In the early stage of transplantation, macrophage cells play an important role in reacting with the transplantation materials. Minimizing the reaction by maintaining the low inflammation of the original decellularized porcine pericardium (dPPC) after the modification process is necessary to avoid rejection. Over the healing process, the fibroblast is the key cell to form the adhesion between the membrane and the wound site. Repelling the fibroblast to adhere to the membrane surface is important to achieve good wound healing and ensure that no adhesion forms. Therefore, we investigated the repose of the fibroblast and THP-1 cells to the multi-arm PEGNHS-modified dPPC.
In this study, dPPC was prepared by the high-hydrostatic-pressure method and confirmed by means of H&E staining and residual DNA quantification. It was then modified with α-succinimidyloxyglutaryl-ω-succinimidyloxyglutaryloxy-polyoxyethylene (2-arm PEGNHS), pentaerythritol tetra (succinimidyloxyglutaryl) polyoxyethylene (4-arm PEGNHS), and hexaglycerol octa(succinimidyloxyglutaryl) polyoxyethylene (8-arm PEGNHS) and confirmed by ATR-FTIR, anti-PEG antibodies, and ninhydrin assay. The modification was carried out over the amine bond between the NH2 of dPPC and the NHS functional group of PEG with molar ratios of 1:1 and 1:2. The prediction of the inflammation levels and fibroblast repelling in vitro was performed by using THP-1 cells and NIH3T3 cells, respectively.
The dPPC was confirmed by the loss of cellular nuclei and the residual DNA. The modification was confirmed by increasing the C-O-C bond and by the the brown color of the anti-PEG antibodies. The free amine group was significantly reduced after the introduction of the PEG molecules. Among all conditions, 8-arm PEG-modified dPPC in a molar ratio 1:2 was significantly repelling the fibroblasts, and then, cells started to restore on day 7 of culture. The THP-1cells were also repelling and exhitibed a low inflammation secretion level. With these observations, the technology of cell-repelling surfaces was developed and could be used to fabricate anti-adhesion membranes.
