Titanium alloy has good biological properties and is commonly used in orthopedics, but its bone integrity and antibacterial properties are poor, so surface modification is needed to make up for its shortcomings. Chitosan has good biocompatibility and film forming ability, and can be used as a carrier to introduce the target drug to the surface of titanium alloy, which can effectively improve the biological properties of titanium alloy materials and increase its application range. In this paper, the related research of chitosan surface modified titanium alloy materials in recent years is summarized. The modification methods of chitosan coating, the improvement of osteogenesisand antibacterial properties of titanium alloy materials are discussed in order to provide guidance for the clinical application of coating modification of titanium alloy materials.
Alloys ; Anti-Bacterial Agents/pharmacology* ; Chitosan ; Orthopedics ; Surface Properties ; Titanium

Whether in war or peace, timely, effective and accurate hemostasis is an important measure to improve the survival rate and cure rate of the wounded. All the countries in the world are actively developing different types of hemostatic materials so as to reduce the amount of bleeding in an emergency and create favorable conditions for subsequent transport and treatment. At present, the commercialized hemostatic materials are mainly divided into natural biological, synthetic biological, mineral and coagulation components, but all these materials have their own limitations. In this article, the characteristics of chitosan and its derivatives are reviewed as the representatives of the natural organic macromolecular polysaccharide hemostasis materials. Their molecular structures, biomedical properties, domestic and foreign research and application progress as well as comparison with applications of other hemostatic materials are involved. The further research is prospected for optimization and innovation to develop composite chitosan hemostatic materials with the function of hemostasis, antibiosis, pain relief and promoting wound healing.
Blood Coagulation ; Chitosan/pharmacology* ; Hemorrhage ; Hemostasis ; Hemostatics ; Humans

Effective haemostatic materials can quickly control bleeding and achieve the purpose of saving patients' lives. In recent years, chitosan-based haemostatic materials have shown good haemostatic effects, but their application is limited because chitosan is almost insoluble in water. Carboxymethyl chitosan-based haemostatic materials can promote hemostasis by activating red blood cells and aggregating platelets. In addition, carboxymethyl chitosan can bind with Ca²⁺ to activate platelets and coagulation factors, and start endogenous coagulation pathways, which can adsorb fibrinogen in plasma to promote haemostasis. In this paper, the latest research progress of carboxymethyl chitosan-based haemostatic materials and their haemostatic mechanism were reviewed, in order to further strengthen the understanding of the haemostatic mechanism of carboxymethyl chitosan-based haemostatic materials, and provide new idea for the research and clinical application of carboxymethyl chitosan-based haemostatic materials.
Humans ; Hemostatics ; Chitosan/pharmacology* ; Hemostasis ; Blood Coagulation/physiology* ; Hemorrhage

OBJECTIVE: To characterize the silver in chitosan antibacterial gel, and to establish a method for the determination of silver content in samples. METHODS: The silver in the samples was analysed by scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and single particle inductively coupled plasma mass spectrometry (SP-ICP-MS). Microwave digestion was adopted to digest the chitosan antibacterial gel, and then the content of silver was determined by flame atomic absorption spectrometry. RESULTS: The analysises showed that the particle size of silver in chitosan antibacterial gel was about 150~ 200 nm. The silver showed good linearity in the concentration range of 25~250 μg/L (y=0.000 35x+0.001 7, r=0.999 9). The recovery rate (n=9) was 98.5%. CONCLUSIONS SEM, EDS and SP-ICP-MS can be used for the characterization of silver particles in chitosan antibacterial gel. Microwave digestion-flame atomic absorption spectrophotometry method is simple, practicable, high precision and high quantitative accuracy, which is suitable for the quantitative analysis of silver in chitosan antibacterial gel.
Anti-Bacterial Agents/pharmacology* ; Chitosan/chemistry* ; Microwaves ; Particle Size ; Silver

