Effect of Nanoparticle Surface Chemistry on Adsorption and Fluid Phase Partitioning in Aqueous/Toluene and Cellular Systems.
Copolymers of di(ethylene glycol) methyl ether methacrylate (x = MeO2MA) and oligo(ethylene glycol) methyl ether methacrylate (y = OEGMA) display lower critical solution phenomena in aqueous systems that are tunable by the copolymer ratio (x:y), ionic strength, and temperature. These properties enable tuning the hydrophobicity of macromolecular systems by variation of (x:y). For nanoparticles stabilized with these macromolecules, this provides a systematic approach to understanding the impact of surface chemistry, specifically hydrophobicity, on the equilibrium and transport properties of nanomaterials in biphasic systems. We synthesized a homologous series of gold nanoparticles capped by these copolymers, Au@(MeO2MA(x)-co-OEGMA(y)). By varying the copolymer 95:5 < (x:y) < 80:20 ratio, we studied the effect of surface hydrophobicity on the nanoparticle equilibrium adsorption isotherm and phase transfer at the aqueous-toluene interface. The increase in hydrophobicity from (x:y) = 80:20 to (x:y) = 95:5 is accompanied by an increase in the fractional coverage of the aqueous-toluene interface from f = 0.3 to f > 1, or multilayer adsorption and an increase in the characteristic adsorption timescale from τ(D) = 31 to τ(D) = 450 seconds. The equilibrium partition coefficient for the aqueous/toluene systems, K(T/W) is also a strong function of (x:y), increasing from K(T/W) (80:20) = 0.7 to K(T/W) (95:5) = 9.8. We also observed an increase in cellular uptake for increasing (x:y) suggesting that surface chemistry alone plays a significant role in intercellular transport processes.
Filippo
F
Gambinossi
Dana
D
Lapides
Chris
C
Anderson
Munish
M
Chanana
James K
JK
Ferri
D000327:Adsorption; D000818:Animals; D002460:Cell Line; D004705:Endocytosis; D006046:Gold / Q000737:chemistry* / Q000493:pharmacokinetics; D057446:Hydrodynamics; D007700:Kinetics; D053768:Metal Nanoparticles / Q000737:chemistry*; D051379:Mice; D011092:Polyethylene Glycols / Q000737:chemistry / Q000493:pharmacokinetics; D013499:Surface Properties; D014050:Toluene / Q000737:chemistry*
D014050:Toluene; D011092:Polyethylene Glycols; D006046:Gold