Synthesis Of PH-responsive Polymer And Their Application In Isolation Of Exosomes

Exosomes are a class of microvesicles that can be secreted by most of the cells.Exosomes carry a large amount of information such as nucleic acids and proteins and are related to a variety of physiological and pathological functions.Thus,exosomes are of important values in disease diagnosis and treatment.The development of novel kind of isolation materials for exosomes are vitally important for studying exosomes and their biomedical functions.In the present work,a novel pH response polymer material was fabricated via free radical polymerization and its separation and enrichment performances for exosomes were further studied.The full text is divided into four chapters.The first chapter is divided into four parts.The first part is an overview of exosomes.The second part is a brief introduction of the recent advancements of the separation methods for exosomes.The third part briefly describes the research progress of pH responsive polymer.In the last part,we briefly describe the contents of this work.In the second chapter,acrylamide azobenzene(AAAB)was firstly synthesized via the reaction of p-aminoazobenzene and acryloyl chloride.Secondly,with AAAB and dimethylaminoethyl methacrylate(DMAEMA)as the monomers,a new pH responsive polymer material was facilely fabricated under the initiation of azobisisobutyronitrile(AIBN).The characterization results of Fourier transform infrared spectrometer,mass spectrometry,and nuclear magnetic resonance spectroscopy prove that the pH responsive polymer was successfully synthesized.The UV turbidity test shows that the pH responsive polymer is of sensitive pH response characteristics.The ΔpH value of the dissolution-precipitation response is around 1 pH unit and the precipitation rate is above 95% when pH was shifted from 6.5 to 7.5.Furthermore,the pH response polymer is of good cycle stability.The non-specific adsorption characteristic of the pH response polymer was investigated with bovine serum albumin(BSA)solution.The non-specific adsorption of the material can be basically eliminated after washing with PBS solution.The low non-specific adsorption characteristic could reduce the interference of the heteroproteins when it is used for separation of exosomes.In the third chapter,the pH response polymer was further applied to the isolation of exosomes in the culture medium of breast cancer cell line MCF-7.The signal proteins of exosome were further identified by Western Blot.The results demonstrate that the content of the signal proteins of exosomes was significantly increased after isolation via pH response polymer.The recycle rate of the method was further calculated via nanoparticle tracer analysis(NTA).The recycle rate is up to 87%.Finally,the pH response polymer was further used for the separation of exosomes in human serum.The results of Western Blot show that the serum exosomes can also be efficiently isolated.Finally,the full text is summarized.In this work,a pH responsive polymer with good pH-response properties,good cycle stability and low non-specific adsorption characteristic was developed.The new pH response polymer was successfully applied for separation of exosomes in cell culture medium and human serum which indicating a good potential in exosomes enrichment and isolation.