Figure 3.
Autocoating forms conformal PEM thin films on islets while maintaining viability, morphology, and function. a) PEM films appear uniform and without major defects after 8 bilayers of automated coating. b) Both uncoated and autocoated islets had mean viability of 99.3% (p=0.7). Centrifugation for 15 minutes, a treatment known to induce minor damage to islets, resulted in a small but statistically significant drop in viability (to 97.9%, p=2.25 × 10−7). c–e) To probe for changes in islet surface morphology, light micrographs (representative images, (c)) were processed with the ImageJ particle detection algorithm (d), and (e) circularity was computed for each islet. (f) Mean circularity of autocoated islets (0.570) did not differ significantly compared to uncoated islets (0.578, p=0.7) or islets coated with the traditional manual coating method (0.532, p=0.7), but circularity was significantly reduced in centrifuged islets (0.301, p=1.2 × 10−16 vs autocoated). (g) Insulin secretion was not significantly different between uncoated and autocoated islets at either basal (3.3mM, p=0.6) or high (16.7mM, p=0.7) glucose concentrations. a–f) n=30–60 islets; g) n=60–100 islets per condition; * indicates p<0.001