Dehydration of Glass Surfaces Studied by Contact Angle Measurements

Engländer, Tino; Wiegel, D; Naji, Lama; Arnold, Klaus

doi:10.1006/jcis.1996.0260

Cited by 26 publications

(14 citation statements)

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“…17 As such, tissue culture polystyrene and glass are both hydrophilic and have similar wetting properties ͑water-in-air contact angle of TCPS Յ 29°C and of glass Յ29°C͒. 18,19 Despite those similarities, hES cells behave differently when they are grown on Matrigel adsorbed onto each surface. In this work, the room temperature gelling of Matrigel was replicated inside a quartz crystal microbalance.…”

Section: Introductionmentioning

confidence: 99%

Characterization of Matrigel interfaces during defined human embryonic stem cell culture

2009

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Differences in attachment, proliferation, and differentiation were measured for human embryonic stem (hES) cells cultured on various substrata coated with Matrigeltm, a blend of extracellular matrix proteins derived from murine tumor cells. The authors observed that hES cells attach and grow poorly on Matrigel adsorbed onto polystyrene, while they proliferate when exposed to Matrigel adsorbed onto glass or oxygen plasma treated polystyrene (e.g., “tissue culture” treated polystyrene). Furthermore, hES cells grown on the Matrigel-coated tissue culture polystyrene are less likely to differentiate than those grown on the Matrigel-coated glass. To assess the mechanism for these observations, they replicated the cell culture interface in a quartz crystal microbalance with dissipation monitoring. In addition, they used ellipsometry and scanning electron microscopy to determine the thickness and topography of Matrigel on the varying surfaces. Matrigel formed a viscoelastic multilayer with similar thickness on all three surfaces; however, the network structure was different, where the adsorbed proteins formed a globular network on polystyrene, and fibrillar networks on the hydrophilic substrates. Matrigel networks on glass were denser than on oxygen plasma treated polystyrene, suggesting that the density and structure of the Matrigel network affects stem cell differentiation, where a denser network promoted uncontrolled hES cell differentiation and did not maintain the self-renewal phenotype.

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Section: Introductionmentioning

confidence: 99%

Characterization of Matrigel interfaces during defined human embryonic stem cell culture

2009

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“…Under hydrophobic conditions (assuming a θ s ≈ θ v = 140° between PDMS and water) 21 , and varying the geometries of the channel width and height, we calculated higher pressure differences (Figure 2E) which scaled linearly if either parameter was changed. As height or width increased from 50–100 μm, the pressure differences dropped drastically but eventually leveled off when past 200 μm.…”

Section: Resultsmentioning

confidence: 99%

Engineering microscale cellular niches for three-dimensional multicellular co-cultures

et al. 2009

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Summary Modeling the in vivo microenvironment typically involves placing cells in a three-dimensional (3D) extracellular matrix (ECM) in physiologically relevant context with respect to other cells. The mechanical and chemical features of 3D microenvironments play important roles in tissue engineering, tumor growth and metastasis, and in defining stem cell niches, and it is increasingly recognized that cells behave much differently when surrounded by a 3D ECM than when anchored to a 2D substrate. To create microenvironments that more closely mimic in vivo settings, here we describe a novel microfluidic device that allows multiple discrete constructs of 3D cell-laden hydrogels to be patterned in a sequence of simple steps. The microfluidic platform allows for real time imaging of the interactions between multiple cell types exposed to both autocrine and paracrine signaling molecules, all within a 3D ECM environment. Detailed modeling determined that surface tension, hydrophobic interactions, and spatial geometry were important factors in containing the gels within distinct separate channels during the filling process. This allowed us to pattern multiple gel types side-by-side and pattern 3D gels spatially with tight dimensional control. Cells embedded in gels could be patterned by culturing MDA-MB-231 metastatic breast cancer cells and RAW 264.1 macrophage cells within distinct collagen type I and Matrigel ECM environments, respectively. Over a 7 day culture experiment, RAW cells invaded into neighboring gels containing MDA-MB-231 cells, but not into gels lacking cells. These studies demonstrate the versatility and potential of this new microfluidic platform to engineer 3D microscale architectures to investigate cell-cell and cell-matrix interactions.

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“…The stand is a cube-shaped structure with open walls in all faces. Therefore, the movement of the texture analyzer arm should be controlled to avoid breaking the glass container of glass surfaces indicate an increase in contact angle as a function of water drying time (27). These findings may indicate that the glass probe needs to be in contact with aqueous solutions for a certain period of time prior to the analysis of surface tension.…”

Section: Resultsmentioning

confidence: 99%

Application of a Pull on a Disk Method to Measure Surface Tension of Liquids

2012

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Abstract. The intrinsic property of liquids is a vital indicator of formulation performance and stability. Therefore, investigation of the interfacial phenomenon of surface tension is a routine procedure in the development of products in a wide variety of areas including foods, pharmaceuticals, cosmetics, and painting technologies. We hypothesize that studies related to the maximum pull on a rod can be extrapolated to disk geometry and applied to measure surface tension using a texture analyzer. A glass disk probe was attached to the arm of a texture analyzer and pulled from the liquid surface. The maximum force of detachment was used to calculate surface tension extrapolating from the theory of maximum pull on a rod. The surface tension of water, ethanol, and a hydroalcoholic solution was measured and compared with literature values to validate this hypothesis. The calculated values of surface tension for the liquids studied were within 5% of the reported values. Probe diameter appears to have an important role on surface tension accuracy compared with literature values. Slight discrepancies can be attributed to temperature control and leveling of liquid surface, although still in accordance with the reported values of surface tension measured using different methods. This study presents a simple, precise, and quick method to determine the surface tension of liquids from the maximum pull on a disk. Further studies are warranted to determine the optimum glass disk probe diameter for better accuracy.

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Dehydration of Glass Surfaces Studied by Contact Angle Measurements

Cited by 26 publications

References 0 publications

Characterization of Matrigel interfaces during defined human embryonic stem cell culture

Characterization of Matrigel interfaces during defined human embryonic stem cell culture

Engineering microscale cellular niches for three-dimensional multicellular co-cultures

Application of a Pull on a Disk Method to Measure Surface Tension of Liquids

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