Chitosan-oxychitin coatings for prosthetic materials

Plates of Ti-6Al-4V alloy were plasma-sprayed with hydroxyapatite and with bioactive glass. Chitosan acetate solution was then used to deposit a chitosan film upon the plasma-sprayed layers, which was further reacted with 6-oxychitin to form a polyelectrolyte complex. The latter was optionally contacted with 1-ethyl-3-(3dimethylaminopropyl)carbodiimide at 4°C for 2 h to form amide bonds between the two polysaccharides. Uniform flat surfaces exempt from fractures were observed with an electron microscope. The chitosan film was also submitted to acetylation with acetic anhydride in methanol to obtain a chitin film. In all cases the modified chitosan films were insoluble. The results are useful for the preparation of prosthetic articles possessing an external organic coating capable to promote colonization by cells, osteogenesis and osteointegration.