Surface functionalization of PLGA nanoparticles for drug delivery

Since their introduction 40 years ago, poly(d,l-lactic-co-glycolic acid) (PLGA) polymers have been used commonly in tissue engineering and drug delivery systems. These polymers are currently a well-known biodegradable, biocompatible Food and Drug Administration (FDA)/European Medicines Agency (EMA) approved material for controlled release applications in industrial research and academia. As a carrier, PLGA improves drugs stability and drugs pharmacokinetics, which is beneficial to R&D of new delivery systems, like PLGA nanoparticles. When the surface of PLGA nanoparticles is modified by attaching functional groups, polymers, biomacromolecules, and other relevant molecules able to control interactions between the nanoparticles and biosurfaces, PLGA nanoparticles already meritorious attributes are further improved. Covered in this chapter is a review of several strategies for surface modification of PLGA nanoparticles, by means of noncovalent surface interactions, with an emphasis on the introduction of surfactants, proteins, peptides, antibodies, and nucleic acids, as well as additional relevant molecules. These modifications provide nanoparticles vectorization, modulate biodistribution, and improve in vivo performance by prolonging circulation time and increasing cellular uptake. Recent progress in functionalization of PLGA nanoparticles by surface modification are also reported, as well as a reflection on future directions and potentialities of drug delivery systems.