The effect of different electrodeposition variables of chitosan coatings on Ti-6Al-4V substrates is studied. Electrolytic solutions containing chitosan at 0.1, 0.5, and 1.0 wt/v% was used to coat Ti-6Al-4V grit-blasted samples through electrodeposition, at 1.5 and 3.0 V, for 2.5, 20 and 30 min. Coating surface morphology was analyzed by scanning electron microscopy. Adhesion behavior was characterized by scratch testing, and coating stability under physiological conditions was assessed by swelling test. Electrodeposited coatings with longer times and high chitosan concentrations produced porous coatings, with a hydrogel-like structure, with better surface adhesion than those at lower concentrations and times. Swelling tests displayed a high initial swelling with posterior rapid degradation and stabilization at 3h, indicating the potential need for a crosslinking agent. These results suggest that chitosan electrodeposition has great potential for coating applications of metallic implants, and further in vitro cell assays are proposed for future studies.

Abstract Porous structures TiO2-Na0.8Ti4O8-Na2Ti6O13 were obtained by mixing, compacting and sintering TiO2 with sodium bicarbonate as porogenic agent (15 and 30 wt.% of NaHCO3). The samples were compacted and treated at 1100 °C for 4 h and 8 h. The effects of sintering time and the weight percent of NaHCO3 on surface mechanical properties, porosity and cytotoxicity were analyzed. The X-ray diffraction patterns were refined by the Rietveld method. Microstructures were observed by scanning electron microscopy and the effect of material composition on the cellular response in vitro was evaluated using a LDH-cytotoxicity assay. The porosity varied between 3.2% and 11.9%, the surface microhardness between 251.4 HV0.2 and 851.6 HV0.2. The cytotoxicity results on the CHO cell line (Chinese Hamster ovary) show that the porous structures are not cytotoxic and has potential for orthopedic tissue engineering applications.

Resumen Se obtuvieron estructuras porosas de TiO2-Na0.8Ti4O8-Na2Ti6O13 mezclando, compactando y sinterizando TiO2 con bicarbonato de sodio como agente porogénico (15% y 30% en peso de NaHCO3). Las muestras se compactaron y trataron a 1100 °C durante 4 h y 8 h. Se analizaron los efectos del tiempo de sinterización y el porcentaje en peso de NaHCO3 sobre las propiedades mecánicas superficiales, porosidad y citotoxicidad. Los patrones de difracción de rayos X se refinaron por el método Rietveld, usando GSAS. Las microestructuras se observaron mediante microscopía electrónica de barrido y el efecto de composición de los materiales sobre la respuesta celular in vitro se evaluó usando ensayo LDH de citotoxicidad. La porosidad varió entre 3.2% y 11.9%, la microdureza superficial entre 251.4 HV0.2 y 851.6 HV0.2. Los resultados de citotoxicidad en la línea celular CHO (ovario de Hámster chino) muestran que las estructuras porosas no son citotóxicas y tienen potencial para su aplicación en ingeniería de tejidos ortopédicos.