Hexanoyl-Chitosan-PEG Copolymer Coated Iron Oxide Nanoparticles for Hydrophobic Drug Delivery.

Nanoparticle (NP) formulations may be used to improve in vivo efficacy of hydrophobic drugs by circumventing solubility issues and providing targeted delivery. In this study, we developed a hexanoyl-chitosan-PEG (CP6C) copolymer coated, paclitaxel (PTX)-loaded, and chlorotoxin (CTX) conjugated iron oxide NP (CTX-PTX-NP) for targeted delivery of PTX to human glioblastoma (GBM) cells. We modified chitosan with polyethylene glycol (PEG) and hexanoyl groups to obtain the amphiphilic CP6C. The resultant copolymer was then coated onto oleic acid-stabilized iron oxide NPs (OA-IONP) via hydrophobic interactions. PTX, a model hydrophobic drug, was loaded into the hydrophobic region of IONPs. CTX-PTX-NP showed high drug loading efficiency (>30%), slow drug release in PBS and the CTX-conjugated NP was shown to successfully target GBM cells. Importantly, the NPs showed great therapeutic efficacy when evaluated in GBM cell line U-118 MG. Our results indicate that this nanoparticle platform could be used for loading and targeted delivery of hydrophobic drugs.