Emigdio Mendoza

Enhancing low cost stainless steel implants: bioactive silica-based sol-gel coatings with wollastonite particles

A hybrid organic-inorganic sol-gel coating with the addition of wollastonite particles is used as a potential solution to improve performance of low cost AISI 316L stainless steel. This work is focused on characterising the coatings by studying their synthesis and deposition, electrochemical, and in vitro and in vivo response. The coated implants presented in vitro Ca/P-rich apatitic precursors phases on their surface and acceptable electrochemical behaviour. The in vivo response regarding bone formation seems to be excellent either with the implant in contact with bone marrow, in contact with the endostium or in contact with the trabecular bone. The bioactive and regenerative responses of bone tissue to the TEOS-MTES-wollastonite system over-compensate the coating deterioration reaction, making these coatings as a good way to improve osseo-integration of stainless steel for long term use implants.

APLICACIÓN DE LA MICROSCOPÍA HOLOGRÁFICA DIGITAL EN TRANSMISIÓN PARA LA CARACTERIZACIÓN DEL ESPESOR DE RECUBRIMIENTOS DELGADOS

I n this work an experimental optical system of digital holographic microscopy is implemented to measure thicknesses of thin films. The three-dimensional surface reconstruction was achieved as a phase contrast image obtained through computational processing of digital holograms. These images allow quantitative measurements of thin films thicknesses. This technique was applied to measure silica depositions bioactivated with particles of wollastonite produced by means of sol-gel technique. The depositions were made through dip-coating method with different velocities and using 10% p/p of wollastonite particles dispersed into the silica sol.

Recubrimientos sol-gel con partículas de wollastonita sobre acero inoxidable 316l

El acero inoxidable AISI 316L es el biomaterial mas utilizado para la fabricacion de implantes temporales, pero estos presentan limitaciones para implantes permanentes, debido a la liberacion de iones metalicos. Una estrategia para minimizar la liberacion de iones, es la modificacion superficial de los implantes metalicos por medio de recubrimientos inorganicos ceramicos o vitreos aplicados por el metodo sol-gel. En el presente trabajo, se depositaron recubrimientos con particulas de wollastonita producidos por la tecnica sol-gel sobre acero inoxidable. Se evaluaron la estabilidad de las suspensiones y la biocompatibilidad de los recubrimientos mediante ensayos in Vitro en fluido fisiologico simulado (SBF).