New synthetic platelets for better bleeding control

Scientists, including two of Indian-origin, have developed new synthetic platelets that mimic and outperform natural platelets at controlling bleeding.
Researchers at the University of California, Santa Barbara turned to the human body's own mechanisms for inspiration in dealing with the necessary and complicated process of coagulation.
By creating nanoparticles that mimic the shape, flexibility and surface biology of the body's own platelets, they were able to accelerate natural healing processes while opening the door to therapies and treatments that can be customised to specific patient needs.
"This is a significant milestone in the development of synthetic platelets, as well as in targeted drug delivery," said Samir Mitragotri, director UC Santa Barbara's Centre for Bioengineering (CBE).

The platelet-like nanoparticles (PLNs) behave just like their human counterparts and can be added to the blood flow to supply or augment the patient's own natural platelet supply, stemming the flow of blood and initiating the healing process, while allowing physicians and other caregivers to begin or continue the necessary treatment.
Emergency situations can be brought under control faster, injuries can heal more quickly and patients can recover with fewer complications, researchers said.

"We were actually able to render a 65 per cent decrease in bleeding time compared to no treatment," said graduate student researcher Aaron Anselmo, lead author of the paper.

According to Mitragotri and colleagues Stefano Menegatti and Sunny Kumar, the key lies in the PLNs' mimicry of the real thing.
By imitating the shape and flexibility of natural platelets, PLNs can also flow to the injury site and congregate there.
With surfaces functionalised with the same biochemical motifs found in their human counterparts, these PLNs also can summon other platelets to the site and bind to them, increasing the chances of forming that essential plug.
The platelets are engineered to dissolve into the blood after their usefulness has run out, minimising complications that can arise from emergency hemostatic procedures.

According to Anselmo's investigations, for the same surface properties and shape, nanoscale particles can perform even better than micron-size platelets.
This technology allows for customisation of the particles with other therapeutic substances - medications, therapies and such - that patients with specific conditions might need.
"This technology could address a plethora of clinical challenges," said Dr Scott Hammond, director of UCSB's Translational Medicine Research Laboratories.
With optimisable PLNs, physicians would be able to strike a fine balance between anticoagulant therapy and wound healing in older patients, by using nanoparticles that can target where clots are forming without triggering unwanted bleeding.

The findings appear in the journal ACS Nano.