Scalable 3D bioprinting of human islets in a pancreatic decellularized extracellular matrix-enriched bioink for...

Allogeneic cell transplantation such as beta-cell replacement for treatment of type 1 diabetes (T1D) is constrained by poor graft survival and functionality, immune rejection, and the lack of scalable biomanufacturing processes. Here, we engineered functional human islet constructs that replicate the physiomimetic human pancreatic microenvironment by employing a clinically-scalable 3D bioprinting system. To support human islet viability and function, we developed alginate-based bioinks incorporating human pancreatic decellularized extracellular matrix (dECM). These bioink formulations were optimized for shear-thinning properties for extrusion of human islets (HI), as well as selective permeability that supports nutrient and therapeutic molecule exchange. Extrusion-based printing parameters were refined to minimize shear stress-induced damage to human islets. The resulting bioprinted pancreatic constructs demonstrated robust structural integrity, high human islet viability (>85%), and long-term glucose-stimulated insulin secretion (GSIS) over a 21-days in vitro culture period, even at a high islet packing density (10,000 islet equivalent/mL) while free islet controls displayed a significant functional decline. The higher performance of bioprinted islets maybe attributable to the supportive 3D dECM-rich microenvironment mitigating culture-induced stress by recapitulating the islet pancreatic niche. This scalable 3D dECM-alginate bioprinted platform represents a new advanced functional material for advancing clinically translatable bio-artificial pancreas therapies for T1D. STATEMENT OF SIGNIFICANCE: Type 1 diabetes affects millions of people worldwide, yet cell-based therapies remain limited by poor graft survival and the lack of scalable manufacturing methods. This study introduces a clinically scalable 3D bioprinting strategy that embeds human pancreatic islets within a biomimetic, decellularized pancreas enriched bioink. Unlike previous approaches, this platform preserves islet viability and glucose-responsive insulin secretion over long-term culture, even at high, clinically relevant islet densities. By combining optimized bioprinting parameters with a pancreas-specific extracellular matrix, this work overcomes key trade-offs between printability, mass transport, and islet function. These findings represent an important step toward manufacturable, bioengineered pancreatic constructs for next-generation diabetes cell replacement therapies.