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ImatiniB (IB) mesylate, an oncological drug, is designated chemically as
4-[(4-methyl-piperazin-1-yl)methyl]-N-[4-methyl-3-[(4-pyridin-3-yl-pyrimidin-2-yl)-amino]
-phenyl]-benzamide methane sulfonate. It is an important drug used to treat certain
types of cancers (Melo and Chah, 2007). It acts as a specific inhibitor of many tyrosine
kinases. Chronic mylogenous leukemia is an unusual cancer because a single mutation is
initially responsible. The protein encoded by Bcr-Abl is an unregulated tyrosine kinase
that continuously signals cell division, and controlling Bcr-Abl could control the cancer.
Bcr-Abl is actually a fusion of two different genes. Nanosilver aggregation gives
coupled plasmon absorbance, and so the resulted absorbance is different from the uncoupled
one (Basu et al., 2007). This interparticle coupling effect becomes very important in the
study of particle plasmon resonances. The aggregation of metal nanoparticles induced by
drugs has attracted significant interest as drug recognition systems (Li et al., 2005). This forms the basis for the famous latex test (Singer, 1956). The optical properties of the
metal nanoclusters are different in the native metal, and adsorbed drugs on the nanometal
will give rise to enhanced Raman signal called Surface Enhanced Raman Scattering
(SERS) (Jeanmaire and Van Duyne, 1977). This feature is used by many drug studies like
detection at low concentration level to understand the adsorption behavior of the drug on the
tissue surface (Kneipp et al., 1999). In this study, such nanosilver aggregation of
silver nanoparticles in the silver colloid and nanosilver-coated filter paper by UV-visible
spectra, SERS and the Scanning Electron Microscopy (SEM) techniques has been studied
for finding the possibility of drug detection using the above said surface
instrumental techniques.
The drug ImatiniB (IB) was obtained from a pharmaceutical lab and used
as-received. Tetra methyl orthosilicate, sodium chloride, methanol, silver nitrate were of
analytical grade and used as-received. Silver sol was prepared by the procedure reported by Lee
and Miesel (1982). Ag-coated filter paper was prepared by the known method (Cabalin
and Laserna, 1995). UV-visible spectra were measured on Shimadzu UV-160A
spectrometer. FT-Raman spectra were recorded in the region of 100-4,000
cm_1 using IFS-200 dispersive Raman spectrometer which uses 1,064 nm laser as the excitation source. SEM
pictures were taken using JSM-JEOL SEM 5610 LV
microscope. |
