Facile Preparation of Internally Self-assembled Lipid Particles Stabilized by Carbon Nanotubes

Yogita Patil-Sen; Amin Sadeghpour; Michael Rappolt; Chandrashekhar V. Kulkarni

doi:10.3791/53489

A subscription to JoVE is required to view this content. Sign in or start your free trial.

Method Article

Facile Preparation of Internally Self-assembled Lipid Particles Stabilized by Carbon Nanotubes

9.5K views

⸱

DOI:

10.3791/53489

⸱

February 19th, 2016

Yogita Patil-Sen¹ , Amin Sadeghpour² , Michael Rappolt² , Chandrashekhar V. Kulkarni¹

¹Centre for Materials Science, School of Physical Sciences and Computing, University of Central Lancashire, ²School of Food Science & Nutrition, University of Leeds

Summary

We report on a smart application of carbon nanotubes for kinetic stabilization of lipid particles that contain self-assembled nanostructures in their cores. The preparation of lipid particles requires rather low concentrations of carbon nanotubes permitting their use in biomedical applications such as drug delivery.

Abstract

We present a facile method to prepare nanostructured lipid particles stabilized by carbon nanotubes (CNTs). Single-walled (pristine) and multi-walled (functionalized) CNTs are used as stabilizers to produce Pickering type oil-in-water (O/W) emulsions. Lipids namely, Dimodan U and Phytantriol are used as emulsifiers, which in excess water self-assemble into the bicontinuous cubic Pn3m phase. This highly viscous phase is fragmented into smaller particles using a probe ultrasonicator in presence of conventional surfactant stabilizers or CNTs as done here. Initially, the CNTs (powder form) are dispersed in water followed by further ultrasonication with the molten lipid to form the final emulsion. During this process the CNTs get coated with lipid molecules, which in turn are presumed to surround the lipid droplets to form a particulate emulsion that is stable for months. The average size of CNT-stabilized nanostructured lipid particles is in the submicron range, which compares well with the particles stabilized using conventional surfactants. Small angle X-ray scattering data confirms the retention of the original Pn3m cubic phase in the CNT-stabilized lipid dispersions as compared to the pure lipid phase (bulk state). Blue shift and lowering of the intensities in characteristic G and G' bands of CNTs observed in Raman spectroscopy characterize the interaction between CNT surface and lipid molecules. These results suggest that the interactions between the CNTs and lipids are responsible for their mutual stabilization in aqueous solutions. As the concentrations of CNTs employed for stabilization are very low and lipid molecules are able to functionalize the CNTs, the toxicity of CNTs is expected to be insignificant while their biocompatibility is greatly enhanced. Hence the present approach finds a great potential in various biomedical applications, for instance, for developing hybrid nanocarrier systems for the delivery of multiple functional molecules as in combination therapy or polytherapy.

Introduction

Over the last few decades, nanotechnology has emerged as a powerful tool especially in the field of preclinical development of medicine to combat notorious diseases such as cancer¹. In this context, nanoscale structures with size <1,000 nm are extensively explored as delivery vehicle of various active biomolecules such as drugs, proteins, nucleic acids, genes and diagnostic imaging agents^1-4. These biomolecules are either encapsulated within the nanoparticles or conjugated onto the surface of nanoparticles and are released at the site of action by triggers such as pH or temperature^5,6. Although extremely small in size, the large su....