TREATMENTS TO INDUCE THE NUCLEATION AND GROWTH OF APATITE-LIKE LAYERSON POLYMERIC SURFACES AND FOAMS

In this work, a bioactive glass is used as a percusor of calcium-phosp hate (Ca-P) film deposition onto several polymer-based materials. Both bioinert (high molecular weight polyethylene, HMWPE), and biodegradab le (corn starch-based blends, SEVA-C) polymers, unreinforced or reinfo rced with hydroxylapatite (HA), were coated by the very simple propose d route. Also polyurethane (PU) foams, with an open-cell structure, we re mineralized by the proposed method. In fact, it was possible to ind uce the growth of the Ca-P films not only at the surface, but also in the bulk of the PU foam. These cellular materials are intended for can cel to us bo ne replacement applications. The morphology of the formed fi I ms was strongly dependent on the used substrate, its polar chara cter, and on the presence of HA in its composition, as observed by SEM . Nevertheless, a well defined needle like structure was observed in a ll samples at high magnifications. The Ca:P ratios of the films were b etween 1.5 and 1.7, i.e. in the range of tricalcium phosphate-hydroxyl apatite. Raman spectroscopy and thin-film x-ray diffraction (XRD) evid enced the formation of mostly amorphous calcium-phosphate films. After scraping the coating from the polymer surface and heat-treating the r esulting powder at 1000 degrees C for 1 h, HA and beta-tricalcium phos phate (TCP) typical peaks were found on XRD patterns.