Paclitaxel-betulinic acid hybrid nanosuspensions for enhanced anti-breast cancer activity.

Paclitaxel-betulinic acid hybrid nanosuspensions (PTX-BA-NP) with increased anti-breast cancer activity were developed. The resultant nanosuspensions (NP) had a mean particle size of 282.54 ± 5.4 nm, a polydispersity index of approximately 0.242 ± 0.02, a zeta potential of -19.7 ± 0.19 mV and a redispersibility index of 103.3 ± 0.01%. The cumulative dissolution percentage of PTX coarse powder and PTX-BA-NP dried powder at 60 min were 15.4% and 90.8%, respectively. MCF-7 cell-based testing showed that treatment with PTX-BA-NP led to more PTX-BA-NP accumulation in the cytoplasm of breast cancer cells, less cell cycle arrest in the G2-M phase, more cell cycle arrest in the G0-G1 phase, more apoptosis-induced cell death and stronger inhibition of cell migration than paclitaxel nanosuspensions (PTX-NP). Biodistribution studies showed that tumor accumulation levels at 12 h in the PTX-BA-NP group were approximately 2.67- and 2.33-fold higher than the levels in the Taxol® and PTX-NP groups, respectively. In vivo antitumor efficacy demonstrated that PTX-BA-NP exerted the strongest tumor inhibition among the four groups, with a tumor inhibition rate of 47.79 ± 2.28%, followed by PTX-NP (35.05 ± 5.55%), Taxol® (22.67 ± 6.01%) and betulinic acid nanosuspension (BANP) (14.38 ± 6.02%). These findings indicate that PTX-BA-NP holds great promise for breast cancer therapy.