Force-activatable biosensor enables single platelet force mapping directly by fluorescence imaging

• Published in: Biosensors & bioelectronics 2018-02, Vol.100, p.192-200
• Main Authors: Wang, Yongliang, LeVine, Dana N., Gannon, Margaret, Zhao, Yuanchang, Sarkar, Anwesha, Hoch, Bailey, Wang, Xuefeng
• Format: Article
• Language: English
• Subjects: Animals; biophysics; Biosensing Techniques - instrumentation; Biosensing Techniques - methods; biosensors; blood platelets; Blood Platelets - cytology; Blood Platelets - drug effects; Blood Platelets - metabolism; cell adhesion; Cell Adhesion - drug effects; Cellular force mapping; Dogs; Drug Evaluation, Preclinical - instrumentation; Drug Evaluation, Preclinical - methods; drugs; Equipment Design; fluorescence; Force-activatable biosensor; hemostasis; Humans; image analysis; Integrin tension sensor; integrins; Integrins - metabolism; Optical Imaging - instrumentation; Optical Imaging - methods; Platelet Activation - drug effects; Platelet adhesion; Platelet Aggregation Inhibitors - pharmacology; Platelet contraction; thrombosis; Tirofiban; Tyrosine - analogs & derivatives; Tyrosine - pharmacology
• ISSN: 0956-5663; 1873-4235
• DOI: 10.1016/j.bios.2017.09.007

Integrin-transmitted cellular forces are critical for platelet adhesion, activation, aggregation and contraction during hemostasis and thrombosis. Measuring and mapping single platelet forces are desired in both research and clinical applications. Conventional force-to-strain based cell traction force microscopies have low resolution which is not ideal for cellular force mapping in small platelets. To enable platelet force mapping with submicron resolution, we developed a force-activatable biosensor named integrative tension sensor (ITS) which directly converts molecular tensions to fluorescent signals, therefore enabling cellular force mapping directly by fluorescence imaging. With ITS, we mapped cellular forces in single platelets at 0.4µm resolution. We found that platelet force distribution has strong polarization which is sensitive to treatment with the anti-platelet drug tirofiban, suggesting that the ITS force map can report anti-platelet drug efficacy. The ITS also calibrated integrin molecular tensions in platelets and revealed two distinct tension levels: 12–54 piconewton (nominal values) tensions generated during platelet adhesion and tensions above 54 piconewton generated during platelet contraction. Overall, the ITS is a powerful biosensor for the study of platelet mechanobiology, and holds great potential in antithrombotic drug development and assessing platelet activity in health and disease. •A biosensor was developed to directly convert cell-generated molecular tensions to fluorescence.•This biosensor enables cellular force mapping with submicron resolution and piconewton sensitivity.•Single platelet force was mapped at 0.4µm resolution for the first time.•Platelet force polarization was revealed and the force range at the molecular level was determined.