Water-dispersed antimicrobial microgel with copper(ii) complex for low-cytotoxicity infection control

Overview

This technology offers a new class of water-dispersed antimicrobial microgels designed to reduce or replace conventional quaternary ammonium salt disinfectants. The microgels incorporate an immobilized bimolecular copper(II) complex that delivers rapid bactericidal action against Staphylococcus aureus while maintaining very low cytotoxicity toward human cells. By targeting a minimal inhibitory concentration below 2 µg/mL and preserving over 95% viability in human dermal fibroblasts, the platform addresses two persistent challenges in antimicrobial product development: rising bacterial resistance and the cellular toxicity that limits many existing agents.

The approach is particularly relevant for industries seeking effective, biocompatible antimicrobial solutions for wound care, surface disinfection, personal care products, and medical device coatings where both efficacy and cellular safety are critical.

Technical specifications

Core composition and mechanism:

• Water-dispersed microgel particles with an embedded bimolecular copper(II) complex
• Antimicrobial action is driven by the immobilized metal complex rather than freely diffusible actives, which helps limit off-target cellular exposure
• Designed as a drop-in or partial replacement for quaternary ammonium compound-based formulations

Validated performance characteristics:

• Bactericidal activity observed in less than 5 minutes at 0.78 µg/mL (2× MIC) of immobilized metal complex in microgel dispersion
• Minimal inhibitory concentrations between 0.39 and 4.8 µg/mL across 25 evaluated microgel variants against S. aureus
• Re-plating assays confirm bactericidal behavior after 24 hours of growth
• THP-1 human immune cell viability above 99% after 1-hour exposure at 0.39 µg/mL (1× MIC)

Current development focus:

• Scale-up synthesis to 10 g batches with established core composition
• Replacement of ionic surfactants with nonionic sugar-based surfactants to improve biocompatibility and formulation flexibility
• Structure–activity relationship studies to refine composition for optimal efficacy and safety balance

Technology readiness level

The technology is at an early-to-mid stage of development. Proof-of-concept data has been generated across 25 microgel compositions using broth microdilution, re-plating, and time-kill assays, with parallel cytotoxicity screening on THP-1 cells. Human dermal fibroblast testing is underway to broaden the safety profile. Next steps include scaled synthesis, expanded testing against multiple S. aureus strains, and composition optimization guided by structure–activity relationships. The technology is not yet commercially deployed but is positioned for collaborative development toward formulation integration and regulatory-relevant validation.