Antitumor activity of docetaxel-loaded polymeric nanoparticles fabricated by Shirasu porous glass membrane-emulsification technique

Figures & data

Figure 1 Chemical structure of docetaxel (DTX) and 1,1′-dioctadecyl-3,3,3′,3′-tetramethylindotricarbocyanine iodide (DIR).

Figure 2 Synthetic route of poly(lactide)-D-α-tocopheryl polyethylene glycol 1000 succinate (PLA-TPGS).

Figure 3 (A and B) Schematic diagram of Shirasu porous glass (SPG) membrane emulsification. (A) SPG membrane-emulsification apparatus; (B) membrane-emulsification principle.

Figure 4 Hydrogen-1 nuclear magnetic resonance spectrum of poly(lactide)-D-α-tocopheryl polyethylene glycol 1,000 succinate.

Abbreviation: ppm, parts per million.

Table 1 Effects of surfactant type and surfactant concentration in aqueous phase in fabricating DTX-loaded PLA-TPGS nanoparticles on size, PDI, EE, and DLE

Surfactant	Concentration (wt%)	Mean diameter (nm)	PDI	EE (%)	DLE (%)
PVA	0.1	387.8 ± 6.7	0.210 ± 0.340	80.3 ± 8.9	17.1 ± 2.1
	0.5	306.8 ± 5.5	0.098 ± 0.064	81.8 ± 4.5	48.4 ± 3.3
	1	250.6 ± 15.7	0.078 ± 0.018	63.8 ± 7.1	32.7 ± 2.8
	2	237.6 ± 13.5	0.104 ± 0.023	49.7 ± 8.2	29.3 ± 3.1
F68	0.5	435.8 ± 15.0	0.162 ± 0.061	30.9 ± 3.3	2.2 ± 1.0
	1	397.0 ± 5.0	0.195 ± 0.020	21.8 ± 1.6	5.6 ± 4.8
	2	346.8 ± 4.9	0.235 ± 0.072	11.9 ± 4.9	3.9 ± 2.3
TPGS	0.5	306.8 ± 6.3	0.125 ± 0.076	33.2 ± 5.7	3.2 ± 1.8
	1	275.1 ± 4.5	0.005 ± 0.002	27.4 ± 1.7	7.2 ± 1.5
	2	256.1 ± 8.7	0.004 ± 0.003	16.9 ± 2.2	4.9 ± 1.3

Notes: The volumetric ratio of organic phase to aqueous phase was 1:15 (v/v), the membrane-pore size was 1.0 μm, and the transmembrane pressure was 1.0 MPa in three cycles.

Abbreviations: PLA-TPGS, poly(lactide)-D-α-tocopheryl polyethylene glycol 1000 succinate; DTX, docetaxel; PVA, polyvinyl alcohol; PDI, polydispersity index; EE, encapsulation efficiency; DLE, drug-loading efficiency; F68, pluronic; TPGS, d-α-tocopheryl polyethylene glycol 1000 succinate.

Table 2 Effects of volumetric ratio of organic to aqueous phase in fabricating DTX-loaded PLA-TPGS nanoparticles on size, PDI, EE, and DLE

Ratio	Mean diameter (nm)	PDI	EE (%)	DLE (%)
1:10	259.5 ± 3.1	0.121 ± 0.018	53.0 ± 3.7	29.9 ± 4.8
1:15	306.8 ± 5.5	0.098 ± 0.064	81.8 ± 4.5	48.4 ± 3.3
1:20	335.8 ± 3.7	0.029 ± 0.009	80.7 ± 5.4	27.2 ± 3.5

Notes: The concentration of PVA was 0.5%, the membrane-pore size was 1.0 μm, and the pressure was 1.0 MPa in three cycles.

Abbreviations: PLA-TPGS, poly(lactide)-D-α-tocopheryl polyethylene glycol 1000 succinate; DTX, docetaxel; PVA, polyvinyl alcohol; PDI, polydispersity index; EE, encapsulation efficiency; DLE, drug-loading efficiency.