OBJECTIVE: To design and construct a graphene oxide (GO)/silver nitrate (Ag₃PO₄)/chitosan (CS) composite coating for rapidly killing bacteria and preventing postoperative infection in implant surgery. METHODS: GO/Ag₃PO₄ composites were prepared by ion exchange method, and CS and GO/Ag₃PO₄ composites were deposited on medical titanium (Ti) sheets successively. The morphology, physical image, photothermal and photocatalytic ability, antibacterial ability, and adhesion to the matrix of the materials were characterized. RESULTS: The GO/Ag₃PO₄ composites were successfully prepared by ion exchange method and the heterogeneous structure of GO/Ag₃PO₄ was proved by morphology phase test. The heterogeneous structure formed by Ag₃PO₄ and GO reduced the band gap from 1.79 eV to 1.39 eV which could be excited by 808 nm near-infrared light. The photothermal and photocatalytic experiments proved that the GO/Ag₃PO₄/CS coating had excellent photothermal and photodynamic properties. In vitro antibacterial experiments showed that the antibacterial rate of the GO/Ag₃PO₄/CS composite coating against Staphylococcus aureus reached 99.81% after 20 minutes irradiation with 808 nm near-infrared light. At the same time, the composite coating had excellent light stability, which could provide stable and sustained antibacterial effect. CONCLUSION GO/Ag₃PO₄/CS coating can be excited by 808 nm near infrared light to produce reactive oxygen species, which has excellent antibacterial activity under light.
Chitosan ; Silver Nitrate ; Titanium ; Anti-Bacterial Agents/pharmacology* ; Coloring Agents

In this experiment, Panax notoginseng saponins chitosan nanoparticles(PNS-NPs) were prepared by self-assembly and their appearance, particle size, encapsulation efficiency, drug loading, polydispersity index(PDI), Zeta potential, and microstructure were characterized. The prepared PNS-NPs were intact in structure, with an average particle size of(209±0.258) nm, encapsulation efficiency of 42.34%±0.28%, a drug loading of 37.63%±0.85%, and a Zeta potential of(39.8±3.122) mV. The intestinal absorption of PNS-NPs in rats was further studied. The established HPLC method of PNS was employed to investigate the effects of pH, perfusion rate, and different drugs(PNS raw materials, Xuesaitong Capsules, and PNS-NPs). The absorption rate constant(K_a) and apparent permeability coefficient(P_(app)) in the duodenum, jejunum, ileum, and colon were calculated and analyzed. As illustrated by the results, the intestinal absorption of PNS-NPs was increased in the perfusion solution at pH 6.8(P<0.05), and perfusion rate had no significant effect on the K_a and P_(app) of PNS-NPs. The intestinal absorption of PNS-NPs was significantly different from that of PNS raw materials and Xuesaitong Capsules(P<0.05), and the intestinal absorption of PNS-NPs was significantly improved.
Animals ; Chitosan/pharmacology* ; Intestinal Absorption ; Nanoparticles ; Panax notoginseng/chemistry* ; Rats ; Saponins/pharmacology*

OBJECTIVE: A dynamic gel loaded with lyophilized platelet-rich plasma-chitosan/difunctionalized polyethylene glycol (LPRP-CP) was prepared to investigate its hemostatic antibacterial and promoting wound healing of scald wounds through in vitro and in vivo experiments. METHODS: In this study, normal gauze/blank tablet (Ctrl), LPRP-CP, Chitosan HUCHUANG Powder(Chito P)and ChitoGauze XP PRO group (Chito G group) were set. The hemostatic effect and promoting healing effect of the four groups of materials were evaluated by establishing rabbit ear artery hemorrhage model and superficial Ⅱ° scalded model of skin on the back. The hemostatic time and bleeding amount were calculated and the gross and histological results of scald healing were observed. The antibacterial effect of the four groups of materials was evaluated by antibacterial test in vitro. RESULTS: In the rabbit ear arterial hemorrhage model, the hemostasis of all materials was successful. The hemostatic time of Ctrl, Chito P, LPRP-CP and Chito G groups was 213.33±38.30, 118.33±24.01, 115.00±8.37 and 111.67±11.69 s, respectively. The blood loss was 1233.83±992.27, 346.67±176.00, 193.33±121.47 and 147.50±80.66 mg, respectively. Compared with Ctrl, the hemostasis time of LPRP-CP, Chito P and Chito G group was significantly shorter (P<0.001), and the amount of blood loss of LPRP-CP and Chito G group was decreased (P<0.05). Compared with LPRP-CP, there were no significant differences in hemostatic time and blood loss between Chito P and Chito G group (P>0.05). In the model of superficial Ⅱ° scalded on the back of rabbit, the wound healing rate of LPRP-CP was faster than that of the other three groups at the same time, and the healing effect was perfect. In the antibacterial test in vitro, only LPRP-CP had better anti-S. aureus effect, and all groups had no anti-E. coli effect. CONCLUSION LPRP-CP is an excellent hemostatic material for superficial wounds, and has certain antibacterial and wound healing effects, which has a wide academic value and research prospects.
Animals ; Anti-Bacterial Agents/pharmacology* ; Chitosan/pharmacology* ; Hemorrhage ; Hemostasis ; Hemostatics ; Humans ; Platelet-Rich Plasma ; Rabbits

