Synthetic platelets have been developed by UC Santa Barbara researchers, in collaboration with researchers at Scripps Research Institute and Sanford-Burnham Institute in La Jolla, Calif. Their findings are published in the journal Advanced Materials in a paper titled "Platelet Mimetic Particles for Targeting Thrombi in Flowing Blood."
Platelets are the components of blood that allow it to prevent excessive bleeding and to heal wounds. The unique physical and biochemical properties of platelets play an important role in performing these complex biological tasks. Smaller than red blood cells, platelets are flexible, disk-shaped cells that are 2-4 micrometers in size.
"Upon further optimization and exhaustive testing, the synthetic platelets could be used for various biomedical applications," said the paper's first author Nishit Doshi, a researcher from the Department of Chemical Engineering.
The challenge Doshi and colleagues faced was to develop a comparably sized particle -- roughly 1/50th of the diameter of a strand of hair -- that had key structural properties of real platelets.
"In order to mimic the size, shape, and surface functionality of natural platelets synthetically, polymeric particles are particularly attractive," said Doshi. "However, polymeric particles are orders of magnitude more rigid than platelets."
To solve the problem of flexibility, researchers at UC Santa Barbara used a polymeric "template" -- a core upon which layers of proteins and polyelectrolytes were deposited, layered, and crosslinked to create a stable synthetic platelet-shaped particle. The rigid polymeric core was then dissolved to give the particle the desired flexibility. The particle was then coated with proteins found on the surface of activated natural platelets or damaged blood vessels, a procedure performed by the researchers at Scripps Research Institute.
These synthetic platelets may be used to not only perform the typical functions of human platelets; but may also be used to carry imaging agents to identify damaged blood vessels or to deliver drugs that dissolve blood clots.