The Effect of Zinc Composition on the Degradation Rate of Magnesium Alloy for Developing Biodegradable Stent

In recent years, study on degradable biomaterials has become an essential part especially
in terms of medication. A lot of studies were carried out since decades ago on the treatment
of cardiovascular disease. The use of stent has been practices for the treatment of this
disease. Metallic stent might be permanent or biodegradable metals. Biodegradable
metals have break traditional thought that material for implant must be from inert metals.
Inert metals have several disadvantages for long time application and it needs to be
removed after vessel healing. Biodegradable stent is the solution for this problem. Stent
implanted could maintain its mechanical integrity during wall vessels healing and dissolve
after the healing process complete. Magnesium is suitable for biodegradable implant due
to its mechanical strength and properties. It is compatible and needed by human body for
biological reaction and as co-factor in enzymes. However in chloride abundant
environment like in human body fluid, it degrades faster therefore modification by
alloying is one of the recommended techniques to solve this problem. In this project, the
effect of zinc composition in Mg-Zn-Ca alloy on the biodegradability is investigated. Zinc
composition is varied between 0%, 1% and 2 %. Results show that the Mg-Zn-Ca alloy
with one weight percent zinc has the lowest weight loss. This indicate that the alloy has
the highest corrosion resistance and would prolong degradation rate of stent.