Cell Compatibility of the Micro-Arc Oxidized Surface of Large Plastic Deformed TA2 In Vitro

2016 ◽  
Vol 852 ◽  
pp. 1220-1226
Author(s):  
Li Hua Zhu ◽  
Xiao Jing Xu ◽  
Ting Zhuo Chen ◽  
Xiao Ya Niu ◽  
Lin Xu

The cell toxicity, cell proliferation and cell adhesion behaviors on the micro-arc oxidized surface of the conventional and large plastic deformed pure titanium (TA2) were studied. The results show that all samples have no cell toxicity. The cell proliferation ability on the surface of the large plastic deformed pure titanium (TA2) is better than that of the conventional pure titanium (TA2). The numbers of cells adhered on micro-arc oxidized surface of the large plastic deformed of pure titanium (TA2) are more than that of conventional pure titanium (TA2). And the distribution of the cells and cell morphologies are better than that of the conventional pure titanium (TA2). Results all above show that structure refinement of large deformation of pure titanium (TA2) has more significant improvement on the cell compatibility of the micro-arc oxidized modified films.

2021 ◽  
Author(s):  
Rosemarie E. Gough ◽  
Matthew C. Jones ◽  
Thomas Zacharchenko ◽  
Shimin Le ◽  
Miao Yu ◽  
...  

AbstractTalin is a mechanosensitive component of adhesion complexes that directly couples integrins to the actin cytoskeleton. In response to force, talin undergoes switch-like behaviour of its multiple rod domains that modulate interactions with its binding partners. Cyclin-dependent kinase-1 (CDK1) is a key regulator of the cell cycle, exerting its effects through synchronised phosphorylation of a large number of protein targets. CDK1 activity also maintains adhesion during interphase, and its inhibition is a prerequisite for the tightly choreographed changes in cell shape and adhesiveness that are required for successful completion of mitosis. Using a combination of biochemical, structural and cell biological approaches, we demonstrate a direct interaction between talin and CDK1 that occurs at sites of integrin-mediated adhesion. Mutagenesis demonstrated that CDK1 contains a functional talin-binding LD motif, and the binding site within talin was pinpointed to helical bundle R8 through the use of recombinant fragments. Talin also contains a consensus CDK1 phosphorylation motif centred on S1589; a site that was phosphorylated by CDK1in vitro. A phosphomimetic mutant of this site within talin lowered the binding affinity of KANK and weakened the mechanical response of the region, potentially altering downstream mechanotransduction pathways. The direct binding of the master cell cycle regulator, CDK1, to the primary integrin effector, talin, therefore provides a primordial solution for coupling the cell proliferation and cell adhesion machineries, and thereby enables microenvironmental control of cell division in multicellular organisms.SummaryThe direct binding of the master cell cycle regulator, CDK1, to the primary integrin effector, talin, provides a primordial solution for coupling the cell proliferation and cell adhesion machineries, and thereby enables microenvironmental control of cell division.


2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Akiko Obata ◽  
Eri Miura-Fujiwara ◽  
Akimitsu Shimizu ◽  
Hirotaka Maeda ◽  
Masaaki Nakai ◽  
...  

Ti-29Nb-13Ta-4.6Zr (TNTZ) alloy has excellent mechanical properties and bone conductivity. For dental application, TNTZ surfaces were converted to white oxidized layer by a simple heat treatment in air to achieve the formation of aesthetic surfaces. The oxidized layer formed by the heat treatment at 1000°C for 0.5 or 1 hr was whiter and joined to TNTZ substrate more strongly than that formed by the treatment at 900°C. The layer consisted of TiO2(rutile), TiNb2O7, and TiTa2O7and possessed ~30 μm in thickness for the sample heat-treated at 1000°C and ~10 μm for that heat-treated at 900°C. The surface average roughness and the wettability increased after the heat treatment. The spreading and proliferation level of mouse osteoblast-like cell (MC3T3-E1 cell) on the heat-treated sample were almost the same as those on as-prepared one. The cell spreading on TNTZ was better than those on pure titanium (CP Ti) regardless of the heat treatment for the samples. There was no deterioration in thein vitrocell compatibility of TNTZ after the oxidized layer coating by the heat treatment.


