Synthesis and characterization of polyethylene glycol dimethacrylate hydrogels for biomedical application

Photo-polymerized polyethylene glycol dimethacrylate (PEGDMA) scaffolds were synthesized using two macromolecular monomers of 750 and 550 number average molecular weight. Variation in chain length of macromolecular monomers visibly influenced viscoelastic properties of the compositions, exhibiting an increase in shear storage and loss modulus in PEGDMA 750 hydrogels. Furthermore, water content in the pre-polymerization mixture was a main factor determining physical appearance of the samples, where increase in water content resulted in polymerization induced phase separation, demonstrated by opaqueness of preparations containing 60 and 75% (w/w) of H2O. In addition to this, swelling, gel fraction, compression and rheological measurements are found to be influenced by the amount of water incorporated in the hydrogels, resulting in the increased distance between polymer chains within the network. Furthermore this resulted in an apparent decrease in viscoelastic and mechanical properties of compositions, as well as in lowering their crosslinking density and compressive strength. Preliminary cytotoxicity results show no toxicity of the samples with approximately 80% cell viability after 24 h exposure of MC3T3-E1 Subclone 4 cells to the hydrogels, thus indicating that these materials could be potentially applied in the biomedical arena.