Multistability in platelets and their response to gold nanoparticles

Area of Science:

• Biomedical Engineering
• Nanotechnology
• Hematology

Background:

• Platelet aggregation can be triggered by gold nanoparticles (AuNP).
• Platelet response to AuNP is size-dependent, increasing as size decreases.
• AuNP interaction with platelets may indicate thrombotic risk from nano-drugs.

Purpose of the Study:

• To investigate the nanoparticle (NP) response of platelets.
• To determine the influence of platelet preactivation on NP response.
• To explore the relationship between AuNP size and platelet aggregation.

Main Methods:

• Assessing platelet aggregation and de-aggregation in response to varying AuNP sizes and platelet preactivation states.
• Measuring NP-induced platelet activation markers: release reaction, tyrosine phosphorylation, and CD62P expression.
• Quantifying AuNP uptake by platelets using fluorescence quenching.

Main Results:

• Platelet response to AuNP is critically dependent on preactivation by agonists like ADP.
• A transition from de-aggregatory to aggregatory state occurs with AuNP in preactivated platelets.
• Platelet response monotonically increases with decreasing AuNP size, with higher uptake of smaller NPs (18 nm vs. 68 nm).
• Adhered platelets respond differently to NPs compared to suspended platelets, influenced by shear-induced preactivation.

Conclusions:

• Platelet preactivation state significantly modulates their response to AuNP.
• Smaller AuNP sizes lead to greater platelet aggregation and uptake.
• AuNP interaction with platelets can serve as a biomarker for assessing thrombotic risk associated with nano-drugs.