Healing effect of porcine acellular dermal matrix combined with split-thickness autologous skin composites on full-thickness cutaneous wounds in SD rats / 中华医学美学美容杂志

Objective To prepare a new type of micropore porcine acellular dermis matrix with the aid of laser (LPADM),and to validate the healing effect of the LPADM through the phrase Ⅰ composite transplanting on the back of the full- thickness skin defects in SD rats.Methods In vitro,the allogeneic fibroblasts were separately cultured with the LPADM (LPADM group) or the non-pore PADM (non-pore LPADM group),while fibroblasts cultured by pure medium were used as control.After culture of 1 day,3 days and 5 days,the contents of IL-10,IL-6,TGF-β1,LN,VEGF expressed by fibroblasts were determined by double-antibody sandwich ELISA method.In vivo,the phrase Ⅰ transplantations of LPADM graft with split-thickness autologous skin were carried on the backs of the full-thickness cutaneous defects of SD rats.The healing condition was observed and analyzed by histological tests.Results The differences of the absorbance value between the LPADMgroup,PADM group and control group in each day were not statistically significant (F=0.050-1.763,P＞0.05).The transplantation of LPADM graft with split-thickness autologous skin graft resulted in high rate of surviving without signs of rejection 3 weeks later.After 1-month of transplantation,the regenerated skin was well enough to be lifted without any serious scars.Conclusions The phrase Ⅰ transplantation of LPADM graft with split-thickness autologous skin graft can accelerate the healing process of full-thickness skin wounds with high biological safety.

CONSTRUCTION AND GROWTH ABILITY STUDY OF A COMPOSITE SKIN COMPOSED OF KERATINOCYTES AND ACELLULAR DERMAL MATRIX / 解放军医学杂志

To investigate the possibility of constructing composite skin, keratinocytes were cultivated in vitro on the epidermal surface of cell free dermis prepared from pig skin.Keratinocytes grown on the dermal matrix were released at selected time points, followed by determining the proliferative capacity with cell number quantity and cell proliferation test. Cells attaching to the dermal matrix after it were seeded for 1 and 2 weeks were observed with histological section HE staining and electron microscopy scanning. Results showed that the number of keratinocytes was markedly increased with culture time. They maintained their proliferative potential after they were seeded on acellular xeno dermal matrix and reached a confluent monolayer or 3 to 6 layers at the 1st and 2nd week after seeding. The data showed that a living composite skin combined with keratinocytes and acellular dermal matrix could be successfully prepared in vitro.

DEVELOPMENT AND STATUS QUO OF THE PERMANENT SKIN SUBSTITUTES / 解放军医学杂志

Although the research work on the permanent skin substitutes was started in our country later than in developed countries, the development has been promising in recent years. The results of this field of research would completely change the fact that deep burn wounds could only be repaired with autologous skin grafting. It is our expectation that with the advent of these permanent skin substitutes, the survival rate of severe trauma could be raised and the quality of wound repair could be improved. In a series of papers published in this issue, the development and the status quo of permanent skin substitutes will briefly be introduced.

BIOACTIVITY AND TRANSPLANTATION OF EGF GENE TRANSFECTED KERATINOCYTE / 解放军医学杂志

To investigate the expression of epidermal growth factor (EGF) of EGF gene transfected keratinocytes in vivo and in vitro after grafting. EGF levels in the supernatant of the culture media of EGF gene transfected keratinocytes cultured for different lengths of time and different passages were determined with ELISA method. Then, the gene transfected keratinocytes were seeded on the surface of acellular dermal matrix, After culture, the composite skin substitutes were grafted onto the full thickness wounds in nude mice. Specimens were harvested at intervals after grafting and stained for EGF with immunohistochemistry. The results showed that keratinocytes transfected with EGF gene secreted EGF, which was detected in the supernatant of the culture, for 5 passages. Immunohistochemical staining method showed that EGF was expressed in the newly generated epidermis 1～3 weeks after grafting of the composite skin substitute. The data showed that gene transfected keratinocytes could express EGF stably in vivo and in vitro , which would be of benefit to the construction of the tissue engineering skin.

EXPERIMENTAL STUDY OF TRANSPLANTATION AND THE FATE OF COMPOSITE SKIN COMPRISING MIXED KERATINOCYTES SEEDED ON ACELLULAR DERMAL MATRIX / 解放军医学杂志

To investigate the fate of composite skin comprising mixed keratinocytes seeded on acellular dermal matrix (ADM) after its transplantation to the wound. Newborn BALB/c and human keratinocytes were mixed in various ratios, seeded on the surface of ADM, and cocultured. The composite skin substitute were then grafted onto the full thickness skin wounds in BALB/c mice. The fate of human keratinocytes was observed. The results showed that the composite skin substitutes could close the full thickness wounds in BALB/c mice. Human keratinocytes were mainly located in the upper layer of the epidermis, and were gradually replaced by BALB/c keratinocytes. This indicated that the mixed culture of keratinocytes of two different species on ADM could close full thickness wounds, having the advantages such as saving the donor skin and shortening the culture time in vitro .