Engineering the optimal site for islet cell transplantation: proof-of-concept for a decellularized rat pancreas

Introduction: A cell based treatment for type 1 diabetes can significantly reduce the occurence of life-threatening complications, like hypoglycemic episodes, and progression of diesease-associated co-morbidities. Islet cell transplantation is able to achieve insulin independence in 40 – 60% of cases. But unfortunately graft-site-specific issues still remain a major obstacle. The aim of this study was to address them by engineering a decellularized pancreas graft, which could be used for the engineering of an endocrine Neo-Pancreas.

Methods: Pancreata from 32 Fisher DPP-IV^- rats (m/f, 150 – 550 g) were retrieved. 24 were cannulated either through the I) abdominal aorta, II) the portal vein or the III) bile duct. All organs were then perfused with an identical protocol using Triton-X₁₀₀ and SDS. The rest was used as controls.

Decellularized matrices were evaluated by histology (H/E, Sirius-Red, Alcian-Blue), immunohistochemistry (Collagen-IV, Laminin, Fibronectin) and assays to measure the remaining DNA and sGAG content. Data was regarded significant when p < 0.05.

Results: Macro- and microscopic conservation of the extracellular matrix could be observed. No residual cellular components were found.

Total DNA content significantly declined in experimental groups (p = 0.004). sGAG content appeared significantly higher in experimental groups (p = 0.027). No statistical difference was observed between the three experimental groups (DNA: p = 0.812; sGAG: p = 0.8980).

Discussion: We present three protocols for the perfusion decellularization of rat pancreata. Our protocol is quick, reproducible and can be used for different settings.

Further studies now have to evaluate if the graft can be repopulated with cells and can serve as an environment to solve graft-site-specific issues.