Capturing the Real-Time Hydrolytic Degradation of a Library of Biomedical Polymers by Combining Traditional Assessment and Electrochemical Sensors

We have developed an innovative methodology to overcome the lack of techniques for real-time assessment of degradable biomedical polymers at physiological conditions. The methodology was established by combining polymer characterization techniques with electrochemical sensors. The in vitro hydrolytic degradation of a series of aliphatic polyesters was evaluated by following the molar mass decrease and the mass loss at different incubation times while tracing pH and L-lactate released into the incubation media with customized miniaturized electrochemical sensors. The combination of different analytical approaches provided new insights into the mechanistic and kinetics aspects of the degradation of these biomedical materials. Although molar mass had to reach threshold values for soluble oligomers to be formed and specimens' resorption to occur, the pH variation and L-lactate concentration were direct evidence of the resorption of the polymers and indicative of the extent of chain scission. Linear models were found for pH and released L-lactate as a function of mass loss for the Llactide-based copolymers. The methodology should enable the sequential screening of degradable polymers at physiological conditions and has potential to be used for preclinical material's evaluation aiming at reducing animal tests.

Automated summary

An innovative methodology combining polymer characterization techniques and electrochemical sensors was developed to assess degradable biomedical polymers in real-time under physiological conditions. The study provided new insights into the mechanistic and kinetics aspects of the degradation process, with pH variation and L-lactate concentration serving as direct evidence of polymer resorption and chain scission extent. Linear models were found for pH and released L-lactate as a function of mass loss for the Llactide-based copolymers, indicating the potential for preclinical material evaluation and reduction of animal testing.