Objective To evaluate the characterization, biocompatibil ity in vitro and in vivo, and antimicrobial activity of an injectable vancomycin-loaded borate glass/chitosan composite (VBC) so as to lay the foundation for its further cl inical application. Methods The sol id phase of VBC was constituted by borate glass and vancomycin, liquid phase was a mixture of chitosan, citric acid, and glucose with the proportion of 1 ∶ 10 ∶ 20. Solid phase and liquid phase was mixed withthe ratio of 2 ∶ 1. Vancomycin-loaded calcium sulfate (VCS) was produced by the same method using calcium sulfate instead of borate glass and sal ine instead of chitosan, as control. High performance liquid chromatography was applied to detect the release rate of antibiotics from VBC and VCS, and minimum inhibitory concentration (MIC) was tested by using an antibiotic tube dilution method. The structure of the VBC and VCS specimens before and 2, 4, 8, 16, and 40 days after immersion in D-Hank’s was examined by scanning electron microscopy, and the phase composition of VBC was analysed by X-ray diffraction after soaked for 40 days. Thirty-three healthy adult New Zealand white rabbits (weighing, 2.25-3.10 kg; male or female) were used to establ ish the osteomyel itis models according to Norden method. After 4 weeks, the models of osteomyel itis were successfully established in 28 rabbits, and they were randomly divided into 4 groups (groups A, B, C, and D). In group A (n=8), simple debridement was performed; in groups B and C (n=8), defect was treated by injecting VCS or VBC after debridement; and in group D (n=4), no treatment was given. The effectiveness of treatment was assessed using radiological and histological techniques after 2 months. Results The releases of vancomycin from VBC lasted for 30 days; the release rate of vancomycin reached 75% at the first 8 days, then could reached more than 90%. The releases of vancomycin from VCS lasted only for 16 days. The MIC of VBC and VCS were both 2 μg/mL. The VCS had a smooth glass crystal surface before immersion, however, it was almost degradated after 4 days. The fairly smooth surface of the VBC pellet became more porous and rougher with time, X-ray diffraction analysis of VBC soaked for 40 days indicated that the borate glass had gradually converted to hydroxyapatite. After 2 months, the best result of treatment was observed in group C, osteomyelitis symptoms disappeared. The X-ray scores of groups A, B, C, and D were 3.50 ± 0.63, 2.29 ± 0.39, 2.00 ± 0.41, and 4.25 ± 0.64, respectively; Smeltzer scores were 6.00 ± 0.89, 4.00 ± 0.82, 3.57 ± 0.98, and 7.25 ± 0.50, respectively. The scores were significantly higher in group D than in groups A, B, and C (P lt; 0.05), and in group A than in groups B and C (P lt; 0.05). The scores were higher in group B than in group C, but no significant difference was found (P gt; 0.05). Conclusion The VBC is effective in treating chronic osteomyelitis of rabbit by providing a sustained release of vancomycin, in addition to stimulating bone regeneration, so it may be a promising biomaterial for treating chronic osteomyelitis.
Objective To observe the inhibitory characteristics of silver nanoparticles (AgNP) on bacterial biofilms and investigate their inhibitory effect on biofilm formation on three common orthopedic biomaterials. Methods The minimal inhibitory concentration (MIC) and minimal biofilm inhibitory concentration (MBIC) of AgNP were determined by microplate dilution assay. Biofilms of Staphylococcus aureus (ATCC 25923) were cultured on three orthopedic biomaterials (titanium alloy, titanium oxide, and stainless steel) and intervened with AgNP at concentrations of 32, 16, 8, 4, 2 and 0 μg/mL to determine the MBICs on the three materials. The effects of AgNP on biofilm formation were analyzed by scanning electron microscopy and measuring optical density. Results The MIC and MBIC of AgNP in the microplate assay were both 16 μg/mL. The MBICs of AgNP on biofilm formation in titanium oxide, titanium alloy, and stainless steel were 16 μg/mL, 32 μg/mL, and 32 μg/mL, respectively. Among the three materials, the lowest optical density was observed on titanium oxide, while the highest was on titanium alloy. Conclusions AgNP has strong antibacterial biofilm characteristics and can prevent the formation of Staphylococcus aureus biofilm in vitro. Biofilm formation is most pronounced on titanium alloy, least on titanium oxide, and intermediate on stainless steel.
