Use of biodegradable polymers in the field of medicine is booming. Polymers known as PLA (Polylactic Acid), PGA (Polyglycolide) and their copolymers can be used as surgical sutures, drug delivery carriers, bone fixing devices, tissue engineering scaffolds and so on due to their degradability, biocompatibility, mechanical properties and nontoxic to human body. The degrading nature of these biodegradable polymers avoids the second surgery for the removal of implants after providing its function.

This degrading nature can be tailored to fix the lifetime of the implants by the copolymer ratio, polymer blends, shape and size of the device according to the in vivo environment. Experimental studies on these medical implants are challenging to get the desired data due to excess time for the degradation and chemical and mechanical property change with the time.  Thus, computational models for polymer degradation have been developed over past decades by incorporating molecular weight reduction due to chain scission due to hydrolysis reaction and diffusion of the small polymer chains. These models shrink the time and are used to compare the experimental data to check the model accuracy.

We have developed a degradation model with cellular automation incorporating hydrolysis rate equation for polymer chain scission and FTCS (Forward Time Centered Space) scheme to remove the small polymer chains from the implants to observe the degradation behavior of polymeric implants. Degradation behavior of PLA predicted by our model is in agreement with the results published elsewhere in the literature.

Keywords: biodegradable polymers, medical implants, in vivo environment, hydrolysis reaction, cellular automation