Arginine, glycine, aspartic acid peptide-modified paclitaxel and curcumin co-loaded liposome for the treatment of lung cancer: in vitro/vivo evaluation

Figures & data

Figure 1 The microstructural schematic diagram of RGD-PTX-CUR LPs.

Abbreviations: DSPE-PEG, distearoyl-l-a-phosphatidylethanolamine; PTX, paclitaxel; CUR, curcumin; LPs, liposomes; RGD, arginine, glycine, aspartic acid peptide.

Table 1 Characterization of the prepared LPs

Formulation	Mean diameter (nm)	PDI	Zeta potential (mV)	PTX		CUR
				DL%	ER%	DL%	ER%
RGD-PTX/CUR LPs	120.6±10.83	0.139±0.026	−5.62±1.13	7.6±2.13	85.3±6.72	8.6±1.72	82.3±7.31
PTX/CUR LPs	117.2±8.43	0.142±0.035	−6.25±1.69	7.2±3.21	76.5±6.24	8.7±1.65	83.9±6.82

Abbreviations: PDI, poly disperse index; PTX, paclitaxel; CUR, curcumin; DL%, drug-loading coefficient; ER%, encapsulation ratio; RGD, arginine, glycine, aspartic acid peptide; LPs, liposomes.

Figure 2 Transmission electron microscope photograph of PTX and CUR co-loaded LPs.

Note: (A) Not RGD modified, (B) RGD modified (magnification ×97,000).

Abbreviations: PTX, paclitaxel; CUR, curcumin; LPs, liposomes; RGD, arginine, glycine, aspartic acid peptide.

Figure 3 The release profile of free PTX, free CUR, PTX-CUR LPs and RGD-PTX-CUR LPs from release medium (50%, v/v, of ethanol) at 37°C in a shaking water bath at 75 rpm (n=6).

Abbreviations: PTX, paclitaxel; CUR, curcumin; LPs, liposomes; RGD, arginine, glycine, aspartic acid peptide.

Table 2 Physical stability of RGD-modified PTX and CUR co-loaded LPs at 25°C, 60% RH (n=3)

Parameters	0 day	2 months	3 months
Physical appearance	Milk white	Milk white	Milk white
Particle size (nm)	120.6±10.83	121.6±9.15	123.5±7.33
Zeta potential (mV)	−5.62±1.13	−7.2±1.42	−7.6±1.73
DL% (PTX)	7.6±2.13	7.3±3.42	7.2±4.23
ER% (PTX)	85.3±6.72	83.5±8.34	81.7±8.92
DL% (CUR)	8.6±1.72	8.4±1.56	8.1±1.65
ER% (CUR)	82.3±7.31	81.1±6.52	80.9±5.32

Abbreviations: RGD, arginine, glycine, aspartic acid peptide; PTX, paclitaxel; CUR, curcumin; LPs, liposomes; RH, relative humidity; DL%, drug-loading coefficient; ER%, encapsulation ratio.

Table 3 Pharmacokinetic parameters of drug after iv administration of LPs and suspensions to rats (n=10)

Parameters	PTX			CUR
	Free drug	PTX/CUR LPs	RGD-PTX/CUR LPs	Free drug	PTX/CUR LPs	RGD-PTX/CUR LPs
t1/2 (h)	5.4±1.4	11.5±2.2	13.5±2.6*	3.6±1.4	6.1±1.1	8.2±2.1*
AUC0–t (ng⋅h/mL)	6,256.3±612.7	10,335.3±983.2	12,760.4±1,102.1*	3,286.5±356.2	5,321.9±526.3	6,654.9±625.4*
AUC0–∞ (ng⋅h/mL)	7,105.4±659.3	12,315.2±916.3	14,251.3±1,014.5*	3,956.2±412.2	6,123.4±598.4	7,536.7±714.3*
MRT (h)	6.1±1.7	15.3±2.6	17.3±3.1*	4.8±1.3	8.2±1.8	11.4±2.1*
CL (L/h)	13.8±2.9	6.9±1.8	4.9±1.3*	11.2±1.2	6.2±1.1	4.1±1.2*

Note:

* p<0.05: RGD-PTX/CUR LPs and Free drug (PTX or CUR).

Abbreviations: PTX, paclitaxel; CUR, curcumin; RGD, arginine, glycine, aspartic acid peptide; LPs, liposomes; t_1/2, half-life time; MRT, mean residence time; CL, clearance.

Figure 4 Plasma concentration-time profiles.

Note: (A) PTX and (B) CUR after iv administration of different formulations to rats (n=10).

Abbreviations: PTX, paclitaxel; CUR, curcumin; LPs, liposomes; RGD, arginine, glycine, aspartic acid peptide.

Figure 5 Confocal images of cellular uptake.

Notes: (A) Free PTX/CUR, (B) PTX/CUR LPs, and (C) RGD-PTX/CUR LPs by 549 cells. Incubation time was 2 h.

Abbreviations: PTX, paclitaxel; CUR, curcumin; LPs, liposomes; RGD, arginine, glycine, aspartic acid peptide.

Table 4 Effect of free PTX/CUR, PTX/CUR LPs and RGD-PTX/CUR LPs on A549 cells in nude mice (n=12)

Formulation	TV (mm^3)		Tumor weight (mg)	R	IR (%)
	d1	d16
Control group	132±26	725±215	748±215	5.49±1.36
Free PTX/CUR	134±28	269±124	297±165	2.01±1.12	63.4
PTX/CUR LPs	135±24	232±119	229±124	1.72±0.81	68.7
RGD-PTX/CUR LPs	137±31	89±26a,b,c	95±32a,b,c	0.65±0.29a,b,c	88.2

Notes:

a p<0.01 vs control group;

b p<0.05 vs free PTX/CUR group;

c p<0.05 vs PTX/CUR LPs.

Abbreviations: PTX, paclitaxel; CUR, curcumin; RGD, arginine, glycine, aspartic acid peptide; LPs, liposomes; TV, tumor volume; R, relative tumor volume; IR, inhibited rate.

Figure 6 In vitro cytotoxicity analysis of free PTX/CUR, PTX/CUR LPs and RGD-PTX/CUR LPs on A549 cell lines.

Notes: (A) 24 hours, or (B) 48 hours. Cell viability assay was performed by MTT assay. *p<0.05 RGD-PTX/CUR LPs vs PTX/CUR LPs.

Abbreviations: PTX, paclitaxel; CUR, curcumin; LPs, liposomes; RGD, arginine, glycine, aspartic acid peptide.

Figure 7 The tumor volume in nude mice transplanted with a human adenocarcinoma (A549) cell line on day 16.

Note: (A) Control group, (B) free PTX/CUR, (C) PTX/CUR LPs and (D) RGD-PTX/CUR LPs.

Abbreviations: PTX, paclitaxel; CUR, curcumin; LPs, liposomes; RGD, arginine, glycine, aspartic acid peptide.