Sponges based on polymeric chitosan for biomedical application: Control and stagnation of bleeding and wound healing

Full text: An ideal hemostatic agent should be able to interrupt arterial and venous bleeding.Among the organic materials, it can be highlighted the group of hemostatic agents made from chitosan, which is a natural biopolymers with a high content of nitrogen (N) up to 7% [1] and a regular distribution of free amino groups, which once protonated by acidic groups behaves as a polycation molecule [2]. Chitosan has the the ability to bond with negatively charged substances such as lipids, proteins, dyes, among others and it also has properties which allows it to act as a flocculant, adherent and adsorbent materials[3]. In this work several chitosan sponges with different degree of deacetylation were prepared and tested as possible hemostatic agents for stopping bleeding. The chitosan based hemostatic agents were characterized by X-Ray Diffraction (XRD); Fourier- Transform Infrared Spectroscopy (FT-IR); Scanning and Transmission Electron Microscopy (SEM, TEM) and ¹³C- NMR-MAS. The study of the hemostatic action of the chitosan sponges was done in vitro, using thromboelastographic analyzes, compared to the action of haemostatic agents based on cellulose and zeolites. The main variables studied will be: a) the reaction time to form a clot of approximately 2 mm in size, which characterizes the onset of fibrin production, b) the time of formation of a firm clot of 20 mm and the rate of thrombin generation and the conversion of fibrinogen to fibrin, c) elastic property of formed fibrin and platelet adhesion. [1]R.A.A. Muzzarelli, Chitins and chitosans for the repair of wounded skin, nerve, c a r t i l a g e a n d b o n e , C a r b o h y d r . P o l y m . 7 6 ( 2 0 0 9 ) 1 6 7 – 1 8 2 . doi:10.1016/j.carbpol.2008.11.002; [2]M. Rinaudo, Chitin and chitosan: properties and applications, Prog. Polym. Sci. 31 (2006) 603–632; [3]D. Valle, United States Patent ( 19 ), (1999). (author)