[Application of LU-tarjet congruent-arc technique in treatment of recurrent shoulder dislocation with huge glenoid defect].

Objective: To investigate the early effectiveness of the limited unique coracoid osteotomy suture button fixation Latarjet (LU-tarjet)-congruent-arc (CA) technique (LU-tarjet-CA) in treating recurrent shoulder dislocations with huge glenoid defect. Methods: The clinical data of 12 patients with recurrent shoulder dislocation and huge glenoid defect who met the selection criteria and treated with arthroscopic LU-tarjet-CA between January 2021 and December 2023 were retrospectively analyzed. The cohort included 8 males and 4 females, aged 20-40 years with an average age of 30.4 years. The range of glenoid bone loss was 30%-40%, with an average of 35.5%. The time from symptom onset to hospital admission ranged from 1 to 36 months, with an average of 18.5 months. The University of California Los Angeles (UCLA) score, American Association for Shoulder and Elbow Surgery (ASES) score, Walch-Duplay score, and Rowe score were used to evaluate shoulder function preoperatively and at 3, 6, and 12 months postoperatively. CT three-dimensional (3D) reconstruction was used to assess coracoid healing and plasticity at 3, 6, and 12 months postoperatively. Subjective satisfaction of patient was recorded at last follow-up. Results: All incisions healed by first intention, with no incision infection or nerve injury. All 12 patients were followed up 12 months. One patient developed Propionibacterium acnes infection within the joint postoperatively and recovered after initial arthroscopic debridement and anti-inflammatory treatment. At 3 months after operation, CT 3D-reconstruction showed 1 case of complete coracoid absorption; neither of these two patients experienced redislocation. The remaining patients exhibited partial coracoid absorption but displayed local reshaping, filling the preoperative defect area, and bony fusion between the coracoid and the glenoid. At last follow-up, 9 patients (75%) were very satisfied with the outcome, and 3 patients (25%) were satisfied; the satisfied patients experienced postoperative shoulder stiffness caused by suboptimal functional exercise but did not have impaired daily life activities. The UCLA score, ASES score, Walch-Duplay score, and Rowe score at 3, 6, and 12 months postoperatively were significantly better than preoperative scores, and each score improved further over time postoperatively, with significant differences between different time points ( P<0.05). Conclusion: The arthroscopic LU-tarjet-CA technique for treating recurrent shoulder dislocations with huge glenoid defect can achieve the surgical objective of bony blockade and filling bone defects to prevent shoulder dislocation, thereby improving patients' quality of life and shoulder joint function and stability.

Esculin suppresses the PERK-eIF2α-CHOP pathway by enhancing SIRT1 expression in oxidative stress-induced rat chondrocytes, mitigating osteoarthritis progression in a rat model.

OBJECTIVE: Osteoarthritis (OA) is a degenerative disease characterized by the gradual degeneration of chondrocytes, involving endoplasmic reticulum (ER) stress. Esculin is a natural compound with antioxidant, anti-inflammatory and anti-tumor properties. However, its impact on ER stress in OA therapy has not been thoroughly investigated. We aim to determine the efficiency of Esculin in OA treatment and its underlying mechanism. METHODS: We utilized the tert-butyl hydroperoxide (TBHP) to establish OA model in chondrocytes. The expression of SIRT1, PERK/eIF2α pathway-related proteins, apoptosis-associated proteins and ER stress-related proteins were detected by Western blot and Real-time PCR. The apoptosis was evaluated by flow cytometry and terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL) staining. X-ray imaging, Hematoxylin & Eosin staining, Safranin O staining and immunohistochemistry were used to assess the pharmacological effects of Esculin in the anterior cruciate ligament transection (ACLT) rat OA model. RESULTS: Esculin downregulated the expression of PERK/eIF2α pathway-related proteins, apoptosis-associated proteins and ER stress-related proteins, while upregulated the expression of SIRT1 and Bcl2 in the TBHP-induced OA model in vitro. It was coincident with the results of TUNEL staining and flow cytometry. We further confirmed the protective effect of Esculin in the rat ACLT-related model. CONCLUSION: Our results suggest the potential therapeutic value of Esculin on osteoarthritis. It probably inhibits the PERK-eIF2α-ATF4-CHOP pathway by upregulating SIRT1, thereby mitigating endoplasmic reticulum stress and protecting chondrocytes from apoptosis.

