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Hemostasis is a surgical procedure which stops bleeding.
Hemostasis can be major problem encountered during surgery.
Surgeons and nurses often spend much of the procedure controlling blood loss.
The application of nanotechnology (through a hemostat solution) to a wound drastically decreases hemostasis time and reduces complications from blood transfusions.
Current hemostasis procedures fall into three categories: mechanical, thermal, and chemical.
Mecahnical procedures involve the use of pressure or ligatures, and thermal processes involve cauterization.
Typical chemical methods use agents which alter the platelet aggregation and cause vessels to constrict.
The discovery of the affect which self-assembling peptides have on hemostasis occurred as a biproduct of research on tissue regeneration in the central nervous system.
Researcher from MIT and the University of Hong Kong prepared various concentrations (1% wt./vol. to 4% wt./vol.) of hemostat solution utilizing the RADA16-I peptide.
The solution was then applied to surgical wounds in many types of tissue (brain, liver, spinal cord, femoral artery, and skin) in anesthetized laboratory rats.
In all cases, hemostasis was ahieved in no more than 15 seconds.
By comparison, hemostasis took up to 6 minutes in control rats.
The image below shows hemostasis occurring in the brain and femoral artery.
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A) Image of the brain and superior sagital sinus. B) A vein being cut. C) Bleeding of the vein. D) Image taken after application of peptide hemostat solution.
E) Image of the femoral artery. F) The artery being cut. G) The artery bleeding. H) Image taken after application of hemostat.
Image from Nanomedicine: Nanotechnology, Biology and Medicine, Volume 2, Issue 4, December 2006, Pages 207-215
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In the presence of the tissue, the peptides in the solution join together to form a nanofiber across different types of wounds.
The application of nanotechnology to hemostasis presents a few advantages.
Because of the size of the nanoparticle building blocks in the solution, the wound is covered in entirety.
Not only is the entier wound covered, but also the resulting fiber across the wound is flexible.
Flexibility is a key factor in pulsating tissue or high pressure bleeding where solid hemostasis methods typically fail.
A crucial aspect of the peptide solution is that it does not alter normal clotting functions.
Eventually, the nanofiber will be absorbed by the tissue for repair as it is biodegradable.
Sources:
Nanomedicine: Nanotechnology, Biology and Medicine, Volume 2, Issue 4, December 2006, Pages 207-215 | Nano hemostat solution: immediate hemostasis at the nanoscale, Ellis-Behnke et al.
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