SliceChip: a benchtop fluidic platform for organotypic culture and serial assessment of human and rodent pancreatic slices.

Enzymatically isolated pancreatic islets are the most commonly used ex vivo testbeds for diabetes research. Recently, precision-cut living slices of human pancreas are emerging as an exciting alternative because they maintain the complex architecture of the endocrine and exocrine tissues, and do not suffer from the mechanical and chemical stress of enzymatic isolation. We report a fluidic pancreatic SliceChip platform with dynamic environmental controls that generates a warm, oxygenated, and bubble-free fluidic pathway across singular immobilized slices with continuous deliver of fresh media and the ability to perform repeat serial perfusion assessments. A degasser ensures the system remains bubble-free while systemic pressurization with compressed oxygen ensures slice medium remains adequately oxygenated. Computational modeling of perfusion and oxygen dynamics within SliceChip guide the system's physiomimetic culture conditions. Maintenance of the physiological glucose dependent insulin secretion profile across repeat perfusion assessments of individual pancreatic slices kept under physiological oxygen levels demonstrated the culture capacity of our platform. Fluorescent images acquired every 4 hours of transgenic murine pancreatic slices were reliably stable and recoverable over a 5 day period due to the inclusion of a 3D-printed bioinert metallic anchor that maintained slice position within the SliceChip. Our slice on a chip platform has the potential to expand the useability of human pancreatic slices for diabetes pathogenesis and the development of new therapeutic approaches, while also enabling organotypic culture and assessment of other tissue slices such as brain and patient tumors.

Pentagalloyl Glucose (PGG) Prevents and Restores Mechanical Changes Caused by Elastic Fiber Fragmentation in the Mouse Ascending Aorta.

Thoracic aortic aneurysm (TAA) is characterized by dilation of the aorta that can lead to dissection or rupture. Degradation of elastic fibers is a consistent histopathological feature of TAA that likely contributes to disease progression. Pentagalloyl glucose (PGG) shows promise for stabilizing elastic fibers in abdominal aortic aneurysms, but its efficacy and mechanical effects in the thoracic aorta are unknown. We simulated TAAs using elastase (ELA) to degrade elastic fibers in the mouse ascending aorta and determined the preventative and restorative potential of PGG. Biaxial mechanical tests, constitutive model fitting, and multiphoton imaging were performed on untreated (UNT), PGG, ELA, PGG + ELA, and ELA + PGG treated aortas. PGG treatment alone does not significantly alter mechanical properties or wall structure compared to UNT. ELA treatment alone causes an increase in the unloaded diameter and length, decreased compliance, significant changes in the material constants, and separation of the outer layers of the aortic wall compared to UNT. PGG treatment before or after ELA ameliorates the mechanical and structural changes associated with elastic fiber degradation, with preventative PGG treatment being most effective. These results suggest that PGG is a potential pharmaceutical option to stabilize elastic fibers in TAA.