Catalpol antagonizes LPS-mediated inflammation and promotes osteoblast differentiation through the miR-124-3p/DNMT3b/TRAF6 axis.

BACKGROUND: Dysregulated inflammation and osteoblast differentiation are implicated in osteoporosis. Exploring the activity of catalpol in inflammation and osteoblast differentiation deepens the understanding of osteoporosis pathogenesis. METHODS: LPS was used to treated hFOB1.19 cells to induce inflammation and repress osteoblast differentiation. FOB1.19 cells were induced in osteoblast differentiation medium and treated with LPS and catalpol. Cell viability was assessed using CCK-8. ALP and Alizarin red S staining were conducted for analyzing osteoblast differentiation. The levels of IL-1ß, TNF-α and IL-6 were examined by ELISA. The methylation of TRAF6 promoter was examined through MS-PCR. The binding of miR-124-3p to DNMT3b and DNMT3b to TRAF6 promoter was determined with dual luciferase reporter and ChIP assays. RESULTS: LPS enhanced secretion of inflammatory cytokines and suppressed osteoblast differentiation. MiR-124-3p and TRAF6 were upregulated and DNMT3b was downregulated in LPS-induced hFOB1.19 cells. Catalpol protected hFOB1.19 cells against LPS via inhibiting inflammation and promoting osteoblast differentiation. MiR-124-3p targeted DNMT3b, and its overexpression abrogated catalpol-mediated protection in LPS-treated hFOB1.19 cells. In addition, DNMT3b methylated TRAF6 promoter to restrain its expression. Catalpol exerted protective effects through suppression of the miR-124-3p/DNMT3b/TRAF6 axis in hFOB1.19 cells. CONCLUSION: Catalpol antagonizes LPS-mediated inflammation and suppressive osteoblast differentiation via controlling the miR-124-3p/DNMT3b/TRAF6 axis.

Learning curve analysis of robotic-assisted total knee arthroplasty with a Chinese surgical system.

PURPOSE: The aim of this study was to analyze the learning curve of total operative time, bone cutting accuracy, and limb alignment in total knee arthroplasty (TKA) using a Chinese image-based knee surgery robot known as HURWA. Additionally, a comparison was conducted with conventional TKA to ascertain the benefits of robotic-assisted TKA. METHODS: In this retrospective study, we analyzed a series of patients (n = 90) who underwent robotic-assisted total knee arthroplasty using the HURWA robot between December 2021 and October 2022. The procedures were performed by one of three orthopedic surgeons with varying levels of experience. As a control group, we selected the last 30 conventional TKA cases performed by each of these three surgeons. To determine the learning curve, we recorded the operative time, bone cutting error, and pre- and post-surgery radiographs. RESULTS: The study found no significant differences in total operative time, bone cutting accuracy, or limb alignment among the three surgeons. Of the three surgeons, surgeon 1, who had the most experience in joint arthroplasty, reached the learning curve in case 8, with the shortest bone cutting time and robot time. Surgeon 2 reached the learning curve in case 16, while surgeon 3 reached the learning curve in case 9. There was no observable learning curve effect for bone cutting accuracy and limb alignment. However, the percentage of cases where limb alignment differed from preoperative planning by 3° or less was higher in robotic-assisted TKA (77.97%) than in conventional TKA (47.19%). CONCLUSION: The study determined that the learning curve for robotic-assisted TKA using the HURWA knee surgery robot ranged from 8 to 20 cases. No observable learning curve effect was detected for bone cutting accuracy or limb alignment. Experienced surgeons using the HURWA robot for bone cutting took less time and reached the learning curve earlier. The HURWA robot achieved better limb alignment without depending on the experience of conventional TKA.

