Gelatin-Modified Biomimetic Apatite Coatings

Biomimetic coatings constituted of gelatin and nanocrystalline apatite were deposited on titanium substrates from a slightly supersaturated calcium phosphate (CaP) solution enriched with different amounts of gelatin. Although the biopolymer inhibits the crystallization of the inorganic phase, as shown by the reduction of the mean dimensions of the spherical aggregates and of the degree of crystallinity of the apatitic phase on increasing gelatin concentration, the deposition of a uniform layer of nanocrystalline apatite takes place in a few hours. Gelatin incorporation into the precipitate increases on increasing its concentration in solution, up to about 20 wt%. Osteoblast-like MG63 cells cultured on the coatings display good proliferation and increased values of the differentiation parameters with respect to the control. The presence of gelatin improves significantly the biological response to the biomimetic coatings, as shown by the higher values of proliferation, collagen type I and osteocalcin production, as well as alkaline phosphatase activity stimulation.