Elemental Carbon and Nanotechnology
An element that can exist in two or more forms is said to be allotropic, the
different forms are called allotropes Carbon shows this properties and Diamond,
Graphite and Carbon 60 are the more stable allotropes of carbon.
The 1996 Nobel Prize for Chemistry has been won by Harold W. Kroto, Robert F.
Curl and Richard E. Smalley for their discovery in 1985 of a new allotrope of
carbon, in which the atoms are arranged in closed shells. The new form was
found to have the structure of a truncated icosahedron, and was named
Buckminsterfullerene, after the architect Buckminster Fuller who designed
geodesic domes in the 1960's.
In 1990 physicists W. Krätschmer and D.R. Huffman for the first time produced
isolable quantities of C60 by causing an arc between two graphite rods to burn in
a helium atmosphere and extracting the carbon condensate so formed using an
organic solvent.
C60 are spherical molecules about 1nm in diameter, comprising 60 carbon atoms
arranged as 20 hexagons and 12 pentagons: the configuration of a football. Hence
they find application as NanoPharmaceuticals with large drug payload in their cage
like structure. On the other hand with development of various chemical substitutes
for C60, it is possible to develop functionalized C60 with better drug targeting
properties.
C Sixty a company based in Texas, C Sixty has developed proprietary technology
for scalable production of artificial membranes based on derivatized fullerenes.
The company anticipates that these artificial membranes, also known as
Buckysomes, will prove useful in targeted delivery for a variety of different drugs
to specific sites of disease in the body. C Sixty has recently announced a
partnership with the University of Texas Health Science Center in Houston to
optimize these drug delivery systems to deliver a new generation of anesthetics to
critical sites with greatly increased efficacy and safety. Application of C60 for
drug delivery is taking off and we forecast wide variety of application of theses
interesting materials in the field of health sciences.
- C 60
Companies
Companies
BuckyUSA
Strem Chemicals Inc.
Hyperion Catalysis Int
SES Research
Nano-C
Suppliers
Biomaterials Inc
A carbon nanotube is a large molecule made of carbon atoms. The atoms are
arranged in hexagons, much like chicken wire, the same arrangement as in
graphite but rolled into a cylinder. Carbon nanotubes were discovered in 1991 by
S. Iijima. These intriguing structures have sparked much excitement in the recent
years. Currently, the physical properties are still being discovered and disputed.
What makes it so difficult is that nanotubes have a very broad range of
electronic, thermal, and structural properties that change depending on the
different kinds of nanotube (defined by its diameter, length, and chirality, or
twist).
Carbon nanotubes are adept at entering the nuclei of cells and may one day be
used to deliver drugs and vaccines. The modified nanotubes have so far only
been used to ferry a small peptide into the nuclei of fibroblast cells. But the
researchers are hopeful that the technique may one day form the basis for new
anti-cancer treatments, gene therapies and vaccines.
Hydroxyapatite and Nanotechnology
Hydroxyapatite (HAP) is a form of calcium phosphate with chemical formula
Ca10(PO4)6(OH)2. Hydroxyapatite is chemically similar to the mineral
component of bones and hard tissues in mammals. It is one of few materials that
are classed as bioactive, meaning that it will support bone ingrowth and
osseointegration when used in orthopaedic, dental and maxillofacial applications.
Incorporation of active agents or drugs by physical absorption within porous
HA-based implants has been frequently reported for orthopedic uses. Very
recently, there has been growing interest in nanocrystals of HAP as carriers for
bioactive agents. HAP has shown as a potential carrier for gene. New Delhi
(INDIA) based National Research Development Corporation (NRDC) has signed
a license agreement with American BioScience to develop a calcium phosphate
nanotechnology for non-viral gene delivery (USPT 6,555,376).
Related Publications
Study on drug release behaviour of CDHA/chitosan nanocomposites-Effect of
CDHA nanoparticles.NEW
Journal of Controlled Release, 2006, In Press
Cellular localisation of a water-soluble fullerene derivative
Experimental Neurology, 2005, 196, 381-389.
Carbon nanotubes for the delivery of therapeutic molecules.
Expert Opin Drug Deliv. 2004,1,57-65.
Preparation of nano-HAP as vectors for targeting delivery system
Key Engineering Materials, 2004, 254, 887-890 2004.
Patent Watch
Device and method for photoactivated drug therapy
Neuberger , USPT 6,397,102 May 28, 2002,
Nanocrystalline apatites and composites, prostheses incorporating them, and
method for their production
Ying , et al. USPT 6,013,591 January 11, 2000
Process of entrapping genetic materials in ultra-low size nanoparticles of
inorganic compounds to form non-viral carriers
Maitra, et al. USPT 6,555,376 April 29, 2003
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