Table 3 Effects of the transmembrane cycles in fabricating DTX-loaded PLA-TPGS nanoparticles on size, PDI, EE, and DLE

Cycles	Mean diameter (nm)	PDI	EE (%)	DLE (%)
1	461.9 ± 10.6	0.223 ± 0.029	18.9 ± 3.0	13.0 ± 3.1
2	384.8 ± 9.8	0.134 ± 0.012	47.1 ± 5.7	28.6 ± 2.6
3	306.8 ± 5.5	0.098 ± 0.064	81.8 ± 4.5	48.4 ± 3.3
4	247.7 ± 4.7	0.005 ± 0.003	70.6 ± 9.1	31.9 ± 3.0
5	236.1 ± 2.0	0.005 ± 0.002	71.8 ± 7.7	20.7 ± 6.1

Notes: The concentration of polymer in the organic phase was 15 mg/mL with 5% drug loading, the concentration of PVA was 0.5%, the membrane-pore size was 1.0 μm, and the transmembrane pressure was 1.0 MPa in three cycles.

Abbreviations: PLA-TPGS, poly(lactide)-D-α-tocopheryl polyethylene glycol 1000 succinate; DTX, docetaxel; PVA, polyvinyl alcohol; PDI, polydispersity index; EE, encapsulation efficiency; DLE, drug-loading efficiency.

Table 4 Effects of the transmembrane pressure in fabricating DTX-loaded PLA-TPGS nanoparticles on size, PDI, EE, and DLE

Pressure (MPa)	Mean diameter (nm)	PDI	EE (%)	DLE (%)
0.6	339.1 ± 5.1	0.137 ± 0.051	62.0 ± 6.8	40.4 ± 2.9
1.0	306.8 ± 5.5	0.098 ± 0.064	81.8 ± 4.5	48.4 ± 3.3
1.2	257.8 ± 3.6	0.012 ± 0.031	71.9 ± 8.5	28.8 ± 3.3

Notes: The concentration of polymer in the organic phase was 15 mg/mL and volumetric ratio of organic to aqueous phase was 1:15 with 5% drug loading, the concentration of PVA was 0.5%, and the membrane-pore size was 1.0 μm in three cycles.

Abbreviations: PLA-TPGS, poly(lactide)-D-α-tocopheryl polyethylene glycol 1000 succinate; DTX, docetaxel; PVA, polyvinyl alcohol; PDI, polydispersity index; EE, encapsulation efficiency; DLE, drug-loading efficiency.

Table 5 Effects of membrane-pore size in fabricating DTX-loaded PLA-TPGS nanoparticles on size, PDI, EE, and DLE

Pore size (μm)	Mean diameter (nm)	PDI	EE (%)	DLE (%)
0.5	ND	ND	ND	ND
0.8	272.8 ± 4.8	0.009 ± 0.003	60.4 ± 6.3	36.7 ± 2.0
1.0	306.8 ± 5.5	0.098 ± 0.064	81.8 ± 4.5	48.4 ± 3.3
1.5	437.1 ± 18.5	0.237 ± 0.102	77.9 ± 6.7	30.3 ± 1.9

Notes: The concentration of polymer in the organic phase was 15 mg/mL with 5% drug loading, the volumetric ratio of organic to aqueous phase was 1:15, the concentration of PVA was 0.5%, and the transmembrane pressure was 1.0 MPa in three cycles.

Abbreviations: ND, not determined (the small pore size of the membrane caused long duration to produce nanoparticles); PLA-TPGS, poly(lactide)-D-α-tocopheryl polyethylene glycol 1000 succinate; DTX, docetaxel; PVA, polyvinyl alcohol; PDI, polydispersity index; EE, encapsulation efficiency; DLE, drug-loading efficiency.

Table 6 Effects of PLGA and PLA-TPGS copolymer in fabricating DTX-loaded nanoparticles on size, PDI, EE, and DLE

Polymer	Mean diameter (nm)	PDI	EE (%)	DLE (%)	Zeta potential (mv)
PLGA	334.1 ± 2.7	0.013 ± 0.005	64.5 ± 2.7	38.8 ± 5.6	−16.4 ± 1.0
PLA-TPGS	306.8 ± 5.5	0.098 ± 0.064	81.8 ± 4.5	48.4 ± 3.3	−22.8 ± 0.7

Notes: The concentration of polymer in the organic phase was 15 mg/mL with 5% drug loading, the volumetric ratio of organic to aqueous phase was 1:15, the concentration of PVA was 0.5%, the membrane-pore size was 1.0 μm, and the transmembrane pressure was 1.0 MPa in three cycles.

Abbreviations: PLA-TPGS, poly(lactide)-D-α-tocopheryl polyethylene glycol 1000 succinate; PLGA, poly(lactic-co-glycolic acid); DTX, docetaxel; PVA, polyvinyl alcohol; PDI, polydispersity index; EE, encapsulation efficiency; DLE, drug-loading efficiency.

