Arginine-stabilized mPEG-PDLLA (50/50) polymeric micelles of docetaxel by electrostatic mechanism for tumor-targeted delivery

Figures & data

Figure 1. IR spectrum of D, L-lactide (a), MPEG2000 (b), the physical mixture of lactide and MPEG2000 (c) and the diblock copolymer MPEG-PDLLA (d).

Figure 2. ¹H NMR spectrum of mPEG-PDLLA (50:50).

Table 1. Molecular weight and molecular weight distribution of mPEG-PDLLA.

Polymer number	Mn by ^1H NMR	Mw/Mn by GPC	mPEG content%
110301	3810.1	1.186	52.49
110302	4315.5	1.236	46.30
110303	4280.0	1.244	46.73

Figure 3. Gel permeation chromatograms of mPEG-PDLLA.

Figure 4. Size distribution of arginine-dispersed DTX-PM measured by DLS (a) and Atom Force Microscopy (AFM) of the DTX-PM (b).

Table 2. Characteristics of dispersed DTX-PM in deionized water or arginine (2.0 mg/ml).

Solvent	Size (nm)	PDI	E.E%	D.L%
Deionized  water	26.3 ± 0.3	0.232 ± 0.003	92.30 ± 1.69	16.50 ± 2.94
Arginine  (2.0 mg/ml)	28.6 ± 0.5	0.224 ± 0.005	95.67 ± 1.45	15.96 ± 2.12

Figure 5. In vitro release profile of DTX from AR-DTX-PM and Glu-DTX-PM in PBS7.4 (0.5% of Tween80 and 5% bovine serum) at 37 °C (n = 3).

Figure 6. The change of diameter of arginine-dispersed DTX-PM and 5% glucose-dispersed DTX-PM diluted with 5% glucose.

Figure 7. HPLC chromatogram of alkaline degradation of DTX.

Table 3. PH value of dispersed DTX-PM in arginine of different concentrations and diluted with either 5% glucose or 0.9% NaCl*.

	pH value
Concentration of arginine solution (mg/ml)	Diluted with 5% glucose	Diluted with 0.9% NaCl
6.0	10.23	10.46
3.0	9.22	9.37
1.5	8.77	8.85

*The lyophilized DTX-PM powders were first dispersed in arginine solution to give DTX concentration of 10.0 mg/ml and then the solution was diluted 10 times with either 5%glucose or 0.9% NaCl.

Table 4. Single impurity content (S) and total impurity content (T) of 5% glucose dilution of DTX-PM dispersed in arginine (AR) with a series concentration of 1.5, 3.0, 6.0 mg/ml, respectively.*.

Time (h) AR (mg/ml)	0		1		2		4		6
	S	T	S	T	S	T	S	T	S	T
	1.50	0.48	0.98	0.57	1.07	0.59	1.06	0.60	1.09	0.62	1.15
3.00	0.62	1.25	0.81	1.78	1.84	2.09	2.17	2.56	2.38	2.80
6.00	2.33	2.94	3.78	4.63	4.86	5.86	7.21	8.55	9.50	11.20

*The lyophilized DTX-PM powders were first dispersed in arginine solution to give DTX concentration of 10.0 mg/ml and then the solution was diluted 10 times with 5%glucose.

Figure 8. Pyrene excitation spectra of mPEG-PDLLA aqueous solutions (emission wavelength at 390 nm).

Figure 9. Intensity ratio of I₃₃₇/I₃₃₄ versus logC for mPEG-PDLLA (50/50) in (a) water, (b) 2 mgċml^–1 arginine solution, (c) 4 mgċml^–1 arginine solution and (d) 8 mgċml^–1 arginine solution.

Table 5. CMC value of mPEG-PDLLA in arginine solution of different concentration (n = 5,).

C (mg ml^–1)	0.0	2.0	4.0	8.0
CMC (μg ml^–1)	3.31 ± 0.21	3.10 ± 0.16	3.47 ± 0.33	2.88 ± 0.25

Table 6. The stabilizing time of DTX-PM dispersed with different solutions.

Solution	5% glucose	Arginine (5 mg/ml)	Glycocyamine-NaOH	Glycocyamine-ammonia	Glycocyamine-ethylenediamine
Stabilizing time (h)	1	24	5	24	24

Figure 10. The electrostatic interaction and hydrogen bond formation between arginine and the taxanes.

Figure 11. Variation of body weight in beagle dogs time curves. The results are shown as the means ± SD (n = 4).

Figure 12. The variation of white blood cells (WBC, a), neutrophil % (Neut, b), platelets (PLT, c), red blood cells (RBC, d) and hemoglobin (HEG, e) during the observation (n = 4).

Figure 13. The plasma concentration time curves of DTX from DTX-PM and DTX injection. The results are shown as the means ± SD (n = 6).

Table 7. The pharmacokinetic parameters of DTX for DTX injection and DTX-PM.

	DTX injection	DTX-PM
t1/2 (h)	24.06 ± 14.22	20.44 ± 5.23
Tmax (h)	0.43 ± 0.14	0.43 ± 0.14
Cmax (ng/ml)	3465.00 ± 1448.94	1487.83 ± 465.73**
AUC(0–24h) (h*ng/ml)	2121.93 ± 599.11	1038.53 ± 264.87**
Vd (ml/kg)	23652.08 ± 14702.39	40069.44 ± 15009.67**
Cl (ml/h/kg)	679.46 ± 170.72	1345.89 ± 286.79**
MRT (h)	1.64 ± 0.24	1.20 ± 0.12

**p < 0.01 compared to DTX injection.

Figure 14. The antitumor efficacy against mice bearing S180. (a) The relative tumor volume-time curve; (b) the survival rate change; (b) the body weight change. The results are shown as means ± SD (n = 7).

Figure 15. In vivo infrared (NIR) optical imaging of DiR injection and AR-DTX-PM at different time point on S180 allograft tumor in SPF mice, and ex vivo images of dissected tissues after 8 h.