Attenuation of Thrombin-Mediated Fibrin Formation via Changes in Fibrinogen Conformation Induced by Reaction with S-nitroso-N-acetylpenicillamine, but not S-nitrosoglutathione

Mercaptopyrimidine-templated gold nanoclusters for antithrombotic therapy

Here we report for the first time that mercaptopyrimidine-templated gold nanoclusters (DAMP-AuNCs) can be used as a novel anticoagulant candidate for the design of antithrombotic drugs. Anticoagulant mechanisms revealed that DAMP-AuNCs significantly inhibited thrombus formation by interacting with fibrinogen. Carrageenan-induced mice tail thrombosis model experiments showed that DAMP-AuNCs had antithrombotic efficacy comparable to heparin in vivo. More importantly, these ultrasmall AuNCs possess excellent blood compatibility and only induce negligible bleeding side effects. Our study is a successful attempt at developing novel antithrombotic agents with high biosafety.

An in vitro analysis of the hemostatic efficacy of fibrinogen precipitation with varied keratin fraction compositions

In preclinical studies, human hair has demonstrated effective hemostatic properties, potentially attributed to keratin proteins facilitating rapid conversion of fibrinogen to fibrin during coagulation. However, the rational use of human hair keratin for hemostasis remains unclear, given its complex mixture of proteins with diverse molecular weights and structures, leading to variable hemostatic capacity. To optimize the rational utilization of human hair keratin for hemostasis, we investigated the effects of different keratin fractions on keratin-mediated fibrinogen precipitation using a fibrin generation assay. Our study focused on high molecular weight keratin intermediate filaments (KIFs) and lower molecular weight keratin-associated proteins (KAPs) combined in various ratios during the fibrin generation. Scanning electron microscope analysis of the precipitates revealed a filamentous pattern with a broad distribution of fiber diameters, likely due to the diversity of keratin mixtures involved. An equal proportion of KIFs and KAPs in the mixture yielded the most extensive precipitation of soluble fibrinogen in an in vitro study, potentially due to structure-induced exposure of active sites. However, all hair protein samples exhibited diverse catalytic behaviors compared to thrombin, highlighting the potential of utilizing specific hair fractions to develop hair protein-based hemostatic materials with optimized capacity.