The effect of TAT conjugated platinum nanoparticles on lifespan in a nematode Caenorhabditis elegans model.

We have shown that platinum nanoparticle species (nano-Pt) is a superoxide dismutase/catalase mimetic that scavenges superoxide and hydrogen peroxide. In Caenorhabditis elegans, nano-Pt functions as an effective antioxidant that induces an extension in lifespan and strong resistance against excessive oxidative stress. Our study with C. elegans was the first trial to use nano-Pt as a bio-active substance. However, a high concentration of nano-Pt was required for these survival effects, probably due to limited membrane permeability. Here, we show that the conjugation of nano-Pt with an HIV-1 TAT fusion protein C-terminally linked to a peptide with high affinity for platinum improves internalization, eliciting a similar level of antioxidant effects at one hundredth the concentration of unconjugated nano-Pt. This approach is a potential method to facilitate translocation of bio-active nanoparticles into living organisms and could be a model assay for estimate the effects of antioxidant in living organism. Copyright 2010 Elsevier Ltd. All rights reserved.