The use of fluorescence microscopy to define polymer localisation to the late endocytic compartments in cells that are targets for drug delivery

Richardson, Simon C. W. and Wallom, Kerri-Lee and Ferguson, Elaine L and Deacon, Samuel P. E. and Davies, Matthew W and Powell, Alison J and Piper, Robert C and Duncan, Ruth (2008) The use of fluorescence microscopy to define polymer localisation to the late endocytic compartments in cells that are targets for drug delivery. Journal of Controlled Release, 127 (1). pp. 1-11. ISSN 0168-3659. (doi:https://doi.org/10.1016/j.jconrel.2007.12.015) (The full text of this publication is not currently available from this repository. You may be able to access a copy if URLs are provided)

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Official URL
http://dx.doi.org/10.1016/j.jconrel.2007.12.015

Abstract

Macromolecular therapeutics and nano-sized drug delivery systems often require localisation to specific intracellular compartments. In particular, efficient endosomal escape, retrograde trafficking, or late endocytic/lysosomal activation are often prerequisites for pharmacological activity. The aim of this study was to define a fluorescence microscopy technique able to confirm the localisation of water-soluble polymeric carriers to late endocytic intracellular compartments. Three polymeric carriers of different molecular weight and character were studied: dextrin (Mw ~ 50,000 g/mol), a N-(2-hydroxypropyl)methacrylamide (HPMA) copolymer (Mw ~ 35,000 g/mol) and polyethylene glycol (PEG) (Mw 5000 g/mol). They were labelled with Oregon Green (OG) (0.3–3 wt.%; < 3% free OG in respect of total). A panel of relevant target cells were used: THP-1, ARPE-19, and MCF-7 cells, and primary bovine chondrocytes (currently being used to evaluate novel polymer therapeutics) as well as NRK and Vero cells as reference controls. Specific intracellular compartments were marked using either endocytosed physiological standards, Marine Blue (MB) or Texas-red (TxR)-Wheat germ agglutinin (WGA), TxR-Bovine Serum Albumin (BSA), TxR-dextran, ricin holotoxin, C6-7-nitro-2,1,3-benzoxadiazol-4-yl (NBD)-labelled ceramide and TxR-shiga toxin B chain, or post-fixation immuno-staining for early endosomal antigen 1 (EEA1), lysosomal-associated membrane proteins (LAMP-1, Lgp-120 or CD63) or the Golgi marker GM130. Co-localisation with polymer–OG conjugates confirmed transfer to discreet, late endocytic (including lysosomal) compartments in all cells types. The technique described here is a particularly powerful tool as it circumvents fixation artefacts ensuring the retention of water-soluble polymers within the vesicles they occupy.

Item Type: Article
Additional information: number of additional authors: 7;
Uncontrolled keywords: Endocytosis; Polymer conjugates; Nanomedicine; Intracellular trafficking
Subjects: Q Science
R Medicine
Divisions: Faculties > Sciences > Medway School of Pharmacy
Depositing User: Stewart Brownrigg
Date Deposited: 07 Mar 2014 00:05 UTC
Last Modified: 11 Jul 2014 15:09 UTC
Resource URI: https://kar.kent.ac.uk/id/eprint/40425 (The current URI for this page, for reference purposes)
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