Based on molecular docking and real-time PCR technology, the two-component system Bae SR was investigated on the mechanism of drug resistance in CRAB.

This study aimed to explore the role of the two-component system Bae SR in the mechanism of drug resistance in carbapenem-resistant A. baumannii (CRAB) using molecular docking and real-time polymerase chain reaction (PCR). The two-component system Bae SR of Acinetobacter baumannii was subjected to molecular docking with imipenem, meropenem, and levofloxacin. Antibacterial assays and fluorescence quantitative PCR were used to explore protein-ligand interactions and molecular biological resistance mechanisms related to CRAB. The analysis of the two-component system in A. baumannii revealed that imipenem exhibited the highest docking energy in Bae S at - 5.81 kcal/mol, while the docking energy for meropenem was - 4.92 kcal/mol. For Bae R, imipenem had a maximum docking energy of - 4.28 kcal/mol, compared with - 4.60 kcal/mol for meropenem. The highest binding energies for Bae S-levofloxacin and Bae R-levofloxacin were - 3.60 and - 3.65 kcal/mol, respectively. All imipenem-resistant strains had minimum inhibitory concentration (MIC) values of 16 µg/mL, whereas levofloxacin-resistant strains had MIC values of 8 µg/mL. The time-sterilization curve showed a significant decrease in bacterial colony numbers at 2 h under the action of 8 µg/mL imipenem, indicating antibacterial effects. In contrast, levofloxacin did not exhibit any antibacterial activity. Fluorescence quantitative PCR results revealed significantly increased relative expression levels of bae S and bae R genes in the CRAB group, which were 2 and 1.5 times higher than those in the CSAB group, respectively, with statistically significant differences. Molecular docking in this study found that the combination of Bae SR and carbapenem antibiotics (imipenem, meropenem) exhibited stronger affinity and stability compared with levofloxacin. Moreover, the overexpression of the two-component system genes in carbapenem-resistant A. baumannii enhanced its resistance to carbapenem, providing theoretical and practical insights into carbapenem resistance in respiratory tract infections caused by A. baumannii.

LincRNA-EPS inhibits caspase-11 and NLRP3 inflammasomes in gingival fibroblasts to alleviate periodontal inflammation.

To investigate the effects of long intergenic noncoding RNA-erythroid prosurvival (lincRNA-EPS) on periodontal inflammation mediated by inflammasomes and to explore its mechanism. Experimental periodontitis was induced in KO (lincRNA-EPS-/- ) and WT (lincRNA-EPS+/+ ) mice to compare the periodontal bone loss and inflammation by using micro-computed tomography, immunofluorescence staining and haematoxylin and eosin staining. The expression and activation of cysteinyl aspartate-specific proteinase-11 (caspase-11) and NOD-like receptor protein 3 (NLRP3) inflammasomes, as well as nuclear factor-kappa B (NF-κB) activation in mouse gingival fibroblasts (MGFs), were measured by real-time quantitative polymerase chain reaction, Western blotting, enzyme-linked immunosorbent and lactate dehydrogenase assays. MGFs were transfected with overexpression plasmids to assess the biological functions of lincRNA-EPS. RNA pull-down and immunoprecipitation experiments were performed to identify the interacting protein of lincRNA-EPS. LincRNA-EPS-expressing lentivirus was locally administered to inflamed periodontal tissues to evaluate its salvage function in periodontitis. The absence of lincRNA-EPS increased bone loss and expression of myeloperoxidase, interleukin-1α (IL-1α) and IL-1ß in the inflammatory periodontium. LincRNA-EPS KO MGFs exhibited increased expression and activation of caspase-11/NLRP3 inflammasome components than WT MGFs under lipopolysaccharide (LPS) stimulation. The expression and activation of these molecules were inhibited in lincRNA-EPS overexpressed MGFs. Mechanistically, lincRNA-EPS directly bound to transactive response DNA-binding protein 43 (TDP43) in the nucleus of MGFs, and TDP43 knockdown exerted a similar inhibitory effect on NF-κB activation and the inflammasomes as lincRNA-EPS overexpression. Locally injecting lincRNA-EPS-expressing lentivirus weakened the periodontal damage. LincRNA-EPS inhibits the LPS-induced production and activation of caspase-11 and NLRP3 inflammasomes by suppressing the activation of the NF-κB signalling pathway via interacting with TDP43, thereby alleviating periodontitis.

