scholarly journals Fabricating in vitro nanomaterial scaffolds through IC-compatible microfabrication to modulate mammalian cellular behaviors

2016 ◽  
pp. 93-122
Author(s):  
Chun-Yen Sung ◽  
J. Andrew Yeh ◽  
Chao-Min Cheng
Keyword(s):  
Cellular Behaviors

scholarly journals Living myofibroblast–silicon composites for probing electrical coupling in cardiac systems

2019 ◽  
Vol 116 (45) ◽  
pp. 22531-22539 ◽  
Author(s):  
Menahem Y. Rotenberg ◽  
Naomi Yamamoto ◽  
Erik N. Schaumann ◽  
Laura Matino ◽  
Francesca Santoro ◽  
...  
Keyword(s):  
Silicon Nanowires ◽  
Electrical Coupling ◽  
Cellular Behavior ◽  
Synthetic Materials ◽  
Cellular Behaviors ◽  
Biosignal Processing ◽  
A Cell ◽  
Hybrid Configuration

Traditional bioelectronics, primarily comprised of nonliving synthetic materials, lack cellular behaviors such as adaptability and motility. This shortcoming results in mechanically invasive devices and nonnatural signal transduction across cells and tissues. Moreover, resolving heterocellular electrical communication in vivo is extremely limited due to the invasiveness of traditional interconnected electrical probes. In this paper, we present a cell–silicon hybrid that integrates native cellular behavior (e.g., gap junction formation and biosignal processing) with nongenetically enabled photosensitivity. This hybrid configuration allows interconnect-free cellular modulation with subcellular spatial resolution for bioelectric studies. Specifically, we hybridize cardiac myofibroblasts with silicon nanowires and use these engineered hybrids to synchronize the electrical activity of cardiomyocytes, studying heterocellular bioelectric coupling in vitro. Thereafter, we inject the engineered myofibroblasts into heart tissues and show their ability to seamlessly integrate into contractile tissues in vivo. Finally, we apply local photostimulation with high cell specificity to tackle a long-standing debate regarding the existence of myofibroblast–cardiomyocyte electrical coupling in vivo.

scholarly journals Global H-NS counter-silencing by LuxR activates quorum sensing gene expression

2019 ◽  
Author(s):  
Ryan R Chaparian ◽  
Minh L N Tran ◽  
Laura C Miller Conrad ◽  
Douglas B Rusch ◽  
Julia C van Kessel
Keyword(s):  
Gene Expression ◽  
Quorum Sensing ◽  
Cell Communication ◽  
Binding Activity ◽  
Primary Role ◽  
Dna Binding Activity ◽  
Cellular Behaviors ◽  
A Cell ◽  
Promoter Dna

Abstract Bacteria coordinate cellular behaviors using a cell–cell communication system termed quorum sensing. In Vibrio harveyi, the master quorum sensing transcription factor LuxR directly regulates >100 genes in response to changes in population density. Here, we show that LuxR derepresses quorum sensing loci by competing with H-NS, a global transcriptional repressor that oligomerizes on DNA to form filaments and bridges. We first identified H-NS as a repressor of bioluminescence gene expression, for which LuxR is a required activator. In an hns deletion strain, LuxR is no longer necessary for transcription activation of the bioluminescence genes, suggesting that the primary role of LuxR is to displace H-NS to derepress gene expression. Using RNA-seq and ChIP-seq, we determined that H-NS and LuxR co-regulate and co-occupy 28 promoters driving expression of 63 genes across the genome. ChIP-PCR assays show that as autoinducer concentration increases, LuxR protein accumulates at co-occupied promoters while H-NS protein disperses. LuxR is sufficient to evict H-NS from promoter DNA in vitro, which is dependent on LuxR DNA binding activity. From these findings, we propose a model in which LuxR serves as a counter-silencer at H-NS-repressed quorum sensing loci by disrupting H-NS nucleoprotein complexes that block transcription.

Evaluation of the Effects of Ag Ion Concentration on Osteoblast Activity

2014 ◽  
Vol 631 ◽  
pp. 390-394 ◽  
Author(s):  
S.B. Cho ◽  
G.J. Yoon ◽  
E.M. An ◽  
Y.J. Kim ◽  
T.N. Kim ◽  
...  
Keyword(s):  
Simulated Body Fluid ◽  
Cell Viability ◽  
Body Fluid ◽  
Neutral Red ◽  
Ion Concentration ◽  
Cell Counting ◽  
Osteoblast Activity ◽  
Cellular Behaviors ◽  
Covering Method

