Browsing by Author "Sujathan, K"

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    Aggregation induced Raman scattering of squaraine dye: Implementation in diagnosis of cervical cancer dysplasia by SERS imaging
    (BIOSENSORS & BIOELECTRONICS, 2015) Narayanan, N; Karunakaran, V; Paul, W; Venugopal, K; Sujathan, K; Maiti, KK
    The extent of squaraine dye aggregation that reflects on surface enhanced Raman signal scattering (SERS) intensity upon adsorption on nano-roughened gold surface has been investigated. Here we have synthesized a serious of six squaraine dyes consisting of two different electron donor moiety i.e. 1,1,2-trimethyl-1H-benzo[elindole and 2-methylbenzo[d]thiazole which modulates the chemisorptions and hydrophobicity being designated as SQ1, SQ2, SQ3, SQ4, SQ5 and SQ6. Interestingly, SQ2 (mono lipoic acid appended), SQ5 and SQ6 (conjugated with hexyl and dodecyl side chain) squaraine derivatives having more tendency of aggregation in DMSO-water mixed solvent showed significant increase of Raman scattering in the fingerprint region when chemisorbed on spherical gold nanoparticles. Two sets of SERS nanotags were prepared with colloidal gold nanoparticle (Au-NPs size: 40 nm) by incorporating Raman reporters SQ2 and SQ5 followed by thiolated PEG encapsulation (SH-PEG, SH-PEG-COOH) denoted as AuNPs-SQ2-PEG and AuNPs-SQ5-PEG. Further conjugation of these nanotag with monoclonal antibodies specific to over expressed receptors, EGFR and p16/Ki-67 in cervical cancer cell, HeLa showed prominent SERS mapping intensity and selectivity towards cell surface and nucleus. The fast and accurate recognition obtained by antibody triggered SERS-nanotag has been compared with conventional time consuming immunocytochemistry technique which prompted us to extend further investigation using real patient cervical smear sample for a non-invasive, ultrafast and accurate diagnosis. (C) 2015 Elsevier B.V. All rights reserved.
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    Over expression of cytosolic galectin-3 correlates with anti-apoptotic protein bcl-2: its significance in the differential diagnosis of follicular cell derived thyroid tumors in fnac
    (International Journal of Current Research, 2016-02) Shanone, CP; Jissa, VT; Shaji, T; Preethi, TR; Remani, P; Sujathan, K
    Fine Needle Aspiration Cytology is considered as a reliable and cost effective method for the initial evaluation of thyroid nodules. But it poses a diagnostic challenge in differentiating benign follicular adenoma from follicular carcinoma and follicular variant of papillary carcinoma as they have similar cytological appearance. Present study focused on the identification of an immuno marker for the differential diagnosis of thyroid malignancy and to compare the expression of Galectins and Bcl-2 to explain its role in apoptosis. We performed immunohistochemistry of galectin-1, galectin-3 and bcl-2 on cell block prepared from FNA material and corresponding tissue sections on 289 samples. Galectin-3 mRNA expression was quantified using Real time PCR. Western blotting was carried out in surgically excised fresh tissue specimens. Pap stained slides were also subjected to immunocytochemistry without de-staining. Galectin-3 was found to be highly significant (P<0.001) in the differential diagnosis of malignancy from adenoma with high diagnostic accuracy of 97.8%. All the samples of papillary carcinoma with distant metastasis showed intense expression of galectin-3 and bcl-2. A negative correlation in the expression pattern of galectin-3 and bcl-2 was observed in the case of thyroiditis. QRT- PCR revealed a significant over expression of galectin-3 (2.4 fold) in papillary carcinoma. The present study observed a correlation for the over expression of Galectin-3 with its anti-apoptotic activity and suggests galectin-3 immunohistochemistry along with morphological evaluation and quantitative assessment to eliminate unwanted thyroidectomies for benign nodules