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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.
Subject(s)
Chitosan , Silver Nitrate , Titanium , Anti-Bacterial Agents/pharmacology , Coloring AgentsABSTRACT
Objective:To investigate the antibacterial and osteogenic properties of biomimetic mineralized iodine-loaded coating with micro-nano topography on the surface of bone implants.Methods:After the fiber network structure of sodium hydrogen titanate was constructed by alkali thermal reaction on the surface of Ti6Al4V (noted as AT), it was biomimetically mineralized in the modified simulated body fluid to form a micro-nano topology with high specific surface area (noted as AT-CaP), and finally loaded with PVPI to construct a novel antibacterial osseointegration coating (noted as AT-CaP-PVPI). The study was conducted in AT, AT-CaP, and AT-CaP-PVPI groups, in each of which 3 parallel experiments were performed. The morphology and colony counting of Staphylococcus aureus on the coating surface were observed to detect the in vitro antibacterial performance of the coating. Fifteen male SD rats were randomly divided into 3 groups ( n=5): AT, AT-CaP, and AT-CaP-PVPI. After intramedullary injection of Staphylococcus aureus into the lower end of the femur in the SD rats, titanium rods coated with AT, AT-CaP, and AT-CaP-PVPI were inserted into the marrow cavity. The osteogenesis, volume ratio of new bone mass and number of trabeculae on the surface of the femoral implants were compared between the 3 groups 4 weeks after operation. Results:In AT and AT-CaP groups, a large number of bacteria grew in their inherent elliptical or spherical shape on the implant surface and a large number of colonies were seen on the plate; in AT-CaP-PVPI group, the bacteria on the coating surface exhibited membrane deformation and depression, some of them were completely broken and dissolved, and a large number died. There was almost no new bone formation around the implants in AT group; new bone scattered around the implants with discontinuous distribution in AT-CaP group; a great amount of new bone was seen around the implants with even distribution but no signs of infection in AT-CaP-PVPI group. The volume ratio of new bone mass and the number of trabeculae on the implant surface in AT-CaP-PVPI group were 0.453±0.206 and 6.055±0.536, respectively, significantly higher than those in AT group (0.046±0.028 and 1.667±1.249) and AT-CaP group (0.188±0.052 and 3.804±0.889) ( P<0.05). Conclusion:Biomimetic mineralized iodine-loaded coating with micro-nano topography on the surface of bone implants shows good antibacterial and osteogenic properties.
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Objective: The antibacterial properties of porous medical implant materials were reviewed to provide guidance for further improvement of new medical implant materials. Methods: The literature related to the antibacterial properties of porous medical implant materials in recent years was consulted, and the classification, characteristics and applications, and antibacterial methods of porous medical implant materials were reviewed. Results: Porous medical implant materials can be classified according to surface pore size, preparation process, degree of degradation in vivo, and material source. It is widely used in the medical field due to its good biocompatibility and biomechanical properties. Nevertheless, the antibacterial properties of porous medical implant materials themselves are not obvious, and their antibacterial properties need to be improved through structural modification, overall modification, and coating modification. Conclusion: At present, coating modification as the mainstream modification method for improving the antibacterial properties of porous medical materials is still a research hotspot. The introduction of new antibacterial substances provides a new perspective for the development of new coated porous medical implant materials, so that the porous medical implant materials have a more reliable antibacterial effect while taking into account biocompatibility.
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Objective To study the antibacterial property of silver loaded titanium dioxide (TiO2) antibacterial coated endotracheal intubation tube,and to determine the minimum effective antibacterial concentration.Methods Intubation tubes coated with different concentrations of antibacterial agents were prepared with sol gel method.Polyethylene endotracheal intubation tubes were used as substrate,and silver loaded TiO2 was used as the antibacterial agent.According to the different antibacterial concentrations of the antibacterial agent,the tubes were divided into nine groups:10.0％ group,5.0％ group,2.0％ group,1.5％ group,1.0％ group,0.8％ group,0.6％ group,0.2％ group,and conrol group.They were respectively immersed in three standard bacteria suspensions with 1.0 × l05 cfu/mL:Pseudomonas aeruginosa,Staphylococcus aureus,and Escherichia coll Together with standard bacteria liquid group,there were 10 experimental groups.They were kept overnight for 24 hours.10 μL of respective culture medium was smeared on blood agar culture medium.After being cultured overnight in 35 ℃,the number of bacteria colonies was respectively counted.Results In 1.0 × 105 cfu/mL of three standard bacteria liquids with antibacterial agent concentration≥ 1.0％,three bacterial colonies had un-obviously growth rate.Almost the same strong antibacterial effects to achieve sterilizing rates of more than 98％ was shown in each group of the antibacterial coating endotracheal intubation tubes (all P＞0.05).As the antibacterial agent concentration decreased,three bacterial colonies were increasing gradually.Intermediate antibacterial effects were shown in tubes of 0.8％ group,with significant statistic difference as compared with 1.0％ and 0.6％ groups [Pseudomonas aeruginosa:7.300 (4.050,8.350) vs.0.200 (0.050,1.200),9.700 (9.000,10.000); Staphylococcus aureus:4.100 (3.300,4.650) vs.0.000 (0.000,0.150),5.800 (5.350,7.650); Escherichia coli:1.400 (0.750,3.750) vs.0.050 (0.025,0.050),9.500 (8.500,9.800),all P＜0.01].Conclusions Silver loaded TiO2 antibacterial coated endotracheal intubation tube had definite antibacterial properties,which were related to the antibacterial concentration.Strong antibacterial effects were shown when antibacterial concentration was above 1.0％,with bacteria almost completely killed in the immersing liquid.