Single-walled carbon nanotubes are novel molecular-scale wires having excellent anti-adhesion properties with regard to platelets.
On the other hand, chitosan is a partially de-acetylated derivative of chitin that has a critical role in cell attachment
and growth. The aim of this study was to investigate how carbon nanotubes improve the blood biocompatibility of chitosan film.
We prepared composite films with various concentrations of chitosan/carbon nanotubes (CS/CNTs) (1.3–6.3 wt%). The sample surfaces
were characterized by Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM), and contact
angle measurements. The surface characterization revealed that the surface of the CS/CNTs composite film became more hydrophobic
with increasing amounts of CNTs. Cell attachment tests using bovine aortic endothelial cells (BAECs) indicated that CS/CNTs
composite films retained their cell adhesion ability. The blood compatibility of the CS/CNTs composite films was evaluated
using the blood platelet adhesion and activation tests in vitro. Platelet adhesion results confirmed that platelet adhesion
and the formation of a platelet network were inhibited on composite films with higher concentrations of CNTs (5.1 wt%). Our
experimental results show that the novel composite film containing CS/CNTs possesses two paradoxical characteristics, namely,
good adherence of endothelial cells and minimum adherence and activation of platelets, making this film a promising antithrombogenic
material for use in the biomedical field. 相似文献
The chemical strategy presented herein is the nondestructive preparation of resorbable polymer scaffolds with heparin covalently bonded to the surface and an osteoinductive growth factor, recombinant human bone morphogenetic protein-2, immobilized in the heparin layer. The coupling scheme involves functionalization of surfaces by grafting in the vapor phase with poly( l-lactide) and poly(-caprolactone) films chosen as representative substrates. The biocompatibility of functionalized surfaces was verified by a much improved attachment and proliferation of mesenchymal stem cells (MSC). 相似文献
AIM: To establish the potential of poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHBHHx) as a material for tendon repair. METHODS: The biocompatibility of PHBHHx with both rat tenocytes (rT) and human mesenchymal stem cells (hMSC) was explored by monitoring adhesive characteristics on films of varying weight/volume ratios coupled to a culture atmosphere of either 21% O2 (air) or 2% O2 (physiological normoxia). The diameter and stiffness of PHBHHx films was established using optical coherence tomography and mechanical testing, respectively. RESULTS: Film thickness correlated directly with weight/volume PHBHHx (r2 = 0.9473) ranging from 0.1 mm (0.8% weight/volume) to 0.19 mm (2.4% weight/volume). Film stiffness on the other hand displayed a biphasic response which increased rapidly at values 1.6% weight/volume. Optimal cell attachment of rT required films of ≥ 1.6% and ≥ 2.0% weight/volume PHBHHx in 2% O2 and 21% O2 respectively. A qualitative adhesion increase was noted for hMSC in films ≥ 1.2% weight/volume, becoming significant at 2% weight/volume in 2% O2. An increase in cell adhesion was also noted with ≥ 2% weight/volume PHBHHx in 21% O2. Cell migration into films was not observed. CONCLUSION: This evaluation demonstrates that PHBHHx is a suitable polymer for future cell/polymer replacement strategies in tendon repair. 相似文献
We demonstrate a method to fabricate graphene microelectrode arrays (MEAs) using a simple and inexpensive method to solve the problem of opaque electrode positions in traditional MEAs, while keeping good biocompatibility. To study the interface differences between graphene–electrolyte and gold–electrolyte, graphene and gold electrodes with a large area were fabricated. According to the simulation results of electrochemical impedances, the gold–electrolyte interface can be described as a classical double-layer structure, while the graphene–electrolyte interface can be explained by a modified double-layer theory. Furthermore, using graphene MEAs, we detected the neural activities of neurons dissociated from Wistar rats (embryonic day 18). The signal-to-noise ratio of the detected signal was 10.31 ± 1.2, which is comparable to those of MEAs made with other materials. The long-term stability of the MEAs is demonstrated by comparing differences in Bode diagrams taken before and after cell culturing. 相似文献
