Multi-scale of Immunoprotection Approach using 3D printing technology for Islet Transplantation

Abstract

The transplantation of islet cell is a promising treatment for Type 1 Diabetes Mellitus. However, this has several challenges such as loss of function linked with dispersion and immune response [1]. The islet encapsulation is believed as an encouraging method to safeguard islets from the in vivo environment. The macro-encapsulation which contains a large number of cells in one system is recoverable but it has the limitation of oxygen and nutrients diffusion. In contrast, the micro-encapsulation system that includes a few cells in each capsule has good diffusion rate; however, it is not easy to retrieve the implants [2]. In this study, we suggest the integration of both systems to create a retrievable structure as well as improve the diffusion rate. The macro-encapsulation part is printed using polycaprolactone to provide mechanical support at the transplanted site. Simultaneously, the pancreas tissue-derived decellularized extracellular matrix bioink, which provides tissue-specific microenvironment and camouflage cells from the immune response, is used to encapsulate cells [3]. Moreover, the cells are printed as a form of a spheroid to improve diffusion rate and mimic the natural shape of islets. This system would further be applied to deliver other endocrine cells including Leydig cells or adrenal cells.