Investigation of transient mass transport induced deformation of PEGDA hydrogel in photocurable solution

Abstract

Abstract Hydrogels have attractive characteristics such as notable biocompatibility, outstanding hydrophilia and efficient mass transport (MT), which makes hydrogel suitable for tissue engineering scaffold materials. Stereolithography is a prevalent method to prepare hydrogel scaffold with complex structure. However, it is difficult to ensure dimension accuracy in printing complex hydrogel scaffold since solvents can migrate in gel and render MT behavior, which consequently induce deformation and dimensional inaccuracy of printed hydrogel. Little investigation of MT of gel in mixture like solution is conducted. Aiming to depict multiple solvents MT in gel, a model is established by mainly modifying the representation of free energy of mixing to the multi-component one. This model is feasible to describe concurrent multiple solvents migration and mechanical deformation for hydrogel in liquid mixtures, which fulfills understanding of multi-component MT. In this work, the transient MT behaviors of poly(ethylene glycol) diacrylate gel in its photocurable solution are investigated by the model. The numerical model is validated by experimental results and then applied to simulate free and confined MT process of the system. It is found that the deformation trend is not monotonous and total gel deformation can be regulated by adjusting printing time. The correspondence between numerical and experimental results proved that this model can promisingly illustrate multi-component MT induced deformation and provide instructions on improving dimensional accuracy for printing hydrogels.