Multilayered implantation using acellular dermal matrix into nude mice.

Soft tissue augmentation using acellular dermal matrix has gained popularity to overcome the shortcomings of autogenous and alloplastic materials. Sometimes it needs multilayered stacking to obtain enough volume. In this study, we investigated the efficacy of multilayered implantation using acellular dermal matrix (MatriDerm(®)) for soft tissue augmentation. MatriDerm was implanted subdermally on each side of the dorsum of nude mice (n = 20), stacked two layers thick in the control group and three layers thick in the experimental group. Alterations of thickness, degree of angiogenesis, and collagen and elastin fiber syntheses were observed over 40 days. Three-layered implantation with MatriDerm maintained its volume similarly as in two-layered implantation, although the thickness decreased after 30 days in both groups. At the early stage of implantation, angiogenesis and collagen and elastin fiber syntheses occurred fluently on the central portion, which is the farthest away from the surface in contact with the host tissue. Collagen and elastin fibers became more concentrated over time, and the original structure of MatriDerm could not be maintained due to being replaced with newly formed collagen and elastin fibers 40 days after implantation. Multilayered implantation with MatriDerm is considered appropriate for tissue ingrowth and can be used as a substitute for soft tissue augmentation.