2010 ◽  
Vol 299 (3) ◽  
pp. L393-L400 ◽  
Author(s):  
William Y. C. Chang ◽  
Debbie Clements ◽  
Simon R. Johnson

Matrix metalloproteinases (MMPs) have been implicated in lung cyst formation in lymphangioleiomyomatosis (LAM). As doxycycline inhibits MMP activity in vivo, some patients take doxycycline, as one report has suggested a possible benefit in LAM. However, there have been no randomized controlled clinical trials of doxycycline for LAM, and any mechanism of action is unclear. Here, we examine previously proposed mechanisms of actions. Cell proliferation and adhesion were examined using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) reduction and Cytomatrix cell adhesion kits. Apoptosis was examined by TdT-mediated dUTP nick end labeling (TUNEL) assay. MMP-2 expression was examined by quantitative real-time PCR and zymography in doxycycline-treated ELT3 cells and tumor growth using angiomyolipoma-derived tumor xenografts in nude mice. In ELT3 cells, ≥25 μg/ml doxycycline decreased proliferation, increased apoptosis, and caused a change in cell morphology associated with redistribution of actin stress filaments. Reduction in proliferation was also seen in human angiomyolipoma-derived cells. Cell adhesion to ECM proteins was decreased by doxycycline at 50 μg/ml and prevented detachment of already adherent cells. There was no effect of doxycycline on MMP-2 expression or activity in vitro. In the xenograft model, doxycycline (30 mg·kg−1·day−1) had no effect on tumor growth, final tumor weight, or tumor lysate MMP levels. Doxycycline at doses ≥ 25 μg/ml inhibited cell proliferation and adhesion, possibly by a toxic effect. Doxycycline had no effect on MMP-2 expression or activity or tumor growth in the xenograft model. Any possible in vivo effect is unlikely to be mediated by MMP-2 or reduced cell proliferation.


Reproduction ◽  
2000 ◽  
pp. 275-281 ◽  
Author(s):  
KM Kirkup ◽  
AM Mallin ◽  
CA Bagnell

Epithelial cadherin (E-cadherin) is a member of the cadherin family of calcium-dependent cell adhesion molecules and is present in the ovary. Although expression of E-cadherin is high in healthy pig granulosa cells and low in granulosa cells of atretic follicles, the importance of E-cadherin-mediated adhesion in granulosa cell function is unclear. The aim of the present study was to determine the impact of immunoneutralization of E-cadherin on granulosa cell adhesion, DNA synthesis and cell proliferation in vitro. Before attachment, pig granulosa cells were exposed to a monoclonal E-cadherin antibody (DECMA-1) which blocks E-cadherin function. Controls included substitution of the antibody with either mouse ascites fluid or another E-cadherin antibody directed against the cytoplasmic domain and which was therefore inaccessible in intact cells. Both granulosa cell proliferation and insulin-like growth factor I-induced DNA synthesis were inhibited significantly in the presence of DECMA-1 compared with controls (P < 0.05). Control granulosa cells in culture formed large clusters with many cells packed tightly together. However, after 48 h exposure to the function-perturbing E-cadherin antibody, there was a significant decrease in the size of the granulosa cell clusters (P < 0.05) and the degree of cell-cell contact was reduced compared with control cultures. No effects on DNA synthesis, cell proliferation or cell adhesion were observed when DECMA-1 was substituted with either mouse ascites fluid or the antibody specific for the cytoplasmic domain of E-cadherin. In conclusion, these data provide evidence to support the hypothesis that E-cadherin is important for maintaining granulosa cell contact, DNA synthesis and cell proliferation in vitro. These results indicate that E-cadherin plays a fundamental role in maintaining both the structure and function of ovarian follicles.


2009 ◽  
Vol 24 (1_suppl) ◽  
pp. 169-182 ◽  
Author(s):  
Wang Tianshi ◽  
Zhang Renji ◽  
Yan Yongnian

In this study, a hydroxyapatite (HA) was coated on a pure titanium surface by means of a complex oxidation and hydrothermal treatment. First an anodic oxidation was done on the titanium plates, followed by micro-arc oxidation. The HA-coated specimens and pure titanium specimens were immersed in SLB for 1, 5, and 10 days, respectively, to study their electrochemical behavior. The corrosion currents of HA-coated specimens were less than pure titanium specimens. This indicated that HA coating prevented surface metal ions of the implant from dissolving, thereby, reducing the tissue toxicity. The cytotoxic effect on fibroblasts L929 cells was measured by cell counting after being seeded for 2, 4, 8, 12, and 24 h. The number of surface cell attachments on the HA-coated specimens was much greater than on pure titanium specimens. The morphology of the cells on the HA coating had normal shapes and spread well with some cells climbing onto surface pores while cells on the pure titanium were oval shaped. The results confirm that the cell compatibility on HA-coated ion titanium surfaces is much better than pure titanium.


2019 ◽  
Vol 2019 ◽  
pp. 1-8 ◽  
Author(s):  
Xiongfeng Tang ◽  
Yanguo Qin ◽  
Xinyu Xu ◽  
Deming Guo ◽  
Wenli Ye ◽  
...  

