Photodynamic therapy(PDT)is a new and rapidly developing treatment modality for dinical cancer therapy.Semiconductor polymer dots(Pdots)doped with photosensitizers have been successfully applied to PDT,and have made p...Photodynamic therapy(PDT)is a new and rapidly developing treatment modality for dinical cancer therapy.Semiconductor polymer dots(Pdots)doped with photosensitizers have been successfully applied to PDT,and have made progress in the field of tumor therapy.However,the problems of severe photosensitivity and limited tisue penetration depth are needed to be solved during the implementation process of PDT.Here we developed the Pdots doped with photosensitizer molecule Chlorin e6(Ce6)and photochromic molecule 1,2-bis(2,4-dimethy1-5 phenyl-3-thiophene)-3,3,4,5-hexafuoro-1-cyclopentene(BTE)to construct a photoswitchable nanoplatform for PDT.The Ce6-BTE-doped Pdots were in the green region,and the tissue penetration depth was increased compared with most Pdots in the blue region.The reversible conversion of BTE under different light irradiation was utilized to regulate the photodynamic effect and solve the problem of photosensitivity.The prepared Ce6-BTE-doped Pdots had small size,excellent optical property,efficient ROS generation and good photoswitchable ability.The cellular uptake,cytotoxicity,and photodynamic effect of the Pdots were detected in human colon tumor cells.The experiments in vitro indicated that Ce6-BTE-doped Pdots could exert excellent photodynamic effect in ON state and reduce photosensitivity in OFF state.These results demonstrated that this nanoplatform holds the potential to be used in clinical PDT.展开更多
As a hybrid imaging technique, photoacoustic imaging （PAI） can provide multiscale morphological information of tissues, and the use of multi-spectral PAI （MSPAI） can recover the spatial distribution of chromophore...As a hybrid imaging technique, photoacoustic imaging （PAI） can provide multiscale morphological information of tissues, and the use of multi-spectral PAI （MSPAI） can recover the spatial distribution of chromophores of interest, such as hemoglobin within tissues. Herein, we developed a contrast agent that can very effectively combine multiscale PAI with MSPAI for a more comprehensive characterization of complex biological tissues. Specifically, we developed novel PIID-DTBT based semi-conducting polymer dots （Pdots） that show broad and strong optical absorption in the visible-light region （500-700 nm）. The performances of gold nanoparticles （GNPs） and gold nanorods （GNRs）, which have been verified as excellent photoacoustic contrast agents, were compared with that of the Pdots based on the multiscale PAI system. Both ex vivo and in vivo experiments demonstrated that the Pdots have better photoacoustic conversion efficiency at 532 nm than GNPs and showed similar photoacoustic performance with GNRs at 700 nm at the same mass concentration. Photostability and toxicity tests demonstrated that the Pdots are photostable and biocompatible. More importantly, an in vivo MSPAI experiment indicated that the Pdots have better photoacoustic performance than the blood and therefore the signals can be accurately extracted from the background of vascular-rich tissues. Our work demonstrates the great potential of Pdots as highly effective contrast agents for the precise localization of lesions relative to the blood vessels based on multiscale PAI and MSPAI.展开更多
基金supported by the science and technology research project of education department of Jilin province(JJKH20211189KJ)Jilin province medical and health talents special project.
文摘Photodynamic therapy(PDT)is a new and rapidly developing treatment modality for dinical cancer therapy.Semiconductor polymer dots(Pdots)doped with photosensitizers have been successfully applied to PDT,and have made progress in the field of tumor therapy.However,the problems of severe photosensitivity and limited tisue penetration depth are needed to be solved during the implementation process of PDT.Here we developed the Pdots doped with photosensitizer molecule Chlorin e6(Ce6)and photochromic molecule 1,2-bis(2,4-dimethy1-5 phenyl-3-thiophene)-3,3,4,5-hexafuoro-1-cyclopentene(BTE)to construct a photoswitchable nanoplatform for PDT.The Ce6-BTE-doped Pdots were in the green region,and the tissue penetration depth was increased compared with most Pdots in the blue region.The reversible conversion of BTE under different light irradiation was utilized to regulate the photodynamic effect and solve the problem of photosensitivity.The prepared Ce6-BTE-doped Pdots had small size,excellent optical property,efficient ROS generation and good photoswitchable ability.The cellular uptake,cytotoxicity,and photodynamic effect of the Pdots were detected in human colon tumor cells.The experiments in vitro indicated that Ce6-BTE-doped Pdots could exert excellent photodynamic effect in ON state and reduce photosensitivity in OFF state.These results demonstrated that this nanoplatform holds the potential to be used in clinical PDT.
基金Acknowledgements This study was supported by the University of Macao in Macao （Nos. MYRG2014-00093-FHS, MYRG 2015-00036-FHS, and MYRG2016-00110-FHS）, Macao government （Nos. FDCT 026/2014/A1 and FDCT 025/2015/A1）, and the National Natural Science Foundation of China （No. 11434017）.
文摘As a hybrid imaging technique, photoacoustic imaging （PAI） can provide multiscale morphological information of tissues, and the use of multi-spectral PAI （MSPAI） can recover the spatial distribution of chromophores of interest, such as hemoglobin within tissues. Herein, we developed a contrast agent that can very effectively combine multiscale PAI with MSPAI for a more comprehensive characterization of complex biological tissues. Specifically, we developed novel PIID-DTBT based semi-conducting polymer dots （Pdots） that show broad and strong optical absorption in the visible-light region （500-700 nm）. The performances of gold nanoparticles （GNPs） and gold nanorods （GNRs）, which have been verified as excellent photoacoustic contrast agents, were compared with that of the Pdots based on the multiscale PAI system. Both ex vivo and in vivo experiments demonstrated that the Pdots have better photoacoustic conversion efficiency at 532 nm than GNPs and showed similar photoacoustic performance with GNRs at 700 nm at the same mass concentration. Photostability and toxicity tests demonstrated that the Pdots are photostable and biocompatible. More importantly, an in vivo MSPAI experiment indicated that the Pdots have better photoacoustic performance than the blood and therefore the signals can be accurately extracted from the background of vascular-rich tissues. Our work demonstrates the great potential of Pdots as highly effective contrast agents for the precise localization of lesions relative to the blood vessels based on multiscale PAI and MSPAI.
