Abstract
The aim of this study was to determine the biocompatibility of an acellular human amniotic membrane biomaterial, which may have clinical utility for cell delivery. Human amniotic membrane was decellularized using 0.03% (w/v) sodium dodecyl sulfate (SDS), with hypotonic tris buffer and protease inhibitors and nuclease treatment. The membrane was terminally sterilized using an optimal concentration of peracetic acid. Residual SDS present within the acellular membrane was quantified using radio-labeled C14 SDS. In vivo biocompatibility was assessed by implantation of acellular human amniotic membrane subcutaneously into mice for 3 months and comparison with fresh and glutaraldehyde-fixed tissue. Cellular infiltrate into the explanted tissues was characterized using monoclonal antibodies against the following cell surface markers: CD3, CD4, CD34, and F4/80. Calcification was determined using the Von Kossa's stain. The potential of acellular human amniotic membrane to support the attachment and proliferation, and maintain viability of primary human dermal fibroblasts and primary human dermal keratinocytes was assessed in vitro, using a static culture system. Peracetic acid at a concentration of 0.1% (v/v) was sufficient for the sterilization of acellular amniotic membrane. Levels of SDS present within the acellular tissue were 0.62 ± 0.13 μg/mg. Analysis of explanted samples from the mice indicated that acellular amniotic membrane contained low numbers of T-cells and high numbers of fibroblastic cells, macrophages, and endothelial cells, indicative of a wound-healing response. There was no evidence of calcification present within explanted acellular amniotic membrane compared to explanted glutaraldehyde-fixed amniotic membrane. Acellular amniotic membrane was shown to be capable of supporting the attachment and proliferation of primary human fibroblasts and keratinocytes. The viability of the cells was maintained for up to 4 weeks. Cell-seeded acellular amniotic membrane has the potential for delivering autologous or allogeneic cells to treat a variety of conditions, including diabetic foot ulcers, corneal defects, and severe skin burns.