Multi-Channeled Polymeric Microsystem for Studying the Impact of Surface Topography on Cell Adhesion and Motility

Abstract Background Overexpression of the EpCAM (epithelial cell adhesion molecule) in malignancies makes it an attractive target for passive immunotherapy in a wide range of carcinomas. In comparison with full-length antibodies, due to the small size, the scFvs (single-chain variable fragments) are more suitable for recombinant expression in E. coli (Escherichia coli). However, the proteins expressed in large amounts in E. coli tend to form inclusion bodies that need to be refolded which may result in poor recovery of bioactive proteins. Various engineered strains were shown to be able to alleviate the insolubility problem. Here, we studied the impact of four E. coli strains on the soluble level of anti-EpEX-scFv (anti-EpCAM extracellular domain-scFv) protein. Results Although results showed that the amount of soluble anti-EpEX-scFv obtained in BL21TM (DE3) (114.22 ± 3.47 mg/L) was significantly higher to those produced in the same condition in E. coli RosettaTM (DE3) (71.39 ± 0.31 mg/L), and OrigamiTM T7 (58.99 ± 0.44 mg/L) strains, it was not significantly different from that produced by E. coli SHuffleTM T7 (108.87 ± 2.71 mg/L). Furthermore, the highest volumetric productivity of protein reached 318.29 ± 26.38 mg/L in BL21TM (DE3). Conclusions Although BL21TM (DE3) can be a suitable strain for high-level production of anti-EpEX-scFv protein, due to higher solubility yield (about 55%), E. coli SHuffleTM T7 seems to be better candidate for soluble production of scfv compared to BL21TM (DE3) (solubility yield of about 30%).

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Impact of two disinfectants on detachment of Enterococcus faecalis from polythene in aquatic microcosm

Research in Biotechnology ◽

10.19071/rib.2016.v7.2981 ◽

2016 ◽

Vol 7 (1) ◽

Author(s):

C. Lontsi Djimeli ◽

A. Tamsa Arfao ◽

V Rossi ◽

N Nsulem ◽

V Raspal ◽

...

Keyword(s):

Hydrogen Peroxide ◽

Cell Adhesion ◽

Enterococcus Faecalis ◽

Sodium Hypochlorite ◽

Growth Phases ◽

Planktonic Cells ◽

Stationary Growth ◽

Experimental Conditions ◽

The Impact ◽

Aquatic Microcosm

After cell adhesion processes in microcosm, the impact of sodium hypochlorite (NaOCl) and hydrogen peroxide (H2O2) on the detachment of Enterococcus faecalis from polythene fragments immersed in water under stationary and dynamic conditions was assessed. The abundance of planktonic cells was also evaluated. The density of E. faecalis adhered in absence of disinfectant fluctuated between 2 and 4 units (Log CFU/cm2). After living in disinfected water, the density of E. faecalis remained adhered to polythene sometimes reached 2 units (Log CFU/Cm2). This highest abundance of cells remained adhered was recorded with cells coming from the lag, exponential and stationary growth phases in water treated with 0.5‰ NaOCl. In H2O2 disinfected water, the highest value was recorded at all cells growth phases with 5‰ H2O2 concentration. Adhered E. faecalis cells have been sometimes completely or partially decimated respectively by NaOCl and H2O2 treated water. Considering separately each experimental condition, it was noted that increasing the concentration of disinfectant caused a significant decrease (P≤0.01) in abundance of cells stay adhered after living in water disinfected by the two disinfectants. Changes in disinfectant concentrations in different experimental conditions had an impact on the detachment of E. faecalis cells from the substrates.

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Surface Modification of PLLA, PTFE and PVDF with Extreme Ultraviolet (EUV) to Enhance Cell Adhesion

International Journal of Molecular Sciences ◽

10.3390/ijms21249679 ◽

2020 ◽

Vol 21 (24) ◽

pp. 9679

Author(s):

Adam Lech ◽

Beata A. Butruk-Raszeja ◽

Tomasz Ciach ◽

Krystyna Lawniczak-Jablonska ◽

Piotr Kuzmiuk ◽

...

