Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2023 Apr 25;15(5):1335.
doi: 10.3390/pharmaceutics15051335.

A γ-Glutamyl Transpeptidase (GGT)-Triggered Charge Reversal Drug-Delivery System for Cervical Cancer Treatment: In Vitro and In Vivo Investigation

Jingxin Fu  1 , Likang Lu  1 , Manzhen Li  1 , Yaoyao Guo  1   2 , Meihua Han  1 , Yifei Guo  1 , Xiangtao Wang  1
Affiliations

A γ-Glutamyl Transpeptidase (GGT)-Triggered Charge Reversal Drug-Delivery System for Cervical Cancer Treatment: In Vitro and In Vivo Investigation

Jingxin Fu et al. Pharmaceutics. .

Abstract

Neutral/negatively charged nanoparticles are beneficial to reduce plasma protein adsorption and prolong their blood circulation time, while positively charged nanoparticles easily transverse the blood vessel endothelium into a tumor and easily penetrate the depth of the tumor via transcytosis. Γ-Glutamyl transpeptidase (GGT) is overexpressed on the external surface of endothelial cells of tumor blood vessels and metabolically active tumor cells. Nanocarriers modified by molecules containing γ-glutamyl moieties (such as glutathione, G-SH) can maintain a neutral/negative charge in the blood, as well as can be easily hydrolyzed by the GGT enzymes to expose the cationic surface at the tumor site, thus achieving good tumor accumulation via charge reversal. In this study, DSPE-PEG2000-GSH (DPG) was synthesized and used as a stabilizer to generate paclitaxel (PTX) nanosuspensions for the treatment of Hela cervical cancer (GGT-positive). The obtained drug-delivery system (PTX-DPG nanoparticles) was 164.6 ± 3.1 nm in diameter with a zeta potential of -9.85 ± 1.03 mV and a high drug-loaded content of 41.45 ± 0.7%. PTX-DPG NPs maintained their negative surface charge in a low concentration of GGT enzyme (0.05 U/mL), whereas they showed a significant charge-reversal property in the high-concentration solution of GGT enzyme (10 U/mL). After intravenous administration, PTX-DPG NPs mainly accumulated more in the tumor than in the liver, achieved good tumor-targetability, and significantly improved anti-tumor efficacy (68.48% vs. 24.07%, tumor inhibition rate, p < 0.05 in contrast to free PTX). This kind of GGT-triggered charge-reversal nanoparticle is promising to be a novel anti-tumor agent for the effective treatment of such GGT-positive cancers as cervical cancer.

Keywords: cervical cancer; charge reversal; paclitaxel; γ-glutamyl transpeptidase.

PubMed Disclaimer

Conflict of interest statement

The authors declare no conflict of interest.

