Single Walled and Multi Walled in Drug Delivery

Single Walled and Multi Walled in Drug Delivery

Introduction

The carbon nanotubes (CNT), discovered in 1991 and developed from that year, are materials that consist of only carbon, where the basic unit is a graphitic plane rolled to form a cylinder, forming a tube whose diameter is the order of several nanometers . The tendency is to consider the nanofibers as intermediate materials between micrometer fibers (produced by spinning) and nanotubes (Ose, 483). Many promising areas in nanotechnology is associated with carbon nanotubes. A carbon nanotube IS a frame structure or a giant molecule consisting of only carbon atoms. Carbon nanotube is easy to imagine, if you imagine that you minimize the tube is one of the molecular layers of graphite. CNTs are widely accepted nanocarriers in the field of drug delivery and in biomedical application. For pharmaceutical use, the CNTs produced must be of good quality, free from impurities and carbonaceous matter and should not have damaged structures. The purpose of this paper is to compare usage of single and multi walled carbon nanotubes in drug delivery. Plus this paper also demonstrates advantages and disadvantages of using CNTs in drug delivery.

Comparison

Single wall (SWCNT) are composed of carbon atoms arranged in a hexagonal lattice cylindrical, so that its structure is the same that would be obtained if rolled up on itself a sheet of graphite. Their ends may be closed for half fullerene sphere or may be open. The Multiple walled (MWCNT) have a structure similar to several Concentric SWCNT with different diameters. In both cases the main feature, which will result in a number of outstanding properties, is that showing a ratio length / diameter very high: its diameter is about nanometers and its length can vary from a few microns to millimeters or even few centimeters (Baddour , 3).

The MWCNT were discovered in 1991 by Sumio Iijima, a Japanese engineer NEC company. From the beginning showed significant quantum effects due to its almost one-dimensional structure, which encouraged many scientists to work in them. The SWCNT were discovered two years later by Iijima in the NEC group and another group at the IBM Almaden Laboratory. In drug delivery both (SWCNT and MWCNT) show different properties. Also depend heavily on its dimensions (diameter and length) and the defects present in the nanotube (vacancies or impurities occupying the place of a carbon atom, deformation, bending,). But depend on the manner in which the hexagons are arranged from the sheet of graphite, ie how to roll up the hypothetical graphite sheet resulting in our nanotube. Hamada indices (n, m) quantify this quality of nanotubes carbon, resulting in three groups: armchair nanotubes (n = m) nanotubes zigzag (m = 0) and chiral nanotubes (n ? m ? 0) (Kleinsorge, 1416).

In SWNTs only one sheet of graphene is arranged to give a cylindrical structure which is one atom thick, having a radius of up to 1 nm. The SWNTs are closed at both ends with cap-like structures ...