Development, characterization and evaluation of the biocompatibility of catechol crosslinked horsegram protein films

Abstract

Proteins in the common legume Macrotyloma uniflorum have inherent antimicrobial properties and can be converted into films for food, medical and other applications. Crude proteins were extracted from horsegram seeds and were converted into thin films by casting approach. Amino acid analysis of the extracted protein confirmed the presence of both essential and non- essential amino acids required for food applications. However, the protein films have relatively weak mechanical properties and poor aqueous stability which can be substantially improved by crosslinking with a biocompatible crosslinker, catechol. Crosslinked films had strength of 7.32 MPa and were stable in water and cell culture media for upto 4 days suggesting their suitability for tissue engineering and other medical applications. The swelling % of the films was directly proportional to the amount of catechol used. The 20% catechol crosslinked films displayed significant antibacterial activity against Bacillus cereus and E. coli in comparison to the uncrosslinked films. In addition to demonstrating good antifungal activity against Aspergillus niger, the films were conducive to the growth of L929 mouse fibroblast cells, better than Zn @20 ppm. Overall, large availability, presence of essential amino acids, ability to develop films and other biomaterials with desired properties and cytocompatibility make horsegram proteins desirable for food, medical and other applications.