Nanocomposites and nanomaterials

Novel highly dispersed composite hemostatics based on nanosilica and sodium alginate: synthesis and properties 
Guzenko N.V.1, Kravchenko A.A.1, Pakhlov E.M.1, Goncharuk O.V.1, Shtanova L.Ya.2, Yanchuk P.I.2, Tsymbalyuk O.V.2, Komarov I.V.2 Gerashchenko I.I.1
1 Chuiko Institute of Surface Chemistry of the NAS of Ukraine, General Naumov Str. 17, Kyiv 03164, Ukraine. E-mail: guznataliia@gmail.com 
2 Institute of High Technologies, Taras Shevchenko National University of Kyiv, Akademika Hlushkova Avenue, 4, Kyiv 03022, Ukraine

The creation of more effective and safer hemostatic materials than existing ones is very urgent today [1]. The synthesis and properties of highly dispersed composite materials based on nanosilica (A-300; SBET = 295 m2/g) and natural polysaccharide sodium alginate (ANa), which are very promising as haemostatic agents due to their water absorption ability, osmotic properties and sorption activity towards proteins were investigated in the work. The synthesis of SiO2/ANa composites with ANa content from 5 to 20 wt% was carried out by the method of mechanochemical activation (MChA) using water as a solvating agent. The change in the conformation of ANa macromolecules occurs due to interaction with SiO2, resulting in the formation of smaller particles with a different amorphization and contributes to an increase in their bioavailability was shown by IR spectroscopy, XRD, TG-DTA, and SEM methods. The free silanol groups perturbation degree is low and weakly depends on the ANa content in SiO2/ANa composites; so the SiO2 surface remains predominantly available for adsorption interaction with blood plasma proteins, which plays an important role in their activation and blood clotting mechanism. Thus, an insignificant decrease in protein adsorption is observed after the silica modification with ANa (<20 wt% compared to the MChA-treated SiO2) that it was found from the gelatin adsorption isotherms. It was shown that the created SiO2/ANa composites have a pronounced hemostatic effect in the case of parenchymal bleeding from rat liver. Thus, the blood loss was reduced by 77.2%, 79.4% and 69.35% upon use of MChA-treated SiO2 and composites with ANa content of 15 % and 20 wt%, respectively, compared with the control (gauze bandage) during the first 3 min of bleeding. The highest hemostatic activity in 15 min of the experiment was found for composite with ANa content of 15 wt%.

1.	Peng H.T. Hemostatic agents for prehospital hemorrhage control: a narrative review // Mil Med Res.-2020.-7, N 13. P. 1-18.