Gold nanoparticle modifies nitric oxide release and vasodilation in rat aorta

Area of Science:

• Biomedical Engineering
• Nanotechnology
• Pharmacology

Background:

• Nitric oxide (NO) is crucial for various biological functions.
• Controlling NO release from NO donors is a significant challenge.
• Gold nanoparticles (AuNPs) offer a platform for modifying drug delivery profiles.

Purpose of the Study:

• To investigate the effect of coupling a ruthenium-based NO donor to AuNPs on NO release kinetics and vasodilation.
• To elucidate the mechanisms underlying vasodilation induced by the AuNPs-NO donor complex.
• To explore the potential of this strategy for controlled NO delivery and targeted biological activation.

Main Methods:

• Synthesis of AuNPs and their subsequent coupling with the NO donor Cis-[Ru(bpy)2(NO)(4PySH)](PF6)3 to form AuNPs-{Ru-4PySH}n clusters.
• Evaluation of vasodilation effects in vitro, assessing maximum effect (ME) and potency (pD2).
• Pharmacological characterization using inhibitors of soluble guanylyl cyclase (sGC) and potassium (K+) channels (TEA).

Main Results:

• AuNPs coupling did not alter the maximum effect (ME) and potency (pD2) of the NO donor in vasodilation.
• The AuNPs-{Ru-4PySH}n cluster exhibited a lower overall NO release compared to the free ruthenium complex, with sustained release in the extracellular medium.
• Ru-4PySH-induced vasodilation was mediated by both sGC and K+ channels, whereas AuNPs-{Ru-4PySH}n primarily activated sGC.

Conclusions:

• AuNPs can reduce the permeability and modulate the release profile of NO donors.
• The AuNPs-{Ru-4PySH}n cluster maintains vasodilator efficacy while altering NO release kinetics and mechanism.
• This approach represents a novel pharmacological strategy for controlled NO delivery to selectively activate biological targets.