Coating of surfaces with stabilized reactive micelles from poly(ethylene glycol)-poly(DL-lactic acid) block copolymer

Reactive micelle was prepared from an end-derivatized block copolymer, acet al-poly(ethylene glycol)poly(DL-lactic acid)-methacrylate (PEG-PLA). The bl ock copolymer of PEG-PLA formed a micelle with a diameter of approximately 30 nm determined from dynamic Light scattering. The glass and Si wafer surf aces coated with 3-aminopropyltriethoxysilane and poly(dimethylsiloxane) (P DMS) treated with N-2 + H-2 plasma were coated with the micelle, and the co ating was characterized by zeta-potential profile, dynamic contact angle, a nd atomic force microscopy. The micelle with polymerized core maintained it s structure on the surface while the nonpolymerized micelle was disrupted u pon attachment. Compared with PEG coatings, micelle coating has higher adva ncing angle, and larger hysteresis, resulting from the conformational diffe rence of PEG between the homopolymer and the micelle, and the micelle-induc ed surface topography. The zeta-potential of glass surface coated with the micelle is similar to that with PEG despite the larger dimension of the mic elle. However, plasma-treated PDMS showed appreciable magnitude of zeta-pot ential even PEG was coated, while micelle-coated PDMS showed similar zeta-p otential to the glass coated with the micelle. The coatings with PEG-PLA mi celles can be applied to the design of nonfouling surfaces and medical impl ants.