Palladium‐Based Metallic Glass with High Thrombogenic Resistance for Blood‐Contacting Medical Devices

Abstract

Advancements in the design of mechanical blood circulatory devices have greatly improved patient survival rates, but currently employed metals still provoke a thrombosis response upon contact with blood, with potential lifethreatening consequences. While coating strategies have been developed to address this limitation, they possess inherent drawbacks such as susceptibility to crack formation and delamination. Herein, an amorphous metal based on palladium (Pd) is scrutinized and reveals substantial thrombogenic resistance compared to a state-of-the-art titanium alloy. In vitro assessment with human whole blood shows that the Pd glass provokes reduced platelet activation (lower expression of CD62P, CD41/CD61) and greatly retarded fibrin formation, but pronounced platelet spreading therewith challenging the dogma that platelet spreading equals activation. Mechanistic analysis of the early biomaterial-blood interactions reveals that conformational changes of adhered fibrinogen, and modified α IIb β 3 integrin expression and distribution across adhered platelets, underlay the superior performance of Pd glass. The study is accompanied by structural and thermophysical bulk investigations and physicochemical surface characterization to link the materials properties with the observed blood response. The results reveal a remarkable potential of Pd-based glass as direct blood-contacting bulk material without the need for coating.

Review on Biocompatibility and Prospect Biomedical Applications of Novel Functional Metallic Glasses

“…The Pd 77.5 Si 16.5 Cu 6 composition [ 185 ] with a smaller number of harmful elements, very recently demonstrated excellent hemocompatibility and thrombogenic resistance preventing the platelets aggregation and activation in comparison to Ti-6Al-4V alloy. This results in the possible application of this BMG for stents or blood-pumping devices with a low risk of causing thrombosis.…”

Surface Chemistry Dictates the Osteogenic and Antimicrobial Properties of Palladium‐, Platinum‐, and Titanium‐Based Bulk Metallic Glasses

“…One possible explanation for this may be the differential adsorption of fibrinogen modulating the conformation of platelet attachment. [ 25 ] However, the platelet morphology across all surfaces was comparable, featuring a dendritic shape, long pseudopodia, and partial aggregation. This suggests that either the surface chemistry or ions being released from the surface might play a role in steering the fate of blood interactions with BMGs.…”

“…[ 24 ] However, less is known about how the composition of BMGs can steer their bioactivity. The potential use of BMGs for blood‐contacting devices was recently reported, showing that Pd 77.5 Si 16.5 Cu 6 exhibits higher thrombogenic resistance than Ti64 in vitro, [ 25 ] indicating that the thrombogenic properties of BMGs, and thus their application, can be tailored based on their chemical composition. In another study, Pt 57.5 Cu 14 .…”

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

“…[40][41][42][43] The location of 𝛾-chain after HPF adsorption is critical in platelet adhesion and can be identi-fied using antibodies. [44] Thus, the bioactivity of 𝛾 400-411 on HPFcoated ( 110) and (001) rutile facets was quantitatively examined in this study by the immunofluorescence technique and linked with previously determined HPF molecules conformation. [20] The results presented in Figure 4a show that the availability of 𝛾-chains is much higher on (001) compared to (110) facet, despite the same amount of adsorbed HPF on both surfaces.…”