Objective To observe the effect of cationic liposomal ceftazidime (CLC) combined with nano-hydroxyapatite/β-tricalcium phosphate (n-HA/β-TCP) in the treatment of chronic osteomyelitis of rabbits. Methods Thirty healthy New Zealand white rabbits (4-6 months old; weighing, 2-3 kg) were selected to prepare the chronic osteomyelitis models. After 4 weeks, the gross observation, X-ray examination, and bacteriological and histopathological examinations were done; the models were made successfully in 27 rabbits. Of 27 rabbits, 24 were randomly divided into 4 groups (n=6): only debridement was performed in group A; ceftazidime was given (90 mg/kg), twice a day for 8 weeks after debridement in group B; ceftazidime and n-HA/β-TC were implanted after debridement in group C; and CLC and n-HA/β-TCP were implanted after debridement in group D. Before and after treatments, X-ray examination was done, and Norden score was recorded. At 8 weeks after treatment, the specimens were harvested for gross observation and for gross bone pathological score (GBPS) using Rissing standard; half of the specimens was used for histological observation and Smeltzer scoring, the other half for bacteriological examination and calculation of the positive rate of bacteria culture. Results At 8 weeks after treatment, Norden score of group D was significantly lower than that of groups A, B, and C (P lt; 0.05), but no significant difference was found among groups A, B, and C (P gt; 0.05). At 8 weeks after treatment, sinus healed in groups C and D, but sinus was observed in groups A and B; the GBPS scores of groups C and D were significantly lower than those of groups A and B (P lt; 0.05). The Smeltzer scores of groups C and D were significantly lower than those of groups A and B (P lt; 0.05). The positive rates of bacteria culture of groups C (0) and D (0) were significantly lower than those of group A (25.0%) and group B (16.7%) (P lt; 0.05). Conclusion CLC combined with n-HA/β-TCP has good effect in treating chronic osteomyelitis of rabbits, and it has better effect in treating chronic osteomyelitis of rabbits than ceftazidime with n-HA/β-TCP.
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 discuss the effectiveness of antibiotic-impregnated cement temporary spacer for osteomyel itis and nonunion of bone caused by intramedullary fixation. Methods Between June 2002 and May 2006, 12 patients with chronic osteomyel itis and nonunion of bone caused by intramedullary nail ing were treated, including 8 males and 4 females with an average age of 40.2 years (range, 26-53 years). The fracture locations included tibia in 7 cases and femur in 5cases. Infection occurred within 2 weeks after intramedullary fixation in 7 cases and within 3 months in 5 cases. The mean time from infection to admission was 5 months (range, 1-24 months). The results of bacteria culture were positive in 10 cases and negative in 2 cases. White blood cell (WBC) count, erythrocyte sedimentation rate (ESR), and C-reactive protein (CRP) were higher than normal values. An antibiotic-impregnated cement temporary spacer was inserted after removal of biomembrane and internal fixator, thorough debridement and irrigation. After osteomyel itis was controlled by antibiotic therapy postoperatively, two-stage bone transplantation and internal fixation were performed after 3 to 6 months. Results All wounds healed by first intention without early compl ication. All cases were followed up 24 to 48 months (mean, 34 months). WBC count, ESR, and CRP were normal at 3 months postoperatively. The X-ray films showed the fracture heal ing at 10-14 weeks after operation (mean, 12 weeks). Expect one patient had knee range of motion of 90°, the lower l imb function of the others returned to normal. No infection recurred during follow-up. Conclusion Antibiotic-impregnated cement temporary spacer could control osteomyelitis and nonunion of bone caused by intramedullary nail ing, and two-stage bone transplantation and internal fixation after osteomyelitis is an effictive and ideal way to treat osteomyelitis and nonunion of bone caused by intramedullary nail ing.
