Polyester micro- and nanosized systems with therapeutic functionality

Abstract

Among the families of synthetic polymers, polyesters are very attractive for various medical, pharmaceutical, industrial and other purposes. The major applications include drug delivery systems, tissue engineering applications, resorbable sutures, and orthopaedic fixation devices. Polyester, poly (lactide-co-glycolide) (PLGA) is a copolymer of poly lactic acid (PLA) and poly glycolic acid (PGA). PLGA is biocompatible and biodegradable copolymer whit tunable properties. It is approved by FDA and has been comprehensively studied for the development of different systems and materials for commercial use and in research. It is often used for preparing controlled drug delivery devices. PLGA polymer particles allow the encapsulation of the medicament within the polymer matrix, where the basic requirement for the controlled and balanced release of the medicament in the body is its ideal spherical shape and narrow distribution of their sizes. Until now, different active substances have been successfully encapsulated within PLGA polymer matrix thus creating micro or nanosized systems with sustained release and different functionalities. One example is simultaneously encapsulation of water-soluble antioxidant (ascorbic acid, vitamin C) and poly(L-glutamic acid)-capped silver nanoparticles (AgNpPGA), within PLGA particles. These PLGA/AgNpPGA/ascorbic acid microspheres have been examined in terms of structural characteristics, morphology, stability, in vitro degradation, antimicrobial activity, cytotoxicity and induction of intracellular reactive oxygen species. They have demonstrated synergistic effects i.e. effective antioxidative and, at the same time, prolonged antimicrobial activity.