Keyword(s):

Surface Modification ◽

Cell Adhesion ◽

Endothelial Cell ◽

Vinylidene Fluoride ◽

Extreme Ultraviolet ◽

Cell Number ◽

Laboratory System ◽

Poly Vinylidene Fluoride ◽

The Impact ◽

Endothelial Cell Adhesion

Recently, extreme ultraviolet (EUV) radiation has been increasingly used to modify polymers. Properties such as the extremely short absorption lengths in polymers and the very strong interaction of EUV photons with materials may play a key role in achieving new biomaterials. The purpose of the study was to examine the impact of EUV radiation on cell adhesion to the surface of modified polymers that are widely used in medicine: poly(tetrafluoroethylene) (PTFE), poly (vinylidene fluoride) (PVDF), and poly-L-(lactic acid) (PLLA). After EUV surface modification, which has been performed using a home-made laboratory system, changes in surface wettability, morphology, chemical composition and cell adhesion polymers were analyzed. For each of the three polymers, the EUV radiation differently effects the process of endothelial cell adhesion, dependent of the parameters applied in the modification process. In the case of PVDF and PTFE, higher cell number and cellular coverage were obtained after EUV radiation with oxygen. In the case of PLLA, better results were obtained for EUV modification with nitrogen. For all three polymers tested, significant improvements in endothelial cell adhesion after EUV modification have been demonstrated.

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Quantitative Proteome Analysis of Atg5-Deficient Mouse Embryonic Fibroblasts Reveals the Range of the Autophagy-Modulated Basal Cellular Proteome

mSystems ◽

10.1128/msystems.00481-19 ◽

2019 ◽

Vol 4 (6) ◽

Cited By ~ 1

Author(s):

Kiran Bala Sharma ◽

Manish Sharma ◽

Suruchi Aggarwal ◽

Amit Kumar Yadav ◽

Shinjini Bhatnagar ◽

...

Keyword(s):

Cell Adhesion ◽

Inflammatory Response ◽

Transforming Growth Factor ◽

Proteome Analysis ◽

Interferon Response ◽

Type I ◽

Mouse Embryonic Fibroblasts ◽

Embryonic Fibroblasts ◽

The Impact

ABSTRACT Basal autophagy is crucial for maintenance of cellular homeostasis. ATG5 is an essential protein for autophagosome formation, and its depletion has been extensively used as a tool to disrupt autophagy. Here, we characterize the impact of Atg5 deficiency on the cellular proteome of mouse embryonic fibroblasts (MEFs). Using a tandem mass tagging (TMT)-based quantitative proteomics analysis, we observe that 14% of identified proteins show dysregulated levels in atg5−/− MEFs. These proteins were distributed across diverse biological processes, such as cell adhesion, development, differentiation, transport, metabolism, and immune responses. Several of the upregulated proteins were receptors involved in transforming growth factor β (TGF-β) signaling, JAK-STAT signaling, junction adhesion, and interferon/cytokine-receptor interactions and were validated as autophagy substrates. Nearly equal numbers of proteins, including several lysosomal proteins and enzymes, were downregulated, suggesting a complex role of autophagy/ATG5 in regulating their levels. The atg5−/− MEFs had lower levels of key immune sensors and effectors, including Toll-like receptor 2 (TLR2), interferon regulatory factor 3 (IRF3), IRF7, MLKL, and STAT1/3/5/6, which were restored by reexpression of ATG5. While these cells could efficiently mount a type I interferon response to the double-stranded RNA (dsRNA) mimic poly(I·C), they were compromised in their inflammatory response to the bacterial pathogen-associated molecular patterns (PAMPs) lipopolysaccharide (LPS) and Pam3CSK4. Transcriptional activation and secretion of interleukin-6 (IL-6) in these cells could be recovered by ATG5 expression, supporting the role of autophagy in the TLR2-induced inflammatory response. This study provides a key resource for understanding the effect of autophagy/ATG5 deficiency on the fibroblast proteome. IMPORTANCE Autophagy performs housekeeping functions for cells and maintains a functional mode by degrading damaged proteins and organelles and providing energy under starvation conditions. The process is tightly regulated by the evolutionarily conserved Atg genes, of which Atg5 is one such crucial mediator. Here, we have done a comprehensive quantitative proteome analysis of mouse embryonic fibroblasts that lack a functional autophagy pathway (Atg5 knockout). We observe that 14% of the identified cellular proteome is remodeled, and several proteins distributed across diverse cellular processes with functions in signaling, cell adhesion, development, and immunity show either higher or lower levels under autophagy-deficient conditions. These cells have lower levels of crucial immune proteins that are required to mount a protective inflammatory response. This study will serve as a valuable resource to determine the role of autophagy in modulating specific protein levels in cells.

