After the body is injured, the first reaction is platelets. They will be activated immediately, changing from a resting disk-like shape to an activated fan-like shape, and aggregate to form a platelet clot, playing a primary hemostasis effect. Therefore, platelets play a vital role in the process of hemostasis. Platelet transfusion and blood transfusion are the most common and effective methods for the treatment of uncontrolled bleeding. In recent years, the construction of artificial platelets with carrier-loaded polypeptides has become a new research direction for hemostatic materials. Artificial platelets have many advantages such as easy synthesis, few side effects, and industrial production.
When nanoparticles are used as artificial platelets, the shape of nanoparticles plays an important role in the display of their physical and chemical properties and biological properties. Therefore, the shape of nanoparticles largely determines the hemostatic efficiency of artificial platelets. The biological recognition mechanism in the human body makes it easier to recognize spherical structures, while non-spherical nanoparticles can evade the body's clearance mechanism, prolong circulation time, and increase adhesion to the surface of blood vessels. The study of non-spherical artificial platelets with controllable morphology has brought new hopes for improving the efficiency of hemostasis.
At earlier time, the team of Zhang Jiwen, a researcher from the Shanghai Institute of Materia Medica, Chinese Academy of Sciences, invented a cubic nanomaterial that can achieve efficient hemostasis. The material uses γ-cyclodextrin (CD) as a unit. And γ-cyclodextrin is a cyclic structure compound composed of 8 glucose units, which is a safe and injectable pharmaceutical excipient. The cyclodextrin metal-organic framework (CD-MOF) uses cyclodextrin as the organic ligand and potassium ion as the inorganic metal center to coordinate to form a new type of drug carrier with high safety, which has a regular cubic shape.
Researchers have synthesized a cross-linked CD-MOF (CL-MOF) that removes potassium ions based on the cube's CD-MOF. CL-MOF is a highly networked cubic nanoparticle composed of cyclodextrin. The oligopeptide GRGDS was used to simulate the coagulation mechanism of fibrinogen, and the surface of the microparticles was functionally modified to construct a cube artificial platelet GS5-MOF.
The results of the in vivo mouse tail docking model show that the cube GS5-MOF can target the bleeding injury site, reduce the bleeding time and blood loss of mice by 90%, and play a vital role in its efficient hemostasis.