In vitro morphogenesis of PANC-1 cells into islet-like aggregates using RGD-covered dextran derivative surfaces.

Substrates bearing low-fouling carboxymethyl dextran (CMD) upon which RGD is covalently grafted were validated to study PANC-1 cell differentiation in serum-free medium. When exposed to RGD-CMD, cells lightly adhered to the surface and formed islet-like aggregates (ILAs) in contact with the surface. PANC-1 were non-adherent on RGE-CMD, CMD, and tissue culture polystyrene surfaces and aggregated in suspension forming ILAs. RGD-CMD resulted in smaller ILAs. Ki67 and CK-19 expression decreased after 3, 7, and 14 days. E-cadherin expression did not change from 3 to 7 days, but decreased after 14 days. For each marker, there was no difference in the expression between the surfaces. After 14 days, ILAs weakly expressed insulin and glucagon and the expression level was independent of the surfaces. No convincing level of insulin or glucagon was detected by immunostaining at 3 and 7 days. A higher level of insulin release was detected in the media after 14 days for cells grown on RGD-CMD. After 14 days, there were three-fold more cells on RGD-CMD surfaces compared to cell numbers found in other culture conditions. α(5) integrin expression was rampant throughout ILAs for all four surfaces. α(V)β(3) integrin expression was only noticeable for ILAs cultured on RGD-CMD surfaces.