Synthesis of novel photoactive degradable polymers with potential in biomedical applications

Abstract

Synthetic biopolymers have received considerable attention in recent years in view of their tremendous potential in the fields of medicine and tissue engineering applications. Star-shaped biopolymers containing multi arms radiating from a core center represent an appealing candidate as drug carrier for drug delivery application. In this study, a range of novel photoactive star-shaped and linear biodegradable polymers are synthesized by ring-opening and condensation polymerization techniques respectively. The star-shaped polymers were prepared using porphyrin, lactide, caprolactone, and glycolide as building blocks. The synthesized polymers generally varied in terms of not only composition and but also molecular weight controlled by the feed ratios of the monomers to initiator in their reactions. A comprehensive study is conducted to determine the effect of reaction parameters to the properties of the polymers, based on a range of analytical techniques such as FTIR, NMR, GPC, UV-Vis, fluorescence, WAXRD, DSC, TG, and DMA. Besides, extensive work is carried out to evaluate their performance in various potential applications such as drug delivery and shape memory. For the drug delivery study, a few of the star-shaped polymers are chosen and fabricated with anti-cancer drugs via an emulsion and solvent evaporation technique. The resulting drug loaded nanoparticles are investigated in terms of drug loading efficiency, drug release profile as well as other useful physical and chemical properties. For the shape memory study, novel linear and star-shaped polymers are prepared in different molecular compositions. The shape memory effect of the films obtained from solvent casting is studied by means of DSC, XRD, DMA and shape memory measurements over cyclic mechanical tests. The sample polymers are also subjected to a cytotoxicity assay in order to gain an insight about their biocompatibility.