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The Role of MicroRNAs in Epidermal Barrier

International Journal of Molecular Sciences ◽

10.3390/ijms21165781 ◽

2020 ◽

Vol 21 (16) ◽

pp. 5781

Author(s):

Ai-Young Lee

Keyword(s):

Cell Adhesion ◽

Critical Role ◽

Keratinocyte Differentiation ◽

Epidermal Barrier ◽

Barrier Integrity ◽

Skin Lipids ◽

Differentiation And Proliferation ◽

The Impact ◽

Cell Cell

MicroRNAs (miRNAs), which mostly cause target gene silencing via transcriptional repression and degradation of target mRNAs, regulate a plethora of cellular activities, such as cell growth, differentiation, development, and apoptosis. In the case of skin keratinocytes, the role of miRNA in epidermal barrier integrity has been identified. Based on the impact of key genetic and environmental factors on the integrity and maintenance of skin barrier, the association of miRNAs within epidermal cell differentiation and proliferation, cell–cell adhesion, and skin lipids is reviewed. The critical role of miRNAs in the epidermal barrier extends the use of miRNAs for control of relevant skin diseases such as atopic dermatitis, ichthyoses, and psoriasis via miRNA-based technologies. Most of the relevant miRNAs have been associated with keratinocyte differentiation and proliferation. Few studies have investigated the association of miRNAs with structural proteins of corneocytes and cornified envelopes, cell–cell adhesion, and skin lipids. Further studies investigating the association between regulatory and structural components of epidermal barrier and miRNAs are needed to elucidate the role of miRNAs in epidermal barrier integrity and their clinical implications.

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The effects of surface topography of nanostructure arrays on cell adhesion

Physical Chemistry Chemical Physics ◽

10.1039/c8cp03538e ◽

2018 ◽

Vol 20 (35) ◽

pp. 22946-22951 ◽

Cited By ~ 12

Author(s):

Jing Zhou ◽

Xiaowei Zhang ◽

Jizheng Sun ◽

Zechun Dang ◽

Jinqi Li ◽

...

Keyword(s):

Cell Adhesion ◽

Density Distribution ◽

Surface Topography ◽

Thermodynamic Model ◽

Surface Density ◽

Distribution Density ◽

Small Radius ◽

Surface Distribution ◽

Nanostructure Arrays

The effects of geometry and surface density distribution of nanopillars on cell adhesion studied by a quantitative thermodynamic model showed that high (low) surface distribution density and large (small) radius result in the “Top” (“Bottom”) mode.

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Investigation of Tool Errors and Their Influences on Tooth Surface Topography for Face-Hobbed Hypoid Gears

Journal of Mechanical Design ◽

10.1115/1.4044745 ◽

2019 ◽

Vol 142 (4) ◽

Cited By ~ 4

Author(s):

Chengcheng Liang ◽

Chaosheng Song ◽

Caichao Zhu ◽

Yawen Wang ◽

Siyuan Liu ◽

...

Keyword(s):

Surface Topography ◽

Rake Angle ◽

Tooth Surface ◽

Maximum Deviation ◽

Angle Error ◽

Hypoid Gears ◽

Pressure Angle ◽

Deviation Analysis ◽

Surface Deviation ◽

The Impact

Abstract Tool errors are inevitable in an actual gear-manufacturing environment and may directly affect the accuracy of machined tooth surfaces. In this paper, tool errors including spheric radius, pressure angle, rake angle, regrind angle, and cutting side relief angle errors for three-face blade are defined and considered to establish the accurate tooth surface mathematical model for face-hobbed hypoid gears based on the manufacturing process and the meshing theory. The simulation flowchart for tooth surface modeling and tooth surface topography deviation analysis are proposed and performed. Results show that the tooth surface deviation is positive with positive spheric radius and rake angle errors and contrary results can be found for other three tool errors. In addition, the impact of the pressure angle error is the strongest. In addition, the rake angle error has the weakest effect and the influence of spheric radius error on the tooth surface deviation is unsubstantial. For location of tooth surface deviation, the maximum deviation is at the top on the heel and the minimum deviation is at the middle on the toe for spheric radius error. The maximum and minimum deviations are at the top and the middle tooth on the heel for other factors, respectively.

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Effects of cutter path orientations on milling force, temperature, and surface integrity when ball end milling of TC17 alloy

Proceedings of the Institution of Mechanical Engineers Part B Journal of Engineering Manufacture ◽

10.1177/0954405420971070 ◽

2020 ◽

pp. 095440542097107

Author(s):

Xuehong Shen ◽

Dinghua Zhang ◽

Liang Tan

Keyword(s):

Residual Stress ◽

Surface Roughness ◽

Surface Topography ◽

Surface Integrity ◽

End Milling ◽

Layer Depth ◽

Milling Force ◽

Mechanical Coupling ◽

Cutter Path ◽

The Impact

To explore the effects of cutter path orientations on milling force, temperature, and surface integrity, end ball milling experiments of TC17 titanium alloy were accomplished derived from different cutter path orientations. The experiment results of milling force and temperature were obtained. Combining with the thermo-mechanical coupling, this paper analyzes the impact of the cutter path orientations on the surface roughness, surface topography, in-depth residual stress, microhardness distributions, and microstructure. The results indicate that the maximum milling force is 224.24 N and the temperature is 672°C under vertical downward milling path, while horizontal downward orientation provides the lowest cutting force of 81.12 N and temperature of 493°C. The surface topography of the four cutter path orientations is basin-like shape, and the minimum surface roughness of 1.128 µm is achieved under vertical upward mode. Moreover, the maximum compressive residual stress of −491.8 MPa and the maximum residual stress layer depth of 45 µm are acquired under vertical downward milling. The maximum microhardness can arrive at 390 HV0.025 under the vertical path. Additionally, the transformation of the material microstructure remains elongated, bent, and fractured. The maximum plastic deformation layer depth is 44 µm under vertical downward milling path.

