Comparison of structural and hemostatic properties of the poly‐N‐acetyl glucosamine Syvek Patch with products containing chitosan

Abstract

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.

Hemostatic properties of glucosamine‐based materials

“…A new polymeric fiber material, poly-N-acetyl glucosamine (p-GlcNAc), formulated as patches and lyophilized pads, has been shown to be effective in achieving hemostasis in surgical procedures and trauma. [1][2][3][4][5][6][7] The p-GlcNAc fiber material is isolated and purified from large scale cultures of a marine microalga/diatom. 8 An investigation of the physical and chemical properties of the p-GlcNAc fibers was carried out to determine how they structurally and functionally differ from chitin, chitosan, and other N-acetyl glucosamine containing compounds.…”

“…These observations allow us to better understand prior observations of differences in hemostatic function. 5 N-acetyl glucosamine polymers occur in natural products such as chitin, which can be deacetylated chemically or enzymatically to produce glucosamine polymers referred to as chitosan. Chitosan, which is a chemically heterogeneous mixture of polymers with 10-20% N-acetyl residues and 80-90% glucosamine residues, 3 can also be extracted from crustacean exoskeletons and fungal mycelial mats.…”

“…11 Chitin-and chitosan-based products have been advanced for a wide variety of applications, including wound healing, 12 pharmaceutical formulation, [12][13][14][15][16] tissue engineering, [17][18][19][20][21] and surface hemostasis. 22,23 However, medical product development with these materials has been hampered by the chemical and physical heterogeneity of the polymer products and contamination of preparations by proteins and other components. 3 Recently discovered nanofibers isolated from a marine microalgal source 3 consist of high molecular weigh (MW ¼ 2.8 Â 10 6 Da) linear polymers of fullyacetylated poly-N-acetyl glucosamine.…”

Treatment of dialysis access puncture wound bleeding with chitosan dressings

“…3 Improved hemostasis dressings with active clotting surfaces and components have been recently reported in trauma and other literature to accelerate hemostasis in moderate to severe bleeding. 4,5 We investigated the safety and efficacy of a chitosan-based dressing (HemCon Bandage, HemCon, Portland, Ore.) to improve hemostasis at dialysis site punctures and to reduce the need for compressive devices.…”

Diagnostic Cerebral Angiography

“…52 (b) These topical agents cannot be expected to produce the same security of hemostasis as the closure devices described below, especially if the sheath size is greater than 5F. 5.…”