Poypyrrole(Ppy)films were prepared at 1×10-3 mA/cm2 electropolymerization current density on indium-tin oxide(ITO)substrate. The Ppy films were wall-distributed, translucent, stable and insoluble. Moreover, they can be sterilized by steam disinfection. Rat hepatic cells were cultured on these films. The results show that Ppy films have good biocompatibility and they can accelerate cell growth under electrical stimulation. The cells on Ppy films reach the largest cell density earlier than the cells on tissue culture polystyrene(TCPS). Furthermore, rat hepatic cells can generate on Ppy films. The cells on Ppy films grow faster and enter logarithmic growth phase earlier than those on TCPS. 相似文献
To investigate the mechanisms of cell protection provided by medium additives against animal cell injury in sparged bioreactors, we have analyzed the effect of various additives on the cell-to-bubble attachment process using CHO cells in suspension. Cell-to-bubble attachment was examined using three experimental techniques: (1) cell-bubble induction time analysis (cell-to-bubble attachment times); (2) forming thin liquid films and observing the movement and location of cells in the thin films; and (3) foam flotation experiments. The induction times we measured for the various additives are as follows: no additive (50 to 500 ms), polyvinyl pyrrolidone (PVP: 20 to 500 ms), polyethylene glycol (PEG: 200 to 1000 ms), 3% serum (500 to 1000 ms), polyvinyl alcohol (PVA: 2 to 10 s), Pluronic F68 (5 to 20 s), and Methocel (20 to 60 s). In the thin film formation experiments, cells in medium with either F68, PVA, or Methocel quickly flowed out of draining thin liquid films and entered the plateau border. When using media with no additive or with serum, the flow of cells out of the thin liquid film and film drainage were slower than for media containing Pluronic F68. PVA, or Methocel. With PVP and PEG, the thin film drainage was much slower and cells remained trapped in the film. For the foam flotation experiments, a separation factor (ratio of cell concentration in the foam catch to that in the bubble column) was determined for the various additives. In the order of increasing separation factors (i.e., increasing cell attachment to bubbles), the additives are as follows: Methocel, PVA, Pluronic F68, 3% serum, serum-free medium with no additives, PEG, and PVP. Based on the results of these three different cell-to-bubble attachment experiments, we have classified the cell-protecting additives into three groups: (1) Pluronic F68, PVA, and Methocel (reduced cell-to-bubble attachment); (2) PEG and PVP (high or increased cell-to-bubble attachment); and (3) FBS (reduced cell attachment butslower drainage films compared with F68, PVA, and Methocel with some cell entrapment in those films). These phenomena are discussed in relation to the interfacial properties of the media reported in a companion Study (this issue). (c) 1995 John Wiley & Sons Inc. 相似文献
Any biomaterial implanted within the human body is influenced by the interactions that take place between its surface and
the surrounding biological milieu. These interactions are known to influence the tissue interface dynamic, and thus act to
emphasize the need to study cell-surface interactions as part of any biomaterial design process. The work described here investigates
the relationship between human osteoblast attachment, spreading and focal contact formation on selected surfaces using immunostaining
and digital image processing for vinculin, a key focal adhesion component. Our observations show that a relationship exists
between levels of cell attachment, the degree of vinculin-associated plaque formation and biocompatibility. It also suggests
that cell adhesion is not indicative of how supportive a substrate is to cell spreading, and that cell spreading does not
correlate with focal contact formation. 相似文献
Human Umbilical Vein Endothelial Cell (HUVEC) growth on chitosan films and its enzymatically functionalized derivatives films with ferulic acid (FA) and ethyl ferulate (EF) was assessed by evaluating cell adhesion, morphology and cell viability. The results indicated that chitosan derivative films improved protein adsorption properties compared to chitosan films. The HUVEC cell morphology showed well attachment and spread phenotype on chitosan derivative films compared to those growing on chitosan films which did not spread and remained round. Evaluation of cell viability revealed improvement of cell adhesion on chitosan derivative films compared to chitosan film depending on the quantity of oxidized phenols grafted on chitosan. In addition, FA-/EF-chitosan films allowed almost similar cell adhesion. Furthermore, cell adhesion was increased with the film thickness. These results suggested that the oxidized phenols grafting on chitosan is a promising process to enhance cell adhesion, growth and creating useful functional biomaterials. 相似文献
