Bioscaffold-mediated mucosal remodeling following short-segment colonic mucosal resection

Preparation and Use of Decellularized Extracellular Matrix for Tissue Engineering

The multidisciplinary fields of tissue engineering and regenerative medicine have the potential to revolutionize the practise of medicine through the abilities to repair, regenerate, or replace tissues and organs with functional engineered constructs. To this end, tissue engineering combines scaffolding materials with cells and biologically active molecules into constructs with the appropriate structures and properties for tissue/organ regeneration, where scaffolding materials and biomolecules are the keys to mimic the native extracellular matrix (ECM). For this, one emerging way is to decellularize the native ECM into the materials suitable for, directly or in combination with other materials, creating functional constructs. Over the past decade, decellularized ECM (or dECM) has greatly facilitated the advance of tissue engineering and regenerative medicine, while being challenged in many ways. This article reviews the recent development of dECM for tissue engineering and regenerative medicine, with a focus on the preparation of dECM along with its influence on cell culture, the modification of dECM for use as a scaffolding material, and the novel techniques and emerging trends in processing dECM into functional constructs. We highlight the success of dECM and constructs in the in vitro, in vivo, and clinical applications and further identify the key issues and challenges involved, along with a discussion of future research directions.

A Comparison of Sterilization Techniques for Production of Decellularized Intestine in Mice

Tissue-engineered small intestinal implants are being widely investigated as a potential treatment for children with short bowel syndrome, yet are currently limited by their growth potential and relatively low surface area. To address this gap in the field, several investigators have utilized whole organ decellularization of the small intestine as a platform for subsequent growth of intestinal tissue. However, such scaffold-cell constructs require sterilization as a prerequisite for implantation, and the effects of the different pathogen-clearance techniques used on the tissue architecture remains unknown. The effects of four different published protocols for pathogen clearance of decellularized intestine, namely 0.1% peracetic acid (PAA), 0.18% PAA +4.8% ethanol (EtOH), 0.08% PAA +1% hydrogen peroxide (H₂O₂), and ultraviolet (UV) sterilization were compared using qualitative and quantitative techniques to assess changes to the extracellular matrix, cytocompatibility, and biocompatibility. All methods of sterilization of decellularized intestine were found to be equally effective and each method had similar histologic and scanning electron microscopy appearance of the sterilized tissue. In addition, collagen and glycosaminoglycan quantities, and the ability to support cell growth were similar among all methods. This study provides insights into the change in crypt villous architecture of the extracellular matrix with all sterilization techniques studied. Our findings demonstrate that sterilization affects the microarchitecture significantly, which has not been well accounted for in studies to date, and we were unable to identify a single best agent to achieve tissue sterilization while preserving the microarchitectural features of the tissue.

Scarring vs. functional healing: Matrix-based strategies to regulate tissue repair

All vertebrates possess mechanisms to restore damaged tissues with outcomes ranging from regeneration to scarring. Unfortunately, the mammalian response to tissue injury most often culminates in scar formation. Accounting for nearly 45% of deaths in the developed world, fibrosis is a process that stands diametrically opposed to functional tissue regeneration. Strategies to improve wound healing outcomes therefore require methods to limit fibrosis. Wound healing is guided by precise spatiotemporal deposition and remodelling of the extracellular matrix (ECM). The ECM, comprising the non-cellular component of tissues, is a signalling depot that is differentially regulated in scarring and regenerative healing. This Review focuses on the importance of the native matrix components during mammalian wound healing alongside a comparison to scar-free healing and then presents an overview of matrix-based strategies that attempt to exploit the role of the ECM to improve wound healing outcomes.