We reported the apatite-forming ability of 30CaO∙70SiO2 scaffolds with 0~100 ppm Ag ions by soaking in simulated body fluid (SBF). This study was to evaluate the effects of the concentrations of Ag ions in the 30CaO∙70SiO2 gels on in-vitro biocompatibility of osteoblasts (MC3T3). After seeding cells on the surface of Ag-30CaO∙70SiO2 gels scaffold, cellular behaviors were evaluated by an assay of cell counting kit-8. Cytotoxicity of the scaffold samples was evaluated by employing the extract solutions of the scaffold samples by the assays of neutral red, MTT and BrdU. In addition, live & dead assay was performed by using a gel covering method, which the scaffolds have been directly contacted with the incubated cells on the well plate. According to the results of CCK-8 assay, the optical density value of the absorbance of the resulting solution decreased as the concentration of Ag ions in the scaffolds increased. Moreover, their cell viability was measured to be less than 50% at the Ag concentrations of 50 ppm or more, and dead cells were observed in the experiment results of both the cytotoxicity and gel covering tests. From these experimental results, we concluded that the Ag-30CaO∙70SiO2 scaffolds with less than 50 ppm Ag ion concentration were considered as biocompatible.

scholarly journals Hierarchically electrospraying a PLGA@chitosan sphere-in-sphere composite microsphere for multi-drug-controlled release

2020 ◽  
Vol 7 (4) ◽  
pp. 381-390
Author(s):  
Zhu Liu ◽  
Weilong Ye ◽  
Jingchuan Zheng ◽  
Qindong Wang ◽  
Guowu Ma ◽  
...  
Keyword(s):  
Controlled Release ◽  
Drug Loading ◽  
Uv Spectrophotometry ◽  
Composite Microsphere ◽  
Ionization Time ◽  
Composite Microspheres ◽  
Flight Mass Spectrometry ◽  
Sequential Administration ◽  
Cellular Behaviors

Abstract Sequential administration and controlled release of different drugs are of vital importance for regulating cellular behaviors and tissue regeneration, which usually demands appropriate carriers like microspheres (MS) to control drugs releases. Electrospray has been proven an effective technique to prepare MS with uniform particle size and high drug-loading rate. In this study, we applied electrospray to simply and hierarchically fabricate sphere-in-sphere composite microspheres, with smaller poly(lactic-co-glycolic acid) MS (∼8–10 μm in diameter) embedded in a larger chitosan MS (∼250–300 μm in diameter). The scanning electron microscopy images revealed highly uniform MS that can be accurately controlled by adjusting the nozzle diameter or voltage. Two kinds of model drugs, bovine serum albumin and chlorhexidine acetate, were encapsulated in the microspheres. The fluorescence-labeled rhodamine-fluoresceine isothiocyanate (Rho-FITC) and ultraviolet (UV) spectrophotometry results suggested that loaded drugs got excellent distribution in microspheres, as well as sustained, slow release in vitro. In addition, far-UV circular dichroism and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) results indicated original secondary structure and molecular weight of drugs after electrospraying. Generally speaking, our research proposed a modified hierarchically electrospraying technique to prepare sphere-in-sphere composite MS with two different drugs loaded, which could be applied in sequential, multi-modality therapy.

scholarly journals A Study of Osteocalcin Production In Vitro on Various Hydroxyapatite Based Biomaterials

2007 ◽  
Vol 330-332 ◽  
pp. 897-900
Author(s):  
J.L. Xu ◽  
Khiam Aik Khor ◽  
W.N. Chen
Keyword(s):  
Cell Culture ◽  
Surface Morphology ◽  
Surface Composition ◽  
Plasma Sintering ◽  
Biomaterial Surfaces ◽  
Spark Plasma ◽  
Cellular Behaviors ◽  
Human Limb ◽  
Osteocalcin Production

Hydroxyapatite based biomaterials were prepared by a spark plasma sintering technology. The human limb-derived osteoblasts were cultured on the various biomaterial surfaces (HA, RF21, 1SiHA and 5SiHA) for up to two weeks to investigate the cellular behaviors. The bone gammacarboxyglutamic protein or osteocalcin in the medium were determined at different periods of cell culture. The results indicated that a combined effect of bioceramic surface composition and surface morphology had influenced the osteoblast behaviors. The amount of osteocalcin in the medium increased in the initial periods of culture but decreased in the late periods of culture.

scholarly journals Overexpression of FBXO17 Promotes the Proliferation, Migration and Invasion of Glioma Cells Through the Akt/GSK-3β/Snail Pathway

2021 ◽  
Vol 30 ◽  
pp. 096368972110073
Author(s):  
Ning Wang ◽  
Qian Song ◽  
Hai Yu ◽  
Gang Bao
Keyword(s):  
Cell Proliferation ◽  
Signaling Pathway ◽  
Glioma Cells ◽  
Migration And Invasion ◽  
Vimentin Expression ◽  
Protein Levels ◽  
Cellular Behaviors ◽  
Gsk 3Β

