Cytocompatible biointerface on poly(lactic acid) by enrichment with phosphorylcholine groups for cell engineering

A tunable biointerface was designed and prepared using a novel biocompatible phospholipid polymer composed of 2-methacryloyloxyethyl phosphorylcholine (MPC), n-butyl methacrylate, and isomeric poly(lactic acid) macromonomer. The phospholipid polymer was coated on a substrate, and the surface characterization was examined in terms of surface elemental analysis by X-ray photoelectron spectroscopy and dynamic contact angle measurements. The phosphorylcholine (PC) group in the MPC units was enriched after immersion in a buffer solution following heating above its glass transition temperature. After the enrichment of the phosphorylcholine group, the surface wettability was significantly improved and the adsorption behavior of serum proteins was investigated. Albumin and γ-globulin hardly adsorbed on the polymer surface as a result of the surface enriched PC group. On the other hand, adsorption of fibrinogen, which is a cell adhesive protein, was maintained at almost the same level as that from the dry surface. As a result the biointerface on the substrate had dual functions, cytocompatibility by a reduction of the general protein adsorption and cell adhesivity based on the adsorption of fibrinogen. The material duality provides for a tunable biointerface and thus an interesting candidate for cell engineering is formed.