Objective To review the research progress in the treament of bone defect or osteomyel itis with drug-carried bionic nano-bone so as to offer some theoretic supports and experimental references for those relative researchers. Methods The related l iterature was reviewed. The research progress in the treatment of bone defect or osteomyel itis with drug-carried bionic nano-bone was analyzed, which included the designing and preparing of drug-carried nano composites, the way of making infected bone defect animal models, and the general steps, test indexes and results. ResultsTraumatic osteomyel itis and bone defect were two kinds of disease to difficultly cure in nowadays cl inical orthopaedics. The osteomyel itis, especially chronic one was quite troublesome during the treatments. Many researchers made artifical bone with nano-materials and added drugs into them by various ways for the purpose of controlling infection and repairing bone defection simultaneously. But these researches were still at the laboratory phase, lacking the criterions of making relative animal models, and needed to be improved in the way of drug slow-releasing and nano-scaffold producing. Conclusion The drug-carried bionic nano-bone as a kind of newly emerging replacement material has splendid effects in the treatments of traumatic large area bone defect or osteomyelitis and will have a brill iant future.
Objective Platelet-rich plasma (PRP) contains high concentrations of platelets and leucocytes, which play a key role in antimicrobial host defense system. To evaluate the antimicrobial efficacy of autologous PRP in vitro and in vivo and to explore the mechanism of action so as to provide the experimental basis for the prevention and treatment of bone infection. Methods PRP was prepared with the method of two centrifugation from 15 health volunteers. Platelet-leukocytegel (PLG) was obtained after activation of PRP with bovine thrombin. Next, PLG was incubated with Staphylococcus aureus (1 × 106 cfu/mL) in vitro compared with PRP, platelet-poor plasma (PPP) and PBS. Samples were taken out after 2, 4, 6, 8, 12, and 24 hours for bacterial culture and colony count. Thirty-six New Zealand adult rabbits, weighing (2.85 ± 0.11) kg, were divided into 4 groups: PLG (n=10), antibiotic (n=10), infection (n=10), and PBS (n=6) groups. The osteomyel itis models were made by injecting 0.1 mL Staphylococcus aureus suspension (1 × 106 cfu/mL) into the tibial canal in PLG group, antibiotic group, and infection group; equal volumes of PBS was injected in PBS group as a control. Autologous PLG was injected immediately after operation in PLG group. Cefazol in (30 mg/kg) was injected through the auricular vein from 1 hour before operation to 72 hours after operation in antibiotic group, once per 8 hours. No treatment was given in infection and PBS groups. The efficacy of PLG for osteomyel itis prophylaxis was evaluated by microbiological, X-ray and histological observation within 28 days. Results The contents of leucocyte and platelet of PRP were 6.2 times and 5.5 times of whole blood, showing signficant differences ((P lt; 0.05); the contents of leucocyte and platelet of PPP were significantly lower than those of whole blood and PRP ((P lt; 0.05). In vitro test showed that PLG had the most obvious bacteriostasis effect. The bacterial count reached a minimum value at 4 hours after incubation in PLG and at 6 hours after incubation in PRP. PPP had slow and no obvious bacteriostasis effect and PBS had no bacteriostasis effect. At 2, 4, 6, 8, 12, and 24 hours of incubation, the bacterial count reduced significantly when compared PLG with PRP and PPP (P lt; 0.05), when compared PRP with PPP (P lt; 0.05). In PLG group and antibiotic group, 1 rabbit died, respectively; 34 rabbits survived to the end of the experiment. There was no significant difference (P gt; 0.05) in temperature, body weight, erythrocyte sedimentation rate and content of leucocyte between 28 days after operation andbefore operation in 4 groups. After 28 days, the X-ray scores were 2.78 ± 1.39, 1.55 ± 1.48, 4.17 ± 1.25, and 0 in PLG, antibiotic,infection, and PBS groups, respectively, which was significantly higher in infection group than in other 3 groups ((P lt; 0.05). Also, the histological scores were 5.89 ± 3.92, 3.00 ± 2.31, 10.33 ± 4.03, and 0, respectively, which was significantly higher in infection group than in other 3 groups (P lt; 0.05), and was significantly lower in antibiotic group than in PLG group ((P lt; 0.05). The results of bacterial culture showed that the infection rates of PLG group (44.4%) and antibiotic group (20.0%) were significantly lower ((P lt; 0.05) than that of infection group (88.9%). The quantitative analysis of bacteria showed that the number of bacteria was signifcantly lower ((P lt; 0.05) in PLG and antibiotic groups than in infection group. Conclusion PRP forms into PLG after activating, it can inhibit Staphylococcus aureus reproduction in vitro and can effectively prevent bone infection in vivo.
