Mesoscale modeling of controlled degradation and erosion in hydrogel films

Controlled degradation in hydrogel materials finds numerous applications from controlled drug release to sequential release of encapsulated cells for tissue engineering. While several chemical pathways can be used to introduce controlled degradation in hydrogels, the physical processes that occur during degradation are not well understood. Better understanding of the physics behind the polymer degradation process is essential to further develop applications. Herein, we present a Dissipative Particle Dynamics (DPD) based simulation approach for modeling controlled degradation and erosion in hydrogel films. Our recently developed framework allows us to model controlled degradation in films with first order kinetics for the degradation reaction. We track the evolution of the weight average degree of polymerization and occurrence of network disintegration (reverse gelation) in our simulations. We focus on the crossover between the surface and bulk erosion in hydrogel films. Our simulations help us to analyze impact of parameters such as crosslink density, system size and stoichiometric ratio of degradable bonds.