| Cancer phototheranostics that combines diagnosis with phototherapy,has emerged as a new mode of precise treatment.Nevertheless,taking highly effective phototheranostics into consideration,it is still a tremendous challenge to design multifunctional photothermal agents（PTAs）that combine the features of intensive near-infrared（NIR）absorption/emission,high photothermal conversion efficiency（PCE）and preferable tumor accumulation.Hereof,seeking a convenient method to facilitate absorption red-shift,promote the accumulation of drugs in tumors and heighten PCE appears to be particularly important for cancer theranostics.The specific work is as follows:（1）The J-aggregation of heavy-atom-free boron fluorodipyridine（BODIPY）can be easily tuned by adjusting the ratio of polar and non-polar solvents or adjusting the temperature.The electron configuration changes of BODIPY monomers and J-aggregates were investigated using density functional theory（DFT）,the results show that the ground-state energy gap（0.27 e V）of the J-aggregation model is significantly narrowed compared with the energy gap of the monomer（1.91 e V）,which is favorable for the transition of electrons from the ground state to the excited state,resulting in a red-shift of the absorption peak.（2）BODIPY assembled with F127 to fabricate J-aggregated nanoagents（named as BNPs）.Compared to free BODIPY,BNPs own the merits of maximum absorption redshift63 nm,deep-tissue fluorescence imaging,enhanced cellular uptake,preferable tumor targeting,elevated PCE,excellent photostability and water dispersibility.In vitro experiments showed that BNPs had strong phototoxicity to human cervical cancer（He La）and human lung cancer（A549）cells,with half-maximal inhibitory concentrations(IC50)of4.5 and 5.5μM,respectively.In vivo experiments demonstrated BNPs could behave as high-performance tumor-targeted fluorescent imaging probes and antitumor PTAs to conduct NIR imaging-guided photothermal therapy.This work provides a new J-aggregation platform for developing robust diagnostic and therapeutics agents. |