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 develop the plastic nano-hydroxyapatite (nano-HA)/poly (3-hydroxybutyrate-hydroxyvalerate) polyethylene glycol(PHBV-PEG) gentamicin (GM) drug delivery system(DDS)(nano-HA/PHBV-PEG-GM-DDS) for treating osteomyelitis and find its releasing character in vivo. Methods The plastic nano-HA/PHBV- PEG-GM-DDS was prepared using nanoHAas the core carrier of GM, nano-HA with PHBV and PEG as coating and plastic fibrin glue(FG) as microsphere scaffold. The morphological features of nano-HA,drug loaded nano-HA and drug loaded nano-HA/PHBVPEG microsphere were examined by electron microscope.The GM concentration in blood, cortex bone and cancellousbone was detected at 12 different time points by the method of K-B after the plastic nano-HA/PHBV-PEGGM-DDS was implanted into the femora of 36 rabbits. Its GM releasing character was assayed in vivo. Results Nano-HA was similar to a blackjack, and its length was less than 60 nm. Drug loaded nano-HA appeared natural crystal condensate, of which surface adsorbed massive GM. The average grain diameter was 200.5 nm. Drug loaded nanoHA/PHBV-PEG microsphere had a shrinkable porous structure, of which surface configuration was consistent. The average grain diameter was 34.5 μm. The GM concentration and the antibacterial annulus was in the linear correlation. The correlation coefficient was 0.998. In cortex and cancellous bone tissue, the GM concentration was about 95.50±16.50 μg/ml and 80.20±13.80 μg/ml from the plastic nano-HA/PHBV-PEG-GM-DDS on the 1st day, then decreased gradually. After 56 days of operation, the GM concentration still exceeded the minimum inhibitory concentrationfor the staphylococcus aureus, but the peak level of serum GM concentration wasunder the nephrotoxicity concentration. Conclusion Plastic nano-HA/PHBV-PEG-GM-DDS was a good drug delivery system with sustained antibiotic effect in vivo. It was an effective method for the treatment of osteomyelitis.
An clinical and pharmacokinetic study for a drug delivery system (DDS) of gentamycin-loaded chitosan bar were carried out with the purpose to evaluate its efficacy and giving further data for its clinical applications. Eighteen cases of chronic osteomyelitis were treated by surgical necrectomy with implantation of gentamycin-load chitosan bar in the prepared bone cavity. After operation, the concentration of gentamycin in serum and wound drainage fluid were examined at different times and blood urea nitrogen (BUN) and serum creatinine (Cr) as well. The clinical results were evaluated by the conditions of wound healing and clinical and roentgenographic manifestations. The results showed that the serum gentamycin concentration reached its peak level (0.86 microgram/ml) at 24 hours after operation and lasted for 4 days. No increase in the concentrations of BUN and Cr were observed after implantation. The gentamycin concentration in wound drainage fluid was several hundred times higher than the minimum inhibitory concentration (MIC) for staphylococcus aureus. All of the 18 cases were followed up for 24.8 months (in an range of 6-34 months) 16 patients received initial cure and without any recurrence. So, it could be concluded that the gentamycin-loaded chitosan DDS was a simple and effective method for the treatment of chronic osteomylitis without the necessity to carry out a second operation to remove the drug carrier, and it was sound to popularize its clinical application.
