Green fabrication of ZnO nanoparticles via spirulina platensis and its efficiency against biofilm forming pathogens.

Excessive consumption of antibiotics is considered one of the top public health threats, this necessitates the development of new compounds that can hamper the spread of infections. A facile green technology for the biosynthesis of Zinc oxide nanoparticles (ZnO NPs) using the methanol extract of Spirulina platensis as a reducing and stabilizing agent has been developed. A bunch of spectroscopic and microscopic investigations confirmed the biogenic generation of nano-scaled ZnO with a mean size of 19.103 ± 5.66 nm. The prepared ZnO NPs were scrutinized for their antibacterial and antibiofilm potentiality, the inhibition zone diameters ranged from 12.57 ± 0.006 mm to 17.33 ± 0.006 mm (at 20 µg/mL) for a variety of Gram-positive and Gram-negative pathogens, also significant eradication of the biofilms formed by Staphylococcus aureus and Klebsiella pneumoniae by 96.7% and 94.8% respectively was detected. The free radical scavenging test showed a promising antioxidant capacity of the biogenic ZnO NPs (IC50= 78.35 µg/mL). Furthermore, the anti-inflammatory role detected using the HRBCs-MSM technique revealed an efficient stabilization of red blood cells in a concentration-dependent manner. In addition, the biogenic ZnO NPs have significant anticoagulant and antitumor activities as well as minimal cytotoxicity against Vero cells. Thus, this study offered green ZnO NPs that can act as a secure substitute for synthetic antimicrobials and could be applied in numerous biomedical applications.