Biocompatibility of Poly-ε-caprolactone-hydroxyapatite composite on mouse bone marrow-derived osteoblasts and endothelial cells

Open Access. Click on the DOI link to access this article at the publisher's website, or download /view it on SOAR.Background. Tissue-engineered bone may be developed by seeding the cells capable of both osteogenesis and vascularization on biocompatible composite scaffolds. The current study investigated the performance of mice bone marrow-derived osteogenic cells and endothelial cells as seeded on hydroxyapatite (HA) and poly-ε-caprolactone (PCL) composite scaffolds. Methods Mononuclear cells were induced to osteoblasts and endothelial cells respectively, which were defined by the expression of osteocalcin, alkaline phosphatase (ALP), and deposits of calcium-containing crystal for osteoblasts, or by the expression of vascular endothelial growth factor receptor-2 (VEGFR-2) and von Willebrand factor (vWF), and the formation of a capillary network in Matrigel™ for endothelial cells. Both types of cell were seeded respectively on PCL-HA scaffolds at HA to PCL weight ratio of 1:1, 1:4, or 0:1 and were evaluated using scanning electron microscopy, ALP activity (of osteoblasts) and nitric oxide production (of endothelial cells) plus the assessment of cell viability. Results The results indicated that HA led to a positive stimulation of osteoblasts viability and ALP activity, while HA showed less influence on endothelial cells viability. An elevated nitric oxide production of endothelial cells was observed in HA-containing group. Conclusion Supplement of HA into PCL improved biocompatible for bone marrow-derived osteoblasts and endothelial cells. The PCL-HA composite integrating with two types of cells may provide a useful system for tissue-engineered bone grafts with vascularization.Peer reviewe

High VEGF with Rapid Growth and Early Metastasis in a Mouse Osteosarcoma Model

A murine model of osteosarcoma was developed to investigate the association between the expression of VEGF and the progression of osteosarcoma. Two human osteosarcoma cell lines with distinct VEGF expressions were introduced into proximal tibiae of immuno-deficient SCID mice, either by direct injection through the cortical bone or surgical exposing and drilling on the tibial metaphysis to seed tumor cells. Bone tumors were obvious on microCT within 4 weeks following osteosarcoma cell inoculation through surgical delivery. In contrast, direct injection without drilling often resulted in periosteal tumors. Although neoplasms were developed regardless of VEGF levels, orthotopic tumors derived from high VEGF-expressing cells were detected 2 weeks earlier on CT images than the ones from VEGF negative cells. At sacrifice, high VEGF tumors were distinctively larger in size and more frequently invaded the adjacent bone tissue. Multiple metastatic lesions were found in all the lung tissues at 8 weeks from high VEGF group, whereas only 1 of 7 VEGF negative tumors exhibited pulmonary metastasis. Overall, this model developed with the surgical tumor cell delivery results in histological and radiographic features more consistent with primary osteosarcoma. Interestingly, VEGF expression correlates with the early establishment, rapid tumor growth, and the development of pulmonary metastasis

Reflection,Transmission, and Absorption of Vortex Beams Propagation in an Inhomogeneous Magnetized Plasma Slab

Based on the angular spectrum expansion and the 4x4 transfer matrix method, an investigation into the reflection, transmission, and absorption of vortex beams in an inhomogeneous magnetized plasma slab is presented. The reflected and transmitted electric fields are expressed by the inverse Fourier transform of the product of the reflected and transmitted coefficients and the angular spectrum amplitude of the incident beam. The intensity profiles, as well as the distortion of OAM states in both the reflected and transmitted beams are simulated and discussed. Through this investigation it could be concluded that both the incident angle and the plasma parameters have significant impact on the magnitudes of reflected and transmitted intensities, and the distortion of OAM states. The effects of the magnetic field and the incident angle on the reflectance, transmittance, and absorptance of the power have also been reported

Assessing Reproducibility of Inherited Variants Detected With Short-Read Whole Genome Sequencing

Background: Reproducible detection of inherited variants with whole genome sequencing (WGS) is vital for the implementation of precision medicine and is a complicated process in which each step affects variant call quality. Systematically assessing reproducibility of inherited variants with WGS and impact of each step in the process is needed for understanding and improving quality of inherited variants from WGS. Results: To dissect the impact of factors involved in detection of inherited variants with WGS, we sequence triplicates of eight DNA samples representing two populations on three short-read sequencing platforms using three library kits in six labs and call variants with 56 combinations of aligners and callers. We find that bioinformatics pipelines (callers and aligners) have a larger impact on variant reproducibility than WGS platform or library preparation. Single-nucleotide variants (SNVs), particularly outside difficult-to-map regions, are more reproducible than small insertions and deletions (indels), which are least reproducible when \u3e 5 bp. Increasing sequencing coverage improves indel reproducibility but has limited impact on SNVs above 30×. Conclusions: Our findings highlight sources of variability in variant detection and the need for improvement of bioinformatics pipelines in the era of precision medicine with WGS

