Morphological evaluation of polysaccharide content and collagen composition during cutaneous wound healing in the Sunda porcupine (Hystrix javanica)

Wound healing in the Sunda porcupine is believed to occur quickly, although the wound is large and severe. Wound enclosure involves many processes to restore the lost or damaged skin structure where conjugated polysaccharide-protein and collagen, as the main components deposited in wound tissue to restore it. The aim of this study was to evaluate alteration of polysaccharide contents and collagen in untreated full-thickness wound healing in the thoracodorsal and lumbosacral regions in the Sunda porcupines. Histological analysis was performed by periodic acid Schiff, alcian blue pH 2.5, picrosirius red staining method and Low Vacuum Scanning Electron Microscope (LV-SEM) imaging to obtain the fundamental data of healing process. Wound healing began with re-epithelization followed by progressive wound contraction with 4 overlapping stages in about 30–50 days until the wound closed (21–30 days in thoracodorsal and 30–50 days in lumbosacral). Neutral polysaccharide was more widely distributed compared to the acid polysaccharide in almost all stages of wound healing. The ratio of collagen I to III appeared to be higher in the thoracodorsal region than the lumbosacral region during healing process. LV-SEM imaging showed changes in connective tissue structure in the wound border and granulation tissue which appeared abundant and mixed of thin and thick fiber. In conclusion, cutaneous full thickness wound healing in the Sunda porcupine occurred faster in the thoracodorsal region, which might be correlated to the role of neutral polysaccharide and a high ratio of collagen I to III.