BMP2 induces osteogenic differentiation through ACKR3 in mesenchymal stem cells.

In recent years, bone loss related diseases have attracted more and more attention, such as osteoporosis and osteonecrosis of the femoral head exhibited symptoms of osteopenia or insufficient bone mass in a certain stage. Mesenchymal stem cells (MSCs), which can be induced to differentiate into osteoblasts under certain conditions can provide a new solution bone disease. Herein, we deciphered the possible mechanism by which BMP2 drives the transduction of MSCs to the osteoblast lineage through ACKR3/p38/MAPK signaling. The levels of ACKR3 in femoral tissues of samples from humans with different ages and sexes were measured firstly and found that ACKR3 protein levels increase with age. In vitro cellular assays showed that ACKR3 inhibits BMP2-induced osteo-differentiation and promotes adipo-differentiation of MSCs, whereas siACKR3 exhibited the opposite effects. In vitro embryo femur culture experiment showed that inhibition of ACKR3 enhanced BMP2-induced trabecular bone formation in C57BL6/J mouse. In terms of molecular mechanisms, we found that p38/MAPK signaling might play the key role. ACKR3 agonist TC14012 suppressed the phosphorylation of p38 and STAT3 in BMP2 induced MSCs differentiation. Our findings suggested that ACKR3 might be a novel therapeutic target for the treatment of bone-associated diseases and bone-tissue engineering.

Effect of Low-Intensity Pulsed Ultrasound on the Graft-Bone Healing of Artificial Ligaments: An In Vitro and In Vivo Study.

BACKGROUND: As many researchers have focused on promoting the graft-bone healing of artificial ligaments, even with numerous chemical coatings, identifying a biosafe, effective, and immediately usable method is still important clinically. PURPOSE: (1) To determine whether a low-intensity pulsed ultrasound system (LIPUS) promotes in vitro cell viability and osteogenic differentiation and (2) to assess the applicability and effectiveness of LIPUS in promoting the graft-bone healing of artificial ligaments in vivo. STUDY DESIGN: Controlled laboratory study. METHODS: Polyethylene terephthalate (PET) sheets and grafts were randomly assigned to control and LIPUS groups. MC3T3-E1 preosteoblasts were cultured on PET sheets. Cell viability and morphology were evaluated using a live/dead viability assay and scanning electron microscopy. Alkaline phosphatase activity, calcium nodule formation, and Western blot were evaluated for osteogenic differentiation. For in vivo experiments, the effect of LIPUS was evaluated via an extra-articular graft-bone healing model in 48 rabbits: the osteointegration and new bone formation were tested by micro-computed tomography and histological staining, and the graft-bone bonding was tested by biomechanical testing. RESULTS: Cell viability was significantly higher in the LIPUS group as compared with control (living and dead compared between control and LIPUS groups, P = .0489 vs P = .0489). Better adherence of cells and greater development of extracellular matrix were observed in the LIPUS group. Furthermore, LIPUS promoted alkaline phosphatase activity, calcium nodule formation, and the protein expression of collagen 1 (P = .0002) and osteocalcin (P = .0006) in vitro. Micro-computed tomography revealed higher surrounding bone mass at 4 weeks and newly formed bone mass at 8 weeks in the LIPUS group (P = .0014 and P = .0018). Histological analysis showed a narrower interface and direct graft-bone contact in the LIPUS group; the surrounding bone area at 4 weeks and the mass of newly formed bone at 4 and 8 weeks in the LIPUS group were also significantly higher as compared with control (surrounding bone, P < .0001; newly formed bone, P = .0016 at 4 weeks and P = .005 at 8 weeks). The ultimate failure load in the LIPUS group was significantly higher than in the control group (P < .0001 at 4 weeks; P = .0008 at 8 weeks). CONCLUSION: LIPUS promoted the viability and osteogenic differentiation of MC3T3-E1 preosteoblasts in vitro and enhanced the graft-bone healing of PET artificial ligament in vivo. CLINICAL RELEVANCE: LIPUS is an effective physical stimulation to enhance graft-bone healing after artificial ligament implantation.

