Central Leather Research Institute Council of Scientific and Industrial Research

Adyar, India

Central Leather Research Institute Council of Scientific and Industrial Research

Adyar, India
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Dhana lekshmi U.M.,Central Leather Research Institute Council of Scientific and Industrial Research | Poovi G.,Central Leather Research Institute Council of Scientific and Industrial Research | Kishore N.,Central Leather Research Institute Council of Scientific and Industrial Research | Reddy P.N.,Central Leather Research Institute Council of Scientific and Industrial Research
International Journal of Pharmaceutics | Year: 2010

With the objective to achieve prolonged drug release, especially for the treatment of diabetes mellitus, and thereby to reduce the side effects of administration of conventional dosage form, repaglinide loaded PMMA nanoparticles have been formulated. These nanoparticles have been developed by solvent evaporation method and were subjected to various studies for characterization including photon correlation spectroscopy (PCS), scanning electron microscopy (SEM) and X-ray diffraction (XRD). These studies favorably revealed that the mean particle diameter of optimized formulation was 108.3. nm and had spherical morphology with amorphous nature.Moreover, these particles were also subjected to Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC) and thermo gravimetric analysis (TGA) for compatibility analysis between drug and polymer. The results were positive and showed that, there were no interaction between drug and polymer. The optimized formulation demonstrated favorable in vitro prolonged release characteristics. Experimental in vitro release data were substituted with available mathematical models to establish the mechanism of release of repaglinide and was found to follow zero order, diffusion and erosion mechanisms.The in vivo toxicity study in albino rats showed no significant change in biochemical and pathological examinations. Hence, the designed system could possibly be advantageous in terms of prolonged release, to achieve reduced dose frequency and improve patient compliance of repaglinide. © 2010 Elsevier B.V.


Rajam M.,Central Leather Research Institute Council of Scientific and Industrial Research | Pulavendran S.,Central Leather Research Institute Council of Scientific and Industrial Research | Rose C.,Central Leather Research Institute Council of Scientific and Industrial Research | Mandal A.B.,Central Leather Research Institute Council of Scientific and Industrial Research
International Journal of Pharmaceutics | Year: 2011

Growth factors are essential in cellular signaling for migration, proliferation, differentiation and maturation. Sustainable delivery of therapeutic as well as functional proteins is largely required in the pharmacological and regenerative medicine. Here we have prepared chitosan nanoparticles (CNP) and incorporated growth factors such as epidermal growth factor (EGF) and fibroblast growth factor (FGF), either individually or in combination, which could ultimately be impregnated into engineered tissue construct. CNP was characterized by Fourier transform infrared (FTIR) spectroscopy, Zeta sizer and high resolution transmission electron microscope (HRTEM). The particles were in the size range of 50-100 nm with round and flat shape. The release kinetics of both EGF and FGF incorporated CNP showed the release of growth factors in a sustained manner. Growth factors incorporated nanoparticles did not show any toxicity against fibroblasts up to 4 mg/ml culture medium. Increased proliferation of fibroblasts in vitro evidenced the delivery of growth factors from CNP for cellular signaling. Western blotting results also revealed the poor inflammatory response showing less expression of proinflammatory cytokines such as IL-6 and TNFα in the macrophage cell line J774 A-1. © 2011 Elsevier B.V. All rights reserved.


Indumathy R.,Central Leather Research Institute Council of Scientific and Industrial Research | Weyhermuller T.,Max Planck Institute for Chemistry | Nair B.U.,Central Leather Research Institute Council of Scientific and Industrial Research
Dalton Transactions | Year: 2010

Two new mixed ligand complexes of cobalt(iii) containing ancillary biimidazole ligands, [Co(phen)2H2biim](ClO 4)3·0.5(H7O3)(ClO 4) (1) and [Co(bpy)2H2biim](ClO 4)3·3H2O (2) have been synthesized and characterized by various spectroscopic and electrochemical techniques. Both complexes 1 and 2, have been characterized by the single crystal X-ray diffraction method. While cobalt complex 1 was found to crystallize in the triclinic system with the P1 space group, complex 2 was found to crystallize in the orthorhombic system with the Pbca space group. The unit cell packing of complex 1 shows the presence of a water cluster, which is buttressed by oxygen atoms present in the perchlorate anions and water with an average O⋯O bond distance of 2.41-2.86 Å. Interaction of these complexes with calf thymus DNA (CT-DNA) was investigated by electronic spectral titrations. The results suggest that complexes 1 and 2 bind to DNA through the groove via hydrogen bonding. This is due to the presence of -NH in the ancillary ligand biimidazole, which favors hydrogen bonding with DNA base pairs. The intrinsic DNA binding constant values for complexes 1 and 2 were found to be (5.18 ±0.23) × 104 M-1 and (1.26 ± 0.13) × 104 M-1 respectively. Groove binding of these complexes with DNA is further supported by viscosity measurements, thermal denaturation and circular dichroism studies. Among the two cobalt complexes, complex 1 possesses greater DNA binding strength due to the presence of the conjugated aromatic structure of the phen ligand which increases the hydrophobic interactions with DNA. DNA cleavage experiments using plasmid DNA pUC 18 show that these complexes exhibit efficient photonuclease activity in the presence of molecular oxygen. © 2010 The Royal Society of Chemistry.


