Ultrasonic-assisted synthesis of lignin-capped Cu2O nanocomposite with antibiofilm properties

• Published in: Ultrasonics sonochemistry Vol. 92; p. 106241
• Main Authors: Maruthapandi, Moorthy, Gupta, Akanksha, Saravanan, Arumugam, Jacobi, Gila, Banin, Ehud, Luong, John H.T., Gedanken, Aharon
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.01.2023; Elsevier
• Subjects: Antibiofilm; Antimicrobial; Cytotoxicity; Lignin Cu2O nanocomposite; Original; Ultrasonic method; Antimicrobial; Lignin Cu2O nanocomposite; Cytotoxicity; Antibiofilm; Ultrasonic method
• DOI: 10.1016/j.ultsonch.2022.106241
• ISSN: 1350-4177

[Display omitted] •The lignin capped Cu2O was prepared by a green ultra-sonochemical approach.•The lignin capped Cu2O nanocomposite material is stabilized due to the formation of strong interaction between the lignin chain and the Cu2O.•The lignin nanocomposite provides an efficient antibiofilm properties against the sensitive and resistant bacteria.•A postulated mechanism is provided to highlight the role of the L-Cu nanocomposite, which efficiently penetrates bacterial cells and interferes with biofilm formation. Under ultrasonication, cuprous oxide (Cu2O) microparticles (<5 µm) were fragmented into nanoparticles (NPs, ranging from 10 to 30 nm in diameter), and interacted strongly with alkali lignin (Mw = 10 kDa) to form a nanocomposite. The ultrasonic wave generates strong binding interaction between lignin and Cu2O. The L-Cu nanocomposite exhibited synergistic effects with enhanced antibiofilm activities against E. coli, multidrug-resistant (MDR) E. coli, S. aureus (SA), methicillin-resistant SA, and P. aeruginosa (PA). The lignin-Cu2O (L-Cu) nanocomposite also imparted notable eradication of such bacterial biofilms. Experimental evidence unraveled the destruction of bacterial cell walls by L-Cu, which interacted strongly with the bacterial membrane. After exposure to L-Cu, the bacterial cells lost the integrated structural morphology. The estimated MIC for biofilm inhibition for the five tested pathogens was 1 mg/mL L-Cu (92 % lignin and 8 % Cu2ONPs, w/w %). The MIC for bacterial eradication was noticeably lower; 0.3 mg/mL (87 % lignin + 13 % Cu2ONPs, w/w %) for PA and SA, whereas this value was appreciably higher for MDR E. coli (0.56 mg/mL, 86 % lignin and 14 % Cu2O NPs). Such results highlighted the potential of L-Cu as an alternative to neutralize MDR pathogens.