A study on the appropriate dose of rocuronium for intraoperative neuromonitoring in Da Vinci robot thyroid surgery: a randomized, double-blind, controlled trial.

Background: This study was to explore the effect of different doses of rocuronium bromide on neuromonitoring during Da Vinci robot thyroid surgery. Methods: This was a prospective, randomized, double-blind, controlled trial that included 189 patients who underwent Da Vinci robot thyroidectomy with intraoperative neuromonitoring(IONM). Patients were randomly divided into three groups and given three different doses of rocuronium (0.3mg/kg, 0.6mg/kg, 0.9mg/kg). Outcome measurements included IONM evoked potential, postoperative Voice Handicap Index-30(VHI-30), intraoperative body movement incidence rate, Cooper score, and hemodynamic changes during anesthesia induction.Results: The difference in IONM evoked potentials at various time points between the three groups was not statistically significant (P>0.05). The difference in Cooper scores and intraoperative body movement incidence rate between 0.6 and 0.9mg/kg groups was statistically significant compared with the 0.3mg/kg group (both P<0.001). There was no statistically significant difference in VHI-30 score and hemodynamic changes during anesthesia induction among the three groups (both P>0.05). Conclusions: For patients undergoing Da Vinci robot thyroidectomy, a single dose of rocuronium at 0.6 and 0.9mg/kg during anesthesia induction can provide stable IONM evoked potential. Additionally, compared to 0.3 mg/kg, it can offer better tracheal intubation conditions and lower incidence of body movements during surgery. It is worth noting that the use of higher doses of rocuronium should be adjusted based on the duration of IONM and local practices.

Mesoporous TiO2 Coatings Regulate ZnO Nanoparticle Loading and Zn2+ Release on Titanium Dental Implants for Sustained Osteogenic and Antibacterial Activity.

Two major issues are currently hindering the clinical practice of titanium dental implants for the lack of biological activities: immediate/early loading risks and peri-implantitis. To solve these issues, it is urgent to develop multifunctional implants modified with effective osteogenic and antibacterial properties. Zinc oxide nanoparticles (ZnO NPs) possess superior antibacterial activity; however, they can rapidly release Zn2+, causing cytotoxicity. In this study, a potential dental implant modification was creatively developed as ZnO nanoparticle-loaded mesoporous TiO2 coatings (nZnO/MTC-Ti) via the evaporation-induced self-assembly method (EISA) and one-step spin coating. The mesoporous TiO2 coatings (MTCs) regulated the synthesis and loading of ZnO NPs inside the nanosized pores. The synergistic effects of MTC and ZnO NPs on nZnO/MTC-Ti not only controlled the long-term steady-state release of Zn2+ but also optimized the charge distribution on the surface. Therefore, the cytotoxicity of ZnO NPs was resolved without triggering excessive reactive oxygen species (ROS). The increased extracellular Zn2+ further promoted a favorable intracellular zinc ion microenvironment through the modulation of zinc transporters (ZIP1 and ZnT1). Owing to that, the adhesion, proliferation, and osteogenic activity of bone mesenchymal stem cells (BMSCs) were improved. Additionally, nZnO/MTC-Ti inhibited the proliferation of oral pathogens (Pg and Aa) by inducing bacterial ROS production. For in vivo experiments, different implants were implanted into the alveolar fossa of Sprague-Dawley rats immediately after tooth extraction. The nZnO/MTC-Ti implants were found to possess a higher capability for enhancing bone regeneration, antibiosis, and osseointegration in vivo. These findings suggested the outstanding performance of nZnO/MTC-Ti implants in accelerating osseointegration and inhibiting bacterial infection, indicating a huge potential for solving immediate/early loading risks and peri-implantitis of dental implants.

Emergency tracheal intubation peri-operative risk factors and prognostic impact after esophagectomy.