Accuracy of the Horizontal Calibrator in Correcting Leg Length and Restoring Femoral Offset in Total Hip Arthroplasty.

Background: Limb length discrepancy (LLD) is one of the most common postoperative complications and can cause serious consequences. Poor recovery of femoral offset (OD) will result in weakness of the patient's external rotator muscles and affect the patient's postoperative function. The study is aimed to present a simple approach that compensates for the shortcomings of previous measuring devices and combines the advantages of different measuring devices to provide more accurate limb length and femoral offset restoration in total hip arthroplasty (THA). Methods: This study was a prospective controlled trial involving 89 patients with THA. Group I (n = 44) was used for intraoperative measurement of THA with our self-designed horizontal calibrator. Group II (n = 45) was measured by a traditional freehand technique. The main outcome indicators were measured on the Neusoft PACS, including LLD, femoral offset deviation, and operative time. IBM SPSS 23.0 was used for data analysis. Results: The independent sample t-test was performed for all the data. The operative time, preoperative radiographic LLD, and OD of Group I and Group II had no statistical significance. Postoperative LLD of Group I and Group II were 2.5 ± 2.1 mm (range -5.7 to 8.3 mm) and 6.2 ± 4.3 mm (range -18.0 to 15.2 mm), and the independent sample t-test data of both (P < 0.001; 95%CI = -5.1, -2.2) showed statistical significance. In Group I, there were 38 THAs with LLD <5 mm, accounting for 86% and there were 44 THAs with LLD <10 mm, accounting for 100%. In Group II, there were 20 THAs with LLD <5 mm, accounting for 44%. There were 36 THAs with LLD <10 mm, covering for 80%. There was no significant difference in postoperative femoral offset and OD. Conclusion: The horizontal calibrator can provide more accurate limb length and femoral offset recovery in THA. It is a simple surgical technique that does not add additionally surgical costs and does not significantly increase operative time, providing a new solution for surgeons to resolve postoperative LLD and restore femoral offset.

Effects of progressive resistance training for early postoperative fast-track total hip or knee arthroplasty: A systematic review and meta-analysis.

Progressive resistance training (PRT) is one of the most commonly used exercise methods after joint replacement, while its effectiveness and safety are still controversial. Therefore, it's vital to investigate the effect of PRT on muscle strength and functional capacity early postoperative total hip arthroplasty (THA) or total knee arthroplasty (TKA). Relevant studies were identified via a search of Medline, Web of science and Cochrane Library from 2002 to 12 May 2020. Fifteen of 704 studies which comprised 6 THAs and 8 TKAs, involving 1021 adult patients were eligible for inclusion in the meta-analysis. There were no significant differences between the two groups after TKA in the 6-min walk test (6-WMT) within 1 month (95% CI = -0.41, 1.53), within 3 months (95% CI = -0.27, 0.76), within 12 months (95% CI = -0.29, 0.66); climb performance in seconds (s) (SCP), leg extension power, timed up and go test in seconds (s) (TUG) within 1 month (95% CI = -1.75, 0.77), within 3 months (95% CI = -0.48, 0.33), within 12 months (95% CI = -0.44, 0.35), sit to stand, number of repetitions in 30s (ST). There was no difference in the incidence of adverse events (95% CI = -0.01, 0.10). Similarly, two groups were also no obvious distinction after THA in the 6-WMT, SCP, Leg extension power, ST. PRT early after THA or TKA did not differ significantly from SR in terms of functional capacity, muscle strength recovery and incidence of adverse events. PRT is one of the options for rapid rehabilitation after joint replacement.

Iron Overload Induces Apoptosis and Cytoprotective Autophagy Regulated by ROS Generation in Mc3t3-E1 Cells.

