Impact of Polymer-Bound Iodine on Fibronectin Adsorption and Osteoblast Cell Morphology in Radiopaque Medical Polymers: Tyrosine-Derived Polycarbonate Blends as a Model System
Imaging of polymer implants during surgical implantations is challenging in that most materials lack sufficient X-ray contrast. Synthetic derivatization with iodine serves to increase the scattering contrast but results in distinct physicochemical properties in the material which influence subsequent protein adsorption and cell morphology behavior. Herein we report the impact of increasing iodine inclusion on the cell morphology (cell area and shape) of MC3T3-E1 osteoblasts on a series of homopolymers and discrete blend thin films of poly(desaminotyrosyl tyrosine ethyl ester carbonate), poly(DTE carbonate), and an iodinated analogue poly(I(2)-DTE carbonate). Cell morphology is correlated to film chemical composition via measuring fibronectin (FN) adhesion protein adsorption profile on these films. FN exhibits up to 2-fold greater adsorption affinity for poly(I(2)-DTE carbonate) than (poly(DTE carbonate)). A correlation was established between cell area, roundness, and the measured FN adsorption profile on the blend films up to 75% by mass poly(I(2)-DTE carbonate). Data suggest that incorporation of iodine within the polymer backbone has a distinct impact on the way FN proteins adsorb to the surface and within the studied blend systems; the effect is composition dependent.