BACKGROUND: Emergent endotracheal intubation (ETI) is a serious complication after Oesophagectomy. It is still unclear that perioperative risk factors and prognosis of these patients with ETI. METHODS: Between January 2015 and December 2018, 21 patients who received ETI after esophagectomy were enrolled (ETI group) at the department of thoracic surgery, Fujian Union hospital, China. Each study subject matched one patient who underwent the same surgery in the current era were included (control group). Patient characteristics and perioperative factors were collected. RESULTS: Patients with ETI were older than those without ETI (p = 0.022). The patients with history of smoking in ETI group were significantly more than those in control group (p = 0.013). The stay-time of postanesthesia care unit (PACU) in ETI group was significantly longer than that in control group (p = 0.001). The incidence of anastomotic leak or electrolyte disorder in ETI group was also higher than that in control group (p = 0.014; p = 0.002). Logistic regression analysis indicated history of smoke (HR 6.43, 95%CI 1.39-29.76, p = 0.017) and longer stay time of PACU (HR 1.04, 95%CI 1.01-1.83, p = 0.020) both were independently associated with higher risks of ETI. The 3-year overall survival (OS) rates were 47.6% in patients with ETI and 85.7% in patients without ETI (HR 4.72, 95%CI 1.31-17.00, p = 0.018). COX regression analysis indicated ETI was an independent risk factor affecting the OS. CONCLUSION: The study indicated that history of smoking and longer stay-time in PACU both were independently associated with higher risks of ETI; and ETI was an independent risk factor affecting the OS of patients after esophagectomy. TRIAL REGISTRATION: This trial was retrospectively registered with the registration number of ChiCTR2000038549.

[Application of CAD in custom tray design for teaching of dental postgraduates].

PURPOSE: To evaluate the teaching effect of making custom trays via CAD in dental postgraduates. METHODS: Twenty-seven dental postgraduates from first to third grade at the School and Hospital of Stomatology, Tongji University, Shanghai were given an informed consent to explain and request participation in the study. First, a lecture about the theory and process of fabricating custom tray via traditional hand-made method and CAD technique was given, then the students fabricated custom trays via the two methods and completed an online survey. The working time, margin extension and students' preference were analyzed with SPSS 22.0 software package. RESULTS: The working time was shorter, the margin extension was superior, and students' preference was higher via CAD than traditional method, the difference was significant(P＜0.05). CONCLUSIONS: CAD is more conducive to enhance students' understanding of custom tray manufacturing process and relevant theoretical knowledge. It is recommended to integrate digital technology into dental curriculum.

Aligned electrospun poly(L-lactide) nanofibers facilitate wound healing by inhibiting macrophage M1 polarization via the JAK-STAT and NF-κB pathways.

Delayed wound healing remains a challenge, and macrophages play an important role in the inflammatory process of wound healing. Morphological changes in macrophages can affect their phenotype, but little is known about the underlying mechanism. Aligned electrospun nanofibers have natural advantages in modulating cell morphology. Therefore, the current study constructed aligned electrospun nanofibers that could transform macrophages into elongated shapes. Our results demonstrated that aligned nanofibers without exogenous cytokines could downregulate the proinflammatory M1 phenotype and upregulate the prohealing M2 phenotype in an inflammatory environment. Importantly, our study revealed that aligned electrospun nanofibers could inhibit macrophage M1 polarization via the JAK-STAT and NF-κB pathways. Furthermore, the conditioned medium from macrophages cultured on aligned nanofibers could encourage fibroblast migration, proliferation and collagen secretion. In vivo, aligned nanofibers alleviated the inflammatory microenvironment, promoted angiogenesis and accelerated wound healing in mouse skin defects by modulating macrophage phenotypes. Collectively, aligned electrospun nanofibers can influence macrophage polarization via the JAK-STAT and NF-κB pathways and attenuate the local inflammatory response in skin wounds. This study provides a potential strategy to modulate macrophage polarization and promote wound healing by controlling the topology of biomaterials and offers a new perspective for the application of nanotechnology in wound healing.

Modified long-axis in-plane ultrasound-guided radial artery cannulation in adult patients: A randomized controlled trial.

