Pharmacokinetics and in vitro/in vivo antitumor efficacy of aptamer-targeted Ecoflex^® nanoparticles for docetaxel delivery in ovarian cancer

Figures & data

Figure 1 (A) Physicochemical characteristics of the HER-2-specific aptamer-targeted Ecoflex^® nanoparticles loaded with DTX in comparison to non-targeted Ecoflex nanoparticles loaded with DTX. (B) Particle size and zeta potential diagrams of non-targeted Ecoflex nanoparticles loaded with DTX. (C) Particle size and zeta potential diagrams of aptamer-targeted Ecoflex nanoparticles loaded with DTX.

Abbreviations: DTX, docetaxel; PDI, polydispersity index; Apt-DTX-NPs, aptamer-conjugated nanoparticles loaded with docetaxel; RE30, drug release efficiency in 30 hours.

Figure 2 Micrographs obtained after immunohistochemistry test on cell suspensions of (A) SKOV-3 cells (HER-2-positive) and (B) MDA-MB-468 cells (HER-2-negative) to compare the presence of HER-2 receptors; and (C) micrographs of SKOV-3 tumor tissue, indicating the presence of HER-2 receptors on cell membrane (considered as 3+ score), defined as strong complete membrane staining in more than 30% of tumor cells.

Figure 3 Viability percent after 24 hours incubation of (A) SKOV-3 cells treated with DTX-NPs, Apt-DTX-NPs, and free drug with different concentrations in the range of 100–1,000 ng/mL, and (B) MDA-MB-468 cells treated with DTX-NPs, Apt-DTX-NPs, and free drug with different concentrations in the range of 10–100 ng/mL, and compared to control samples including blank NPs (NPs which were not loaded with DTX) and DMSO (in the maximum concentration used in treatment groups).

Note: Significant differences are marked as *p<0.05.

Abbreviations: DTX, docetaxel; DTX-NPs, non-targeted nanoparticles loaded with docetaxel; Apt-DTX-NPs, aptamer-conjugated nanoparticles loaded with docetaxel; Blank NPs, nanoparticles not loaded with DTX; DMSO, dimethyl sulfoxide.

Figure 4 Flow-cytomertry diagrams indicating the intensity of fluorescence in SKOV-3 (A) and MDA-MB-468 (B) cells, following 2 hours incubation with 1) blank NPs (NPs which were not loaded with RhB), 2) free RhB, 3) RhB-NPs (non-targeted nanoparticles loaded with RhB), and 4) Apt-RhB-NPs (aptamer-conjugated nanoparticles loaded with RhB).

Note: M1 portion represents autofluorescence of the nontreated cells and M2 portion represents any additional intensity of fluorescence caused by uptake of probe.

Abbreviations: FL, fluorescence; RhB, Rhodamine B.

Table 1 Pharmacokinetic parameters of Taxotere^® and Apt-DTX-NPs (results are presented as mean ± SD; n=3)

Formulations	AUC0–∞ (µg⋅h/mL)	CL (L/kg/h)	MRT (hours)	Vd (L/kg)	T1/2β (hours)	T1/2α (hours)
Taxotere^®	4.51±0.39*	1.11±0.10*	3.95±0.07*	4.38±0.30	2.70±0.05*	0.63±0.03
Apt-DTX-NPs	6.97±0.84	0.72±0.09	6.19±0.17	4.44±0.41	4.30±0.12	0.67±0.03
DTX-NPs	6.34±1.02	0.78±0.12	5.91±0.42	4.66±1.08	4.10±0.29	0.64±0.03

Note:

* p<0.05.

Abbreviations: Apt-DTX-NPs, aptamer-conjugated nanoparticles loaded with docetaxel; AUC, area under the curve; CL, clearance; DTX-NPs, non-targeted nanoparticles loaded with docetaxel; MRT, mean residence time; V_d, volume of distribution; T_1/2β, elimination half-life; T_1/2α, biodistribution half-life.

Figure 5 Mean plasma concentration–time profile of docetaxel (DTX) in Balb/c mice following intravenous administration of Taxotere^®, DTX-NPs (non-targeted nanoparticles loaded with docetaxel), and Apt-DTX-NPs (aptamer-conjugated nanoparticles loaded with docetaxel). The results are indicated as mean ± SD (n=3).

Figure 6 Tumor inhibition effect of different treatments by (A) changes in tumor volume and (B) changes in body weight of mice after treatment with normal saline (control group), Taxotere^®, Apt-DTX-NPs (aptamer-conjugated nanoparticles loaded with docetaxel), and DTX-NPs (non-targeted nanoparticles loaded with docetaxel). The results are indicated as mean ± SD (n=3) and significant differences are marked as *p<0.05.