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The Impact of Spaceflight and Simulated Microgravity on Cell Adhesion

International Journal of Molecular Sciences ◽

10.3390/ijms21093031 ◽

2020 ◽

Vol 21 (9) ◽

pp. 3031 ◽

Cited By ~ 2

Author(s):

Xiao Lin ◽

Kewen Zhang ◽

Daixu Wei ◽

Ye Tian ◽

Yongguang Gao ◽

...

Keyword(s):

Cell Adhesion ◽

Mammalian Cells ◽

Simulated Microgravity ◽

General Term ◽

Cellular Adhesion ◽

Immunoglobulin Superfamily ◽

Adhesion Properties ◽

Cellular Adhesion Molecule ◽

The Impact ◽

Cell Cell

Microgravity induces a number of significant physiological changes in the cardiovascular, nervous, immune systems, as well as the bone tissue of astronauts. Changes in cell adhesion properties are one aspect affected during long-term spaceflights in mammalian cells. Cellular adhesion behaviors can be divided into cell–cell and cell–matrix adhesion. These behaviors trigger cell–cell recognition, conjugation, migration, cytoskeletal rearrangement, and signal transduction. Cellular adhesion molecule (CAM) is a general term for macromolecules that mediate the contact and binding between cells or between cells and the extracellular matrix (ECM). In this review, we summarize the four major classes of adhesion molecules that regulate cell adhesion, including integrins, immunoglobulin superfamily (Ig-SF), cadherins, and selectin. Moreover, we discuss the effects of spaceflight and simulated microgravity on the adhesion of endothelial cells, immune cells, tumor cells, stem cells, osteoblasts, muscle cells, and other types of cells. Further studies on the effects of microgravity on cell adhesion and the corresponding physiological behaviors may help increase the safety and improve the health of astronauts in space.

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In Vitro and In Vivo Studies of Biodegradability and Biocompatibility of Poly(εCL)-b-Poly(EtOEP)-Based Films

Polymers ◽

10.3390/polym12123039 ◽

2020 ◽

Vol 12 (12) ◽

pp. 3039

Author(s):

Ilya Nifant’ev ◽

Andrey Shlyakhtin ◽

Pavel Komarov ◽

Alexander Tavtorkin ◽

Evgeniya Kananykhina ◽

...

Keyword(s):

Cell Adhesion ◽

Block Copolymers ◽

Polymer Films ◽

Hydrolytic Stability ◽

Polymer Materials ◽

In Vivo Studies ◽

Cytotoxicity Test ◽

The Impact

The control of surface bioadhesive properties of the subcutaneous implants is essential for the development of biosensors and controlled drug release devices. Poly(alkyl ethylene phosphate)-based (co)polymers are structurally versatile, biocompatible and biodegradable, and may be regarded as an alternative to poly(ethylene glycol) (PEG) copolymers in the creation of antiadhesive materials. The present work reports the synthesis of block copolymers of ε-caprolactone (εCL) and 2-ethoxy-1,3,2-dioxaphospholane-2-oxide (ethyl ethylene phosphate, EtOEP) with different content of EtOEP fragments, preparation of polymer films, and the results of the study of the impact of EtOEP/εCL ratio on the hydrophilicity (contact angle of wetting), hydrolytic stability, cytotoxicity, protein and cell adhesion, and cell proliferation using umbilical cord multipotent stem cells. It was found that the increase of EtOEP/εCL ratio results in increase of hydrophilicity of the polymer films with lowering of the protein and cell adhesion. MTT cytotoxicity test showed no significant deviations in toxicity of poly(εCL) and poly(εCL)-b-poly(EtOEP)-based films. The influence of the length of poly(EtOEP)chain in block-copolymers on fibrotic reactions was analyzed using subcutaneous implantation experiments (Wistar line rats), the increase of the width of the fibrous capsule correlated with higher EtOEP/εCL ratio. However, the copolymer-based film with highest content of polyphosphate had been subjected to faster degradation with a formation of developed contact surface of poly(εCL). The rate of the degradation of polyphosphate in vivo was significantly higher than the rate of the degradation of polyphosphate in vitro, which only confirms an objective value of in vivo experiments in the development of polymer materials for biomedical applications.

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