Inflammatory response to peritoneal implantation of alginate–poly-l-lysine microcapsules

Cellular Plasticity of Inflammatory Myeloid Cells in the Peritoneal Foreign Body Response

“…This finding is in agreement with results of other studies demonstrating the involvement of lymphocytes in the tissue response to foreign materials. [33][34][35] We demonstrate that implantation of sterile foreign objects in the peritoneal cavity initiates an inflammatory response in which EGFP ϩ Gr1 ϩ (Ly6C ϩ ) monocytes and granulocytes are rapidly recruited to the peritoneal cavity and encapsulate the foreign object. Morphological analysis shows that the EGFP ϩ Gr1 ϩ (Ly6C ϩ ) cells, which enter the peritoneal cavity and encapsulate the implanted object in the early phase (at day 2), are primarily granulocytes, with monocytes representing only a minor subset.…”

Biocompatibility of alginate–poly-l-lysine microcapsules for cell therapy

“…This was observed following the injection of saline without microcapsules (sham implantations) and by performing a study at short periods post implantation [57]. The non-specific activation of the abundant peritoneal immune cell population (85% macrophages) by the implantation procedure, the massive recruitment of additional inflammatory cells and release of pro-inflammatory cytokines result in the transplantation of microcapsules into a very hostile environment.…”

Progress technology in microencapsulation methods for cell therapy

“…Long-term in vivo applications have, however, been hampered by early graft rejection owing to fibroblast overgrowth as well as by mechanical and chemical instability of the capsules. As PLL evokes inflammation and tissue fibrosis, 112,113 another widely-adopted option is to add an outer coating of alginate to shield the PLL from host tissue, thereby improving biocompatibility 91 and decreasing permeability. 92 However, because the outer alginate layer is exposed, questions have been raised about its stability.…”