INTRODUCTION: For adults with small radial arteries, ultrasound-guided radial artery cannulation remains challenging and the relevant data is currently lacking. The study aimed to test the hypothesis that modified long-axis in-plane ultrasound guidance (M-LAIP) would improve success rates of radial artery cannulation in this population. PATIENTS AND METHODS: This was a prospective, randomised, and controlled clinical study that enrolled 201 adult patients with diameters of the radial artery less than 2.2 mm. Patients were randomised to M-LAIP, short-axis out-of-plane (SAOP), or conventional palpation (C-P) group according to different approaches of radial artery cannulation (M-LAIP, SAOP, and C-P). Outcome measurements included the success rate, cannulation time, and cannulation-related adverse events. RESULTS: The cannulation success rate was significantly higher in the M-LAIP group than in the SAOP or C-P groups (first success rate: 80.3% vs. 53.8% or 33.8%; P < 0.001; total success rate: 93.9% vs. 78.5% or 50.8%; P < 0.001). Total cannulation time in the M-LAIP group was shorter than that in the SAOP group (P = 0.002) or the C-P group (P < 0.001). The rates of posterior wall puncture and haematoma in the M-LAIP group were lower than that in the SAOP group or C-P group (P < 0.008). CONCLUSION: The use of the M-LAIP approach significantly improved the success rate of radial artery cannulation, shortened procedure time, and lowered the rates of posterior wall puncture and haematoma in adults with radial artery diameters less than 2.2 mm, compared with that achieved by the SAOP or C-P approach.

The effects of alignment and diameter of electrospun fibers on the cellular behaviors and osteogenesis of BMSCs.

Electrospun fiber scaffolds, due to their mimicry of bone extracellular matrix (ECM), have become an important biomaterial widely applied in bone tissue engineering in recent years. While topographic cues of electrospun membranes such as alignment and diameter played vital roles in determining cellular behaviors. Yet few researches about the effects of these two significant parameters on osteogenesis have been reported. Thus, the present work explored the influence of aligned and random poly (L-lactic acid) (PLLA) fiber matrices with diameters of nanoscale (0.6 µm) and microscale (1.2 µm), respectively, on cellular responses of bone marrow mesenchymal stem cells (BMSCs), such as cell adhesion, migration, proliferation and osteogenesis. Our results revealed that aligned nanofibers (AN) could affect cell morphology and promote the migration of BMSCs after 24 h of cell culturing. Besides, AN group was observed to possess excellent biocompatibility and have significantly improved cell growth comparing with random nanofibers. More importantly, in vitro osteogenesis researches including ALP and Alizarin Red S staining, qRT-PCR and immunofluorescence staining demonstrated that BMSCs culturing on AN group exhibited higher osteogenic induction proficiency than that on aligned microfibers (AM) and random fiber substrates (RN and RM). Accordingly, aligned nanofiber scaffolds have greater application potential in bone tissue engineering.

Polymorphisms of 5-hydroxytryptamine receptor type 3B gene and clinical characteristics for vomiting after breast surgery in chinese han female population.

WHAT IS KNOWN AND OBJECTIVE: The 5-hydroxytryptamine type 3B receptor (HTR3B) is involved in postoperative vomiting. We aimed to investigate whether genomic variations of rs1176744 and rs1672717 in HTR3B are associated with postoperative vomiting (POV) in the Chinese Han female population after surgery. METHODS: Five hundred and sixty-eight female patients classified as ASA I-II undergoing breast surgery under standard general anaesthesia were enrolled in the study. Episodes of POV in the first 24 h after surgery were recorded. Targeted single nucleotide polymorphisms (SNPs) in the HTR3B gene were identified by genotyping using the SNPscanTM technique. Univariate and multivariate analyses were conducted to investigate the association between SNPs and POV. RESULTS: We eventually analysed 407 subjects undergoing breast surgery under general anaesthesia. Of these, 104(25.6%) patients suffered POV within 24 h after surgery. In the multivariate logistic regression analysis, we found that age≥50 years (p = 0.012) and longer duration of surgery (p = 0.019) were independent risk factors for POV. Simultaneously, in the dominant model of rs1672717, compared with the AA genotype, GG+GA carriers suffered more POV (OR=1.669, p = 0.038). However, the use of atropine reduced the incidence of POV in our study (p = 0.019). WHAT IS NEW AND CONCLUSION: Our investigation demonstrated that polymorphism of rs1672717 (HTR3B) may be a genetic risk factor for developing POV. TRIAL REGISTRATION: clinicaltrials.gov identifier: NCT03705026.

