pH-sensitive polymeric nanoparticles of mPEG-PLGA-PGlu with hybrid core for simultaneous encapsulation of curcumin and doxorubicin to kill the heterogeneous tumour cells in breast cancer

Figures & data

Table 1. Characteristics of various formulations of nanoparticles (n = 3, mean ± SD).

			DLC (%)		DLE (%)
No	Polymer(mg)	Total drug (mg)(DOX + CUR)	CUR	DOX	CUR	DOX	Dh(nm)	Zeta potential
Blank NPs	200	–	–	–	–	–	211.2 ± 1.3	−25.4 ± 0.2
DOX-NP	200	2.5 + 2.5	–	2.28 + 0.34		95.00 ± 1.89	102.1 ± 0.4	−21.2 ± 0.6
CUR-NP	200	2.5 + 2.5	1.87 ± 0.41	–	76.91 ± 2.56	–	228.5 ± 1.5	−23.8 ± 0.3
DOXCUR-NP-1	100	5 + 5	2.61 ± 0.12	4.31 ± 0.14	57.73 ± 2.32	95.66 ± 3.35	56.2 ± 0.2	−5.2 ± 0.2
DOXCUR-NP-2	200	5 + 5	1.81 ± 0.04	2.28 ± 0.11	72.94 ± 3.45	95.80 ± 2.15	102.1 ± 0.1	−11.2 ± 0.1
DOXCUR-NP-3	300	5 + 5	1.42 ± 0.03	1.61 ± 0.13	87.86 ± 2.76	96.85 ± 1.36	380.7 ± 0.3	−16.2 ± 0.3
DOXCUR-NP-4	200	2.5 + 2.5	1.14 ± 0.05	1.18 ± 0.07	90.90 ± 4.21	96.76 ± 1.23	87.2 ± 0.1	−20.8 ± 0.3
DOXCUR-NP-5	200	5 + 5	1.91 ± 0.13	2.29 ± 0.19	80.30 ± 1.82	96.21 ± 1.34	103.4 ± 0.3	−11.7 ± 0.1
DOXCUR-NP-6	200	7.5 + 7.5	1.84 ± 0.21	6.61 ± 0.33	51.79 ± 2.68	94.51 ± 2.36	121.5 ± 0.2	−8.2 ± 0.6

Figure 1. Particles size distribution and transmitted electronic microscopy (TEM) of CUR-NPs (A, D), DOX-NPs (B, E) and CURDOX-NPs (C, F).

Figure 2. In vitro release profiles of DOX (A) and CUR (B) from nanoparticle formulation (CURDOX-NPs) or solution formulations (DOX-S or CUR-S) in pH7.4 PBS or pH5.0 acetate buffer.

Figure 3. Cytotoxicity of the different formulation against MCF-7/ADR after incubation of 24 h (A) and 48 h (B), and (C) the fluorescent distribution of DOX in MCF-7/ADR cells after treatment with different formulations for 4 h at 37 °C.

Figure 4. (A) microscopic images and (B) the relative spheroid volume of MCF-7/ADR spheroid after treatment with different formulations, and (C) the percentage of CD44⁺/CD24⁻ cells in MCF-7/ADR mammospheres after 3 days of treatment with various formulations. The dissociated MCF-7/ADR mammosphere cells were stained with anti-CD44-FITC and anti-CD24-PE antibodies.

Figure 5. In vivo anti-tumour efficacy of various formulations, (A) tumour growth of MCF-7/ADR cancer xenografts treated with saline (control), CUR-NPs, DOX-NPs and CURDOX-NPs at a total drug dose of 2.5 mg/kg; (B) the loss of body weight of tumour-bearing mice after treatment; (C) tumour image and (D) tumour weight excised at 17 days post-treatment (n = 6, p < .05).