Sunday, August 24, 2008

Buckysomes: Fullerene-Based Nanocarriers for Hydrophobic Molecule Delivery

Ranga Partha, Linsey R. Mitchell, Jennifer L. Lyon, Pratixa P. Joshi, and Jodie L. Conyers*

Department of Internal Medicine, The University of Texas Health Science Center at Houston, 6431 Fannin Street, Houston, Texas 77030

*Address correspondence to Jodie.L.Conyers@uth.tmc.edu.

ABSTRACT

We report the preparation and preliminary in vitro studies of nanocarriers termed “buckysomes,” which are self-assembled, spherical nanostructures composed of the amphiphilic fullerene AF-1. By inducing AF-1 self-assembly at an elevated temperature of 70 °C, dense spherical buckysomes with diameters of 100−200 nm were formed, as observed by electron microscopy and dynamic light scattering. The amphiphilic nature of AF-1 results in the formation of many hydrophobic regions within the buckysomes, making them ideal for embedding hydrophobic molecules to be tested in a drug delivery scheme. After confirming the cellular internalization of buckysomes embedded with the hydrophobic fluorescent dye 1,1′-dioctadecyl-3,3,3′,3′-tetramethylindocarbocyanine perchlorate, we embedded paclitaxel, a highly hydrophobic anticancer drug. The in vitro therapeutic efficacy of the paclitaxel-embedded buckysomes toward suppression of MCF-7 breast cancer cell growth was compared to that of Abraxane, a commercially available, nanoparticle-albumin-bound formulation of paclitaxel. Notably, the paclitaxel-embedded buckysomes demonstrated a similar efficacy to that observed with Abraxane in cell viability studies; these results were confirmed microscopically. Moreover, negative control studies of MCF-7 viability using empty buckysomes demonstrated that the buckysomes were not cytotoxic. The results of our studies suggest that buckysomes prepared from self-assembly of AF-1 at 70 °C are promising nanomaterials for the delivery of hydrophobic molecules.

Source

Background:

Self assembly of amphiphilic C60 fullerene derivatives into nanoscale supramolecular structures

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