Evaluation of Precision of Custom Edentulous Trays Fabricated with 3D Printing Technologies.

PURPOSE: To evaluate the reserved space quantity and printing accuracy of custom edentulous trays produced by two 3D printing methods (fused deposition modeling [FDM] and stereolithography apparatus [SLA]) and to compare them to traditional handmade (HM) methods. MATERIALS AND METHODS: The tissue surface data of maxillary and mandibular edentulous gypsum models were obtained through a 3D scanner to design the digital custom trays in Geomagic software. The custom trays were then printed with FDM and SLA technologies, and handmade custom trays were used as control. The scanned data of printing trays were registered with their digital data, and the printing errors were analyzed using the deviation analysis function. The distances between the tissue surface of gypsum models and the custom trays were measured in ImageWare and represented by 3D deviation. RESULTS: None of the six groups revealed a significant difference (P > .05) compared to the set value of 1.00 mm. In the SLA group, the deviation of the mandibular area was significantly closer to the set value than for the HM group (P < .05), while no significant difference was displayed between the other groups. For the printing error between the two 3D groups, the SLA method showed significantly less error and better stability (P < .001). CONCLUSION: 3D-printed custom trays can meet clinical needs in the adaptability of tissue surfaces, and SLA-printed trays revealed better precision and less error than the other two methods. Accordingly, the use of SLA technology to make a 3D-printed custom tray is expected to be promoted in clinical practice.

Emergency tracheal intubation during off-hours is not associated with increased mortality in hospitalized patients: a retrospective cohort study.

BACKGROUND: The prognosis of hospitalized patients after emergent endotracheal intubation (ETI) remains poor. Our aim was to evaluate the 30-d hospitalization mortality of subjects undergoing ETI during daytime or off-hours and to analyze the possible risk factors affecting mortality. METHODS: A single-center retrospective study was performed at a university teaching facility from January 2015 to December 2018. All adult inpatients who received ETI in the general ward were included. Information on patient demographics, vital signs, ICU (Intensive care unit) admission, intubation time (daytime or off-hours), the department in which ETI was performed (surgical ward or medical ward), intubation reasons, and 30-d hospitalization mortality after ETI were obtained from a database. RESULTS: Over a four-year period, 558 subjects were analyzed. There were more male than female in both groups (115 [70.1%] vs 275 [69.8%]; P = 0.939). A total of 394 (70.6%) patients received ETI during off-hours. The patients who received ETI during the daytime were older than those who received ETI during off-hours (64.95 ± 17.54 vs 61.55 ± 17.49; P = 0.037). The BMI of patients who received ETI during the daytime was also higher than that of patients who received ETI during off-hours (23.08 ± 3.38 vs 21.97 ± 3.25; P < 0.001). The 30-d mortality after ETI was 66.8% (373), which included 68.0% (268) during off-hours and 64.0% (105) during the daytime (P = 0.361). Multivariate Cox regression analysis found that the significant factors for the risk of death within 30 days included ICU admission (HR 0.312, 0.176-0.554) and the department in which ETI was performed (HR 0.401, 0.247-0.653). CONCLUSIONS: The 30-d hospitalization mortality after ETI was 66.8%, and off-hours presentation was not significantly associated with mortality. ICU admission and ETI performed in the surgical ward were significant factors for decreasing the risk of death within 30 days. TRIAL REGISTRATION: This trial was retrospectively registered with the registration number of ChiCTR2000038549 .

One-step treatment of periodontitis based on a core-shell micelle-in-nanofiber membrane with time-programmed drug release.

As a chronic inflammatory disease, periodontitis is responsible for irreversible soft tissue damage and severe alveolar bone resorption. However, curative effects of current therapies are largely confined by the difficulty to simultaneously achieve anti-inflammation and bone regeneration. Also, the dynamic environment in oral cavity easily causes the drugs swallowed or rinsed away by saliva. We report here a one-step treatment based on a core-shell nanofiber membrane fabricated by coaxial electrospinning. Polymeric micelles containing SP600125 were distributed in the shell, while BMP-2 was incorporated in the core. After crosslinking, the nanofiber membrane displayed a prolonged degradation and release period up to 4 weeks. The release of SP600125 was detected at beginning, whereas BMP-2 was not released until day 12. Such a time-programmed release behavior was proved desirable for suppressing the expression of pro-inflammatory factors and enhancing the osteogenic induction in vitro. Further in vivo investigation confirmed that, by simply covering the periodontitis site with our nanofiber membrane, alveolar destruction was largely avoided and bone defects recovered within 2 month. Taken together, we believe that the use of our membrane with sequential release of SP600125 and BMP-2 may become a convenient and highly comprehensive therapy for periodontitis.

