Lysosome-Targeted Octadecyl-Rhodamine B-Liposomes Enhance Lysosomal Accumulation of Glucocerebrosidase in Gaucher‘S Cells In Vitro

Abstract

Aim: We hypothesized that liposomes modified with lysosomotropic octadecyl-rhodamine B (Rh) and loaded with therapeutic glucocerebroside velaglucerase alfa (VPRIV™) will improve lysosomal delivery of the enzyme into Gaucher‘s cells. Materials & methods: Confocal microscopy and flow cytometry were used to evaluate the ability of Rh-modified liposomes loaded with VPRIV to improve the lysosomal targeting in monocyte-derived macrophages and Gaucher‘s fibroblasts. Results: Confocal microscopy demonstrated that Rh-modified liposomes localized primarily in the lysosomes. As confirmed by flow cytometry using specific substrate 5-(pentafluorobenzoylamino)fluorescein diglucoside, intralysosomal accumulation of VPRIV in the cells treated with Rh-modified liposomes was significantly increased (up to 68%) relative to the cells treated with plain liposomes or free VPRIV. Conclusion: Rh-modified lysosomotropic liposomes can improve lysosomal accumulation of liposomal enzymes both in nonphagocytic Gaucher‘s fibroblasts and phagocytic monocyte-derived macrophages.

Original submitted 25 April 2012; Revised submitted 6 August 2012; Published online 2 December 2012

Keywords::

• enzyme replacement therapy
• glucocerebroside
• liposomes
• lysosomal targeting
• rhodamine B
• velaglucerase alfa
• VPRIV™

Financial & competing interests disclosure

This research was funded by the NIH grant RO1 CA128486 to VP Torchilin. The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed.

No writing assistance was utilized in the production of this manuscript.

Ethical conduct of research

The authors state that they have obtained appropriate institutional review board approval or have followed the principles outlined in the Declaration of Helsinki for all human or animal experimental investigations. In addition, for investigations involving human subjects, informed consent has been obtained from the participants involved.

Additional information

Funding

This research was funded by the NIH grant RO1 CA128486 to VP Torchilin. The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed.