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Background. Chondrocyte metabolic disorder plays an important role in the development of osteoarthritis (OA). The use of statins in the treatment of OA has also been widely studied, but the mechanism is still confusing. The present study aims to investigate the effects of statin on osteoarthritis chondrocytes and its underlying mechanism. Major findings. An untargeted metabolomics study revealed that the treatment of statins significantly changed the metabolites of articular cartilage tissues collected from female osteoarthritis patients, and might be involved in the glycerophospholipid metabolism pathway. In vitro study showed that 5–50 μmol/L of pravastatin exerts no cytotoxicity on human chondrocytes. Besides, 50 μmol/L of pravastatin caused a significant decrease in the expression of matrix metalloproteinase (MMP)-1 and MPP-13, and intracellular cholesterol in interleukin-1β (IL-1β)-induced human chondrocytes. Furthermore, at both mRNA and protein levels, the expression of the proteins related to the cholesterol efflux pathway (liver X receptor and cholesterol efflux regulatory protein) were significantly up-regulated by 50 μmol/L of pravastatin in IL-1β-induced human chondrocytes. Conclusion. Pravastatin can reduce the expression of MMPs in IL-1β-induced human chondrocytes and protect the chondrocyte matrix. The mechanism may be related to promoting the expression of proteins related to the cholesterol efflux pathway and reducing the level of cellular cholesterol.

Background Stromal cell-derived factor-1 (SDF-1) plays an important role in the osteoblastic differentiation of human bone marrow mesenchymal stem cells (hBMMSCs), but the specific mechanism remains unclear. Our study aimed to clarify the role of the lncRNA-H19/miR-214-5p/BMP2 axis in the osteoblastic differentiation of hBMMSCs induced by SDF-1. Methods We used reverse transcriptase-polymerase chain reaction, western blotting, alkaline phosphatase activity test, and Alizarin red staining to evaluate the osteoblastic differentiation of primary hBMMSCs and the luciferase reporter assay to determine if lncRNA-H19 binds with miR-214-5p. Results Our results indicated that SDF-1 (50 ng/mL) promotes the osteoblastic differentiation of hBMMSCs, significantly upregulated osteoblastogenic genes (OCN, OSX, RUNX2, and ALP) and increased Alizarin red staining, alkaline phosphatase activity, and lncRNA-H19 expression. The luciferase reporter assay verified that lncRNA-H19 binds with and represses miR-214-5p, thereby upregulating BMP2 expression. Use of miR-214-5p inhibitor or overexpression of lncRNA-H19 can promote the osteoblastic differentiation of hBMMSCs, but miR-214-5p or shH19 inhibits the osteoblastic differentiation of hBMMSCs. Treatment with an miR-214-5p inhibitor could rescue the inhibitory effect of shH19 on the osteoblastic differentiation of hBMMSCs. Conclusions Taken together, SDF-1 promotes the osteoblastic differentiation of hBMMSCs through the lncRNA-H19/miR-214-5p/BMP2 axis. Increased osteoblastic differentiation by an miR-214-5p inhibitor reveals a new possible strategy for the treatment of bone defect and osteoporosis.

Calcium phosphate coatings have been applied on the surface of Ti implants to realize better osseointegration. The formation of dicalcium phosphate dihydrate (CaHPO 4 ·2H 2 O), mineralogically named brushite on pure Ti substrate has been investigated via chemical conversion method. Coating composition and microstructure have been investigated by X-ray diffractometer, Fourier transform infrared spectrometer and field emission scanning electron microscope. The results reveal that the coatings are composed of high crystalline brushite with minor scholzite (CaZn 2 (PO 4 ) 2 ·2H 2 O). A micro/nano-scaled fibrous morphology can be produced in the acidic chemical conversion bath with pH 5.00. The surface of the fibrous brushite coating exhibits high hydrophilicity and corrosion resistance in the simulated body fluid. The osteoblast cells grow and spread actively on the coated samples and the proliferation numbers and alkaline phosphate activities of the cells improve significantly compared to the uncoated Ti. It is suggested that the micro/nano-fibrous brushite coating can be a potential approach to improve the osteoinductivity and osteoconductivity of Ti implant, due to its similarity in morphology and dimension to inorganic components of biological hard tissues, and favorable responses to the osteoblasts.

Staphylococcus aureus can adhere to most foreign materials and form biofilm on the surface of medical devices. Biofilm infections are difficult to resolve. The goal of this in vitro study was to explore the use of chitosan-coated nanoparticles to prevent biofilm formation. For this purpose, S. aureus was seeded in 96-well plates to incubate with chitosan-coated iron oxide nanoparticles in order to study the efficiency of biofilm formation inhibition. The biofilm bacteria count was determined using the spread plate method; biomass formation was measured using the crystal violet staining method. Confocal laser scanning microscopy and scanning electron microscopy were used to study the biofilm formation. The results showed decreased viable bacteria numbers and biomass formation when incubated with chitosan-coated iron oxide nanoparticles at all test concentrations. Confocal laser scanning microscopy showed increased dead bacteria and thinner biofilm when incubated with nanoparticles at a concentration of 500 µg/mL. Scanning electron microscopy revealed that chitosan-coated iron oxide nanoparticles inhibited biofilm formation in polystyrene plates. Future studies should be performed to study these nanoparticles for anti-infective use.

To enhance the osteointegration and antibacterial property of titanium (Ti) implant, zinc calcium phosphate chemical conversion (Zn-Ca-PCC) was fabricated on pure Ti by phosphate chemical conversion technique. The surface of the coating was verified by combined techniques of scanning electron microscopy, energy-dispersive X-ray spectrometry, atomic force microscopy and water contact angle measurements. Plate-like Zn-Ca-PCC coatings are built up on the surface of Ti. The results obtained from the antibacterial studies suggest that the Zn-Ca-PCC coatings can greatly inhibit the growth of both Gram-positive ( Staphylococcus aureus ) and Gram-negative ( Pseudomonas aeruginosa ) bacteria. Moreover, the in vitro evaluations demonstrate that the adhesion, proliferation and differentiation of osteoblasts on Zn-Ca-PCC coatings were significantly enhanced compared with pure Ti. In conclusion, innovative Zn-Ca-PCC coatings on Ti with excellent antibacterial activity and biocompatibility are promising candidates for orthopedic and dental implants.

Acute exacerbation of chronic obstructive pulmonary disease (AECOPD) is an acute event characterized by the worsening of a patient's respiratory symptoms. To the best of our knowledge, few studies have investigated the computed tomography (CT) manifestation of AECOPD. Thus, the aim of the present study was to examine the CT manifestations during AECOPD. In total, 40 patients with AECOPD admitted to the emergency department were enrolled. CT images obtained at the time of exacerbation and at the 3-month follow-up were paired. Clinical characteristics and routine blood test results were also recorded. Airway dimensions and attenuation per patient were quantified from the 3rd to the 6th generation of four bronchi by Airway Inspector Slicer 2.8. The emphysema extent was also quantified and lung infiltration was detected, classified and measured. The CT images showed an increased wall area percentage (WA%) and increased mean and peak wall attenuation during the AECOPD; however, the extent of emphysema did not change significantly. In total, 60% of AECOPD patients presented with lung infiltration, compared with those at the follow-up CT scanning. The presence and extent of segmental distribution consolidation was correlated with the neutrophil percentage (N%), with a statistically significant difference observed. The total volume of lung parenchymal infiltration was correlated with the white blood cell (WBC) count and N%; however, no significant correlations were detected between the presence or extent of acinar shadow, air space consolidation with lobular distribution, ground-glass attenuation with lobular distribution, thickening of the interlobular septa and signs of infection (including the number of main symptoms, body temperature, WBC count and N%). The WA%, mean wall attenuation and peak wall attenuation increased during AECOPD, but the emphysema extent was unchanged. Lung infiltration existed frequently; however, only consolidation with segmental distribution appeared to be associated with bacterial infection.

Background Implantation-associated infections have increased significantly with the recent widespread use of medical implants. Treatments for these infections are not always successful because these infections are sometimes caused by multiantibiotic-resistant organisms. It is therefore particularly urgent to provide doctors with more effective antimicrobial agents against these antibiotic-resistant organisms. Human β-defensin 3 (hBD-3) has been shown to have strong broad-spectrum antibacterial activity. However, its effect on methicillin-resistant Staphylococcus epidermidis (MRSE) and methicillin-resistant Staphylococcus aureus (MRSA) in medical implant biofilm formation has not been reported. Methods In this study, we evaluated the effects of hBD-3 on S epidermidis ATCC 35984 (methicillin-resistant strain), MRSE287, and MRSA (ATCC43300) by evaluating bacterial adhesion, biofilm formation, and maturation. In addition, we used the spread plate method, confocal laser scanning microscopy, scanning electron microscopy, and real-time polymerase chain reaction to evaluate the effect of hBD-3. Results After evaluating biofilm adhesion and formation, we found that the number of each strain on the titanium surface was decreased in those groups exposed to 1MIC (minimum inhibitory concentration) of hBD-3 and was significantly lower than the number of colonies of the control. In the initial maturation of the biofilm, the numbers of each strain on the titanium surface from the 2MIC to 6MIC groups were significantly lower than the control. When the concentrations were further increased, hBD-3 was significantly effective against drug-resistant bacteria from the biofilms. Conclusions HBD-3 has the potential to eliminate the biofilm formation of Staphylococcus , especially antibiotic-resistant strains, effectively.

The impact of patellar denervation with electrocautery in total knee arthroplasty (TKA) on post-operative outcomes has been under debate. This study aims to conduct a meta-analysis and systematic review to compare the benefits and risks of circumpatellar electrocautery with those of non-electrocautery in primary TKAs. Comparative and randomized clinical studies were identified by conducting an electronic search of articles dated up to September 2012 in PubMed, EMBASE, Scopus, and the Cochrane databases. Six studies that focus on a total of 849 knees were analysed. A random-effects model was conducted using the inverse-variance method for continuous variables and the Mantel–Haenszel method for dichotomous variables. There was no significant difference in the incidence of anterior knee pain between the electrocautery and non-electrocautery groups. In term of patellar score and Knee Society Score, circumpatellar electrocautery improved clinical outcomes compared with non-electrocautery in TKAs. The statistical differences were in favour of the electrocautery group but have minimal clinical significance. In addition, the overall complications indicate no statistical significance between the two groups. This study shows no strong evidence either for or against electrocautery compared with non-electrocautery in TKAs. Therapeutic study (systematic review and meta-analysis), Level III.

Controversy exists regarding the clinical and radiological differences in outcomes between fixed-bearing (FB) and mobile-bearing (MB) total knee arthroplasties (TKAs) at the mid- or long-term follow-up. We therefore conducted a meta-analysis and systematic review of randomized controlled trials (RCTs) that have evaluated FB and MB TKAs. We searched the Cochrane Central Register of Controlled Trials (CENTRAL) in the Cochrane Library, Medline and Embase. The data, including demographic information, methodological quality, duration of follow-up, clinical and radiographical outcomes, patient preferences and complications, were extracted. The methodological quality of the studies was assessed in accordance with the guidelines presented in the Cochrane Handbook for Systematic Reviews of Interventions. Nine trials, studying 1,821 knees, were eligible for data extraction and meta-analysis. The Knee Society score and the maximum knee flexion demonstrated no difference between the FB and MB groups (P=0.47 and P=0.72, respectively). Similarly, no difference was revealed between the groups for radiological outcomes or general health results. An increased number of high-quality RCTs with long-term follow-ups are required to validate the results.

Mammalian β-defensins are small cationic peptides of approximately 2-6 kDa that have been implicated in mediating innate immune defenses against microbial infection. Previous studies have reported that mouse β-defensin-14 (MBD‑14), based on structural and functional similarities, appears to be an ortholog of human β-defensin-3 (HBD-3). The aim of this study was to identify the signaling pathways that contribute to the expression of MBD-14 in mouse osteoblasts (OBs) upon contact with methicillin-resistant Staphylococcus aureus (S. aureus) supernatant (SAS) to provide a theoretical basis for the use of MDB-14 as a therapeutic agent in the treatment of intramedullary infection with S. aureus in vivo. The bacterial exoproducts released by S. aureus mainly include a large amount of enterotoxins. Using mouse OBs, the release and regulation of MBD-14 was evaluated by real-time polymerase chain reaction (PCR) and enzyme‑linked immunosorbent assay (ELISA) following exposure to SAS. The activation of the p38 mitogen‑activated protein kinase (MAPK), extracellular signal-regulated kinase (ERK) and nuclear factor-κB (NF-κB) pathways was determined by western blot analysis. OBs treated with lipopolysaccharide (LPS) were used as the positive control. The results revealed that SAS significantly promoted the phosphorylation of p38 MAPK, NF-κB and the inhibitory subunit of NF-κBα (IκBα) in a time-dependent manner. The treatment of OBs with SB203580 (an inhibitor of p38 MAPK) and pyrrolidine dithiocarbamate (PDTC, an inhibitor of NF-κB) prior to stimulation with SAS significantly inhibited the phosphorylation and mRNA expression of p38 MAPK and NF-κB p65, simultaneously reducing the release of MBD-14. Our findings suggest that the release of MBD-14 is mediated at least in part through the activation of p38 MAPK and NF-κB in response to S. aureus‑secreted bacterial exoproducts. Moreover, our data demonstrate the innate immune capacity of OBs under conditions of bacterial challenge to enhance the local expression of this MBD-14, a peptide with anti‑staphylococcal activity.

A novel β type Ti35Nb2Ta3Zr alloy with low modulus (48 GPa) was fabricated using vacuum consumable arc melting. The corrosion resistance and cytotoxicity of Ti35Nb2Ta3Zr were evaluated. The open circuit potential, electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization methods were used to determine the corrosion resistance. In Ringer's solution, Ti35Nb2Ta3Zr alloy exhibits better corrosion resistance, as compared to that of Ti6Al4V and Ti. The cytotoxicity tests indicate that the biocompatibility of Ti35Nb2Ta3Zr is as good as Ti and Ti6Al4V which are widely used in biomedical fields. Based on corrosion resistance and cytotoxicity, the novel β type Ti35Nb2Ta3Zr alloy can be considered as a potential biomaterial.

An ongoing controversy exists on whether mobile-bearing design is superior over fixed-bearing design in unicondylar knee arthroplasties (UKAs). The present study conducted a systematic review to ascertain differences in performance between fixed- and mobile-bearing designs in UKAs. A literature search was performed in PubMed, Embase, Scopus and the Cochrane Library. A total of 9 comparative studies involving 915 knees comparing outcomes of mobile-bearing UKAs with fixed-bearing UKAs were included in the current analysis. Outcomes of interest included knee function, quality of life, radiographic outcomes, reasons and incidence of reoperation, timing of failures, and survivorship. The results presented no significant differences between the two designs in terms of knee scores, range of motion, limb alignment, implant positioning, incidence of radiolucent lines and overall reoperation rates. However, their differences have been noted in their modes and timing of failures. Early failures are related to the risk of bearing dislocation in the mobile-bearing design. In contrast, later failures are related to the risk of polyethylene wear in the fixed-bearing design. The available evidence has not confirmed the advantage of mobile-bearing UKAs over fixed-bearing UKAs but pointed out specific modes of failure. Therapeutic study (systematic review and meta-analysis), Level III.

