Silver Nanoparticles Improve the Biocompatibility and Reduce the Immunogenicity of Xenogeneic Scaffolds Derived from Decellularized Pancreas

Xenogeneic scaffolds derived from the decellularized pancreas are plausible biomedical materials for pancreatic tissue engineering applications. During the decellularized process, the ultrastructure of extracellular matrices, including collagen fibers, was destructed, which leads to the decrease of mechanical strength and the immune-inflammatory response after transplantation in vivo. The cross-linking method plays an important role in increasing mechanical strength and reducing the inflammatory potential of decellularized scaffolds. However, no ideal cross-linking agent has been identified for decellularized pancreatic scaffolds yet. In this study, a cyclic perfusion system was used to cross-link decellularized pancreatic scaffolds from Sprague Dawley rat with silver nanoparticles (AgNPs). The optimum concentration of AgNPs was selected according to the scanning electron microscope observation and mechanical evaluation, as well as cytotoxicity to human umbilical vein endothelial cells and MIN-6 cell lines in vitro. The inflammation after transplantation in vivo was evaluated by hematoxylin and eosin staining; M1/M2 polarization phenotype of macrophages was further evaluated. Our results showed that after cross-linking, the scaffold possessed better mechanical property and biocompatibility, with the polarization of M2 macrophages increased. Thus, AgNP-cross-linked pancreatic acellular scaffold can provide an ideal scaffold source for pancreatic tissue engineering.