Computer Simulation of Polymer Chain Scission in Biodegradable Polymers

Biodegradable polymers are used in medical devices such as fixation plates, sutures, or micro particles for the controlled release of drugs. Typical polymers are poly lactic acid (PLA), poly glycolic acid (PGA), and poly caprolactone (PCL). During degradation, the ester bonds within polymer chains are cleaved due to the hydrolysis reaction in the presence of water. It has been suggested that both chain end scission and random chain scission occur [1] and mathematical models have been able to fit experimental data with assumptions of random scission [2-4], end scission [5], or a combination of both [6]. In random scission, every bond in a polymer chain is assumed to be equally susceptible to hydrolysis. In chain end scission, the final bond in a chain is cleaved resulting in the production of a monomer.