Poly(vinyl alcohol) (PVA) in hydrogels, a molecular perspective

One of the main goals in the field of regenerative medicine is the construction of complex 3D scaffolds that can repair damaged tissue. The polymer chosen for this study is poly(vinyl) alcohol (PVA), widely used in tissue engineering [1]. PVA can be tailored for mechanical properties and has high-performance degradation kinetics. Its morphology and shape can be easily manipulated to improve vascular conduction and tissue induction. PVA is an excellent candidate for the manufacture of hydrogels with high tissue repair capacity and low cytotoxicity. We studied the water-polymer interaction of the material using a molecular dynamics (MD) approach for the calculation of solvation free energy and other parameters. For the modeling and data analysis, we used the high-performance computational software, Gromacs. Hydrogels were prepared at 10, 20, and 35 WT PVA. The hydrogel morphology and pore size were analyzed by SEM. Pore diameter tended to be larger when swelling in water than in PBS. The end-to-end distance of the MD simulated 30-mer was found to be larger in pure water than in the presence of ions. The trend can partially explain the experimental results of pore size. We also found an important change in solvation free energy when the polymer changes from an open to a closed conformation in water.