Gold nanoparticles for tracking bacteria clearance by regulated irrigation and negative pressure-assisted wound therapy.

Aim: Regulated negative pressure-assisted wound therapy is a fundamental, nonpharmaceutical technology for acute and chronically infected wounds, yet bacterial clearance and biofilm buildup remain a challenge for healing. Regulated irrigation combined with negative pressure (RI-NPT) is emerging as an alternative therapeutic strategy for reducing bacterial load. Here, we analyzed RI-NPT hydrokinetics and efficacy of bacterial load reduction in wounds. Materials & methods: Escherichia coli were loaded with gold nanoparticles, quantified by flame atomic absorption spectroscopy. Computed tomography (CT) imaging tracked bacterial distribution over time in a low-flow rat wound model. Bacterial load was quantified using a novel CT ruler. Result: Flame atomic absorption spectroscopy showed loading of 1.7 x 10(3) +/- 0.2 gold nanoparticles/cell. CT tracking revealed that while regulated negative pressure-assisted wound therapy reduced bacterial load to a limited extent (5%), RI-NPT significantly increased bacterial outflow and clearance (by 45%). Conclusion: This nanotechnology-based approach demonstrates that RI-NPT is essential for reducing bacterial load and, thus, for promoting wound healing. [GRAPHICS] .