Another class of drug delivery systems where nanotechnology offers interesting solutions
is in the area of nanomaterials that carry drugs to their destination sites and also have
functional properties. Certain nanostructures can be controlled to link with a drug, a
targeting molecule, and an imaging agent, then attract specific cells and release their
payload when required. Because of their nanoscale size, nanostructures have the ability
to enter the cells, as cells will typically internalize materials below 100nm. Some of the
leading nanostructures being used for this purpose include fullerenes, dendrimers, and
nanoshells.

Fullerenes (or Buckyballs) are natural hollow spheres, one nanometer in diameter, made
up of 60 carbon atoms. Fullerenes create a unique drug delivery platform that allows
active pharmacopheres to be grafted to its surface in three-dimensional orientations for
precise control in matching fullerene compounds to biological targets, in entrapping
atoms within the fullerene cage, and for attaching fullerene derivatives to targeting agents.
C Sixty is developing fullerene-based drug delivery platforms which link fullerenes with
antibodies and other targeting agents. Some of C Sixty`s drug delivery systems include
fullerene-decorated chemotherapeutic constructs, fullerene-radiopharmaceuticals, and
fullerene-based liposome systems, called Buckysomes, for the delivery of single drug
loads or multiple drug cocktails. Employing rational drug design, C Sixty has produced
several drug candidates using its fullerene platform technology in the areas of HIV/AIDS,
neuro-degenerative disorders and cancer.
Another nanomaterial used as a drug delivery scaffold is the dendrimer, a polymer
molecule discovered by Don Tomalia of Dendritic Nanotechnologies. Researchers such
as James Baker of the University of Michigan are using dendrimers to get genetic
material or tumor-destroying therapies into a cell without triggering an immune response.
This is due to the dendrimer`s small size and branched structure. Dendrimers can be
designed to release attached compounds in response to a specific molecule or chemical
reaction.

A layered sphere called a nanoshell is being developed by Nanospectra for drug delivery.
The nanoshell has a gold exterior layer which covers interior layers of silica and drugs.
Nanoshells can be made to absorb light energy and then convert it to heat. As a result,
when nanoshells are placed next to a target area such as tumor cell, it can release tumorspecific
antibodies when infrared light is administered.