Novel, biocompatible and photo crosslinkable polymeric networks based on unsaturated polyesters: Optimization of the network properties

Abstract

Using aliphatic, unsaturated polyester macromers to develop in situ forming devices applicable in drug delivery and/or tissue engineering applications is a rapidly growing field. Such devices can be formed upon crosslinking of the unsaturated bonds via different initiation systems. Here, determination of optimal levels of the network components consisting the macromer i.e. poly (Hexamethyelene carbonate)-co-fumarate (PHMCF) and photo-initiation system comprising of camphorquinone (CQ) and its ratio to amine accelerator on final networks properties will be reported. Dimethylamino methyl ethylacrylate (DMAMEA) was used as the amine. Two set of experiments with varying concentrations of CQ (0.5-1.5 wt. %) with and without amine (0.5-1.5 wt. %) were designed. The samples were photo cured after thorough mixing of the compositions using blue light (500 mW/cm2) irradiation for 200 seconds. Degree of conversion (DC %) was determined using FT-IR spectroscopy before and after curing. According to the results, PHMCF macromers can be regarded as self-crosslinkable ones according to the degree of conversion (DC %) results with no need to amine. Network characterizations were also accomplished by equilibrium swelling experiments, aqueous and organic sol fraction studies and rheological studies to determine crosslink density. Biocompatibility studies including direct contact and MTT assay were also elucidated lower toxicity profile for the samples (without DMAMEA) without any significant reduction in the networks characteristics. Results were also guaranteed using a suggested kinetics approach. Statistically, it was confirmed that 1 %wt of CQ (without amine) will provide the lowest swelling ratio and sol fraction as a sign of higher degree of conversion without any deterioration in the biocompatibility. © 2009 Springer Berlin Heidelberg.