目的 分析下肢慢性創傷性骨髓炎患者創面細菌培養分布情況，為臨床用藥提供依據。 方法 對2006年1月－2010年12月收治的91例慢性骨髓炎患者創面分泌物細菌培養標本結果進行回顧性調查分析。其中男78例，女13例；年齡5～78歲，平均41.3歲。病程47 d～7個月，平均68.6 d。使用抗生素總療程均＞7 d。 結果 65例創面細菌培養陽性患者共分離出113株病原菌，其中G?菌72株，占63.71%；G+菌41株，占36.28%。藥敏結果顯示，G+菌對常規青霉素類基本耐藥，碳青霉烯類耐藥菌株少見，對萬古霉素耐藥菌株尚未出現。G?菌對青霉素類及頭孢菌素類耐藥較高，對頭孢哌酮－舒巴坦無耐藥。 結論 加強對慢性創傷性骨髓炎患者創面病原菌監測極為必要,對臨床抗生素的合理使用具有一定的指導意義。Objective To analyze the distribution of cultured bacteria from chronic osteomyelitis patients, and provide a basis for clinical medicine. Methods We retrospectively analyzed the bacterial culture results of the secretions from 91 patients with chronic osteomyelitis treated in our hospital from January 2006 to December 2010. Among them, there were 78 males and 13 females aged from 5 to 78 years averaging at (41.3 ± 8.35) years. The duration of the disease ranged from 47 days to more than 7 months, averaging (68.6 ± 14.57) days. The total course of antibiotic-taking was longer than 7 days for all the patients. Results A total of 113 pathogen strains were isolated from 65 secretion samples, including 72 Gram-negative bacteria accounting for 63.71% and 41 gram-positive bacteria accounting for 36.28%. Drug susceptibility results showed basic resistance of Gram-positive bacteria to conventional penicillin, rare resistance to carbapenem, and no resistance to vancomycin. Gram-negative bacteria were basically resistant to penicillin and cephalosporins, but not resistant to cefoperazone-sulbactam. Conclusion Enhancing the monitoring of pathogens for patients with chronic osteomyelitis is extremely necessary for the rational clinical use of antibiotics.
Objective Bioactive borate glass (BG) has good biocompatibil ity and biodegradation. To investigate the feasibilty of bioactive borate glass as a carrier of the antibiotic controlled-releasing by implanting vancomycin-loaded BG (VBG)into the focus of tibia chronic osteomyel itis after debridement. Methods VBG and vancomycin-loaded calcium sulfate (VCS) were prepared with a vancomycin content of 80 mg/g. Sixty-five New Zealand white rabbits, weighing 2.12-3.91 kg (mean, 2.65 kg), were used. The tibia chronic osteomyel itis rabbit models were establ ished by injecting methicill in-resistant Staphylococcus aureus (MRSA, 0.1 mL, 1 × 109 cfu/mL) into the right tibia of 65 rabbits. After 3 weeks of injection, 54 rabbits of successful models were randomly divided into groups A (n=11), B (n=11), C (n=16), and D (n=16). Simple debridement was performed in group A; BG, VCS, and VBG were implanted into the infection sites of groups B, C, and D respectively after thorough debridement. A sample of the debrided tissues was harvested for bacterial examination. The vancomycin serum levels were determined in groups C and D at 1, 2, 4, 10, 24, and 48 hours after operation. The boron serum levels were determined in groups B and D at 10, 24, 48, 72, and 120 hours after operation. After 8 weeks, the effectiveness was assessed radiographically, bacteriologically, and histopathol ogically. Results Ten rabbits died after operation. No vancomycin was detected in group C; the vancomycin level increased gradually, reached the highest level at 4 hours after operation, and then decreased rapidly in group D. No boron was detected in group B; the boron reached the highest serum level at 10 hours after operation, and then decreased gradually in group D. At 8 weeks, calcium sulfate degraded in group C; BG degraded partially in group D; and no obvious degradation was observedin group B. The repair effect was better in group D than in group C. There was no significant difference in radiograph scoring between groups A, B, C and D (P gt; 0.05) before operation, but there was significant difference between group D and groups A, B, C (P lt; 0.05) at 8 weeks after operation. The bacterial culture showed that all the MRSA results were positive in 4 groups. At 8 weeks, the negative rates of MRSA examination were 36.36%, 18.18%, 73.33%, and 81.25% respectively in groups A, B, C, and D, showing significant differences between group D and groups A, B (P lt; 0.05). The histopathological observation showed that a large number of new bones formed and no foreign body reaction occurred in group D. The histopathologic scores of groups A, B, C, and D were 6.45 ± 3.62, 7.55 ± 3.36, 4.27 ± 2.91, and 3.81 ± 3.04 respectively, showing significant differences between group D and groups A, B, and between group C and group B (P lt; 0.05). Conclusion VBG can improve the repair of bone defect in the treatment of chronic osteomyel itis.
