Polysialic Acid Hydrogel for Reducing Foreign Body Reactions in Implanted Polyurethane Materials

Long-term retention of polyurethane (PU) materials as vascular channels, due to foreign body reactions causing fiber encapsulation, will eventually lead to material failure. In this research, an interfacial interpenetrating grafting approach is adopted to graft PSA onto the surface of the PU material (PU-sg-PSA), which exhibits excellent resistance to fibrous encapsulation. The experimental results indicated that, compared with the unmodified PU material, the PU-sg-PSA material exhibited a reduced level of non-specific protein adhesion. In terms of macrophage behavior, macrophages on the PU-sg-PSA material has low expression levels of NO. In a rat subcutaneous implantation model, the number of macrophages surrounding the PU-sg-PSA material was fewer, and the formed fibrous encapsulation layer was thinner compared that to unmodified PU.