Preparation Of Antibiotic Functionalized Nanoparticles And And Their Application In Tumor Cell And Bacterial Killing

Cancer and pathogen infections have always threatened people’s lives and health.Antibiotics,as a traditional antibacterial small molecule,are widely used in the treatment of pathogenic bacterium due to their inherent antibacterial activity.Moreover,some antibiotics themselves possess the ability of identifing specific pathogenic bacterium or photodynamic activity.Therefore,based on the multi-functionality of antibiotic molecules and the relevant properties of nanomaterials,to construct multifunctional nanocomposite and to develop new anti-tumor and anti-bacterial methods are of great significance for the study of biomedicine and human health.In this paper,we combine the photodynamic activity of antibiotics with the low cytotoxicity of DNA to prepare composite nanoparticles and apply them to tumor cells killing;On the other hand,we combine the ability of antibiotic for targeted identification bacteria with the photodynamic activity of chemiluminescence conjugated polymer nanoparticles（CLCPN）to prepare antibiotic modified CLCPN,and to study its application in targeted photodynamic killing of Escherichia coli（E.coli）.The detailed study content is as follows:1.Preparation of Norf functionalized DNA nanoparticles and study on its targeted photodynamic killing of human breast cancer cells（MCF-7）.The folate functionalized DNA was designed and assembled with Norf through Gd³⁺chelation to prepare DNA nanoparticles.The DNA nanoparticles with Norf as photosensitizing agent can bind to MCF-7 surface by folic acid modification and produce reactive oxygen species（ROS）under 405 nm light irradiation,which can achieve the targeted photodynamic killing of MCF-7 cells.The result shows that the prepared nanomaterials can achieve high-efficiency photodynamic killing of tumor cells under certain light and dosage conditions.The method expands the application of classic antibiotic Norf and provides new data for new applications of antitumor research.2.Study on polymyxin B（PMB）functionalized chemiluminescent nanoparticles target photodynamic killing of E.coli.CLCPN with azide group was synthesized by nano reprecipitation method.Then,PMB was modified to the surface of polymer nanoparticles through acylamide reaction and click reaction to construct CLCPN functionalized with PMB.Based on the specific recognition ability of PMB for Gram negative bacteria,the functionalized CLCPN is targeted to bind to the surface of E.coli.With the hemin-catalyzed H₂O₂-Luminol chemiluminescence system,the conjugated polymer PEPV can be excited by chemiluminescence energy transfer reaction.Meanwhile,PEPV transfers the energy to BFTB to generate ROS,which realizes the targeted photodynamic killing of E.coli.This method uses PMB as a targeted molecule to perform chemiluminescence photodynamic therapy without the need of external light source,which provides the possibility for the targeted killing of E.coli by chemiluminescence conjugated polymer nanoparticles.