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Sample records for cells up-take cytocompatibility

  1. Investigation of interactions between poly-L-lysine-coated boron nitride nanotubes and C2C12 cells: up-take, cytocompatibility, and differentiation

    Directory of Open Access Journals (Sweden)

    G Ciofani

    2010-04-01

    Full Text Available G Ciofani1, L Ricotti1, S Danti2,3, S Moscato4, C Nesti2, D D’Alessandro2,4, D Dinucci5, F Chiellini5, A Pietrabissa3, M Petrini2,3, A Menciassi1,61Scuola Superiore Sant’Anna, Pisa, Italy; 2CUCCS-RRMR, Center for the Clinical Use of Stem Cells – Regional Network of Regenerative Medicine, 3Department of Oncology, Transplants and Advanced Technologies, 4Department of Human Morphology and Applied Biology, University of Pisa, Pisa, Italy; 5Laboratory of Bioactive Polymeric Materials for Biomedical and Environmental Applications (BIOlab, UdR INSTM, Department of Chemistry and Industrial Chemistry, University of Pisa, San Piero a Grado, Italy; 6Italian Institute of Technology, Genova, ItalyAbstract: Boron nitride nanotubes (BNNTs have generated considerable interest within the scientific community by virtue of their unique physical properties, which can be exploited in the biomedical field. In the present in vitro study, we investigated the interactions of poly-L-lysine-coated BNNTs with C2C12 cells, as a model of muscle cells, in terms of cytocompatibility and BNNT internalization. The latter was performed using both confocal and transmission electron microscopy. Finally, we investigated myoblast differentiation in the presence of BNNTs, evaluating the protein synthesis of differentiating cells, myotube formation, and expression of some constitutive myoblastic markers, such as MyoD and Cx43, by reverse transcription – polymerase chain reaction and Western blot analysis. We demonstrated that BNNTs are highly internalized by C2C12 cells, with neither adversely affecting C2C12 myoblast viability nor significantly interfering with myotube formation.Keywords: boron nitride nanotubes, C2C12 cells, cytocompatibility, up-take, differentiation, MyoD, connexin 43

  2. Investigation of interactions between poly-l-lysine-coated boron nitride nanotubes and C2C12 cells: up-take, cytocompatibility, and differentiation

    Science.gov (United States)

    Ciofani, G; Ricotti, L; Danti, S; Moscato, S; Nesti, C; D’Alessandro, D; Dinucci, D; Chiellini, F; Pietrabissa, A; Petrini, M; Menciassi, A

    2010-01-01

    Boron nitride nanotubes (BNNTs) have generated considerable interest within the scientific community by virtue of their unique physical properties, which can be exploited in the biomedical field. In the present in vitro study, we investigated the interactions of poly-l-lysine-coated BNNTs with C2C12 cells, as a model of muscle cells, in terms of cytocompatibility and BNNT internalization. The latter was performed using both confocal and transmission electron microscopy. Finally, we investigated myoblast differentiation in the presence of BNNTs, evaluating the protein synthesis of differentiating cells, myotube formation, and expression of some constitutive myoblastic markers, such as MyoD and Cx43, by reverse transcription – polymerase chain reaction and Western blot analysis. We demonstrated that BNNTs are highly internalized by C2C12 cells, with neither adversely affecting C2C12 myoblast viability nor significantly interfering with myotube formation. PMID:20463944

  3. Cytocompatibility of Self-assembled Hydrogel from IKVAV-containing Peptide Amphiphile with Neural Stem Cells

    Institute of Scientific and Technical Information of China (English)

    SONG Yulin; ZHENG Qixin; GUO Xiaodong; ZHENG Jianfeng

    2009-01-01

    Neural Stem Cells(NSCs)were incubated with self-assembled hydrogel from IKVAV-containing peptide amphiphile(IKVAV-PA)for one week.The cytocompatibility of hydrogel was evaluated.NSCs were seeded in three-dimensional(3D)hydrogels(Experimental Group,EG)or surface of coverslips(Control Group,CG),double-labeled with Calcein-AM and PI.A growth curve of cells was obtained according to CCK-8.TEM study of hydrogel revealed a network of nanofibers. NSCs began to proliferate after 24 h of incubation,and formed bigger neurospheres at 48 h in EG than in CG.Cell proliferation activity was higher in EG than in CG(P<0.05).The self-assembled Hydrogel had good cytocompatibility and promoted the proliferation of NSCs.

  4. Self-assembled mannan nanogel : cytocompatibility and cell localization

    OpenAIRE

    Ferreira, Sílvia A.; Carvalho, Vera; Vilanova, Manuel; Costa, Carla Isabel; Teixeira, João P.; Gama, F. M.

    2012-01-01

    Amphiphilic mannan, produced by the Michael addition of hydrophobic 1-hexadecanethiol to vinyl methacrylated mannan, self-assembles in aqueous medium through hydrophobic interactions among alkyl chains. Resultant nanogel is stable, spherical, polydisperse, with 50–140 nm mean hydrodynamic diameter depending on the polymer degree of substitution, and nearly neutral negative surface charge. No cytotoxicity of mannan nanogel is detected up to about 0.4 mg/mL in mouse embryo fibroblast cell line ...

  5. A Comparative Study on Root Canal Repair Materials: A Cytocompatibility Assessment in L929 and MG63 Cells

    Directory of Open Access Journals (Sweden)

    Yuqing Jiang

    2014-01-01

    Full Text Available Cytocompatibility of repair materials plays a significant role in the success of root canal repair. We conducted a comparative study on the cytocompatibility among iRoot BP Plus, iRoot FS, ProRoot MTA, and Super-EBA in L929 cells and MG63 cells. The results revealed that iRoot FS was able to completely solidify within 1 hour. iRoot BP Plus required 7-day incubation, which was much longer than expected (2 hours, to completely set. ProRoot MTA and Super-EBA exhibited a similar setting duration of 12 hours. All the materials except Super-EBA possessed negligible in vitro cytotoxicity. iRoot FS had the best cell adhesion capacity in both L929 and MG63 cells. With rapid setting, negligible cytotoxicity, and enhanced cell adhesion capacity, iRoot FS demonstrated great potential in clinical applications. Future work should focus on longer-term in vitro cytocompatibility and an in vivo assessment.

  6. Cytocompatibility of direct water synthesized cadmium selenide quantum dots in colo-205 cells

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez-Torres, Marcos R. [Universidad Metropolitana, Nanomaterials Science Laboratory, School of Science and Technology (United States); Velez, Christian; Zayas, Beatriz [Universidad Metropolitana, ChemTox Laboratory, School of Environmental Affairs (United States); Rivera, Osvaldo [Universidad Metropolitana, Nanomaterials Science Laboratory, School of Science and Technology (United States); Arslan, Zikri [Jackson State University, Department of Chemistry (United States); Gonzalez-Vega, Maxine N. [Universidad Metropolitana, Nanomaterials Science Laboratory, School of Science and Technology (United States); Diaz-Diestra, Daysi; Beltran-Huarac, Juan; Morell, Gerardo [University of Puerto Rico, Molecular Science Research Center (United States); Primera-Pedrozo, Oliva M., E-mail: oprimera1@suagm.edu [Universidad Metropolitana, Nanomaterials Science Laboratory, School of Science and Technology (United States)

    2015-06-15

    Cadmium selenide quantum dots (CdSe QDs), inorganic semiconducting nanocrystals, are alluring increased attraction due to their highly refined chemistry, availability, and super tunable optical properties suitable for many applications in different research areas, such as photovoltaics, light-emitting devices, environmental sciences, and nanomedicine. Specifically, they are being widely used in bio-imaging in contrast to organic dyes due to their high brightness and improved photo-stability, and their ability to tune their absorption and emission spectra upon changing the crystal size. The production of CdSe QDs is mostly assisted by trioctylphosphine oxide compound, which acts as solvent or solubilizing agent and renders the QDs soluble in organic compounds (such as toluene, chloroform, and hexane) that are highly toxic. To circumvent the toxicity-related factor in CdSe QDs, we report the synthesis of CdSe QDs capped with thioglycolic acid (TGA) in an aqueous medium, and their biocompatibility in colo-205 cancer cells. In this study, the [Cd{sup 2+}]/[TGA] ratio was adjusted to 11:1 and the Se concentration (10 and 15 mM) was monitored in order to evaluate its influence on the optical properties and cytocompatibility. QDs resulted to be quite stable in water (after purification) and RPMI cell medium and no precipitation was observed for long contact times, making them appealing for in vitro experiments. The spectroscopy analysis, advanced electron microscopy, and X-ray diffractometry studies indicate that the final products were successfully formed exhibiting an improved optical response. Colo-205 cells being exposed to different concentrations of TGA-capped CdSe QDs for 12, 24, and 48 h with doses ranging from 0.5 to 2.0 mM show high tolerance reaching cell viabilities as high as 93 %. No evidence of cellular apoptotic pathways was observed as pointed out by our Annexin V assays at higher concentrations. Moreover, confocal microscopy analysis conducted to

  7. Cytocompatibility of direct water synthesized cadmium selenide quantum dots in colo-205 cells

    International Nuclear Information System (INIS)

    Cadmium selenide quantum dots (CdSe QDs), inorganic semiconducting nanocrystals, are alluring increased attraction due to their highly refined chemistry, availability, and super tunable optical properties suitable for many applications in different research areas, such as photovoltaics, light-emitting devices, environmental sciences, and nanomedicine. Specifically, they are being widely used in bio-imaging in contrast to organic dyes due to their high brightness and improved photo-stability, and their ability to tune their absorption and emission spectra upon changing the crystal size. The production of CdSe QDs is mostly assisted by trioctylphosphine oxide compound, which acts as solvent or solubilizing agent and renders the QDs soluble in organic compounds (such as toluene, chloroform, and hexane) that are highly toxic. To circumvent the toxicity-related factor in CdSe QDs, we report the synthesis of CdSe QDs capped with thioglycolic acid (TGA) in an aqueous medium, and their biocompatibility in colo-205 cancer cells. In this study, the [Cd2+]/[TGA] ratio was adjusted to 11:1 and the Se concentration (10 and 15 mM) was monitored in order to evaluate its influence on the optical properties and cytocompatibility. QDs resulted to be quite stable in water (after purification) and RPMI cell medium and no precipitation was observed for long contact times, making them appealing for in vitro experiments. The spectroscopy analysis, advanced electron microscopy, and X-ray diffractometry studies indicate that the final products were successfully formed exhibiting an improved optical response. Colo-205 cells being exposed to different concentrations of TGA-capped CdSe QDs for 12, 24, and 48 h with doses ranging from 0.5 to 2.0 mM show high tolerance reaching cell viabilities as high as 93 %. No evidence of cellular apoptotic pathways was observed as pointed out by our Annexin V assays at higher concentrations. Moreover, confocal microscopy analysis conducted to evaluate

  8. Coatings of Different Carbon Nanotubes on Platinum Electrodes for Neuronal Devices: Preparation, Cytocompatibility and Interaction with Spiral Ganglion Cells

    Science.gov (United States)

    Schwarz, Hans-Christoph; Kranz, Katharina; Motz, Damian; Vogt, Carla; Lenarz, Thomas; Warnecke, Athanasia; Behrens, Peter

    2016-01-01

    Cochlear and deep brain implants are prominent examples for neuronal prostheses with clinical relevance. Current research focuses on the improvement of the long-term functionality and the size reduction of neural interface electrodes. A promising approach is the application of carbon nanotubes (CNTs), either as pure electrodes but especially as coating material for electrodes. The interaction of CNTs with neuronal cells has shown promising results in various studies, but these appear to depend on the specific type of neurons as well as on the kind of nanotubes. To evaluate a potential application of carbon nanotube coatings for cochlear electrodes, it is necessary to investigate the cytocompatibility of carbon nanotube coatings on platinum for the specific type of neuron in the inner ear, namely spiral ganglion neurons. In this study we have combined the chemical processing of as-delivered CNTs, the fabrication of coatings on platinum, and the characterization of the electrical properties of the coatings as well as a general cytocompatibility testing and the first cell culture investigations of CNTs with spiral ganglion neurons. By applying a modification process to three different as-received CNTs via a reflux treatment with nitric acid, long-term stable aqueous CNT dispersions free of dispersing agents were obtained. These were used to coat platinum substrates by an automated spray-coating process. These coatings enhance the electrical properties of platinum electrodes, decreasing the impedance values and raising the capacitances. Cell culture investigations of the different CNT coatings on platinum with NIH3T3 fibroblasts attest an overall good cytocompatibility of these coatings. For spiral ganglion neurons, this can also be observed but a desired positive effect of the CNTs on the neurons is absent. Furthermore, we found that the well-established DAPI staining assay does not function on the coatings prepared from single-wall nanotubes. PMID:27385031

  9. Cytocompatibility property evaluation of gas pressure sintered SiAlON–SiC composites with L929 fibroblast cells and Saos-2 osteoblast-like cells

    International Nuclear Information System (INIS)

    Although the oxide ceramics have widely been investigated for their biocompatibility, non-oxide ceramics, such as SiAlON and SiC are yet to be explored in detail. Lack of understanding of the biocompatibility restricts the use of these ceramics in clinical trials. It is hence, essential to carry out proper and thorough study to assess cell adhesion, cytocompatibility and cell viability on the non-oxide ceramics for the potential applications. In this perspective, the present research work reports the cytocompatibility of gas pressure sintered SiAlON monolith and SiAlON–SiC composites with varying amount of SiC, using connective tissue cells (L929) and bone cells (Saos-2). The quantification of cell viability using MTT assay reveals the non-cytotoxic response. The cell viability has been found to be cell type dependent. An attempt has been made to discuss the cytocompatibility of the developed composites in the light of SiC content and type of sinter additives. - Highlights: ► SiAlON and SiAlON–SiC composite can be used as substrate for the proliferation of L929 mouse fibroblast and Saos-2 osteoblast-like cells. ► Addition of SiC to SiAlON matrix does not degrade cytocompatibility property. ► The cell viability of the SiAlON–SiC is found to be cell type dependent. ► The use of Yb–Sm–Ca as sinter-aid appears to degrade cell viability of L929 cells.

  10. Nanocomposites of high-density polyethylene with amorphous calcium phosphate: in vitro biomineralization and cytocompatibility of human mesenchymal stem cells

    International Nuclear Information System (INIS)

    Polyethylene is widely used as a component of implants in medicine. Composites made of high-density polyethylene (HDPE) containing different amounts of amorphous calcium phosphate nanoparticles were investigated concerning their in vitro biomedical performance. The nanoparticles were produced by flame spray synthesis and extruded with HDPE, the latter complying with Food and Drug Administration regulations. Mechanical properties such as Young's modulus and contact angle as well as in vitro biomineralization of the nanocomposites hot-pressed into thin films were evaluated. The deposition of a hydroxyapatite layer occurred upon immersion in simulated body fluid. Additionally, a cell culture study with human mesenchymal stem cells for six weeks allowed a primary assessment of the cytocompatibility. Viability assays (alamarBlue and lactate dehydrogenase detection) proved the absence of cytotoxic effects of the scaffolds. Microscopic images after hematoxylin and eosin staining confirmed typical growth and morphology. A preliminary experiment analyzed the alkaline phosphatase activity after two weeks. These findings motivate further investigations on bioactive HDPE in bone tissue engineering. (paper)

  11. Cytocompatibility Evaluation of Grafted IKVAV PLEOF Hydrogels with Bone Marrow Mesenchymal Stem Cells

    Institute of Scientific and Technical Information of China (English)

    LI Binbin; ZHANG Ping; YIN Yixia; QIU Tong; TAO Yuan; WANG Xinyu; LI Shipu

    2014-01-01

    The novel hydrogels-grafted IKVAV poly (lactide-co-ethylene oxide-co-fumarate) (PLEOF) hydrogels (GIPHs) were developed. The rat bone marrow mesenchymal stem cells (BMMSCs) were employed, and the cell vitality and apoptosis assays were carried out to evaluate the cytocomptibility of GIPHs. Our data demonstrated that the influence of GIPHs on the proliferation of BMMSCs was in a concentration and time dependent manner. The proliferative ability of BMMSCs in GIPHs-treated group (100μg/mL) after 72 h presented a maximum response which was 30.1%more than that of control group. The numbers of apoptotic cells in GIPHs-treated group (100μg/mL) were just as much as that of control group after 24 h treatment. The GIPHs are able to provide an appropriate environment for BMMSCs survival and proliferation.

  12. Highly cytocompatible and flexible three-dimensional graphene/polydimethylsiloxane composite for culture and electrochemical detection of L929 fibroblast cells.

    Science.gov (United States)

    Waiwijit, Uraiwan; Maturos, Thitima; Pakapongpan, Saithip; Phokharatkul, Ditsayut; Wisitsoraat, Anurat; Tuantranont, Adisorn

    2016-08-01

    Recently, three-dimensional graphene interconnected network has attracted great interest as a scaffold structure for tissue engineering due to its high biocompatibility, high electrical conductivity, high specific surface area and high porosity. However, free-standing three-dimensional graphene exhibits poor flexibility and stability due to ease of disintegration during processing. In this work, three-dimensional graphene is composited with polydimethylsiloxane to improve the structural flexibility and stability by a new simple two-step process comprising dip coating of polydimethylsiloxane on chemical vapor deposited graphene/Ni foam and wet etching of nickel foam. Structural characterizations confirmed an interconnected three-dimensional multi-layer graphene structure with thin polydimethylsiloxane scaffold. The composite was employed as a substrate for culture of L929 fibroblast cells and its cytocompatibility was evaluated by cell viability (Alamar blue assay), reactive oxygen species production and vinculin immunofluorescence imaging. The result revealed that cell viability on three-dimensional graphene/polydimethylsiloxane composite increased with increasing culture time and was slightly different from a polystyrene substrate (control). Moreover, cells cultured on three-dimensional graphene/polydimethylsiloxane composite generated less ROS than the control at culture times of 3-6 h. The results of immunofluorescence staining demonstrated that fibroblast cells expressed adhesion protein (vinculin) and adhered well on three-dimensional graphene/polydimethylsiloxane surface. Good cell adhesion could be attributed to suitable surface properties of three-dimensional graphene/polydimethylsiloxane with moderate contact angle and small negative zeta potential in culture solution. The results of electrochemical study by cyclic voltammetry showed that an oxidation current signal with no apparent peak was induced by fibroblast cells and the oxidation current at an

  13. Influence of biodegradable polymer coatings on corrosion, cytocompatibility and cell functionality of Mg-2.0Zn-0.98Mn magnesium alloy.

