Effect of cell-free supernatant of Bifidobacterium bifidum combined with chitosan biodegradable film on full thickness wound healing in rats

Introduction: Wound healing is one of the most critical issues human has been faced since the beginning of creation. Biodegradable polymers are of particular importance. In this study, cell-free supernatant (CFS) of Bifidobacterium bifidum combined with chitosan (CH) film was evaluated as a wound dressing.Methods: Biodegradable films (CH and CFS/CH), as a novel wound dressing, were prepared. For the evaluation of dressing efficacy, 45 male Wistar rats weighing 200-250 g were randomly divided into 3 groups: negative control (without wound treatment), positive control (wound treatment by CH film), and probiotic (wound treatment by CFS/CH film). One full thickness wound was created on the dorsal area of the animals. The wound in positive control and probiotic groups were immediately covered by CH and CFS/CH dressing, respectively. Wound healing process was evaluated by macroscopic observation and histological analysis. During the treatment the expression of IL-1, TGF-B and IL-6 were assayed by qRT-PCR.Results: Our results showed different infiltration patterns of macrophages, fibroblasts, and neutrophils in CFS/CH treated group. Enhanced disposition of collagen and elastin caused improvement of wound healing process by the film. Based on the gene expression results, use of CFS/CH film caused improvement in wound healing kinetic.Conclusion: The biodegradable film based on chitosan and CFS of B. bifidum improves the wound healing process.