Synthetic artificial platelets: Design, structure, properties.

Platelets are blood cells essential for hemostasis, and their deficiency risks severe bleeding during trauma or surgery. Donor platelet transfusions remain standard therapy but face significant limitations. Artificial platelets, particles mimicking key platelet functions, have emerged as a promising alternative. The artificial platelets can accumulate in vascular damage areas. Another natural platelets property, to "recognize" cancer cells, is also used in the design of biomimetic particles. In this review we describe platelets-inspired synthetic systems. We analyze the selection of functional targets, the types of ligands (proteins or peptides), carrier types and linkers, as well as strategies for selective activation at the sites of vascular injury. The artificial platelets are considered as platforms for drug delivery. The status of clinical and preclinical trials is summarized. The review critically assesses biocompatibility and immunological risks of artificial platelets structural components. We predict the most promising areas for further development of platelet-like systems: micro particle size and flexibility, material safety, the use of linkers, and heteromultivalent ligand decoration. The review provides a roadmap for the development of synthetic artificial platelets, with the aim of translating them into clinically relevant materials.