Stability of Asp(B28) Insulin Exposed to Modified and Unmodified Polypropylene.

Polypropylene (PP) plates have been modified with two different hydrophilic polymeric materials, poly(N,N-dimethylacrylamide) (poly(DMAAm)) and poly(poly(ethylene glycol)methacrylate) (poly(PEGMA)) in order to reduce insulin adsorption when the plates were exposed to insulin aspart (Asp(B28) insulin). The influence of surface modification on the chemical and physical stability of Asp(B28) insulin was evaluated by two chromatographic methods, size exclusion chromatography (SEC) and reverse phase high pressure liquid chromatography (RP-HPLC) and the Thioflavin T assay. A clear difference in the stability of Asp(B28) insulin was observed between the three tested surfaces.