Investigation on hydrogen bonds and conformational changes in protein/polysaccharide/ceramic based tri-component system

The main attention of presentwork is to study themolecular level interactions in the interface of biocomposite to increase their applicability. A specific kind of molecular interaction namely, hydrogen bonds play a vital role in deciding composite property. In this study, we construct a tri-component systembased on silk fibroin/sodiumalginate/hydroxyapatite by varying protein and polysaccharide proportions using in-situ co-precipitation method. The Fourier Transfer Infrared (FTIR) prediction state that prepared composite exhibit inter-(OH center dot center dot center dot N, OH center dot center dot center dot O, OH center dot center dot center dot pi) and intra-(OH center dot center dot center dot OH) molecular hydrogen bonds and their strength are varied in accordance with composition of composite. During composite preparation, conformational changes from the random coil to beta-sheet structure through intermediate beta-turns exist within the protein molecule that is confirmed by vibrational spectra. The crystallographic profile and morphology of HAP were greatly influenced by virtue of polymer matrix. Simulated body fluid (SBF) immersion study shows that biodegradation and swelling ratio are correlated with type of hydrogen bond and secondary structure of protein. Moreover, the in-vitro biomineralization, cytotoxicity and antibacterial activity of composite were analysed in detail. (C) 2020 Elsevier B.V. All rights reserved.

Automated summary

This study investigates molecular level interactions in the interface of biocomposite by focusing on hydrogen bonds and their role in determining composite properties. The prepared composite shows varying strengths of intermolecular and intramolecular hydrogen bonds, which are correlated with biodegradation and swelling ratio. Additionally, changes in protein conformation and crystallographic profile of the matrix greatly influence the properties of the composite.