@article{ed776cfd683744178f4b95da868f6a3e,
title = "Thrombin-Activatable Microbubbles as Potential Ultrasound Contrast Agents for the Detection of Acute Thrombosis",
abstract = "Acute deep vein thrombosis (DVT) is the formation of a blood clot in the deep veins of the body that can lead to fatal pulmonary embolism. Acute DVT is difficult to distinguish from chronic DVT by ultrasound (US), the imaging modality of choice, and is therefore treated aggressively with anticoagulants, which can lead to internal bleeding. Here we demonstrate that conjugating perfluorobutane-filled (PFB-filled) microbubbles (MBs) with thrombin-sensitive activatable cell-penetrating peptides (ACPPs) could lead to the development of contrast agents that detect acute thrombosis with US imaging. Successful conjugation of ACPP to PFB-filled MBs was confirmed by fluorescence microscopy and flow cytometry. Fluorescein-labeled ACPP was used to evaluate the efficiency of thrombin-triggered cleavage by measuring the mean fluorescence intensity of ACPP-labeled MBs (ACPP-MBs) before and after incubation at 37 °C with thrombin. Lastly, control MBs and ACPP-MBs were infused through a tube containing a clot, and US contrast enhancement was measured with or without the presence of a thrombin inhibitor after washing the clot with saline. With thrombin activity, 91.7 ± 14.2% of the signal was retained after ACPP-MB infusion and washing, whereas only 16.7 ± 4% of the signal was retained when infusing ACPP-MBs in the presence of hirudin, a potent thrombin inhibitor.",
keywords = "DVT, activatable, cell-penetrating peptide, microbubble, thrombin, thrombosis, ultrasound",
author = "Jacques Lux and Vezeridis, {Alexander M.} and Kenneth Hoyt and Adams, {Stephen R.} and Armstrong, {Amanda M.} and Sirsi, {Shashank R.} and Mattrey, {Robert F.}",
note = "Funding Information: J.L. and R.F.M. designed the experiments. J.L., A.M.V., A.M.A., and S.R.A. performed the experiments. J.L., A.M.V., and A.M.A. collected the data. J.L. and K.H. processed the imaging data. J.L., K.H., and R.F.M. analyzed and interpreted the data. S.R.S. contributed to the MB formulation. J.L., S.R.S., and R.F.M. performed the literature review. J.L. and R.F.M. wrote and edited the manuscript. The manuscript was written through contributions of all authors. All authors have given approval to the final version of the manuscript. Funding This work was supported in part by the Cancer Prevention and Research Institute of Texas (CPRIT) Grant RR150010 and NIH Grants K25EB017222 and R21CA212851. R.F.M. is a CPRIT Established Investigator. A.M.V. was supported in part by T32-EB005970 and the Radiological Society of North America Presidents Circle Research Resident Grant RR 1472. Research reported in this publication was supported by the National Center for Advancing Translational Sciences of the National Institutes of Health under the Center for Translational Medicine{\textquoteright}s award UL1TR001105. The content is solely the responsibility of the authors and does not necessarily represent the official views of the NIH. Notes The authors declare no competing financial interest. Publisher Copyright: {\textcopyright} 2017 American Chemical Society.",
year = "2017",
month = nov,
day = "1",
doi = "10.1021/acsami.7b10592",
language = "English (US)",
volume = "9",
pages = "37587--37596",
journal = "ACS Applied Materials and Interfaces",
issn = "1944-8244",
publisher = "American Chemical Society",
number = "43",
}