Synthesis Of Polydopamine-Based Nanoparticles And Their Tumor Photothermal/Chemical Therapy Research

The development of modern medicine has brought new opportunities for the diagnosis and treatment of tumors.Many new cancer treatment methods show great potential for application,such as hyperthermia,chemotherapy,photodynamic therapy,gene therapy,etc.They have attracted attention due to their advantages such as high efficiency,minimal invasiveness,and low toxic and side effects.At present,the single-method tumor therapy system has great limitations in terms of efficacy.Therefore,the development of a tumor treatment system with multi-modality combined therapy is a trend in the future development of cancer therapy.Polydopamine has good adhesion,biocompatibility and high efficiency of photothermal conversion,providing an excellent platform for the construction of multifunctional tumor treatment system.In recent years,polydopamine has been widely used in photothermal therapy,drug transportation and other fields,and is an excellent biological material suitable for constructing multifunctional tumor treatment systems.In this paper,polydopamine nanoparticles were used as the core to construct two kinds of polydopamine composite nanoparticles with pH-sensitive and tumor cell targeting for the combination of thermotherapy and chemotherapy.One is a polydopamine composite nanoparticle（PDA@（PDDA-ADA）₃@PEI-FA）modified by layer self-assembly of poly（diallyldimethylammonium chloride）and a partially oxidized sodium alginate polyelectrolyte layer.The other is polydopamine composite nanoparticles（PDA@（PEI-ADA）₃@PEI-FA）modified with polyethylenimine and a partially oxidized sodium alginate polyelectrolyte layer.Among them,the polyelectrolyte layer is loaded with the anticancer drug doxorubicin via a pH-responsive Schiff base bond,and its surface-modified folate molecules can enhance the targeting of the polydopamine composite nanoparticles.In this paper,we studied the physicochemical properties of two kinds of polydopamine composite nanoparticles,and proved that the two kinds of polydopamine composite nanoparticles have excellent photothermal properties and pH response drug release properties.Two different drug-loaded polyelectrolyte layers were studied by a dissipative quartz crystal microbalance.The reasons for the differences in the properties of the two drug-carrying polyelectrolyte layers were analyzed,and two drug-loaded polyelectrolyte layer models were constructed.It was concluded that PDA@（PDDA-ADA）₃@PEI-FA has a structurally porous soft drug-loaded polyelectrolyte layer with a drug loading of 6.10%±1.3%,which is a composite polydopamine nanoparticles with higher drug loading performance.Based on the above results,the PDA@（PDDA-ADA）₃@PEI-FA particles with better drug-loading properties were used as models to study the cytotoxicity of cervical cancer cells in vitro.The data showed that the photothermal therapy and chemotherapeutic effects of PDA@（PDDA-ADA）₃@PEI-FA were very significant,and the hyperthermia-chemotherapy combination therapy was superior to a single hyperthermia or chemotherapy treatment effect,up to 92%of the cells.The killing rate,and its own good biocompatibility,is an excellent hyperthermia-chemotherapy combination therapy system.