Application Of Magnetic Nanoparticles To The Study Of Interaction Between Fluorescent Drugs With Bovine Serum Albumin

Recently,magnetic nanoparticles attract the researchers attention,owing to their double characteristics of magnetic materials and nano-materials.The controlled synthesis of magnetic nanoparticles with narrow size distribution,aqueous stability and high magnetic response is of primary importance for many applications.Functional magnetic nanoparticles have less aggregation and better biological compatibility.The practical applications were greatly improved.The interaction between drugs and BSA has been an intensively research of biological and chemistry.The efficiency of treatment of disease is directly affected by the combining location and functionary mechanism of drugs in body.The experiment results could provide useful technical support for appropriately understanding the toxicity of drug,design and development of new drugs.This paper adopts magnetic nanoparticles to separate the target molecules?BSA and fluorescent drugs?.BSA was immobilized on the surface of magnetic nanoparticles.Fluorescent drugs were added into this system to react with BSA.Fluorescence analysis with high sensitivity was used to obtain the binding information of fluorescent drugs and BSA.The paper was divided into three chapters:Chapter 1: Magnetic nanoparticles and proteins were briefly introduced.The research methods for studying the mechanisms of the drugs and protein,and some information about the application of functionalized Fe₃O₄ magnetic nanoparticles in binding process was reviewed.Chapter 2: A novel method was developed for studying the interaction between epirubicin hydrochloride?EPI?and bovine serum albumin?BSA?by fluorescence spectrometry.Fe₃O₄ magnetic nanoparticles synthesized and functionalized with thiol group were employed for the immobilization and separation of target BSA in reaction solutions.The concentrations of the unimmobilized BSA and unbinding EPI were obtained separately by fluorescence spectrometry.The binding constants?Ka?and number of binding sites?n?of EPI with BSA were calculated.In this study,the Ka value was 5.05 × 105 L mol^-1 and the n value was 1.15,suggesting a strong binding of EPI to BSA.The effects of common metal ions on Ka of EPI with BSA were also investigated,and the results showed there were obvious bindings between the metal ions with BSA.The precise binding sites of EPI on BSA were determined as site I from the competitive displacement experiments.Chapter 3: An improved method was put forward in this section.It was used to investigate the interaction between salidroside?SAL?and bovine serum albumin?BSA?.Amino-functionalized magnetic nanoparticles were successfully synthesized.With glutaraldehyde as the coupling agent,BSA was immobilized onto the amino-functionalized magnetic nanoparticles.The fluorescence of free BSA was examined to calculate the amount of immobilized BSA.Then,SAL was added to bind with BSA.The fluorescence of free SAL was examined to calculate the amount of bound SAL.Finally,the obtained Ka and n were 4.033 × 105 L mol^-1 and 0.83 by using the Scatchard equation,respectively.In addition,the effects of common metal ions on the binding constants of SAL-BSA system and binding site of SAL on BSA were also investigated.