Table 7 Properties of PLA-TPGS nanoparticles on a pilot scale

Batch	Mean diameter (nm)	PDI	EE (%)	DLE (%)
1	295.7 ± 6.1	0.047 ± 0.005	83.2 ± 4.3	44.5 ± 2.4
2	301.9 ± 5.8	0.056 ± 0.018	85.7 ± 3.8	46.1 ± 3.1
3	306.8 ± 5.5	0.098 ± 0.064	81.8 ± 4.5	48.4 ± 3.3

Abbreviations: PLA-TPGS, poly(lactide)-D-α-tocopheryl polyethylene glycol 1000 succinate; PDI, polydispersity index; EE, encapsulation efficiency; DLE, drug-loading efficiency.

Figure 5 Scanning electron microscopy image of poly(lactide)-D-α-tocopheryl polyethylene glycol 1,000 succinate nanoparticles.

Figure 6 Cumulative release profiles of docetaxel-loaded poly(lactide)-D-α-tocopheryl polyethylene glycol 1,000 succinate (PLA-TPGS) nanoparticles (NPs) in phosphate-buffered saline (pH = 7.4) at 37°C.

Abbreviation: PLGA, poly(lactic-co-glycolic acid).

Table 8 Pharmacokinetic parameters in rats after iv injecting of Taxotere and DTX-loaded nanoparticles at a dose of 10 mg DTX/kg (n = 4)

Parameters	Unit	Taxotere®	PLA-TPGS NP	PLGA NP
AUC0–t	mg/L*h	23.4 ± 4.2	49.9 ± 16.11	28.0 ± 4.3
AUC0–∞	mg/L*h	23.5 ± 4.2	57.9 ± 14.0	35.1 ± 14.8
MRT0–t	h	1.6 ± 0.4	13.6 ± 2.12	4.1 ± 1.73
MRT0–∞	h	1.7 ± 0.5	29.4 ± 20.4	8.0 ± 7.8
t½	h	2.1 ± 1.2	27.9 ± 14.91	4.4 ± 3.64
CL	L/h/kg	0.4 ± 0.1	0.2 ± 0.12	0.3 ± 0.1
V	L/kg	1.4 ± 1.0	7.8 ± 5.3	1.6 ± 0.8
Tmax	h	0.5	0.5	0.5
Cmax	mg/L	15.9 ± 4.9	11.0 ± 2.4	10.2 ± 1.6

Notes:

1 P < 0.05 vs Taxotere

2 P < 0.01 vs Taxotere

3 P < 0.01 vs PLA-TPGS nanoparticles

4 P < 0.05 vs PLA-TPGS nanoparticles.

Abbreviations: AUC_0–t, area under the plasma concentration time curve from time 0 to t; MRT_0–t, mean residence time from time 0 to t; t_½, the elimination half-life; CL, total body clearance; V, volume of distribution; C_max and T_max are the maximum docetaxel concentration and the corresponding. time, respectively; DTX, docetaxel; PLA-TPGS, poly(lactide)-D-α-tocopheryl polyethylene glycol 1000 succinate; PLGA, poly(lactic-co-glycolic acid); NP, nanoparticle.

Figure 7 Pharmacokinetic behavior after intravenous injection at a dose of docetaxel (DTX) 10 mg/kg to Sprague Dawley rats of Taxotere and DTX-loaded poly(lactic-co-glycolic acid) (PLGA) and poly(lactide)-D-α-tocopheryl polyethylene glycol 1000 succinate (PLA-TPGS) nanoparticles (n = 4).

Abbreviation: NPs, nanoparticles.

Figure 8 (A and B) Biodistribution of docetaxel-loaded nanoparticles. (A) In vivo images of H22 tumor-bearing mice after intravenous injection (dashed circles indicate tumors). (B) Ex vivo images of tumors and organs of H22-bearing mice killed at 30 hours.

Abbreviations: PLA-TPGS, poly(lactide)-D-α-tocopheryl polyethylene glycol 1000 succinate; PLGA, poly(lactic-co-glycolic acid); NPs, nanoparticles; h, hour.

Figure 9 (A–C) In vivo antitumor efficiency of Taxotere and docetaxel-loaded poly(lactic-co-glycolic acid) (PLGA) and poly(lactide)-D-α-tocopheryl polyethylene glycol 1000 succinate (PLA-TPGS) nanoparticles (n = 7). (A) Weight changes of tumor-bearing mice; (B) survival rate of H22-bearing mice; (C) relative tumor-growth ratio (*P < 0.05, **P < 0.01).

Abbreviation: NPs, nanoparticles.