Phosphatidylcholine liposomes bound to the surface of L cells inhibit cell attachment to L-cell monolayers or to lipid films. Aggregation of L cells or of mouse embryo fibroblasts is also diminished upon treatment with liposomes. However, they neither inhibit cell attachment to glass or cellulose acetate substrata, nor diminish conA-mediated cell aggregation. It is supposed that liposome-binding sites on the cell surface described earlier are involved in cell-cell attachment. 相似文献
Poly-L-lactides containing beta-alkyl alpha-malate-units were prepared by ring-opening copolymerizations of L-lactide with 3-(s)-[(benzyloxycarbonyl)methyl]- (BMD) and 3-(s)-[(dodecyloxycarbonyl)methyl]-1,4-dioxane-2,5-diones (DMD). The solution-cast films of these copolymers were alkali-treated to form a carboxyl-functionalized surface on which cell-binding Arg-Gly-Asp tripeptide (RGD) was immobilized with dicyclohexylcarbodiimide as coupling agent. For the copolymer of L-lactide and BMD the benzyl groups were removed by catalytic hydrogenolysis to obtain a fully carboxyl-functionalized copolymer (PLGM), and RGD was immobilized on the surface of its cast film. All the RGD-immobilized films thus prepared exhibited improved cell attachment compared with the original films. The cell attachment increased with increasing amount of immobilized RGD, which depended on the composition of the alpha-malate units in the copolymer. The RGD-immobilized PLGM films were degraded rapidly during the cell culture, while the RGD-immobilized films of the beta-alkyl alpha-malate-containing polymers survived the cell culture with little degradation. The rate of hydrolysis increased with increasing content of alpha-malate units for both series, depending on the structure of the protecting groups of the beta-carboxyl. These results suggest that the RGD-immobilized polymers could be a new class of functional bioresorbable polymer having improved cell-attachment and adjustable hydrolysis rate. 相似文献
Thin films of TiN were investigated as a candidate microelectrode material for multi-electrode arrays, which are used for recording from electrically active cells in culture. TiN films were deposited onto glass substrates by DC pulsed reactive magnetron sputtering. The structure, phase composition and surface chemistry were studied using X-ray diffraction (XRD), Atomic force microscopy (AFM) and X-ray photoelectron spectroscopy (XPS). The biocompatibility of the TiN films was examined morphologically by monitoring neuronal network formation and comparing this to a control substrate. Results indicate that neuronal cell adhesion and growth is influenced by the surface chemistry and associated crystal orientation of the TiN thin films. 相似文献
The authors expose their observations about the kinetics of cell adesion on two materials used as implants in orthopaedic surgery, AISI, 316 L steel and passivated titanium. The kinetics of cell attachment have been compared: an initial rapid increase of bound radioactivity was observed on passivated titanium (in 5 - 30 min) and after this rapid reaction the number of attached cells increased only slowly, during the following 30 min. After incubation of 90 min, almost all cells became attached. Kinetic of BHK cell attachment on AISI 316 L differs significantly: almost all added cells were attached in 90 min but the rapid increase of attachment is observed only during the first 30 min. These observations are important for the comprension of adhesion mechanisms and characterize the properties of biocompatibility of implant materials. 相似文献
The specific aim of the present study was to investigate the biodegradation and biocompatibility characteristics of rosin,
a natural film-forming polymer. Both in vitro as well as in vivo methods were used for assessment of the same. The in vitro
degradation of rosin films was followed in pH 7.4 phosphate buffered saline at 37°C and in vivo by subdermal implantation
in rats for up to 90 days. Initial biocompatibility was followed on postoperative days 7, 14, 21, and 28 by histological observations
of the surrounding tissues around the implanted films. Poly (DL-lactic-co-glycolic acid) (PLGA) (50∶50) was used as reference
