Novel Smart Polymer Based In Situ Gels

Download or read book Novel Smart Polymer Based In Situ Gels written by Laxmi R. Fogueri and published by . This book was released on 2010 with total page 138 pages. Available in PDF, EPUB and Kindle. Book excerpt: The objectives of this investigation were to investigate the effect of interaction of protein and polymers with varying end groups on the overall release profile of model proteins (Lysozyme, Bromelain and Bovine Serum Albumin (BSA)). Lactide and/or glycolide-based polymers (intrinsic viscosity 0.15 to 0.22 d/L) differing in end groups (carboxylic acid or ester), were dissolved in an organic solvent mixture of various ratios of benzyl benzoate and benzyl alcohol. Polymer solutions were tested for injectability through 22 gauge needle. The model proteins were incorporated into the polymer solution by sonicating at 40W for 20 seconds. When polymer-protein solution was injected in releasing media (phosphate buffered saline, pH 7.4), it instantaneously formed a gel depot. Samples were withdrawn from the releasing media at specific time points and analyzed for the protein content as well as its conformational stability and biological activity. Lysozyme and Bromelain content was determined at 280 nm while BSA contents were determined at 277.8 nm by using a UV spectrophotometer. Conformational stability was determined by Fourier Transform Infra Red (FTIR) Spectroscopy and Differential Scanning Calorimeter (DSC). The peaks in the range of 1620-1695nm in FTIR spectrum were indicative of secondary structures of the model proteins. Enthalpy and mid-point of thermal transition in DSC thermogram were used as thermodynamic parameters indicating conformational stability. Biological activity was determined by enzyme activity assay using Micrococcus Lysodeikticus as substrate for Lysozyme, Tyrosinase for albumin, and Z-L-Lys-ONp hydrochloride for Bromelain