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Reddy M.K.,Svuniversity | Reddy K.S.,Svuniversity | Narasimhaswamy T.,CSIR - Central Leather Research Institute | Das B.B.,Indian Institute of Science | And 3 more authors.
New Journal of Chemistry | Year: 2013

Hydrogen bonding is the most important non-covalent interaction utilised in building supramolecular assemblies and is preferred often as a means of construction of molecular, oligomeric as well as polymeric materials that show liquid crystalline properties. In this work, a pyridine based nematogenic acceptor has been synthesized and mixed with non-mesogenic 4-methoxy benzoic acid to get a hydrogen bonded mesogen. The existence of hydrogen bonding between the pyridyl unit and the carboxylic acid was established using FT-IR spectroscopy from the observation of characteristic stretching vibrations of unionized type at 2425 and 1927 cm-1. The mesogenic acceptor and the complex have been investigated using 13C NMR in solution, solid and liquid crystalline states. Together with the 2D separated local field NMR experiments, the studies confirm the molecular structure in the mesophase and yield the local orientational order parameters. It is observed that the insertion of 4-methoxy benzoic acid not only enhances the mesophase stability but also induces a smectic phase due to an increase in the core length of the hydrogen bonded mesogen. © 2013 The Royal Society of Chemistry and the Centre National de la Recherche Scientifique.


Ranjithkumar A.,Academy of Scientific and Innovative Research AcSIR | Durga J.,Academy of Scientific and Innovative Research AcSIR | Ramesh R.,CSIRCentral Leather Research Institute | Rose C.,CSIRCentral Leather Research Institute | Muralidharan C.,CSIRCentral Leather Research Institute
Environmental Science and Pollution Research | Year: 2016

The conventional unhairing process in leather making utilises large amount of lime and sodium sulphide which is hazardous and poses serious waste disposal concerns. Under acidic conditions, sodium sulphide liberates significant quantities of hydrogen sulphide which causes frequent fatal accidents. Further, the conventional unhairing process involves destruction of the hair leading to increased levels of biological oxygen demand (BOD), chemical oxygen demand (COD), total dissolved solids (TDS) and total suspended solids (TSS) in the effluent. A safe approach is needed to overcome such environmental and health problems through an eco-benign process. The present study deals with a clean technology in which the keratinous body is detached from the dermis using enzymes produced from Bacillus crolab MTCC 5468 by solid state fermentation (SSF) as an alternative to noxious chemicals. Complete unhairing of skin could be achieved with an enzyme concentration of 1.2 % (w/w). The bio-chemical parameters of the spent liquor of the enzymatic process were environmentally favourable when compared with conventional method. The study indicates that the enzymatic unhairing is a safe process which could be used effectively in leather processing to alleviate pollution and health problems. © 2016 Springer-Verlag Berlin Heidelberg


Gopal Shankar K.,CSIRCentral Leather Research Institute | Udhaya Kumar S.,CSIRCentral Leather Research Institute | Sowndarya S.,CSIRCentral Leather Research Institute | Suresh Babu P.,CSIRCentral Leather Research Institute | Rose C.,CSIRCentral Leather Research Institute
Journal of Biomaterials Applications | Year: 2016

Bovine rumen is hitherto considered as an inedible waste of meat industry. The rumen tissues can be used as an alternative source of collagen to produce biocompatible materials for clinical application. In an effort to develop a functional biomaterial from the inedible mammalian tissues, this study aims to isolate and characterize bovine rumen submucosa. Initially, the rumen tissue was sequentially processed using chemical and enzymatic treatment to decellularize, neutralize, stabilize, and to produce a native collagen matrix which is referred as collagen film (COL-F). Thus, prepared matrix was treated with 1% (w/v) chitosan solution to produce a hybrid film which is referred as collagen-chitosan film (COL/CS-F). The comparative study includes the evaluation of physical, chemical, and biological properties of the biofilms prepared. The surface topology of COL-F exhibited a continuous collagenous network with fibrous nature, while the chitosan treatment provided smooth plain surface to the parent film. Incorporation of chitosan in COL-F increased the tensile properties, as well as the thermal stability and durability of the films. The Fourier Transform Infrared spectroscopy results revealed the presence of respective amide peaks, which corresponds to protein (collagen), and the evidence of collagen-chitosan interlinking. The submucosa layer was electrophoretically found to have type I collagen. The X-ray diffraction data showed the presence of amorphous and crystalline peak which attributes to the triple helical structure of collagen in the films. Cytotoxicity studies on the films were performed in vitro using human keratinocytes. The results of cell viability and proliferation demonstrated that COL-F and COL/CS-F exhibit good biocompatibility and therefore can augment cell infiltration and proliferation. However, enhanced cellular activity was observed on the chitosan treated COL-F. These observations demonstrate that the biofilms prepared in this study can be used as an alternative functional biomaterial in tissue engineering. © SAGE Publications.

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