in rabbits. The bioscaffolds considered in this study are of porcine (pM) and bovine (bM) origin and exhibited a residual composition that confers bioactivity in mesh presentation. Coating an ECM gel on the bioscaffolds promoted the adhesion and viability of urothelial cells. Repairing a full-thickness urinary bladder defect in a rabbit model with the bioscaffolds and constructs resulted in the integration with the host bladder; meanwhile, bladder volumetric capacity was promoted using bM and constructs. Although no contribution of gel/cell seeding to the failure of mechanical properties of the urinary neobladder was observed, this seeding technique is suitable for integration with different strategies to engineer constructs for urinary bladder reconstructive surgery.

Perspectives on the extracellular matrix in inflammatory bowel disease and bowel decellularization protocols

The extracellular matrix (ECM) is a non-cellular three-dimensional structure present in all tissues that is essential for the intestinal maintenance, function and structure, as well as for providing physical support for tissue integrity and elasticity. ECM enables the regulation of various processes involved in tissue homeostasis, being vital for healing, growth, migration and cell differentiation. Structurally, ECM is composed of water, polysaccharides and proteins, such as collagen fibers and proteoglycans, which are specifically arranged for each tissue. In pathological scenarios, such as inflammatory bowel disease (IBD), the deposition and remodeling of the ECM can be altered in relation to the homeostatic composition. IBD, such as Ulcerative colitis and Crohn's disease, can be differentiated according to ECM alterations, such as circulating levels of collagen, laminin and vimentin neoepitopes. In this context, ECM presents particularities in both physiological and pathological processes, however, exploring methods of tissue decellularization is emerging as a promising frontier for new therapeutic interventions and clinical protocols, promoting the development of new approaches to intestinal diseases.

Decellularized small intestine scaffolds: a potential xenograft for restoration of intestinal perforation

Small intestine perforation is a serious medical condition that requires immediate medical attention. The traditional course of treatment entails resection followed by anastomosis; however, it has complications such as small bowel syndrome (SBS), anastomotic leakage, and fistula formation. Here, a novel strategy is demonstrated, that utilizes the xenogeneic, decellularized goat small intestine as a patch for small intestine regeneration in cases of intestinal perforation. The goat small intestine scaffold underwent sodium dodecyl sulfate decellularization, which revealed consistent, quick, and effective decellularization. Decellularization contributed the least amount of extracellular matrix degradation while maintaining the intestinal architecture. By implanting the decellularized goat small intestine scaffolds (DGSIS) on the chorioallantoic membrane (CAM), no discernible loss of angiogenesis was seen in the CAM region, and this enabled the DGSIS to be evaluated for biocompatibility in ovo. The DGSIS was then xeno-transplanted as a patch on a small intestine perforation rat model. After 30 days post transplant, barium salt used as contrast gastrointestinal X-ray imaging revealed no leakage or obstruction in the small intestine. Histology, scanning electron microscopy, and immunohistochemistry assisted in analyzing the engraftment of host cells into the xeno patch. The xeno-patch expressed high levels of E-cadherin, α-smooth muscle actin (α-SMA), Occludin, Zonnula occluden (ZO-1), Ki 67, and Na+/K+-ATPase. The xeno-patch was consequently recellularized and incorporated into the host without causing an inflammatory reaction. As an outcome, decellularized goat small intestine was employed as a xenograft and could be suitable for regeneration of the perforated small intestine.

The impact of matrix age on intervertebral disc regeneration

With the lack of effective treatments for low back pain, the use of extracellular matrix (ECM)-based biomaterials have emerged with undeniable promise for IVD regeneration. Decellularized scaffolds can recreate an ideal microenvironment inducing tissue remodeling and repair. In particular, fetal tissues have a superior regenerative capacity given their ECM composition. In line with this, we unraveled age-associated alterations of the nucleus pulposus (NP) matrisome. Thus, the aim of the present work was to evaluate the impact of ECM donor age on IVD de/regeneration. Accordingly, we optimized an SDS (0.1 %, 1 h)-based decellularization protocol that preserves ECM cues in bovine NPs from different ages. After repopulation with adult NP cells, younger matrices showed the highest repopulation efficiency. Most importantly, cells seeded on younger scaffolds produced healthy ECM proteins suggesting an increased capacity to restore a functional IVD microenvironment. In vivo, only fetal matrices decreased neovessel formation, showing an anti-angiogenic potential. Our findings demonstrate that ECM donor age has a strong influence on angiogenesis and ECM de novo synthesis, opening new avenues for novel therapeutic strategies for the IVD. Additionally, more appropriate 3D models to study age-associated IVD pathology were unveiled.

Augmentation cystoplasty in dogs: A comparative study of different tunica vaginalis grafts

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Tunica vaginalis allograft and sheep tunica vaginalis decellularized extracellular matrix successfully rebuilt the bladder wall with minor complications in dogs.

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Sheep tunica vaginalis xenograft has disappointing results in the canine model since the bladders became contracted with decreased capacity.

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Tunica vaginalis grafts represent a simple and low-cost choice for augmentation cystoplasty in dogs.

