The transforming growth factor-β1 (TGF-β1)/Smad3 signal pathway is related to mutiple physiological and pathological generation mechanism of human being. Up to date, however, the spacial and time information on the phosphorylated Smad3 is still unclear. In this study, the process of Smad3 phosphorylation was observed under the physiological state in the living cells. Firstly, the ECFP-Smad3-Citrine (Smad3 biosensor) fusion protein expression vector was constructed and identified. Then the Smad3 biosensor was transfected into 293T cells. The transfection efficiency and the expressions of fusion proteins were observed in 24 hours. Thirdly, Smad3 biosensor flurorescence resonance energy transfer (FRET) was observed with the inversion fluorescence microscope and measured by the MetaFlour FRET 4.6 software. Smad3 biosensor transfection efficiency was nearly 40% and the fusion protein was seen under the fluorescence microscope. The FRET ratio of Smad3 biosensor in living 293T cells was decreased after 10 minutes incubation with the ligand of TGF-β1. The period of decreasing CFP and enhancing Citrine signals was about 300 seconds. With the technology of FRET, the TGF-β1/Smad3 signal pathway could be real time monitored dynamically under the physiological condition in living cells.
Continuous glucose monitoring plays an important role in severe diabetic patients. However, there is no available commercial implanted glucose biosensor for long-term clinic application. This paper firstly introduces the classification of biosensors for continuous glucose monitoring, and then discusses the failure mechanism for implanted biosensors. After that, it points out the routes and tips to improve the life time of the biosensor, and finally looks forward to the future development of implanted glucose biosensors.
Ultra-sensitive and quantitative analysis of proteins, nucleic acid, virus and other biochemical species are critical technologies for effective dianosis of disease, as well as medical studies. Silicon nanowires field-effect transistor (SiNWs-FET) biosensor is one of the most promising powerful platforms for label-free, real-time, ultra-sensitive detection of analyte. Here, the working principle of SiNWs-FET biosensor and the applications of SiNWs-FET biosensors in medicine were introduced. Moreover, the methods for enhancing the sensitivity of SiNWs-FET biosensor were discussed. Lastly, the prospecting of SiNWs-FET biosensor was presented.