The biofilms formed by pathogenic microorganisms seriously threaten human health and significantly enhance drug resistance, which urgently call for developing drugs specifically targeting on biofilms. Chitooligosaccharides extracted from shrimp and crab shells are natural alkaline oligosaccharides with excellent antibacterial effects. Nevertheless, their inhibition efficacy on biofilms still needs to be improved. Spirulina (SP) is a microalga with negatively charged surface, and its spiral structure facilitates colonization in the depth of the biofilm. Therefore, the complex of Spirulina and chitooligosaccharides may play a synergistic role in killing pathogens in the depth of biofilm. This research first screened chitooligosaccharides with significant bactericidal effects. Subsequently, Spirulina@Chitooligosaccharides (SP@COS complex was prepared by combining chitooligosaccharides with Spirulina through electrostatic adsorption. The binding of the complex was characterized by zeta potential, z-average size, and fluorescence labeling. Ultraviolet-visible spectroscopy (UV-Vis) showed the encapsulation efficiency and the drug loading efficiency reached up to 90% and 16%, respectively. The prepared SP@COS2 exhibited a profound synergistic inhibition effect on bacterial and fungal biofilms, which was mainly achieved by destroying the cell structure of the biofilm. These results demonstrate the potential of Spirulina-chitooligosaccharides complex as a biofilm inhibitor and provide a new idea for addressing the harm of pathogenic microorganisms.
Humans ; Spirulina ; Anti-Bacterial Agents/chemistry* ; Chitosan/pharmacology* ; Biofilms ; Chitin/pharmacology*

OBJECTIVETo observe the effect of the self-made chitosan thermosensitive hydrogel system with dual-release bone morphogenetic protein and chlorhexidine on periodontal defects repair.

METHODSThe furcation defect model was established on dog premolar. The models were divided into five groups, including three experimental groups, one control group and one blank control group. The hydrogel with the chlorhexidine/3-cyclodextrin inclusion complexes (IC) /rhBMP-2, hydrogel with rhBMP-2, hydrogel with IC, the pure hydrogel were applied to the defects of the four groups, respectively, and the blank control group did not receive any agent. The dogs were sacrificed 8 weeks later and the periodontal regeneration and gingival condition were observed by histological examination.

RESULTSObvious periodontal tissue regeneration was found in group one and two. The heights of new bone reached 99.2% of the defects in group one, 87.8%, 63.6%, 37.0% and 34.3% in group two, three, four and blank control groups, respectively. The inflammation of the affected gingiva showed less significant in group one and group three than in the other groups.

CONCLUSIONSrhBMP-2 and chlorhexidine played their independent role in repairing periodontal defects and the dual-release chitosan thermosensitive hydrogel system is effective and convenient to use.

Animals ; Bone Morphogenetic Proteins ; pharmacology ; Chitosan ; pharmacology ; Chlorhexidine ; pharmacology ; Dogs ; Hydrogels ; pharmacology ; Male ; Periodontium ; drug effects ; physiology ; Regeneration ; Tissue Engineering

OBJECTIVETo assess the effect of cyclosporine A (CsA) loaded in chitosan conduit on bridging the sciatic nerve defects in a rat model.

METHODSA 10 mm sciatic nerve defect was bridged using a chitosan conduit filled with 10 μl carrier-drug dilution (10 μg/L CsA). In control group, the conduit was filled with the same volume of carrier dilution alone. The regene-rated fibers were studied 4, 8 and 12 weeks after surgery.

RESULTSThe functional study confirmed faster recovery of the regenerated axons in treatment group than control group (P<0.05). There was statistically significant difference of the gastrocnemius muscle weight ratios between treatment and control groups (P<0.05). Morphometric indices of regenerated fibers showed that the number and diameter of the myelinated fibers in CsA-treated animals were significantly higher than those in control group. In immunohistochemistry, the location of reactions to S-100 in CsA group was clearly more positive than control group.

CONCLUSIONCsA loaded in a chitosan conduit results in improvement of functional recovery and quantitative morphometric indices of sciatic nerve. It is easily available without any complications compared with its systemic administration.

Animals ; Chitosan ; Cyclosporine ; administration & dosage ; pharmacology ; Immunohistochemistry ; Nerve Regeneration ; drug effects ; Rats ; Sciatic Nerve ; chemistry ; injuries