Impact of molecular weight on the mechanism of cellular uptake of polyethylene glycols (PEGs) with particular reference to P-glycoprotein

Tingting Wang; Yingjie Guo; Yang He; Tianming Ren; Lei Yin; John Paul Fawcett; Jingkai Gu; Huimin Sun

doi:10.1016/j.apsb.2020.02.001

Impact of molecular weight on the mechanism of cellular uptake of polyethylene glycols (PEGs) with particular reference to P-glycoprotein

Acta Pharm Sin B. 2020 Oct;10(10):2002-2009. doi: 10.1016/j.apsb.2020.02.001. Epub 2020 Feb 20.

Authors

Tingting Wang^{1

2}, Yingjie Guo², Yang He³, Tianming Ren², Lei Yin¹, John Paul Fawcett², Jingkai Gu^{4

2

5}, Huimin Sun⁶

Affiliations

¹ Clinical Laboratory, First Hospital, Jilin University, Changchun 130061, China.
² Research Center for Drug Metabolism, College of Life Science, Jilin University, Changchun 130012, China.
³ Department of Pharmaceutical Sciences and Experimental Therapeutics, College of Pharmacy, University of Iowa, Iowa City IA 52242, USA.
⁴ Research Institute of Translational Medicine, First Hospital, Jilin University, Changchun 130061, China.
⁵ Beijing Institute of Drug Metabolism, Beijing 102209, China.
⁶ National Institutes for Food and Drug Control, Beijing 100050, China.

Abstract

Polyethylene glycols (PEGs) in general use are polydisperse molecules with molecular weight (MW) distributed around an average value applied in their designation e.g., PEG 4000. Previous research has shown that PEGs can act as P-glycoprotein (P-gp) inhibitors with the potential to affect the absorption and efflux of concomitantly administered drugs. However, questions related to the mechanism of cellular uptake of PEGs and the exact role played by P-gp has not been addressed. In this study, we examined the mechanism of uptake of PEGs by MDCK-mock cells, in particular, the effect of MW and interaction with P-gp by MDCK-hMDR1 and A549 cells. The results show that: (a) the uptake of PEGs by MDCK-hMDR1 cells is enhanced by P-gp inhibitors; (b) PEGs stimulate P-gp ATPase activity but to a much lesser extent than verapamil; and (c) uptake of PEGs of low MW (<2000 Da) occurs by passive diffusion whereas uptake of PEGs of high MW (>5000 Da) occurs by a combination of passive diffusion and caveolae-mediated endocytosis. These findings suggest that PEGs can engage in P-gp-based drug interactions which we believe should be taken into account when using PEGs as excipients and in PEGylated drugs and drug delivery systems.

Keywords: ACN, acetonitrile; AUC, area under the plasma concentration-time curve; CE, collision energy; Cmax, maximum plasma concentration; CsA, cyclosporine A; DBD, drug-binding domain; DDS, drug delivery system; DMEM, Dulbecco's modified Eagle's medium; DMSO, dimethyl sulfoxide; DP, declustering potential; Endocytosis; FBS, fetal bovine serum; HBSS, Hanks' balanced salt solution; HEPES, 4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid; IS, internal standard; LC−HRMS/MS, liquid chromatography−high resolution tandem mass spectrometry; MW, molecular weight; NBD, nucleotide binding domain; P-gp; P-gp, P-glycoprotein; P-gp-substrate; PAC, paclitaxel; PEG, polyethylene glycol; PEGs; Passive diffusion; VER, verapamil.