Poly(D,L-lactic-co-glycolic acid) (PLGA) is a commonly used drug carrier due to its low toxicity, biodegradability, and biocompatibility. Typically, the characterization of PLGA nanoparticles involves determining their particle diameter, size distribution, morphology, and surface charge. However, the significance of the glass transition temperature (Tg) of nanoparticles is often overlooked, despite Tg being an important parameter of PLGA nanoparticles impacting the drug release behavior of drug delivery nanoparticles. In particular, the surrounding interface can affect the Tg of polymeric nanoparticles. As such analysis of PLGA nanoparticles in relevant solutions for drug delivery is important to understand. Nanoparticles in biological fluids form a dynamic "protein corona" that alters their surface characteristics and increases their size. Studies show the Tg of PS nanoparticles varies with suspension medium—showing strong, weak, or negligible size correlation in water, ionic liquid, and glycerol, respectively—due to differences in interfacial viscosity. While the Tg of PLGA nanoparticles has not yet been linked to protein corona formation, further research is needed to explore this potential relationship. In this study, model PLGA nanoparticles are prepared and the Tg of the PLGA nanoparticles suspended in blood plasma, protein solution, water, and PBS is measured using modulated DSC.
