Hydrogel modeling with molecular dynamcis

Hydrogel is a network of hydrophilic polymer chains, which solvent is especially water. Since hydrogel is easy to deform or manipulate and has biocompatibility, widely used in medicine or pharmaceutical industry. Typically contact lens, bio sensors, bio-prosthetics and medicine were made using hydrogel.

Generally, hydrogel contains a lot of waters, and has recoverability in swelling after it dried. It means the volume of the initial state of hydrogel and re-swelled state of hydrogel after drying is same. But if hydrogel is dried a lot, hysteresis occurs and volume does not return to the initial volume, after re-swelling.

This paper is represent the swelling and re-swelling simulation of hydrogel and some of experimental result. The molecular dynamics simulation is used to analysis hysteresis. The hysteresis can observe by molecular dynamics simulation, and is so, what is the cause. Simulation is conducted by GROMACS in full atomistic model, and the OPLS-aa was adopted as a forcefield. PEGDA(poly ethylene glycol diacrylate) is used in this research, and the hydrogel was constructed by creating a polymer network and applying some manipulations.