For bone tissue engineering, the porous scaffold should provide a biocompatible environment for cell adhesion, proliferation, and differentiation and match the mechanical properties of native bone tissue. In this work, we fabricated porous polyetherimide (PEI) scaffolds using a three-dimensional (3D) printing system, and the pore size was set as 800 μm. The morphology of 3D PEI scaffolds was characterized by the scanning electron microscope. To investigate the mechanical properties of the 3D PEI scaffold, the compressive mechanical test was performed via an electronic universal testing system. For the in vitro cell experiment, bone marrow stromal cells (BMSCs) were cultured on the surface of the 3D PEI scaffold and PEI slice, and cytotoxicity, cell adhesion, and cell proliferation were detected to verify their biocompatibility. Besides, the alkaline phosphatase staining and Alizarin Red staining were performed on the BMSCs of different samples to evaluate the osteogenic differentiation. Through these studies, we found that the 3D PEI scaffold showed an interconnected porous structure, which was consistent with the design. The elastic modulus of the 3D PEI scaffold (941.33 ± 65.26 MPa) falls in the range of modulus for the native cancellous bone. Moreover, the cell proliferation and morphology on the 3D PEI scaffold were better than those on the PEI slice, which revealed that the porous scaffold has good biocompatibility and that no toxic substances were produced during the progress of high-temperature 3D printing. The osteogenic differentiation level of the 3D PEI scaffold and PEI slice was equal and ordinary. All of these results suggest the 3D printed PEI scaffold would be a potential strategy for bone tissue engineering.


2006 ◽  
Vol 18 (04) ◽  
pp. 185-189 ◽  
Author(s):  
I-CHI LEE ◽  
TAI-HORNG YOUNG

Poly (lactic acid) is a biodegradable biomedical material that has been used for connective tissue reconstruction. In this work, poly-L-lactide (PLLA) membranes with different morphologies were prepared by phase separation method. Otherwise, biomaterials coated with various extracellular matrix (ECM) have been shown to promote cell adhesion, proliferation, and differentiation. In addition, the in vitro interaction of medial collateral ligament cells (MCLs) and PLLA membranes with dense, porous and particulate morphologies and with ECM coating was investigated. It was found that the cell compatibility of three types of PLLA membranes almost the same before coating ECM. The results also revealed that collagen type I could improve ligament cells adhesion and fibronectin could improve ligament cells growth, and this effect was most obvious in particulate membrane. Therefore, because the PLLA materials with particulate structure could adsorb more ECM which in turn influenced the cell adhesion and cell growth. The PLLA membrane with the particulate morphology satisfies the biomaterial requirement necessary for temporary scaffold to transplanted ligament cells and provides a means for the architectural design of more complex tissue-engineered systems.


2019 ◽  
Author(s):  
Kaarjel K. Narayanasamy ◽  
Joshua C. Price ◽  
Marwan Merkhan ◽  
Ajile Elttayef ◽  
Jon Dobson ◽  
...  

ABSTRACTThe biocompatibility of surface coated/functionalised magnetic nanoparticles (MNPs) is key to their successful incorporation and application in biological systems. Polyethylene imine (PEI) -coated MNPs provide improved in vitro transfection efficiency compared to conventional chemical methods such as Lipofectamine and cationic polymers, and are also safer than viral transduction. Commercial cell toxicity assays are useful for end-point and high-throughput screening, providing fast results and an overview of cell health. However these assays only take into account cells that have undergone an extreme toxic response leading to cell death. Cell toxicity is a complex process which can be expressed in many forms, through morphological, metabolic, and epigenetic changes. A common indicator of cell stress and toxic response is increased cell adhesion and stress fibre formation. It is important to identify these changes in cells as it may affect downstream results and applications in biomedicine. This study explores the effect of the nanomagnetic transfection agent PEI-coated MNPs (MNP-PEIs) and an external magnetic field on cell behaviour, by studying particle internalization, changes in cellular morphology, and cell adhesion. We found that MNP-PEIs induced cell stress through a dose-dependent increase in cell adhesion via the overexpression of vinculin and formation of actin stress fibres. While the presence of PEI was the main contributor to increased cell stress, free PEI polyplexes induced higher toxicity compared to PEI bound to MNPs. MNPs without PEI coating however did not adversely affect cells suggesting a chemical effect instead of a mechanical one. In addition, genes identified as being associated with actin fibre regulation and cell adhesion, showed significant increases in expression due to the internalization of the MNP-PEI complex. From these results, we identify anomalous cell behaviour, morphology, and gene expression after interaction with MNP-PEIs, as well as a safe dosage to reduce acute cell toxicity.


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