    Science.gov (United States)

    Witecka, Agnieszka; Yamamoto, Akiko; Idaszek, Joanna; Chlanda, Adrian; Święszkowski, Wojciech

    2016-08-01

    Four kinds of biodegradable polymers were employed to prepare bioresorbable coatings on Mg-2.0Zn-0.98Mn (ZM21) alloy to understand the relationship between polymer characteristics, protective effects on substrate corrosion, cytocompatibility and cell functionality. Poly-l-lactide (PLLA), poly(3-hydroxybutyrate) (PHB), poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) or poly(lactic-co-glycolic) acid (PLGA) was spin-coated on ZM21, obtaining a smooth, non-porous coating less than 0.5μm in thickness. Polymer coating characterization, a degradation study, and biocompatibility evaluations were performed. After 4 w of immersion into cell culture medium, degradation of PLGA and PLLA coatings were confirmed by ATR-FTIR observation. The coatings of PLLA, PHB and PHBV, which have lower water permeability and slower degradation than PLGA, provide better suppression of initial ZM21 degradation and faster promotion of human osteosarcoma cell growth and differentiation. PMID:27100855

  14. Immobilization of biomacromolecules on poly-L-lactide surface via a layer-by-layer method for the improving of its cytocompatibility to bone marrow stromal cells

    Institute of Scientific and Technical Information of China (English)

    L(U) Delong; MENG Sheng; ZHONG Wei; DU Qiangguo; GONG Li; LIU Jinfen; Dusan Bakos

    2005-01-01

    Hyaluronic acid (HA) and chitosan (CS) were immobilized on the surface of poly-L-lactide (PLLA) by the following procedure: Firstly, PLLA was aminolyzed with 1, 6-hexanediamine, and part of the PLLA surface ester groups were converted to free amino groups. Then negatively charged hyaluronic acid and positively charged chitosan were deposited onto the surface of aminolyzed PLLA film in a layer-by-layer assembly manner. The effect of the layer-by- layer deposition was evaluated by ATR-FTIR spectroscopy, Raman spectroscopy and static contact angle measurements. The cytocompatibility of PLLA sample to bone marrow stromal cells (BMSCs) was improved after modification with chitosan and HA. The cell attachment, activity, and proliferation on CS/HA modified PLLA films were enhanced comparing with the control. The cells cultured on the modified PLLA samples excreted abundant cytoplasm and can differentiate to vascular smooth muscle (SM)-like (SM-like) cells. A macroporous three-dimensional PLLA scaffold was prepared by integrating both the technique of freeze-drying and particle leaching. Layer-by-layer modification by HA/CS and cell culture was also applied on this scaffold. The scaffold cultured with BMSCs for 2 weeks has been tested successfully in vivo as a patch for repairing the artificial incision on canine pulmonary artery.

  15. Cytocompatibility and response of osteoblastic-like cells to starch-based polymers: effect of several additives and processing conditions.

    Science.gov (United States)

    Gomes, M E; Reis, R L; Cunha, A M; Blitterswijk, C A; de Bruijn, J D

    2001-07-01

    This work reports on the biocompatibility evaluation of new biodegradable starch-based polymers that are under consideration for use in orthopaedic temporary applications and as tissue engineering scaffolds. It has been shown in previous works that by using these polymers it is both possible to produce polymer/hydroxyapatite (HA) composites (with or without the use of coupling agents) with mechanical properties matching those of the human bone, and to obtain 3D structures generated by solid blowing agents, that are suitable for tissue engineering applications. This study was focused on establishing the influence of several additives (ceramic fillers, blowing agents and coupling agents) and processing methods/conditions on the biocompatibility of the materials described above. The cytotoxicity of the materials was evaluated using cell culture methods, according to ISO/EN 109935 guidelines. A cell suspension of human osteosarcoma cells (HOS) was also seeded on a blend of corn starch with ethylene vinyl alcohol (SEVA-C) and on SEVA-C/HA composites, in order to have a preliminary indication on cell adhesion and proliferation on the materials surface. In general, the obtained results show that all the different materials based on SEVA-C, (which are being investigated for use in several biomedical applications), as well as all the additives (including the novel coupling agents) and different processing methods required to obtain the different properties/products, can be used without inducing a cytotoxic behaviour to the developed biomaterials. PMID:11396897

  16. The Preparation and Cytocompatibility of Injectable Thermosensitive Chitosan/Poly(vinyl alcohol) Hydrogel

    Institute of Scientific and Technical Information of China (English)

    漆白文; 喻爱喜; 祝少博; 陈彪; 李艳

    2010-01-01

    In order to investigate the strength,structure and cell cytocompatibility of injectable thermosensitive chitosan(CS)/poly(vinyl alcohol)(PVA)composite hydrogel,chitosan hydrochloride solution was transferred to a neutral pH and mixed with different proportions of PVA,then the gelation time and strength of these different hydrogels were tested and spatial structures were observed under a scanning electron microscopy(SEM)after freeze-drying.The cytocompatibility of the hydrogels was evaluated through cytotoxi...

  17. Hierarchical structure and cytocompatibility of fish scales from Carassius auratus

    International Nuclear Information System (INIS)

    To study the structure and the cytocompatibility of fish scales from Carassius auratus, scanning electron microscopy (SEM) was used to observe the morphology of fish scales treated with different processing methods. Based on varying morphologies and components, the fish scales can be divided into three regions on the surface and three layers in vertical. The functions of these three individual layers were analyzed. SEM results show that the primary inorganic components are spherical or cubic hydroxyapatite (HA) nanoparticles. The fish scales have an ∼ 60° overlapped plywood structure of lamellas in the fibrillary plate. The plywood structure consists of co-aligned type I collagen fibers, which are parallel to the HA lamellas. X-ray diffraction (XRD), thermogravimetric analysis/differential scanning calorimetry (TGA/DSC) and Fourier transform infrared (FTIR) analysis indicate that the main components are HA and type I collagen fibers. MC3T3-E1 cell culture results show a high cytocompatibility and the ability to guide cell proliferation and migration along the scale ridge channels of the fish scales. This plywood structure provides inspiration for a structure-enhanced composite material. - Highlights: • The Carassius auratus fish scale can be divided into 3 layers rather than 2. • The functions of these three individual layers were firstly analyzed. • The fish scale shows a high cytocompatibility. • The fish scale can guide cells migration along the scale ridge channels

  18. Hierarchical structure and cytocompatibility of fish scales from Carassius auratus

    Energy Technology Data Exchange (ETDEWEB)

    Fang, Zhou [State Key Laboratory of New Ceramics and Fine Processing, School of Materials Science and Engineering, Tsinghua University, Beijing 100084 (China); Wang, Yukun [State Key Laboratory of Geological Processes and Mineral Resources, China University of Geosciences, Beijing 100084 (China); Feng, Qingling, E-mail: biomater@mail.tsinghua.edu.cn [State Key Laboratory of New Ceramics and Fine Processing, School of Materials Science and Engineering, Tsinghua University, Beijing 100084 (China); Key Laboratory of Advanced Materials of Ministry of Education of China, School of Materials Science and Engineering, Tsinghua University, Beijing 100084 (China); Kienzle, Arne; Müller, Werner E.G. [Institut für Physiologische Chemie, Abteilung Angewandte Molekularbiologie, Johannes Gutenberg-Universität, Duesbergweg 6, Mainz 55099 (Germany)

    2014-10-01

    To study the structure and the cytocompatibility of fish scales from Carassius auratus, scanning electron microscopy (SEM) was used to observe the morphology of fish scales treated with different processing methods. Based on varying morphologies and components, the fish scales can be divided into three regions on the surface and three layers in vertical. The functions of these three individual layers were analyzed. SEM results show that the primary inorganic components are spherical or cubic hydroxyapatite (HA) nanoparticles. The fish scales have an ∼ 60° overlapped plywood structure of lamellas in the fibrillary plate. The plywood structure consists of co-aligned type I collagen fibers, which are parallel to the HA lamellas. X-ray diffraction (XRD), thermogravimetric analysis/differential scanning calorimetry (TGA/DSC) and Fourier transform infrared (FTIR) analysis indicate that the main components are HA and type I collagen fibers. MC3T3-E1 cell culture results show a high cytocompatibility and the ability to guide cell proliferation and migration along the scale ridge channels of the fish scales. This plywood structure provides inspiration for a structure-enhanced composite material. - Highlights: • The Carassius auratus fish scale can be divided into 3 layers rather than 2. • The functions of these three individual layers were firstly analyzed. • The fish scale shows a high cytocompatibility. • The fish scale can guide cells migration along the scale ridge channels.

  19. Cytocompatibility of a silk fibroin tubular scaffold

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Jiannan, E-mail: wangjn@suda.edu.cn; Wei, Yali; Yi, Honggen; Liu, Zhiwu; Sun, Dan; Zhao, Huanrong

    2014-01-01

    Regenerated silk fibroin (SF) materials are increasingly used for tissue engineering applications. In order to explore the feasibility of a novel biomimetic silk fibroin tubular scaffold (SFTS) crosslinked by poly(ethylene glycol) diglycidyl ether (PEG-DE), biocompatibility with cells was evaluated. The novel biomimetic design of the SFTS consisted of three distinct layers: a regenerated SF intima, a silk braided media and a regenerated SF adventitia. The SFTS exhibited even silk fibroin penetration throughout the braid, forming a porous layered tube with superior mechanical, permeable and cell adhesion properties that are beneficial to vascular regeneration. Cytotoxicity and cell compatibility were tested on L929 cells and human umbilical vein endothelial cells (EA.hy926). DNA content analysis, scanning electron and confocal microscopies and MTT assay showed no inhibitory effects on DNA replication. Cell morphology, viability and proliferation were good for L929 cells, and satisfactory for EA.hy926 cells. Furthermore, the suture retention strength of the SFTS was about 23 N and the Young's modulus was 0.2–0.3 MPa. Collectively, these data demonstrate that PEG-DE crosslinked SFTS possesses the appropriate cytocompatibility and mechanical properties for use as vascular scaffolds as an alternative to vascular autografts. - Highlights: • A PEG-DE cross-linked small caliber porous silk fibroin tubular scaffold (SFTS) • PEG-DE cross-linked SF film had no inhibitory effect on DNA replication of cells. • Cells cultured on the SFTS showed good morphology, cell viability and proliferative activity. • SFTS would be beneficial to endothelialization. • SFTS had good suture retention strength and flexibility.

  20. Cytocompatible cellulose hydrogels containing trace lignin.

    Science.gov (United States)

    Nakasone, Kazuki; Kobayashi, Takaomi

    2016-07-01

    Sugarcane bagasse was used as a cellulose resource to prepare transparent and flexible cellulose hydrogel films. On the purification process from bagasse to cellulose, the effect of lignin residues in the cellulose was examined for the properties and cytocompatibility of the resultant hydrogel films. The cellulose was dissolved in lithium chloride/N,N-dimethylacetamide solution and converted to hydrogel films by phase inversion. In the purification process, sodium hydroxide (NaOH) treatment time was changed from 1 to 12h. This resulted in cellulose hydrogel films having small amounts of lignin from 1.62 to 0.68%. The remaining lignin greatly affected hydrogel properties. Water content of the hydrogel films was increased from 1153 to 1525% with a decrease of lignin content. Moreover, lower lignin content caused weakening of tensile strength from 0.80 to 0.43N/mm(2) and elongation from 45.2 to 26.5%. Also, similar tendency was observed in viscoelastic behavior of the cellulose hydrogel films. Evidence was shown that the lignin residue was effective for the high strength of the hydrogel films. In addition, scanning probe microscopy in the morphological observation was suggested that the trace lignin in the cellulose hydrogel affected the cellulose fiber aggregation in the hydrogel network. The trace of lignin in the hydrogels also influenced fibroblast cell culture on the hydrogel films. The hydrogel film containing 1.68% lignin showed better fibroblast compatibility as compared to cell culture polystyrene dish used as reference. PMID:27127053

  1. Surface characterization and cytocompatibility evaluation of silanized magnesium alloy AZ91 for biomedical applications

    Directory of Open Access Journals (Sweden)

    Agnieszka Witecka, Akiko Yamamoto, Henryk Dybiec and Wojciech Swieszkowski

    2012-01-01

    Full Text Available Mg alloys with high Al contents have superior corrosion resistance in aqueous environments, but poor cytocompatibility compared to that of pure Mg. We have silanized the cast AZ91 alloy to improve its cytocompatibility using five different silanes: ethyltriethoxysilane (S1, 3-aminopropyltriethoxysilane (S2, 3-isocyanatopyltriethoxysilane (S3, phenyltriethoxysilane (S4 and octadecyltriethoxysilane (S5. The surface hydrophilicity/hydrophobicity was evaluated by water contact angle measurements. X-ray photoelectron analysis was performed to investigate the changes in surface states and chemical composition. All silane reagents increased adsorption of the albumin to the modified surface. In vitro cytocompatibility evaluation revealed that silanization improved cell growth on AZ91 modified by silane S1. Measurement of the concentration of Mg2+ ions released during the cell culture indicated that silanization does not affect substrate degradation.

  2. Cytocompatibility of bio-inspired silicon carbide ceramics.

    Science.gov (United States)

    López-Alvarez, M; de Carlos, A; González, P; Serra, J; León, B

    2010-10-01

    Due to its good mechanical and biochemical properties and, also, because of its unique interconnected porosity, bio-inspired silicon carbide (bioSiC) can be considered as a promising material for biomedical applications, including controlled drug delivery devices and tissue engineering scaffolds. This innovative material is produced by molten-Si infiltration of carbon templates, obtained by controlled pyrolysis of vegetable precursors. The final SiC ceramic presents a porous-interconnected microstructure that mimics the natural hierarchical structure of bone tissue and allows the internal growth of tissue, as well as favors angiogenesis. In the present work, the in vitro cytocompatibility of the bio-inspired SiC ceramics obtained, in this case, from the tree sapelli (Entandrophragma cylindricum) was evaluated. The attachment, spreading, cytoskeleton organization, proliferation, and mineralization of the preosteoblastic cell line MC3T3-E1 were analyzed for up to 28 days of incubation by scanning electron microscopy, interferometric profilometry, confocal laser scanning microscopy, MTT assay, as well as red alizarin staining and quantification. Cells seeded onto these ceramics were able to attach, spread, and proliferate properly with the maintenance of the typical preosteoblastic morphology throughout the time of culture. A certain level of mineralization on the surface of the sapelli-based SiC ceramics is observed. These results demonstrated the cytocompatibility of this porous and hierarchical material. PMID:20737554

  3. Hierarchical structure and cytocompatibility of fish scales from Carassius auratus.

    Science.gov (United States)

    Fang, Zhou; Wang, Yukun; Feng, Qingling; Kienzle, Arne; Müller, Werner E G

    2014-10-01

    To study the structure and the cytocompatibility of fish scales from Carassius auratus, scanning electron microscopy (SEM) was used to observe the morphology of fish scales treated with different processing methods. Based on varying morphologies and components, the fish scales can be divided into three regions on the surface and three layers in vertical. The functions of these three individual layers were analyzed. SEM results show that the primary inorganic components are spherical or cubic hydroxyapatite (HA) nanoparticles. The fish scales have an ~60° overlapped plywood structure of lamellas in the fibrillary plate. The plywood structure consists of co-aligned type I collagen fibers, which are parallel to the HA lamellas. X-ray diffraction (XRD), thermogravimetric analysis/differential scanning calorimetry (TGA/DSC) and Fourier transform infrared (FTIR) analysis indicate that the main components are HA and type I collagen fibers. MC3T3-E1 cell culture results show a high cytocompatibility and the ability to guide cell proliferation and migration along the scale ridge channels of the fish scales. This plywood structure provides inspiration for a structure-enhanced composite material. PMID:25175199

  4. Cure Behaviors and Water Up-take Evaluation of a New Waterborne Epoxy Resin

    Institute of Scientific and Technical Information of China (English)

    WAN Tao; ZANG Tianshun; ZHANG Rui; SUN Xianchang

    2012-01-01

    Cure behaviors and water up-take evaluation of a low cost,ecofriendly and water soluble epoxy resin prepared by reaction between epichlorohydrin and PEG400,PEG600 and PEG1000,respectively,were investigated using non-isothermal differential scanning calorimetry (DSC) and gravimetrical method,respectively.Factors affecting the cure behaviors as well as water up-take of waterborne epoxy resins,such as amount of triethylenetetramine (TETA) and triethylene diamine (TEDA),PEG molecular weight,curing temperature,were systematically investigated.The prepared water soluble epoxy resins can be cured under room temperature with the shape of the curing curves similar to that expected for an autocatalytic reaction.

  5. Selective processes for bioaccumulative up-take of persistent organic pollutants (POPs) in Arctic food webs

    OpenAIRE

    Carlsson, Pernilla Marianne

    2013-01-01

    The overall aim of the present study was to elucidate selective environmental up-take processes in Arctic food webs that lead to the bioaccumulation of persistent organic pollutants (POP) in food items consumed by Arctic indigenous people. In addition, this study aimed to increase the scientific understanding of the principles behind climate change related influences on transport processes of contaminants. Svalbard and Nuuk, Greenland were chosen as study areas since they represent Arctic con...

