Oral and tumor-targeting mixed micelles based on pegylated biotin and chitosan-based conjugate for breast cancer treatment

Oral drug delivery with tumor-targeting treatment persists as a challenge. In this study, a mixed polymeric micelle (PM) delivery system was designed to overcome the barriers to oral administration for tumor-targeting delivery of paclitaxel (PTX) for breast cancer treatment. D-α-Tocopheryl polyethylene glycol 1000 succinate-modified carboxymethyl chitosan-rhein (TCR) conjugate and Biotin-polyethylene glycol 2000-Biotin (BPB) conjugate were mixed to form TCR-BPB PMs. The particle size and polydispersity index of optimized PTX-loaded TCR-BPB PMs (PTX/TCR-BPB PMs) was 195.90 ± 7.63 nm and 0.08 ± 0.00, with a drug-loading capacity of 41.94 ± 2.47 %. In simulated gastroenteric fluid and blood environments, the PMs presented a sustained-release manner. PTX/TCR-BPB PMs were taken up by Caco-2 and 4T1 cells and displayed strong cytotoxicity in a time- and concentration-dependent manner. PTX/TCR-BPB PMs significantly improved intestinal absorption of PTX. The pharmacokinetics, tissue distribution, and in vivo imaging indicated that PTX/TCR-BPB PMs could enhance oral bioavailability of PTX, prolong the retention time of PTX in the blood, and enhance PTX tumor-targeting ability. PTX/TCR-BPB PMs enhance the antitumor efficacy of PTX and reduce its toxicity in normal organs. Therefore, TCR-BPB PMs are expected to serve as delivery carriers for the oral and tumor-targeting delivery of hydrophobic antitumor drugs.