Pharmacokinetics and in vitro and in vivo delivery of sulforaphane by PCL–PEG–PCL copolymeric-based micelles

Figures & data

Table 1. Molecular characterics of the synthesized copolymers.

Copolymer	CL/EG feed	Mn (Da)^a	Mw (Da)^a	PdI^b	Tm (°C) ^c	DPPEG	DP^dPCL
1	0.5	8940	9731	1.08	58.68	136.36	32.68
2	1	10,901	11,876	1.09	61.23	136.36	51.48
3	2	14,532	15,890	1.09	59.76	136.36	86.64
4	4	17,432	18,342	1.05	60.87	136.36	108.13
5	5	18,976	21,321	1.12	59.78	136.36	134.22

^a Determined by GPC analysis using narrow molecular weight polystyrene standards.

^b M_w/M_n=Polydispersity index of the polymers (PdI) determined by GPC analysis.

^c Calculated from the first run of DSC as half of the extrapolated tangents.

^d DP: degree of polymerization.

Figure 1. (a) AFM image of SF-loaded spherical core shell micelles; (b) particle size distribution; (c) zeta potential.

Table 2. Properties of SF-loaded PCL–PEG–PCL micelles.

Micelles	SF/copolymer mass ratio	EE (%)	DL (%)	Size (nm)	Zeta	PDI	Stability
6	0	0	0	99.07	−2.01	0.143	Yes
7	0.05	41.8	10.9	102.6	−4.8	0.125	Yes
8	0.1	57.3	11.4	103.9	−2.7	0.137	Yes
9	0.25	87.1	19.33	114	−7.57	0.141	Yes
10	0.5	66.1	17.9	237.8	−3.8	0.312	Yes
11	0.75	53.9	18.1	345.7	−3.4	0.365	No
12	1	49.3	17.3	389.09	−2.5	0.423	No

Table 3. Characterisistic of micelles from the synthesized copolymers.

Micelles	CL/EG feed	EE (%)	DL (%)	Size (nm)	Zeta
14	0.5	41.39	10.9	96	−4.8
15	1	50.54	12.31	101	−5.1
16	2	62.12	14.09	98.09	−6.43
17	4	73.05	17.1	112	−5.12
18	5	87.1	19.33	114	−7.57

Figure 2. (a) The release profiles of SF from SF-PCL–PEG–PCL micelles in different release media. (b) The release profiles of SF from SF-PCL–PEG–PCL micelles in different copolymers composition.

Figure 3. Cytotoxicity of free SF, PCL–PEG–PCL micelles and SF-loaded micelle against MCF-7, MCF10A and 4T1 cells. The cells were incubated with SF-loaded micelle (SF concentration 1–30 μmol/L) for 48 and 72 h at 37° C each bar represents the mean of five measurements ± SD.

Figure 4. (a) Statistical analysis of flow cytometry results show total apoptosis and live cell percentages in 4T1 cells. The values represent mean ± SD. *P < 0.0001, #P < 0.0001, and +P < 0.0001 indicate significant difference between PCL–PEG–PCL, free SF, and SF/PCL–PEG–PCL, respectively. (b) The apoptosis induction by SF at [PCL–PEG–PCL] micelles (D), free SF (C), [PCL–PEG–PCL] Micelles (B) and negative control (PBS) (A) on 4T1 cell line.

Figure 5. (a) Statistic analysis of gene expression in MCF-7 cells after 48 h treatments with 20 μmol/L of free SF, PCL–PEG–PCL micelles and SF loaded PCL–PEG–PCL. Each experiment was repeated three times. (b) Effects of PCL–PEG–PCL micelle and SF-loaded PCL–PEG–PCL micelle on the level of nitric oxide in NR8383 cells. Data represents the mean ± standard error of The mean of four experiments (P < 0.01 is significantly different from the LPS); (c) Hemolytic test on PCL–PEG–PCL micelle and SF-loaded PCL–PEG–PCL micelle. Data represent the mean ± standard error of the mean of three experiments (P < 0.01 compared to saline group); (d) Antitumor effect of free SF, PCL–PEG–PCL micelles and SF-loaded PCL–PEG–PCL in 4T1 tumor bearing mice. Mice were administered free SF (•) and SF-loaded micelle (▪) andPBS (▴) i.v at the equivalent 30 mg/kg SF.

Figure 6. Comparison of in vivo plasma concentration vs. time profiles of the different SF formulations. All values reported are the mean ± SD (n = 5).

Table 4. Pharmacokinetic parameters of SF following single oral administration of SF aqueous solution and SF-loaded micelles, in rats (n = 5).

Pharmacokinetic parameters	SF aqueous solution	SF-loaded nanoparticles
Dose (mg/kg)	30	30
AUC0–t (h ng/mL)	8.231 ± 0.872	438.695 ± 1.321
AUC0–inf (h ng/mL)	8.3425 ± 1.564	465.87 ± 34.2
Cmax (ng/mL)	15 ± 0.203	45 ± 0.123
Tmax (h)	0.5	4
Ke (1/h)	0.61 ± 0.021	0.12 ± 0.034
t1/2 (h)	1.12 ± 0.112	5.98 ± 0.118
Vd (L/kg)	9420.132 ± 2221.3	909.123 ± 252.1
Cl (L/h/kg)	5434.132 ± 2312.1	101.145 ± 8.76

Values reported as mean ± SD (n = 5). AUC: area under the plasma concentration–time curve; C_max: peak concentration; T_max: time to reach peak concentration; K_e: constant of elimination; t_1/2: mean half-life; V_d: apparent volume of distribution; Cl: clearance.

Significantly different of free SF (P < 0.01).

Significantly different of SF from nanoparticles (P < 0.01).