Hydrophobically Modified Chitosan Latches Onto Blood Cells And Assembles Them Into A Gel

A new type of bandage, made with a chemically modified version of the polysaccharide chitosan, may offer an inexpensive way to speed up wound healing in trauma centers and on the battlefield. By attaching benzene-n-octadecyl tails to the backbone of chitosan, a team led by University of Maryland’s Srinivasa R. Raghavan created an amphiphilic biopolymer, dubbed hm-chitosan, which causes blood to thicken into a gel that’s similar to a blood clot. Gel­ling occurs when the hm-chitosan’s hydrophobic tails hook into the membranes of blood cells and platelets via hydrophobic interactions, causing them to clump together. Raghavan likened the phenomenon to a nanoscale version of Velcro, which fastens to a looped fabric by virtue of tiny hooks. What’s more, when α-cyclodextrin is added to the gelled blood, it will liquefy again. Raghavan and his former student Matthew Dowling set up a company, Remedium Technologies, to commercialize the technology. Raghavan also published an account in Biomaterials earlier this year (DOI: 10.1016/j.biomaterials.2010.12.033).