Sathyaraj G.,Central Leather Research Institute Council of Scientific and Industrial Research | Nair B.U.,Central Leather Research Institute Council of Scientific and Industrial Research
Inorganica Chimica Acta | Year: 2013

Two ruthenium(II) mixed ligand complexes [Ru(bpy)2(imiphen)] (PF6)2, 1 and [Ru(bpy)2(phimiphen)](PF 6)2, 2, where imiphen = 2-(1H-imidazol-2yl)-1H-imidazo[4, 5-F][1,10]phenanthroline and phimiphen = 2-(1H-benzimidazol-2yl)-1H-imidazo[4,5- F][1,10]phenanthroline have been synthesized and characterized using various spectroscopic techniques like ESI mass, electronic spectroscopy and fluorescence spectroscopy. Both these complexes exhibit unusual fluorescence spectra. Complexes 1 and 2 show emission maxima at 620 and 617 nm when excited at their MLCT band at 450 nm. The emission intensity has been found to depend on the nature of the solvent. Emission intensity of the aqueous solution of complexes 1 and 2 has been found to be 75-143% greater than the emission intensity of acetonitrile solution of these two complexes. This increase in the emission intensity in aqueous solution is accompanied by an increase in the lifetime of the excited state of the complex in aqueous solution. Emission intensity increase observed for these complexes is due to the involvement of the H 2O molecule in the hydrogen bonding with imidazole N-H of the ligand, making the ligand rigid. On the other hand, in acetonitrile medium because of lack of hydrogen bonding, the imidazole ring can have free rotation. © 2013 Published by Elsevier B.V.


Gnanasekaran D.,Central Leather Research Institute Council of Scientific and Industrial Research | Walter P.A.,Central Leather Research Institute Council of Scientific and Industrial Research | Reddy B.S.R.,Central Leather Research Institute Council of Scientific and Industrial Research
Polymer Engineering and Science | Year: 2013

A series of new hexafluoroisopropylidene, isopropylidene, carbonyl, and ether moieties substituted polyamides have been prepared from aromatic diamines and various moieties substituted aromatic dianhydrides. The synthesized polyamides were readily soluble in polar solvents such as N-methyl-2- pyrrolidone, N,N-dimethylacetamide, N,N-dimethylformamide, and dimethyl sulfoxide. These polyamides exhibited good thermal stability and high char yields. The chemical and physical properties of the newly prepared polyamide-polyhedral oligomeric silsequioxanes (PA-POSS) were compared in terms of their chemical structures and thermal properties. The morphological properties of the polymeric nanocomposites depend both on their chemical structure of dianhydride and the aggregation of POSS were investigated by scanning electron microscopy, transmission electron microscopy, and atomic force microscopy. Polyamides with bulky POSS and fluoro groups can effectively decrease dielectric constants. The dielectric constants of PA-POSS were found to be decreased from 3.75 to 3.29 by changing the substitution. These polyamides showed good thermal stability up to 353 °C for a 10 % weight loss. The fluorinated polyamides have relatively higher thermal stability than the polyamides without halogen because of high bond energy of C-F bond. The fiuorinated groups in the polymer backbone have played an important role in the improvement of dielectric performance of polymers. Copyright © 2012 Society of Plastics Engineers.


Murali R.,Central Leather Research Institute Council of Scientific and Industrial Research | Thanikaivelan P.,Central Leather Research Institute Council of Scientific and Industrial Research
RSC Advances | Year: 2016

Bionic collagen-poly(dialdehyde) locust bean gum based hybrid scaffolds synergistically combined with vascular endothelial growth factor were prepared to regenerate tissue formation for wound healing applications. The dialdehyde functionalities introduced in the locust bean gum were responsible for the improved collagen stability, biostability and immobilization of vascular endothelial growth factor in the hybrid scaffolds. In vitro Swiss 3T6 mouse fibroblast cell culture studies reveal that the prepared hybrid scaffolds have enhanced cell viability and infiltration. An in vivo wound healing study demonstrates that the collagen-poly(dialdehyde) locust bean gum-vascular endothelial growth factor hybrid scaffolds boost the level of fibroblast and neovascular content as well as collagen deposition; complete epithelialization occurs within 16 ± 0.9 days. The results show that the vascular endothelial growth factor immobilized hybrid scaffold induces chemotactic effects to promote rapid tissue regeneration and wound repair, thereby demonstrating its potential for burn wounds, chronic wounds and diabetic foot ulcer treatments. © The Royal Society of Chemistry 2016.