  6. Antimicrobial Properties and Cytocompatibility of PLGA/Ag Nanocomposites

    Directory of Open Access Journals (Sweden)

    Mariangela Scavone

    2016-01-01

    Full Text Available The purpose of this study was to investigate the antimicrobial properties of multifunctional nanocomposites based on poly(dl-Lactide-co-Glycolide (PLGA and increasing concentration of silver (Ag nanoparticles and their effects on cell viability for biomedical applications. PLGA nanocomposite films, produced by solvent casting with 1 wt%, 3 wt% and 7 wt% of Ag nanoparticles were investigated and surface properties were characterized by atomic force microscopy and contact angle measurements. Antibacterial tests were performed using an Escherichia coli RB and Staphylococcus aureus 8325-4 strains. The cell viability and morphology were performed with a murine fibroblast cell line (L929 and a human osteosarcoma cell line (SAOS-2 by cell viability assay and electron microscopy observations. Matrix protein secretion and deposition were also quantified by enzyme-linked immunosorbent assay (ELISA. The results suggest that the PLGA film morphology can be modified introducing a small percentage of silver nanoparticles, which induce the onset of porous round-like microstructures and also affect the wettability. The PLGA/Ag films having silver nanoparticles of more than 3 wt% showed antibacterial effects against E. coli and S. aureus. Furthermore, silver-containing PLGA films displayed also a good cytocompatibility when assayed with L929 and SAOS-2 cells; indicating the PLGA/3Ag nanocomposite film as a promising candidate for tissue engineering applications.

  7. ADSCs on PLLA/PCL Hybrid Nanoscaffold and Gelatin Modification: Cytocompatibility and Mechanical Properties

    OpenAIRE

    Mashhadikhan, Maedeh; Soleimani, Masoud; Parivar, Kazem; Yaghmaei, Parichehr

    2015-01-01

    Background Development of tissue engineering and regenerative medicine has led to designing scaffolds and their modification to provide a better microenvironment which mimics the natural niche of the cells. Gelatin surface modification was applied to improve scaffold flexibility and cytocompatibility. Methods PLLA/PCL aligned fibrous scaffold was fabricated using electrospinning method. ADSCs were seeded after O2 plasma treatment and gelatin coating of the scaffolds. The morphological and mec...

  8. In vitro bioactivity and cytocompatibility of tricalcium silicate

    Indian Academy of Sciences (India)

    Xiaoming Liao; Hongyang Zhu; Guangfu Yin; Zhongbing Huang; Yadong Yao; Xianchun Chen

    2011-08-01

    The in vitro bioactivity of tricalcium silicate (Ca3SiO5) ceramics was investigated by the bone-like apatite-formation ability in simulated body fluid (SBF), and the cytocompatibility was evaluated through osteoblast adhesion and proliferation assay. The results show that the Ca3SiO5 ceramics possess bone-like apatite formation ability in SBF. In vitro cytocompatible evaluation reveals that osteoblasts adhere and spread well on the Ca3SiO5 ceramics, indicating good bioactivity and cytocompatibility.

  9. Enhanced cytocompatibility of silver-containing biointerface by constructing nitrogen functionalities

    International Nuclear Information System (INIS)

    Graphical abstract: Constructing nitrogen functionalities is promising method to enhance cytocompatibility of the biointerface by simultaneous Ag and N2 plasma modification. - Highlights: • N2 plasma immersion ion implantation (PIII) treatment generates plenty of nitrogen functionalities on polymer substrate. • N2 PIII treatment increases surface roughness and hydrophilicity and improves its capability to adsorb protein. • Simultaneous Ag and N2 plasma modification constructs nitrogen functionalities to enhance cytocompatibility of the biointerface. - Abstract: Silver (Ag) has recently been introduced into polymeric biomedical implants by plasma immersion ion implantation (PIII) to enhance the antibacterial capability. However, Ag ions and nanoparticles can increase the cytotoxicity and inhibit cellular proliferation and the relationship is time- and dose-dependent. In this study, Ag and N2 PIII is conducted in concert to produce nitrogen functional groups as well as Ag-containing biointerface. In addition to the creation of nitrogen functionalities, the surface roughness and hydrophilicity are improved in favor of protein adsorption. Compared to the biointerface created by Ag PIII only, the nitrogen functionalities generated by N2 co-PIII do not affect DNA synthesis and the total protein level but evidently enhance cellular adhesion, viability, and proliferation at the biointerface. The modified surface is observed to upregulate the osteogenesis-related marker expression of bone cells in contact. Our findings suggest that dual Ag and N2 PIII is a desirable technique to enhance both the cytocompatibility and antibacterial capability of medical polymers

  10. Cytocompatibility, cytotoxicity and genotoxicity analysis of dental implants

    International Nuclear Information System (INIS)

    Several types of materials are frequently used for dental prostheses in dental medicine. Different treatments with titanium are the most used. The aim of the present study was to analyze by means of cytotoxicity and cytocompatibility techniques the capacity of dental implants to integrate to the bone tissue. Cultures of UMR 106 cell line derived from an osteosarcoma were used for bioassays mainly because they show many of the properties of osteoblasts. Dental implant samples provided by B and W company were compared with others of recognized trademarks. The first ones contain ASTM titanium (8348 GR2) with acid printing. Cytotoxicity was analyzed by means of lysosome activity, using the neutral red technique and alkaline phosphatase enzyme activity. Cell variability was determined by means of the acridine ethidium-orange bromide technique. One-way ANOVA and Bonferroni and Duncan post-ANOVA tests were used for the statistical analysis. The assays did not show significant differences among the dental implants analyzed. Our findings show that the dental prostheses studied present high biocompatibility, quantified by the bioassays performed. The techniques employed revealed that they can be a useful tool for the analysis of other materials for dental medicine use

  11. Characterization and cytocompatibility of surface modified polyamide66.

    Science.gov (United States)

    Shen, Juan; Li, Yubao; Zuo, Yi; Zou, Qin; Li, Jidong; Huang, Di; Wang, Xiaoyan

    2009-11-01

    The chemical modification of polyamide66 (PA66) membrane by graft polymerization with methacrylic acid (MAA) was initiated under ultraviolet light. Subsequently, covalent immobilization of bioactive surface was obtained by coupling gelatin to the MAA graft chains with the aid of a water-soluble carbodiimide (WSC). The existence of carboxyl groups grafted on PA66 surface was verified quantitatively by UV-vis spectroscopy. The chemical composition, surface topography, and wettability were investigated by Fourier transform infrared (FTIR) technique, X-ray photoelectron spectroscopy, atomic force microscopy, and water contact angle (WCA) measurement. Results showed that the WCA changed from the original value of 67.5 degrees to the minimum value of 30 degrees after grafting with PMAA. Original PA66 displayed a smooth surface morphology [root mean square (RMS) roughness was around 16 nm]. The modified PA66 surface exhibited an increase in roughness (RMS roughness around 21 nm). Simultaneously, the original and modified PA66 membranes were cultured with MG63 cells to investigate their cytocompatibility. The in vitro biological evaluation demonstrated that the immobilization of gelatin on PA66 membrane acted as a good template for the attachment and proliferation of cells. Also, the less toxic reagents and the moderate reaction conditions involved will be very helpful for the introduction of functional groups onto polymer surface. PMID:19637374

  12. Cytocompatibility, cytotoxicity and genotoxicity analysis of dental implants

    Science.gov (United States)

    Reigosa, M.; Labarta, V.; Molinari, G.; Bernales, D.

    2007-11-01

    Several types of materials are frequently used for dental prostheses in dental medicine. Different treatments with titanium are the most used. The aim of the present study was to analyze by means of cytotoxicity and cytocompatibility techniques the capacity of dental implants to integrate to the bone tissue. Cultures of UMR 106 cell line derived from an osteosarcoma were used for bioassays mainly because they show many of the properties of osteoblasts. Dental implant samples provided by B&W company were compared with others of recognized trademarks. The first ones contain ASTM titanium (8348 GR2) with acid printing. Cytotoxicity was analyzed by means of lysosome activity, using the neutral red technique and alkaline phosphatase enzyme activity. Cell variability was determined by means of the acridine ethidium-orange bromide technique. One-way ANOVA and Bonferroni and Duncan post-ANOVA tests were used for the statistical analysis. The assays did not show significant differences among the dental implants analyzed. Our findings show that the dental prostheses studied present high biocompatibility, quantified by the bioassays performed. The techniques employed revealed that they can be a useful tool for the analysis of other materials for dental medicine use.

  13. Cytocompatibility, cytotoxicity and genotoxicity analysis of dental implants

    Energy Technology Data Exchange (ETDEWEB)

    M, Reigosa [Instituto Multidisciplinario de BiologIa Celular (IMBICE) CONICET-CIC.C.C. 403 (1900) La Plata. (Argentina); V, Labarta [Instituto Multidisciplinario de BiologIa Celular (IMBICE) CONICET-CIC.C.C. 403 (1900) La Plata. (Argentina); G, Molinari [Catedra de CitologIa.Facultad de Ciencias Naturales y Museo.UNLP (Argentina); D, Bernales

    2007-11-15

    Several types of materials are frequently used for dental prostheses in dental medicine. Different treatments with titanium are the most used. The aim of the present study was to analyze by means of cytotoxicity and cytocompatibility techniques the capacity of dental implants to integrate to the bone tissue. Cultures of UMR 106 cell line derived from an osteosarcoma were used for bioassays mainly because they show many of the properties of osteoblasts. Dental implant samples provided by B and W company were compared with others of recognized trademarks. The first ones contain ASTM titanium (8348 GR2) with acid printing. Cytotoxicity was analyzed by means of lysosome activity, using the neutral red technique and alkaline phosphatase enzyme activity. Cell variability was determined by means of the acridine ethidium-orange bromide technique. One-way ANOVA and Bonferroni and Duncan post-ANOVA tests were used for the statistical analysis. The assays did not show significant differences among the dental implants analyzed. Our findings show that the dental prostheses studied present high biocompatibility, quantified by the bioassays performed. The techniques employed revealed that they can be a useful tool for the analysis of other materials for dental medicine use.

  14. Fabrication and Cytocompatibility of In Situ Crosslinked Carbon Nanomaterial Films

    Science.gov (United States)

    Patel, Sunny C.; Lalwani, Gaurav; Grover, Kartikey; Qin, Yi-Xian; Sitharaman, Balaji

    2015-05-01

    Assembly of carbon nanomaterials into two-dimensional (2D) coatings and films that harness their unique physiochemical properties may lead to high impact energy capture/storage, sensors, and biomedical applications. For potential biomedical applications, the suitability of current techniques such as chemical vapor deposition, spray and dip coating, and vacuum filtration, employed to fabricate macroscopic 2D all carbon coatings or films still requires thorough examination. Each of these methods presents challenges with regards to scalability, suitability for a large variety of substrates, mechanical stability of coatings or films, or biocompatibility. Herein we report a coating process that allow for rapid, in situ chemical crosslinking of multi-walled carbon nanotubes (MWCNTs) into macroscopic all carbon coatings. The resultant coatings were found to be continuous, electrically conductive, significantly more robust, and cytocompatible to human adipose derived stem cells. The results lay groundwork for 3D layer-on-layer nanomaterial assemblies (including various forms of graphene) and also opens avenues to further explore the potential of MWCNT films as a novel class of nano-fibrous mats for tissue engineering and regenerative medicine.

  15. Cytocompatibility between novel nerve conduit composite materials and bone marrow mesenchymal stem cells%新型神经导管复合材料与骨髓间充质干细胞的相容性*★

    Institute of Scientific and Technical Information of China (English)

    胡辉; 张伟才; 黄继锋; 严琼娇; 殷义霞; 李世普

    2013-01-01

      结果与结论:MTT检测结果显示,共培养5,7 d,实验组吸光度值高于对照组(P OBJECTIVE:To evaluate the cytocompatibility of rat bone marrow mesenchymal stem cel s with (glycolic acid-L-lysine-lactic acid)/poly lactic acid/β-tricalcium phosphate/nerve growth factor composites. METHODS:Passage 3 bone marrow mesenchymal stem cel s which were isolated from Sprague-Dawley rats were co-cultured with (glycolic acid-L-lysine-lactic acid)/poly lactic acid/β-tricalcium phosphate/nerve growth factor composite materials or their extracts, serving as experimental control. Another bone marrow mesenchymal stem cel s cultured in the culture medium containing 10%fetal bovine serum served as controls. Cel growth, survival and apoptosis on the composite materials were observed. RESULTS AND CONCLUSION:Results from 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay showed that absorbance values in the experimental group were higher than those in the control group after co-culture for days 5 and 7 (P<0.05). Annexin V-FITC/PI double staining results showed that the apoptosis rate of the experimental group was significantly lower than that of the control group (P<0.05). Under a scanning electron microscope, bone marrow mesenchymal stem cel s grew wel on the surface of (glycolic acid-L-lysine-lactic acid)/poly lactic acid/β-tricalcium phosphate/nerve growth factor composite materials. Many protrusions ran out from the cel s, and they were woven into a mesh, which was typical performance of neuron-like cel s. These findings indicate that (glycolic acid-L-lysine-lactic acid)/poly lactic acid/β-tricalcium phosphate/nerve growth factor composite materials have good cytocompatibility with bone marrow mesenchymal stem cel s, which can be regarded as an excel ent carrier for artificial nerve construction.

  16. Enzymatic degradation behavior and cytocompatibility of silk fibroin–starch–chitosan conjugate membranes

    International Nuclear Information System (INIS)

    The objective of this study was to investigate the influence of silk fibroin and oxidized starch conjugation on the enzymatic degradation behavior and the cytocompatability of chitosan based biomaterials. The tensile stress of conjugate membranes, which was at 50 Megapascal (MPa) for the lowest fibroin and starch composition (10 weight percent (wt.%)), was decreased significantly with the increased content of fibroin and starch. The weight loss of conjugates in α-amylase was more notable when the starch concentration was the highest at 30 wt.%. The conjugates were resistant to the degradation by protease and lysozyme except for the conjugates with the lowest starch concentration. After 10 days of cell culture, the proliferation of osteoblast-like cells (SaOS-2) was stimulated significantly by higher fibroin compositions and the DNA synthesis on the conjugate with the highest fibroin (30 wt.%) was about two times more compared to the native chitosan. The light microscopy and the image analysis results showed that the cell area and the lengths were decreased significantly with higher fibroin/chitosan ratio. The study proved that the conjugation of fibroin and starch with the chitosan based biomaterials by the use of non-toxic reductive alkylation crosslinking significantly improved the cytocompatibility and modulated the biodegradation, respectively. - Highlights: ► Silk fibroin, starch and chitosan conjugates were prepared by reductive alkylation. ► The enzymatic biodegradation and the cytocompatibility of conjugates were tested. ► The conjugate with 30% starch composition was degraded by α-amylase significantly. ► Higher starch composition in conjugates prevented protease and lysozyme degradation. ► Fibroin incorporation effectively increased the cell proliferation of conjugates.

  17. Enzymatic degradation behavior and cytocompatibility of silk fibroin-starch-chitosan conjugate membranes

    Energy Technology Data Exchange (ETDEWEB)

    Baran, Erkan T., E-mail: erkantur@metu.edu.tr; Tuzlakoglu, Kadriye, E-mail: kadriye@dep.uminho.pt; Mano, Joao F., E-mail: jmano@dep.uminho.pt; Reis, Rui L., E-mail: rgreis@dep.uminho.pt

    2012-08-01

    The objective of this study was to investigate the influence of silk fibroin and oxidized starch conjugation on the enzymatic degradation behavior and the cytocompatability of chitosan based biomaterials. The tensile stress of conjugate membranes, which was at 50 Megapascal (MPa) for the lowest fibroin and starch composition (10 weight percent (wt.%)), was decreased significantly with the increased content of fibroin and starch. The weight loss of conjugates in {alpha}-amylase was more notable when the starch concentration was the highest at 30 wt.%. The conjugates were resistant to the degradation by protease and lysozyme except for the conjugates with the lowest starch concentration. After 10 days of cell culture, the proliferation of osteoblast-like cells (SaOS-2) was stimulated significantly by higher fibroin compositions and the DNA synthesis on the conjugate with the highest fibroin (30 wt.%) was about two times more compared to the native chitosan. The light microscopy and the image analysis results showed that the cell area and the lengths were decreased significantly with higher fibroin/chitosan ratio. The study proved that the conjugation of fibroin and starch with the chitosan based biomaterials by the use of non-toxic reductive alkylation crosslinking significantly improved the cytocompatibility and modulated the biodegradation, respectively. - Highlights: Black-Right-Pointing-Pointer Silk fibroin, starch and chitosan conjugates were prepared by reductive alkylation. Black-Right-Pointing-Pointer The enzymatic biodegradation and the cytocompatibility of conjugates were tested. Black-Right-Pointing-Pointer The conjugate with 30% starch composition was degraded by {alpha}-amylase significantly. Black-Right-Pointing-Pointer Higher starch composition in conjugates prevented protease and lysozyme degradation. Black-Right-Pointing-Pointer Fibroin incorporation effectively increased the cell proliferation of conjugates.

  18. Cytocompatibility of Siloxane-Containing Vaterite/Poly(l-lactic acid Composite Coatings on Metallic Magnesium

    Directory of Open Access Journals (Sweden)

    Shinya Yamada

    2013-12-01

    Full Text Available Poly(l-lactic acid-based films which include 60 wt % of vaterite (V or siloxane-containing vaterite (SiV were coated on a pure magnesium substrate, denoted by PLLA/V or PLLA/SiV, respectively, to suppress early corrosion and improve its cytocompatibility. Both coating films adhered to the Mg substrate with 2.3–2.8 MPa of tensile bonding strength. Soaking test for 7 days in α-modified minimum essential medium revealed that the morphological instability of the PLLA/V film caused a higher amount of Mg2+ ion to be released from the coating sample. On the other hand, in the case of the coating with the PLLA/SiV film, no morphological change even after the soaking test was observed, owing to the suppression of the degradation rate. In cell culture tests, the proliferation of mouse osteoblast-like cell (MC3T3-E1 was significantly enhanced by both coatings, in comparison with the uncoated magnesium substrate. The cell morphology revealed that a few less-spread cells were observed on the PLLA/V film, while more elongated cells were done on the PLLA/SiV film. The cells on the PLLA/SiV film exhibited an extremely higher alkaline phosphatase activity after 21 days of incubation than that on the PLLA/V one. The PLLA/SiV film suppressed the early corrosion and enhanced cytocompatibility on metallic magnesium.

