Immune response to subcutaneous implants of alginate microcapsules

Abstract In vivo implantation of biomaterialselicits myriad of immune interactions known as host inflammatory response. This immune response often undermines the efficiency and performance of implanted biomaterials, especially in the case of cell-encapsulated biomaterials. Here, we sought to study the host immune response towards alginate microcapsules following by subcutaneous implantation. Among various immune factors, we specifically focused on three key players i.e. macrophages, neutrophils, and collagen fibers. We implanted ultrapure low viscosity high gluronate (UPLVG) alginate capsules subcutaneously in the immunocompetent mice. Laser scanning confocal microscopy(LSCM) was conducted to analyze the macrophage and neutrophils infiltration around and into the capsules. Trichrome stainingwas also performed to investigate the collagen fibrosis. Our findings suggest that while UPLVG capsules could block the infiltration of macrophages and neutrophils into the alginate microcapsules, they form a thick fibrotic layer forms around them.