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Thiruvananthapuram, India

The present study describes the synthesis of different mole densities of poly(propylene glycol)dimethacrylate cross-linked resins using monomer units such as styrene and 4-chloromethyl styrene and its evaluation as an ideal support toward different stages of solid-phase peptide synthesis. Free radical generated aqueous suspension polymerization has been followed for polymerization and the formation of resin was characterized using infrared and carbon-13 spectroscopic techniques. Surface morphology of resin was examined by scanning electron microscopy. The polymerization reaction was investigated with respect to the effect of amount of cross-linking agent to verify the swelling, loading, and the mechanical stability of resin. Solvent imbibition abilities in commonly used solvents were measured and compared to commercially available Merrifield as well as reported styrene-acryloyloxyhydroxypropyl methacrylate-tripropyleneglycol diacrylate (SAT resins. The chemical inertness of the support was also checked with different reagents used for solid-phase peptide synthesis. The suitability of support was demonstrated by synthesizing biologically potent Endothelin class of linear peptides by Fmoc strategy and compared to SAT resin. The purities of synthetic peptides were analyzed by high-performance liquid chromatography and corresponding masses by matrix-assisted laser desorption/ionisation-time of flight analysis. Copyright © 2012 Wiley Periodicals, Inc. Source

Aghila Rani K.G.,Sree Chitra Tirunal Institute for Medical Science and Technology | Kartha C.C.,Rajiv Gandhi Center for Biotechnology
Growth Factors

Recent studies have provided evidence that the human heart has an endogenous reserve of cardiac stem cells (CSCs) that can be activated to reconstitute the dead myocardium. Current efforts are now directed towards the identification of factors favoring the growth and expansion of the CSC pool in the heart. Accordingly, in the present study, effects of different growth factors on cardiosphere-derived cells (CDCs), expanded from atrial biopsies from patients undergoing elective coronary artery bypass surgery, were analyzed. CSCs appear to respond to epidermal growth factor (EGF) more efficiently than other widely used growth factors such as vascular endothelial growth factor, insulin-like growth factor, basic fibroblast growth factor, hepatocyte growth factor, transforming growth factor, and platelet-derived growth factor. EGF significantly promoted cardiosphere formation (p < 0.05) and proliferation (p < 0.005), migration (p < 0.0005), and wound healing (p < 0.005) activities of CDCs in comparison to the other growth factors studied. Pretreatment with EGF enhanced the expression of cardiac markers cTN1 + and MHC+ in CDCs in comparison to untreated controls. © 2010 Informa UK Ltd. Source

Joseph I.,Rajiv Gandhi Center for Biotechnology
Journal of Public Health Policy

Developing countries are at risk of importing Middle East Respiratory Syndrome Corona Virus (MERS CoV) from the Middle East. Hospitals in the Middle East currently reporting the disease are staffed by immigrants. In the current hot spots for MERS CoV a sizeable portion of the population is from other countries, but many of these countries have yet to detect any importation of MERS CoV. To assess the disease transmission in these countries, supplemental surveillance strategies are urgently needed beyond the currently recommended measures. A few strategies to address the situation are: (i) improving preparedness with enhanced surveillance in particular regions; (ii) targeting certain sentinel groups for surveillance in hot spots; and (iii) limited use of serosurveillance. Recovered, immune patients can be employed to give patient care during outbreaks. © 2015 Macmillan Publishers Ltd. Source

Nair K L.,Rajiv Gandhi Center for Biotechnology
International journal of nanomedicine

Nanoscaled devices have great potential for drug delivery applications due to their small size. In the present study, we report for the first time the preparation and evaluation of antitumor efficacy of 5-fluorouracil (5-FU)-entrapped poly (D, L-lactic-co-glycolic acid) (PLGA) nanoparticles with dependence on the lactide/glycolide combination of PLGA. 5-FU-loaded PLGA nanoparticles with two different monomer combinations, 50-50 and 90-10 were synthesized using a modified double emulsion method, and their biological evaluation was done in glioma (U87MG) and breast adenocarcinoma (MCF7) cell lines. 5-FU-entrapped PLGA 50-50 nanoparticles showed smaller size with a high encapsulation efficiency of 66%, which was equivalent to that of PLGA 90-10 nanoparticles. Physicochemical characterization of nanoparticles using differential scanning calorimetry and X-ray diffraction suggested the presence of 5-FU in molecular dispersion form. In vitro release studies showed the prolonged and sustained release of 5-FU from nanoparticles with both the PLGA combinations, where PLGA 50-50 nanoparticles showed faster release. Nanoparticles with PLGA 50-50 combination exhibited better cytotoxicity than free drug in a dose- and time-dependent manner against both the tumor cell lines. The enhanced efficiency of PLGA 50-50 nanoparticles to induce apoptosis was indicated by acridine orange/ethidium bromide staining. Cell cycle perturbations studied using flow cytometer showed better S-phase arrest by nanoparticles in comparison with free 5-FU. All the results indicate that PLGA 50-50 nanoparticles possess better antitumor efficacy than PLGA 90-10 nanoparticles and free 5-FU. Since, studies have shown that long-term exposure of ailing tissues to moderate drug concentrations is more favorable than regular administration of higher concentration of the drug; our results clearly indicate the potential of 5-FU-loaded PLGA nanoparticles with dependence on carrier combination as controlled release formulation to multiplex the therapeutic effect of cancer chemotherapy. Source

Dutta D.,Rajiv Gandhi Center for Biotechnology
International Journal of Developmental Biology

Embryonic Stem Cells (ESCs) are derived from the inner cell mass of blastocysts. They have the unique potency to differentiate into diverse lineages. Hence, they are bestowed with the term pluripotency. Several mechanisms have been implicated in maintaining the pluripotency of ESCs. This review will focus on the role of signaling pathways in regulating ESC pluripotency among diverse mammalian species. A novel phylogenetic approach has been designed to understand the structural basis of divergence in the signaling pathways which modulate pluripotency among different species. Detailed insight into different signaling mechanisms indicates inhibition of Extracellular Related Kinase 1/2 (ERK 1/2) signaling as the key component regulating the pluripotency of ESCs. On the basis of recent advances made in this field, it can be hypothesized that expression of the transcription factor KLF4 and inhibition of ERK signaling may promote the establishment and maintenance of true ESCs from different mammalian species. © 2013 UBC Press. Source

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