| BackgroundsAlong with social economy development, the injure between bone and joint and the demand of the metallic implant materials increase year by year, cause by industrial production, traffic accident and sports. And more and more patients have an operation; include plate internal fixation, orthopedics, and artificial joint replacement, which are cause osteoarthrosis, trauma and spinal diseases. Even in the strict aseptic operation and in the systemic use of the treatment of antibiotics to prevent infection, there it can be orthopaedic infection. Once the infection appeared, that may lead to the failure of operation, and will have a limb dysfunction, low the living quality, and increase the medical cost. Therefore finding the way for prevention of postoperative infection is very important.In the basic medicine study, Titanium and Ti alloy have excellent biocompatibility, biomechanical property, corrosion resistance, promotes the regeneration of the cells and growth of the bone. Now it’s the most popular metallic material in clinic and the experimental research. It has been widely used in the orthopedics of artificial joint prosthesis, artificial vertebral body, catagmatic internal fixation and bone screw, and in the dental clinic of dental implants. Titanium and Ti alloy implants still face some problem like high biologically inert, poor biological activity and lack of antibacterial properties, which might easily lead to complications such as early loosening and infection. How to improve the biological activity of the material surface, so that both promote osseointegration but inhibition of bacterial adhesion to a certain extent, thereby reducing the risk of infection and loosening, become hot and difficult the current artificial joints and other titanium-based implant study.With the continuous development of nanotechnology, nano-antibacterial material is a new material, which is having antibacterial function. The antimicrobial properties of the antibacterial agent and working live increase, is due to the high specific surface area and highly reactive in the nano-antibacterial material. Nanometer Ag antimicrobial material combines with the dual advantage of the inorganic antibacterial material and the nano-antibacterial material. It regarded as the strongest nanometer antibacterial agents. Institute of Industry and Chemical Technology of Guangdong University of Technology carried out the research, the specimens with nanopit surfaces were prepared by the chemical etching modification, creating an excellent rough surface with suitable topography and roughness on a machined titanium surface. Further, a bioinspired PDA layer was deposited on nanotextured titanium surface by simply dipping the substrate into an alkaline dopamine solution, which is with structure of imitation of mussel protein. On the other hands, using the functional groups of ortho phenolic hydroxyl and benzoquinonyl in the PDA layer, to grow a new polydopamine assisted decoration of porous titanium surface with silver nanoparticles. However, the specific biological properties are still unclear.Then in the basic medicine study, except improving the in-plant metal materials, now having the other effective methods for preventing infection after the curettage or not, it needs the further investigation from two parts:one is intraoperative improvement; the other is postoperative management.Objectives1.Bionic PDA layer was constructed by dopamine polymerize on the surface of nanoporous titanium, which is with the good bioactivity. Then it relied on the chelate effect and the reducibility of PDA, by adjusting the reaction time of the silver nanoparticles load into polydopamine modified titanium surface, to get the different concentration of the silver nanoparticles of polydopamine decoration titanium. The different concentration of the silver nanoparticles of polydopamine modified titanium are tested the compatibility and antibacterial of the in-vitro biological by using SEM, cell adhesion, cytotoxicity and the sterilization rate for the reference on clinical application of animal experiments.2.To do a statistical analysis for the case of the artificial femoral head replacement operation and the foot and ankle fracture operation by the Affiliated Jiangmen People’s Hospital of Southern Medical University. To evaluate the reducing bleeding efficacy of bio-polysaccharide washing colloidal solution in artificial femoral head replacement.MethodsPart Ⅰ:Basic medical research---Preparation of poly dopamine modified cribrate Ti containing silver nanoparticles (Ti-PDA-Ag) and the research of its biological properties.Bassed on making use of the chemical etching technique, Bionic PDA layer was constructed by dopamine polymerize on the surface of nanoporous titanium, then it relied on the chelate effect and the reducibility of PDA, By adjusting the reaction time of the silver nanoparticles load into polydopamine decoration of titanium surface, to get the different samples of PDA/nano-silver modified titanium with silver nanoparticles with different concentration of the silver nanoparticles (Ti-PDA-Ag-15min,Ti-PDA-Ag-30min,Ti-PDA-Ag-60min). Cell experiments were carried out and divided into three groups, which were nTi group, Ti-PDA group, and PDA/polydopamine modified titanium with silver nanoparticles with different concentration of the silver nanoparticles(Ti-PDA-Ag-15min, Ti-PDA-Ag-30min, Ti-PDA-Ag-60min). The features of titanium surface were examined using scanning electron microscope (SEM). Murine preosteoblast was cultured on different titanium surfaces. Adhesion of the cell surface was observed form cell under the scanning mirror the adherence, proliferation, differentiation and mineralization were observed by 4’,6-diamidino-2-phenylindole (DAPI) assay. Staphylococcus aureus and staphylococcus epidermidis was chosen to investigate bacteria adhesion on different surfaces using ultrasound separation quantitatively counting after co-culture with specimens.Part II:Clinical medical research:(1) The application of biological polysaccharide washing glue solution in artificial thigh bone replacement.There were two groups optionally divide from 48 cases of artificial femoral head replacement, one group is using of biological polysaccharide washing glue solution, the other one is using of the physiological saline to treat the wound. To make the contrast and the study for the bad conditions between two groups, which is the age, preoperative Hb, HCT, PLT, PT, TT and peri-operative bleeding.