出版社：American Society for Biochemistry and Molecular Biology
摘要：The polyene antibiotic amphotericin B (AMB) is an effectiveantifungal agent whose therapeutic potential is limited by pooraqueous solubility and toxicity toward host tissues. Additionof apolipoprotein A-I to a multilamellar phospholipid vesicledispersion containing 20% (w/w) AMB induces the formation ofreconstituted high density lipoprotein (rHDL), with solubilizationof the antibiotic. Density gradient ultracentrifugation resultedin flotation of the complexes to a density of 1.16 g/ml, andnegative stain electron microscopy revealed a population ofdisk-shaped particles. Native gradient polyacrylamide gel electrophoresisindicated a particle diameter of 8.5 nm. Absorbance spectroscopyprovided evidence for AMB integration into the lipid milieu.AMB-rHDLs were potent inhibitors of Saccharomyces cerevisiaegrowth, yielding 90% growth inhibition at <1 µg/mlyeast culture. In studies with pathogenic fungal species, similargrowth inhibition characteristics were observed. Compared withAMB-deoxycholate micelles, AMB-rHDL displayed greatly attenuatedred blood cell hemolytic activity and decreased toxicity towardcultured hepatoma cells. In in vivo studies in immunocompetentmice, AMB-rHDLs were nontoxic at 10 mg/kg, and they showed efficacyin a mouse model of candidiasis at concentrations as low as0.25 mg/kg. These results indicate that AMB-rHDLs constitutea novel formulation that effectively solubilizes the antibioticand elicits strong in vitro and in vivo antifungal activitywith no observed toxicity at therapeutic doses.Supplementary key words apolipoprotein • phospholipid • Saccharomyces cerevisiae • fungus • Candida albicans • red blood cell • drug delivery • density gradient ultracentrifugation • electron microscopy
Abbreviations: AMB, amphotericin B; apoA-I, apolipoprotein A-I; DMPC, dimyristoylphosphatidylcholine; DMPG, dimyristoylphosphatidylglycerol; IC90, concentration at which 90% growth inhibition occurs; RBC, red blood cell; rHDL, reconstituted high density lipoprotein; YEPD, yeast extract peptone glucose broth medium
8.5 nm. Absorbance spectroscopy provided evidence for AMB integration into the lipid milieu. AMB-rHDLs were potent inhibitors of Saccharomyces cerevisiae growth, yielding 90% growth inhibition at <1 µg/ml yeast culture. In studies with pathogenic fungal species, similar growth inhibition characteristics were observed. Compared with AMB-deoxycholate micelles, AMB-rHDL displayed greatly attenuated red blood cell hemolytic activity and decreased toxicity toward cultured hepatoma cells. In in vivo studies in immunocompetent mice, AMB-rHDLs were nontoxic at 10 mg/kg, and they showed efficacy in a mouse model of candidiasis at concentrations as low as 0.25 mg/kg. These results indicate that AMB-rHDLs constitute a novel formulation that effectively solubilizes the antibiotic and elicits strong in vitro and in vivo antifungal activity with no observed toxicity at therapeutic doses.
Supplementary key words apolipoprotein • phospholipid • Saccharomyces cerevisiae • fungus • Candida albicans • red blood cell • drug delivery • density gradient ultracentrifugation • electron microscopy
Abbreviations: AMB, amphotericin B; apoA-I, apolipoprotein A-I; DMPC, dimyristoylphosphatidylcholine; DMPG, dimyristoylphosphatidylglycerol; IC90, concentration at which 90% growth inhibition occurs; RBC, red blood cell; rHDL, reconstituted high density lipoprotein; YEPD, yeast extract peptone glucose broth medium
