Doxorubicin Hydrochloride-Loaded Nonionic Surfactant Vesicles to Treat Metastatic and Non-Metastatic Breast Cancer

Abstract

Doxorubicin hydrochloride (DOX) is currently used to treat orthotropic and metastatic breast cancer. Because of its side effects, the use of DOX in cancer patients is sometimes limited; for this reason, several scientists tried designing drug delivery systems which can improve drug therapeutic efficacy and decrease its side effects. In this study, we designed, prepared, and physiochemically characterized nonionic surfactant vesicles (NSVs) which are obtained by self-assembling different combinations of hydrophilic (Tween 20) and hydrophobic (Span 20) surfactants, with cholesterol. DOX was loaded in NSVs using a passive and pH gradient remote loading procedure, which increased drug loading from ∼1 to ∼45%. NSVs were analyzed in terms of size, shape, size distribution, zeta potential, long-term stability, entrapment efficiency, and release kinetics, and nanocarriers having the best physiochemical parameters were selected for further in vitro tests. NSVs with and without DOX were stable and showed a sustained drug release up to 72 h. In vitro studies, with MCF-7 and MDA MB 468 cells, demonstrated that NSVs, containing Span 20, were better internalized in MCF-7 and MDA MB 468 cells than NSVs with Tween 20. NSVs increased the anticancer effect of DOX in MCF-7 and MDA MB 468 cells, and this effect is time and dose dependent. In vitro studies using metastatic and nonmetastatic breast cancer cells also demonstrated that NSVs, containing Span 20, had higher cytotoxicity than NSVs with Tween 20. The resulting data suggested that DOX-loaded NSVs could be a promising nanocarrier for the potential treatment of metastatic breast cancer.

Figure 1

Schematic representation of DOX pH remote loading through the niosomal membrane (A) and physicochemical characterization of empty and DOX-NSV1grad and DOX-NSV6grad (B). Statistical significance was setup at *p < 0.05 and was calculated by comparing the average sizes of NSV1grad and DOX-NSV1grad. Results are the average of three independent experiments ± S.D. (n = 3).

Figure 2

TEM images of empty and DOX-NSV1grad (top), and empty and DOX-NSV6grad (bottom). Images are representative of three independent experiments.

Figure 3

Serum stability of NSV1grad (A) and NSV6grad (B). Results are the average of three independent experiments ± S.D. (n = 3). The p values of <0.05 (*), <0.01 (**), and <0.001 (***), with respect to other DOX-NSVs.

Figure 4

(A) ΔBS (A, left) and ΔT (A, right) for NSV1grad and DOX-NSV1grad. (B) ΔBS (B, left) and ΔT (B, right) for NSV6grad and DOX-NSV6grad. The image is representative of three independent experiments ± S.D. (n = 3).

Figure 5

Kinetic destabilization profiles for NS1grad and DOX-NSV1grad (A) and NSV6grad and DOX-NSV6grad (B). The image is representative of three independent experiments ± S.D. (n = 3).

Figure 6

Schematic representation of DOX released from NSVsgrad in Hepes or Serum/Hepes (A), kinetics release of DOX from NSV1grad (B), and NSV6grad (C). Results are the average of three independent experiments ± S.D. (n = 3). The p values of <0.05 (*), <0.01 (**), and <0.001 (***), with respect to Hepes.

Figure 7

MCF-7 cell viability upon incubation times at 24 (A), 48 (B), and 72 h (C) with different concentrations of free DOX, DOX-NSV1grad, and DOX-NSV6grad. Results are the average of three independent experiments ± S.D. (n = 3). The statistical analysis of cytotoxicity data is available in the Supporting Information (Table S2).

Figure 8

MDA MB 468 cell viability upon incubation times at 24 (A), 48 (B), and 72 h (C) with different concentrations of free DOX, DOX-NSV1grad, and DOX-NSV6grad. Results are the average of three independent experiments ± S.D. (n = 3). The statistical analysis for the cytotoxicity data is available in the Supporting Information (Table S2).

Figure 9

Confocal microscopy analysis of rhodamine-DHPE NSV6grad at 6 and 24 h post incubation with MCF-7 and MDA MB 468 cells. The image is representative of three independent experiments (n = 3).