Anti-Thrombogenicity Study of a Covalently-Attached Monolayer on Stent-Grade Stainless Steel

Abstract

Implantable devices fabricated from austenitic type 316L stainless steel have been employed significantly in medicine, principally because the material displays excellent mechanical characteristics and corrosion resistance. It is well known, however, that interaction of exposure of such a material to blood can initiate platelet adhesion and blood coagulation, leading to a harmful medical condition. In order to prevent undesirable surface platelet adhesion on biomaterials employed in procedures such as renal dialysis, we developed an ultrathin anti-thrombogenic covalently attached monolayer based on monoethylene glycol silane chemistry. This functions by forming an interstitial hydration layer which displays restricted mobility in the prevention of surface fouling. In the present work, the promising anti-thrombogenic properties of this film are examined with respect to platelet aggregation on 316L austenitic stainless steel exposed to whole human blood. Prior to exposure with blood, all major surface modification steps were examined by X-ray photoelectron spectroscopic analysis and surface free-angle measurement by contact angle goniometry. End-stage anti-thrombogenicity detection after 20 min of blood exposure at 100 s−1, 300 s−1, 600 s−1, 750 s−1, and 900 s−1 shear rates revealed that a significant reduction (>90%) of platelet adhesion and aggregation was achieved for surface-modified steel, compared with untreated material. This result is confirmed by experiments conducted in real time for 60-minute exposure to blood at 100 s−1, 600 s−1, and 900 s−1 shear rates.

A Vascular Graft On‐a‐Chip Platform for Assessing the Thrombogenicity of Vascular Prosthesis and Coatings with Tuneable Flow and Surface Conditions

“…Current methods of in vitro thrombogenicity testing involve the use of static, agitating, and or shear-flow systems. [60,61] Miniaturized parallel plate and microfluidic flow platforms have also been described, [62,63] but fail to incorporate physiologicallike testing with blood flow, vascular prosthesis, coatings, and endothelial cells in a singular device. These platforms moreover overlook the control and versatility of microscale perfusion as an advantage for the testing and translation of novel prosthesis and or coatings in vitro.…”

Enhanced Hemocompatibility and Cytocompatibility of Stainless Steel

“…Researchers are exploring numerous approaches for stent surface modifications to finely tune platelet interactions, optimize biocompatibility, and ultimately enhance the overall efficacy and safety of these medical devices in cardiovascular applications. For instance, to inhibit platelet adhesion and aggregation on SS316L SS, Yang et al 44 developed an antithrombogenic coating based on monoethylene glycol silane, which demonstrated a significant (>90%) reduction in platelet adhesion and aggregation during exposure to whole human blood. Similarly, Carmagnola et al 45 modified the surface of SS316L stents with a layer-by-layer coating, e m p l o y i n g p o l y ( s t y r e n e s u l f o n a t e ) / p o l y -(diallyldimethylammonium chloride) and heparin, and inhibited platelet adhesion and activation.…”

Interaction of Pseudomonas aeruginosa with surface-modified silica studied by ultra-high frequency acoustic wave biosensor

“…Of the anti-fouling layers studied with the EMPAS system, hydroxyl terminated monoethylene glycol [2-(3-silylpropyloxy)-hydroxy-ethyl (MEG-OH)], which is added to surfaces as a trifluoroacetate protected version [2-(3-trichlorosilylpropyloxy)-ethyl trifluoroacetate (MEG-TFA)], proved to be the best at preventing surface adhesion from serum (Figure 2) [9]. This coating has been further studied on additional surfaces such as plastic polymers to prevent blood clotting [12][13][14], on steel to prevent blood clotting [15], and on polymers to reduce bacterial adhesion [16,17]. Typically, EMPAS studies whether in detection or fouling have used a flow rate of 50 μL/min in order to provide interaction time between any surface probes and the analyte of interest [11,18,19].…”