Yongyuan Guo,1,* Beibei Hu,2,* Chu Tang,1 Yunpeng Wu,1 Pengfei Sun,1 Xianlong Zhang,3 YuhuaJia1 1Orthopaedic Department, 2Medical Examination Center, Qilu Hospital of Shandong University, Jinan, 3Orthopaedic Department, The Sixth Affiliated People’s Hospital, Medical School ofShanghai Jiao Tong University, Shanghai, People’s Republic of China *These authors contributed equally tothis work Abstract: Surface topography has significant influence on good and fast osseointegration of biomedical implants. In this work, ultrasonic shot peening was conducted to modify titanium to produce nanograined (NG) surface. Its ability to induce new bone formation was evaluated using an in vivo animal model. We demonstrated that the NG surface enhanced osteoblast adhesion, proliferation, differentiation, and mineralization in in vitro experiments compared to coarse-grained titanium surface. Push-out test, histological observations, fluorescent labeling, and histomorphometrical analysis consistently indicated that the NG surfaces developed have the higher osseointegration than coarse-grained surfaces. Those results suggest that ultrasonic shot peening has the potential for future use as a surface modification method in biomedical application. Keywords: ultrasonic shot peening, titanium, in vivo, osseointegeration

The infection of orthopedic implantation devices with Staphylococcus is a serious concern within the biomaterial community. Treatments are not always successful because of antibiotic-resistant bacteria and serious biofilm infections. Human β-defensin 3 (hBD-3) is considered to be the most promising class of defensin antimicrobial peptides and its effect on antibiotic-resistant Staphylococcus biofilms, combined with ultrasound (US)-targeted microbubble (MB) destruction (UTMD), has not been reported. In the study, we found that biofilm densities, the percentage of live cells and the viable counts of two tested Staphylococcus recovered from the biofilm were significantly decreased in the maximum concentration hBD-3 combined with UTMD compared with those of any other groups. Furthermore, results suggested that UTMD could also enhance 1MIC hBD-3 activity inhibiting the biofilm-associated genes expression of icaAD and the methicillin-resistance genes expression of MecA by simultaneously promoting the icaR expression. UTMD may have great potential for improving antibiotic activity against biofilm infections.

Titanium (Ti) alloys of the β-type are highly attractive metallic materials for biomedical applications due to their low elastic modulus, high corrosion resistance and notable biocompatibility. A new β-type Ti35Nb2Ta3Zr alloy with a low Young's modulus of approximately 48 GPa was previously fabricated. In the present study, the biocompatibility of this alloy was evaluated. In an in vitro assay, the Ti35Nb2Ta3Zr alloy did not markedly affect the adhesion of MG63 osteoblast cells, but it increased their proliferation, alkaline phosphatase (ALP) activity, calcium deposition and mRNA expression of osteogenic genes (i.e., ALP, osteocalcin, osteopontin). In an in vivo study, no marked histological differences were observed between the new bone formed on the surface of Ti35Nb2Ta3Zr and that formed on the surface of control Ti6Al4V rods placed in the medullary canal of rabbit femurs. Additionally, no significant differences were observed in the failure load of Ti35Nb2Ta3Zr and Ti6Al4V in pull-out tests. In conclusion, the Ti35Nb2Ta3Zr alloy with a lower elastic modulus closer to that of human bone has significant bone tissue compatibility equal to that of Ti6Al4V, which has been widely used in orthopedic applications.

Si-Feng Shi,1 Jing-Fu Jia,2 Xiao-Kui Guo,3 Ya-Ping Zhao,2 De-Sheng Chen,1 Yong-Yuan Guo,1 Tao Cheng,1 Xian-Long Zhang11Department of Orthopedic Surgery, Shanghai Sixth People’s Hospital, School of Medicine, 2School of Chemistry and Chemical Technology, 3Department of Medical Microbiology and Parasitology, School of Medicine, Shanghai Jiao Tong University Shanghai, ChinaBackground: Bone disorders (including osteoporosis, loosening of a prosthesis, and bone infections) are of great concern to the medical community and are difficult to cure. Therapies are available to treat such diseases, but all have drawbacks and are not specifically targeted to the site of disease. Chitosan is widely used in the biomedical community, including for orthopedic applications. The aim of the present study was to coat chitosan onto iron oxide nanoparticles and to determine its effect on the proliferation and differentiation of osteoblasts.Methods: Nanoparticles were characterized using transmission electron microscopy, dynamic light scattering, x-ray diffraction, zeta potential, and vibrating sample magnetometry. Uptake of nanoparticles by osteoblasts was studied by transmission electron microscopy and Prussian blue staining. Viability and proliferation of osteoblasts were measured in the presence of uncoated iron oxide magnetic nanoparticles or those coated with chitosan. Lactate dehydrogenase, alkaline phosphatase, total protein synthesis, and extracellular calcium deposition was studied in the presence of the nanoparticles.Results: Chitosan-coated iron oxide nanoparticles enhanced osteoblast proliferation, decreased cell membrane damage, and promoted cell differentiation, as indicated by an increase in alkaline phosphatase and extracellular calcium deposition. Chitosan-coated iron oxide nanoparticles showed good compatibility with osteoblasts.Conclusion: Further research is necessary to optimize magnetic nanoparticles for the treatment of bone disease.Keywords: chitosan-coated iron oxide, magnetic nanoparticles, osteoblasts

