Evaluation of hemostatic behavior of micro and nano gelatin/silica hybrid in severe bleeding.

The pH variation of the injury site is an important factor in the failure of styptic and its structural damage. In this study, the behaviour of a gelatin-silica hybrid in severe bleeding was evaluated under different pH values. On the other hand, the effect of the hybrid particle size, which is one of the key physical properties of the hybrid, has been studied in rapid control of haemostasis. The hybrid haemostatic behaviour varied drastically by changing the particle size, so that the hybrid containing SiO2 with the average particle size of about 1 micro-meter (Hyb Gel-MSiO2) demonstrated very poor ability in platelet adhesion in neutral pH, about 24%. Also, the aPTT was not shorter than the normal time, whereas reduction of the particle size beyond a certain limit (with nano-meter SiO2 for Hyb Gel-NSiO2) led to both increasing platelet adhesion to 32% and very considerable reduction of aPTT. Alignment of all results showed that the particle size reduction improves the haemostatic behaviour of the hybrid toward its best performance by controlling excessive bleeding. By changing the pH for a certain particle size, structural integrity, and thereby the hybrid haemostatic behaviour changed dramatically. Therefore, the nano-hybrid showed the most blood absorption (around 470%) in natural pH and acceded to a coherent structure. The results demonstrated that in alkaline or acidic environment, the hybrid haemostatic behaviour was limited. Based on the results of this study, it was found that changes in the hybrid behaviour in acidic pH were much more drastic than in alkaline pH, and also the hybrid with the optimum particle size (Hyb Gel-NSiO2) can maintain the structural integrity with rapid haemostasis (<3 seconds). Based on the objective that the pH at the injury site change to the alkaline side, the resulting hybrid has an excellent ability to control excessive bleeding and can be proposed for further in vivo studies as a novel styptic.