In Vitro Blood Clot Formation and Dissolution for Testing New Stroke-Treatment Devices

Abstract

Strokes are among the leading causes of death worldwide. Ischemic stroke, due to plaque or other buildup blocking blood flow to the brain, is the most common type. Although ischemic stroke is treatable, current methods have severe shortcomings with high mortality rates. Clot retrieval devices, for example, can result in physically damaged vessels and death. This study aims to create blood clots that are representative of those found in vivo and demonstrate a new method of removing them. Static blood clots were formed using a 9:1 ratio of whole sheep blood and 2.45% calcium chloride solution. This mixture was heated in a water bath at 37 °C for approximately one hour until solidified. Following clot solidification, human plasmin was introduced by various methods, including soaking, injection, and membrane perfusion, and the resulting dissolution percentages were determined. Different clot types, representative of the wide range found physiologically, were also manufactured and their dissolution characteristics evaluated. A method to reproducibly create blood clots, characteristic of those found in vivo, is essential for the production of stroke retrieval devices that can efficiently and effectively remove clots from patients with low mortality rates and little/no damage to the surrounding vessels.

Bacterial Brain Abscesses Expand Despite Effective Antibiotic Treatment: A Process Powered by Osmosis Due to Neutrophil Cell Death

“…Cell-rich pus (23 samples) formed a clot that was highly viscous and resistant to mechanical dissolution. Incubation with bovine DNase for 30 minutes at 37°C led to complete dissolution of these clots ( Supplemental Digital Content 1 , Supplemental Figure 1 , http://links.lww.com/NEU/E43), whereas attempts to achieve this with plasmin 22 were unsuccessful (see Methods). This observation illustrated a role for DNA in pus viscosity and clot formation.…”

“…For clot dissolution, pus samples that had been stored at À80°C were weighed, thawed, and mixed with water 1:1. Vortexing (2500 rpm for 1 minute), trituration with a Pasteur glass pipette, and incubation with plasmin, 22 which targets fibrin, did not cause clot dissolution. We then incubated clotted pus (12-370 mg) with bovine DNase (Quantabio, Beverly, MA): 30 U/mL, final volume 1 mL, at 37°C for 30 minutes.…”

Lack of Interactions Between Alteplase/Tenecteplase and the Adenosine A1R/A3R Agonist AST-004

“…The ability of AST-004 to alter the thrombolytic activity of alteplase was evaluated with an in vitro assay utilizing human blood clots consistent with previously published methods. [6][7][8] In vitro thrombolysis was determined by measuring in vitro human clot weights at different time points following incubation with differing concentrations of AST-004 and alteplase (N=6 human subjects, unspecified sex/ethnicity, Lampire Biological Associates, Pipersville, PA). To each human clot segment placed in human plasma in test tubes, alteplase, at concentrations of 2000 or 3000 ng/mL, was added along with one of each of the vehicle control or AST-004 test groups.…”

The Link between Stroke Risk and Orodental Status—A Comprehensive Review

“…Neurons begin to die within minutes of the onset of stroke because their oxygen supply is cut off. The brain damage caused by a stroke can impair a person’s fundamental bodily functions such as movement, memory, and speech [ 25 , 26 ].…”