FBXO17 is a newly studied F-box protein associated with high-grade glioma. However, its exact role in glioma remains unclear. In the present study, we aimed to investigate the role of FBXO17 in glioma both in vitro and in vivo and explore the underlying mechanism. Our results showed that FBXO17 mRNA and protein levels were upregulated in glioma cells including U87, U251, SHG44, and U-118-MG cells as compared to the HA1800 cells. Downregulation of FBXO17 significantly suppressed the cellular behaviors of glioma cells including cell proliferation, migration, and invasion. In addition, FBXO17 knockdown induced E-cadherin expression and inhibited N-cadherin and vimentin expression at mRNA and protein levels in glioma cells. In contrast, overexpression of FBXO17 promoted cell proliferation, migration, invasion and EMT process. Furthermore, FBXO17 regulated the Akt/GSK-3β/snail signaling pathway in glioma cells with significant changes in the expression levels of p-Akt, p-GSK-3β and snail. Additionally, inhibition of Akt by LY294002 reversed the effects of FBXO17 overexpression on cellular behaviors of glioma cells. Finally, in vivo mouse xenograft assay proved that downregulation of FBXO17 suppresses the tumorigenesis of glioma. In conclusion, these findings demonstrated that FBXO17 acted as a promotor of glioma development via modulating Akt/GSK-3β/snail signaling pathway.

scholarly journals Mitotic kinesins in action: diffusive searching, directional switching, and ensemble coordination

2018 ◽  
Vol 29 (10) ◽  
pp. 1153-1156 ◽  
Author(s):  
Allison M. Gicking ◽  
Weihong Qiu ◽  
William O. Hancock
Keyword(s):  
Single Molecule ◽  
Mitotic Spindle ◽  
Cell Biology ◽  
Motor Systems ◽  
Microtubule Motors ◽  
Biophysical Studies ◽  
Cellular Behaviors ◽  
Mitotic Spindle Assembly

Mitotic spindle assembly requires the collective action of multiple microtubule motors that coordinate their activities in ensembles. However, despite significant advances in our understanding of mitotic kinesins at the single-motor level, multi-motor systems are challenging to reconstitute in vitro and thus less well understood. Recent findings highlighted in this perspective demonstrate how various properties of kinesin-5 and -14 motors—diffusive searching, directional switching, and multivalent interactions—allow them to achieve their physiological roles of cross-linking parallel microtubules and sliding antiparallel ones during cell division. Additionally, we highlight new experimental techniques that will help bridge the gap between in vitro biophysical studies and in vivo cell biology investigations and provide new insights into how specific single-molecule mechanisms generate complex cellular behaviors.

Effects of Superimposed Micro/Nano-Structured Titanium Alloy Surface on Cellular Behaviors In Vitro

2016 ◽  
Vol 18 (7) ◽  
pp. 1259-1266 ◽  
Author(s):  
Teng Wang ◽  
Yi Wan ◽  
Zhanqiang Liu
Keyword(s):  
Titanium Alloy ◽  
Alloy Surface ◽  
Cellular Behaviors

The Mechanical and Biochemical Environment Controls Cellular Differentiation During Muscle Regeneration

2011 ◽  
Author(s):  
Sarah Calve ◽  
Hans-Georg Simon
Keyword(s):  
Skeletal Muscle ◽  
Extracellular Matrix ◽  
Hyaluronic Acid ◽  
Muscle Regeneration ◽  
Cellular Differentiation ◽  
In Vitro Testing ◽  
Blastema Formation ◽  
Cellular Behaviors ◽  
Migration Inhibit

Urodele amphibians like the newt, are able to completely regenerate lost organs and appendages without scarring. Differentiated tissues are considered a reservoir for uncommitted blastema cells that participate in the regeneration of the lost structure. To determine the influence of the extracellular matrix (ECM) on the recruitment of progenitor cells from the skeletal muscle, we immunohistochemically mapped the limb in 3D and found that a transitional ECM rich in hyaluronic acid (HA), tenascin-C (TN) and fibronectin (FN) is dynamically expressed during the early stages of regeneration [1]. Functional in vitro testing of different ECM components on primary muscle cells revealed that HA and TN support myoblast migration, inhibit differentiation and enhance the fragmentation of multinucleate myotubes and production of viable mononucleate myoblasts, cellular behaviors necessary for blastema formation [1]. In contrast, myoblasts plated on matrices that mimic ECM around differentiated muscle (FN, Matrigel and laminin) induced both proliferation and fusion.

Sign in / Sign up

Export Citation Format

Share Document