# Dual Action Nitric Oxide-Releasing Polydimethylsiloxane Sponge: Preventing Infection in Needleless Connectors

## TL;DR

A new sponge releases nitric oxide and alcohol to disinfect medical devices, reducing infection risks without promoting microbial resistance.

## Contribution

A nitric oxide-releasing sponge formulation is developed for disinfecting needleless connectors, combining broad-spectrum antimicrobial action with alcohol.

## Key findings

- The sponge achieved significant log reductions in multiple microbial species after 30 minutes of exposure.
- Higher porosity sponges showed enhanced antimicrobial activity and greater disinfectant absorption.
- The formulation minimizes microbial resistance risks due to nitric oxide's short half-life.

## Abstract

Catheter-related bloodstream infections (CRBSIs) are
a prevalent
concern, often resulting from suboptimal disinfection practices of
needleless connectors. Although alcohol-based disinfectants have demonstrated
efficacy, there is growing concern about developing microbial resistance.
Similar to antibiotics in recent decades, microbes have the potential
to develop resistance to these alcohol-based therapies. Therefore,
this study delves into the antimicrobial potential of nitric oxide
(NO), an endogenous gas molecule with broad-spectrum antimicrobial
properties, in combination with the widely used disinfectant 70% isopropanol
(IPA). Due to its short half-life, NO presents minimal risk of microbial
resistance development. By incorporating S-nitroso-N-acetylpenicillamine (SNAP), a synthetic NO donor, into
hydrophilic-modified polydimethylsiloxane (PDMS-PEO) sponges using
70% IPA, the sponge functions as an antimicrobial reservoir, effectively
sterilizing the hub region of needleless connectors. Formulation-dependent
effects on sponge porosity were observed, affecting compressive strength,
absorption capacity, SNAP retention, and NO release kinetics. Up to
30% variation in sponge porosity coincided with a tunable compressive
modulus, increased absorption capacity of 70% IPA, and enhanced SNAP
loading after 15 min. These properties enable significantly greater
SNAP release within 30 min. Zone of inhibition demonstrated higher
porosity leads to more significant inhibition of Escherichia
coli, Pseudomonas aeruginosa, Staphylococcus aureus, Staphylococcus epidermidis, and Candida
albicans. The disinfection of needleless connectors
demonstrated a 2.91-, 7.04-, 2.02-, 3.21-, and 5.65-log reduction
in E. coli, P. aeruginosa, S. aureus, S. epidermidis, and C. albicans viability after
30 min. These findings highlight the potential of this approach for
efficient microbial decontamination in healthcare settings while offering
adaptability for diverse biomedical applications.