Utilization of a Decellularized Skin Scaffold for Repair of a Cleft Palate in a Dog: A Case Report.

Cleft palates are oral deformities that mostly affect puppies. They are frequently extensive and characterized by bone and palatal mucosa malformation. This deformity is a serious condition that may result in the death of the dog, therefore surgical treatment is recommended. Tissue bioengineering has emerged as a valuable option to treat cleft palates by applying acellular biological scaffolds as grafts. This case report proposed a new approach for surgical correction of canine cleft palate through a grafting technique using a decellularized scaffold. A decellularized portion of skin was implanted to correct a large cleft palate in a 3-month-old female Pug dog. The skin fragment was obtained from a dog cadaver and a decellularization protocol was performed. Under general anesthesia, a bilateral mucoperiosteal separation of the entire length of cleft margins was performed, and the scaffold was then positioned between the tissue and the bone palate. The interaction of the grafted scaffold with the oral mucosa and palatine layers resulted in total cleft closure, without postsurgical rejection or infection, indicating the applicability of this technique in dog's cleft palate correction. This is the first reported case demonstrating this new technique, which resulted in full cleft closure and healing.

An extracellular matrix hydrogel from porcine urinary bladder for tissue engineering: In vitro and in vivo analyses.

BACKGROUND: The necessity to manufacture scaffolds with superior capabilities of biocompatibility and biodegradability has led to the production of extracellular matrix (ECM) scaffolds. Among their advantages, they allow better cell colonization, which enables its successful integration into the hosted tissue, surrounding the area to be repaired and their formulations facilitate placing it into irregular shapes. The ECM from porcine urinary bladder (pUBM) comprises proteins, proteoglycans and glycosaminoglycans which provide support and enable signals to the cells. These properties make it an excellent option to produce hydrogels that can be used in regenerative medicine. OBJECTIVE: The goal of this study was to assess the biocompatibility of an ECM hydrogel derived from the porcine urinary bladder (pUBMh) in vitro using fibroblasts, macrophages, and adipose-derived mesenchymal stem cells (AD-MCSs), as well as biocompatibility in vivo using Wistar rats. METHODS: Effects upon cells proliferation/viability was measured using MTT assay, cytotoxic effects were analyzed by quantifying lactate dehydrogenase release and the Live/Dead Cell Imaging assay. Macrophage activation was assessed by quantification of IL-6, IL-10, IL-12p70, MCP-1, and TNF-α using a microsphere-based cytometric bead array. For in vivo analysis, Wistar rats were inoculated into the dorsal sub-dermis with pUBMh. The specimens were sacrificed at 24 h after inoculation for histological study. RESULTS: The pUBMh obtained showed good consistency and absence of cell debris. The biocompatibility tests in vitro revealed that the pUBMh promoted cell proliferation and it is not cytotoxic on the three tested cell lines and induces the production of pro-inflammatory cytokines on macrophages, mainly TNF-α and MCP-1. In vivo, pUBMh exhibited fibroblast-like cell recruitment, without tissue damage or inflammation. CONCLUSION: The results show that pUBMh allows cell proliferation without cytotoxic effects and can be considered an excellent biomaterial for tissue engineering.

Cell Therapy and Tissue Engineering Approaches for Cartilage Repair and/or Regeneration.

Articular cartilage injuries caused by traumatic, mechanical and/or by progressive degeneration result in pain, swelling, subsequent loss of joint function and finally osteoarthritis. Due to the peculiar structure of the tissue (no blood supply), chondrocytes, the unique cellular phenotype in cartilage, receive their nutrition through diffusion from the synovial fluid and this limits their intrinsic capacity for healing. The first cellular avenue explored for cartilage repair involved the in situ transplantation of isolated chondrocytes. Latterly, an improved alternative for the above reparative strategy involved the infusion of mesenchymal stem cells (MSC), which in addition to a self-renewal capacity exhibit a differentiation potential to chondrocytes, as well as a capability to produce a vast array of growth factors, cytokines and extracellular matrix compounds involved in cartilage development. In addition to the above and foremost reparative options up till now in use, other therapeutic options have been developed, comprising the design of biomaterial substrates (scaffolds) capable of sustaining MSC attachment, proliferation and differentiation. The implantation of these engineered platforms, closely to the site of cartilage damage, may well facilitate the initiation of an 'in situ' cartilage reparation process. In this mini-review, we examined the timely and conceptual development of several cell-based methods, designed to repair/regenerate a damaged cartilage. In addition to the above described cartilage reparative options, other therapeutic alternatives still in progress are portrayed.