Pluronic micelles represent a novel type of nanocarriers to increase solubility and circulation time of hydrophobic anti-cancer drugs, thereby enhancing therapeutic efficacy. Encapsulation of drugs influences the micelles' structural changes, which in turn alters pharmacokinetic behavior of the drug delivery system. In this work, small-angle neutron scattering (SANS) was used to probe the changes in the core/shell structure of pluronic P123 poly(ethylene oxid)20-poly(propylene oxide)70poly(ethylene oxide)20 PEO20-PPO70PEO20 block copolymer micelles as function of increasing paclitaxel (PTX) and pluronic concentration. Model-independent analyses along with cryogenic transmission electron microscopy (Cryo-TEM) confirmed that both pure and PTX encapsulated pluronic micelles were of spherical shape. Subsequent nuclear magnetic resonance (NMR) and Fourier transform infrared spectroscopy (FTIR) studies demonstrated that PTX incorporated in the PPO blocks of the micelle cores. However, increment in PTX concentration did not cause a significant change in micelles' core/shell structure but associated wit the appearance of the larger particles of the drug, an effect that was also confirmed by Cryo-TEM. At higher pluronic concentration and in the presence of constant PTX amount, the dimensional of micelles increased, which is hypothesized to be a consequence of the moderated hydrophobic environment promoting the interaction of PPO and PEO blocks.
Journal of the Taiwan Institute of Chemical Engineers
, Lin, K.
and Hammouda, B.
Small-Angle Neutron Scattering Studies of Microenvironmental and Structural Changes of Pluronic Micelles upon Encapsulation of Paclitaxel, Journal of the Taiwan Institute of Chemical Engineers, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=919848
(Accessed May 29, 2023)