Iron overload has been found very common in diseases such as hereditary hemochromatosis, thalassemia, and sickle cell disease and in healthy postmenopausal women. Recent studies have shown that iron overload is considered an independent risk factor for osteoporosis. Studies have demonstrated that iron overload could induce apoptosis and inhibit viability in osteoblasts. However, the underlying mechanism still remains poorly understood. The purpose of the present study is to investigate possible mechanism of iron overload-induced apoptosis, and the roles autophagy and reactive oxygen species (ROS) played under iron overload conditions. Ferric ammonium citrate (FAC) (100-1600 µM) was utilized as iron donor to induce iron overload conditions. Intracellular iron concentration was measured using Iron Assay Kit. The viability was assessed by CCK-8 assay. Cell apoptosis was examined using Annexin V-FITC/PI staining with a flow cytometry, and levels of Bax, Bcl-2, cleaved caspase-3, and cleaved PARP were evaluated with Western blot. Cell autophagy was detected by evaluating LC3 with immunofluorescence and Western blot. The expressions of Beclin-1 and P62 were also assessed with Western blot. The intracellular ROS level was evaluated using a DCFH-DA probe with a flow cytometry, and NADPH oxidase 4 (Nox4) expressions were assessed with Western blot. Our results showed that FAC increased intracellular iron concentration and significantly inhibited cell viability. Furthermore, iron overload induced apoptosis and autophagy in osteoblast cells. What's more, pretreatment with autophagy inhibitor chloroquine (CQ) enhanced iron overload-induced osteoblast apoptosis via the activation of caspases. Moreover, iron overload increased ROS production and Nox4 expression. Inhibition of autophagy increased ROS production, and scavenging of ROS by antioxidant N-Acetyl-L-cysteine (NAC) inhibited caspases activity and rescued iron overload-induced apoptosis. These results suggested that autophagy exerted cytoprotective effect, and scavenging excessive intracellular ROS could be a novel approach for the treatment of iron overload-induced osteoporosis.

Mechanisms of Bone Remodeling Disorder in Hemophilia.

Hemophilia is caused by a lack of antihemophilic factor(s), for example, factor VIII (FVIII; hemophilia A) and factor IX (FIX; hemophilia B). Low bone mass is widely reported in epidemiological studies of hemophilia, and patients with hemophilia are at an increased risk of fracture. The detailed etiology of bone homeostasis imbalance in hemophilia is unclear. Clinical and experimental studies show that FVIII and FIX are involved in bone remodeling. However, it is likely that antihemophilic factors affect bone biology through thrombin pathways rather than via their own intrinsic properties. In addition, among patients with hemophilia, there are pathophysiological processes in several systems that might contribute to bone loss. This review summarizes studies on the association between hemophilia and bone remodeling, and might shed light on the challenges facing the care and prevention of osteoporosis and fracture in patients with hemophilia.

In vitro and in vivo evaluation of a ciprofloxacin delivery system based on poly(DLLA-co-GA-co-CL) for treatment of chronic osteomyelitis.

Chronic osteomyelitis causes serious injury to patients. Antibiotic delivery systems based on poly(lactide-co-glycolide) (PLGA) have great potential for treatment of chronic osteomyelitis. However, PLGA has a glass-transition temperature that is higher than physiological temperatures, resulting in a lack of flexibility for implantation into the bone marrow cavity. As an alternative, poly(d, l-lactide-co-glycolide-co-ε-caprolactone) (PLGC) presents good flexibility due to the introduction of poly(ε-caprolactone) segments. To develop a new strategy for treatment of chronic osteomyelitis, a ciprofloxacin delivery system was prepared using PLGC as carriers, the antibacterial effects of which were evaluated both in vivo and in vitro. The in vitro release behavior showed that the average release reached 268.5 µg/days on day 33, with a cumulative release rate of 56.01%. A bacteriostatic ring, with a diameter of 26.83 ± 0.83 mm, was produced by ciprofloxacin against Staphylococcus aureus after 30 days of release via our ciprofloxacin-PLGC system. After 4 weeks of treatment in vivo, chronic-osteomyelitis-model rats had a bodyweight of 385.83 ± 17.23 g and a normal white-blood-cell count, as well as a lower number of bacterial colonies per gram of bone tissue of (10.6 ± 3.0) × 101 CFU/g. Furthermore, no inflammatory cells were observed via hematoxylin-and-eosin staining, and normal bone structure was observed via X-ray. Taken together, our findings indicate that our novel ciprofloxacin-PLGC system yielded noteworthy antibacterial effects both in vitro and in vivo, suggesting that it may be useful for treating patients with chronic osteomyelitis.

