RGD peptides has been used to detect cell surface integrin and direct clinical effective therapeutic drug selection. Herein we report that a quick one step detection of cell surface marker that was realized by a speci...RGD peptides has been used to detect cell surface integrin and direct clinical effective therapeutic drug selection. Herein we report that a quick one step detection of cell surface marker that was realized by a specially designed NiF e-based magnetic biosensing cell chip combined with functionalized magnetic nanoparticles. Magnetic nanoparticles with 20-30 nm in diameter were prepared by coprecipitation and modified with RGD-4C, and the resultant RGD-functionalized magnetic nanoparticles were used for targeting cancer cells cultured on the NiF e-based magnetic biosensing chip and distinguish the amount of cell surface receptor-integrin.Cell lines such as Calu3, Hela, A549, CaF br, HEK293 and HUVEC exhibiting different integrin expression were chosen as test samples. Calu3, Hela, HEK293 and HUVEC cells were successfully identified. This approach has advantages in the qualitative screening test. Compared with traditional method, it is fast, sensitive, low cost,easy-operative, and needs very little human intervention. The novel method has great potential in applications such as fast clinical cell surface marker detection, and diagnosis of early cancer, and can be easily extended to other biomedical applications based on molecular recognition.展开更多
The development of high-resolution nanosized photoacoustic contrast agents is an exciting yet challenging technological advance. Herein, antibody (breast cancer-associated antigen I (Brcaal) monoclonal antibody)- ...The development of high-resolution nanosized photoacoustic contrast agents is an exciting yet challenging technological advance. Herein, antibody (breast cancer-associated antigen I (Brcaal) monoclonal antibody)- and peptide (RGD)- functionalized gold nanoprisms (AuNprs) were used as a combinatorial methodology for in situ photoacoustic imaging, angiography, and localized hyperthermia using orthotopic and subcutaneous murine gastric carcinoma models. RGD-conjugated PEGylated AuNprs are available for tumor angiography, and Brcaal monodonal antibody-conjugated PEGylated AuNprs are used for targeting and for in situ imaging of gastric carcinoma in orthotopic tumor models. In situ photoacoustic imaging allowed for anatomical and functional imaging at the tumor site. In vivo tumor angiography imaging showed enhancement of the photoacoustic signal in a time-dependent manner. Furthermore, photoacoustic imaging demonstrated that tumor vessels were clearly damaged after localized hyperthermia. This is the first proof-of-concept using two AuNprs probes as highly sensitive contrasts and therapeutic agents for in situ tumor detection and inhibition. These smart antibody/peptide AuNprs can be used as an efficient nanotheranostic platform for in vivo tumor detection with high sensitivity, as well as for tumor targeting therapy which, with a single-dose injection, results in tumor size reduction and increases mice survival after localized hyperthermia treatment.展开更多
Based on listed companies issuing bonds on the Shanghai and Shenzhen Stock Exchanges from 2007 to 2017, this study analyzes the relationship between significant risk warnings in Chinese companies’ annual reports and ...Based on listed companies issuing bonds on the Shanghai and Shenzhen Stock Exchanges from 2007 to 2017, this study analyzes the relationship between significant risk warnings in Chinese companies’ annual reports and corporate bond credit spreads. The main findings are as follows. First, in the Chinese market, ‘‘substantial warnings of significant risks' can significantly improve corporate bond credit spreads, reflecting the risk-warning effect;second,state-owned property rights weaken this effect, which only pertains to listed companies with poor risk management and low information quality;third, significant risk warnings increase investors’ heterogeneous beliefs, also affecting credit spreads;and fourth, through textual analysis, it is found that the corporate bond credit spread is greater when the disclosed risk factors are more pessimistic and less similar to those of the previous year. The findings of this paper help to enrich the literature on credit spreads and risk disclosure.展开更多
