Zhou J Deng

Publications (2)33.03 Total impact

• Article: Plasma protein binding of positively and negatively charged polymer-coated gold nanoparticles elicits different biological responses.

  Zhou J Deng, Mingtao Liang, Istvan Toth, Michael Monteiro, Rodney F Minchin
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  ABSTRACT: Abstract The binding of proteins to nanoparticles is an important event that can determine the biological effect of nanoparticles in the body. We examined plasma protein binding to gold nanoparticles (5-20 nm) with different surface charge. Positively and negatively charged nanoparticles bound a range of proteins whereas neutral nanoparticle bound very little. As little as 25% neutral polymer on the surface of the charged nanoparticles inhibited protein binding, with only slight change in surface charge. Fibrinogen bound with high affinity to both of the charged nanoparticles. However, binding kinetics and protease digestion suggested that the binding orientation for each nanoparticle was different. Only the negatively charged nanoparticles induced cytokine release from THP-1 cells. While common proteins can bind to different nanoparticles, the biological outcome may not be the same. Consequently, knowledge about the composition of the protein corona is not sufficient to predict biological effects of nanoparticles.
  Nanotoxicology 03/2012; · 5.76 Impact Factor
• Source

  Available from: Istvan Toth

  Article: Nanoparticle-induced unfolding of fibrinogen promotes Mac-1 receptor activation and inflammation.

  Zhou J Deng, Mingtao Liang, Michael Monteiro, Istvan Toth, Rodney F Minchin
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  ABSTRACT: The chemical composition, size, shape and surface characteristics of nanoparticles affect the way proteins bind to these particles, and this in turn influences the way in which nanoparticles interact with cells and tissues. Nanomaterials bound with proteins can result in physiological and pathological changes, including macrophage uptake, blood coagulation, protein aggregation and complement activation, but the mechanisms that lead to these changes remain poorly understood. Here, we show that negatively charged poly(acrylic acid)-conjugated gold nanoparticles bind to and induce unfolding of fibrinogen, which promotes interaction with the integrin receptor, Mac-1. Activation of this receptor increases the NF-κB signalling pathway, resulting in the release of inflammatory cytokines. However, not all nanoparticles that bind to fibrinogen demonstrated this effect. Our results show that the binding of certain nanoparticles to fibrinogen in plasma offers an alternative mechanism to the more commonly described role of oxidative stress in the inflammatory response to nanomaterials.
  Nature Nanotechnology 01/2011; 6(1):39-44. · 27.27 Impact Factor