Biomimetic growth of hydroxylapatite on SiO2-PMMA hybrid coatings

A PMMA-SiO2-hybrid material was produced through a modified sol-gel route by using as precursors tetraethyl orthosilicate (TEOS), Methyl methacrylate (MMA) and 3-(Trimethoxysilyl)propyl methacrylate (TMSPM) as the coupling agent. The hybrid films were deposited by dip coating onto 316 L stainless steel plates and then these substrates were immersed in a Simulated Body Fluid (SBF) at 5, 10, 15, 20 y 25 days at a constant temperature of 37 °C and pH=7.4. The resulting hydroxylapatite (HAp) overgrown coatings were characterized by X-ray diffraction, scanning electron microscopy and infrared spectroscopy. After 5 days of immersion in SBF the substrate is partially covered with HAp spherulites and after 15 days the surface is entirely and uniformly coated.