PRODUCTION OF BIODEGRADABLE HIGHLY POROUS ZN-MG ALLOY FOAM BY SPACE HOLDER METHOD
GULBERK DEMIR *
Bilecik Seyh Edebali University, Institute of Graduate, Department of Molecular Biology and Genetics, Bilecik, Turkey.
ILVEN MUTLU
Istanbul University-Cerrahpasa, Engineering Faculty, Department of Metallurgical and Materials Engineering, Istanbul, Turkey.
*Author to whom correspondence should be addressed.
Abstract
Porous scaffolds is very important for tissue engineering applications. In particular, metallic scaffolds are being studied. Zinc is an alternative to Mg as a biodegradable metal. Zn can have an appropriate biodegradation rate than Mg. Recent studies confirm that the Zn is nontoxic and can provide osseointegration. Zn alloys have a low melting temperature, machinability and reactivity. In this work, biodegradable Zn alloy was manufactured for scaffold and temporary implant applications. Samples with interconnected porous structures were manufactured by the powder metallurgy based space holder method. Zn-Mg alloys were manufactured by using Zn, Mg powders. Powder mixtures were ball-milled. Carbamide powders were used as a space holder. Samples were immersed into the water and then the space holder was removed. Sintering was done at 400ºC for 1 hour under argon. The results showed that corrosion rates of the samples were lower than the Mg alloys. Biodegradation was also investigated by weight loss and metal release measurements. Weight loss was about 2-4%. Metal release amount was lower than the daily upper limit of 15 mg/day for the Zn. Alloying was improved the strength of Zn. Osseointegration and biocompatibility properties were improved with Mg. The modulus of elasticity was increased by 24% with the increase of Mg content.
Keywords: Zn alloy, biodegradable implant, tissue engineering, powder metallurgy, temporary implant