  19. Development of highly luminescent and cytocompatible near-IR-emitting aqueous Ag2S quantum dots

    OpenAIRE

    Hocaoğlu, İbrahim; Sennaroğlu, Alphan ; Acar, Funda Havva Yağcı; Çizmeciyan, M. Natali; Erdem, Rengin ; Özen, Can ; Kurt, Adnan

    2012-01-01

    Colloidally stable and highly luminescent near-IR emitting Ag2S quantum dots (NIRQDs) were prepared by a very simple aqueous method using 2-mercaptopropionic acid (2MPA) as a coating. Emission of Ag2S-2MPA NIRQDs can be tuned between 780 and 950 nm. These NIRQDs have photoluminescence quantum yields (PLQY) around 7–39% and exhibit excellent cytocompatibility even at 600 mg mL 1 in NIH/3T3 cells. With such improved properties, Ag2S-2MPA NIRQDs have a great potential in practical...

  20. Enhancement of Polymer Cytocompatibility by Nanostructuring of Polymer Surface

    Czech Academy of Sciences Publication Activity Database

    Slepička, P.; Kasálková-Slepičková, N.; Bačáková, Lucie; Kolská, Z.; Švorčík, V.

    2012-01-01

    Roč. 2012, č. 2012 (2012), ID527403. ISSN 1687-4110 R&D Projects: GA ČR(CZ) GBP108/12/G108 Institutional support: RVO:67985823 Keywords : polymer cytocompatibility * polymer surface * nanotechnology Subject RIV: EI - Biotechnology ; Bionics Impact factor: 1.547, year: 2012

  1. Cytocompatibility studies of a biomimetic copolymer with simplified structure and high-strength adhesion.

    Science.gov (United States)

    Brennan, M Jane; Meredith, Heather J; Jenkins, Courtney L; Wilker, Jonathan J; Liu, Julie C

    2016-04-01

    The development of adhesives suitable for biomedical applications has been challenging given that these materials must exhibit sufficient adhesion strengths and biocompatibility. Biomimetic materials inspired by mussel adhesive proteins appear to contain many of the necessary characteristics for biomedical adhesives. In particular, poly[(3,4-dihydroxystyrene)-co-styrene] has been shown to be a high strength adhesive material with bonding comparable to or even greater than several commercial glues. Herein, a thorough study on the cytocompatibility of this copolymer provides insights on the suitability of a mussel-mimicking adhesive for applications development. The cytotoxicity of poly[(3,4-dihydroxystyrene)-co-styrene] was evaluated through assessment of the viability, proliferation rate, and morphology of NIH/3T3 fibroblasts when cultured with copolymer extracts or directly in contact with the adhesive. After 1 and 3 days of culture, both the copolymer alone and copolymer cross-linked with periodate exhibited minimal effects on cell viability. Likewise, cells cultured on the copolymer displayed proliferation rates and morphologies similar to cells on the poly-l-lysine control. These results indicate that poly[(3,4-dihydroxystyrene)-co-styrene] is highly cytocompatible and therefore a promising material for use where biological contact is important. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 104A: 983-990, 2016. PMID:26714824

  2. Enhanced cytocompatibility of silver-containing biointerface by constructing nitrogen functionalities

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Wei, E-mail: weizhang@mail.ipc.ac.cn [Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing 100190 (China); Liu, Jun [Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing 100190 (China); Wang, Huaiyu [Department of Physics & Materials Science, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong (China); Xu, Ying; Wang, Pingli [Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing 100190 (China); Ji, Junhui, E-mail: jhji@mail.ipc.ac.cn [Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing 100190 (China); Chu, Paul K. [Department of Physics & Materials Science, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong (China)

    2015-09-15

    Graphical abstract: Constructing nitrogen functionalities is promising method to enhance cytocompatibility of the biointerface by simultaneous Ag and N{sub 2} plasma modification. - Highlights: • N{sub 2} plasma immersion ion implantation (PIII) treatment generates plenty of nitrogen functionalities on polymer substrate. • N{sub 2} PIII treatment increases surface roughness and hydrophilicity and improves its capability to adsorb protein. • Simultaneous Ag and N{sub 2} plasma modification constructs nitrogen functionalities to enhance cytocompatibility of the biointerface. - Abstract: Silver (Ag) has recently been introduced into polymeric biomedical implants by plasma immersion ion implantation (PIII) to enhance the antibacterial capability. However, Ag ions and nanoparticles can increase the cytotoxicity and inhibit cellular proliferation and the relationship is time- and dose-dependent. In this study, Ag and N{sub 2} PIII is conducted in concert to produce nitrogen functional groups as well as Ag-containing biointerface. In addition to the creation of nitrogen functionalities, the surface roughness and hydrophilicity are improved in favor of protein adsorption. Compared to the biointerface created by Ag PIII only, the nitrogen functionalities generated by N{sub 2} co-PIII do not affect DNA synthesis and the total protein level but evidently enhance cellular adhesion, viability, and proliferation at the biointerface. The modified surface is observed to upregulate the osteogenesis-related marker expression of bone cells in contact. Our findings suggest that dual Ag and N{sub 2} PIII is a desirable technique to enhance both the cytocompatibility and antibacterial capability of medical polymers.

  3. Boron nitride nanotubes coated with organic hydrophilic agents: Stability and cytocompatibility studies

    Energy Technology Data Exchange (ETDEWEB)

    Ferreira, Tiago Hilário; Soares, Daniel Crístian Ferreira; Moreira, Luciana Mara Costa; Ornelas da Silva, Paulo Roberto [Serviço de Nanotecnologia, Centro de Desenvolvimento da Tecnologia Nuclear CDTN/CNEN, Avenida Presidente Antônio Carlos, 6.627, Campus da UFMG, Pampulha, CEP 31270-901 Belo Horizonte, Minas Gerais (Brazil); Gouvêa dos Santos, Raquel [Laboratório de Radiobiologia, Centro de Desenvolvimento da Tecnologia Nuclear CNEN/CDTN, Av. Presidente Antônio Carlos 6.627, Campus da UFMG, Pampulha, 31270-901 Belo Horizonte, Minas Gerais (Brazil); Barros de Sousa, Edésia Martins, E-mail: sousaem@cdtn.br [Serviço de Nanotecnologia, Centro de Desenvolvimento da Tecnologia Nuclear CDTN/CNEN, Avenida Presidente Antônio Carlos, 6.627, Campus da UFMG, Pampulha, CEP 31270-901 Belo Horizonte, Minas Gerais (Brazil)

    2013-12-01

    In the present study, Boron Nitride Nanotubes (BNNTs) were synthesized and functionalized with organic hydrophilic agents constituted by glucosamine (GA), polyethylene glycol (PEG){sub 1000}, and chitosan (CH) forming new singular systems. Their size, distribution, and homogeneity were determined by photon correlation spectroscopy, while their surface charge was determined by laser Doppler anemometry. The morphology and structural organization were evaluated by Transmission Electron Microscopy. The functionalization was evaluated by Thermogravimetry analysis and Fourier Transformer Infrared Spectroscopy. The results showed that BNNTs were successfully obtained and functionalized, reaching a mean size and dispersity deemed adequate for in vitro studies. The in vitro stability tests also revealed a good adhesion of functionalized agents on BNNT surfaces. Finally, the in vitro cytocompatibility of functionalized BNNTs against MCR-5 cells was evaluated, and the results revealed that none of the different functionalization agents disturbed the propagation of normal cells up to the concentration of 50 μg/mL. Furthermore, in this concentration, no significantly chromosomal or morphologic alterations or increase in ROS (Reactive Oxygen Species) could be observed. Thus, findings from the present study reveal an important stability and cytocompatibility of functionalized BNNTs as new potential drugs or radioisotope nanocarriers to be applied in therapeutic procedures. - Highlights: • BNNTs were synthesized and functionalized with organic hydrophilic agents. • Hydrophilic molecules do not alter the biocompatibility profile of BNNTs. • No significantly chromosomal or morphologic alterations in ROS could be observed.

  4. Guanidine hydrochloride embedded polyurethanes as antimicrobial and absorptive wound dressing membranes with promising cytocompatibility.

    Science.gov (United States)

    Sahraro, Maryam; Yeganeh, Hamid; Sorayya, Marziyeh

    2016-02-01

    Preparation and assessments of novel absorptive wound dressing materials with efficient antimicrobial activity as well as very good cytocompatibility were described in this work. An amine terminated poly(hexamethylene guanidine hydrochloride) was prepared and used as curing agent of different epoxy-terminated polyurethane prepolymers. The structures of prepared materials were elucidated by evaluation of their (1)H NMR and FTIR spectra. The recorded tensile strength of membranes confirmed the excellent dimensional stability of the film type dressings even at fully hydrated conditions. Therefore, these dressings could protect the wound bed from external forces during the healing period. The structurally optimized dressing membranes could preserve the desired moist environment over the wounded area, as a result of their balanced equilibrium, water absorption and water vapor transmission rate. Therefore, a very good condition for stimulation of self-healing of wound bed was attained. Also, owing to the presence of guanidine hydrochloride moieties embedded into the structure of dressings, efficient antimicrobial activity against Staphylococcus aureus, Pseudomonas aeruginosa and Candida albicans were detected. In vitro cytotoxicity assay of the prepared dressings revealed cytocompatibility of these materials against fibroblast cells. Therefore, they could support cell growth and proliferation at the wounded area. PMID:26652461

  5. Cytocompatibility studies of vertically-aligned multi-walled carbon nanotubes: Raw material and functionalized by oxygen plasma

    Energy Technology Data Exchange (ETDEWEB)

    Lobo, A.O., E-mail: loboao@yahoo.com [Laboratorio Associado de Sensores e Materiais, INPE, Sao Jose dos Campos/SP (Brazil); Instituto Tecnologico de Aeronautica, ITA, Sao Jose dos Campos/SP (Brazil); Laboratorio de Nanotecnologia Biomedica, Universidade do Vale do Paraiba, Sao Jose dos Campos/SP (Brazil); Corat, M.A.F. [Centro Multidisciplinar para Investigacao Biologica na Area da Ciencia em Animais de Laboratorio, CEMIB, UNICAMP, Campinas/SP (Brazil); Antunes, E.F. [Laboratorio Associado de Sensores e Materiais, INPE, Sao Jose dos Campos/SP (Brazil); Instituto Tecnologico de Aeronautica, ITA, Sao Jose dos Campos/SP (Brazil); Ramos, S.C. [Instituto Tecnologico de Aeronautica, ITA, Sao Jose dos Campos/SP (Brazil); Pacheco-Soares, C. [Laboratorio de Dinamica de Compartimentos Celulares, UNIVAP, Sao Jose dos Campos/SP (Brazil); and others

    2012-05-01

    It was presented a strong difference on cell adhesion and proliferation of functionalized vertically-aligned multi-walled carbon nanotube (VACNT) scaffolds compared to raw-VACNT. Biocompatibility in vitro tests were performed on raw-VACNT after superficial modification by oxygen plasma, which changes its superhydrophobic character to superhydrophilic. Two cytocompatibility tests were applied: 1) total lactate dehydrogenase colorimetric assay for the study of proliferating cells; and 2) cellular adhesion by scanning electron microscopy. Results showed that superhydrophilic VACNT scaffolds stimulate cell growth with proliferation up to 70% higher than normal growth of cell culture.

  6. Cytocompatibility studies of vertically-aligned multi-walled carbon nanotubes: Raw material and functionalized by oxygen plasma

    International Nuclear Information System (INIS)

    It was presented a strong difference on cell adhesion and proliferation of functionalized vertically-aligned multi-walled carbon nanotube (VACNT) scaffolds compared to raw-VACNT. Biocompatibility in vitro tests were performed on raw-VACNT after superficial modification by oxygen plasma, which changes its superhydrophobic character to superhydrophilic. Two cytocompatibility tests were applied: 1) total lactate dehydrogenase colorimetric assay for the study of proliferating cells; and 2) cellular adhesion by scanning electron microscopy. Results showed that superhydrophilic VACNT scaffolds stimulate cell growth with proliferation up to 70% higher than normal growth of cell culture.

  7. Effects of Polydopamine Functionalization on Boron Nitride Nanotube Dispersion and Cytocompatibility.

    Science.gov (United States)

    Fernandez-Yague, Marc A; Larrañaga, Aitor; Gladkovskaya, Olga; Stanley, Alanna; Tadayyon, Ghazal; Guo, Yina; Sarasua, Jose-Ramon; Tofail, Syed A M; Zeugolis, Dimitrios I; Pandit, Abhay; Biggs, Manus J

    2015-10-21

    Boron nitride nanotubes (BNNTs) have unique physical properties, of value in biomedical applications; however, their dispersion and functionalization represent a critical challenge in their successful employment as biomaterials. In the present study, we report a process for the efficient disentanglement of BNNTs via a dual surfactant/polydopamine (PD) process. High-resolution transmission electron microscopy (HR-TEM) indicated that individual BNNTs become coated with a uniform PD nanocoating, which significantly enhanced dispersion of BNNTs in aqueous solutions. Furthermore, the cytocompatibility of PD-coated BNNTs was assessed in vitro with cultured human osteoblasts (HOBs) at concentrations of 1, 10, and 30 μg/mL and over three time-points (24, 48, and 72 h). In this study it was demonstrated that PD-functionalized BNNTs become individually localized within the cytoplasm by endosomal escape and that concentrations of up to 30 μg/mL of PD-BNNTs were cytocompatible in HOBs cells following 72 h of exposure. PMID:26282841

  8. Cytocompatibility of titanium metal injection molding with various anodic oxidation post-treatments

    International Nuclear Information System (INIS)

    Metal injection molding (MIM) is a near net shape manufacturing method that allows for the production of components of small to moderate size and complex shape. MIM is a cost-effective and flexible manufacturing technique that provides a large innovative potential over existing methods for the industry of implantable devices. Commercially pure titanium (CP-Ti) samples were machined to the same shape as a composite feedstock with titanium and polyoxymethylene, and these metals were injected, debinded and sintered to assess comparative biological properties. Moreover, we treated MIM-Ti parts with BIOCOAT®, BIODIZE® and BIOCER®, three different anodic oxidation techniques that treat titanium using acid, alkaline and anion enriched electrolytes, respectively. Cytocompatibility as well as morphological and chemical features of surfaces was comparatively assessed on each sample, and the results revealed that MIM-Ti compared to CP-Ti demonstrated a specific surface topography with a higher roughness. MIM-Ti and BIOCER® samples significantly enhanced cell proliferation, cell adhesion and cell differentiation compared to CP-Ti. Interestingly, in the anodization post-treatment established in this study, we demonstrated the ability to improve osseointegration through anionic modification treatment. The excellent biological response we observed with MIM parts using the injection molding process represents a promising manufacturing method for the future implantable devices in direct contact with bones. - Highlights: ► Metal injection molding technique gives titanium a specific surface roughness. It enhances the biological response. ► Anodic oxidation method adds Ca, P, and Mg ions on the surface, promoting the cell adhesion. ► Cytocompatibility analyses show an increased cell adhesion and proliferation on MIM-Ti compared to pure titanium.

  9. Thiol-ene Photocrosslinking of Cytocompatible Resilin-Like Polypeptide-PEG Hydrogels.

    Science.gov (United States)

    McGann, Christopher L; Dumm, Rebekah E; Jurusik, Anna K; Sidhu, Ishnoor; Kiick, Kristi L

    2016-01-01

    A range of chemical strategies have been used for crosslinking recombinant polypeptide hydrogels, although only a few have employed photocrosslinking approaches. Here, we capitalize on the novel insect protein, resilin, and the versatility of click reactions to introduce a resilin-like polypeptide (RLP) that is capable of photoinitiated thiol-ene crosslinking. Lysine residues of the RLP were functionalized with norbornene acid as confirmed via 1H-NMR spectroscopy. The RLPNs were subsequently photocrosslinked with multi-arm PEG thiols in the presence of a photoinitiator to form elastic hybrid hydrogels. The crosslinking reaction and resulting RLP-PEG networks demonstrated cytocompatibility with human mesenchymal stem cells in both 2D cell-adhesion and 3D photoencapsulation studies. PMID:26435299

  10. Antibacterial properties and cytocompatibility of tantalum oxide coatings with different silver content

    International Nuclear Information System (INIS)

    Tantalum (Ta) oxides and their coatings have been proved to increase their applications in the biomedical fields by improving osseointegration and wear resistance. In this study, Ta oxide coatings containing different proportions of Ag are deposited on SS304 materials. A twin-gun magnetron sputtering system is used to deposit the tantalum oxide-Ag coating. In this study, Staphylococcus aureus, which exhibits physiological commensalism on the human skin, nares, and mucosal and oral areas, is chosen as the model for in vitro antibacterial analyses via a fluorescence staining method using Syto9. The cytocompatibility and adhesive morphology of human skin fibroblast cells (CCD-966SK) on the coatings are also determined by using the microculture tetrazolium assay. This study shows that Ta2O5 and Ta2O5-Ag coatings with 12.5 at. % of Ag exhibit improved antibacterial effects against S. aureus and have good skin fibroblast cell cellular biocompatibility

  11. The in vitro biomineralization and cytocompatibility of polydopamine coated carbon nanotubes

    International Nuclear Information System (INIS)

    In this work, polydopamine coated carbon nanotubes were firstly prepared by a simple and feasible route. Then, for comparison, the in vitro bioactivity and cytocompatibility of the carbon nanotubes and the polydopamine coated carbon nanotubes were assessed by immersion study in simulated body fluids and 3-(4,5-dimethyldiazol-2-yl)-2,5-diphenyl tetrazolium bromide test using osteoblast cells (MC3T3-E1), respectively. As a result, it has been demonstrated that the introduction of polydopamine coating can greatly enhance the bioactivity and promote cell proliferation of the carbon nanotubes. The improvement of bioactive behavior is attributed to the good combination of catecholamines structure of the polydopamine and the structural advantages of carbon nanotubes as a framework material. It is anticipated that the polydopamine coated carbon nanotubes would find potential applications in bone tissue engineering and other biomedical areas.

