Formulation and in vitro evaluation of 17-allyamino-17-demethoxygeldanamycin (17-AAG) loaded polymeric mixed micelles for glioblastoma multiforme

Glioblastoma multiforme (GBM) is the most common and aggressive malignant primary brain tumor in human. 17-Allylamino-17-demethoxy geldanamycin (17-AAG) is an inhibitor of heat shock protein 90 (HSP90). The highly lipophilic nature and selective targeting of tumor cells makes 17-AAG a promising candidate for therapy of GBMs but poor water solubility, short biological half-life and hepatotoxicity limited its clinical use. Polymeric mixed micelles composed of Pluronic® P-123 and F-127 (2:1 (w/w)) containing 17-AAG were prepared and characterized. Cellular uptake and in vitro cytotoxicity of the prepared micelles were determined in U87MG human glioblastoma cells. The particle size of 17-AAG loaded Pluronic® P-123 and F-127 mixed micelles was 22.2 ± 0.1 nm; drug loading was about 4.0 ± 0.5% (w/w) with 88.2 ± 3.1% (w/w) encapsulation efficiency. About 90% of drug was released from the nanoparticles over 8 days. Cellular uptake studies showed intracellular uptake of mixed micelles. Cytotoxicity study showed 5-fold increase (P < 0.05, n = 3) in the cytotoxicity of 17-AAG-loaded mixed micelles to free 17-AAG. Due to their targeting ability, size, high drug loading and controlled release behavior, 17-AAG loaded Pluronic® P-123 and F-127 mixed micelles might be developed as a delivery system for GBM treatment.