Temperature effects on the aggregation state and activity of Amphotericin B

Polyene antibiotic amphotericin B in monomolecular layers: spectrophotometric and scanning force microscopic analysis

“…In particular the organization of AmB in the environment of lipid membranes has been recently addressed as directly relevant to the pharmacological usefulness of the drug [12–15]. There are several lines of support for the concept of formation of membrane channels by AmB, mainly based on the results of experiments with ion permeability across lipid membranes [4,16–18]. In this report we present for the first time a direct indication of the size of such a molecular pore formed by AmB based on pronounced spectral shifts of electronic absorption bands of substrate‐supported AmB monolayers and scanning force microscopy imaging of the surface topography of monomolecular layer composed of the drug and dipalmitoylphosphatidylcholine (DPPC).…”

Amphotericin B/Emulsion Admixture Interactions: An Approach Concerning the Reduction of Amphotericin B Toxicity

“…It has been reported that the AmB may present various patterns of activity against ergosterol‐containing fungal cells with respect to the toxicity against cholesterol‐containing mammalian cells, depending on its molecular presentation 22,24,26,31,32. Indeed, monomers were lessF efficient than aggregates of oligomers at inducing the permeability of a cholesterol‐containing membrane to potassium 33.…”

“…Typically, it is assumed that the spectral bands indicating the existence of monomers and aggregates species of AmB are located around 409 nm, and 327 nm, respectively 23. Previous studies showed that the selectivity against mammalian and fungal cells also depends on the aggregation state of AmB 22,24–26. Only self‐associated AmB was shown to increase K + permeability of cholesterol‐containing egg phosphatidyl choline vesicles, whereas both monomer and aggregate species modify K + permeability in ergosterol‐containing liposomes 26.…”

Amphotericin B Formulations and Drug Targeting

“…[33][34][35] Basically, the prevalence of the monomer form or different types of aggregates depend on the interaction AmB-solvent. For instance, water pH changes from 7.4 to 12 will transform the insoluble aggregates of AmB to the soluble monomer form of AmB.…”