Development and characterization of lectin-functionalized vesicular constructs bearing amphotericin B for bio-film targeting

The long-term goal of this work will be to develop a topical formulation for oropharyngeal candidosis. Liposomes were prepared by the vesicle extrusion technique from mixtures of dipalmitoylphosphatidylcholine, cholesterol, and stearylamine incorporating a reactive phospholipid, the m-maleimidobenzoyl-N-hydroxysuccinimide ester derivative of dipalmitoyl-phosphatidylethanolamine, which was conjugated with the N-succinimidyl-S-acetylthioacetate derivatives of succinyl concanavalin A. Morphology of liposomes was studied by transmission electron microscopy and bio-film architecture using fluorescence microscopy. Lectinized vesicles were put into contact with bovine submaxillary mucin, to determine the in vitro activity and specificity. Targeting study was performed using 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay. The liposomes were found to have a diameter in the range of 360-450 and 390-510 run for uncoated and coated formulations, respectively. The MTT assay showed a strong association of lectin-bearing liposomes with candidal bio-film. The results suggest that surface-modified liposomes can effectively target candidal bio-film in vitro.