In veterinary practice, numerous urological disorders that cause bladder dysfunction necessitate augmentation cystoplasty (AC). The purpose of this study is to evaluate the dog tunica vaginalis allograft (DTVA), sheep tunica vaginalis xenograft (STVX) and sheep tunica vaginalis decellularized extracellular matrix (STVDEM) as graft materials for urinary bladder (UB) reconstruction following a 45±5% cystectomy model in dogs. In this study, 18 adult apparently healthy mongrel dogs of both sexes were divided into three groups (6 dogs each): the DTVA group, the STVX group, and the STVDEM group. The evaluation of the AC in different groups was carried out using clinical, hematological, serum biochemical, urine, ultrasonographic, retrograde positive cystogram, and histopathological analysis all over the study period of 12 weeks. The dogs in all groups survived the procedures, except three dogs died from both STVX and DTVA groups. The mean bladder capacity indicated that the DTVA and STVX groups had regained 82.22% and 68.62%, respectively, of their preoperative baseline capacity. Interestingly, the STVDEM group's bladder capacity increased to 113.70%. Although histological analysis revealed that the three grafts successfully rebuilt the bladder wall, the STVDEM demonstrated well-organized and well-differentiated epithelial and muscular tissues that resembled, but were not identical to, native UB tissues. As a result, STVDEM is proposed as an ideal and potential acellular graft for UB reconstruction in dogs, whereas DTVA and STVX could be employed in emergencies requiring UB reconstruction.

Applications of decellularized materials in tissue engineering: advantages, drawbacks and current improvements, and future perspectives

Decellularized materials (DMs) are attracting more and more attention because of their native structures, comparatively high bioactivity, low immunogenicity and good biodegradability, which are difficult to be imitated by synthetic materials. Recently, DMs have been demonstrated to possess great potential to overcome the disadvantages of autografts and have become a kind of promising material for tissue engineering. In this systematic review, we aimed to not only provide a quick access for understanding DMs, but also bring new ideas to utilize them more appropriately in tissue engineering. Firstly, the preparation of DMs was introduced. Then, the updated applications of DMs derived from different tissues and organs in tissue engineering were comprehensively summarized. In particular, their advantages, drawbacks and current improvements were emphasized. Moreover, we analyzed and proposed future perspectives.

Tissue-Specific Decellularization Methods: Rationale and Strategies to Achieve Regenerative Compounds

The extracellular matrix (ECM) is a complex network with multiple functions, including specific functions during tissue regeneration. Precisely, the properties of the ECM have been thoroughly used in tissue engineering and regenerative medicine research, aiming to restore the function of damaged or dysfunctional tissues. Tissue decellularization is gaining momentum as a technique to obtain potentially implantable decellularized extracellular matrix (dECM) with well-preserved key components. Interestingly, the tissue-specific dECM is becoming a feasible option to carry out regenerative medicine research, with multiple advantages compared to other approaches. This review provides an overview of the most common methods used to obtain the dECM and summarizes the strategies adopted to decellularize specific tissues, aiming to provide a helpful guide for future research development.

Identifying the Growth Factors for Improving Neointestinal Regeneration in Rats through Transcriptome Analysis Using RNA-Seq Data

Using our novel surgical model of simultaneous intestinal adaptation "A" and neointestinal regeneration "N" conditions in individual rats to determine feasibility for research and clinical application, we further utilized next generation RNA sequencing (RNA-Seq) here in normal control tissue and both conditions ("A" and "N") across time to decipher transcriptome changes in neoregeneration and adaptation of intestinal tissue at weeks 1, 4, and 12. We also performed bioinformatics analyses to identify key growth factors for improving intestinal adaptation and neointestinal regeneration. Our analyses indicate several interesting phenomena. First, Gene Ontology and pathway analyses indicate that cell cycle and DNA replication processes are enhanced in week 1 "A"; however, in week 1 "N", many immune-related processes are involved. Second, we found some growth factors upregulated or downregulated especially in week 1 "N" versus "A". Third, based on each condition and time point versus normal control tissue, we found in week 1 "N" BMP2, BMP3, and NTF3 are significantly and specifically downregulated, indicating that the regenerative process may be inhibited in the absence of these growth factors. This study reveals complex growth factor regulation in small neointestinal regeneration and intestinal adaptation and provides potential applications in tissue engineering by introducing key growth factors identified here into the injury site.

Tissue-Engineered Grafts from Human Decellularized Extracellular Matrices: A Systematic Review and Future Perspectives

Tissue engineering and regenerative medicine involve many different artificial and biologic materials, frequently integrated in composite scaffolds, which can be repopulated with various cell types. One of the most promising scaffolds is decellularized allogeneic extracellular matrix (ECM) then recellularized by autologous or stem cells, in order to develop fully personalized clinical approaches. Decellularization protocols have to efficiently remove immunogenic cellular materials, maintaining the nonimmunogenic ECM, which is endowed with specific inductive/differentiating actions due to its architecture and bioactive factors. In the present paper, we review the available literature about the development of grafts from decellularized human tissues/organs. Human tissues may be obtained not only from surgery but also from cadavers, suggesting possible development of Human Tissue BioBanks from body donation programs. Many human tissues/organs have been decellularized for tissue engineering purposes, such as cartilage, bone, skeletal muscle, tendons, adipose tissue, heart, vessels, lung, dental pulp, intestine, liver, pancreas, kidney, gonads, uterus, childbirth products, cornea, and peripheral nerves. In vitro recellularizations have been reported with various cell types and procedures (seeding, injection, and perfusion). Conversely, studies about in vivo behaviour are poorly represented. Actually, the future challenge will be the development of human grafts to be implanted fully restored in all their structural/functional aspects.