Undergraduate Research Journal
Undergraduate Research Journal
Undergraduate Research Journal
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Rate of Degradation of Magnesium Alloy Screws in<br />
Phosphate Buffered Saline<br />
Tejas Patel, Huinan Liu, Maria Iskandar<br />
Department of Bioengineering<br />
University of California, Riverside<br />
ABSTRACT<br />
Current metallic orthopedic implants include stainless steel, titanium, and cobalt-chromium<br />
based alloys. Although these materials are effective in securing fractures, they also possess many<br />
disadvantages. They can slowly break apart into toxic ions which can lead to local inflammation.<br />
Moreover, they require a second surgical procedure for removal after they have served their purpose.<br />
Magnesium (Mg) alloys are a great alternative to these metallic implants. They are biocompatible,<br />
biodegradable, and can promote new bone growth. Moreover, their light weight and mechanical<br />
resemblance to bone make them an ideal material for orthopedic implant applications. However,<br />
their rapid degradation in the physiological environment is a major obstacle. In this study, pure<br />
Mg, AZ31 (3% aluminum, 1% zinc), and Mg-4Y (4% yttrium) were tested to determine the rate of<br />
degradation. Each screw was submerged in 3mL of phosphate buffered saline (PBS). 1 x PBS was<br />
used for the first 15 days of the study. 10 x PBS was used from 17 days through 31 days. Of the<br />
three metals, Mg-4Y was the first to completely degrade. Large pieces began to break off making it<br />
the fastest degrading screw we tested. AZ31 showed the best improvement in degradation, followed<br />
closely by pure Mg.<br />
MentorS<br />
Faculty Mentor: Huinan Lui (right)<br />
Graduate Student Mentor: Maria Iskandar<br />
Department of Bioengineering<br />
Our research goal is to develop fully biodegradable medical implants that will<br />
eliminate the need for secondary surgeries for implant removal, funded by a National<br />
Science Foundation BRIGE award. Tejas worked with my graduate student Maria<br />
Iskandar as a team to study the degradation of a group of novel magnesium-based resorbable<br />
interference screws in physiological fluids. His results provide implant guidelines for designing nextgeneration<br />
biodegradable implants. Tejas is self-motivated and determined to accomplish the project<br />
goal. I am impressed by Tejas’s research capability, hard work, and professional communication<br />
skills. He presented his research results at the UCR Symposium for <strong>Undergraduate</strong> <strong>Research</strong>,<br />
Scholarship, and Creative Activity, and his work will also lead to a research article to be published in<br />
a scientific journal. In my observation of Tejas, I know that his initiative, enthusiasm, and hard work<br />
prepares him well for success in future research. He asks important research questions, and thinks<br />
about them actively. He always participates our group meetings, and presents his research progress in<br />
a professional and scientific way. Tejas has learned the exciting aspects of scientific research and has<br />
decided to apply for graduate school.<br />
A U T H O R<br />
Tejas Patel<br />
Bioengineering<br />
Tejas Patel, a fourth year<br />
Bioengineering major, transferred<br />
to UCR in 2010 from American<br />
River College in Sacramento. He<br />
joined the Liu <strong>Research</strong> Group in<br />
the summer of 2011 where he works<br />
on the degradation of magnesium<br />
alloy screws used for graft fixation<br />
during ACL reconstructive surgery.<br />
He focuses his research on pure<br />
magnesium, AZ31, and Mg-4Y to<br />
determine the rate at which they<br />
degrade in phosphate buffered<br />
saline. This experience sparked Tejas’<br />
interest in research and he will pursue<br />
a Master’s degree in Bioengineering.<br />
Tejas Patel thanks Dr. Huinan Liu and<br />
Maria Iskandar for their guidance and<br />
support.<br />
A copy of this paper in its entirety can be found online at<br />
www.ugr.ucr.edu in Volume VI.<br />
6 2 U C R U n d e r g r a d u a t e R e s e a r c h J o u r n a l