PEG-based organic–inorganic hybrid coatings prepared by the sol–gel dip-coating process for biomedical applications

In the present work, the application of functional coatings on metallic implants was proposed to delay implant failure by improving tissue tolerance and implant osseointegration. Three bioactive and biocompatible organic–inorganic hybrid nanocomposites, consisting of polyethylene glycol (PEG) embedded in a SiO2, ZrO2, and TiO2 matrix, respectively, were synthesized via the sol–gel method. Materials in the sol phase were used to dip-coat titanium grade 4 substrates for use as dental and orthopedic implant models. To investigate the influence of the glass matrix and the polymer amount on the coating structure, and thus on their biological properties, several hybrids were obtained by adding different weight percentages of PEG to each glass matrix. Attenuated total reflectance Fourier transform infrared spectroscopy confirmed the presence of the polymer in the nanocomposites and scanning electron microscopy showed that an increase in the PEG content allows crack-free coatings to be obtained. Moreover, the bioactivity and biocompatibility of both the uncoated and coated titanium implants were investigated and compared by an in vitro test. The results revealed that coated substrates have more enhanced biological performance than the uncoated ones. The bioactivity is not significantly affected by either the inorganic matrix or the PEG amount, whereas the presence of polymer makes the films more biocompatible. POLYM. ENG. SCI., 57:478–484, 2017. © 2017 Society of Plastics Engineers.