(2) Clinical research of vacuum sealing drainage on the prevention of wound infection after ankle fracture fixation.There were 43 cases of foot closed fracture optionally divide into observation group and control groups, that the postoperative incision treated by vacuum sealing drainage in the observation group, and it treated by the conventional way in the control groups. To make the contrast and the study on AOFAS scores after observation the time from wound to operation after fracture, healing time of the wound, occurrence of complications after surgery, and the fracture healing.Result1. Preparation of polydopamine modified cribrate Ti containing silver nanoparticles (Ti-PDA-Ag) and the research of its biological properties.Selected rice preosteoblasts(MC3T3-E1 cells) as study subjects, and observed the cytobiological effects like cell adhesion and proliferation of pure Ti group(Ti group), nano Ti group(nTi group), PDA modified cribrate Ti group(Ti-PDA group) and PDA/nano silver modified cribrate Ti groups with different silver nanoparticle concentrations(Ti-PDA-Ag-15min,Ti-PDA-Ag-30min,Ti-PDA-Ag-60min). It’s been found out that the cell number of 120min early adhesion in Ti-PDA group, Ti-PDA-Ag-15min group, Ti-PDA-Ag-30min group and Ti-PDA-Ag-60min group was significantly increased than that in Ti group and nTi group, and there was statistical significance for the difference (P< 0.05).Observation of scan images indicated that Ti-PDA group; Ti-PDA-Ag-15min group, Ti-PDA-Ag-30min group and Ti-PDA-Ag-60min group had larger number and better adhesion status of MC3T3-E1 cells than that in Ti group and nTi group. As for proliferation ability, after cultured on the material for 1 day and 3 days, there was no significant difference among all groups in the number of MC3T3-E1 cells; till cultured for 5 days and 7 days, there was no significant difference between Ti, nTi and Ti-PDA group, while Ti-PDA-Ag-15min group and Ti-PDA-Ag-30min had shown certain inhibition effect on the proliferation of MC3T3-E1 cells, the proliferation rate was still larger than 90%, but for Ti-PDA-Ag-60min group, the proliferation rate had been decreased significantly to 80%, which had shown relatively high cytotoxicity comparing with Ti-PDA-Ag-15min group and Ti-PDA-Ag-30min group, the difference had significance(P<0.01).Selected staphylococcus aureus and E.coli as study subjects, and observed the sterilizing rate of nano Ti group(nTi group), PDA modified cribrate Ti group(Ti-PDA group) and PDA/nano silver modified cribrate Ti groups with different silver nanoparticle concentrations(Ti-PDA-Ag-15min,Ti-PDA-Ag-30min,Ti-PDA-Ag-60min), and took pure Ti group(Ti group) as the control group. When treated with co-culture method, it’s been noticed that the sterilizing rates to group staphylococcus aureus of Ti-PDA-Ag-15min group,Ti-PDA-Ag-30min group and Ti-PDA-Ag-60min were 60.4%,100% and 100% respectively, and the sterilizing rates to E.coli were 83.8%,100% and 100% respectively.2. The application of biological polysaccharide washing glue solution in artificial thigh bone replacement.The total postoperative drainage volume of observation group was (243.70±112.17)ml, while the total postoperative drainage volume of control group was (382.68±130.20)ml, there was significant difference in postoperative drainage volume between two groups(P<0.01); the postoperative transfusion rate of observation group was 2%, while the postoperative transfusion rate of control group was 32%, there was significant difference in postoperative transfusion rate between two groups(P<0.05); There was no significant difference between two groups in age, preoperative Hb, HCT, PLT, PT, TT and peri-operative bleeding(P>0.05).3. Clinical research of vacuum sealing drainage on the prevention of wound infection after ankle fracture fixation.There was no statistical significance between observation group and control group in gender, age and the time from wound to operation(P>0.05); Observation group was better than control group in side effect rate, healing time, AOFAS scores(P<0.05).Conclusion1. Traditional metallic implant materials have good biological compatibility, comprehensive mechanics properties and anti-erosion ability in biological environment, which has been clinically used largely and extensively. However, infection and loosing of implant materials are two main failed reasons. As traditional metallic implant materials, medical titanium has good biological compatibility, biological mechanics properties and anti-erosion ability. It also has advantages like low relative density, high mechanical strength and elasticity more close to human bone, which is now clinically used extensively. If introducing bionic modification and antibacterial coating, its value would be greatly enhanced.2. Loading the silver nanoparticles to titanium surface by holing titanium surface with nanotechnology and using deoxidization of PDA, the PDA/nano-silver modified titanium surface has good cellular adhesion and has strong sterilization toward staphylococcus aureus and Escherichia coli.3. Silver ions have cytotoxicity in some extent, and by adjusting precipitation reaction time of nano-silver, the amount of silver ions releasing from materials surface could be adjusted. In this case, PDA/nano-silver modified titanium materials would have low cytotoxicity and strong antibacterial ability.4. Biological polysaccharide washing glue solution can be biological barrier. It can prevent tissue from adhesions with each other and protect tissue’s biological activity at the same time, reducing leakage, easing stimulus, and promoting full repair of epithelial and tissue wound. It can also remove bloodstain and bacteria on tissue wound effectively and transform into protecting film in rinsing area, which would be able to reduce leakage, fully prevent adhesions and resist bacteria. Using biological polysaccharide rinse glue in the artificial femoral head replacement can prevent postoperative infection effectively.5.The vacuum sealing drainage is a method to treat wound that is hard to heal. It drains sufficiently and timely and smoothly, promoting partial blood circulation in draining area, reducing partial tissue’s edema, promoting growth of partial artery, maintaining moisture of the wound, sealing up the wound to lower the chance of contamination. After the ankle fracture fixation, using the vacuum sealing drainage for the wound can effectively avoid postoperative infection, lower the chance of fracture fixation failure, relieve patients of long suffering and economic burden because of wound infection, improve bone healing rate and patient’s ankle function, ease patient’s pain and medical workers’ burden. It is a good method to prevent wound infection.6. Aseptic operation is the most important in the methods for preventing orthopedic infections. |
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