The effects of different doses of teriparatide on bisphosphonate-related osteonecrosis of the jaw in mice.

OBJECTIVES: This study aimed to investigate the therapeutic effect of different doses of teriparatide (TPTD) on bisphosphonate-related osteonecrosis of the jaw (BRONJ). MATERIALS AND METHODS: To establish the BRONJ model, 20 mice were randomly divided into two groups: a group that received tail vein administration of zoledronic acid with dexamethasone (ZA-125 µg/kg, DEX 5 mg/kg) and a group that received saline weekly. The mice subsequently underwent bilateral maxillary first molar extraction. After 8 weeks of modelling administration, the maxilla samples were examined by micro-computed tomography and histological staining (haematoxylin and eosin, Masson's trichrome and tartrate-resistant acid phosphatase) and the cytokine level was measured (enzyme-linked immunosorbent assay and Western blot). To determine the role of TPTD in BRONJ, the same protocol as previously described was applied in 100 mice (80 received ZA + DEX, and 20 received saline). After 8 weeks of modelling administration, 80 ZA + DEX mice were randomly divided into four groups: three groups with subcutaneous administration of TPTD (i.e. T1-3, T2-10 and T3-30 µg kg-1  day-1 ) and one group with saline daily for the next 8 weeks. The other 20 saline mice continued to receive saline daily. RESULTS: In Part 1, the level of receptor activator of nuclear factor-kappa Β ligand and the numbers of osteoclasts differed between the model and control groups. In Part 2, we found that TPTD had a positive effect on BRONJ in a mouse model based on clinical and histomorphological observations. Among the three treatment groups, the T1 and T2 groups significantly differed from the model group, whereas the T3 group showed no statistical differences. CONCLUSION: Subcutaneous administration of TPTD has a beneficial effect on BRONJ in mice. Nevertheless, further studies are needed to determine whether the therapeutic effect on BRONJ is dose-dependent.

Modified long-axis in-plane ultrasound technique versus conventional palpation technique for radial arterial cannulation: A prospective randomized controlled trial.

BACKGROUND: A low first-pass success rate of radial artery cannulation was obtained when using the conventional palpation technique (C-PT) or conventional ultrasound-guided techniques, we; therefore, evaluate the effect of a modified long-axis in-plane ultrasound technique (M-LAINUT) in guiding radial artery cannulation in adults. METHODS: We conducted a prospective, randomized and controlled clinical trial of 288 patients undergoing radial artery cannulation. Patients were randomized 1:1 to M-LAINUT or C-PT group at Fujian Medical University Union Hospital between 2017 and 2018. Radial artery cannulation was performed by 3 anesthesiologists with different experience. The outcome was the first and total radial artery cannulation success rates, the number of attempts and the cannulation time, and incidence of complications. RESULTS: Two hundred eighty-five patients were statistically analyzed. The success rate of first attempt was 91.6% in the M-LAINUT group (n = 143) and 57.7% in the C-PT group (n = 142; P < .001) (odds ratio, 7.9; 95% confidence interval, 4.0-15.7). The total success rate (≤5 minutes and ≤3 attempts) in the M-LAINUT group was 97.9%, compared to 84.5% in the palpation group (P < .001) (odds ratio, 8.5; 95% confidence interval, 2.5-29.2). The total cannulation time was shorter and the number of attempts was fewer in the M-LAINUT group than that in the C-PT group (P < .05). The incidence of hematoma in the C-PT group was 19.7%, which was significantly higher than the 2.8% in the M-LAINUT group (P < .001). CONCLUSIONS: Modified long-axis in-plane ultrasound-guided radial artery cannulation can increase the first and total radial artery cannulation success rates, reduce the number of attempts, and shorten the total cannulation time in adults.