A study on the mechanism of Wnt inhibitory factor 1 in osteoarthritis.

INTRODUCTION: In our study we aimed to investigate the mechanism of Wnt inhibitory factor 1 (WIF1) on regulating chondrocyte proliferation and apoptosis via reactive oxygen species (ROS) and the Wnt/ßcatenin signaling pathway in osteoarthritis (OA). MATERIAL AND METHODS: Osteoarthritis chondrocytes were treated with interleukin 1ß (IL-1ß) to simulate an inflammatory condition. Quantitative real-time polymerase chain reaction (qRT-PCR) and western blot were applied for detecting WIF1 expression in OA chondrocytes. MTT assay and flow cytometry were carried out to analyze the cell proliferation and apoptosis. Content of ROS was detected using flow cytometry, and activity of the Wnt/ßcatenin signaling pathway was detected using immunofluorescence, western blot and luciferase reporter assay. Western blot and enzyme-linked immunosorbent assay (ELISA) were performed to detect the expression of apoptosis-related proteins and secretion of matrix metalloproteinases (MMPs). RESULTS: WIF1 expression in OA chondrocytes was significantly lower than in normal chondrocytes. After WIF1 cDNA transfection, the aberrantly high ROS level in OA chondrocytes was down-regulated, which led to the increase of proliferation and reduction of apoptosis. The Wnt/ßcatenin signaling pathway was suppressed by WIF1 overexpression and the secretion of MMPs was therefore reduced. CONCLUSIONS: Up-regulation of WIF1 would promote proliferation and suppress apoptosis of OA chondrocytes through eliminating ROS production and reduce secretion of MMPs via blocking the Wnt/ßcatenin signaling pathway.

Hydrogen sulfide promotes lipopolysaccharide-induced apoptosis of osteoblasts by inhibiting the AKT/NF-κB signaling pathway.

Apoptosis of osteoblasts plays a crucial role in osteomyelitis. Hydrogen sulfide (H2S) levels are increased in the pathophysiological processes of osteomyelitis. However, the effect of H2S on the apoptosis of osteoblasts remains unclear. To investigate the specific role of H2S in osteoblast apoptosis, MC3T3-E1 and hFOB cells were treated with NaHS or Na2S, a donor of H2S, and lipopolysaccharide (LPS), during osteomyelitis. 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assays, flow cytometry analysis, western blotting, immunofluorescence, polymerase chain reaction, and Alizarin red staining were performed to examine the effects of H2S on osteoblast cell apoptosis, cell osteogenic differentiation, and AKT kinase (AKT)/nuclear factor kappa B (NF-κB) signaling. Hydrogen sulfide increased cell apoptosis, and inhibited the proliferation and osteogenic differentiation of osteoblast cells impaired by LPS. H2S increased apoptosis through upregulation of the FAS ligand (FASL) signaling pathway. H2S-induced apoptosis was alleviated using a FAS/FASL signaling pathway inhibitor. Treatment with NaHS also increased cell apoptosis by downregulating AKT/NF-κB signaling. In addition, treatment with an AKT signaling pathway activator decreased apoptosis and reversed the inhibitory effects of H2S on osteogenic differentiation. Hydrogen sulfide promotes LPS-induced apoptosis of osteoblast cells by inhibiting AKT/NF-κB signaling.

