Impaired wound healing is a major medical challenge, especially in diabetics. Over the centuries, the main goal of tissue engineering and regenerative medicine has been to invent
biomaterials that accelerate the wound healing process. In this context,
keratin-derived
biomaterial is a promising candidate due to its biocompatibility and biodegradability. In this study, we evaluated an insoluble fraction of
keratin containing casomorphin as a
wound dressing in a full-thickness surgical skin
wound model in mice (n = 20) with iatrogenically induced diabetes. Casomorphin, an
opioid peptide with
analgesic properties, was incorporated into
keratin and shown to be slowly released from the dressing. An in vitro study showed that
keratin-casomorphin dressing is biocompatible, non-toxic, and supports cell growth. In vivo experiments demonstrated that
keratin-casomorphin dressing significantly (p < 0.05) accelerates the whole process of skin wound healing to the its final stage.
Wounds covered with
keratin-casomorphin dressing underwent reepithelization faster, ending up with a thicker epidermis than control
wounds, as confirmed by histopathological and immunohistochemical examinations. This investigated dressing stimulated macrophages infiltration, which favors tissue remodeling and regeneration, unlike in the control
wounds in which neutrophils predominated. Additionally, in dressed
wounds, the number of microhemorrhages was significantly decreased (p < 0.05) as compared with control
wounds. The dressing was naturally incorporated into regenerating tissue during the wound healing process. Applied
keratin dressing favored reconstruction of more regular skin structure and assured better cosmetic outcome in terms of
scar formation and appearance. Our results have shown that insoluble
keratin wound dressing containing casomorphin supports skin wound healing in diabetic mice.