[Preparation and evaluation of chitosan/alginate microsphere as a novel biodegradable haemostatic powder]

To explore a way to make a new kind of chitosan-based microsphere (MS), which can be used as a novel biodegradable haemostatic powder, and to confirm its haemostatic efficiency.

Chitosan (CTS), a haemostatic polysaccharide, was selected as a main material for the haemostatic powder; alginate (ALG), another haemostatic polysaccharide that has been found to be effective in promoting haemostasis in surgical procedures, was selected to be the costar. The emulsification and the cross-link were chosen as a preparation process based on the interaction between the polysaccharides. The diameter of the prepared MS was determined by SPOS, and the surface of MS was observed under SEM. The swelling characteristics of MS in the simulative wound efflusion were investigated. In a splenic bleeding model in 6 rabbits, MS and Yunnanbaiyao were randomly used as a haemostatic agent, and the corresponding bleeding time was recorded.

The MS prepared in the above-mentioned process was well proportioned and was similarly shaped. It became a kind of white powder after dehydration, and had a coralloid surface under SEM. The diameter of the MS was 4.05+/-2.55 microm, which was determined by SPOS. The swelling ratio of the MS was 280.139% within 5 min. The bleeding time was significantly decreased in the MS treated group (2.83+/-0.17 min) when compared with that in the control group (5.33+/-0.49 min)(P<0.01).

The CTS/ALG-MS, which is made from haemostatic biomaterials (CTS, ALG) by emulsification and the cross-link processes, can be provided with favorable haemostatic efficiency. It can be used as a novel haemostatic powder. However, its biodegrading rate and mode still remain to be further studied.