Bone Cement Loading With Triclosan In Vitro: The Antibacterial Activity And Biomechanical Properties

Objective:This study selected one import bone cement without antibiotic activity, Experiment with the powder characteristics of triclosan and gentamicin sulfate antibiotic substances, Three common bacteria infections, staphylococcus aureus, escherichia coli, staphylococcus epidermidis. Respectively, mixing bone cement for different doses of triclosan and gentamicin. Made of tablet of antibacterial activity bone cement. put into three kinds common infectious bacteria culture dish:①to coMPare the diameter of inhibition zone of different time points, Created the drug release law of antibacterial activity of triclosan cement change over time in vitro.②made in accordance with international standards of different doses of bone cement module. By biomechanical stress and elastic modulus tests, Antibacterial activity were coMPared the biomechanical properties of bone cement.Methods:The experiment was conducted in the Orthopaedic Laboratory and Clinical Microbiology Division of People's Liberation Army General Hospital between 2009-2/2009-10.①Preparation of antibacterial tablets:To triclosan, gentamicin were weighing out 0.5g, 1.0g,1.5g,2.0g and 40g doses of bone cement mixed in sterile conditions, Adding 15mL of sterile liquid ampoule,2min after mixing, adding among the shaping mold, Diameter made of 6mm, the thickness of 3mm of the short cylinder,6 for each dose. Mold is made from high density polyethylene.②preparation of the model of measurement of biomechanical properties:A: determination of compressive strength of bone cement modules:gentamicin sulfate and Triclosan of different doses mixed with cement poured into the cylinder (the length 12mm±0.1mm, diameter 6mm±0.1mm), At 23℃ambient temperature, the preservation of bone cement cylinder. B:Determination of flexural strength of bone cement modules:Mold is made from high density polyethylene, Each mold has a mold trough, about 75mm, width 10mm, depth 3.3mm, a total of six.③inhibition experiments with measured:triclosan and gentamicin sulfate of the different doses (0.5g, 1.0g,1.5g,2.0g) mixed with bone cement, respectively, each made of six specimens, put into three experimental strains, each culture dish placed four different doses of samples,bacteria were incubated at 37℃in 24h.then observe the size of inhibition zone.24h replacement every dish. the inhibition zone were observed at 24h, 48h,72h,96h,1 week, up until diameter the inhibition zone less than 6mm.④biomechanical test:A:The compressive strength of bone cement:for each cylinder, record the force caused by rupture or 2% of the yield strength or the yield point load, That first appeared on the record that, the force divided by the original section of the cylinder,MPa as units of compression strength,Calculate the average 6 cylinder compressive strength. B:Determination of bending strength bone cement: triclosan,gentamicin and bone cement were mixed respectively, Control group, the bone cement were pouring into the mold, after shaping, strip of all the experiments will poured into the four-point bending test device, record deviation from the strip center. increasing force until the test slab fracture. Record the force at fracture.CHISS2004 software was used for statistical analysis, and measurement data were expressed in the form of mean value±standard deviation((?)±s). antibacterial activity of different doses applied analysis of variance between the two groups.Results:1. the role of antibacterial activity of time-dependent bone cement loading with triclosan and gentamicin bone cement.1.1 With the dose increased, bone cement of 0.5～2.0g of triclosan and gentamicin sulfate on Staphylococcus aureus, Staphylococcus epidermidis, Escherichia coli was inhibited. The antibacterial activity of bone cement increased significantly, However, in certain period of observation, two different antibacterial agents change, the antibacterial activity of triclosan was stronger than that of gentamicin sulfate in 1.0g. Control group (without any antibiotic bone cement) without antibacterial activity.1.2 The bone cement at the same dose within24h, of gentamicin sulfate and triclosan was no significant difference. After 48h, diameter of inhibition zone of triclosan was larger than the zone diameters of gentamicin sulfate, control duration of the bone cement, the antibacterial activity of triclosan was longer than gentamicin,the average length 48h(p<0.05). Both bone cements against Gram-positive bacteria were significantly decreased adhesion (p<0.05). However, gentamicin sulfate to E. coli bacteria was significantly better than triclosan.2. Biomechanical analysis of two kinds of antibacterial bone cement. according to ISO 5833 "surgical implants-acrylic resin cement" standard, determination of bio-mechanical properties of bone cement loading with triclosan. one is the pressure test, and the second is a four-point bending test. the pressure test showed that adding the right amount of triclosan did not affect the compressive strength of bone cement, 40g to 2.0g triclosan mixing bone cement, the compressive strength were greater than 70MPa, better than the ISO 5833 standard (strength 70MPa), and similar to bone cement without antibiotics. according to ISO 5833 to the four-point bending test, triclosan bone cement product can meet this standard, the bending modulus (MPa)>1800MPa, bending strength>>50 MPa.Conclusion:1 Triclosan bone cement coMPared with Gentamicin bone cement at present study,have a wide range of bacteria, especially in today's clinical infections bacteria (Staphylococcus aureus) has a good antimicrobial effect.2 Bone cement loading with triclosan Triclosan coMPared with bone cement loading with Gentamicin at present study, effective antimicrobial agent release, antibacterial longer. because triclosan is an antibacterial fungicide, which is different from commonly used clinical antibiotics, It is a single target of the fungicide,therefore, resistance to gentamicin, and triclosan does not.3 Pressure test and four-point bending test showed that the compressive effect of experimental dose similar to bone cement without antibiotics.flexural modulus and flexural strength are up to standard.Our experiment in vivo shows that antibacterial activity of bone cement loading with triclosan offer better than bone cement loading with Gentamicin. bone cement loading with triclosan have a stronger, more durable antibacterial activity. It offers elementary experiment support for prevention of postoperative infection of the first artificial joint replacement and joint revision surgery in the further.