scholarly journals A durable and biocompatible ascorbic acid-based covalent coating method of polydimethylsiloxane for dynamic cell culture

2017 ◽  
Vol 14 (132) ◽  
pp. 20170318 ◽  
Author(s):  
Joni Leivo ◽  
Sanni Virjula ◽  
Sari Vanhatupa ◽  
Kimmo Kartasalo ◽  
Joose Kreutzer ◽  
...  

Polydimethylsiloxane (PDMS) is widely used in dynamic biological microfluidic applications. As a highly hydrophobic material, native PDMS does not support cell attachment and culture, especially in dynamic conditions. Previous covalent coating methods use glutaraldehyde (GA) which, however, is cytotoxic. This paper introduces a novel and simple method for binding collagen type I covalently on PDMS using ascorbic acid (AA) as a cross-linker instead of GA. We compare the novel method against physisorption and GA cross-linker-based methods. The coatings are characterized by immunostaining, contact angle measurement, atomic force microscopy and infrared spectroscopy, and evaluated in static and stretched human adipose stem cell (hASC) cultures up to 13 days. We found that AA can replace GA as a cross-linker in the covalent coating method and that the coating is durable after sonication and after 6 days of stretching. Furthermore, we show that hASCs attach and proliferate better on AA cross-linked samples compared with physisorbed or GA-based methods. Thus, in this paper, we provide a new PDMS coating method for studying cells, such as hASCs, in static and dynamic conditions. The proposed method is an important step in the development of PDMS-based devices in cell and tissue engineering applications.

2020 ◽  
Vol 12 (1) ◽  
Author(s):  
Chia-Yu Chen ◽  
David. M. Kim ◽  
Cliff Lee ◽  
John Da Silva ◽  
Shigemi Nagai ◽  
...  

AbstractThe aim of this study was to evaluate the biological efficacy of a unique perpendicular protrusion of type-I collagen (Col-I) from TiO2 nanotubes (NT-EPF surface). We hypothesized that the NT-EPF surface would play bifunctional roles in stimulating platelet-mediated fibroblast recruitment and anchoring fibroblast-derived Col-I to form a perpendicular collagen assembly, mimicking the connective tissue attachment around natural teeth for the long-term maintenance of dental implants. Ti surface modification was accomplished in two steps. First, TiO2 nanotubes (NT) array was fabricated via anodization. Diameters and depths of NTs were controlled by applied voltage and duration. Subsequently, an electrophoretic fusion (EPF) method was applied to fuse Col-I into nanotube arrays in a perpendicular fashion. Surface wettability was assessed by contact angle measurement. The bioactivity of modified TiO2 surfaces was evaluated in terms of NIH3T3 fibroblast attachment, platelet activation, and collagen extension. Early attachment, aggregation, and activation of platelets as well as release of platelet-related growth factors were demonstrated on NT-EPF surfaces. Platelet-mediated NIH3T3 cells migration toward NT-EPF was significantly increased and the attached cells showed a typical fibrous morphology with elongated spindle shape. A direct linkage between pseudopod-like processes of fibroblasts to NT-EPF surfaces was observed. Furthermore, the engineered EPF collagen protrusion linked with cell-derived collagen in a perpendicular fashion. Within the limitation of this in vitro study, the TiO2 nanotube with perpendicular Col-I surface (NT-EPF) promoted better cell attachment, induced a strong platelet activation which suggested the ability to create a more robust soft tissue seal.


2007 ◽  
Vol 342-343 ◽  
pp. 353-356 ◽  
Author(s):  
Jung Bok Lee ◽  
Seong Mi Yu ◽  
Sang Gil Lee ◽  
Jae Bong Choi ◽  
Jeong Koo Kim

PLGA (75:25)/hydroxyapatite (HA) composite films were fabricated by solvent-casting method to investigate the effect of various hydroxyapatite content ratio to the PLGA film for cellular attachment and proliferation. Mechanical property of the composite film was characterized by tensile test. The ultimate tensile strength of 10% HA content film was two folds higher than control group. The surface of the film was characterized by contact angle measurement. The PLGA/HA composite film was more hydrophilic than control film. In vitro chondrocyte responses to the composite films were measured by cellular attachment and proliferation test. The attached and proliferated cells were significantly higher on PLGA/HA (10%) composite film than control group (1.44 times higher in attachment test and 1.31 times higher for 6th-day at culture in proliferation assaying, p<0.05). Base on these finding, the PLGA/HA (10%) composite was effective for the cell attachment for the initial stage of cultivation and cell proliferation.


