Chemistry

The healing of critical sized segmental defects is an ongoing clinical problem. No method has achieved pre-eminence. The Masquelet technique is a relatively new innovation involving the induction of a fibrous tissue membrane around the bone defect site taking advantage of the body's foreign body reaction to the presence of a polymethylmethacrylate (PMMA) spacer. The aim of this study was to investigate the properties and characteristics of this induced membrane and its effectiveness when used in conjunction with allograft or an allograft/autograft mix as filler materials in an ovine critical sized defect model. The resultant induced membrane was found to be effective in containing the graft materials in situ. It was demonstrated to be an organised pseudosynovial membrane which expressed bone morphogenic protein 2 (BMP2), transforming growth factor-beta (TGFβ), vascular endothelial growth factor (VEGF), von Willerbrand factor (vWF), interleukin 6 (IL-6) and interleukin 8 (IL-8). ...

Proteases are involved in several crucial biological processes and reported to have important physiological functions. They also have multifarious applications in different industries. The immobilized form of the enzyme further improves its industrial applicability. Here, we report covalent immobilization of a novel cysteine endopeptidase (procerain B) on amberlite MB-150 beads through glutaraldehyde by Schiff base linkage. The immobilized product was examined extensively by Fourier Transform Infrared Spectroscopy (FTIR), Scanning electron microscopy (SEM) and Energy Dispersive X-ray (EDX) analysis. The characterization of the immobilized product showed broader pH and thermal optima compared to the soluble form of the enzyme. The immobilized form of procerain B also showed lower Km (180.27±6 µM) compared to the soluble enzyme using azocasein as substrate. Further, immobilized procerain B retains 38.6% activity till the 10(th) use, which strongly represents its industrial candidature.

Di-tert-butyl-peroxide (DTBP) is a clear organic compound and one of the most stable organic peroxides, formed by the linkage of two flanking tert-butyl groups to a peroxide group. A versatile compound, DTBP is used as a radical initiator in polymer chemistry and organic synthesis, and is a cetane improver in diesel fuel, raising its ignition accelerations. It owes a great deal of its usefulness to the nature of its decomposition, or homolysis; it breaks down at temperatures greater than 100 degrees celsius, and because it can decompose both aerobically and anaerobically, it makes for a multifaceted fuel source. The following is a list of some of the many applications of DTBP: • An important initiator for high pressure, high temperature polymerizations of ethylene and halogenated ethylenes. • Cures resins of allyl acetate and allyl phthalate. • Applied in the making of polyketones from carbon and ethylene • Used as a finishing catalyst for polystyrene • Used as a polymerization cata...

Near-Infrared (NIR) fluorescence has been valuable in analytical and bioanalytical chemistry. NIR probes and labels have been used for several applications, including hydrophobicity of protein binding sites, DNA sequencing, immunoassays, CE separations, etc. The NIR region (700-1100 nm) has advantages for the spectroscopist due to the inherently lower background interference from the biological matrix and the high molar absorptivities of NIR chromophores. During the studies we report here several NIR dyes were prepared to determine the role of the hydrophobicity of NIR dyes and their charge in binding to amino acids and proteins, e.g., serum albumins. We synthesized NIR dye homologs containing the same chromophore but substituents of varying hydrophobicity. Hydrophobic moieties were represented by alkyl and aryl groups. These NIR dyes of varying hydrophobicity exhibited varying degrees of H-aggregation in aqueous solution indicating that the degree of H-aggregation could be used as an indicator to predict binding characteristics to serum albumins. In order to understand what factors may be important in the binding process, spectral behavior of these varying hydrophobicity dyes were examined in the presence of amino acids. Typical dye structures that exhibit large binding constants to biomolecules were compared in order to optimize applications utilizing non-covalent interactions.