The Effects Of UVB On The Biological Characteristics Of BAMA Miniature Pig's Skin

BackgroundAllogeneic and xenogeneic skin are the regular dressings in the treatment of large burn wounds as the substitute of autologous skin. However, both allogeneic and xenogenic skins face strong immune rejection which may result in early necrosis in skin grafts shortly after transplantation. Radiation with Ultraviolet Radiation B (UVB) ranging between 320-280nm wavelength has been found to be capable of reducing graft immunogenicity to some degree in addition to disinfection, and recognized as a potential and simple method to reduce skin antigenicity and further to prolong its survival in the procedure of sin grafting. However, a detailed study is required to find out the most proper radiation dose by which the skin antigenicity can be effectively reduced without remarkable viability loss. ObjectiveThis study has investigated the effects of different dosees of UVB radiation on the immnogenicity, disinfection and viability of BAMA miniature pig skins, in order to find out a proper dose of UVB radition with which the skin immunogenicity can be reduced with no remarkable viability loss.Methods and results1. Tests of immunogenicity1.1 Lymphocyte proliferation testUVB reduces the immunogenicity of skin in a dose-dependent manner. In 30J/cm2, the reduction rate was 14.3%; In 60J/cm2, it was 42.9%; The largest reduction rate (99.9%) was observed when the dose was 360J/cm2.1.2 Langerhans cell (LC) countsThe LCs in fresh skin were stained to be black in a shape like that of dendritic cells. The LC counts in skin was remarkably reduced or even completely disminished after UVB radiation. The LC counts in skin was reduced by UVB radiation in a dose-dependent manner. There was a positive correlation between the immunogenicity and the number of LC in the skin treated by UVB.2. Germ-carrying detectionUVB has a function of bacteriostasis. The germ-carrying of skin became less with the augmentation of UVB dose. However, there was still some germ even when the largest dose of UVB was used.3. UVB caused damages to skinWe investigated the viability of skin treated by UVB by MTT method. Result showed that skin viability decreased when the UVB dose was augmented from 0 to 90 J/cm~2,. However, the viability was observed to rise then decreased when the UVB dose was in the range of 90—360 J/cm~2.ConclusionsUVB has the function of bacteriostasis; UVB reduced skin immunogenicity in a dose-dependent manner; The number of LC became less when the dose of UVB was augmented, and there was a positive correlation between UVB dose and skin immunogenicity; UVB radiation resulted in damages to the skin to some degrees. The immunogenicity, damages and germ-carrying of the skin were all on the lowest levels when the UVB dose was in the range of 30-60 J/cm~2. The results in this study laid down the experimental foundation for better Allogeneic or xenogenic skin grafting.