Gold liposomes for brain-targeted drug delivery: Formulation and brain distribution kinetics

This work was aimed to formulate transferrin (Tf) receptor targeted gold based theranostic liposomes which contain both docetaxel (DCX) and glutathione reduced gold nanoparticles (AuGSH) for brain-targeted drug delivery and imaging. AuGSH was prepared by reducing chloroauric acid salt using glutathione. The co-loading of DCX and AuGSH into liposomes was achieved by the solvent injection technique, and Tf was post-conjugated on the surface of the liposomes using carboxylated Vit-E TPGS (TPGS-COOH) as a linker. The liposomes were characterized for various parameters such as size, shape, surface charge, and drug release. The Tf receptor targeted gold liposomes were evaluated for the cytotoxicity by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) based colorimetric assay and in-vitro qualitative cellular uptake studies using confocal microscopy. The in-vivo site specific delivery of DCX was analyzed by the brain distribution study of DCX in comparison with marketed formulation (Docel™). A sustained drug release of about 70% was observed from liposomes in the span of 72 h. The in-vivo results demonstrated that targeted gold liposomes were able to deliver DCX into the brain by 3.70, 2.74 and 4.08-folds higher than Docel™ after 30, 120 and 240 min of the treatment, respectively. Besides, the results of these studies have suggested the feasibility of Tf decorated AuGSH and DCX co-loaded liposomes as a promising platform for targeted nano-theranostics.