3D Cell Printing of Pancreatic Tissue Constructs using Insulin-Producing Cell Spheroids and its Application for the Treatment of Type 1 Diabetes

Abstract

Type 1 diabetes mellitus (T1DM) is a chronic and debilitating condition that stems from the autoimmune-mediated destruction of insulin-producing beta cells within the pancreatic islets of Langerhans. This pathological process leads to an absolute deficiency of insulin, necessitating lifelong dependence on exogenous insulin therapy to manage blood glucose levels. Despite the widespread application of various therapeutic options, including intensive insulin therapy and continuous glucose monitoring systems, a significant subset of patients with T1DM continues to experience challenges such as unstable glycemic control and hypoglycemia unawareness, which are not adequately addressed by current treatments. Therefore, there is a compelling need for innovative therapeutic strategies that can more effectively mimic the physiological function of pancreatic islets and ensure the long-term viability and functionality of transplanted insulin-producing cells (IPCs). In this comprehensive study, we explore the potential of tissue engineering-based approaches to revolutionize the field of islet transplantation. We propose the use of pancreatic tissue-derived extracellular matrix (pdECM) as a tissue specific bioink that closely mimics the native microenvironment of pancreatic tissues, thereby enhancing the engraftment and function of IPCs derived from human pluripotent stem cells (hiPSCs). Our research demonstrates that the pdECM bioink significantly up-regulates insulin secretion and promotes the maturation of hiPSC-derived IPCs. Furthermore, we investigated the integration of human umbilical vein endothelial cells (HUVECs) within the three-dimensional (3D) culture system. Co-culturing IPCs with HUVECs was found to be beneficial in reducing central apoptosis of islets, a common challenge in 3D tissue constructs, by promoting pre-vascularization. This pre-vascularization is critical for enhancing nutrient and oxygen diffusion throughout the construct, thus improving cell viability and function post-transplantation. Leveraging advanced 3D cell printing technology, we developed volumetric 3D pancreatic tissue constructs (3D PTCs) that are pore-enriched and pre-vascularized, designed to support the engraftment and long-term survival of IPCs. The constructs were meticulously engineered to optimize porosity, which facilitates efficient nutrient and oxygen transport, and to support the integration of IPCs and HUVECs in a spatially organized manner. This structured co-culture system not only enhances the functional performance of the transplanted cells but also accelerates revascularization upon transplantation, improving the overall integration with host tissues. In vivo studies in diabetic rodent models revealed that the 3D PTCs fabricated using pdECM and hiPSC-derived IPCs exhibited high cell viability and sustained insulin production over extended periods. These constructs effectively regulated blood glucose levels, demonstrating their therapeutic potential in T1DM treatment. The use of hiPSCs as a source of IPCs offers a promising avenue for generating an unlimited supply of autologous cells, thus mitigating the risks associated with immune rejection and the scarcity of donor islets. In summary, the findings of this study underscore the transformative potential of 3D bioprinting technology combined with tissue-specific bioinks such as pdECM bioink in creating functional tissue constructs for the treatment of T1DM. The development of pre-vascularized and pore-enriched 3D PTCs represents a significant advancement in islet transplantation, offering a robust platform for enhancing the engraftment, survival, and functionality of transplanted IPCs. Moreover, the strategies and methodologies developed in this research hold broader implications for the field of regenerative medicine, providing efficient cell delivery techniques that could be adapted for various other tissue engineering applications. This study not only contributes to the existing body of knowledge but also paves the way for future research aimed at refining and expanding the clinical applications of bioengineered tissue constructs in the treatment of diabetes and beyond.