基金supported by National Key Basic Research Program (973 Project) (No. 2010CB933901 and 2011CB933100)National 863 Hi-tech Project of China (No. 2012AA022703), National Natural Scientific Fund (No. 81225010, 81101169 and 31100717)Shanghai Nano project (13NM1401500), Specialized Research Fund for the Doctoral Program of Higher Education (No. 20110073120072)
文摘RGD peptides has been used to detect cell surface integrin and direct clinical effective therapeutic drug selection. Herein we report that a quick one step detection of cell surface marker that was realized by a specially designed NiF e-based magnetic biosensing cell chip combined with functionalized magnetic nanoparticles. Magnetic nanoparticles with 20-30 nm in diameter were prepared by coprecipitation and modified with RGD-4C, and the resultant RGD-functionalized magnetic nanoparticles were used for targeting cancer cells cultured on the NiF e-based magnetic biosensing chip and distinguish the amount of cell surface receptor-integrin.Cell lines such as Calu3, Hela, A549, CaF br, HEK293 and HUVEC exhibiting different integrin expression were chosen as test samples. Calu3, Hela, HEK293 and HUVEC cells were successfully identified. This approach has advantages in the qualitative screening test. Compared with traditional method, it is fast, sensitive, low cost,easy-operative, and needs very little human intervention. The novel method has great potential in applications such as fast clinical cell surface marker detection, and diagnosis of early cancer, and can be easily extended to other biomedical applications based on molecular recognition.
基金This work was supported by the National Basic Research Program of China (No. 2015CB931802), National Natural Science Foundation of China (Nos. 81225010, 81327002, 31170961, 20771075, and 20803040), the National High-tech R&D Program of China (No. 2014AA020700), and Special project for nanotechnology from Shanghai (Nos. 13NM1401500 and 15DZ2252000).
文摘The development of high-resolution nanosized photoacoustic contrast agents is an exciting yet challenging technological advance. Herein, antibody (breast cancer-associated antigen I (Brcaal) monoclonal antibody)- and peptide (RGD)- functionalized gold nanoprisms (AuNprs) were used as a combinatorial methodology for in situ photoacoustic imaging, angiography, and localized hyperthermia using orthotopic and subcutaneous murine gastric carcinoma models. RGD-conjugated PEGylated AuNprs are available for tumor angiography, and Brcaal monodonal antibody-conjugated PEGylated AuNprs are used for targeting and for in situ imaging of gastric carcinoma in orthotopic tumor models. In situ photoacoustic imaging allowed for anatomical and functional imaging at the tumor site. In vivo tumor angiography imaging showed enhancement of the photoacoustic signal in a time-dependent manner. Furthermore, photoacoustic imaging demonstrated that tumor vessels were clearly damaged after localized hyperthermia. This is the first proof-of-concept using two AuNprs probes as highly sensitive contrasts and therapeutic agents for in situ tumor detection and inhibition. These smart antibody/peptide AuNprs can be used as an efficient nanotheranostic platform for in vivo tumor detection with high sensitivity, as well as for tumor targeting therapy which, with a single-dose injection, results in tumor size reduction and increases mice survival after localized hyperthermia treatment.
基金NSFC (71472188, 71672191)Humanities and Social Science Foundation (19YJC630040) for its support
文摘Based on listed companies issuing bonds on the Shanghai and Shenzhen Stock Exchanges from 2007 to 2017, this study analyzes the relationship between significant risk warnings in Chinese companies’ annual reports and corporate bond credit spreads. The main findings are as follows. First, in the Chinese market, ‘‘substantial warnings of significant risks' can significantly improve corporate bond credit spreads, reflecting the risk-warning effect;second,state-owned property rights weaken this effect, which only pertains to listed companies with poor risk management and low information quality;third, significant risk warnings increase investors’ heterogeneous beliefs, also affecting credit spreads;and fourth, through textual analysis, it is found that the corporate bond credit spread is greater when the disclosed risk factors are more pessimistic and less similar to those of the previous year. The findings of this paper help to enrich the literature on credit spreads and risk disclosure.