Biocompatibility evaluation of antibacterial Ti-Ag alloys with nanotubular coatings.

BACKGROUND: Implant-related infection is a major problem postsurgery. As an alternative to a localized antibiotic release system, we used Ag to fabricate Ti-Ag alloys with nanotubular coatings (TiAg-NTs). Ag has excellent antibacterial properties, but its biological toxicity is a concern. Therefore, we performed biological experiments both in vitro and in vivo to evaluate the biocompatibility of TiAg-NTs with different concentrations of Ag (1%, 2%, and 4%). METHODS: For in vitro experiments, cytocompatibility, including cell attachment, viability, and proliferation, was tested, and genes and proteins related to osteogenic differentiation were also evaluated. For in vivo assays, the rat femoral condylar insertion model was used, and micro-computed tomography (micro-CT) and histological analysis were conducted to analyze bone formation around implants at 1, 2, and 4 weeks after surgery. RESULTS: Both in vitro and in vivo results indicate that Ti2%Ag-NT showed comparable cytocompatibility with commercially pure Ti (cp-Ti), and it could achieve good osseointegration with the surrounding bone tissue. CONCLUSION: We thus believe that Ti2%Ag-NT is a potential biomaterial for orthopedics.

Antibacterial activities and biocompatibilities of Ti-Ag alloys prepared by spark plasma sintering and acid etching.

In this work, Ti-Ag sintered alloys (Ti-Ag) with different Ag contents were prepared by a spark plasma sintering (SPS) technique, which is a new, efficient and convenient method of powder metallurgy. The Ti-Ag samples were then treated with a mixture of 40 wt% hydrofluoric acid (HF) and nitric acid (HNO3). The surface features, ion release, antibacterial activities and biocompatibilities of the acid-etched Ti-Ag (Ti-Ag(AE)) samples were systematically characterized. The surface characterization results revealed the formation of micropits and particles with high Ag contents. Antibacterial experiments demonstrated that the antibacterial ratios of the Ti-Ag samples increased significantly after the acid etching treatment, and the particles with high Ag contents are thought to play a key role in the antibacterial mechanism. Biocompatibility experiments indicated that the cell proliferation, cell morphology, and osteoblastic differentiation did not significantly differ between the pure titanium (cp-Ti) and Ti-Ag(AE) samples. The Ti-Ag(AE) samples with 3 wt% and 5 wt% Ag not only possessed sustained antibacterial activities for at least 30 days but also did not have impaired biocompatibility.

Strontium ranelate-induced anti-adipocytic effects are involved in negative regulation of autophagy in rat bone marrow mesenchymal stem cells.

PURPOSES: Strontium ranelate (SrRN) is a novel and effective anti-osteoporotic drug used to promote bone formation and restrain bone resorption. However, studies of the effects and mechanism of SrRN on adipocytic differentiation from bone marrow mesenchymal stem cells (BMMSCs) remain limited. METHODS: The cytoactivity of BMMSCs was analyzed by CCK-8 and annexin V-FITC/PI kit. Then the differentiation efficiency was analyzed by Oil Red O staining and western blotting. The level of autophagy was evaluated by immunofluorescence and western blotting. The autophagy inhibitor chloroquine and the selective Akt antagonist API-2 were used to study the relationship between autophagy regulation and adipocytic differentiation. Finally variations in ß-catenin protein levels were also analyzed by western blotting, as were proteins related with autophagy and differentiation signaling pathways. RESULTS: SrRN had no influence on the vatility of BMMSCs (bone marrow mesenchymal stem cells) and exhibited anti-adipocytic effects in dose-dependent manner. At the early stage of adipocytic differentiation, autophagy level significantly increased and SrRN inhibited the variation tendency. Then we detected the PPAR-γ and ß-catenin variation when applied with autophagy inhibitor CQ (chloroquine) and the same way, after Akt selective inhibitor applied in the test, the effect of SrRN was compromised. At last, we detected the increased phosphorylation of Akt-related pathway at 1.00 mM concentration of SrRN in comparison with the adipocytic induction. CONCLUSIONS: SrRN could disturb the process of adipocytic differentiation of BMMSCs and interfere with the variation tendency of autophagy level after adipocytic induction in Akt-dependent manners.

