Experimental Study Of Xenogenic Acellular Dermal Matrix Incorporated With Silver

Objective The preparation of xenogenic acellular dermalmatrix(xeno-ADM) incorporated with silver. To observe thegraft effect of the xeno-ADM incorporated with silver andexplore a good idea in the treatment of full-thickness skininjuries or serious wound . Method Using 0.25% Trypsin and0.5% TritonX-100 to prepare xeno-ADM, After that the xeno-ADMwas treated with 0.2% silver nitrate to prepare xeno-ADMincorporated with silver. Using the Atomic AbsorptionSpectrometer measures Ag+ content of the xeno-ADM. The xeno-ADMIncorporated with silver was examined by microbial examinationand examined macroscopically and examined microscopically byoptical Electronic microscope and Scanning electronmicroscopic technique. 27 adult rabbits were randomly dividedinto three groups according to different skin grafts, i.e.split-thinkness skin autograft only(group A, n=9 ), xeno-ADMcomposited with split-thinkness skin autograft(group B, n=9),xeno-ADM incorporated with silver composited withsplit-thinkness skin autograft(group C, n=9). One day beforethe operation, 10% Na2S carry depilation on rabbit's back. Afterthe surgical operation anaesthesia succeed, the normalregulations disinfect, in two side lineations of the rabbitspinal column each design two 2cm ×2cm size to create thewound, total 4 create the wounds. Use to roll the stalk typeto take the skin knife to follow to design the line to take thethick skin( thick about 0.2～0.25 mm) of blade to treat to use,then use the surgical operation knife to slice the whole skin ,resulting in the whole layer skin defection. After stoppingthe blood perfectly, handles respectively according dividedgroups .The survival area was measured and calculated two weeksafter the operation. The survival rate was defined as thepercentage of the survival area in the total area oftransplanted epiderm is or derm is .The survival rate of bothepiderm and derm are reaching 90% was regarded as fullsurvival , they are reaching between 40%～90% was regard aspartially survival, They are belowing 40% was regarded asfailure. The data were assessed by Ridit analysis. Two weeksafter the operation, four groups were examined by lymphocyteproliferation activity. The survival rate, the contractiondegree of the grafts and the histogical changes in grafting wereobserved at 2,4,6 weeks after the operation. Results ①Observed under light microscopy, the epidermis was completelyremoved ,there were not any cellular components, hair, follies,sebaceous glands and vessels in the dermis to be found. ②theAg+ content of xeno-ADM incorporated with silver is high ,thebacteriostasis test is obviously higher than othergroups(P<0.05). ③Two weeks after the operation ,the survivalrate of group C grafts is obviously higher than group A or groupB(P<0.05). ④From the result of the lymphocyte proliferationactivity, group B,C is not higher than group A(P>0.05). ⑤After the operation, the contraction degree of A group graftswere severity ,there were full differentiation of epitheliumorderly collagen proliferation and slight reconstruction ofthe epithelial-dermal conjunction structure and the remodelingof the basement membrane in groups B,C. Conclusions Thexenogenic acellular dermal incorporated with silver is an idealdermal substitute, which removed completely the epidermis andcellular components in dermis and retained the integritystructure of collagen fibers, and which have partial,good andstrong bacteriostatic effect.