Abstract
Treatment of cancer patients with taxane-based chemotherapeutics, such as paclitaxel (PTX), is complicated by their narrow therapeutic index. Polymeric micelles are attractive nanocarriers for tumor-targeted delivery of PTX, as they can be tailored to encapsulate large amounts of hydrophobic drugs and achiv prolonged circulation kinetics. As a result, PTX deposition in tumors is increased, while drug exposure to healthy tissues is reduced. However, many PTX-loaded micelle formulations suffer from low stability and fast drug release in the circulation, limiting their suitability for systemic drug targeting. To overcome these limitations, we have developed PTX-loaded micelles which are stable without chemical cross-linking and covalent drug attachment. These micelles are characterized by excellent loading capacity and strong drug retention, attributed to ∏-∏ stacking interaction between PTX and the aromatic groups of the polymer chains in the micellar core. The micelles are based on methoxy poly(ethylene glycol)-b-(N-(2-benzoyloxypropyl)methacrylamide) (mPEG-b-p(HPMAm-Bz)) block copolymers, which improved the pharmacokinetics and the biodistribution of PTX, and substantially increased PTX tumor accumulation (by more than 2000%; as compared to Taxol or control micellar formulations). Improved biodistribution and tumor accumulation were confirmed by hybrid μCT-FMT imaging using near-infrared labeled micelles and payload. The PTX-loaded micelles were well tolerated at different doses, while they induced complete tumor regression in two different xenograft models (i.e., A431 and MDA-MB-468). Our findings consequently indicate that ∏-∏ stacking-stabilized polymeric micelles are promising carriers to improve the delivery of highly hydrophobic drugs to tumors and to increase their therapeutic index.
Original language | English |
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Pages (from-to) | 3740-3752 |
Number of pages | 13 |
Journal | ACS Nano |
Volume | 9 |
Issue number | 4 |
DOIs | |
Publication status | Published - 28 Apr 2015 |
Externally published | Yes |
Keywords
- drug targeting
- nanomedicine
- paclitaxel
- polymeric micelles
- ∏-∏stacking