Time to sonicate the nanoparticles

By February 14th, 2017

The RAMP centre’s Ben Muir and Shaun Howard were acknowledged in a paper published by a cohort of CSIRO and RMIT authors for our contribution to a high-throughput synthesis and screening of nanoparticle formations.

Self-assembled Lyotropic Liquid Crystalline Phase Behavior of Monoolein–Capric Acid–Phospholipid Nanoparticulate Systems

† School of Science, College of Science, Engineering and Health, RMIT University, Melbourne, Victoria 3000, Australia
‡ CSIRO Manufacturing, Clayton, Victoria 3168, Australia
Langmuir, 2017, 33 (10), pp 2571–2580
Publication Date (Web): February 13, 2017
Copyright © 2017 American Chemical Society
*(N.T.) School of Science, RMIT University, 124 La Trobe Street, Melbourne 3000, Victoria, Australia. Phone: +61 3 9925 2131. E-mail: nhiem.tran@rmit.edu.au., *(C.J.D.) School of Science, RMIT University, 124 La Trobe Street, Melbourne 3000, Victoria, Australia. Phone: +61 3 9925 4265. E-mail: calum.drummond@rmit.edu.au.

Abstract

abstract image

Some commonly observed lyotropic liquid crystalline phases of amphiphilic lipid self-assemblies. In order of increasing negative interfacial curvature, these are the fluid lamellar phase (Lα), the inverse bicontinuous cubic phases with crystallographic space group Im3m (QIIP) and Pn3m (QIID), the inverse hexagonal phase (HII), and the inverse micellar phase (L2).

We report here the lyotropic liquid crystalline phase behavior of two lipid nanoparticulate systems containing mixtures of monoolein, capric acid, and saturated diacyl phosphatidylcholines dispersed by the Pluronic F127 block copolymer. Synchrotron small-angle X-ray scattering (SAXS) was used to screen the phase behavior of a library of lipid nanoparticles in a high-throughput manner. It was found that adding capric acid and phosphatidylcholines had opposing effects on the spontaneous membrane curvature of the monoolein lipid layer and hence the internal mesophase of the final nanoparticles. By varying the relative concentration of the three lipid components, we were able to establish a library of nanoparticles with a wide range of mesophases including at least the inverse bicontinuous primitive and double diamond cubic phases, the inverse hexagonal phase, the fluid lamellar phase, and possibly other phases. Furthermore, the in vitrocytotoxicity assay showed that the endogenous phospholipid-containing nanoparticles were less toxic to cultured cell lines compared to monoolein-based counterparts, improving the potential of the nonlamellar lipid nanoparticles for biomedical applications.