Cholesterol–PEG comodified poly (N-butyl) cyanoacrylate nanoparticles for brain delivery: in vitro and in vivo evaluations

Figures & data

Figure 1. (a) The in vitro release profiles of NPs. (b) Mean concentration of C6 in brains after IV administration of C6 formulations to rats at a dose of 0.5 mg/kg (mean ± SD, n = 3). **p < 0.01 versus the polysorbate-80 NPs group. ##p < 0.01 versus the CLS NPs group.

Figure 2. Cytotoxicity of (a) cholesterol, (b) PEG₂₀₀₀₀, (c) PBCA, (d) blank CLS-PEG NPs, and (e) C6 loaded CLS-PEG NPs in bEnd.3 cell line at different concentrations as assessed by MTT levels (mean ± SD, n = 5).

Figure 3. Effect of concentration (a) or the incubation time (b) on the cellular uptake of CLS-PEG NPs; Uptake (c) or uptake relative to control (d) of normal NPs (□), CLS NPs

or CLS-PEG NPs (▪) by bEnd.3 cells in the presence of different inhibitors at 37 °C for 2 h; (e) Transport of C6 CLS-PEG NPs with the concentration of 20 μg/mL (▪), 50 μg/mL (□) or 100

μg/mL across bEnd.3 cell monolayer at 37 °C by monitoring quantitatively the C6 in the basolateral chamber as the function of time and concentration; (f) P_app of C6 CLS-PEG NPs transport across bEnd.3 cell monolayer in the presence of different inhibitors (mean ± SD, n = 3). *p < 0.05, **p < 0.01 versus the control group.

Figure 4. Mean concentration-time profiles of C6 in organs after IV administration of free C6 solution (♦) (□), CLS NPs (▪) (▪) or CLS-PEG NPs (▴) (

) to rats at a dose of 0.5 mg/kg (means ± SD, n = 3). (a) plasma; (b) brain; (c) heart; (d) liver; (e) spleen; (f) lung; (g) kidney.

Table 1. Pharmacokinetic parameters of C6 after the IV administration of free C6 solution, CLS NPs and CLS-PEG NPs to rats at a dose of 0.5 mg/kg (means ± SD, n = 6).

	Coumarin-6
Parameters	Free drug (IV)	CLS NPs (IV)	CLS-PEG NPs (IV)
C0 (ng/ml)	828.4 ± 139.0	853.5 ± 143.8	906.6 ± 175.5
t1/2, λz (min)	60.1 ± 24.0	106.8 ± 21.7^b	275.6 ± 117.4^b
AUC0-t (μg·min/ml)	15.8 ± 2.4	22.9 ± 3.0^b	35.2 ± 4.4^b
AUC0-∞(μg min/ml)	16.0 ± 2.3	23.3 ± 3.2^b	39.9 ± 5.3^b
Vd, λz (l)	0.6 ± 0.3	0.6 ± 0.1	1.0 ± 0.4^a
CL (ml/min)	6.4 ± 0.9	4.4 ± 0.6^b	2.5 ± 0.4^b
F (%)	–	144.9	212.5

^ap < 0.05, ^bp < 0.01 versus the free drug group.

Table 2. Pharmacokinetic parameters of C6 in tissues and drug targeting index (DTI) to brain in three groups of rats after IV administration of free C6 solution, CLS NPs and CLS-PEG NPs at a dose of 0.5 mg/kg (means ± SD, n = 3).

Tissues	AUC0-t (μg·min/ml)	Cmax (ng/g)	Tmax (h)	DTI
Brain
Free drug	3.84 ± 0.21	45.64 ± 2.25	0.5	–
CLS NPs	27.69 ± 1.38^b	250.70 ± 15.79^b	0.5	5.04
CLS-PEG NPs	54.60 ± 4.21^b	388.01 ± 5.41^b	0.5	6.46
Heart
Free drug	8.45 ± 0.93	113.89 ± 16.48	0.25	–
CLS NPs	43.11 ± 3.58^b	403.73 ± 33.75^b	0.25	3.52
CLS-PEG NPs	39.13 ± 1.12^b	311.19 ± 33.38^b	0.5	2.08
Liver
Free drug	141.71 ± 13.25	2685.53 ± 356.67	0.25	–
CLS NPs	232.29 ± 16.69^b	3209.88 ± 535.98	0.25	1.13
CLS-PEG NPs	152.28 ± 6.76	2024.32 ± 134.43^a	0.25	0.48
Spleen
Free drug	271.02 ± 16.03	3848.83 ± 339.27	0.25	–
CLS NPs	659.91 ± 33.44^b	7003.94 ± 236.76^b	0.50	1.68
CLS-PEG NPs	491.57 ± 4.49^b	5940.80 ± 464.70^b	0.5	0.81
Lung
Free drug	63.88 ± 5.62	900.02 ± 67.86	0.5	–
CLS NPs	120.67 ± 4.82^b	872.21 ± 52.16	0.25	1.30
CLS-PEG NPs	63.93 ± 1.50	797.77 ± 71.77	0.5	0.45
Kidney
Free drug	2.56 ± 0.44	22.20 ± 1.91	0.5	–
CLS NPs	25.96 ± 1.54^b	218.55 ± 40.97^b	0.5	7.08
CLS-PEG NPs	27.75 ± 4.00^b	209.55 ± 32.30^b	0.5	4.93

^ap < 0.05, ^bp < 0.01 vs. the free drug group.