Thrombin-inhibiting nanoparticles rapidly constitute versatile and detectable anticlotting surfaces

Area of Science:

• Biomaterials Science
• Cardiovascular Research
• Nanomedicine

Background:

• Acute cardiovascular disorders like atherosclerotic plaque erosion involve thrombosis.
• Current systemic anticoagulation therapies carry significant bleeding risks.
• Developing localized antithrombotic strategies is crucial for safer treatment.

Purpose of the Study:

• To design and evaluate thrombin-targeted nanoparticles (NPs) for localized antithrombotic surface creation.
• To assess the efficacy of these NPs in inhibiting thrombin activity and platelet deposition.
• To investigate the safety profile, particularly bleeding risks, compared to systemic anticoagulants.

Main Methods:

• Perfluorocarbon nanoparticles (PFC NPs) were functionalized with thrombin inhibitors (e.g., bivalirudin).
• In vitro assays (FPA ELISA, MRI) assessed clot inhibition and NP layer formation.
• In vivo studies in mice involved laser injury to the carotid artery to evaluate NP antithrombotic effects and bleeding times.

Main Results:

• Thrombin-inhibiting NPs effectively prevented fibrinogen cleavage by both free and clot-bound thrombin.
• In vitro MRI confirmed NPs prevented clot growth.
• In vivo, NPs significantly delayed arterial occlusion in mice with only transient effects on bleeding time.
• (19)F MRI confirmed NP localization and retention at arterial thrombi.

Conclusions:

• Thrombin-inhibiting NPs can create a localized antithrombotic surface, suppressing thrombosis effectively.
• These NPs offer a promising, safer alternative to systemic anticoagulation for acute vascular syndromes.
• The ability to image NP accumulation via MRI aids in monitoring treatment efficacy.