Polysaccharides are becoming increasingly developed as
therapeutics and medical products, as the new field of Glycomics expands.
Glycosaminoglycans that contain
N-acetyl glucosamine constituents have been the focus of research leading to medical devices. A new
hemostatic bandage, the
Syvek Patch, has been introduced in the recent past for the control of
bleeding at vascular access sites in interventional cardiology and radiology procedures. This product consists of
poly-N-acetyl glucosamine (pGlcNAc) isolated in a unique fiber crystalline structural form from the large-scale culture and processing of a marine diatom. The
Syvek pGlcNAc fiber material has chemical, physical, and
biological properties that result in its favorable performance as a hemostat. Two new products, the Clo-Sur PAD and ChitoSeal, have recently become available also as patch hemostats. These two products both use
chitosan, another
N-acetyl glucosamine containing
glycosaminoglycan, as their active ingredient. Structural, chemical, and
biological comparisons of
Syvek pGlcNAc and
chitosan reveal a number of important differences.
Syvek pGlcNAc fibers contain approximately 50 fully acetylated, high molecular weight pGlcNAc molecules in a crystalline, three-dimensional beta structure array, and are insoluble.
Chitosan is a low molecular weight mixed amorphous cationic
polymer with no regular structure as a solid, and is water-soluble taking on a random coil configuration when in
solution. These structural dissimilarities result in differences in the
hemostatic properties of the two materials.
Syvek pGlcNAc is able to significantly reduce the in vitro
fibrin clot formation time of platelet-rich plasma samples and has the ability to cause aggregation of red blood cells in vitro.
Chitosan is no better than gauze or other controls in these in vitro assays. The
Syvek Patch is able to control the
bleeding and cause hemostasis in a coagulopathic swine spleen-
bleeding animal model 100% of the time, whereas Clo-Sur PAD was completely unsuccessful (0%) and ChitoSeal (25%) was worse than a gauze pad control (50%) in the same model.
Syvek pGlcNAc fibers have structural and chemical properties that provide a unique basis for their ability to interact with blood components to cause hemostasis.
Chitosan does not have the same properties and capabilities.