Figures

Figure 1
Figure 1
The schematic diagram for the charge reversal of PTX-DPG NPs at the tumor site and their infiltration from microvessels into the tumor.
Figure 2
Figure 2
The synthetic route of DPG (a) and the reduction of Ellman’s reagent (b).
Figure 3
Figure 3
The schematic diagram for the formation of PTX−DPG−NPs and their charge−reversal triggered by GGT enzyme.
Figure 4
Figure 4
(a) 1H NMR of DPG. (b) Standard curve of L−cysteine. (c) Critical micelle concentrations (CMC) of PTX−DPG NPs measured by fluorescence spectrophotometer using pyrene as a probe. (d) Particle size distribution of PTX−DPG NPs. (e) Particle size distribution of Co−6 and DiR−labelled PTX−DPG NPs. (f) Scanning Electron Microscopy image of PTX−DPG NPs. (g) Transmission Electron Microscopy image of PTX−DPG NPs (Scale: 100 nm).
Figure 5
Figure 5
(a) Charge-reversal property of PTX−DPG NPs in 10 U/mL γ−GGT solution. (b) Storage stability of PTX−DPG NPs at 4 °C for 25 days. (c) The change in particle size of PTX−DPG NPs in various physical medium. (d) The change in the size distribution of PTX−DPG NPs in various physical medium. (e) In vitro analysis of hemolytic properties. (From left to right, the positive group, the negative group, 1.8 mg/mL, 1 mg/mL, 0.5 mg/mL, 0.25 mg/mL, 0.1 mg/mL PTX−DPG NPs). (f) Drug release profile of PTX injection (at pH 7.4) and DPG−PTX NPs (at different pH values). (g) DSC pattern of PTX−DPG NPs. (h) XRD pattern of PTX−DPG NPs.
Figure 6
Figure 6
(a) MTT assay of PTX-DPG NPs and free PTX in the Hela cell line. (b) Cellular uptake of Co-6-labeled PTX-DPG NPs in the Hela cell line at a different time point (Blue-DAPI, Green- Co-6-labelled PTX-DPG NPs).
Figure 7
Figure 7
The in vivo biodistribution of DiR-labeled DPG micelles and PTX-DPG NPs in Hela tumor-bearing mice. Dynamic in vivo bio-distribution of Dir-labeled DPG micelles (a) and PTX-DPG NPs (b) at different time points (from left to right: 0.2 h, 0.5 h, 1 h, 2 h, 4 h, 6 h, 8 h, 12 h, and 24 h) post-dose through the tail vein. The fluorescent images of the tumor and major organs of mice receiving DiR-labelled DPG micelles (c) and PTX-DPG NPs (d) 24 h post-dose (from left to right: tumor, heart, liver, spleen, lung, kidney, and brain) (n = 3, mean ± SD) and their Fluorescence semi-quantitative analysis (e,f).
Figure 8
Figure 8
Schematic illustration of treatment of chemotherapy to Hela tumor−bearing mice (a). The mean tumor volume change (b) and the average tumor weight (c) of mice in each group. The results are presented as the mean ± SD, n = 6. ** p < 0.01 vs. PTX injection or normal saline, * p < 0.05 vs. PTX injection or normal saline. The photo of a representative mouse (d) and the average body weight change (e) for each group. (f) The photo of dissected tumors of all mice.
Figure 9
Figure 9
(a) Tumor cytokines of serum TNF-α level in the mice treated with saline, PTX injection (8 mg/kg), PTX-DPG NPs (8 mg/kg and 16 mg/kg of PTX) (Mean ± SD, n = 3). The results are presented as the mean ± SD, n = 6. * p < 0.01 vs. PTX-DPG NPs (16 mg/kg), # p < 0.05 vs. PTX-DPG NPs (8 mg/kg), && p < 0.01 vs. saline, & p < 0.05 vs. PTX-DPG NPs (8 mg/kg). (b) Tumor cytokines of IFN-γ in the serum of mice treated with saline, PTX injection (8 mg/kg), PTX-DPG NPs (8 mg/kg and 16 mg/kg of PTX) (Mean ± s.d., n = 3). (c) H&E and Ki67 staining of tumor tissues in each group (Scale: 200×).
See this image and copyright information in PMC

Similar articles

See all similar articles

References

    1. Siegel R.L., Miller K.D., Fuchs H.E., Jemal A. Cancer statistics, 2022. CA Cancer J. Clin. 2022;72:7–33. doi: 10.3322/caac.21708. - DOI - PubMed
    1. Sharifi-Rad J., Quispe C., Patra J.K., Singh Y.D., Panda M.K., Das G., Adetunji C.O., Michael O.S., Sytar O., Polito L., et al. Paclitaxel: Application in Modern Oncology and Nanomedicine-Based Cancer Therapy. Oxid. Med. Cell Longev. 2021;2021:3687700. doi: 10.1155/2021/3687700. - DOI - PMC - PubMed
    1. Weaver B.A. How Taxol/paclitaxel kills cancer cells. Mol. Biol. Cell. 2014;25:2677–2681. doi: 10.1091/mbc.e14-04-0916. - DOI - PMC - PubMed
    1. Sofias A.M., Dunne M., Storm G., Allen C. The battle of “nano” paclitaxel. Adv. Drug Deliv. Rev. 2017;122:20–30. doi: 10.1016/j.addr.2017.02.003. - DOI - PubMed
    1. Nehate C., Jain S., Saneja A., Khare V., Alam N., Dubey R.D., Gupta P.N. Paclitaxel formulations: Challenges and novel delivery options. Curr. Drug Deliv. 2014;11:666–686. doi: 10.2174/1567201811666140609154949. - DOI - PubMed

LinkOut - more resources