  12. In vitro bioactivity and cytocompatibility properties of spark plasma sintered HA-Ti composites.

    Science.gov (United States)

    Kumar, Alok; Dhara, Sharmistha; Biswas, Krishanu; Basu, Bikramjit

    2013-02-01

    The present study reports the results of the detailed in vitro bioactivity and cytocompatibility properties of the hydroxyapatite (HA) and the HA-titanium (HA-Ti) composite with varying amount of Ti (5, 10, and 20 wt %), densified using spark plasma sintering process (SPS). Using this technique and tailoring suitable processing parameters, it has been possible to retain both HA and Ti in the sintered ceramics. Importantly, the uniquely designed SPS processing with suitably chosen parameters enables in achieving better mechanical properties, such as higher indentation fracture toughness (~1.5 MPa m(1/2) ) in HA-Ti composites compared with HA. X-ray diffraction and scanning electron microscopic (SEM) observations reveal good bioactivity of the HA-Ti composites with the formation of thick, flaky, and porous apatite layer when immersed in simulated body fluid at 37°C and pH of 7.4. Atomic absorption spectroscopic analysis of the simulated body fluid solution reveals dynamic changes in Ca(+2) ion concentration with more dissolution of Ca(+2) ion from the HA-20Ti composite. However, the measurements with inductively coupled plasma spectrometer do not record dissolution of Ti(+4) ions. Transmission electron microscopic analysis indicates weak crystalline nature of the apatite and confirms the formation of fine-scale apatite crystals. MTT assay, fluorescence, and SEM study demonstrate good cell viability and cell adhesion/proliferation of the Saos -2 cells, cultured on the developed composites under standard culture condition, and the difference in cell viability has been discussed in reference to substrate composition and roughness. Overall, HA-Ti composites exhibit comparable and even better in vitro bioactivity and cytocompatibility properties than HA. PMID:23281190

  13. Cytocompatibility of Highly Dispersed Nano Hydroxyapatite Sol

    Institute of Scientific and Technical Information of China (English)

    MAOXuan; WUPei-zhu; TANGShun-qing; YANYan-ling; DAIYun

    2004-01-01

    Nano hydroxyapatite (HA) crystals were prepared and dispersed in water to form HA sol by simple methods. The cytotoxicity of the sols were tested by MTT assay and lymphocytotoxicity test. Results show that the average secondary particle size of the sol containing uncalcined HA crystals is around 750 nm, within micrograde; while the sol of calcined HA contains over 88% nanoparticles with the size between 65~86 nm, in which nano HA crystals are highly dispersed. Both the HA sols have no toxicity on the proliferation of 3T3 cells and lymphocytes. It demonstrates that the nano sol is safe for the application of drug delivery.

  14. Cytocompatibility of Plasma and Thermally Treated Biopolymers

    Directory of Open Access Journals (Sweden)

    Petr Slepička

    2013-01-01

    Full Text Available This paper is focused on the surface characterization of plasma and consequently thermally treated biocompatible polymers. PLLA (poly(L-lactide acid and PMP (poly-4-methyl-1-pentene are studied. The influence of Ar plasma treatment on the surface polarity of substrate measured immediately after treatment and during the polymer surface aging is studied. Surface roughness, morphology, wettability, and surface chemistry were determined. Plasma treatment leads to significant changes in PLLA surface morphology and chemistry, with the PMP being slightly affected. The higher resistance to plasma fluence results in smaller ablation of PMP than that of PLLA. The plasma treatment improves cell adhesion and proliferation on the PMP. Plasma treatment of PLLA influences mostly the homogeneity of adhered and proliferated VSMC.

  15. In vitro haematic proteins adsorption and cytocompatibility study on acrylic copolymer to realise coatings for drug-eluting stents

    International Nuclear Information System (INIS)

    In the present paper, a preliminary in vitro analysis of biocompatibility of newly-synthesised acrylic copolymers is reported. In particular, with the aim to obtain coatings for drug-eluting stents, blood protein absorption and cytocompatibility were studied. For protein absorption tests, bovine serum albumin and bovine plasma fibrinogen were considered. Cytocompatibility was tested using C2C12 cell line as model, analysing the behaviour of polymeric matrices and of drug-eluting systems, obtained loading polymeric matrices with paclitaxel, an anti-mitotic drug, in order to evaluate the efficacy of a pharmacological treatment locally administered from these materials. Results showed that the amount of albumin absorbed was greater than the amount of fibrinogen (comprised in the range of 70%–85% and 10%–22% respectively) and it is a good behaviour in terms of haemocompatibility. Cell culture tests showed good adhesion properties and a relative poor proliferation. In addition, a strong effect related to drug elution and a correlation with the macromolecular composition were detected. In this preliminary analysis, tested materials showed good characteristics and can be considered possible candidates to obtain coatings for drug-eluting stents. Highlights: ► Preliminary evaluation of haemo- and cytocompatibility of newly-synthesised acrylic copolymers ► Materials adsorb higher amounts of albumin and with a faster rate than fibrinogen. ► Protein adsorption depended on the macromolecular composition and surface properties. ► Cell viability on pure samples and efficacy of paclitaxel release were verified in C2C12 cultures.

  16. In vitro haematic proteins adsorption and cytocompatibility study on acrylic copolymer to realise coatings for drug-eluting stents

    Energy Technology Data Exchange (ETDEWEB)

    Gagliardi, Mariacristina, E-mail: mariacristina.gagliardi@iit.it

    2012-12-01

    In the present paper, a preliminary in vitro analysis of biocompatibility of newly-synthesised acrylic copolymers is reported. In particular, with the aim to obtain coatings for drug-eluting stents, blood protein absorption and cytocompatibility were studied. For protein absorption tests, bovine serum albumin and bovine plasma fibrinogen were considered. Cytocompatibility was tested using C2C12 cell line as model, analysing the behaviour of polymeric matrices and of drug-eluting systems, obtained loading polymeric matrices with paclitaxel, an anti-mitotic drug, in order to evaluate the efficacy of a pharmacological treatment locally administered from these materials. Results showed that the amount of albumin absorbed was greater than the amount of fibrinogen (comprised in the range of 70%-85% and 10%-22% respectively) and it is a good behaviour in terms of haemocompatibility. Cell culture tests showed good adhesion properties and a relative poor proliferation. In addition, a strong effect related to drug elution and a correlation with the macromolecular composition were detected. In this preliminary analysis, tested materials showed good characteristics and can be considered possible candidates to obtain coatings for drug-eluting stents. Highlights: Black-Right-Pointing-Pointer Preliminary evaluation of haemo- and cytocompatibility of newly-synthesised acrylic copolymers Black-Right-Pointing-Pointer Materials adsorb higher amounts of albumin and with a faster rate than fibrinogen. Black-Right-Pointing-Pointer Protein adsorption depended on the macromolecular composition and surface properties. Black-Right-Pointing-Pointer Cell viability on pure samples and efficacy of paclitaxel release were verified in C2C12 cultures.

  17. Influence of modified polyester on the material properties of collagen-based biocomposites and in vitro evaluation of cytocompatibility

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Chin-San, E-mail: t50008@cc.kyu.edu.tw

    2015-03-01

    The cytocompatibility of composite materials collagen (Col)/poly(hydroxyalkanoate) (PHA) and collagen/maleic anhydride-grafted PHA (PHA-g-MA) was investigated in this study. Col was homogeneously dispersed in the PHA-g-MA matrix as a result of condensation reactions. Mechanical characterisation indicated that the improved adhesion between Col and PHA-g-MA enhanced the tensile strength of the composite compared with that of PHA/Col. PHA-g-MA/Col composites were also more water-resistant than PHA/Col composites. Collagen and cell proliferation analysis indicated that PHA and PHA-g-MA and their composites were biocompatible with respect to FB proliferation. Cell-cycle and apoptosis assays by FBs on the PHA series composite samples were not affected by DNA content related to damage, i.e. rapid apoptosis/necrosis was not observed, demonstrating the potential of PHA/Col or PHA-g-MA/Col membranes for biomedical material applications. - Highlights: • Composites were prepared using polyester and collagen to explore their cytocompatibility. • The mechanical properties of the composite were significantly enhanced by the use of grafted polyester and collagen. • The polyester and collagen composites facilitated excellent cell viability and collagen production. • The cell cycle was not affected by DNA content related to damage, and it did not lead to rapid apoptosis or necrosis of the cells by the composite.

  18. Influence of modified polyester on the material properties of collagen-based biocomposites and in vitro evaluation of cytocompatibility

    International Nuclear Information System (INIS)

    The cytocompatibility of composite materials collagen (Col)/poly(hydroxyalkanoate) (PHA) and collagen/maleic anhydride-grafted PHA (PHA-g-MA) was investigated in this study. Col was homogeneously dispersed in the PHA-g-MA matrix as a result of condensation reactions. Mechanical characterisation indicated that the improved adhesion between Col and PHA-g-MA enhanced the tensile strength of the composite compared with that of PHA/Col. PHA-g-MA/Col composites were also more water-resistant than PHA/Col composites. Collagen and cell proliferation analysis indicated that PHA and PHA-g-MA and their composites were biocompatible with respect to FB proliferation. Cell-cycle and apoptosis assays by FBs on the PHA series composite samples were not affected by DNA content related to damage, i.e. rapid apoptosis/necrosis was not observed, demonstrating the potential of PHA/Col or PHA-g-MA/Col membranes for biomedical material applications. - Highlights: • Composites were prepared using polyester and collagen to explore their cytocompatibility. • The mechanical properties of the composite were significantly enhanced by the use of grafted polyester and collagen. • The polyester and collagen composites facilitated excellent cell viability and collagen production. • The cell cycle was not affected by DNA content related to damage, and it did not lead to rapid apoptosis or necrosis of the cells by the composite

  19. Physicochemical properties and in vitro cytocompatibility of modified titanium surfaces prepared via micro-arc oxidation with different calcium concentrations

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Sui-Dan; Zhang, Hui [Guanghua School of Stomatology, Hospital of Stomatology, Guangdong Key Laboratory of Stomatology, Sun Yat-sen University, Guangzhou 510055 (China); Dong, Xu-Dong [Faculty of Pharmaceutical Sciences, University of British Columbia, Vancouver, BC V6T 1Z3 (Canada); Ning, Cheng-Yun [College of Material Science and Engineering, South China University of Technology, Guangzhou 510641 (China); Fok, Alex S.L. [Minnesota Dental Research Center of Biomaterials and Biomechanics, School of Dentistry, University of Minnesota, Minneapolis, MN 55414 (United States); Wang, Yan, E-mail: wyan65@163.com [Guanghua School of Stomatology, Hospital of Stomatology, Guangdong Key Laboratory of Stomatology, Sun Yat-sen University, Guangzhou 510055 (China)

    2015-02-28

    Highlights: • MAO coating improves the surface characteristics and cytocompatibility of titanium. • Composition of MAO coating varies with the electrolyte concentration. • MAO coating properties can be optimized by adjusting the electrolyte concentration. • Higher CA concentration contributes to more favorable MAO coating cytocompatibility. - Abstract: Objective: To explore the effect of calcium concentration in the electrolyte solution on the physicochemical properties and biocompatibility of coatings formed by micro-arc oxidation (MAO) on titanium surfaces. Methods: The surfaces of pure titanium plates were modified by MAO in an electrolytic solution containing calcium acetate (CA; C{sub 4}H{sub 6}CaO{sub 4}) at concentrations of 0.05, 0.1, 0.2, or 0.3 M and β-glycerophosphate disodium salt pentahydrate (β-GP; C{sub 3}H{sub 7}Na{sub 2}O{sub 6}P·5H{sub 2}O) at a fixed concentration of 0.02 M. Surface topography, elemental characteristics, phase composition, and roughness were investigated by scanning electron microscopy, energy-dispersive X-ray analysis, X-ray diffraction, and a surface roughness tester, respectively. To assess the cytocompatibility and osteoinductivity of the surfaces, MC3T3-E1 preosteoblasts were cultured on the surfaces in vitro, and cell morphology, adhesion, proliferation, and differentiation were observed. Results: The porous MAO coating was composed primarily of TiO{sub 2} rutile and anatase. The amount of TiO{sub 2} rutile, the Ca/P ratio, and the surface roughness of the MAO coating increased with increasing CA concentration in the electrolyte solution. Ca{sub 3}(PO{sub 4}){sub 2}, CaCO{sub 3}, and CaTiO{sub 3} were formed on MAO-treated surfaces prepared with CA concentrations of 0.2 and 0.3 M. Cell proliferation and differentiation increased with increasing CA concentration, with MC3T3-E1 cells exhibiting favorable morphologies for bone–implant integration. Conclusions: MAO coating improves the surface characteristics and

  20. Physicochemical properties and in vitro cytocompatibility of modified titanium surfaces prepared via micro-arc oxidation with different calcium concentrations

    International Nuclear Information System (INIS)

    Highlights: • MAO coating improves the surface characteristics and cytocompatibility of titanium. • Composition of MAO coating varies with the electrolyte concentration. • MAO coating properties can be optimized by adjusting the electrolyte concentration. • Higher CA concentration contributes to more favorable MAO coating cytocompatibility. - Abstract: Objective: To explore the effect of calcium concentration in the electrolyte solution on the physicochemical properties and biocompatibility of coatings formed by micro-arc oxidation (MAO) on titanium surfaces. Methods: The surfaces of pure titanium plates were modified by MAO in an electrolytic solution containing calcium acetate (CA; C4H6CaO4) at concentrations of 0.05, 0.1, 0.2, or 0.3 M and β-glycerophosphate disodium salt pentahydrate (β-GP; C3H7Na2O6P·5H2O) at a fixed concentration of 0.02 M. Surface topography, elemental characteristics, phase composition, and roughness were investigated by scanning electron microscopy, energy-dispersive X-ray analysis, X-ray diffraction, and a surface roughness tester, respectively. To assess the cytocompatibility and osteoinductivity of the surfaces, MC3T3-E1 preosteoblasts were cultured on the surfaces in vitro, and cell morphology, adhesion, proliferation, and differentiation were observed. Results: The porous MAO coating was composed primarily of TiO2 rutile and anatase. The amount of TiO2 rutile, the Ca/P ratio, and the surface roughness of the MAO coating increased with increasing CA concentration in the electrolyte solution. Ca3(PO4)2, CaCO3, and CaTiO3 were formed on MAO-treated surfaces prepared with CA concentrations of 0.2 and 0.3 M. Cell proliferation and differentiation increased with increasing CA concentration, with MC3T3-E1 cells exhibiting favorable morphologies for bone–implant integration. Conclusions: MAO coating improves the surface characteristics and cytocompatibility of titanium for osseointegration. Higher CA concentration in the MAO

  1. Chemically crosslinked nanogels of PEGylated poly ethyleneimine (l-histidine substituted) synthesized via metal ion coordinated self-assembly for delivery of methotrexate: Cytocompatibility, cellular delivery and antitumor activity in resistant cells.

    Science.gov (United States)

    Abolmaali, Samira Sadat; Tamaddon, Ali Mohammad; Mohammadi, Samaneh; Amoozgar, Zohreh; Dinarvand, Rasoul

    2016-05-01

    Self-assembled nanogels were engineered by forming Zn(2+)-coordinated micellar templates of PEGylated poly ethyleneimine (PEG-g-PEI), chemical crosslinking and subsequent removal of the metal ion. Creation of stable micellar templates is a crucial step for preparing the nanogels. To this aim, imidazole moieties were introduced to the polymer by Fmoc-l-histidine using carbodiimide chemistry. It was hypothesized the nanogels loaded with methotrexate (MTX), a chemotherapeutic agent, circumvent impaired carrier activity in HepG2 cells (MTX-resistant hepatocellular carcinoma). So, the nanogels were post-loaded with MTX and characterized by (1)H-NMR, FTIR, dynamic light scattering-zeta potential, atomic force microscopy, and drug release experiments. Cellular uptake and the antitumor activity of MTX-loaded nanogels were investigated by flow cytometry and MTT assay. Discrete, spherical and uniform nanogels, with sizes about 77-83nm and a relatively high drug loading (54±4% w/w), showed a low polydispersity and neutral surface charges. The MTX-loaded nanogels, unlike empty nanogels, lowered viability of HepG2 cells; the nanogels demonstrated cell-cycle arrest and apoptosis comparably higher than MTX as free drug that was shown to be through i) cellular uptake of the nanogels by clathrin-mediated transport and ii) endosomolytic activity of the nanogels in HepG2 cells. These findings indicate the potential antitumor application of this preparation, which has to be investigated in-vivo. PMID:26952497

  2. In vitro degradation behavior and cytocompatibility of biodegradable AZ31 alloy with PEO/HT composite coating.

    Science.gov (United States)

    Tian, Peng; Liu, Xuanyong; Ding, Chuanxian

    2015-04-01

    Biodegradable magnesium-based implants have attracted much attention recently in orthopedic applications because of their good mechanical properties and biocompatibility. However, their rapid degradation in vivo will not only reduce their mechanical strength, but also induce some side effects, such as local alkalization and gas cavity, which may lead to a failure of the implant. In this work, a hydroxyapatite (HA) layer was prepared on plasma electrolytic oxidization (PEO) coating by hydrothermal treatment (HT) to fabricate a PEO/HT composite coating on biodegradable AZ31 alloy. The in vitro degradation behaviors of all samples were evaluated in simulated body fluid (SBF) and their surface cytocompatibility was also investigated by evaluating the adhesion and proliferation of osteoblast cells (MC3T3-E1). The results showed that the HA layer consisted of a dense inner layer and a needle-like outer layer, which successfully sealed the PEO coating. The in vitro degradation tests showed that the PEO/HT composite coating improved the corrosion resistance of AZ31 alloy in SBF, presenting nearly no severe local alkalization and hydrogen evolution. The lasting corrosion resistance of the PEO/HT composite coating may attribute to the new hydroxyapatite formation during the degradation process. Moreover, compared with AZ31 alloy and PEO coating, PEO/HT composite coating was more suitable for cells adhesion and proliferation, indicating improved surface cytocompatibility. The results show that the PEO/HT composite coating is promising as protective coating on biodegradable magnesium-based implants to enhance their corrosion resistance as well as improve their surface cytocompatibility for orthopedic applications. PMID:25731092

  3. Residual Detergent Detection Method for Nondestructive Cytocompatibility Evaluation of Decellularized Whole Lung Scaffolds.

