Lysosome-targeted octadecyl-rhodamine B-liposomes enhance lysosomal accumulation of glucocerebrosidase in Gaucher's cells in vitro.

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.