Cheirmadurai K.,Central Leather Research Institute Council of Scientific and Industrial Research | Biswas S.,Central Leather Research Institute Council of Scientific and Industrial Research | Murali R.,Central Leather Research Institute Council of Scientific and Industrial Research | Thanikaivelan P.,Central Leather Research Institute Council of Scientific and Industrial Research
RSC Advances | Year: 2014

We report large-scale biosynthesis of copper nanoparticles using an extract of henna leaves as reductant. Due to the substantial electrical conductivity of the calcined copper nanoparticles, we used them to prepare conductive nanobiocomposites utilizing collagen waste. We demonstrate that the nanobiocomposites, when inserted between batteries, illuminate a light emitting diode lamp. © the Partner Organisations 2014.


Nethaji S.,Central Leather Research Institute Council of Scientific and Industrial Research | Nethaji S.,Institute of Chemical Technology | Sivasamy A.,Central Leather Research Institute Council of Scientific and Industrial Research | Thennarasu G.,Central Leather Research Institute Council of Scientific and Industrial Research | Saravanan S.,Institute of Chemical Technology
Journal of Hazardous Materials | Year: 2010

In the present study, chemically prepared activated carbon derived from Borassus aethiopum flower was used as adsorbent. Batch adsorption studies were performed for the removal of Malachite Green (MG) from aqueous solutions by varying the parameters like initial solution pH, adsorbent dosage, initial MG concentration and temperature with three different particle sizes such as 100μm, 600μm and 1000μm. The zero point charge was 2.5 and the maximum adsorption occurred at the pH range from 6.0 to 8.0. Experimental data were analyzed by model equations such as Langmuir, Freundlich and Temkin isotherms and it was found that the Langmuir isotherm model best fitted the adsorption data. Thermodynamic parameters such as Δ G, Δ H and Δ S were also calculated for the adsorption processes. Adsorption rate constants were determined using pseudo first-order, pseudo second-order rate equations and also Elovich model and intraparticle diffusion models. The results clearly showed that the adsorption of MG onto PFAC followed pseudo second-order model and the adsorption was both by film diffusion and by intraparticle diffusion. © 2010 Elsevier B.V.


Wegene J.D.,Addis Ababa Institute of Technology | Thanikaivelan P.,Central Leather Research Institute Council of Scientific and Industrial Research
Industrial and Engineering Chemistry Research | Year: 2014

Leather is a unique consumer material possessing a variety of properties such as strength, viscoelasticity, flexibility, and longevity. However, the use of leather for smart product applications is a challenge since it is an electrically insulating material. Here, we report a simple method to produce conducting leathers using an in situ polymerization of pyrrole. The concentrations of pyrrole, ferric chloride, and anthraquinone sulfonic acid and the number of polymerization were optimized to produce maximum conductivity in the treated leathers. The coating of polypyrrole in the treated leathers was probed using Fourier transform infrared spectroscopy, X-ray diffraction, and electron microscopic analysis. We also show that the treated leathers are black through re flectance measurements, thereby suggesting that the use of toxic and expensive dyes can be avoided for coloration process. We further demonstrate that the treated leathers, with a maximum conductivity of 7.4 S/cm, can be used for making conductive gloves for operating touch-screen devices apart from other smart product applications. © 2014 American Chemical Society.


Ragothaman M.,Central Leather Research Institute Council of Scientific and Industrial Research | Palanisamy T.,Central Leather Research Institute Council of Scientific and Industrial Research | Kalirajan C.,Central Leather Research Institute Council of Scientific and Industrial Research
Carbohydrate Polymers | Year: 2014

Here we report the preparation of collagen-poly(dialdehyde) guar gum based hybrid functionalized scaffolds covalently immobilized with platelet derived growth factor - BB for tissue engineering applications. Poly(dialdehyde) guar gum was synthesized from selective oxidation of guar gum using sodium periodate. The synthesized poly(dialdehyde) guar gum not only promotes crosslinking of collagen but also immobilizes the platelet derived growth factor through imine bonds. The covalent crosslinking formed in collagen improves thermal, swelling and biodegradation properties of the hybrid scaffolds. The prepared hybrid scaffolds show 3D interconnected honeycomb porous structure when viewed under a microscope. The release of immobilized platelet derived growth factor was seen up to 13th day of incubation thereby proving its sustained delivery. The developed hybrid scaffold leads to a quantum increase in NIH 3T3 fibroblast cell density and proliferation thereby demonstrating its potential for tissue engineering applications. © 2014 Elsevier Ltd.

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