Comparison of acellular small intestinal matrix (ASIM) and 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide crosslinked ASIM (ASIM-EDC) for repair of full-thickness skin wounds in rabbits

Skin loss presents an ongoing challenge in reconstructive surgery. Approaches to achieve tension-free closure of these defects include autologous skin flaps, alloplastic and xenogenic implants. However, these approaches have disadvantages, including donor-site morbidity, infections and immunological rejections. Acellular tissue scaffolds have recently been suggested as a novel therapy for these defects. In this study, an acellular small intestinal matrix (ASIM) of bubaline origin was prepared using sodium deoxycholate. In order to reduce the immunogenicity, we crosslinked it using 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride (EDC). Healing potential of ASIM and ASIM-EDC was compared in full-thickness skin wounds in rabbits. Eighteen clinically healthy New Zealand white rabbits of either sex were randomly divided into three equal groups. Under anesthesia, four full-thickness skin wounds (20 mm × 20 mm each) were produced on the dorsum of each rabbit. Wounds in control (I) were left open whereas in ASIM (II) and ASIM-EDC (III) they were repaired with ASIM and ASIM-EDC, respectively. Planimetry, wound contracture, immunological and histological observations were carried out to evaluate healing process. Significantly (P < 0.05) lesser wound contraction was observed in ASIM (II) and ASIM-EDC (III) as compared to control (I). Total IgG response in sera was significantly (P < 0.05) lower over 60 days in ASIM-EDC (III) as compared to ASIM (II) as detected by ELISA. Stimulation index of peripheral blood lymphocyte was significantly (P < 0.05) lower over 42 days in ASIM-EDC (III) as compared to ASIM (II) by MTT assay. Histologically, improved epithelization, neovascularization, fibroplasia and best arranged collagen fibers were observed in ASIM-EDC (III) as early as on post-implantation day 21. These findings indicate that bubaline ASIM-EDC have potential for biomedical applications.