[The hemostasis effect and cell compatibility of a chitosan-calcium alginate-laponite nanosheet composite membrane: in vitro and in vivo evaluation].

PURPOSE: To explore the feasibility of a chitosan-calcium alginate-laponite nanosheet composite membrane being used as a new hemostatic membrane for wounds in oral cavity. METHODS: The composite membrane was prepared in a layered fashion: the lower layer of chitosan membrane was made through self-evaporation and the upper layer of calcium alginate-laponite nanosheet sponge was made via freeze-drying. The microstructure of the composite membrane was observed under scanning electron microscopy (SEM) and transmission electron microscopy (TEM). X-ray diffraction was used as a means of identifying the compounds. Clotting time of composite membrane, medical gauze and Chitin dressing in vitro was measured by the plate method for blood coagulation. Cytotoxicity tests were quantified through co-culturing NIH/3T3 cells with chitosan-calcium alginate extract, composite hemostatic membrane extract and DMEM. Superficial buccal mucosal wound models and tooth extraction models were created on beagles dogs, the hemostatic effect and adhesion to oral mucosa were evaluated on these models. Statistical analysis was performed using SPSS 18.0 software package. RESULTS: The composite hemostatic membrane consisted of double-layer in microstructure, the upper layer was a foam layer consisting of calcium alginate and laponite nanosheet, the substratum was formed by uniform chitosan film. X-ray diffraction results showed that laponite nanosheet can be found in the composite membrane. Coagulation test showed that the composite hemostatic membrane group significantly shortened clotting time in vitro compared to pure calcium alginate group, commercial hemostatic membrane and blank control group(P＜0.001). CCK-8 test of NIH/3T3 cell showed that there was no significant difference in absorbance between the experimental group, negative control group and blank control group (P＞0.05). In addition, composite hemostatic membrane displayed a good hemostatic effect and strong adhesion to oral mucosa in animal models. CONCLUSIONS: The composite hemostatic membrane showed great hemostatic effects and had no significant cytotoxicity, which has the potential for clinical application as hemostatic membrane for wounds in oral cavity.