Shell cross-linked (SCL) thermoresponsive hybrid micelle consisting of a cross-linked thermoresponsive hybrid shell and a hydrophobic core domain was synthesized from poly(N-isopropylacrylamide-co-aminoethyl methacrylate)-b-polymethyl methacrylate (P(NIPAAm-co-AMA)-b-PMMA) amphiphilic block copolymers via a two-step process: micellization of P(NIPAAm-co-AMA)-b-PMMA in aqueous solution followed by cross-linking of the hydrophilic shell layer via the amidation reaction between the amine groups of AMA units and the carboxylic acid functions of 1,1’-ferrocenedicarboxylic acid. The SCL micelle showed reversible dispersion/aggregation in response to the temperature cycles through the lower critical solution temperature (LCST) of the thermoresponsive hybrid shell at around 36 oC, observed by turbidity measurements and dynamic light scattering (DLS). Besides the usage as an inorganic difunctional cross-linker, the inorganic ferrocene segment further endowed the SCL hybrid micelle with the anti-tumor efficacy, namely, the resultant SCL micelle exhibited a remarkable cytotoxic effect for HeLa cells with a very low IC50. The results showed that the SCL hybrid micelle developed in this study could be potentially used as an anti-tumor agent, which is unique compared to the conventional tumor therapy by using the anti-tumor drug loaded in the micellar core.
Journal: TechConnect Briefs
Volume: 3, Nanotechnology 2010: Bio Sensors, Instruments, Medical, Environment and Energy
Published: June 21, 2010
Pages: 296 - 299
Industry sectors: Advanced Materials & Manufacturing | Medical & Biotech