Ligand-Doped Copper Oxo-hydroxide Nanoparticles are Effective Antimicrobials

Area of Science:

• Nanotechnology
• Materials Science
• Antimicrobial Agents

Background:

• Increasing bacterial resistance to antimicrobial therapies poses a significant clinical challenge for both systemic and topical treatments.
• Copper ions show promise as inexpensive topical antimicrobials due to their multi-pathway action, which can limit resistance development.
• Existing copper formulations face challenges in releasing ions effectively at biologically compatible pH levels for topical applications.

Purpose of the Study:

• To develop a novel nanoparticulate copper formulation, copper hydroxide adipate tartrate (CHAT), for effective antimicrobial copper ion release in infected wounds.
• To evaluate the efficacy and release characteristics of CHAT compared to copper chloride in topical formulations.

Main Methods:

• Synthesis and characterization of nanoparticulate CHAT, including particle size and zeta potential measurements.
• In vitro antimicrobial efficacy testing against Escherichia coli and Staphylococcus aureus using CHAT and copper chloride.
• Assessment of copper ion release profiles from CHAT formulated in a hydroxyethyl cellulose matrix compared to copper chloride.

Main Results:

• Synthesized CHAT exhibited dispersed aquated particle sizes of 2-5 nm and a zeta potential of -40 mV.
• CHAT demonstrated dose-dependent antimicrobial activity against E. coli and S. aureus, comparable to copper chloride in liquid media.
• In a topical hydroxyethyl cellulose matrix, CHAT provided sustained release of copper ions in the bactericidal range, whereas copper chloride precipitated and showed minimal release.

Conclusions:

• Nanoparticulate CHAT offers a viable solution for topical copper-based antimicrobial therapy, enabling effective copper ion release in a wound environment.
• CHAT overcomes the formulation and release limitations of traditional copper salts, presenting a practical approach to combatting topical bacterial infections.
• Further in vivo studies are warranted to fully explore the therapeutic potential of CHAT for wound infections.