Vol 8, Issue 1, 2015 ISSN - 0974-2441 CARBON NANOTUBE: A FLEXIBLE APPROACH FOR NANOMEDICINE AND DRUG DELIVERY SUNDARAMOORTHY REVATHI*, MADHULATHA VUYYURU, MAGHARLA DASARATHA DHANARAJU Department of Pharmaceutics, GIET School of Pharmacy, Rajahmundry - 533 296, Andhra Pradesh, India. Email: revathigsp@gmail.com Received: 22 August 2014, Revised and Accepted: 25 October 2014 ABSTRACT Nanostructures of carbon were first observed in 1952, which gained worldwide interest due to their various physicochemical properties. Carbon nanotubes (CNTs) have found wide applications in the delivery of therapeutic agents such as peptides, proteins, siRNA, nucleic acids, genes, vaccines and also in bone and neural tissue regeneration. Functionalized CNTs have found to be biocompatible. The eye-catching features of these structures are their electronic, mechanical, optical and chemical characteristics, which open a way to future applications and make them good candidates for a wide variety of applications, including drug transporters, new therapeutics, delivery systems and diagnostics. Their unique surface area, stiffness, strength, and resilience have led to much excitement in the field of pharmacy. They can pass through membranes, carrying therapeutic drugs, vaccines, and nucleic acids deep into the cell to targets that are previously unreachable. The applications of carbon nanotubes are in tissue engineering, drug carrier release system, wound healing, in cancer treatment and as biosensor. The successful realization of CNT-based biosensors requires proper control of their chemical and physical properties, as well as their functionalization and surface immobilization. Real applications are still under development. The modifications are done to improve efficiency of carbon nanotubes by formulating luminescent carbon nanotubes, ultrathin carbon nano-needles, magnetically guided nanotubes. Researchers have recently developed a new approach to boron neutron capture therapy in the treatment of cancer using substituted carborane-appended water-Soluble single-wall carbon nanotubes. This article provides an overview of current nanotube technology, with a special focus on synthesis and purification, properties, benefits, and applications. Keywords: Carbon nanotubes, Biosensors, Tissue engineering, Biocompatible. INTRODUCTION These are allotropes of carbon with cylindrical carbon molecules having novel properties thus making them potentially useful in many fields like electronics, nanotechnology, optics and other fields including architecture. They have a wide variety of applications and also used in the construction of body armor. They are efficient thermal conductors due to their extraordinary strengths and unique electrical properties. In order to promote the use of carbon nanotube (CNT) in research and in development, more reliable methods of production have been developed out of which chemical vapor deposition (CVD), arc discharge and laser ablation are the most common methods [1]. They can be divided into single wall CNTs (SWCNT) and multi wall CNTs (MWCNT). In the former process, a cylindrical nanostructure formed by rolling up a single graphite sheet into a tube whereas the latter comprises of multi layered grapheme cylinders that are concentrically nested like rings on a tree trunk. Both have high tensile strength, ultralight weight and high chemical and thermal stability. It is also proved that CNT can enhance the chemical reactivity of important biomolecules and promote electron transfer reaction of proteins. These CNTs have the ability to buckle and collapse reversibly due to high stiffness and resilience. The hexagonal network having high C-C bond stiffness produces an axial young’s modulus of approximately 1 TPa and a tensile strength of 150 GPa, which makes these particles one of the most stiffest materials known yet have the capacity to deform electrically under compression. STRUCTURE [2] Nanotubes are considered as the members of fullerene structural family including the spherical buckyballs. The name nanotube is derived from their size where the diameter of a nanotube is of a few nanometers of approximately 1/50,000 th the width of a human hair. There exist many exotic fullerene structures like cones, tubes, regular spheres and also more strange and complicated shapes. Some of the most important and best known structures are as in Figs.1-4: • Cylinder: It is one of the structures of which a SWCNT is composed. These cylinders are generated when a grapheme sheet of a particular size is wrapped in a particular direction. We can roll the sheet only in a discreet set of directions to form a closed cylinder. For this, two Review Article Fig. 1: Structure of a carbon nanotube Fig. 2: Single-walled carbon nanotube (CNT), double-walled CNT, and triple-walled CNT