Magnetic nanoparticles have been widely used for tissue repair, magnetic resonance imaging, immunoassays and drug delivery. They are very promising in orthopaedic applications and several magnetic nanoparticles have been exploited for the treatment of orthopaedic disease. Here, we conducted an in vitro study to examine the interaction of magnetic iron oxide nanoparticles with human osteoblasts to evaluate the dose-related toxicity of the nanoparticles on osteoblasts. A transmission electron microscope was used to visualise the internalised magnetic nanoparticles in osteoblasts. The CCK-8 results revealed increased cell viability (107.5 % vitality compared with the control group) when co-cultured at a low concentration (20 μg/mL) and decreased cell viability (59.5 % vitality in a concentration of 300 μg/mL and 25.9 % in 500 μg/mL) when co-cultured in high concentrations. The flow cytometric detection revealed similar results with 5.48 % of apoptosis in a concentration of 20 μg/mL, 23.40 % of apoptosis in a concentration of 300 μg/mL and 28.49 % in a concentration of 500 μg/mL. The disrupted cytoskeleton of osteoblasts was also revealed using a laser scanning confocal microscope. We concluded that use of a low concentration of magnetic iron oxide nanoparticles is important to avoid damage to osteoblasts.

Staphylococcus aureus (S. aureus) is the principle causative agent of osteomyelitis, accounting for 80% of all human cases. S. aureus internalized in osteoblasts escapes immune response, including engulfment by phagocytes. It also escapes the action of a number of antibiotics. Ultrasound increases cell membrane permeability to a number of drugs. Following an internalization assay, we used low-frequency, low-power ultrasound combined with the antibiotic rifampin to target S. aureus internalized in human osteoblasts. Tryptic soy agar (TSA) was used to quantitate the antibacterial effect of rifampin combined with low-frequency ultrasound. A Cell Counting Kit-8 (CCK-8) assay was used to evaluate cell viability following exposure to ultrasound. Our data revealed that rifampin successfully penetrates into osteoblasts and kills internalized S. aureus in osteoblasts, while low-frequency ultrasound promotes this process. Ultrasound had a negative impact on the cell viability of osteoblasts; however, this damage was slight and reversible. Ultrasound-enhanced antibiotic efficiency to bacteria internalized in the osteoblasts may contribute to the control of chronic infection to reduce recurrence.

β type titanium alloys have attracted much attention in the biomedical field because they consist of non-cytotoxic elements, show high corrosion resistance, and are biologically compatible. In this study, a novel β type titanium alloy (Ti35Nb3Zr2Ta) with a Young's modulus of 48 GPa was fabricated and the alloy's corrosion resistance and in vitro response were determined. The results indicate that the novel alloy exhibits comparable corrosion resistance when compared with Ti6Al4V, but in vitro experiments show that osteoblasts attach, spread, proliferate, and differentiate better on Ti35Nb2Ta3Zr than on Ti6Al4V. The high corrosion resistance and satisfactory biocompatibility make the novel Ti35Nb3Zr2Ta alloy a promising biomaterial for surgical implants.