Characterization of the colloidal properties, in vitro antifungal activity, antileishmanial activity and toxicity in mice of a distigmasterylhemisuccinoyl-glycero-phosphocholine liposome-intercalated amphotericin B

Abstract

Abstract1,2-Distigmasterylhemisuccinoyl-sn-glycero-3-phosphocholine (DSHemsPC) is a new lipid in which two molecules of stigmasterol (an inexpensive plant sterol) are covalently linked via a succinic acid to glycerophosphocholine. Since amphotericin B (AmB) interacts with sterols, we postulated that DSHemsPC could be used in AmB liposome formulations. Thirty-two DSHemsPC-AmB formulations were prepared using various mole ratios of DSHemsPC, phosphatidylcholine and phosphatidylglycerol at different pH. Most formulations had physical properties similar to AmBisome™: a particle diameter of about 100 nm, a monomodal distribution and a negative zeta potential. The red blood cell potassium release (RBCPR) IC50s for formulations spanned a range, with some being comparable to or greater than the IC50 observed using AmBisome™. A number of formulations had superior in vitro antifungal activity compared to AmBisome™. against all of the tested pathogenic yeasts and molds. The IC50s of formulations against L. major promastigotes and amastigotes for certain formulations were comparable with AmBisome™ and Fungizone™. Most formulations had maximum tolerated intravenous doses (MTD) of less than 10 mg/kg. However the formulation consisting of DSHemsPC/DMPC/DMPG/ AmB mole ratio 1.25/5.0/1.5/1.0 (prepared at pH 5.5) had excellent colloidal properties, a high IC50 for RBCPR, antifungal and antileishmanial activity similar to AmBisome™ and an MTD of 60 mg/kg. The characteristics of this DSHemsPC/DMPC/DMPG/AmB formulation make it suitable for further investigation to treat AmB-responsive pathogens.

Biodistribution and In Vivo Antileishmanial Activity of 1,2-Distigmasterylhemisuccinoyl- sn -Glycero-3-Phosphocholine Liposome-Intercalated Amphotericin B

“…The particle diameter of the samples was measured in triplicate using a dynamic light-scattering instrument (Nano-ZS; Malvern, United Kingdom). The zeta potential of the liposomes was determined on the same machine using the zeta potential mode and was the average of 20 measurements (12).…”

“…The amount of AMB intercalated into liposomes was determined after dissolving the liposomal formulation (1/1,000) in methanol and measuring the absorbance at 406 nm (12). The standard curve was linear up to 6 g AMB per ml methanol.…”

“…In our previous work, we used 1,2-distigmasterylhemisuccinoyl-sn-glycero-3-phosphocholine (DSHemsPC) to prepare several AMB liposomal formulations (12). DSHemsPC, an amphiphilic cholesterol analogue, can form a bilayer membrane; however, unlike cholesterol, it is unable to rapidly transfer between membranes (Fig.…”

Self-assembled amphotericin B-loaded polyglutamic acid nanoparticles: preparation, characterization and in vitro potential against Candida albicans

“…However, in AmB-L, there is an hypsochromic (blue) shift of 7−9 nm at λ max . 78 This shift could be attributed to the close association between AmB and the lipid bilayer in AmB-L. 79 Interaction of AmB with the PGA polymer in an aqueous environment results in formation of AmB aggregates that become entrapped inside the selfassembled PGA nanoparticles during their formation.…”

Difficulties in antifungal therapy with amphotericin B and the continuous search for new formulations: A literature review

“…Among them are the development of new formulations such as liposome base encapsulation (AmBisome), the formation of lipid complexes (ABELCET®), colloidal dispersions (Amphocil®) and nanoparticles. These new formulations have demonstrated decreased toxicity and increased therapeutic efficacy; however, their high cost has limited their use (Filippin and Souza, 2006;Iman et al, 2011;Kleinberg, 2006;Hillery, 1997;.…”