Preparation And Characterization Of Theranostic Polylevodopa-based Nanoparticles

Photothermal therapy(PTT)has less damage to the body and simple operation procedure with non-invasiveness and high selection,which has gradually developed into a new cancer treatment method in recent years.Magnetic resonance imaging(MRI)has high resolution and is friendly to the body without radiation damage or toxicity,which is a common clinical diagnosis.MRI can observe the physiological structure of the targeted tissue in real time and provide reliable diagnostic data.The MRI-mediated PTT theranostic platform has broad application prospect with the advantages of both photothermal therapy and magnetic resonance diagnosis.However,these platforms often require complex preparation processes,harsh preparation conditions,and usually have low yield and reproducibility,which limiting their clinical translational application.In this paper,two kinds of MRI-guided PTT bifunctional nanoparticles were prepared by "one-pot" method in the protein templates(albumin or silk sericin)through integrating the polymerization of levodopa,the reduction of potassium permanganate and the formation of manganese dioxide nanoparticles,which is the albumin/polylevodopa/manganese dioxide hybrid nanoparticle(BSANP)and silk sericin/polylevodopa/manganese dioxide hybrid nanoparticle(SSNP),respectively.The hydrodynamic diameter of BSANP nanoparticle is 47.08±1.12 nm and its r1 value is up to 41.39 mM-1s-1.In vitro and in vivo imaging experiments show that BSANP has good tumor imaging ability and has strong absorption in the near infrared region so that completely eliminates the tumor by mediating photothermal treatment,indicating that BSANP nanoparticle has good photothermal treatment effect and biological safety.The hydrodynamic diameter of SSNP nanoparticle is 95.77±0.36 nm and its r1 value is as high as 61.94 mM-1s-1.In vitro and in vivo imaging results show that SSNP has better contrast effect.At the same time,SSNP has higher absorption value in the near infrared wavelength range of 650-950 nm,which can be used as the PTT agent for treating tumors.The results of in vivo tumor inhibition experiments show that SSNP can completely remove tumors under laser irradiation as the photothermal treatment reagent without obvious toxicity and side effects and has good biological safety.In a word,the BSANP and SSNP nanoparticle have highly efficient magnetic resonance imaging capability,photothermal therapeutic effect and highly biological safety,facile preparation method and good clinical transformation potential.