In Situ Polymerization Induced Aggregation Of Gold Nanoparticles For Imaging Guided Postoperative Treatment

The construction of novel diagnostic and collaborative treatment nanomaterials has become the point and frontier of the current interdisciplinary fields such as chemistry and materials science.Traditional nanomaterials lack microenvironmental responsiveness,and it is difficult to achieve good diagnosis and treatment capabilities in organisms,which limits their application in organisms.In traditional light diagnosis and treatment,because the tissue absorbs the laser light,the penetration ability of the laser light to tissues of different depths is different and the tumor is not isotropic.As a result,light therapy cannot completely kill cancer cells.Surgical treatment,as a commonly used clinical tumor treatment method,can effectively remove tumors and marginal tissues.Therefore,the two can be effectively combined to thoroughly and effectively treat cancer through synergistic treatment.Biomacromolecules such as polysaccharides,proteins and nucleic acids in organisms are all generated in cells through biocatalytic polymerization reactions,and biomacromolecules play an important role in life activities.More importantly,the artificial free radical polymerization in a biological environment is rarely reported,and the construction of a polymer with biological functions through free radical polymerization in a biological environment is of great significance for biomedical applications.In this article,we use radical polymerizable monomers to modify gold nanoparticles.In summary,this article constructed an in-situ polymerization-induced aggregation of gold nanoparticles based on the modified functional strategy and studied its application in photoacoustic imaging-mediated photothermal postoperative treatment.The main contents of this article are as follows:Chapter 1: This chapter mainly introduces the definition,classification,research status and scientific problems that need to be solved for photothermal therapy,photoacoustic imaging,gold nanomaterials,and polymerization in biological environments,as well as a review of previous studies.Chapter 2: In this chapter,by using N-acryloylcysteine to replace the citrate ligand on the surface of gold nanoparticles(Au NPs),N-acryloylcysteine that can be polymerized to induce aggregation is obtained Acid-modified gold nanoparticles(NAC-Au NPs),first use horseradish peroxidase to catalyze hydrogen peroxide under test tube conditions,and the resulting hydroxyl radicals cause NAC-Au NPs to undergo free radical polymerization induced aggregation to obtain N-Acrylic cysteine modified gold nano-aggregates(PNAC-Au NPs),the chemical structure of the materials before and after polymerization were studied by using the test methods of carbon nuclear magnetic resonance,absorption spectroscopy,transmission electron microscopy,dynamic light scattering and Zeta potential.,Morphology,particle size,near-infrared absorption,changes in Zeta potential.The successful polymerization in the presence of hydroxyl radicals was proved by carbon nuclear magnetic resonance spectroscopy and infrared spectroscopy.Finally,the photothermal conversion and photoacoustic imaging capabilities of the material were tested.PNAC-Au NPs showed good photothermal conversion capabilities and good photoacoustic imaging capabilities.Based on these characteristics,we proved that NAC-Au NPs showed good photoacoustic imaging-mediated photothermal therapy and photodiagnosis and treatment potential in vitro.Chapter 3: The rich hydrogen peroxide in the tumor microenvironment provides a good external condition for the polymerization and induction of NAC-Au NPs in the tumor microenvironment.Cell experiments in vitro proved that NAC-Au NPs can polymerize in cells in the presence of horseradish peroxidase and hydrogen peroxide to obtain PNAC-Au NPs.Transmission electron microscopy of biological samples further proves that NAC-Au The aggregation of NPs in the biological environment,and PNAC-Au NPs can significantly increase the photothermal temperature and kill tumor cells under the irradiation of 808 nm laser.PNACAu NPs undergoes photoacoustic imaging with thermal vibration due to the photothermal heating effect under laser irradiation,and performs photoacoustic imaging-mediated postoperative photothermal treatment through photoacoustic imaging combined with surgical treatment and postoperative phototherapy.Good killing of tumor tissue ensures that it does not recur and minimizes damage to surrounding normal tissue cells.The above research results show that the NAC-Au NPs constructed in this paper can be used for photoacoustic imaging-mediated postoperative photothermal treatment of tumor tissues.