| Every year, many people die due to excessive hemorrhage, especially in the battlefield.Thus, the development of the hemostatic materials is a research hotspot in the field of biomedicalengineering. As a new hemostatic material, chitosan is used in clinic for its excellent biologicalproperties such as biodegradability, biocompatibility and wound healing activity. Owing to thelimitation of chitosan’s hemostatic effect, the hemostatic functional fillers are usually added.Mesoporous bioactive glass (MBG) has uniform nanoscale mesoporous structure, high specificsurface area and good bioactivity. It could be also used as a hemostatic. However, it isinconvenient to use the MBG as the hemostatic because it is powder. In this paper, a novelcomposite material including mesoporous bioactive glass (M58S) and chitosan (CS) wereprepared by lyophilization technique. Morever, the structure and relative properties of films werestudied. The main research contents and results were listed as follows：1. The preparation of mesoporous bioactive glass M58S and optimization of cross-linker.Firstly, the mesoporous bioactive glass M58S was successfully prepared through one-stepmethod and the structure was characterized by TEM and small angel XRD. The results showedthat M58S had uniform mesoporous structure and the pore size was about5-8nm. Secondly, thevanillin was selected as the cross-linker. The tensile strength of chitosan film was improved withdifferent weight ration between chitoan and vanillin. The tensile strength was the best and thevalue was0.28MPa when the ration was4:1.2. The preparation and study of the M58S/CS composite porous films.Firstly, the surfacemorphology, porous structure of the M58S/CS composite porous films were investigated bySEM、FTIR and XRD. All the films were highly porous with continuous structure ofwell–interconnected pores. The M58S particles were dispersed as islands scattering in thecomposite scaffolds homogenously, and the M58S played little effect on the schiff base reactionbetween CS and vanillin. The interaction between M58S and CS could be found from the XRDresults of M58S and CS. Secondly, the swelling ration, density, water adsorption, porosity andmechanical properties of M58S/CS composite porous films were studied. The effect of M58Scontent on these properties were also discussed, the results had been studied as follows: thewater adsorption and porosity decreased with increasing of M58S content; the swelling propertycould be modulated by varying ratio of M58S and CS; the density of pure chitosan was thesmallest, and the density of the composite films increased with increasing of M58S content. However, the tensile strength decreased.3. The in vitro bioactivity and degradation of the M58S/CS composite porous films. Theresults of in vitro bioactivity and degradation demonstrated that the amount of apatite on thesurface of the composite film increased with increasing of M58S content. The apatite could beformed more efficiently on the composite films than that on the pure chitosan film, implying thatthe bioactivity of composite films was improved by increasing of M58S content. In vitrodegradation behavior indicated that the composite films had good degradability.4. Study of the hemostatic properties based on the animal experiments. Firstly, thehemostatic properties and in vitro cytotoxicity of the composite films were evaluated. The M58S,pure chitosan film and the composite films with different M58S/CS rations had hemostatic effect.Nevertheless, the hemostatic effect had something to do with form of wound dressing and weightration between M58S and CS. The hemostatic effect of porous films was better than the powder.With the increasing of M58S, the hemostatic time and amount of bleeding decreased. Thehemostatic property was the best when the weight percentage of M58S was60%, the hemostatictime was90s and amount of bleeding was0.4±0.02g. The in vitro cytotoxicity of the compositefilms was studied through the observation of cell morphology and MTT assay. The resultsindicated that the composite films had good biocompatibility and were non-cytotoxicity againstL929cell. Secondly, the new hemostasis material was obtained through coating the compositesolution of M58S and CS on the medical gauze and absorbable gelatin sponge. The wounddressing was characterized by SEM、FTIR、TG, and the hemostatic properties of gelatin spongehemostatic material was evaluated. The results showed that the wound dressing had good airpermeability because of its porous structure; the properties of the wound dressings could beimproved for the compatibility M58S, CS and cotton gauze. Increased with the M58S content,the weight loss decreased and the thermal stability improved. The hemostatic effect of gelatinsponge was better when the composite solution of M58S and CS was coated on the gelatinsponge.Above all, the M58S/CS composite porous films prepared by freeze-drying method showeda good morphological structure. The mechanical properties, water adsorption and degradationwere affected by adding M58S, but the bioactivity and hemostatic of the composite filmsimproved. The prepared films were confirmed non-cytotoxicity against L929cell. Theapplication fields of medical gauze and absorbable gelatin sponge were broadened by theincoporation of M58S and CS. Thus, the composite films could be potentially applied as a newwound dressing material. |
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