The Elution Properties And Antibacterial Activity Of Vancomycin?Imipenem-cilastatin?Moxifloxacin Loaded Bone Cement In Vitro Experimental Study

Objective:The aim of this vitro study was to investigate the elution properties and antibacterial activity for bone cement loaded with vancomycin,imipenem-cilastatin,moxifloxacin and explore better antibiotic loaded bone cement with wider antibacterial spectrum and stronger antibacterial effect,so as to provide a reference for the treatment of post-traumatic bone infection.Method:40g Palacos R PMMA bone cement powder without antibiotics was mixed with 1g or 2g vancomycin,imipenem-cilastatin,moxifloxacin,respectively.By using the special mould which was developed before,prepared the 6 experimental groups specimen of ALBC,control group was Palacos R PMMA bone cement without antibiotics,the prepare method as above.Each bead was placed in 1 mL of saline and took samples at different time points.Antibiotic concentrations were determined using high-performance liquid chromatography.Antibacterial activity was determined by placing the ALBC on the plate with different bacteria including MRSA,Escherichia coli,Enterococcus faecalis,Pseudomonas aeruginosa.The diameter of antibacterial area and duration were measured.Results:During the 14 days of experimental observation,except the group of IMP(lg)with only 11 days,the continuous elution of antibiotics was found in the other experimental groups and the rate of elution decreased with time in accordance with an exponential pattern.The dosage of 2g of antibiotics had better elution properties than that of the corresponding antibiotics with dosage of 1g.VAN group had the best elution properties among the three antibiotics.MFX group had the better total elution amount than IMP group.IMP group had the better elution ratio than IMP group.The antibacterial experiment showed that antibiotics can continue to be released from bone cement and the continuous antibacterial effect was observed.VAN ALBC showed antibacterial activity only for gram-positive bacteria.IMP and MFX ALBC showed antibacterial activity for both gram-positive and gram-negative bacteria,but showed no antibacterial effect on MRS A,MFX ALBC showed the best antibacterial activity for Escherichia coli,Enterococcus faecalis,Pseudomonas aeruginosa among the three kind ALBC.With the increase of dose of antibiotics,the antibacterial activity of ALBC increased as well as the antibacterial duration.All the experimental groups in the first 24 hours had the largest diameter of antibacterial area,namely,the ALBC during the first 24 hours had the strongest antibacterial activity.As time went by,the antibacterial effect decreased gradually.The control group showed no antibacterial activity and no antibiotic elution was found during the experimental study.Conclusion:1.ALBC loaded with 2g antibiotics has better elution properties and antibacterial activity than ALBC loaded with 1g antibiotics.2.VAN ALBC has good elution properties and shows strong antibacterial activity for gram-positive bacteria especially for MRSA.3.Both IMP and MFX have wider antibacterial spectrum and show good antibacteria activity for gram-negative bacteria,MFX ALBC have shown the best antibacterial activity for Escherichia coli,Enterococcus faecalis,Pseudomonas aeruginosa among the three kind ALBC.4.The ALBC beads used in this experiment which were made by special mould have larger surface area-to-volume ratio and also have shown better performance in terms of elution properties.