material for biocompatibility. Rate and extent of degradation were followed in terms of dry film weight loss, molecular weight
(MW) decline, and surface morphological changes. Although the rate of in vitro degradation was slow, rosin-free films showed
complete degradation between 60 and 90 days following subdermal implantation in rats. The films degraded following different
rates, in vitro and in vivo, but the mechanism followed was primarily bulk degradation. Rosin films demonstrated inflammatory
reactions similar to PLGA, indicative of good biocompatibility. Good biocompatibility comparable to PLGA is demonstrated by
the absence of necrosis or abscess formation in the surrounding tissues. The study provides valuable insight, which may lead
to new applications of rosin in the field of drug delivery. 相似文献
The features of substrate necessary for cell attachment were studied using different lipid films adsorbed on glass coverslips. Mouse embryo fibroblasts attach and spread on dipalmitoyllecithin, tripalmitin, and sphingomyelin films which were in crystalline (gel) state at 37 °C. The liquid-crystalline films made of total brain lipids, phosphatidylethanolamine, as well as of egg yolk and rat liver lecithins, were non-adhesive for cells. Cholesterol which is known to abolish the gel to liquid-crystalline transition of dipalmitoyllecithin makes it also non-adhesive for the cells. The mechanism of lipid fluid film non-adhesiveness for cell attachment is discussed in relation to cell-cell contact interactions. 相似文献
In the present study, the effect of nanosized graphene oxide layer on thermal stability and biocompatibility of gold nanorods has been examined. The graphene oxide-wrapped gold nanorods were prepared by electrostatic interaction between negatively charged graphene oxide and positively charged nanorods. The resulting nanohybrids were then heated at different time intervals to 95 °C in a water bath to assess the effect of heat on the rods morphology. The structural changes in gold nanorods were monitored via UV-Vis spectroscopy measurements and transmission electron microscopy images. In similar experiments, the graphene oxide used to wrap gold nanorods was reduced by ascorbic acid in a 95 °C water bath. Our results indicate that while bare gold nanorods are highly vulnerable to elevated temperatures, graphene oxide and reduced graphene oxide-coated gold nanorods remain thermally stable with no structural changes. We also confirmed that the enhanced thermal stability is highly dependent on the concentration of deposited graphene oxide available on the surface of the gold nanorods. In addition, we performed an MTT (3-[4,5-dimethylthiazol-2yl]-2,5-diphenyltetrazoliumbromide) assay to make a comparison between the cytotoxicity of the nanohybrids and their primary building blocks on human dermal fibroblast cells as a normal cell line. We found evidence that graphene oxide can enhance the biocompatibility of the rods through covering toxic chemicals on the surface of them.
Bio-composite scaffolds were prepared by freeze-drying using poly(3-hydroxubutyrate-co-4-hydroxubutyrate) (P(3HB-co-4HB)) and bacterial cellulose (BC) as raw materials and trifluoroacetic acid (TFA) as co-solvent. The characteristics of the composite scaffold were investigated by field emission scanning electron microscopy (FESEM), Fourier transform infrared spectra (FT-IR), X-ray diffraction (XRD), water contact angle measurement and tensile testing. Preliminary biodegradation test was performed for P(3HB-co-4HB) and P(3HB-co-4HB)/BC composite scaffold in buffer solution and enzyme solution. The biocompatibility of the composite scaffold was preliminarily evaluated by cell adhesion studies using Chinese Hamster Lung (CHL) fibroblast cells. The cells incubated with composite scaffold for 48 h were capable of forming cell adhesion and proliferation, which showed better biocompatibility than pure P(3HB-co-4HB) scaffold. Thus, the prepared P(3HB-co-4HB)/BC composite scaffold was bioactive and may be suitable for cell adhesion/attachment suggesting that these scaffolds can be used for wound dressing or tissue-engineering scaffolds. 相似文献
The search for naturally occurring nanocomposites with diverse properties for tissue engineering has been a major interest
for biomaterial research. In this study, we investigated a nanofiber and nanoparticle based nanocomposite secreted from an
insect-capturing plant, the Sundew, for cell attachment. The adhesive nanocomposite has demonstrated high biocompatibility
and is ready to be used with minimal preparation. 相似文献