Protection and functionalization of surgical grade stainless steel with sol gel coatings containing strontium-substituted bioactive glass particles

SHEILA OMAR; LUIS HARO DURAND; MARIELA DESIMONE; ALEJANDRO GORUSTOVICH; JOSE MANUEL PORTO LOPEZ; SILVIA M. CERÉ; JOSEFINA BALLARRE

Natal

Congreso; VII Latin American Congress of Artificial Organs and Biomaterials; 2012

Sociedad Latinoamericana de Biomateriales y Órganos Artificiales

An increasing number of research in bone tissue engineering demonstrate that bioactive silicate glasses (BG) may improve vascularisation and bone regeneration. When BG are modified by substituting strontium (Sr) for calcium (Ca) they are able to generate a local controlled release of Sr-ions. Sr is known to reduce bone resorption and stimulate bone formation. The protection of stainless-steel used as permanent implant by applying a hybrid coating, is one way to modify the metal?s surface, acting as a barrier for ion migration and acting as potential holders for various  kind of functional particles. This work presents the synthesis of coatings made by the sol-gel method using silicon alkoxides and silica nanoparticles as precursors, and functionalized either with BG or Sr-BG particles onto surgical grade stainless steel. The coatings were analyzed superficially with diffractive, spectroscopic, microscopic and electrochemical methods. Electrochemical essays were held in simulated body fluid (SBF) to evaluate the protectiveness of the coatings in time. The presence of apatite-related compounds was confirmed by Raman after immersion in SBF. The in vivo angiogenic potential was evaluated using the quail chorioallantoic membrane (CAM) bioassay. The coating proved to offer an excellent corrosion  protection of the substrate to the aggressive fluids, even after 30 days of immersion where the dissolution and re-deposition of the BG and Sr-BG particles is taking place.