Interaction of gold nanoparticles with common human blood proteins.
In order to better understand the physical basis of the biological activity of nanoparticles (NPs) in nanomedicine applications and under conditions of environmental exposure, we performed an array of photophysical measurements to quantify the interaction of model gold NPs having a wide range of NP diameters with common blood proteins. In particular, absorbance, fluorescence quenching, circular dichroism, dynamic light scattering, and electron microscopy measurements were performed on surface-functionalized water-soluble gold NPs having a diameter range from 5 to 100 nm in the presence of common human blood proteins: albumin, fibrinogen, gamma-globulin, histone, and insulin. We find that the gold NPs strongly associate with these essential blood proteins where the binding constant, K, as well as the degree of cooperativity of particle--protein binding (Hill constant, n), depends on particle size and the native protein structure. We also find tentative evidence that the model proteins undergo conformational change upon association with the NPs and that the thickness of the adsorbed protein layer (bare NP diameter <50 nm) progressively increases with NP size, effects that have potential general importance for understanding NP aggregation in biological media and the interaction of NP with biological materials broadly.
Lacerda
Silvia H De Paoli
SH
Center for Biological Evaluation and Research, Food and Drug Administration, Bethesda, Maryland 20892, USA. silvia.lacerda@fda.hhs.gov
Park
Jung Jin
JJ
Meuse
Curt
C
Pristinski
Denis
D
Becker
Matthew L
ML
Karim
Alamgir
A
Douglas
Jack F
JF
D000818:Animals; D001798:Blood Proteins / Q000378:metabolism*; D002417:Cattle; D002942:Circular Dichroism; D006046:Gold / Q000737:chemistry* / Q000378:metabolism*; D006801:Humans; D008027:Light; D053768:Metal Nanoparticles / Q000737:chemistry*; D008854:Microscopy, Electron; D010316:Particle Size; D011485:Protein Binding; D012542:Scattering, Radiation; D013050:Spectrometry, Fluorescence
D001798:Blood Proteins; D006046:Gold