Morphological Analysis of Trafficking and Processing of Anionic and Cationic Liposomes in Cultured Cells

Yuji Tomori
Norio Iijima
Shuji Hinuma
Hirotaka Ishii
Ken Takumi
Shinro Takai
Hitoshi Ozawa

Liposomes
 artificial phospholipid vesicles
 have been developed as a non-viral drug delivery system to allow contained agents to be efficiently delivered to target sites via systemic circulation. Liposomes have been used as a gene transfer tool with cultured cells; however
 their precise trafficking and processing remain uncertain. Furthermore
 liposomes with different surface charges are known to exhibit distinct properties. The purpose of the current study was to elucidate the intracellular trafficking and processing of liposomes with anionic and cationic surface charges from a morphological view point. We found that cationic liposomes (CLs) were more effectively taken by the cells than anionic liposomes (ALs). Confocal laser scanning microscopy and transmission electron microscopy demonstrated distinct intracellular localization and processing patterns of ALs and CLs. ALs and their contents were localized in lysosomes but not in cytosol
 indicating that ALs are subjected to the endosome-lysosome system. In contrast
 contents of CLs were distributed mainly in the cytosol. CLs appear to disturb the cell membrane and then collapse to release their contents into the cytosol. It is feasible that the contents of CLs enter the cytosol directly rather than via the endosome-lysosome system.

ACTA HISTOCHEMICA ET CYTOCHEMICA

JAPAN SOC HISTOCHEMISTRY & CYTOCHEMISTRY

51

2

10.1267/ahc.17021

https://doi.org/10.1267/ahc.17021
https://www.ncbi.nlm.nih.gov/pubmed/29867281
https://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=JSTA_CEL&SrcApp=J_Gate_JST&DestLinkType=FullRecord&KeyUT=WOS:000431254600003&DestApp=WOS_CPL
http://orcid.org/0000-0003-2044-316X