MiR-338-5p Promotes Inflammatory Response of Fibroblast-Like Synoviocytes in Rheumatoid Arthritis via Targeting SPRY1.

Our purpose is to study the roles of microRNA-338-5p (miR-338-5p) on the proliferation, invasion, and inflammatory response of fibroblast-like synoviocytes (SFs) in rheumatoid arthritis patients by regulating SPRY1. The target relationship between miR-338-5p and SPRY1 was validated through luciferase reporter system. The expression of miR-338-5p and SPRY1 in synovial tissues and synovial cells were detected using RT-PCR and western blot. The mimics and inhibitors of miR-338-5p were transfected into SFs. MTT, Transwell, and ELISA assays were used to analyze cell proliferation, invasiveness, and the secreted extracellular pro-inflammatory cytokines (such as IL-1a, IL-6, COX2) levels of SFs. MiR-338-5p was highly expressed in rheumatoid arthritis tissues and cells, and directly down-regulated the expression of SPRY1 in the SFs of rheumatoid arthritis patients. Cell proliferation, invasiveness and the expression level of pro-inflammatory cytokines in synovial cells increased after the transfection of miR-338-5p mimics, while the proliferation, invasion and expression level of pro-inflammatory cytokines decreased after the transfection of miR-338-5p inhibitors. In conclusion,miR-338-5p promoted the proliferation, invasion and inflammatory reaction in SFs of rheumatoid arthritis by directly down-regulating SPRY1 expression. J. Cell. Biochem. 118: 2295-2301, 2017. © 2017 Wiley Periodicals, Inc.

Antibacterial abilities and biocompatibilities of Ti-Ag alloys with nanotubular coatings.

PURPOSE: To endow implants with both short- and long-term antibacterial activities without impairing their biocompatibility, novel Ti-Ag alloy substrates with different proportions of Ag (1, 2, and 4 wt% Ag) were generated with nanotubular coverings (TiAg-NT). METHODS: Unlike commercial pure Ti and titania nanotube, the TiAg-NT samples exhibited short-term antibacterial activity against Staphylococcus aureus (S. aureus), as confirmed by scanning electron microscopy and double staining with SYTO 9 and propidium iodide. A film applicator coating assay and a zone of inhibition assay were performed to investigate the long-term antibacterial activities of the samples. The cellular viability and cytotoxicity were evaluated through a Cell Counting Kit-8 assay. Annexin V-FITC/propidium iodide double staining was used to assess the level of MG63 cell apoptosis on each sample. RESULTS: All of the TiAg-NT samples, particularly the nanotube-coated Ti-Ag alloy with 2 wt% Ag (Ti2%Ag-NT), could effectively inhibit bacterial adhesion and kill the majority of adhered S. aureus on the first day of culture. Additionally, the excellent antibacterial abilities exhibited by the TiAg-NT samples were sustained for at least 30 days. Although Ti2%Ag-NT had less biocompatibility than titania nanotube, its performance was satisfactory, as demonstrated by the higher cellular viability and lower cell apoptosis rate obtained with it compared with those achieved with commercial pure Ti. The Ti1%Ag-NT and Ti4%Ag-NT samples did not yield good cell viability. CONCLUSION: This study indicates that the TiAg-NT samples can prevent biofilm formation and maintain their antibacterial ability for at least 1 month. Ti2%Ag-NT exhibited better antibacterial ability and biocompatibility than commercial pure Ti, which could be attributed to the synergistic effect of the presence of Ag (2 wt%) and the morphology of the nanotubes. Ti2%Ag-NT may offer a potential implant material that is capable of preventing implant-related infection.