Polyphenolic compounds affect the long-term degradation behaviour of polymer and composite materials based on PCL, PLGA, and bioactive glass

Abstract

In recent years, the modification of biodegradable aliphatic polyesters with bioactive ceramics and plant-derived active agents has gained much attention in biomedical applications. They provide significant improvement in biological functionality of synthetic polymers. However, they simultaneously affect numerous physicochemical properties. In this work, for the first time, effect of incorporation of polyphenols (PPh) extracted from sage and sol-gel-derived bioactive glass (BG) particles, either alone or in combination, into poly(ε-caprolactone) (PCL) and poly(lactic-co-glycolide) (PLGA) was evaluated. BG particles were shown to accelerate degradation of materials based on slowly degrading polymer - PCL, while degradation of materials based on fast degrading polymer – PLGA was retarded. For PLGA-based composites, the formation of apatite layer and dissolution of alkaline ions from BG appear to have pivotal role in controlling degradation by providing protection from direct exposition to aqueous environment and neutralizing acidic by-products. PPh were shown to accelerate degradation of all studied materials. The following PPh-related factors can be involved in this process: wettability improvement, acid catalysis, plasticizing effect, and porosity formation. Our results highlighted the importance of considering the effect of commonly used polymeric modifiers on one of the most important properties of biomaterials used in tissue engineering and drug delivery - degradation.