    Science.gov (United States)

    Zvarova, Barbora; Uhl, Franziska E; Uriarte, Juan J; Borg, Zachary D; Coffey, Amy L; Bonenfant, Nicholas R; Weiss, Daniel J; Wagner, Darcy E

    2016-05-01

    The development of reliable tissue engineering methods using decellularized cadaveric or donor lungs could potentially provide a new source of lung tissue. The vast majority of current lung decellularization protocols are detergent based and incompletely removed residual detergents may have a deleterious impact on subsequent scaffold recellularization. Detergent removal and quality control measures that rigorously and reliably confirm removal, ideally utilizing nondestructive methods, are thus critical for generating optimal acellular scaffolds suitable for potential clinical translation. Using a modified and optimized version of a methylene blue-based detergent assay, we developed a straightforward, noninvasive method for easily and reliably detecting two of the most commonly utilized anionic detergents, sodium deoxycholate (SDC) and sodium dodecyl sulfate (SDS), in lung decellularization effluents. In parallel studies, we sought to determine the threshold of detergent concentration that was cytotoxic using four different representative human cell types utilized in the study of lung recellularization: human bronchial epithelial cells, human pulmonary vascular endothelial cells (CBF12), human lung fibroblasts, and human mesenchymal stem cells. Notably, different cells have varying thresholds for either SDC or SDS-based detergent-induced cytotoxicity. These studies demonstrate the importance of reliably removing residual detergents and argue that multiple cell lines should be tested in cytocompatibility-based assessments of acellular scaffolds. The detergent detection assay presented here is a useful nondestructive tool for assessing detergent removal in potential decellularization schemes or for use as a potential endpoint in future clinical schemes, generating acellular lungs using anionic detergent-based decellularization protocols. PMID:26905643

  4. Cytocompatible Poly(ethylene glycol)-co-polycarbonate Hydrogels Crosslinked by Copper-free, Strain-promoted “Click” Chemistry

    OpenAIRE

    Xu, Jianwen; Filion, Tera M.; Prifti, Fioleda; Song, Jie

    2011-01-01

    Strategies to encapsulate cells in cytocompatible 3-dimensional hydrogels with tunable mechanical properties and degradability without harmful gelling conditions are highly desired for regenerative medicine applications. Here we reported a method for preparing poly(ethylene glycol)-co-polycarbonate hydrogels through copper-free, strain-promoted azide-alkyne cycloaddition (SPAAC) “Click” chemistry. Hydrogels with varying mechanical properties were formed by “clicking” azido-functionalized poly...

  5. Polydopamine-Templated Hydroxyapatite Reinforced Polycaprolactone Composite Nanofibers with Enhanced Cytocompatibility and Osteogenesis for Bone Tissue Engineering.

    Science.gov (United States)

    Gao, Xiang; Song, Jinlin; Ji, Ping; Zhang, Xiaohong; Li, Xiaoman; Xu, Xiao; Wang, Mengke; Zhang, Siqi; Deng, Yi; Deng, Feng; Wei, Shicheng

    2016-02-10

    Nanohydroxyapatite (HA) synthesized by biomimetic strategy is a promising nanomaterial as bone substitute due to its physicochemical features similar to those of natural nanocrystal in bone tissue. Inspired by mussel adhesive chemistry, a novel nano-HA was synthesized in our work by employing polydopamine (pDA) as template under weak alkaline condition. Subsequently, the as-prepared pDA-templated HA (tHA) was introduced into polycaprolactone (PCL) matrix via coelectrospinning, and a bioactive tHA/PCL composite nanofiber scaffold was developed targeted at bone regeneration application. Our research showed that tHA reinforced PCL composite nanofibers exhibited favorable cytocompatibility at given concentration of tHA (0-10 w.t%). Compared to pure PCL and traditional nano-HA enriched PCL (HA/PCL) composite nanofibers, enhanced cell adhesion, spreading and proliferation of human mesenchymal stem cells (hMSCs) were observed on tHA/PCL composite nanofibers on account of the contribution of pDA present in tHA. More importantly, tHA nanoparticles exposed on the surface of composite nanofibers could further promote osteogenesis of hMSCs in vitro even in the absence of osteogenesis soluble inducing factors when compared to traditional HA/PCL scaffolds, which was supported by in vivo test as well according to the histological analysis. Overall, our study demonstrated that the developed tHA/PCL composite nanofibers with enhanced cytocompatibility and osteogenic capacity hold great potential as scaffolds for bone tissue engineering. PMID:26756224

  6. Anticorrosive effects and in vitro cytocompatibility of calcium silicate/zinc-doped hydroxyapatite composite coatings on titanium

    Science.gov (United States)

    Huang, Yong; Zhang, Honglei; Qiao, Haixia; Nian, Xiaofeng; Zhang, Xuejiao; Wang, Wendong; Zhang, Xiaoyun; Chang, Xiaotong; Han, Shuguang; Pang, Xiaofeng

    2015-12-01

    This work elucidated the corrosion resistance and cytocompatibility of electroplated Zn- and Si-containing bioactive calcium silicate/zinc-doped hydroxyapatite (ZnHA/CS) ceramic coatings on commercially pure titanium (CP-Ti). The formation of ZnHA/CS coating was investigated through Fourier transform infrared spectroscopy, X-ray diffraction (XRD), scanning electron microscopy, energy dispersive X-ray and inductively coupled plasma analyses. The XRD image showed that the reaction layer was mainly composed of HA and CaSiO3. The fabricated ZnHA/CS coatings presented a porous structure and appropriate thickness for possible applications in orthopaedic surgery. Potentiodynamic polarization tests showed that ZnHA/CS coatings exhibited higher corrosion resistance than CP-Ti. Dissolution tests on the coating also revealed that Si4+ and Zn2+ were leached at low levels. Moreover, MC3T3-E1 cells cultured on ZnHA/CS featured improved cell morphology, adhesion, spreading, proliferation and expression of alkaline phosphatase than those cultured on HA. The high cytocompatibility of ZnHA/CS could be mainly attributed to the combination of micro-porous surface effects and ion release (Zn2+ and Si4+). All these results indicate that ZnHA/CS composite-coated CP-Ti may be a potential material for orthopaedic applications.

  7. Blood-Vessel Mimicking Structures by Stereolithographic Fabrication of Small Porous Tubes Using Cytocompatible Polyacrylate Elastomers, Biofunctionalization and Endothelialization

    Directory of Open Access Journals (Sweden)

    Birgit Huber

    2016-04-01

    Full Text Available Blood vessel reconstruction is still an elusive goal for the development of in vitro models as well as artificial vascular grafts. In this study, we used a novel photo-curable cytocompatible polyacrylate material (PA for freeform generation of synthetic vessels. We applied stereolithography for the fabrication of arbitrary 3D tubular structures with total dimensions in the centimeter range, 300 µm wall thickness, inner diameters of 1 to 2 mm and defined pores with a constant diameter of approximately 100 µm or 200 µm. We established a rinsing protocol to remove remaining cytotoxic substances from the photo-cured PA and applied thio-modified heparin and RGDC-peptides to functionalize the PA surface for enhanced endothelial cell adhesion. A rotating seeding procedure was introduced to ensure homogenous endothelial monolayer formation at the inner luminal tube wall. We showed that endothelial cells stayed viable and adherent and aligned along the medium flow under fluid-flow conditions comparable to native capillaries. The combined technology approach comprising of freeform additive manufacturing (AM, biomimetic design, cytocompatible materials which are applicable to AM, and biofunctionalization of AM constructs has been introduced as BioRap® technology by the authors.

  8. Blood-Vessel Mimicking Structures by Stereolithographic Fabrication of Small Porous Tubes Using Cytocompatible Polyacrylate Elastomers, Biofunctionalization and Endothelialization.

    Science.gov (United States)

    Huber, Birgit; Engelhardt, Sascha; Meyer, Wolfdietrich; Krüger, Hartmut; Wenz, Annika; Schönhaar, Veronika; Tovar, Günter E M; Kluger, Petra J; Borchers, Kirsten

    2016-01-01

    Blood vessel reconstruction is still an elusive goal for the development of in vitro models as well as artificial vascular grafts. In this study, we used a novel photo-curable cytocompatible polyacrylate material (PA) for freeform generation of synthetic vessels. We applied stereolithography for the fabrication of arbitrary 3D tubular structures with total dimensions in the centimeter range, 300 µm wall thickness, inner diameters of 1 to 2 mm and defined pores with a constant diameter of approximately 100 µm or 200 µm. We established a rinsing protocol to remove remaining cytotoxic substances from the photo-cured PA and applied thio-modified heparin and RGDC-peptides to functionalize the PA surface for enhanced endothelial cell adhesion. A rotating seeding procedure was introduced to ensure homogenous endothelial monolayer formation at the inner luminal tube wall. We showed that endothelial cells stayed viable and adherent and aligned along the medium flow under fluid-flow conditions comparable to native capillaries. The combined technology approach comprising of freeform additive manufacturing (AM), biomimetic design, cytocompatible materials which are applicable to AM, and biofunctionalization of AM constructs has been introduced as BioRap(®) technology by the authors. PMID:27104576

  9. Effects of Zn Content on Crystal Structure, Cytocompatibility, Antibacterial Activity, and Chemical Stability in Zn-Modified Calcium Silicate Coatings

    Science.gov (United States)

    Li, Kai; Yu, Jiangming; Xie, Youtao; Huang, Liping; Ye, Xiaojian; Zheng, Xuebin

    2013-08-01

    In our previous study, Zn-modified calcium silicate coatings possess not only excellent chemical stability but also well antibacterial activity. Still, effects of zinc content on these properties and cytocompatibility remain unclear. In this paper, two kinds of Zn-modified calcium silicate coatings (ZC0.3, ZC0.5) were fabricated on Ti-6Al-4V substrates via plasma spraying technology. X-ray diffraction results and transmission electron microscopy observations showed that the ZC0.5 coating was composed of pure hardystonite (Ca2ZnSi2O7) phase, while, besides Ca2ZnSi2O7 phase, the amorphous CaSiO3 phase was also detected in the ZC0.3 coating. Chemical stability in Tris-HCl buffer solution and antibacterial activity of the Zn-modified calcium silicate coatings increased with an increase in zinc content. In vitro cytocompatibility evaluation demonstrated that the proliferation and alkaline phosphatase activity and collagen type I (COLI) secretion of osteoblast-like MC3T3-E1 cells on Zn-modified coatings were significantly enhanced compared to the Zn-free coating and Ti-6Al-4V control, and no cytotoxicity appeared on Zn-modified coatings. The better antibacterial activity and the enhanced capability to promote MC3T3-E1 cells differentiation of Zn-modified coatings should be attributed to the slow and constant Zn2+ releasing from the coatings.

  10. In Vitro Corrosion and Cytocompatibility of ZK60 Magnesium Alloy Coated with Hydroxyapatite by a Simple Chemical Conversion Process for Orthopedic Applications

    Directory of Open Access Journals (Sweden)

    Bing Wang

    2013-12-01

    Full Text Available Magnesium and its alloys—a new class of degradable metallic biomaterials—are being increasingly investigated as a promising alternative for medical implant and device applications due to their advantageous mechanical and biological properties. However, the high corrosion rate in physiological environments prevents the clinical application of Mg-based materials. Therefore, the objective of this study was to develop a hydroxyapatite (HA coating on ZK60 magnesium alloy substrates to mediate the rapid degradation of Mg while improving its cytocompatibility for orthopedic applications. A simple chemical conversion process was applied to prepare HA coating on ZK60 magnesium alloy. Surface morphology, elemental compositions, and crystal structures were characterized using scanning electron microscopy, energy dispersive spectroscopy, and X-ray diffraction, respectively. The corrosion properties of samples were investigated by immersion test and electrochemical test. Murine fibroblast L-929 cells were harvested and cultured with coated and non-coated ZK60 samples to determine cytocompatibility. The degradation results suggested that the HA coatings decreased the degradation of ZK60 alloy. No significant deterioration in compression strength was observed for all the uncoated and coated samples after 2 and 4 weeks’ immersion in simulated body fluid (SBF. Cytotoxicity test indicated that the coatings, especially HA coating, improved cytocompatibility of ZK60 alloy for L929 cells.

  11. Cytocompatibility and antibacterial properties of zirconia coatings with different silver contents on titanium

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Heng-Li [School of Dentistry, China Medical University, Taichung 404, Taiwan (China); Chang, Yin-Yu, E-mail: yinyu@mail2000.com.tw [Department of Mechanical and Computer-Aided Engineering, National Formosa University, Yunlin 632, Taiwan (China); Chen, Ya-Chi [Department of Materials Science and Engineering, Mingdao University, Changhua 52345, Taiwan (China); Lai, Chih-Ho [School of Medicine, China Medical University, Taichung 404, Taiwan (China); Chen, Michael Y.C. [School of Dentistry, China Medical University, Taichung 404, Taiwan (China); Division of Oral and Maxillofacial Surgery, China Medical University Hospital, Taichung 404, Taiwan (China)

    2013-12-31

    This study used a twin-gun magnetron sputtering system to deposit ZrO{sub 2}-silver (Ag) coatings on biograde pure-titanium implant materials, and the Ag content in the deposited coatings was controlled by the magnetron power. The films were then annealed using rapid thermal annealing at 350 °C for 2 min to induce the nucleation and growth of nanoparticles on the film surface. Staphylococcus aureus (S. aureus) and Actinobacillus actinomycetemcomitans (A. actinomycetemcomitans) were used for in vitro antibacterial analyses. The cytocompatibility, mRNA expression, and adhesive morphology of human gingival fibroblast (HGF) cells on the coatings were also determined. The obtained results suggest that ZrO{sub 2}-Ag composite coatings containing less than 10.6 at.% Ag show hydrophobicity, good viability and proliferation of HGF cells, and antibacterial effects on S. aureus and A. actinomycetemcomitans. Moreover, the antibacterial performance of ZrO{sub 2}-Ag coatings is superior to that pure-titanium whilst maintaining biological compatibility. - Highlights: • The annealed ZrO{sub 2}-Ag coatings showed a tetragonal-and-monoclinic structure. • Nanoparticles were well distributed in the annealed ZrO{sub 2}-Ag composite coatings. • The ZrO{sub 2}-Ag coated Ti showed hydrophobic feature. • The ZrO{sub 2}-Ag showed good antibacterial performance. • The ZrO{sub 2}-Ag showed good human gingival fibroblast cell viability.

  12. Rediscovering Chemical Gardens: Self-Assembling Cytocompatible Protein-Intercalated Silicate-Phosphate Sponge-Mimetic Tubules.

