Kinetics Study On The Interactions Between Functionalized Multi-Walled Carbon Nanotubes And Proteins By Quartz Crystal Microbalance

Nanomaterials have attracted many interests for their unique physicochemical properties,which make them have potential applications in many fields,especially in biomedicine,including diagnostics and therapeutics.Carbon nanotubes(CNT) have been widely studied for their potential applications in biology and medicine. CNT can enter various organs and cellular compartments and bind to protein and DNA molecules when they are injected into organism. These properties offer functionalized nanotubes tremendous opportunities to function as intracellular probes,drug carriers,imaging agents,DNA modulators,and other medical devices on the condition that they are biocompatible.The bioactivity of carbon naonotube is modulated by its surface chemistry,surfactant,and other factors.It is an effective method to obtain nontoxic and biocompatible nanotubes by modifying with small chemical reagents.A clear understanding of how nanotubes interact with proteins is a prerequisite for nanomedicine and nanotoxicity.This thesis monitored the interactions of three functionalized multi-walled carbon nanotubes(MWNT) and five proteins with different physicochemical properties,and focused on the kinetics studies and influence factors of MWNT -protein interactions by quartz crystal microbalance.We aimed to establish a novel method for nanomaterials-biomolecules interactions.First,the kinetics constants between the interactions of carboxylated MWNT(MWNT-COOH) and five proteins were measured.Second,the interactions of MWNT-COOH and protein influenced by electrostaticity and hydrophobicity were monitored.Finally,the binding affinities and binding velocities of the interactions between hemoglobin and three MWNT were measured.The binding between MWNT-COOH and five proteins are irreversible. The MWNT-COOH-protein interactions can be influenced by electrostaticity and hydrophobicity.The sequence of binding affinities and binding velocities between hemoglobin and three MWNT are consistent:MWNT-Tyr＞MWNT-iBA＞MWNT-COOH.CONCLUSIONS:1.The binding between five proteins with different physicochemical properties and MWNT-COOH are irreversible;2.QCM is a potent technique for kinetics constants measurement of MWNT-COOH-protein interactions,including association constant and dissociation constant;3.It is intuitionistic to show the influence on MWNT-protein interactions by electrostaticity and hydrophobicity via QCM.SIGNIFICANCE:It was the first time to study the kinetics and influence factors of MWNT-protein interactions by QCM technique,which can give some theoretic supports to screen the functionalized MWNT specifically bind to proteins.These are useful for MWNT' biotoxicity,drug delivery and biocompatible nanotubes synthesis.Quartz crystal microbalance is a novel method to monitor the kinetics between nanomaterials and biomoleculars.