# A Carboxyl-Functionalized Graphene Quantum Dot Coating for Catheters Effective Against Emerging Drug-Resistant Candidozyma auris

## TL;DR

A new graphene quantum dot coating effectively kills drug-resistant Candidozyma auris fungi, which can cause dangerous catheter-related infections.

## Contribution

A carboxyl-functionalized graphene quantum dot coating is introduced as a potent antifungal treatment for drug-resistant Candidozyma auris.

## Key findings

- Photoactivated cGQDs killed 99.9% of C. auris and C. albicans fungi in 30 minutes.
- cGQD coatings on catheters showed strong fungicidal activity against drug-resistant strains.
- cGQDs are effective against multiple clades of C. auris and resistant Candida strains.

## Abstract

Candidozyma auris is an emerging opportunistic fungal pathogen that can cause serious catheter-related blood stream infections associated with high morbidity and mortality. The traditional antifungal treatment with polyenes, azoles or echinocandins is becoming less effective due to both intrinsic and developed resistance, complicating treatment. This study demonstrates the potent fungicidal activity of carboxyl-functionalized graphene quantum dots (cGQDs) against a panel of C. auris strains, spanning clades I to V, and a Candida albicans reference strain. Photoactivation of cGQDs in suspension with 435 nm blue light killed 99.9% of the fungi within 30 min even though the majority of test strains were resistant to at least one conventional antifungal. Moreover, cGQDs coated on flexible polydimethylsiloxane surfaces and commercial catheters via electrostatic layer-by-layer deposition with alternating positively charged polydiallyldimethylammonium polymer showed strong fungicidal activity against C. auris and C. albicans. These findings show that the cGQDs, both in suspension and in a thin film coating, have potential for future clinical development. In particular, their application to catheters may help prevent Candidozyma and Candida catheter-related infections.