An Echogenic Clot Method for Thrombolysis Monitoring in Thrombotic Stroke Models

To demonstrate thrombolytic efficacy of a tissue plasminogen activator (tPA)-loaded echogenic liposome (TELIP) formulation in rabbit thrombotic stroke model (the most relevant animal for evaluation directed therapy ischemic stroke), we sought to develop means monitoring thrombus dissolution quantitatively by ultrasound imaging methods. We hypothesized that gas-free contrast agent can be incorporated into blood clots at concentration does not affect the tPA-mediated clot rate, while enabling quantitative assessment rate. Clots were formed from mixture whole blood, 1 M calcium chloride, human thrombin and varying amounts microcrystalline cellulose. Washed tubes weighed 30, 60 90 minutes after addition recombinant tPA (rtPA) porcine plasma (100 µg/ml). Clot echogenicity each time point was assessed using Philips HDI 5000 system an L12-5 linear array probe. Recorded Images underwent videodensitometric analysis converted image reflectivity mean gray scale values (MGSV). found 1.12 mg/ml cellulose (0.2 ml) provided optimal without affecting rates (0.3-0.6 mg/min.) caused rtPA. The rate measured agreed well with determined mass loss measurements (0.28% 0-time value/minute). This method will important demonstrating vivo potentially decreased hemorrhagic effects vehicles relative systemic administration free thrombolytic.