Materials ◽  
2019 ◽  
Vol 12 (4) ◽  
pp. 644 ◽  
Author(s):  
Wei-Chih Lin ◽  
Nur Mohd Razali

Surface wettability plays an important role in determining the function of a wound dressing. Dressings with hydrophobic surfaces are suitable for bacterial adsorption, however, a hydrophilic surface is needed to improve cell attachment for most anchorage-dependent cell types. Furthermore, the hydrophobicity/hydrophilicity of the surface can be used to direct cellular processes such as cell initial attachment, adhesion, and migration during wound healing. Thus, a surface with an ability to switch their surface wettability improves the practicality of the dressing. In this study, we propose a temporary surface wettability tuning for surface patterning utilizing plasma treatment. Polycaprolactone (PCL) and polydimethylsiloxane (PDMS) surfaces were treated with tetrafluoromethane (CF4), sulphur hexafluoride (SF6), and oxygen (O2) plasma, and the effects on the surface wettability, roughness, and chemical composition were investigated. Based on the contact angle measurement, CF4 plasma altered surface wettability of PCL and PDMS films to hydrophobic and hydrophilic, respectively. After CF4 treatment, better attachment of primary mouse embryonic fibroblast cell (3T3) was observed on the treated PDMS surface. Embedding PCL into PDMS generated a hydrophobic-hydrophilic pattern mixture surface, which offers great potential in the tissue engineering field such as cell patterning and guidance.


NANO ◽  
2011 ◽  
Vol 06 (03) ◽  
pp. 265-269 ◽  
Author(s):  
QUNBING ZHANG ◽  
SHIHE CAO ◽  
JUN WANG

ZnO films with well-aligned hierarchical structures have been successfully synthesized at moderate temperatures using a simple catalyst-free hydrothermal process. The synthesized ZnO films are found to be single-phase, with a hexagonal wurtzite-type structure. Scanning electron microscopy images show that the well-aligned hierarchical structures are assembled with interlaced parallel sheets grown on the (400) silica surface. The water contact angle measurement indicates that the water on the films has a contact angle of about 156.3°. This clearly demonstrates that the ZnO films synthesized by this simple method have superhydrophobic properties and may be important for applications in self-cleaning surfaces, biology, and so on.


1987 ◽  
Vol 66 (9) ◽  
pp. 1449-1455 ◽  
Author(s):  
S. Pitaru ◽  
M. Soldinger ◽  
D. Madgar ◽  
Z. Metzger

The purpose of this study was to assess the effect of endotoxin adsorbed to dental surfaces and to collagen type I on the migration, attachment, and orientation of human gingival fibroblasts (HGF). Transversely cut porcine tooth root slices (RS), 200 μm thick, were prepared. Half of the RS obtained were partially demineralized in EDTA. Half of the demineralized and non-demineralized RS were incubated with 400 μg/mL of endotoxin for 24 hr, whereas the other half were maintained in PBS and served as controls. Experimental and control RS were placed on confluent layers of HFG and cultured for six days. Cell migration toward and cell attachment to the periphery of the RS and the formation of oriented cell sheets were assessed by means of photographic techniques. Additionally, six-day-old cultures were fixed and processed for SEM observation. In separate experiments, the effect of endotoxin on cell attachment to collagen type I and on contraction of three-dimensional collagen gels was assessed. It was found that: (i) bacterial endotoxin inhibited migration and attachment of HGF to both demineralized and non-demineralized cementum and interfered with the development of oriented cellular structure ; (ii) the inhibitory effect was significantly more pronounced for non-demineralized than for demineralized cementum; (iii) the morphology of HGF attached to endotoxin-treated dental surfaces was altered compared with that of their controls; and (iv) bacterial endotoxin inhibited cell attachment to collagen type I and delayed the contraction of collagen gel.


2013 ◽  
Vol 785-786 ◽  
pp. 1547-1550
Author(s):  
Guang Fen Li ◽  
Jin Chao Zhang ◽  
Xu Dong Sun

Here a simple method was developed to fabricate hydrophilic Polyethersulphone film via a sol-gel process. The correspondent hydrophilicity was evaluated by infrared spectral analysis, X-ray photoelectron spectroscopy, the contact angle measurement, atomic force microscope and scanning electron microscope analysis, respectively. Both FTIR and XPS analysis indicated that the film surfaces have a relatively dense sol layer, which favors to become hydrophilic. AFM analysis demonstrated that the higher hydrophilicity was mainly attributed to the surface roughness, while SEM images show that the micro/nanometer crater-like protrusions appears on the film surfaces, whereas the spongy structures & the finger-like structures appear in cortex and intermediate layer respectively. This leads to the hydrophilic film forming after film being treated by sol-gel method.


