Plasmonic gold nanoparticles possess the ability to open XXXX channels in rat thoracic aorta smooth muscles in a remote control manner.

@entity3529 @entity3079 @entity9476 @entity39271 @entity972 @entity1063
UNASSIGNED: @entity3079 (AuNPs) of ~5nm core size and Zeta-potential of -35mV, having absorption maximum and plasmon resonance in the range of 510-570nm, were studied as a potential @entity3529 -channel opener in vascular smooth muscle (SM) cells. Experimental design of the study comprised SM contractile recordings. When externally applied to the organ bath, AuNPs (10(-6)-3*10(-4)M) led to decrease in amplitude of @entity1063 -induced contractions in a concentration-dependent and endothelium-independent manner in SM thoracic aorta, with mean value of pD2 (-log EC50) 4.2  0.03, Emax=55  4%. Being added to the bath solution in concentration of 10(-4)M, AuNPs significantly increased whole cell peak outward current at +70mV from 32  2pA/pF to 59  5pA/pF (n=14, P<0.05). External irradiation using a 5mW/532nm green laser, to facilitate plasmon resonance, led to an increment in the AuNPs-induced macroscopic outward @entity972 current (IK) from 59  5pA/pF to 74  1pA/pF (n=10, P<0.05). @entity39271 (500nM), when added to the external bathing solution, significantly decreased AuNPs-induced increment of IK in SM cells. Single channel recordings provided a direct confirmation of @entity9476 activation by AuNPs at the single-channel level. Application of AuNPs to the bath potentiated @entity9476 activity with a delay of 1-2min, as was seen initially by more frequent channel openings followed by the progressive appearance of additional open levels corresponding to multiple openings of channels with identical single-channel amplitudes. Eventually, after 10-15min in the presence of AuNPs and especially when combined with the green laser illumination, there was a massive increase in channel activity with >10 channels evident. When irradiated by laser, AuNPs significantly increased the amplitude of maximal AuNPs-induced relaxation from 55  5% to 85  5% (n=10, P<0.05) while the sensitivity of SM to AuNPs was without changes. In summary, plasmonic AuNPs possess the ability to activate @entity9476 channel opening in vascular SM. Laser irradiation facilitates this effect due to local plasmon resonance that, in turn, further increases @entity9476 channel activity causing SM relaxation.
