Molecular interactions between Pluronic F127 and saponin in aqueous solution

Abstract

Nanotechnology is important for the development of new materials capable to improve the development of novel drug delivery systems. Such systems may result in more efficient therapeutic effects with reduced toxicity and extended time in the organism and increase in bioavailability, biocompatibility, and solubility of drugs. Here it was investigated the interaction between the triblock copolymer Pluronic F127 (F127) and a natural bioactive amphiphilic saponin (SAP), extracted from Glycyrrhiza glabra roots, aiming to form micelle-like F127-SAP complexes in a pH 7.4 HEPES buffered aqueous solution, with potential nanobiotechnological applications. Differential scanning calorimetry (DSC), dynamic light scattering (DLS), and dynamic electrophoretic light scattering (DESL) were the techniques used in this investigation, at varied SAP concentrations below and above CMC at fixed 500 μM F127. The SAP-F127 molecular interactions were verified by changes in the critical micellar temperature (CMT) of F127 obtained from the DSC thermograms, while DLS and DELS data showed, respectively, the formation larger structures of the complexes relative to the single Pluronic micelles and zeta potential (ζ) values ranging from ca − 6.5 to − 9 mV, on varying the SAP concentration. Combined, these results indicate the formation of micelle-like complexes, with structure dependent on the SAP concentration, as highly promising agents in nanobiotechnology applications.