Self-assembly and paclitaxel loading capacity of α-tocopherol succinate-conjugated hydroxyethyl cellulose nanomicelle

A series of α-tocopherol succinate-conjugated hydroxyethyl cellulose (HEC-TOS) polymers were synthesized in this study. The weight percentages of TOS in HEC-TOS were varied from 15 to 36 % by adjusting the weight ratios of TOS to HEC from 1:4 to 5:2. The HEC-TOS polymers exhibited typical properties of amphiphilic polymers and were able to self-assemble into spherical nanomicelle in aqueous solution as revealed by TEM. The micelle sizes and critical micelle concentrations (CMC) of HEC-TOS conjugates were correlated with their molecular structures and were in the range of 24.5–115.1 nm and 16–99 μg/ml, respectively. Paclitaxel (PTX) was encapsulated into the core of HEC-TOS micelle by sonication-dialysis method. The highest loading concentration of PTX in micelle was 315 mg/ml, which was about 50 times higher than that in water (6 mg/l). The in vitro study showed that PTX was continuously released from PTX-loaded micelle in phosphate buffered saline (PBS) medium for 108 h.