Synthesis and evaluation of protein-based biopolymer in production of silver nanoparticles as bioactive compound versus carbohydrates-based biopolymers

This overall process deals with evaluating the performance of silver nanoparticles, synthesized from sodium caseinate (SC) as green biological active agent, in comparison with widely produced from carboxymethyl cellulose, other carbohydrates (oxidized nanocellulose fibres (OC) and starch (St)). The TGA, FTIR and TEM, as well as its antimicrobial activities toward pathogenic Gram-positive and Gram-negative bacteria in addition to the yeast strain Candida albicans NRRL Y-477 were examined. In addition, with regard to their anti-tumour activity, the evaluation was studied via many cancer cell lines against RPE1 (normal retina cell line). The results revealed that the SC–Ag(I) and CMC–Ag(I) complexes were formed in six- and five-membered chelate rings, respectively, as nanoparticles, while linear chelation structure was formed in case of OC–Ag(I) and St–Ag(I) complexes. The complexation of SC with Ag(I) ions was recommended as promising stable and antimicrobial agent, with lower free Ag(I) ions and particle size than other Ag-complexes. Moreover, it provided anti-tumour activity of most tested cell lines (in vitro), with the following sequence HCT116 > PC3 > HePG 2 > MCF-7 > A549 with IC(50) and IC(90) values of 25.8 and 54.73 µg ml(−1), 45.1 and 66.7 µg ml(−1), 64.3 and 110.7 µgml(−1), 71.4 and 114.8 µgml(−1) and 80.1 and 127.7 µgml(−1), respectively. The promising effect of SC–Ag complex was also clear from its selective index versus RPE1 (normal retina cell line).