    Science.gov (United States)

    Punia, Kamia; Bucaro, Michael; Mancuso, Andrew; Cuttitta, Christina; Marsillo, Alexandra; Bykov, Alexey; L'Amoreaux, William; Raja, Krishnaswami S

    2016-08-30

    The classic chemical garden experiment is reconstructed to produce protein-intercalated silicate-phosphate tubules that resemble tubular sponges. The constructs were synthesized by seeding calcium chloride into a solution of sodium silicate-potassium phosphate and gelatin. Sponge-mimetic tubules were fabricated with varying percentages of gelatin (0-15% w/v), in diameters ranging from 200 μm to 2 mm, characterized morphologically and compositionally, functionalized with biomolecules for cell adhesion, and evaluated for cytocompatibility. Scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy analysis (EDS) experiments showed that the external surface of the tubules was relatively more amorphous in texture and carbon/protein-rich in comparison to the interior surface. Transmission electron microscopy (TEM) images indicate a network composed of gelatin incorporated into the inorganic scaffold. The presence of gelatin in the constructs was confirmed by infrared spectroscopy. Powder X-ray diffraction (XRD) was used to identify inorganic crystalline phases in the scaffolds that are mainly composed of Ca(OH)2, NaCl, and Ca2SiO4 along with a band corresponding to amorphous gelatin. Bioconjugation and coating protocols were developed to program the scaffolds with cues for cell adhesion, and the resulting constructs were employed for 3D cell culture of marine (Pyrocystis lunula) and mammalian (HeLa and H9C2) cell lines. The cytocompatibility of the constructs was demonstrated by live cell assays. We have successfully shown that these biomimetic materials can indeed support life; they serve as scaffolds that facilitate the attachment and assembly of individual cells to form multicellular entities, thereby revisiting the 350-year-old effort to link chemical gardens with the origins of life. Hybrid chemical garden biomaterials are programmable, readily fabricated and could be employed in tissue engineering, biomolecular materials development, 3D mammalian

  13. Effects of DCPD cement chemistry on degradation properties and cytocompatibility: comparison of MCPM/β-TCP and MCPM/HA formulations

    International Nuclear Information System (INIS)

    Dicalcium phosphate dihydrate (DCPD) cements are attractive biomaterials for bone repair, and a number of different DCPD cement formulations have been proposed in the literature. In this study, we have specifically compared monocalcium phosphate monohydrate (MCPM)/hydroxyapatite (HA) and MCPM/β-tricalcium phosphate (β-TCP) formulations to test the hypothesis that DCPD cement chemistry affects the degradation properties and cytocompatibility of the cement. Using simple in vitro models we found that MCPM/β-TCP formulations degraded primarily by DCPD dissolution, which was associated with a slight pH drop and relatively low mass loss. Cytocompatibility testing of cement conditioned culture media revealed no significant change in cell viability relative to the negative control for all of the MCPM/β-TCP formulations. In contrast, the MCPM/HA formulations were prone to undergo rapid conversion of DCPD to HA, resulting in a sharp pH drop and extensive mass loss. A stoichiometric excess of HA in the cement was found to accelerate the conversion process, and significant cytotoxicity was observed for the MCPM/HA formulations containing excess HA. Collectively, these results show that, although the product of the setting reaction is the same, DCPD cements produced with MCPM/HA and MCPM/β-TCP formulations differ significantly in their degradation properties and cytocompatibility. These differences may have important implications for the selection of a DCPD cement formulation for clinical application. (paper)

  14. Effect of Boron Addition on the Thermal, Degradation, and Cytocompatibility Properties of Phosphate-Based Glasses

    Directory of Open Access Journals (Sweden)

    Nusrat Sharmin

    2013-01-01

    Full Text Available In this study eight different phosphate-based glass compositions were prepared by melt-quenching: four in the (P2O545-(CaO16--(MgO24- system and four in the system (P2O550-(CaO16--(MgO24-, where and 10 mol%. The effect of B2O3 addition on the thermal properties, density, molar volume, dissolution rates, and cytocompatibility were studied for both glass systems. Addition of B2O3 increased the glass transition (, crystallisation (, melting (, Liquidus ( and dilatometric softening ( temperature and molar volume (. The thermal expansion coefficient (α and density ( were seen to decrease. An assessment of the thermal stability of the glasses was made in terms of their processing window (crystallisation onset, minus glass transition temperature, , and an increase in the processing window was observed with increasing B2O3 content. Degradation studies of the glasses revealed that the rates decreased with increasing B2O3 content and a decrease in degradation rates was also observed as the P2O5 content reduced from 50 to 45 mol%. MG63 osteoblast-like cells cultured in direct contact with the glass samples for 14 days revealed comparative data to the positive control for the cell metabolic activity, proliferation, ALP activity, and morphology for glasses containing up to 5 mol% of B2O3.

  15. Hydroxyapatite coatings with oriented nanoplate and nanorod arrays: Fabrication, morphology, cytocompatibility and osteogenic differentiation.

    Science.gov (United States)

    Chen, Wei; Tian, Bo; Lei, Yong; Ke, Qin-Fei; Zhu, Zhen-An; Guo, Ya-Ping

    2016-10-01

    Hydroxyapatite (HA) crystals exhibit rod-like shape with c-axis orientation and plate-like shape with a(b)-axis orientation in vertebrate bones and tooth enamel surfaces, respectively. Herein, we report the synthesis of HA coatings with the oriented nanorod arrays (RHACs) and HA coatings with oriented nanoplate arrays (PHACs) by using bioglass coatings as sacrificial templates. After soaking in simulated body fluid (SBF) at 120°C, the bioglass coatings are hydrothermally converted into the HA coatings via a dissolution-precipitation reaction. If the Ca/P ratios in SBF are 2.50 and 1.25, the HA crystals on the coatings are oriented nanorod arrays and oriented nanoplate arrays, respectively. Moreover, the bioglass coatings are treated with SBF at 37°C, plate-like HA coatings with a low crystallinity (SHACs) are prepared. As compared with the Ti6Al4V and SHACs, the human bone marrow stromal cells (hBMSCs) on the RHACs and PHACs have better cell adhesion, spreading, proliferation and osteogenic differentiation because of their moderately hydrophilic surfaces and similar chemical composition, morphology and crystal orientation to human hard tissues. Notably, the morphologies of HA crystals have no obvious effects on cytocompatibility and osteogenic differentiation. Hence, the HA coatings with oriented nanoplate arrays or oriented nanorod arrays have a great potential for orthopedic applications. PMID:27287136

  16. Antibacterial properties and cytocompatibility of tantalum oxide coatings with different silver content

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Heng-Li [School of Dentistry, China Medical University, Taichung 404, Taiwan (China); Chang, Yin-Yu, E-mail: yinyu@mail2000.com.tw; Chen, Hung-Jui; Chou, Yu-Kai [Department of Mechanical and Computer-Aided Engineering, National Formosa University, Yunlin 632, Taiwan (China); Lai, Chih-Ho [School of Medicine, China Medical University, Taichung 404, Taiwan (China); Chen, Michael Y. C. [Division of Oral and Maxillofacial Surgery, China Medical University Hospital, Taichung 404, Taiwan (China)

    2014-03-15

    Tantalum (Ta) oxides and their coatings have been proved to increase their applications in the biomedical fields by improving osseointegration and wear resistance. In this study, Ta oxide coatings containing different proportions of Ag are deposited on SS304 materials. A twin-gun magnetron sputtering system is used to deposit the tantalum oxide-Ag coating. In this study, Staphylococcus aureus, which exhibits physiological commensalism on the human skin, nares, and mucosal and oral areas, is chosen as the model for in vitro antibacterial analyses via a fluorescence staining method using Syto9. The cytocompatibility and adhesive morphology of human skin fibroblast cells (CCD-966SK) on the coatings are also determined by using the microculture tetrazolium assay. This study shows that Ta{sub 2}O{sub 5} and Ta{sub 2}O{sub 5}-Ag coatings with 12.5 at. % of Ag exhibit improved antibacterial effects against S. aureus and have good skin fibroblast cell cellular biocompatibility.

  17. PDMS-SiO2-TiO2-CaO hybrid materials - Cytocompatibility and nanoscale surface features.

    Science.gov (United States)

    Almeida, J Carlos; Wacha, András; Gomes, Pedro S; Fernandes, M Helena R; Fernandes, M Helena Vaz; Salvado, Isabel M Miranda

    2016-07-01

    Two PDMS-SiO2-TiO2-CaO porous hybrid materials were prepared using the same base composition, precursors, and solvents, but following two different sol-gel procedures, based on the authors' previous works where for the first time, in this hybrid system, calcium acetate was used as calcium source. The two different procedures resulted in monolithic materials with different structures, microstructures, and surface wettability. Even though both are highly hydrophobic (contact angles of 127.2° and 150.6°), and present different filling regimes due to different surface topographies, they have demonstrated to be cytocompatible when tested with human osteoblastic cells, against the accepted idea that high-hydrophobic surfaces are not suitable to cell adhesion and proliferation. At the nanoscale, the existence of hydrophilic silica domains containing calcium, where water molecules are physisorbed, is assumed to support this capability, as discussed. PMID:27127030

  18. Regular pattern formation on surface of aromatic polymers and its cytocompatibility

    Science.gov (United States)

    Michaljaničová, I.; Slepička, P.; Rimpelová, S.; Slepičková Kasálková, N.; Švorčík, V.

    2016-05-01

    In this work, we describe ripple and dot nanopatterning of three different aromatic polymer substrates by KrF excimer laser treatment. The conditions for regular structures were established by laser fluence and number of pulses. Subsequently, the influence of the angle of incidence of a laser beam was investigated. We have chosen polyethersulfone (PES), polyetherimide (PEI) and polyetheretherketone (PEEK) as substrates for modification since they are thermally, chemically and mechanically resistant aromatic polymers with high absorption coefficients at excimer laser wavelength. As a tool of wettability investigation, we used contact angle measurement and for determination of the absorption edge, UV-vis spectroscopy was used. Material surface chemistry was analyzed using FTIR and the changes caused by modification were gained as differential spectra by subtraction of the spectra of non-modified material. Surface morphology was investigated by atomic force microscopy, also the roughness and surface area of modified samples were studied. The scans showed the formation of regular periodic structures, ripples and dots, after treatment by 8 and 16 mJ cm-2 and 6000 pulses. Further, initial in vitro cytocompatibility tests were performed using U-2 OS cell line growing on PES samples subjected to scanning electron microscopy analysis. The structure formation mapping contributes strongly to development of new applications using nanostructured polymers, e.g. in tissue engineering or in combination with metallization in selected electronics and metamaterials construction.

  19. Cytocompatibility and antibacterial activity of titania nanotubes incorporated with gold nanoparticles.

    Science.gov (United States)

    Yang, Tingting; Qian, Shi; Qiao, Yuqing; Liu, Xuanyong

    2016-09-01

    TiO2 nanotubes prepared by electrochemical anodization have received considerable attention in the biomedical field. In this work, different amounts of gold nanoparticles were immobilized onto TiO2 nanotubes using 3-aminopropyltrimethoxysilane as coupling agent. Field emission scanning electron microscopy and X-ray photoelectron spectroscopy were used to investigate the surface morphology and composition. Photoluminescence spectra and surface zeta potential were also measured. The obtained results indicate that the surface modified gold nanoparticles can significantly enhance the electron storage capability and reduce the surface zeta potential compared to pristine TiO2 nanotubes. Moreover, the surface modified gold nanoparticles can stimulate initial adhesion and spreading of rat bone mesenchymal stem cells as well as proliferation, while the osteogenous performance of TiO2 nanotubes will not be reduced. The gold-modified surface presents moderate antibacterial effect on both Staphylococcus aureus and Escherichia coli. It should be noted that the surface modified fewer gold nanoparticles has better antibacterial effect compared to the surface of substantial modification of gold nanoparticles. Our study illustrates a composite surface with favorable cytocompatibility and antibacterial effect and provides a promising candidate for orthopedic and dental implant. PMID:27285731

  20. Improvement of cytocompatibility of polylactide by filling with marine algae powder

    International Nuclear Information System (INIS)

    This work evaluated the cytocompatibility, thermal and mechanical properties of composites of polylactide (PLA) and marine algae powder (MAP). To improve the thermal and mechanical properties of PLA–MAP composites, glycidyl methacrylate (GMA) was used as the compatibilizer for the blending of PLA and MAP. The PLA-g-GMA/MAP composites exhibited superior mechanical properties, attributing to higher compatibility between the polymer and MAP, comparing to PLA/MAP composites. The dispersion of MAP in the PLA-g-GMA matrix was highly homogeneous as a result of etherification. The lower melt torque of the PLA-g-GMA/MAP composites also made them more processable than PLA/MAP. To assess the cytocompatibility, normal human foreskin fibroblasts (FBs) were seeded onto each type of the composites. Results of FB proliferation, collagen production, and cytotoxicity assays indicated greater cytocompatibility for the PLA/MAP composites than for the PLA-g-GMA/MAP composites. Furthermore, both PLA/MAP and PLA-g-GMA/MAP composites were more cytocompatible than pure PLA. - Highlights: • PLA was grafted with GMA to form ether bond with marine algae powder (MAP). • Composites of PLA-g-GMA and MAP exhibited cytocompatibility with fibroblasts. • PLA-g-GMA/MAP composites exhibited mechanical properties superior to PLA/MAP. • PLA-g-GMA/MAP composites were more processable than PLA/MAP

  1. Improvement of cytocompatibility of polylactide by filling with marine algae powder

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Tung-Yi [Department of Materials Science and Engineering, National Taiwan University of Science and Technology, Taipei 10607, Taiwan (China); Yang, Ming-Chien, E-mail: myang@mail.ntust.edu.tw [Department of Materials Science and Engineering, National Taiwan University of Science and Technology, Taipei 10607, Taiwan (China); Hsu, Yi-Chiang [Graduate Institute of Medical Science, College of Health Sciences, Chang Jung Christian University, Tainan 71101, Taiwan (China); Innovative Research Center of Medicine, College of Health Sciences, Chang Jung Christian University, Tainan 71101, Taiwan (China)

    2015-05-01

    This work evaluated the cytocompatibility, thermal and mechanical properties of composites of polylactide (PLA) and marine algae powder (MAP). To improve the thermal and mechanical properties of PLA–MAP composites, glycidyl methacrylate (GMA) was used as the compatibilizer for the blending of PLA and MAP. The PLA-g-GMA/MAP composites exhibited superior mechanical properties, attributing to higher compatibility between the polymer and MAP, comparing to PLA/MAP composites. The dispersion of MAP in the PLA-g-GMA matrix was highly homogeneous as a result of etherification. The lower melt torque of the PLA-g-GMA/MAP composites also made them more processable than PLA/MAP. To assess the cytocompatibility, normal human foreskin fibroblasts (FBs) were seeded onto each type of the composites. Results of FB proliferation, collagen production, and cytotoxicity assays indicated greater cytocompatibility for the PLA/MAP composites than for the PLA-g-GMA/MAP composites. Furthermore, both PLA/MAP and PLA-g-GMA/MAP composites were more cytocompatible than pure PLA. - Highlights: • PLA was grafted with GMA to form ether bond with marine algae powder (MAP). • Composites of PLA-g-GMA and MAP exhibited cytocompatibility with fibroblasts. • PLA-g-GMA/MAP composites exhibited mechanical properties superior to PLA/MAP. • PLA-g-GMA/MAP composites were more processable than PLA/MAP.

  2. Ginkgo biloba: a natural reducing agent for the synthesis of cytocompatible graphene

    Directory of Open Access Journals (Sweden)

    Gurunathan S

    2014-01-01

    Full Text Available Sangiliyandi Gurunathan, Jae Woong Han, Jung Hyun Park, Vasuki Eppakayala, Jin-Hoi Kim Department of Animal Biotechnology, Konkuk University, Seoul, South Korea Background: Graphene is a novel two-dimensional planar nanocomposite material consisting of rings of carbon atoms with a hexagonal lattice structure. Graphene exhibits unique physical, chemical, mechanical, electrical, elasticity, and cytocompatible properties that lead to many potential biomedical applications. Nevertheless, the water-insoluble property of graphene restricts its application in various aspects of biomedical fields. Therefore, the objective of this work was to find a novel biological approach for an efficient method to synthesize water-soluble and cytocompatible graphene using Ginkgo biloba extract (GbE as a reducing and stabilizing agent. In addition, we investigated the biocompatibility effects of graphene in MDA-MB-231 human breast cancer cells. Materials and methods: Synthesized graphene oxide (GO and GbE-reduced GO (Gb-rGO were characterized using various sequences of techniques: ultraviolet-visible (UV-vis spectroscopy, Fourier-transform infrared spectroscopy (FTIR, dynamic light scattering (DLS, scanning electron microscopy (SEM, atomic force microscopy (AFM, and Raman spectroscopy. Biocompatibility of GO and Gb-rGO was assessed in human breast cancer cells using a series of assays, including cell viability, apoptosis, and alkaline phosphatase (ALP activity. Results: The successful synthesis of graphene was confirmed by UV-vis spectroscopy and FTIR. DLS analysis was performed to determine the average size of GO and Gb-rGO. X-ray diffraction studies confirmed the crystalline nature of graphene. SEM was used to investigate the surface morphologies of GO and Gb-rGO. AFM was employed to investigate the morphologies of prepared graphene and the height profile of GO and Gb-rGO. The formation of defects in Gb-rGO was confirmed by Raman spectroscopy. The biocompatibility

  3. Barium Titanate Nanoparticles: Highly Cytocompatible Dispersions in Glycol-chitosan and Doxorubicin Complexes for Cancer Therapy

    Directory of Open Access Journals (Sweden)

    Danti Serena

    2010-01-01

    Full Text Available Abstract In the latest years, innovative nanomaterials have attracted a dramatic and exponentially increasing interest, in particular for their potential applications in the biomedical field. In this paper, we reported our findings on the cytocompatibility of barium titanate nanoparticles (BTNPs, an extremely interesting ceramic material. A rational and systematic study of BTNP cytocompatibility was performed, using a dispersion method based on a non-covalent binding to glycol-chitosan, which demonstrated the optimal cytocompatibility of this nanomaterial even at high concentration (100 μg/ml. Moreover, we showed that the efficiency of doxorubicin, a widely used chemotherapy drug, is highly enhanced following the complexation with BTNPs. Our results suggest that innovative ceramic nanomaterials such as BTNPs can be realistically exploited as alternative cellular nanovectors.

  4. Composite bone cements loaded with a bioactive and ferrimagnetic glass-ceramic: Leaching, bioactivity and cytocompatibility.

    Science.gov (United States)

    Verné, Enrica; Bruno, Matteo; Miola, Marta; Maina, Giovanni; Bianco, Carlotta; Cochis, Andrea; Rimondini, Lia

    2015-08-01

    In this work, composite bone cements, based on a commercial polymethylmethacrylate matrix (Palamed®) loaded with ferrimagnetic bioactive glass-ceramic particles (SC45), were produced and characterized in vitro. The ferrimagnetic bioactive glass-ceramic belongs to the system SiO2-Na2O-CaO-P2O5-FeO-Fe2O3 and contains magnetite (Fe3O4) crystals into a residual amorphous bioactive phase. Three different formulations (containing 10, 15 and 20 wt.% of glass-ceramic particles respectively) have been investigated. These materials are intended to be applied as bone fillers for the hyperthermic treatment of bone tumors. The morphological, compositional, calorimetric and mechanical properties of each formulation have been already discussed in a previous paper. The in vitro properties of the composite bone cements described in the present paper are related to iron ion leaching test (by graphite furnace atomic absorption spectrometer), bioactivity (i.e. the ability to stimulate the formation of a hydroxyapatite - HAp - layer on their surface after soaking in simulated body fluid SBF) and cytocompatibility toward human osteosarcoma cells (ATCC CRL-1427, Mg63). Morphological and chemical characterizations by scanning electron microscopy and energy dispersion spectrometry have been performed on the composite samples after each test. The iron release was negligible and all the tested samples showed the growth of HAp on their surface after 28 days of immersion in a simulated body fluid (SBF). Cells showed good viability, morphology, adhesion, density and the ability to develop bridge-like structures on all investigated samples. A synergistic effect between bioactivity and cell mineralization was also evidenced. PMID:26042695

  5. Effects of fluoride-ion-implanted titanium surface on the cytocompatibility in vitro and osseointegatation in vivo for dental implant applications.

