Original Articles

Investigation of the Antibacterial Effects, Skin Sensitivity, and Irritant Properties of a Lubricating Gel Containing Silver/Zinc Oxide Nanostructure and Lidocaine in an Animal Model

Abstract

Background:   Urinary tract infections (UTIs), predominantly catheter-associated (CAUTIs), cause significant morbidity (~380,000 cases), mortality (~9,000-13,000 deaths), and healthcare costs annually. CAUTIs initiate via bacterial biofilm formation on catheters. Current antimicrobial catheters (e.g., silver ions, antibiotics) face limitations like poor efficacy, resistance, and non-adjustability. Nanostructure coatings offer promise; notably, combining Ag/ZnO nanostructures leverages enhanced biocompatibility and potent antibacterial effects for novel CAUTI prevention strategies.

Methods:   AgNPs were chemically synthesized via silver nitrate reduction (sodium citrate/sodium borohydride); ZnO-NPs were prepared from zinc acetate/sodium hydroxide. A lubricant gel containing 2% lidocaine and Ag/ZnO nanostructures (2:8 v/v ratio) was formulated. Nanostructure characterization included DLS, TEM, and ICP-OES. Antibacterial efficacy was assessed via disk diffusion and microdilution (MIC/MBC) against S. aureus and P. aeruginosa. Biocompatibility was evaluated via rabbit ocular irritability and Guinea Pig Maximization Test (ISO 10993-10).

Results:   DLS/TEM characterization showed AgNPs (24.4 nm, spherical) and ZnO-NPs (52.48 nm, clustered) were mono-disperse (PDI ~1 and 0.667). Zeta potential confirmed stability (Ag: -20.7 mV; ZnO: -0.709 mV). ICP-OES quantified concentrations (Ag: 25 ppm; ZnO: 970 ppm). Antibacterial assays revealed weak AgNP activity (MIC/MBC >12.5 µg/mL for both pathogens) but potent ZnO-NP effects (e.g., S. aureus MIC: 0.406 µg/mL). Ag/ZnO hybrids exhibited enhanced efficacy, especially against S. aureus (MIC: 0.02/3.12 µg/mL). The gel was non-irritating (rabbit ocular test) and non-sensitizing (Guinea Pig Maximization Test).

Conclusion:   The active formulation consisting of mixed silver and zinc oxide nanostructures combined with a medical lubricant containing 4% lidocaine demonstrates effective antibacterial activity against Pseudomonas aeruginosa and Staphylococcus aureus, while exhibiting no irritant or sensitizing properties in laboratory animals.

1. Nandini MS, Madhusudan K. Bacteriological profile of catheter associated urinary tract infection and its antimicrobial susceptibility pattern in a tertiary care hospital. J Pharm Sci Res 2016; 8(4):204.
2. Magill SS, Edwards JR, Bamberg W, et al. Multistate point-prevalence survey of health care–associated infections. New Eng J Med 2014; 370(13):1198-208.
3. Stickler DJ, Zimakoff J. Complications of urinary tract infections associated with devices used for long-term bladder management. J Hos Infect 1994; 28(3):177-94.
4. Dawson KA, Salvati A, Lynch I. Nanoparticles reconstruct lipids. Nat Nanotechnol 2009; 4(2):84-5.
5. Crabtree JH, Burchette RJ, Siddiqi RA, et al. The efficacy of silver-ion implanted catheters in reducing peritoneal dialysis-related infections. Perit Dial Int 2003; 23(4):368-74.
6. Islam F, Shohag S, Uddin MJ, et al. Exploring the journey of zinc oxide nanoparticles (ZnO-NPs) toward biomedical applications. Materials 2022; 15(6):2160.
7. Lu W, Luo H, Wu Y, et al. Preparation and characterization of a metered dose transdermal spray for testosterone. Acta Pharm Sin B 2013; 3(6):392-9.
8. Lethongkam S, Paosen S, Bilhman S, et al. Eucalyptus-mediated synthesized silver nanoparticles-coated urinary catheter inhibits microbial migration and biofilm formation. Nanomaterials 2022; 12(22):4059.
9. Roe D, Karandikar B, Bonn-Savage N, et al. Antimicrobial surface functionalization of plastic catheters by silver nanoparticles. J Antimicrob Chemother 2008; 61(4):869–76.
10. Goda RM, El-Baz AM, Khalaf EM, et al. Combating bacterial biofilm formation in urinary catheter by green silver nanoparticle. Antibiotics 2022; 11(4):495.
11. Li K, Tang H, Peng J, et al. Smart lubricant coating with urease‐responsive antibacterial functions for ureteral stents to inhibit infectious encrustation. Adv Funct Mater 2024; 34(2):2307760.
12. Wu K, Yang Y, Zhang Y, et al. Antimicrobial activity and cytocompatibility of silver nanoparticles coated catheters via a biomimetic surface functionalization strategy. Int J Nanomedicine 2015;7241-52.
IssueVol 13 No 3 (2025) QRcode
SectionOriginal Articles
Keywords
Irritability Silver nanostructures Skin sensitization Urinary infection Zinc oxide nanostructures.
Rights and permissions
Creative Commons License This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License.
How to Cite
1.
Jafari A, Naimi Joubani M, Daeihamed M, Azizzade Dobakhshari M, Rasouli Koohi S. Investigation of the Antibacterial Effects, Skin Sensitivity, and Irritant Properties of a Lubricating Gel Containing Silver/Zinc Oxide Nanostructure and Lidocaine in an Animal Model. J Med Bacteriol. 2025;13(3):91-104.