Examining the Cellular Transport Pathway of Fusogenic Quantum Dots Conjugated With Tat Peptide

Jie Dai; Jun Wang; Xuan Yang; Zixing Xu; Gang Ruan

doi:10.3389/fbioe.2022.831379

Examining the Cellular Transport Pathway of Fusogenic Quantum Dots Conjugated With Tat Peptide

Front Bioeng Biotechnol. 2022 May 27:10:831379. doi: 10.3389/fbioe.2022.831379. eCollection 2022.

Authors

Jie Dai¹, Jun Wang¹, Xuan Yang^{2

3}, Zixing Xu¹, Gang Ruan^{1

2

3

4

5}

Affiliations

¹ Department of Biomedical Engineering, College of Engineering and Applied Sciences, Nanjing University, Nanjing, China.
² Wisdom Lake Academy of Pharmacy, Xi'an Jiaotong-Liverpool University, Suzhou, China.
³ Nanobiotechnology and Nanomedicine Center, Xi'an Jiaotong-Liverpool University, Suzhou, China.
⁴ Shenzhen Research Institute of Nanjing University, Nanjing, China.
⁵ Institute of Materials Engineering, College of Engineering and Applied Sciences, Nanjing University, Nanjing, China.

Abstract

Understanding the underlying transport mechanism of biological delivery is important for developing delivery technologies for pharmaceuticals, imaging agents, and nanomaterials. Recently reported by our group, SDots are a novel class of nanoparticle delivery systems with distinct biointerface features and excellent fusogenic capabilities (i.e., strong ability to interact with the hydrophobic portions of biomembranes). In this study, we investigate the cellular transport mechanism of SDots conjugated with Tat peptide (SDots-Tat) by live-cell spinning-disk confocal microscopy combined with molecular biology methods. Mechanistic studies were conducted on the following stages of cellular transport of SDots-Tat in HeLa cells: cellular entry, endosomal escape, nucleus entry, and intranuclear transport. A key finding is that, after escaping endosomes, SDots-Tat enter the cell nucleus via an importin β-independent pathway, bypassing the usual nucleus entry mechanism used by Tat. This finding implies a new approach to overcome the nucleus membrane barrier for designing biological delivery technologies.

Keywords: cell-penetrating peptide; delivery; nanoparticle; nucleus entry; quantum dot; targeting; vesicle escape.