Objective To investigate the method and clinical effect of free iliac flap grafting in repairing the tibia traumatic osteomyelitis complicated withboneskin defect. Methods From June 2001 to February 2006，28 patients with tibia traumatic osteomyelitis complicated with boneskin defect were treated with free iliac flap grafting at stageⅠ. There were 18 males and 10 females, with an average of 32.5 years(1868 years). There were traffic injury in 11 cases, bruise in 6 cases, explosive injury in 5 cases, machinery injury in 4 cases, and falling injury in 2 cases. The disease courses of patients were 1-6 months. All patients had been treated by 26 operations. The wounds located at the mid and upper tibia in 13 cases, and the inferior tibia in 15 cases. The length of free iliac was0.5-6.0 cm and the size of the flap ranged from 4.5 cm×3.5 cm to 28.0 cm×16.0 cm.The external fixation were applied in 18 cases, and steel plate were applied in 10 cases. The donor sites were sutured directly. Results All of the flaps survived completely. The wounds healed by first intention in 26 cases and by second intention in 2 cases. The donorsites healed by first intention. Twentyeight patients were followed up for 6 to 56 months(mean, 30 months).The appearances of the flaps were satisfactory and the colour was similar to recipient site. All grafted bone united 2-14 months (mean，4.6 months) after operation according to X-ray examination. In 20 patients who did not achieved union before operation, fracture healed 2 to 6 months after operation(mean, 3.2 months). Osteomyelitis recurred 12 months after operation in 2 cases and healed by nidus clearing. Conclusion Free iliac flap which used to repair tibia traumatic osteomyelitis complicated with boneskin defect, can repair the defect at stageⅠand enhance the antiinfectious ability. It isone of appropriate and effective clinical methods.
Objective To explore a surgical method for chronic osteomyel itis of sternum after thoracotomy. Methods From January 2006 to February 2009, 11 cases of chronic osteomyelitis after thoracotomy (2 cases of coronary bypass, 6 cases of mitral valve replacement, and 3 cases of ventricular defect repair) were admitted. Of them, there were 6 males and 5females, aged from 6 to 62 years (median 34 years), including 6 cases of simple osteomyelitis of sternum, 2 cases of osteomyelitis of sternum with suppurative infection of mediastinum, and 3 cases osteomyel itis of sternum with costal chondritis. Necrotic sternum were excised and defect was from 4 cm × 3 cm to 7 cm × 4 cm. Greater pectoral muscle flap was designed from 8 cm × 5 cm to 10 cm × 6 cm on one side and was transferred to defect. Negative drainage and sensitive antibiotics were administered after operation. Results Healing by first intention was achieved in 10 patients except 1 patient who had a few discharge at the drainage outlet and whose incision healed 1 week later. The follow up was from 3 to 10 months with an average of 6 months. The formed scars were flat with soft texture in 8 patients and moderately hypertrophy in 3 patients. The wounds healed without pain, relapse or abnormal function of donor upper limb. Conclusion Transplantation of greater pectoral muscle flap is an effective way to repair chronic osteomyelitis of sternum after thoracotomy.
ObjectiveTo review the related studies on the application of nanomaterials in the treatment of osteomyelitis, and to provide new ideas for the research and clinical treatment of osteomyelitis.MethodsThe literature about the treatment of osteomyelitis with nanomaterials at home and abroad in recent years was reviewed and analyzed.ResultsAt present, surgical treatment and antibiotic application are the main treatment options for osteomyelitis. But there are many defects such as antibiotic resistance, residual bone defect, and low effective concentration of local drugs. The application of nanomaterials can make up for the above defects. In recent years, nanomaterials play an important role in the treatment of osteomyelitis by filling bone defects, establishing local drug delivery system, and self-antibacterial properties.ConclusionIt will provide a new idea and an important research direction for the treatment of osteomyelitis to fully study the related characteristics of nanomaterials and select beneficial materials to make drug delivery system or substitute drugs.
Objective To overview the effect of bacterial biofilms (BBF) on the formation of chronic osteomyel itis and the treatment measure. Methods The original articles in recent years about the relationship between BBF and chronic osteomyel itis were reviewed. Results The diagnosis and treatment of chronic osteomyel itis was very difficult, besides hyperplasia oflocal scar, poor blood supply, drug-resistant, forming of BBF also was an important reason. BBF formed on the surface of necrosis soft tissue and dead bone. Due to the protection of BBF, the bacterium were far more resistant to antimicrobial agents, which caused the recurrence of chronic osteomyel itis. The forming of BBF included three processes which were adhesion, development and maturity. As the major pathogens of chronic osteomyel itis, staphylococcus had its own characteristic. Designing therapeutic programmes according to these characteristics had become the trend of anti-infection treatment of BBF. Conclusion Although there are lots of studies on anti-biofilm due to the key factors during the forming of BBF, the most effective way of anti-biofilm is still debridement.
