Evaluation of biocompatibility and angiogenic potential of extracellular matrix hydrogel biofunctionalized with the LL-37 peptide.

BACKGROUND: Biomaterials must allow revascularization for a successful tissue regeneration process. Biomaterials formulated from the extracellular matrix (ECM) have gained popularity in tissue engineering because of their superior biocompatibility, and due to their rheological properties, ECM-hydrogels can be easily applied in damaged areas, allowing cell colonization and integration into the host tissue. Porcine urinary bladder ECM (pUBM) retains functional signaling and structural proteins, being an excellent option in regenerative medicine. Even some small molecules, such as the antimicrobial cathelicidin-derived LL-37 peptide have proven angiogenic properties. OBJECTIVE: The objective of this study was to evaluate the biocompatibility and angiogenic potential of an ECM-hydrogel derived from the porcine urinary bladder (pUBMh) biofunctionalized with the LL-37 peptide (pUBMh/LL37). METHODS: Macrophages, fibroblasts, and adipose tissue-derived mesenchymal stem cells (AD-MSC) were exposed pUBMh/LL37, and the effect on cell proliferation was evaluated by MTT assay, cytotoxicity by quantification of lactate dehydrogenase release and the Live/Dead Cell Imaging assays. Moreover, macrophage production of IL-6, IL-10, IL-12p70, MCP-1, INF-γ, and TNF-α cytokines was quantified using a bead-based cytometric array. pUBMh/LL37 was implanted directly by dorsal subcutaneous injection in Wistar rats for 24 h to evaluate biocompatibility, and pUBMh/LL37-loaded angioreactors were implanted for 21 days for evaluation of angiogenesis. RESULTS: We found that pUBMh/LL37 did not affect cell proliferation and is cytocompatible to all tested cell lines but induces the production of TNF-α and MCP-1 in macrophages. In vivo, this ECM-hydrogel induces fibroblast-like cell recruitment within the material, without tissue damage or inflammation at 48 h. Interestingly, tissue remodeling with vasculature inside angioreactors was seen at 21 days. CONCLUSIONS: Our results showed that pUBMh/LL37 is cytologically compatible, and induces angiogenesis in vivo, showing potential for tissue regeneration therapies.

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.

Utility of decellularised urinary bladder extracellular matrix in full mucosalisation of a post-oncological maxillectomy defect.

This report highlights the utility of MatriStem Surgical Matrix Thick UBM™ (rebranded as Gentrix® ACell, Inc), a decellularised urinary bladder extracellular matrix in the reconstruction of a post-oncological maxillectomy defect. In utilising this biological construct to serve as a biological dressing, our patient underwent complete mucosalisation of his surgical site without the development of an oroantral fistula and with adequate maxillary vestibule to allow for definitive oral rehabilitation with a removable partial denture.

Outcomes of Dog Bite Avulsion Injury Reconstruction With Urinary Bladder Matrix.

Dog bite avulsion injuries of the head and neck are difficult to manage in pediatric patients. This study assesses the outcomes of using porcine urinary bladder extracellular matrix (UBM) for reconstruction of these complete avulsion injuries. Five male pediatric patients underwent reconstruction using UBM. Two (40%) patients underwent reconstruction of the nose; the other 3 patients underwent reconstruction of the forehead, forehead/glabella, and auricle. The average size of the avulsion defect was 7.0 ± 2.4 cm2. No patient developed wound dehiscence, graft loss, or wound infection. Four (80%) patients received pulsed dye laser treatment to improve wound cosmesis. Use of UBM is a safe and effective reconstructive option after dog bite avulsion injuries of the head and neck. Given the advantages of convenient availability and avoidance of donor site morbidity, UBM can be considered for reconstruction of posttraumatic avulsion injuries or Mohs defects.

Porcine Urinary Bladder Extracellular Matrix for the Salvage of Fibula Free Flap Skin Paddle: Technical Note and Description of a Case.

This report establishes a novel application of a commercially available porcine urinary bladder extracellular matrix, MatriStem (ACell, Inc., Columbia, MD), in the salvage of partial loss of the skin paddle of a fibula osteoseptocutaneous free flap that was utilized for mandibular reconstruction.