Investigations on the interactions of proteins with polyampholyte-coated magnetite nanoparticles.
Magnetite nanoparticles have been widely used in biomedical applications, especially as contrast agents in magnetic resonance imaging. In this work, the antifouling property of polyampholyte-coating (poly(acrylic acid) (PAA)-co-3-(diethylamino)-propylamine (DEAPA)) is systematically demonstrated. Polyampholyte-coated magnetite nanoparticles (NP1) and PAA-coated magnetite nanoparticles (NP2) were synthesized to investigate their interactions with BSA and lysozyme (LYZ) by high-resolution turbidimetric titration, dynamic light scattering (DLS), and isothermal titration calorimetry (ITC) in phosphate buffer saline (PBS) buffer with pH 7.4. The abundant carboxyl groups of NP2 and polyampholyte coating of NP1 were well proven by TGA, ζ-potential, and titration methods. Turbidity change shows that NP1 have no interaction with both proteins other than NP2 having adsorption with LYZ, which was further confirmed by DLS. Besides, ITC gives the exact enthalpy change and unveils the binding stoichiometry for each interaction. All characterizations demonstrate the antifouling property of NP1 to both negatively charged protein BSA and positively charged protein LYZ. The polyampholyte-coated magnetite nanoparticles were shown to be a promising material to eliminate the strong interaction with proteins in complex medium, for example, when it is applied for MRA contrast agents with long in vivo circulation time.
Shanghai Engineering Research Center of Medical Device and Technology at Med-X, School of Biomedical Engineering, Shanghai Jiao Tong University , Shanghai 200030, P. R. China.
Tao
T
Zhao
Kaimin
K
Chen
Hongchen
H
Gu
D000180:Acrylic Resins / Q000737:chemistry; D000327:Adsorption; D002151:Calorimetry; D003287:Contrast Media / Q000737:chemistry / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008027:Light; D058185:Magnetite Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D009113:Muramidase / Q000737:chemistry* / Q000378:metabolism; D009391:Nephelometry and Turbidimetry; D011108:Polymers / Q000737:chemistry*; D012542:Scattering, Radiation; D012710:Serum Albumin, Bovine / Q000737:chemistry* / Q000378:metabolism; D013499:Surface Properties; D013816:Thermodynamics
D000180:Acrylic Resins; D003287:Contrast Media; D058185:Magnetite Nanoparticles; D011108:Polymers; D012710:Serum Albumin, Bovine; C006903:carbopol 940; D009113:Muramidase