2011 ◽  
Vol 9 (6) ◽  
pp. 1039-1045 ◽  
Author(s):  
Beata Butruk ◽  
Paulina Ziętek ◽  
Tomasz Ciach

AbstractThe aim of this study was to develop a method of manufacturing versatile hydrophobic coatings for polymers. Authors present a simple technique of polyurethane (PU) surface modification with covalently attached silicones (PDMS) or fluorocarbons (PFC). Diisocyanates were applied as linker molecules. The obtained coatings were characterized using spectroscopic analysis (FTIR), scanning acoustic microscopy (SAM) and water contact angle measurements. FTIR analysis revealed high efficiency of grafting reaction. The results of contact angle measurement indicated significant increase of hydrophobicity — from 66° (unmodified PU) to 113° (PU grafted with PDMS) and 118° (PU grafted with PFC). Acoustic microscopy analysis confirmed satisfactory homogeneity and smoothness of the fabricated layers. In vitro cell tests revealed non-adherent properties of the surfaces. Both, MTT assay and fluorescence staining confirmed non-cytotoxicity of the coatings, which makes them potential candidates for use in biomedical applications.


Development ◽  
1991 ◽  
Vol 113 (3) ◽  
pp. 1007-1016 ◽  
Author(s):  
S. Hirano ◽  
K. Ui ◽  
T. Miyake ◽  
T. Uemura ◽  
M. Takeichi

Using the Drosophila cell line MLDmBG-1, a monoclonal antibody aBG-1 that can inhibit not only cell clumping but also cell spreading was generated. This antibody immunoprecipitates a complex of molecules consisting of a major 120 × 10(3) Mr and other components. To characterize the 120 × 10(3) Mr component, we purified it, generated antibodies to it, and cloned its cDNA. Sequencing of this cDNA suggests that the 120 × 10(3) Mr molecule is identical to PS beta, a beta chain of Drosophila integrins. The other components immunoprecipitated included two alpha chains of Drosophila integrins, PS1 alpha and PS2 alpha, as revealed using specific antibodies to these molecules. These suggest that aBG-1 recognizes the PS beta associated with PS1 alpha or PS2 alpha. However, immunostaining of embryos and larvae with aBG-1 showed that the staining pattern is similar to that for PS2 alpha but not for PS beta, suggesting that the antibody preferentially recognizes the PS beta associated with particular alpha chains in situ. We then attempted to characterize the ligands for these integrin complexes, using culture dishes coated with various vertebrate matrix proteins. These cells spread very well on dishes coated with vitronectin and, to a lesser extent, on those with fibronectin. This spreading was partially inhibited by aBG-1, but not by other control antibodies or RGD peptides. The cell attachment to these substrata was not affected by the antibody. The cells also can attach to dishes coated with laminin but without spreading, and this attachment was not inhibited by aBG-1. Furthermore, they do not attach to dishes coated with collagen type I, type IV, and fibrinogen. These results indicate that Drosophila PS integrins can recognize vertebrate vitronectin, and also fibronectin with a weaker affinity, at sites other than RGD sequences, and thus can function in cell-substratum adhesion.


1993 ◽  
Vol 105 (3) ◽  
pp. 739-751 ◽  
Author(s):  
H. Grenz ◽  
S. Carbonetto ◽  
S.L. Goodman

The movement of integrins into focal adhesive structures accompanies cell attachment to extracellular matrix. The kinetics of incorporation of integrins into focal contacts was studied during attachment to matrix of mesangial cells of the kidney glomerulus. On collagen, fibronectin, laminin and vitronectin, the number and intensity of talin-focal contacts increased with time. Talin-containing focal contacts were present in mesangial cells within 2 h of plating and in control cells (HT1080 and Rugli) within 1 h. Integrin alpha-chains colocalized with talin, dependent on the matrix substrate. The attachment, spreading and organization of integrin into focal contacts was not affected when endogenous protein synthesis was suppressed with cycloheximide. In Rugli, alpha 1 beta 1 organized into focal contacts on collagen and laminin, while in HT1080 alpha 2 beta 1 organized on collagen type I, alpha 5 beta 1 on fibronectin, alpha 6 beta 1 on laminin, and alpha 3 beta 1 and alpha 4 beta 1 were diffusely distributed on all substrates. These distributions mirrored the usage and expression patterns previously established for integrins in these cells and was as predicted from the literature. In mesangial cells, however, alpha 3 beta 1 was also organized into prominent focal contact arrays on collagen, fibronectin, EHS and human placental laminins, but not on vitronectin, while alpha 6 beta 1 was not organized. Initial attachment and spreading of mesangial cells was absolutely dependent on divalent cations. Mg2+ and Mn2+ supported attachment on all substrates, while Ca2+ stimulated attachment on laminin (E8), fibronectin and vitronectin. The data suggest that the functional integrins on mesangial cells include alpha 1 beta 1 (on collagen and laminin) alpha 2 beta 1 (on collagen), alpha 5 beta 1 (on fibronectin) and alpha V beta 3 (on vitronectin). However, mesangial cells do not use alpha 6 beta 1 on laminin, and the data support a role for alpha 3 beta 1 as putative receptor for fibronectin, collagen and laminin.


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