A set of low polydispersity diblock copolymers HO-PCLn-b-PEG32-RX (n= 51, 67, 109, R= -O(CH2)3S(CH2)2-, X= -CO2Na, -SO3Na) were synthesized for comparative studies of micelle formation and relative stability in aqueous solutions from HO-PCLn-b-PEG32-CH2CH=CH2 by thiol-ene click chemistry . Narrow size distribution micelles with spherical shapes were characterized by dynamic light scattering (DLS) and cryo-transmission electron microscopy (cryo-TEM). Our working hypothesis is that the stability of aqueous dispersions of micelles can be increased by placing ionic end groups on PEG which gives electrically charged micelle corona that both increase interactions of the micelle with the aqueous environment and inhibit aggregation of micelles through electrostatic repulsions. Micelles from [PCLn-b-PEG32-RCO2]-Na+ and [PCLn-b-PEG-RSO3]-Na+ with negatively charged corona showed a significant increase in the stability compared to the parent HO-PCLn-b-PEG32-CH2CH=CH2 micelles with a neutral corona. Negatively charged corona stabilize relatively large hydrophobic cores for micelles from diblock copolymers with high hydrophobic to hydrophilic ratios which provides a general approach to increase the drug loading capacity for a micelle carriers.

Effects of charged corona on the stability of aqueous dispersions of PCL-<i>b</i>-PEG diblock copolymer micelles

247th National Meeting (2014)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.

Effects of charged corona on the stability of aqueous dispersions of PCL-b-PEG diblock copolymer micelles