Synthesis of non-toxic, biocompatible, and colloidal stable silver nanoparticle using egg-white protein as capping and reducing agents for sustainable antibacterial application

• Published in: RSC advances Vol. 8; no. 41; pp. 23213 - 23229
• Main Authors: Thiyagarajan, Kalaiyarasan, Bharti, Vijay K, Tyagi, Shruti, Tyagi, Pankaj K, Ahuja, Anami, Kumar, Krishna, Raj, Tilak, Kumar, Bhuvnesh
• Format: Journal Article
• Language: English
• Published: England Royal Society of Chemistry 01.01.2018; The Royal Society of Chemistry
• Subjects: Antimicrobial agents; Biocompatibility; Biomedical materials; Capping; Cell membranes; Chemistry; Colloids; Conalbumin; E coli; Erythrocytes; Fruit flies; Insects; Microorganisms; Nanomaterials; Nanoparticles; Ovalbumin; Proteins; Reducing agents; Salmonella; Silver; Stability; Structural damage; Toxicity testing; Transmission electron microscopy; Viability
• ISSN: 2046-2069; 2046-2069
• DOI: 10.1039/C8RA03649G

For nearly a decade, silver nanoparticles (AgNPs) have been the most prevalent commercial nanomaterials products widely used in different biomedical applications due to their broad-spectrum antimicrobial activity. However, their poor long-term stability in different environments, namely, pH, ionic strength, and temperature, and cytotoxicity toward mammalian cells has restricted their more extensive applications. Hence, there is urgent need to develop highly biocompatible, non-toxic, and stable silver nanoparticles for wide-ranging environments and applications. In the present study, a simple, sustainable, cost-effective and green method has been developed to prepare highly stable aqueous colloidal silver nanoparticles (AgNPs-EW) using the ovalbumin, ovotransferrin, and ovomucoid of egg-white as reducing and capping agents accomplished under the irradiation of direct sunlight. Then, we evaluated the effects of freezing-drying (lyophilization) and freeze-thaw cycles on the stability of AgNPs-EW in aqueous solution under visual inspection, transmission electron microscopy, and absorbance spectroscopy. In addition, we studied the antibacterial activity against and , carried out biocompatibility studies on chicken blood, and tested acute, chronic toxicity in . The results suggest that AgNPs-EW did not aggregate upon freeze-thawing and lyophilization, thus exhibiting remarkable stability. The antibacterial activity results showed that the AgNPs-EW had the highest antibacterial activity, and the minimum inhibitory concentration (MIC) of AgNPs-EW for and were 4 and 6 μg ml , respectively. The biocompatibility study revealed that the AgNPs-EW did not induce any hemolytic effect or structural damage to the cell membranes of chicken erythrocytes up to a concentration of 12 μg ml . Similarly, no acute and chronic toxicity was observed on melanization, fecundity, hatchability, viability, and the duration of development in the 1 generation of at the concentration range of 10 mg L to 100 mg L of AgNPs-EW, and all the flies completed their full developmental cycle. Therefore, the present study successfully demonstrated the green and sustainable preparation of non-toxic AgNPs-EW having good biocompatibility, enhanced colloidal stability, and antibacterial activity. Hence, the synthesized AgNPs-EW could be used for the development of an antimicrobial formulation for controlling microbial infection.