Enhanced bactericidal, antibiofilm and antioxidative response of Lawsonia inermis leaf extract synthesized ZnO NPs loaded with commercial antibiotic

Balasubramanian Malaikozhundan; Sonaimuthu Mohandoss; Raman Krishnamoorthi; Palanichamy Vidhya Bharathi; Subramanian Palanisamy; Jayaraj Vinodhini

doi:10.1007/s00449-024-03000-9

Enhanced bactericidal, antibiofilm and antioxidative response of Lawsonia inermis leaf extract synthesized ZnO NPs loaded with commercial antibiotic

Bioprocess Biosyst Eng. 2024 Apr 12. doi: 10.1007/s00449-024-03000-9. Online ahead of print.

Authors

Balasubramanian Malaikozhundan^#¹, Sonaimuthu Mohandoss^#², Raman Krishnamoorthi^{3

4}, Palanichamy Vidhya Bharathi³, Subramanian Palanisamy⁵, Jayaraj Vinodhini^{6

7}

Affiliations

¹ Department of Biology, The Gandhigram Rural Institute (Deemed to Be University), 624 302, Gandhigram, Dindigul District, Tamil Nadu, India. kozhundan.malai@gmail.com.
² School of Chemical Engineering, Yeungnam University, 38541, Gyeongsan, Republic of Korea.
³ Department of Biology, The Gandhigram Rural Institute (Deemed to Be University), 624 302, Gandhigram, Dindigul District, Tamil Nadu, India.
⁴ Pharmaceutics Laboratory, Graduate Institute of Natural Products, Chang Gung University, 333, Taoyuan, Taiwan.
⁵ East Coast Life Sciences Institute, Gangneung-Wonju National University, 120, Gangneung, 210-702, Gangwon, Republic of Korea.
⁶ Department of Biotechnology, Dr. Umayal Ramanathan College for Women, Alagappa University, 630 003, Karaikudi, Tamil Nadu, India.
⁷ Parvathy's Anugrahaa International School, 624 002, Dindigul, Tamil Nadu, India.

^# Contributed equally.

PMID: 38607416
DOI: 10.1007/s00449-024-03000-9

Abstract

Globally, antibiotic resistance is a challenging issue in healthcare sector. The emergence of multiple drug-resistant bacteria has forced us to modify existing medicines and or formulate newer medicines that are effective and inexpensive. In this perspective, this study involves the formation of zinc oxide nanoparticles (ZnO NPs) by utilizing the Lawsonia inermis (Li) leaf extract. The prepared L. inermis leaf extract mediated ZnO NPs (Li-ZnO NPs) were bio-physically characterized. The antibacterial and radical scavenging effects of Li-ZnO NPs were evaluated. In addition, ZnO NPs were conjugated with standard antibiotic (ciprofloxacin) and its drug loading efficiency, drug release and antibacterial efficacy were tested and compared with non-drug loaded ZnO NPs. An absorbance peak at 340 nm was noted for Li-ZnO NPs. After conjugation with the drug, two absorbance peaks- one at 242 nm characteristic of ciprofloxacin and the other at 350 nm characteristics of ZnO NPs were observed. The crystallite size was 18.7 nm as determined by XRD. The antibacterial effect was higher on Gram-positive (S. aureus and S. pyogenes) than the Gram-negative pathogens (E. coli and K. pneumoniae). Inhibition of S. aureus and S. pyogenes biofilm at 100 μg mL^-1were, respectively, 97.5 and 92.6%. H₂O₂ free radicals was inhibited to 90% compared to the standard ascorbic acid at 100 μg mL^-1. After drug loading, the FTIR spectrum confirmed the existence of ciprofloxacin peaks at 965 cm^-1 and Zn-O bond at 492 cm^-1. The drug loading capacity of 15 nm sized ZnO NPs was higher (58, 75, 90 and 95% at 1, 2.5, 5 and 10% drug concentrations, respectively) compared to 20 nm. Similarly, the percentage of drug (ciprofloxacin) released from 15 nm ZnO NPs were increased to 90% at 10% drug-loaded samples, respectively. Also, the antibiotic loaded ZnO NPs had significant antibacterial effects against tested bacteria compared to Li-ZnO NPs and ciprofloxacin alone. This revealed that the antibiotic loaded ZnO NPs offer a sustainable route to treat multi-drug-resistant bacterial infections.

Keywords: Antibiotic; Drug release; Dwarf shrub; MDR; Nanomedicine.