A Reaction-Diffusion Model for Capturing Mass Loss and Microstructure Evolution in Enzymatic Degradation of...

Area of Science:

• Biomaterials Science
• Polymer Chemistry
• Computational Modeling

Background:

• Semicrystalline bioresorbable polymers' microstructure dictates biomedical performance.
• Crystalline content impacts mechanical stability and degradation.
• Existing models lack microstructural evolution and state-selective degradation insights.

Purpose of the Study:

• To develop a model capturing microstructural evolution during enzymatic degradation.
• To investigate state-selective degradation mechanisms in bioresorbable polymers.
• To explore the impact of film thickness on degradation dynamics.

Main Methods:

• Developed a 1D partial differential equation model treating crystalline and amorphous states distinctly.
• Calibrated the model using poly(ε-caprolactone) (PCL) degraded by *Candida antarctica* lipase in vitro.
• Performed parameter uncertainty and sensitivity analyses.

Main Results:

• The model accurately reproduced experimental weight-loss and crystallinity decline.
• Amorphous catalytic rate was identified as the dominant degradation driver.
• Thin films showed reaction-limited degradation, while thicker films were transport-influenced.

Conclusions:

• The model effectively simulates enzymatic degradation of PCL, considering microstructural changes.
• Film thickness significantly influences degradation rates and structural evolution.
• This model aids in predicting degradation behavior and optimizing material design without extensive experiments.