Despite the continuous improvement in perioperative use of antibiotics and aseptic techniques, the incidence of infection continues to rise as the need for surgery increasing and brings great challenges to orthopedic surgery. The rough or porous structure of the prosthesis provides an excellent place for bacterial adhesion, proliferation and biofilm formation, which is the main cause of infection. Traditional antibiotic therapy and surgical debridement are difficult to determine whether the infected focus have been removed completely and whether the infection will recur. In recent years, nanotechnology has shown obvious advantages in biomaterials and drug delivery. Nano drug carriers can effectively achieve local antimicrobial therapy, prevent surgical infection by local sustained drug release or intelligent controlled drug release under specific stimuli, and reduce the toxic side effects of drugs. The unique advantages of nanotechnology provide new ideas and options for the prevention and treatment of periprosthetic infection. At present, the application of nano-technology in the prevention and treatment of infection can be divided into the addition of nano-drug-loaded materials to prosthesis materials, the construction of drug-loaded nano-coatings on the surface of prosthesis, the perfusable nano-antimicrobial drug carriers, and the stimulation-responsive drug controlled release system. This article reviews the methods of infection prevention and treatment in orthopaedic surgery, especially the research status of nanotechnology in the prevention and treatment of periprosthetic infection.
ObjectiveTo explore the clinical application value of antithrombin Ⅲ (ATⅢ) in pulmonary thromboembolism (PTE).MethodsA retrospective study included 204 patients with confirmed PTE who were admitted to Fujian Provincial Hospital from May 2012 to June 2019. The clinical data of the study included basic conditions, morbilities, laboratory examinations and scoring system within 24 hours after admission. The relationship between ATⅢ and PTE in-hospital death was analyzed, and the value of ATⅢ to optimize risk stratification was explored.ResultsFor ATⅢ, the area under receiver operating characteristic curve (AUC) of predicting in-hospital mortality was 0.719, with a cut-off value of 77.7% (sensitivity 64.71%, specificity 80.21%). The patients were divided into ATⅢ≤77.7% group (n=48) and ATⅢ>77.7% group (n=156) according to the cut-off value, and significant statistically differences were found in chronic heart failure, white blood cells count, platelets count, alanine aminotransferase (ALT), albumin and troponin I (P<0.05). According to the in-hospital mortality, patients were divided into a death group (n=17) and a survival group (n=187), and the differences in count of white blood cells, ATⅢ, D-dimer, ALT, albumin, estimated glomerular filtration rate and APACHEⅡ were statistically significant. Logistic regression analysis revealed that ATⅢ≤77.7% and white blood cells count were independent risk factors for in-hospital death. The risk stratification and the risk stratification combined ATⅢ to predict in-hospital death were evaluated by receiver operating characteristic curve, and the AUC was 0.705 and 0.813, respectively (P<0.05). A new scoring model of risk stratification combined with ATⅢ was showed by nomogram.ConclusionsATⅢ≤77.7% is an independent risk factor for in-hospital death, and is beneficial to optimize risk stratification. The mechanism may be related to thrombosis, right ventricular dysfunction and inflammatory response.
Objective To investigate the physicochemical properties of pure titanium surface grafted with chlorhexidine (CHX) by phenolamine coating, and to evaluate its antibacterial activity and osteoblast-compatibility in vitro. MethodsControl group was obtained by alkali and thermal treatment, and then immersed in the mixture of epigallocatechin-3-gallate/hexamethylene diamine (coating group). Phenolamine coating was deposited on the surface, and then it was immersed in CHX solution to obtain the grafted surface of CHX (grafting group). The surface morphology was observed by scanning electron microscope, the surface element composition was analyzed by X-ray photoelectron spectroscopy, and the surface hydrophilicity was measured by water contact angle test. Live/dead bacterial staining, nephelometery, and inhibition zone method were executed to evaluate the antibacterial property. Cytotoxicity was evaluated by MTT assay and cell fluorescence staining. Bacteria-MC3T3-E1 cells co‐culture was conducted to evaluate the cell viability on the samples under the circumstance with bacteria. Results Scanning electron microscope observation results showed that deposits of coating group and grafting group increased successively and gradually covered the porous structure. X-ray photoelectron spectroscopy results showed the peak of N1s enhanced and the peak of Cl2p appeared in grafting group. Water contact angle test results showed that the hydrophilic angle of three groups increased in turn, and there was significant difference between groups (P<0.05). Live/dead bacteria staining results showed that the grafting group had the least amount of bacteria adhered to the surface and the proportion of dead bacteria was high. The grafting group had a transparent inhibition zone around it and the absorbance (A) value did not increase, showing significant difference when compared with control group and coating group (P<0.05). MTT assay and cell fluorescence staining results showed that the number of adherent cells on the surface of the grafting group was the least, but the adherent cells had good proliferation activity. Bacteria-cell co-culture results showed that there was no bacteria on the surface of grafting group but live cells adhered well. ConclusionCHX-grafted phenolamine coating has the ability to inhibit bacterial adhesion and proliferation, and effectively protect cell adhesion and proliferation in a bacterial environment.