Synthesis Of High Water-soluble Theranostic Nanomaterials For Optical Imaging & Photothermal Therapy

Photothermal therapy as a new technology of the greastest concern,has been widely applied in solid tumor ablation for its intrinsic advantages of non-invasive,low systemic toxicity,high efficiency and easy to control.However,current available materials can not achieve the best effect due to the low water solubility,active-target and photothermal conversion efficiency.In addition,most reported water-soluble organic photothermal nanoagents are self-assembled from a hydrophobic organic segment and an amphiphilic polymer.Unfortunately,these encapsulated nanomaterials suffer from some inherent problems,such as leakage and detachment in in vivo applications,which largely limit clinic applications.In this paper,two high water solubility polymers with high photothermal therapy efficiency were prepared,which can be self-assembled into nanoparticles that have high photothermal conversion efficiency and great stability.More importantly,these two nanoparticles can be applied for high resolution imaging due to the photoacoustic or NIR-II imaging.The specific contents of this paper are as follows:?1?Synthesis of theranostic for Photoacoustic Imaging&active-target Photothermal Therapy:Atom transfer radical polymerization and click reaction were used in sequence to prepare PLAC-PDI,quickly self-assembled into NPs through hydrophobic-hydrophobic interaction with hydrophobic PDI segments as the core and hydrophilic glycopolymer segments PLAC as the protective shell.The high density of lactose on the surface of NPs brings good water solubility and physiological stability to the nanoparticles,which also leads to the active-target ability of Hep G2tumor cells.PLAC-PDI NPs has a smaller size?average particle size of 65±5 nm?,better near infrared absorption characteristics?660-700 nm?,and stronger absorbance(the molar extinction coefficient is 0.97 L g^-1 cm^-1)?With the irradiation of 730 nm laser at the power density of 500 mW cm^-2,PLAC-PDI NPs aqueous(0.60 mg mL^-1)can be up to 70?,and heat conversion efficiency can reach 42%.Meanwhile,High brightness photoacoustic imaging can be realized at 700 nm for Hep G2 cells and tumors.More importantly,Hep G2 cells and tumors can also be specifically killed under the 730nm laser irradiation with enhanced inhibitory efficiency.Finally,the good biocompatibility of PLAC-PDI NPs was be evidenced by H&E staining.?2?Synthesis of high solubility theranostic for NIR-II Imaging&Photothermal Therapy:Stille polymerization and Atom transfer radical polymerization were used in sequence to prepare tri-block conjugatedpolynmerPOEGMA-b-PDPP-b-POEGMAwithobviousNIR-II emission.POEGMA-b-PDPP-b-POEGMA has higher water-solubility(>10 mg mL^-1),smaller size?average particle size of 56.1±2.2 nm?,better near infrared absorption characteristics?Max absorption peak is 714 nm?,stronger absorbance and emission(the molar extinction coefficient is2.04 L g^-1 cm^-1,max emission is 1073 nm).With the irradiation of 808 nm laser at the power density of 500 mW cm^-2,POEGMA-b-PDPP-b-POEGMA aqueous(0.50 mg mL^-1)can be up to 65?in300 seconds,and heat conversion efficiency can reach 52%.The high penetration imaging of tumor can be obtained by POEGMA-b-PDPP-b-POEGMA due to the 7 mm imaging depth.Finallly,Hep G2 cells and tumors can be effectively damaged by POEGMA-b-PDPP-b-POEGMA under the 808nm laser irradiation with enhanced inhibitory efficiency.