Assessing reproducibility of inherited variants detected with short-read whole genome sequencing

Background: Reproducible detection of inherited variants with whole genome sequencing (WGS) is vital for the implementation of precision medicine and is a complicated process in which each step affects variant call quality. Systematically assessing reproducibility of inherited variants with WGS and impact of each step in the process is needed for understanding and improving quality of inherited variants from WGS. Results: To dissect the impact of factors involved in detection of inherited variants with WGS, we sequence triplicates of eight DNA samples representing two populations on three short-read sequencing platforms using three library kits in six labs and call variants with 56 combinations of aligners and callers. We find that bioinformatics pipelines (callers and aligners) have a larger impact on variant reproducibility than WGS platform or library preparation. Single-nucleotide variants (SNVs), particularly outside difficult-to-map regions, are more reproducible than small insertions and deletions (indels), which are least reproducible when > 5 bp. Increasing sequencing coverage improves indel reproducibility but has limited impact on SNVs above 30x. Conclusions: Our findings highlight sources of variability in variant detection and the need for improvement of bioinformatics pipelines in the era of precision medicine with WGS.Peer reviewe

Control Methods Using Cross-Coupling Effects for Suppression of Rotor/Stator Rubbing System

This paper investigated the influence of cross-coupling effects on the rubbing-related dynamics of rotor/stator systems, The stability analysis on the synchronous full annular rub solution of a rotor/stator system, which includes both the dynamics of the stator and the deformation on the contact surface as well as the cross-coupling terms in velocities and displacements, is carried out. It is found that some cross-coupling effects will benefit the synchronous full annular rubs and some will not. Based on the finding, a control method by generating cross-coupling damping on the stator through the active auxiliary bearing is then proposed in order to suppress the contact severity and avoid the rubbing instability. Numerical simulation shows the validity of the mehtod

Combined Effect of Tides and Wind on Water Exchange in a Semi-Enclosed Shallow Sea

The Bohai Sea is a semi-enclosed shallow sea in China, where the tides and wind are the dominant factors contributing to the water exchange with the Yellow Sea. However, existing studies on this water exchange primarily consider only the effect of tidal action, neglecting the contribution of wind. In this study, numerical models were used to simulate the hydrodynamic processes and tracer transport, with the consideration of both tides and wind. Based on the models, the two time scales, age and half-life, are applied to study the water exchange in the Bohai Sea quantitatively. The results show that the age and half-life decrease significantly when wind is included in the simulation, revealing that wind is an important contributor to the water exchange in such a semi-enclosed shallow sea. Under the combined forcing of tides and wind, the water transport in the Bohai Sea becomes clockwise, in contrast with the counterclockwise transport driven by the tides only. The seasonal-varying wind leads to a fluctuation of water exchange in an annual cycle, with the stronger water exchange in the northern (Liaodong Bay) and the western (Bohai Bay) regions of the Bohai Sea in winter and in the southern part (Laizhou Bay) in summer

Fucoidan from Laminaria japonica Inhibits Expression of GLUT9 and URAT1 via PI3K/Akt, JNK and NF-κB Pathways in Uric Acid-Exposed HK-2 Cells

This work aimed to investigate the effect of fucoidan (FPS) on urate transporters induced by uric acid (UA). The results showed that UA stimulated the expression of glucose transporter 9 (GLUT9) and urate transporter 1 (URAT1) in HK-2 cells, and FPS could reverse the effect. Moreover, UA could activate NF-κB, JNK and PI3K/Akt pathways, but both pathway inhibitors and FPS inhibited the UA-induced activation of these three pathways. These data suggested that FPS effectively inhibited the expression induction of reabsorption transporters URAT1 and GLUT9 by UA, through repressing the activation of NF-κB, JNK and PI3K/Akt signal pathways in HK-2 cells. The in vitro research findings support the in vivo results that FPS reduces serum uric acid content in hyperuricemia mice and rats through inhibiting the expression of URAT1 and GLUT9 in renal tubular epithelial cells. This study provides a theoretical basis for the application of FPS in the treatment of hyperuricemia