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Fradet, et al. (12) took these concepts further by using a gel of chitosan acetate to improve the graft sealing procedure and produce effective hemostasis under most severe bleeding conditions in dogs. Dutkiewicz, et al. (13) used chitosan as a biocompatible, resorbable coating for polyester vascular grafts and showed that the chitosan not only exhibited a superior hemostasis but also in vitro human blood anticoagulation. In dog trials with Dallon double vascular grafts, this group reported similarily effective results in vivo with no need to heparinize the dogs (14). Kochanska, et al. (15) recently cited very effective hemostasis using powdered chitosan ascorbate in cases of local bleeding from the gingiva, papilla interdentalis, endodontium and periodontium resulting from dental trauma.
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Some of the cited patented hemostasis technology has been licensed and some is under commercial consideration at this time. Nonetheless, as with the other biomedical applications, there remains much opportunity for additional discovery and development with these new biomaterials. The area of vascular graft sealants, in particular, seems most fertile and commercially interesting.