Double-edged effects and mechanisms of Zn2+ microenvironments on osteogenic activity of BMSCs: osteogenic differentiation or apoptosis.

Zinc-incorporated biomaterials show promoting effects on osteogenesis; however, excessive zinc ions lead to cytotoxic reactions and also have other adverse effects. Therefore, the double-edged effects of Zn2+ microenvironments on osteogenesis may become critical issues for new material development. This study systematically investigated the bidirectional influences of diverse Zn2+ microenvironments on the cell adhesion, proliferation, osteogenic differentiation and apoptosis of rBMSCs. Furthermore, the mechanisms of zinc-induced osteogenic differentiation of rBMSCs and of cell apoptosis induced by high concentration of Zn2+ were both discussed in detail. The results indicated that the Zn2+ microenvironments of 2 µg mL-1 and 5 µg mL-1 effectively improved the initial adhesion and proliferation of rBMSCs, while that of 15 µg mL-1 had exactly the opposite effect. More importantly, the suitable Zn2+ microenvironments (2 µg mL-1 and 5 µg mL-1) moderately increased the intracellular Zn2+ concentration by regulating zinc transportation, and then activated the MAPK/ERK signaling pathway to induce the osteogenic differentiation of rBMSCs. In contrast, the high Zn2+ concentration (15 µg mL-1) not only inhibited the osteogenic differentiation of rBMSCs by damaging intracellular zinc homeostasis, but also induced rBMSC apoptosis by enhancing intracellular ROS generation. The current study clarified the double-edged effects of Zn2+ microenvironments on the osteogenic properties of rBMSCs and the related mechanisms, and may provide valuable guidance for optimizing the design of zinc-doped biomaterials and zinc-based alloys.

Nobiletin-loaded micelles reduce ovariectomy-induced bone loss by suppressing osteoclastogenesis.

BACKGROUND: Nobiletin (NOB), a polymethoxy flavonoid, possesses anti-cancer and anti-inflammatory activities, has been reported that it played role in anti-osteoporosis treatment. However, previous research did not focus on practical use due to lack of hydrophilicity and cytotoxicity at high concentrations. The aim of this study was to develop a therapeutic formulation for osteoporosis based on the utilization of NOB. METHODS: In this study, NOB-loaded poly(ethylene glycol)-block-poly(e-caprolactone) (NOB-PEG-PCL) was prepared by dialysis method. The effects on osteoclasts and anti-osteoporosis functions were investigated in a RANKL-induced cell model and ovariectomized (OVX) mice. RESULTS: Dynamic light scattering and transmission electron microscopy examination results revealed that the NOB-PEG-PCL had a round shape, with a mean diameter around 124 nm. The encapsulation efficiency and drug loading were 76.34±3.25% and 7.60±0.48%, respectively. The in vitro release of NOB from NOB-PEG-PCL showed a remarkably sustained releasing characteristic and could be retained at least 48 hrs in pH 7.4 PBS. Anti-osteoclasts effects demonstrated that the NOB-PEG-PCL significantly inhibited the formation of tartrate-resistant acid phosphatase (TRAP)-positive multinuclear cells stimulated by RANKL. Furthermore, the NOB-PEG-PCL did not produce cytotoxicity on bone marrow-derived macrophages (BMMs). The mRNA expressions of genetic markers of osteoclasts including TRAP and cathepsin K were significantly decreased in the presence of NOB-PEG-PCL. In addition, the NOB-PEG-PCL inhibited OC differentiation of BMMs through RANKL-induced MAPK signal pathway. After administration of the NOB-PEG-PCL, NOB-PEG-PCL prevented bone loss and improved bone density in OVX mice. These findings suggest that NOB-PEG-PCL might have great potential in the treatment of osteoporosis. CONCLUSION: The results suggested that NOB-PEG-PCL micelles could effectively prevent NOB fast release from micelles and extend circulation time. The NOB-PEG-PCL delivery system may be a promising way to prevent and treat osteoporosis.

Enhanced efficacy of baicalin-loaded TPGS polymeric micelles against periodontitis.

