Personalized Alginate Encapsulation: The Role of Autologous Blood Additives in Parathyroid Cell Transplantation

Abstract

The only therapeutic intervention for hypoparathyroidism is parathyroid transplantation, but graft rejection is a concern. This study sought to mitigate this problem by utilizing the patient's blood, serum, or plasma in the transplant. To accomplish this objective, blood additives derived from Sprague-Dawley rats are incorporated within alginate, and human parathyroid cells are encapsulated. The prepared microbeads are monitored for mechanical properties, followed by xenotransplantation into rats for the evaluation of cell function and immunological response. Biodegradation data showed that the structural integrity of the microbeads containing blood and plasma is superior to serum, while the durability of plasma-including microbeads is only comparable to that of the alginate-only group. Plasma-including microbeads released the highest levels of parathyroid hormone (PTH), both in vitro and in vivo. This behavior could be attributed to the beneficial impact of plasma on cellular function while regulating immune response. Blood incorporation provoked an elevated immune response while concurrently offering minimal support to the encapsulated cells. A notable elevation in CCL2 (MCP-1) chemokine levels is observed in both blood and alginate-only microbead groups, correlating with CD68 expression. These findings demonstrated that autologous plasma addition may regulate the immune system, thereby diminishing the risk of rejection in cell transplantations.