Biological applications of biogenic silk fibroin–chitosan blend zinc oxide nanoparticles.

For the synthesis of zinc oxide nanoparticles, a bioactive, cost-effective, and sustainable material such as the chitosan/silk fibroin blend was developed. The current research was aimed to elucidate the antibacterial activity of silk fibroin–chitosan blend ZnO NPs at various pH (4, 8 and 12) and temperatures (4, 37, and 50 °C) against gram-negative (Klebsiella pneumoniae, Escherichia coli, Serratia rubidaea, and Proteus mirabilis) and gram-positive bacterial strains (Staphylococcus aureus, Bacillus thuringensis, Bacillus licheniformis, and Clostridium difficile) at numerous concentrations (2–8 mg/ml). Agar well diffusion method was used to evaluate the antibacterial effect by measuring the zone of inhibition. Silk fibroin–chitosan blend ZnO NPs significantly reserved the growth of gram-negative bacterial strains, e.g., K. pneumoniae (11.3 ± 0.9 mm), E. coli (12.7 ± 0.9 mm), S. rubidaea (16.7 ± 0.9 mm), and P. mirabilis (11.7 ± 1.2 mm) and gram-positive bacterial strains such as B. thuringiensis (12.3 ± 0.3 mm), B. licheniformis (10.0 ± 0.57 mm), S. aureus (17.3 ± 1.2 mm), and C. difficile (11.7 ± 1.2 mm). At various temperatures and various pH values (acidic and basic), the stability of silk fibroin–chitosan blend ZnO NPs was observed. Silk fibroin–chitosan blend ZnO NPs significantly inhibited the growth of all bacterial strains at 37°C, and a maximum zone of inhibition was found at pH 8. The formation of SFCH blend ZnONPs was confirmed via numerous characterization techniques such as ultraviolet visible spectrum, Fourier transform infrared spectroscopy (FTIR), X-ray diffraction, and transmission electron microscopy (TEM). Transmission electron microscopy revealed that SFCH blend ZnONPs were highly stabilized and homogeneously distributed in the solution, and the average particle size was about 30.06 nm with a spherical shape. We concluded that silk fibroin–chitosan zinc oxide nanocomposite could be a safe and promising antimicrobial agent for wound dressing and various applications in biomaterials. [ABSTRACT FROM AUTHOR]