The optimal incubation time for in vitro hemocompatibility testing: Assessment using polymer reference materials under pulsatile flow with physiological wall shear stress conditions

Abstract

During hemocompatibility testing, activation products may reach plateau values which can result in less distinction between hemocompatible and hemo‐incompatible materials. Of concern is an underestimation of the blood activation caused by the biomaterial of interest, which may result in a false assessment of hemocompatibility. To elucidate the optimal incubation time for in vitro hemocompatibility testing, we used the Haemobile circulation model with human whole blood. Blood from healthy volunteers was in vitro incubated under pulsatile flow with physiological wall shear stress conditions at 37°C for 30, 60, 120, or 240 min. Test loops containing low‐density polyethylene and polydimethylsiloxane served as low and high reference materials, that is, hemocompatible and hemo‐incompatible biomaterials, respectively. In addition, empty loops served as a negative reference. Thrombogenicity, platelet function, inflammatory response, coagulation, and hemolysis between references and incubation times were compared. We found that thrombogenicity and platelet function were significantly affected by both the duration of incubation and the type of material. In particular, thrombogenicity and platelet function assessments were affected by incubation time. We found that an exposure time of 60 min was sufficient, and for almost all variables an optimal incubation time to discriminate between the low and high reference material. © 2019 The Authors. Journal of Biomedical Materials Research Part B: Applied Biomaterials published by Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 107B: 2335–2342, 2019.

Comparison of animal and human blood for in vitro dynamic thrombogenicity testing of biomaterials

“…While the above study established the framework of the dynamic test system and also provided a new static thrombosis pre‐test method to estimate donor‐specific anticoagulation levels, several test conditions (e.g., blood species, test temperature, and test duration) that could impact thrombosis require further investigation to broaden our knowledge in this area. Several in vitro flow loop thrombogenicity test systems have been described by other research groups 9,13–24 . However, currently there are no widely accepted or standardized methods.…”

“…9,13-24 However, currently there are no widely accepted or standardized methods. Although different types of animal blood have been used as a substitute for human blood in flow loop thrombogenicity tests, 9,[13][14][15][16][17][18][19][20][21][22][23][24] and some studies have compared blood properties of different species under various experimental settings, [25][26][27][28][29][30][31][32] these studies did not evaluate whether it is appropriate or acceptable to use animal blood instead of fresh human blood for in vitro dynamic thrombogenicity testing. To address this issue, the current study aimed to compare and evaluate the ability of blood from humans and four common animal sources (ovine, bovine and porcine blood from live donors, and abattoir porcine blood) to differentiate materials based on their relative thrombogenicity potentials in our dynamic in vitro thrombogenicity test system.…”

How Crystallographic Orientation‐Induced Fibrinogen Conformation Affects Platelet Adhesion and Activation on TiO2

“…This is important especially when implants and long‐contact duration medical devices are involved. [ 36 ] The platelets activation can occur within several seconds to minutes after material implantation, after which other platelets start adhering and can be activated as well. [ 37 ] After 120 min, minimal adhesion was found on the (110) facet and platelets in majority preserved their round shape.…”

Vascular Polyurethane Prostheses Modified with a Bioactive Coating—Physicochemical, Mechanical and Biological Properties

“…In the case of blood-material tests, it was decided that we would perform an hour-long contact of the material with blood based on literature reports [52,53]. Tubulin is important for platelet mobilization, reshaping, and formation of pseudopod [54].…”

“…For dynamic testing, the samples were cylinders with an internal diameter of 5 mm and a length of 40 mm. Each sample was contacted with 5 mL of whole blood circulating in a flow system with a 20 mL/min flow for 1 h as recommended by the other authors [52]. After this time, the materials were rinsed with 0.9% NaCl and further analyzed.…”