Platelettargeting

Platelettargeting, in a biomedical context, refers to strategies that direct therapeutic or diagnostic agents to platelets themselves or to sites where platelets accumulate. The goal is to exploit platelets’ natural biology—their circulation, rapid recruitment to injured or diseased tissue, and diverse surface receptors—to improve targeting, efficacy, and safety of treatments or imaging.

Platelets are small, anucleate blood cells that participate in hemostasis and wound healing. They express adhesion receptors such as GPIb-IX-V, GPVI, and GPIIb/IIIa, enabling interactions with von Willebrand factor, collagen, fibrinogen, and activated endothelium. Upon activation, they release cargo and form aggregates, contributing to clot formation and inflammatory signaling. Tumor vessels and inflammatory lesions can recruit platelets, making platelet-rich microenvironments attractive targets for drug delivery and disease imaging.

Approaches to platelet targeting include: using platelets as drug carriers by loading them with therapeutics; engineering nanoparticles with platelet membranes or platelet-binding ligands to confer platelet-like homing; and decorating carriers with platelet-targeting moieties such as antibodies, aptamers, or peptides against P-selectin, GPVI, or GPIIb/IIIa to enhance adhesion to activated platelets or platelet-rich lesions. Platelet-derived extracellular vesicles are also explored as natural delivery vehicles, and some strategies use platelet membranes to cloak nanoparticles for immune evasion and targeted delivery.

Applications span oncology, where targeting the tumor vasculature and circulating tumor cells is explored; vascular injury and bleeding disorders; inflammatory diseases; and diagnostic imaging to visualize platelet-rich pathologies. Challenges include safety concerns such as thrombosis and bleeding risk, potential immunogenicity, manufacturing and standardization, and regulatory hurdles. Most work remains in preclinical stages, with ongoing efforts to translate platelet-targeting concepts into clinical practice. See also platelet-based therapy and targeted drug delivery.