As a chronic infectious disease, periodontitis is the main cause of teeth exfoliation due to its severe inflammatory reaction and periodontal tissue destruction. Recent reports have shown that baicalin could inhibit the NF-κB signaling pathway in inflammatory activity of periodontitis, but the efficacy of baicalin is limited due to its poor water solubility. In this work, we report the fabrication and application of baicalin encapsulated D-α-tocopherol polyethylene glycol 1000 succinate (TPGS) polymeric micelles (PMs) through thin-film hydration method. The monodispersed micelles showed a spherical shape in aqueous solution and a prolonged drug-release kinetic. After baicalin was loaded into PMs, cytotoxicity and apoptosis induction were both decreased. The expression of genes (including TNF-α, IL-1ß, RANKL and NF-κB) and the phosphorylation level of NF-κB p65 protein in lipopolysaccharide (LPS)-induced rat gingival fibroblasts were also reduced. Further investigation of drug efficacy in a rat periodontal disease model confirmed that the use of baicalin-PMs could reduce the destruction of alveolar bone and gingival fiber. Moreover, the therapeutic effect of baicalin-PMs was significantly better than that of free baicalin. These results suggest that the direct injection of micelles containing water-insoluble drugs may become a simple but effective method for treating periodontitis.

Dual micelles-loaded gelatin nanofibers and their application in lipopolysaccharide-induced periodontal disease.

INTRODUCTION: Combined therapies utilizing inhibitors to remove pathogens are needed to suppress lipopolysaccharide (LPS)-induced periodontal disease. We prepared a novel, multi-agent delivery scaffold for periodontal treatment. METHODS: In this study, we synthesized SP600125 (a JNK inhibitor) and SB203580 (a p38 inhibitor) drug-loaded poly(ethylene glycol)-block-caprolactone copolymer via dialysis method. The physical property of micelles was characterized through dynamic light scattering and transmission electron microscopy. The cell growth and LPS-induced MMP-2 and MMP-13 expression were evaluated through CCK-8, real-time PCR and Western blot assay. The release of SP600125 and SB203580 from different scaffolds was estimated. Microcomputed tomography and histology were used for evaluating the effect of the micelles-loaded nanofibers on the treatment of class II furcation defects in dogs. RESULTS: The drug was then successfully incorporated into gelatin fibers during electrospinning process. We confirmed that the micelles had spherical structure and an average particle size of 160 nm for SP600125-micelles (SP-Ms) and 150 nm for SB203580-micelles (SB-Ms). The nanofiber scaffold showed excellent encapsulation capability, in vitro drug-release behavior, and cell compatibility. Real-time PCR and Western blot assay further indicated that LPS-induced MMP-2 and MMP-13 expression was significantly inhibited by the scaffold. CONCLUSION: The results suggested that the dual drug-loaded system developed in this study might become a highly effective therapy for periodontal disease.

Microfiber-Reinforced Composite Hydrogels Loaded with Rat Adipose-Derived Stem Cells and BMP-2 for the Treatment of Medication-Related Osteonecrosis of the Jaw in a Rat Model.

Severe adverse reactions of bisphosphonates and anti-resorptive or anti-angiogenic medications, termed medication-related osteonecrosis of the jaw (MRONJ), have been reported. MRONJ are difficult to completely cure and could cause great pain to patients. Recent studies have shown that mesenchymal stem cell (MSC) therapies are effective for treating MRONJ, but the method of intravenous injection is unstable and increases the risk of producing tumors. In the present study, low-acyl gellan gum (LAGG) hydrogels were modified with hemicellulose polysaccharide microfibers (PMs) to improve the performance of supporting three-dimensional (3D) cell growth. LAGG-PM composite hydrogels were found to be nontoxic to rat adipose-derived stem cells (rADSCs) in vitro. The hydrogels also promoted the secretion of angiogenic factors, induced osteoclastogenesis by conditioned medium, and supported osteogenic marker expression after the addition of human bone morphogenetic protein-2 (BMP-2). Due to its injectability, the LAGG-PM composite hydrogel incorporated with rADSCs and BMP-2 could be applied into the MRONJ lesion site, which promoted mucosal recovery, bone tissue reconstruction, and osteoclastogenesis. This study confirms the potential applications of LAGG-PM composite hydrogels as 3D cell culture platforms and delivery vehicles for the treatment of MRONJ in a rat model.