The observation of the process of dermal regeneration in wound healing

Objective To study the regenerative pattern of dermis in full layer wound healing process,and the relation to regeneration of epidermis and basal membrane. Methods Full layer wounds were created at the dorsal site of rats(n=10),the specimens were obtained at 1st,2nd,3rd,4th,5th week;HE and PAS staining were performed,and the alkaline water maceration method was used for preparing scanning electronic microscope(SEM) specimens;the healing process of dermis was observed under light microscope and electronic scanning microscope. Results The wound edge showed the regeneration of immature epidermis towards central granulation tissue at the early stage,followed by the growth of dermis adjacent to epidermis.The PAS positive layer was seen between neo-dermis and epidermis at the peripheral wound 5 weeks after wounding,while the central wound exhibited incontinuous PAS positive layer.Under the SEM study,the papillary dermis developed toward central wound prior to reticular dermis,which grew relatively slower and syncretized with the granulation tissue at the later phase. Conclusions The papillary and reticular dermis exhibit distinct regenerative pattern in wound healing.The regeneration of papillary dermis is closely related to epidermis.The neo-formation and migration is prior to dermal growth,and the basal membrane begins to form after the formation of epidermis and dermis.