A novel microemulsion-based isotonic perfusate modulated by Ringer’s solution for improved microdialysis recovery of liposoluble substances

Abstract

BackgroundMicrodialysis is promising technique for dynamic microbiochemical sampling from tissues. However, the application of typical aqueous perfusates to liposoluble substances is limited. In this study, a novel microemulsion (ME)-based isotonic perfusate (RS-ME) was prepared to improve the recovery of liposoluble components using microdialysis probes.ResultsBased on pseudo-ternary phase diagrams and comparisons of the ME area, Kolliphor® EL and Transcutol® P were selected as the surfactant and co-surfactant, respectively, with a weight ratio (Km) of 2:1 and ethyl oleate as the oil phase. The ME was mixed with Ringer’s solution at a 1:6 ratio (v/v) to obtain the isotonic RS-ME. The droplet size distribution of the ME in RS-ME was 78.3 ± 9.2 nm, with a zeta potential of − 3.5 ± 0.3 mV. By microdialysis perfusion, RS-ME achieved higher recovery rates of the poorly water-soluble compounds evodiamine (EVO) and ruthenium (RUT), i.e., 58.36 ± 0.57% and 49.40 ± 0.57%, respectively, than those of 20% (v/v) PEG 400 Ringer's solution (RS-PEG) and 10% (v/v) ethanol Ringer’s solution (RS-EtOH). In vivo microdialysis experiments confirmed that RS-ME captured EVO and RUT molecules around the dialysis membrane more efficiently and exhibited less spreading than RS-PEG and RS-EtOH.ConclusionsOwing to the nanosized droplets formed by lipid components in the RS-ME and the limited dispersion out of the dialysis membrane, we obtained good biocompatibility and reliable dialysis results, without affecting the tissue microenvironment. As a novel perfusate, RS-ME provides an easy and reliable approach to the microdialysis sampling of fat-soluble components.

Surface Modification of Curcumin Microemulsions by Coupling of KLVFF Peptide: A Prototype for Targeted Bifunctional Microemulsions

“…The zeta potential values of all MEs were slightly negative (from −0.1 to −0.3 mV). It is generally known that the system is stable when the absolute value of zeta potential is greater than 30 mV, but zeta potential does not fully reflect the stability of the microemulsions [ 62 ]. For microemulsions systems containing nonionic surfactants, steric hindrance plays an important role in stability.…”

“…For microemulsions systems containing nonionic surfactants, steric hindrance plays an important role in stability. The stability of microemulsions with a low absolute value of the zeta potential were reported stable [ 62 ]. The colloidal stability of MEs with a slightly negative charge was previously discussed [ 15 ].…”

“…The colloidal stability of MEs with a slightly negative charge was previously discussed [ 15 ]. Several reports have shown that MEs containing slightly negative values of the zeta potential have shown a good colloidal stability [ 17 , 62 , 63 , 64 , 65 ]. However, only obtaining the zeta potential value is not enough to predict the stability of formulations, and a stability study should be performed to confirm the stability of the formulation in our future study.…”