ABSTRACT
Purpose
To elucidate the effect of sterols on the aggregation of amphotericin B (AmB) in PEG-phospholipid micelles and its consequences on the hemolytic activity of AmB.
Methods
AmB-incorporated PEG-phospholipid micelles co-loaded with ergosterol, cholesterol, or 7-dehydrocholesterol were prepared at 4:1:1 and 20:5:1 ratios of polymer-to-sterol-to-AmB. The aggregation state of AmB was elucidated by UV–vis spectroscopy. AmB/sterol co-loaded PEG-phospholipid micelles were incubated with red blood cells and the hemolytic activity of AmB assessed by measurement of free hemoglobin.
Results
AmB in PEG-phospholipid micelles stayed mostly in a deaggregated state in the absence of sterol or with cholesterol, but aggregated in the presence of ergosterol or 7-dehydrocholesterol. The fraction of aggregated AmB in PEG-phospholipid micelles was lower at the 20:5:1 ratio. In an aggregated state or in the absence of sterol, AmB caused rapid and complete hemolysis. In contrast, deaggregated AmB co-loaded with cholesterol caused slower and incomplete hemolysis, especially at a 20:5:1 ratio.
Conclusions
The aggregation state of AmB in PEG-phospholipid micelles was sterol dependant. AmB/cholesterol co-loaded PEG-phospholipid micelles caused low in vitro hemolysis due to deaggregation of AmB and micellar stability, presumably owing to cholesterol/phospholipid versus cholesterol/AmB interactions in the interior core region.
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REFERENCES
Martin GS, Mannino DM, Eaton S, Moss M. The epidemiology of sepsis in the United States from 1979 through 2000. New Engl J Med. 2003;348(16):1546–54.
Pfaller MA, Diekema DJ. Epidemiology of invasive candidiasis: a persistent public health problem. Clin Microbiol Rev. 2007;20(1):133–63.
Laniado-Laborinand R, Cabrales-Vargas MN. Amphotericin B: side effects and toxicity. Rev Iberoamericana Micol. 2009;26(4):223–7.
Vakil R, Kwon GS. PEG-phospholipid micelles for the delivery of amphotericin B. J Contr Release. 2005;101(1–3):386–9.
Diezi TA, Bae Y, Kwon GS. Enhanced stability of PEG-block-poly(N-hexyl stearate L-aspartamide) micelles in the presence of serum proteins. Mol Pharm. 2010;7(4):1355–60.
Vakil R, Kwon GS. Effect of cholesterol on the release of amphotericin B from PEG-Phospholilpid micelles. Mol Pharm. 2008;5(1):98–104.
Barwicz J, Tancrede P. The effect of aggregation state of amphotericin-B on its interactions with cholesterol- or ergosterol-containing phosphatidylcholine monolayers. Chem Phys Lipids. 1997;85(2):145–55.
Fournier I, Barwicz J, Tancrede P. The structuring effects of amphotericin B on pure and ergosterol- or cholesterol-containing dipalmitoylphosphatidylcholine bilayers: a differential scanning calorimetry study. Biochim Biophys Acta Biomembr. 1998;1373(1):76–86.
Charbonneau C, Fournier I, Dufresne S, Barwicz J, Tancrede P. The interactions of amphotericin B with various sterols in relation to its possible use in anticancer therapy. Biophys Chem. 2001;91(2):125–33.
Lukyanov AN, Hartner WC, Torchilin VP. Increased accumulation of PEG-PE micelles in the area of experimental myocardial infarction in rabbits. J Contr Release. 2004;94(1):187–93.
Ashok B, Arleth L, Hjelm RP, Rubinstein I, Onyuksel H. In vitro characterization of PEGylated phospholipid micelles for improved drug solubilization: Effects of PEG chain length and PC incorporation. J Pharm Sci. 2004;93(10):2476–87.
Shin HC, Alani AWG, Rao DA, Rockich NC, Kwon GS. Multi-drug loaded polymeric micelles for simultaneous delivery of poorly soluble anticancer drugs. J Control Release. 2009;140(3):294–300.
Yu BG, Okano T, Kataoka K, Sardari S, Kwon GS. In vitro dissociation of antifungal efficacy and toxicity for amphotericin B-loaded poly(ethylene oxide)-block-poly( beta-benzyl-L-aspartate) micelles. J Control Release. 1998;56(1–3):285–91.
Vakil R, Knilans K, Andes D, Kwon GS. Combination antifungal therapy involving amphotericin B, rapamycin and 5-fluorocytosine using PEG-phospholipid micelles. Pharm Res. 2008;25(9):2056–64.
Demel RA, Bruckdorfer KR, Van Deenen LLM. Effect of sterol structure on permeability of liposomes to glucose, glycerol and RB+. Biochim Biophys Acta. 1972;255(1):321–30.
Langlet J, Bergès J, Caillet J, Demaret JP. Theoretical study of the complexation of amphotericin B with sterols. Biochim Biophys Acta Biomembr. 1994;1191(1):79–93.
Gruszecki WI, Gagos M, Herec M. Dimers of polyene antibiotic amphotericin B detected by means of fluorescence spectroscopy: molecular organization in solution and in lipid membranes. J Photochem Photobiol B Biol. 2003;69(1):49–57.
Chapados C, Barwicz J, Gruda I. Separation of overlapping spectra from evolving systems using factor-analysis.2. Amphotericin B in aqueous propanol and in aqueous lauroyl sucrose. Biophys Chem. 1994;51(1):71–80.
Kawabata M, Onda M, Mita T. Effect of aggregation of amphotericin B on lysophosphatidylcholine micelles as related to its complex formation with cholesterol or ergosterol. J Biochem. 2001;129(5):725–32.
Aramwit P, Yu BG, Lavasanifar A, Samuel J, Kwon GS. The effect of serum albumin on the aggregation state and toxicity of amphotericin B. J Pharm Sci. 2000;89(12):1589–93.
ACKNOWLEDGMENTS & DISCLOSURES
We gratefully acknowledge financial support from the National Institutes of Health (R01 AI-43346) and from the School of Pharmacy at the University of Wisconsin.
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Diezi, T.A., Kwon, G. Amphotericin B/Sterol Co-loaded PEG-Phospholipid Micelles: Effects of Sterols on Aggregation State and Hemolytic Activity of Amphotericin B. Pharm Res 29, 1737–1744 (2012). https://doi.org/10.1007/s11095-011-0626-z
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DOI: https://doi.org/10.1007/s11095-011-0626-z