Swelling properties and drug release of new biocompatible POEGOPGMA hydrogels with VPTT near to the human body temperature

Abstract

Oligo (ethylene glycol) oligo (propylene glycol) methacrylates (OEGOPGMA) with different numbers of ethylene glycol (EG) and propylene glycol (PG) units in backbone were used for the preparation of new thermoresponsive POEGOPGMA hydrogels; EG6PG3MA and EG3PG6MA monomers were used; and three different POEGOPGMA hydrogels (PEG6PG3MA, PEG3PG6MA and P(EG6PG3/EG3PG6)MA copolymer with equal mol% of previous two) were fabricated from monomer–solvent (OEGOPGMA–water/ethanol) mixture by gamma radiation. Characterisation of the hydrogels was conducted by swelling, UV–Vis, scanning electron microscope, differential scanning calorimetry and in vitro biocompatibility (cytocompatibility and haemolytic activity) investigations. The modelling of drug release and diffusion characteristics was tested using cephalexin drug. For the first time, it was shown how to effectively tune the volume phase transition temperature (VPTT) values of the hydrogels by changing the ratio of more hydrophilic (EG) and more hydrophobic (PG) units in (EGPG) “block” pendant chains. The obtained hydrogels revealed the great potential for different biomedical applications not only due to the possibility to tune VPTT in the desired way but also due to the good biocompatibility and controlled drug delivery within the target temperature range.