ObjectiveTo explore the effectiveness of induced membrane technique of hollow porous antibioticimpregnated bone cement forming in vitro and lavage in vivo for the treatment of osteomyelitis. MethodsBetween January 2010 and March 2014, 14 cases of osteomyelitis were treated by induced membrane technique of hollow porous antibiotic-impregnated bone cement forming in vitro and lavage in vivo after debridement at the first stage, then the bone cement with bone graft was replaced during the induced membrane after infection was controlled at the second stage. The time from first to second stage operation was 8-12 weeks (average, 10.2 weeks). There were 11 males and 3 females, aged 18 to 69 years (average, 39.2 years). According to Cierny-Mader classification of osteomyelitis, 2 cases were rated as intramedullary type, 5 cases as limited type, and 7 cases as diffusing type. The course of osteomyelitis was 3 months to 20 years, averaged 1.9 years. The healing of bone defect and the functionary recovery of adjacent joint were evaluated according to Paley's method. ResultsDebridement was performed for two times in 1 case, and for one time in 13 cases for control of bone infection at the first stage. All incisions healed by first intention after second stage. All patients were followed up 15-48 months (average, 13.4 months), with no recurrence of infection. All bone defects healed, and the clinical healing time was 4-5 months (average, 4.4 months). The results of bone healing grade were excellent in all cases at 1 year after operation; the functional recovery of adjacent joint at last follow-up was excellent in 4 cases, good in 8 cases, and fair in 2 cases, and the excellent and good rate was 85.7%. ConclusionInduced membrane technique of hollow porous antibiotic-impregnated bone cement forming in vitro and lavage in vivo for treatment of osteomyelitis has the advantages of high rate of elution of antibiotics, ease of lavage of medullary cavity, and no damage to induced membrane and bony interface between bone and bone cement when removing cement, it is effective for control of bone infection and repair of bone defect.
ObjectiveTo investigate the molecular mechanism of osteoclast differentiation induced by Staphylococcal peptidoglycan (PGN-sa). MethodsRaw264.7 cells were stimulated with PGN-sa and with PGN-sa+SC75741[a potent inhibitor of nuclear factor κB (NF-κB) activation] in a concentration of 200 ng/mL. The protein expression of nuclear factor of activated T-cells cytoplasmic 1 (NFATc1) was tested at 0, 1, 2, and 3 days; the proteins related to osteoclast differentiation of extracellular regulated protein kinases (ERK), p38, c-Jun N-terminal kinase (JNK), NF-κB, inhibitor of NF-κB (IκB-α), Akt, and the phosphorylation forms of p38, ERK, JNK, Akt, NF-κB were measured at 0, 5, 10, 20, 40, and 60 minutes by Western blot. In addition, Raw264.7 cells were stimulated with PGN-sa in the concentrations of 100 ng/mL (group A), 200 ng/mL (group B), 400 ng/mL (group C), and with PBS (group D) for 1, 2, and 3 days; the expression levels of tumor necrosis factor α (TNF-α), interleukin 1α (IL-1α), and IL-6 were detected by ELISA. ResultsThe results of Western blot showed that the expression of NFATc1 increased gradually with time, showing significant difference between different time points (P<0.05). However, after SC75741 was added, the expression of NFATc1 was inhibited at 2 and 3 days, showing significant difference when compared with no addition of SC75741 (P<0.001). After stimulation of PGN-sa, the expression of IkB-α decreased significantly at 5 and 10 minutes when compared with those at the other time points (P<0.001), and returned to normal at 20 minutes. Meanwhile, the expression of p-NF-κB increased significantly at 5 and 10 minutes when compared with those at the other time points (P<0.001), and returned to normal at 20 minutes; and the expression of p-NF-κB at 5 minutes was significantly higher than that at 10 minutes (P<0.001). After the addition of SC75741, there was no change in the expressions of IκB-α and p-NF-κB, showing no significant difference between different time points P>0.05). Moreover, the expressions of ERK, p38, JNK, NF-κB, Akt, p-p38, p-ERK, p-JNK, and p-Akt showed no significant change between different time points P>0.05). ELISA results showed that there were no expressions of TNF-α and IL-1α in groups A-D at different time points. The expression of IL-6 had an increasing trend with time prolonged in each group, showing significant differences between different time points (P<0.05). Moreover, at 1 day after culture, the expression of IL-6 showed no significant difference among groups P>0.05). At 2 and 3 days after culture, the expression of IL-6 in groups A-C showed an increasing trend and was significantly higher than that in group D, showing significant difference among groups (P<0.05). ConclusionPGN-sa can promote osteoclast differentiation through NF-κB signaling pathway, and IL-6 may play a role in this process.