    Science.gov (United States)

    Wang, Xue-jin; Liu, Hui-ying; Ren, Xiang; Sun, Hui-yan; Zhu, Li-ying; Ying, Xiao-xia; Hu, Shu-hai; Qiu, Ze-wen; Wang, Lang-ping; Wang, Xiao-feng; Ma, Guo-wu

    2015-12-01

    As an attractive technique for the improvement of biomaterials, Plasma immersion ion implantation (PIII) has been applied to modifying the titanium material for dental implant application. The present study investigated the cytocompatibility and early osseointegration of fluoride-ion-implanted titanium (F-Ti) surface and implants, both characterizing in their composition of titanium oxide and titanium fluoride. The cytocompatibility of F-Ti was evaluated in vitro by using scanning electron microscope, Cell Counting Kit-8 assay, alkaline phosphatase activity assay, and quantitative real-time polymerase chain reaction. The results showed that the F-Ti weakened the effects that Porphyromonas gingivalis exerted on the MG-63 cells in terms of morphology, proliferation, differentiation, and genetic expression when MG-63 cells and Porphyromonas gingivalis were co-cultured on the surface of F-Ti. Meanwhile, the osteogenic activity of F-Ti implants was assessed in vivo via evaluating the histological morphology and estimating histomorphometric parameters. The analysis of toluidine blue staining indicated that the new bone was more mature in subjects with F-Ti group, which exhibited the Haversian system, and the mean bone-implant contact value of F-Ti group was slightly higher than that of cp-Ti group (p>0.05). Fluorescence bands were wider and brighter in the F-Ti group, and the intensity of fluorochromes deposited at the sites of mineralized bone formation was significantly higher for F-Ti surfaces than for cp-Ti surfaces, within the 2nd, 3rd and 4th weeks (p<0.05). An indication is that the fluoride modified titanium can promote cytocompatibility and early osseointegration, thus providing a promising alternative for clinical use. PMID:26519937

  6. Characterization and cytocompatibility of a new injectable multiphasic bone substitute based on a combination of polysaccharide gel-coated OSPROLIFE(®) HA/TTCP granules and bone marrow concentrate.

    Science.gov (United States)

    Pierini, Michela; Lucarelli, Enrico; Duchi, Serena; Prosperi, Susanna; Preve, Eleonora; Piccinini, Marzio; Bucciotti, Francesco; Donati, Davide

    2016-07-01

    The purpose of this study was to examine the in vitro cytocompatibility of a novel injectable multiphasic bone substitute (MBS) based on polysaccharide gel-coated OSPROLIFE(®) hydroxyapatite (HA)/tetracalcium phosphate (TTCP) granules combined with bone marrow concentrate (BMC). Polysaccharide gel-coated granules loaded in syringe were combined with BMC diluted in ionic crosslinking solution. The product was then maintained in culture to investigate the cytocompatibility, distribution, and osteogenic differentiation function of cells contained in the BMC. The in vitro cytocompatibility was assessed after 0, 24, and 96 h from the injectable MBS preparation using the LIVE/DEAD(®) staining kit. The results highlighted that cells remained viable after combination with the polysaccharide gel-coated granules; also, viability was maintained over time. The distribution of the cells in the product, observed using confocal microscopy, showed viable cells immersed in the polysaccharide gel formed between the granules after ionic crosslinking. The mesenchymal stromal cells (MSC) contained in the injectable MBS, the basic elements for bone tissue regeneration, were able to differentiate toward osteoblasts, producing an osteogenic matrix as evidenced by alizarin red-s (AR-S) staining. In conclusion, we found that the injectable MBS may have the potential to be used as a bone substitute by applying a "one-step" procedure in bone tissue engineering applications. © 2015 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 104B: 894-902, 2016. PMID:25952003

  7. Niobium-Doped Hydroxyapatite Bioceramics: Synthesis, Characterization and In Vitro Cytocompatibility

    Directory of Open Access Journals (Sweden)

    Nádia S. V. Capanema

    2015-07-01

    Full Text Available Doping calcium phosphates with ionic species can play an important role in biological responses promoting alkaline phosphatase activity, and, therefore inducing the generation of new bone. Thus, in this study, the synthesis of niobium-doped hydroxyapatite (Nb-HA nanosize particles obtained by the precipitation process in aqueous media followed by thermal treatment is presented. The bioceramics were extensively characterized by X-ray diffraction, wavelength dispersive X-ray fluorescence spectrometry, Fourier transform infrared spectroscopy, scanning electron microscopy/energy dispersive X-ray spectroscopy analysis, transmission electron microscopy, atomic force microscopy and thermal analysis regarding their chemical composition, structure and morphology. The results showed that the precipitate dried at 110 °C was composed of amorphous calcium phosphate and HA, with polidisperse particles ranging from micro to nano dimensions. After the thermal treatment at 900 °C, the bioceramic system evolved predominantly to HA crystalline phase, with evident features of particle sintering and reduction of surface area. Moreover, the addition of 10 mol% of niobium salt precursor during the synthesis indicated the complete incorporation of the Nb(V species in the HA crystals with detectable changes in the original lattice parameters. Furthermore, the incorporation of Nb ions caused a significant refinement on the average particle size of HA. Finally, the preliminary cytocompatibility response of the biomaterials was accessed by human osteoblast cell culture using MTT and resazurin assays, which demonstrated no cytotoxicity of the Nb-alloyed hydroxyapatite. Thus, these findings seem promising for developing innovative Nb-doped calcium phosphates as artificial biomaterials for potential use in bone replacements and repair.

  8. Cytocompatibility and biocompatibility of nanostructured carbonated hydroxyapatite spheres for bone repair

    Science.gov (United States)

    CALASANS-MAIA, Mônica Diuana; de MELO, Bruno Raposo; ALVES, Adriana Terezinha Neves Novellino; RESENDE, Rodrigo Figueiredo de Brito; LOURO, Rafael Seabra; SARTORETTO, Suelen Cristina; GRANJEIRO, José Mauro; ALVES, Gutemberg Gomes

    2015-01-01

    ABSTRACT Objective The aim of this study was to investigate the in vitro and in vivo biological responses to nanostructured carbonated hydroxyapatite/calcium alginate (CHA) microspheres used for alveolar bone repair, compared to sintered hydroxyapatite (HA). Material and Methods The maxillary central incisors of 45 Wistar rats were extracted, and the dental sockets were filled with HA, CHA, and blood clot (control group) (n=5/period/group). After 7, 21 and 42 days, the samples of bone with the biomaterials were obtained for histological and histomorphometric analysis, and the plasma levels of RANKL and OPG were determined via immunoassay. Statistical analysis was performed by Two-Way ANOVA with post-hoc Tukey test at 95% level of significance. Results The CHA and HA microspheres were cytocompatible with both human and murine cells on an in vitro assay. Histological analysis showed the time-dependent increase of newly formed bone in control group characterized by an intense osteoblast activity. In HA and CHA groups, the presence of a slight granulation reaction around the spheres was observed after seven days, which was reduced by the 42nd day. A considerable amount of newly formed bone was observed surrounding the CHA spheres and the biomaterials particles at 42-day time point compared with HA. Histomorphometric analysis showed a significant increase of newly formed bone in CHA group compared with HA after 21 and 42 days from surgery, moreover, CHA showed almost 2-fold greater biosorption than HA at 42 days (two-way ANOVA, p<0.05) indicating greater biosorption. An increase in the RANKL/OPG ratio was observed in the CHA group on the 7th day. Conclusion CHA spheres were osteoconductive and presented earlier biosorption, inducing early increases in the levels of proteins involved in resorption. PMID:26814461

  9. In vitro hemocompatibility and cytocompatibility of dexamethasone-eluting PLGA stent coatings

    International Nuclear Information System (INIS)

    Highlights: • Biodegradable dexamethasone-eluting PLGA stent coatings were developed. • Stent coatings can withstand the compressive and tensile strains without cracking. • Stent coatings presented favorable release kinetic for the lesion site. • Stent coatings can effectively inhibit the adhesion and activation of platelets. • Stent coatings can effectively inhibit the proliferation of SMC. - Abstract: Drug-eluting stents (DESs) have been an important breakthrough for interventional cardiology applications since 2002. Though successful in reducing restenosis, some adverse clinical problems still emerged, which were mostly caused by the bare-metal stents and non-biodegradable polymer coatings, associated with the delayed endothelialization process. In this study, dexamethasone-loaded poly (lactic-co-glycolic acid) (PLGA) coatings were developed to explore the potential application of dexamethasone-eluting stents. Dexamethasone-eluting PLGA stents were prepared using ultrasonic atomization spray method. For other tests like stability and cytocompatibility and hemocompatibility tests, dexamethasone loaded coatings were deposited on 316L SS wafers. Fourier transform-infrared spectroscopy (FT-IR) results demonstrated that there was no chemical reaction between PLGA and dexamethasone. The balloon expansion experiment and surface morphology observation suggested that the stent coatings were smooth and uniform, and could also withstand the compressive and tensile strains imparted without cracking after stent expansion. The drug release behavior in vitro indicated that dexamethasone existed burst release within 1 day, but it presented linear release characteristics after 6 days. In vitro platelets adhesion, activation test and APTT test were also done, which showed that after blending dexamethasone into PLGA, the hemocompatibility was improved. Besides, dexamethasone and dexamethasone-loaded PLGA coatings could significantly inhibit the attachment and

  10. In vitro hemocompatibility and cytocompatibility of dexamethasone-eluting PLGA stent coatings

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Jiang; Liu, Yang; Luo, Rifang; Chen, Si; Li, Xin; Yuan, Shuheng; Wang, Jin, E-mail: jinxxwang@263.net; Huang, Nan

    2015-02-15

    Highlights: • Biodegradable dexamethasone-eluting PLGA stent coatings were developed. • Stent coatings can withstand the compressive and tensile strains without cracking. • Stent coatings presented favorable release kinetic for the lesion site. • Stent coatings can effectively inhibit the adhesion and activation of platelets. • Stent coatings can effectively inhibit the proliferation of SMC. - Abstract: Drug-eluting stents (DESs) have been an important breakthrough for interventional cardiology applications since 2002. Though successful in reducing restenosis, some adverse clinical problems still emerged, which were mostly caused by the bare-metal stents and non-biodegradable polymer coatings, associated with the delayed endothelialization process. In this study, dexamethasone-loaded poly (lactic-co-glycolic acid) (PLGA) coatings were developed to explore the potential application of dexamethasone-eluting stents. Dexamethasone-eluting PLGA stents were prepared using ultrasonic atomization spray method. For other tests like stability and cytocompatibility and hemocompatibility tests, dexamethasone loaded coatings were deposited on 316L SS wafers. Fourier transform-infrared spectroscopy (FT-IR) results demonstrated that there was no chemical reaction between PLGA and dexamethasone. The balloon expansion experiment and surface morphology observation suggested that the stent coatings were smooth and uniform, and could also withstand the compressive and tensile strains imparted without cracking after stent expansion. The drug release behavior in vitro indicated that dexamethasone existed burst release within 1 day, but it presented linear release characteristics after 6 days. In vitro platelets adhesion, activation test and APTT test were also done, which showed that after blending dexamethasone into PLGA, the hemocompatibility was improved. Besides, dexamethasone and dexamethasone-loaded PLGA coatings could significantly inhibit the attachment and

  11. Composite bone cements loaded with a bioactive and ferrimagnetic glass-ceramic: Leaching, bioactivity and cytocompatibility

    Energy Technology Data Exchange (ETDEWEB)

    Verné, Enrica, E-mail: enrica.verne@polito.it [Institute of Materials Physics and Engineering, Applied Science and Technology Department, Politecnico di Torino, C. so Duca degli Abruzzi 24, 10129 Torino (Italy); Bruno, Matteo [Institute of Materials Physics and Engineering, Applied Science and Technology Department, Politecnico di Torino, C. so Duca degli Abruzzi 24, 10129 Torino (Italy); Miola, Marta [Institute of Materials Physics and Engineering, Applied Science and Technology Department, Politecnico di Torino, C. so Duca degli Abruzzi 24, 10129 Torino (Italy); Department of Health Sciences, Università del Piemonte Orientale “Amedeo Avogadro”, Via Solaroli 17, 28100 Novara (Italy); Maina, Giovanni; Bianco, Carlotta [Traumatology Orthopedics and Occupational Medicine Dept., Università di Torino, Via G. Zuretti 29, 10126 Torino (Italy); Cochis, Andrea [Department of Health Sciences, Università del Piemonte Orientale “Amedeo Avogadro”, Via Solaroli 17, 28100 Novara (Italy); Rimondini, Lia [Department of Health Sciences, Università del Piemonte Orientale “Amedeo Avogadro”, Via Solaroli 17, 28100 Novara (Italy); Consorzio Interuniversitario Nazionale per la Scienza e Tecnologia dei Materiali, Via G. Giusti, 9, 50121 Firenze (Italy)

    2015-08-01

    In this work, composite bone cements, based on a commercial polymethylmethacrylate matrix (Palamed®) loaded with ferrimagnetic bioactive glass-ceramic particles (SC45), were produced and characterized in vitro. The ferrimagnetic bioactive glass-ceramic belongs to the system SiO{sub 2}–Na{sub 2}O–CaO–P{sub 2}O{sub 5}–FeO–Fe{sub 2}O{sub 3} and contains magnetite (Fe{sub 3}O{sub 4}) crystals into a residual amorphous bioactive phase. Three different formulations (containing 10, 15 and 20 wt.% of glass-ceramic particles respectively) have been investigated. These materials are intended to be applied as bone fillers for the hyperthermic treatment of bone tumors. The morphological, compositional, calorimetric and mechanical properties of each formulation have been already discussed in a previous paper. The in vitro properties of the composite bone cements described in the present paper are related to iron ion leaching test (by graphite furnace atomic absorption spectrometer), bioactivity (i.e. the ability to stimulate the formation of a hydroxyapatite – HAp – layer on their surface after soaking in simulated body fluid SBF) and cytocompatibility toward human osteosarcoma cells (ATCC CRL-1427, Mg63). Morphological and chemical characterizations by scanning electron microscopy and energy dispersion spectrometry have been performed on the composite samples after each test. The iron release was negligible and all the tested samples showed the growth of HAp on their surface after 28 days of immersion in a simulated body fluid (SBF). Cells showed good viability, morphology, adhesion, density and the ability to develop bridge-like structures on all investigated samples. A synergistic effect between bioactivity and cell mineralization was also evidenced. - Highlights: • An in vitro biological characterization was carried out on ferromagnetic and bioactive composite cements. • No release of iron was revealed in the physiological solution. • Bioactivity tests

  12. Composite bone cements loaded with a bioactive and ferrimagnetic glass-ceramic: Leaching, bioactivity and cytocompatibility

    International Nuclear Information System (INIS)

    In this work, composite bone cements, based on a commercial polymethylmethacrylate matrix (Palamed®) loaded with ferrimagnetic bioactive glass-ceramic particles (SC45), were produced and characterized in vitro. The ferrimagnetic bioactive glass-ceramic belongs to the system SiO2–Na2O–CaO–P2O5–FeO–Fe2O3 and contains magnetite (Fe3O4) crystals into a residual amorphous bioactive phase. Three different formulations (containing 10, 15 and 20 wt.% of glass-ceramic particles respectively) have been investigated. These materials are intended to be applied as bone fillers for the hyperthermic treatment of bone tumors. The morphological, compositional, calorimetric and mechanical properties of each formulation have been already discussed in a previous paper. The in vitro properties of the composite bone cements described in the present paper are related to iron ion leaching test (by graphite furnace atomic absorption spectrometer), bioactivity (i.e. the ability to stimulate the formation of a hydroxyapatite – HAp – layer on their surface after soaking in simulated body fluid SBF) and cytocompatibility toward human osteosarcoma cells (ATCC CRL-1427, Mg63). Morphological and chemical characterizations by scanning electron microscopy and energy dispersion spectrometry have been performed on the composite samples after each test. The iron release was negligible and all the tested samples showed the growth of HAp on their surface after 28 days of immersion in a simulated body fluid (SBF). Cells showed good viability, morphology, adhesion, density and the ability to develop bridge-like structures on all investigated samples. A synergistic effect between bioactivity and cell mineralization was also evidenced. - Highlights: • An in vitro biological characterization was carried out on ferromagnetic and bioactive composite cements. • No release of iron was revealed in the physiological solution. • Bioactivity tests show hydroxyapatite precipitates on the cement

  13. Poly(hydroxybutyrate)/cellulose acetate blend nanofiber scaffolds: Preparation, characterization and cytocompatibility.

    Science.gov (United States)

    Zhijiang, Cai; Yi, Xu; Haizheng, Yang; Jia, Jianru; Liu, Yuanpei

    2016-01-01

    Poly(hydroxybutyrate) (PHB)/cellulose acetate (CA) blend nanofiber scaffolds were fabricated by electrospinning using the blends of chloroform and DMF as solvent. The blend nanofiber scaffolds were characterized by SEM, FTIR, XRD, DSC, contact angle and tensile test. The blend nanofibers exhibited cylindrical, uniform, bead-free and random orientation with the diameter ranged from 80-680 nm. The scaffolds had very well interconnected porous fibrous network structure and large aspect surface areas. It was found that the presence of CA affected the crystallization of PHB due to formation of intermolecular hydrogen bonds, which restricted the preferential orientation of PHB molecules. The DSC result showed that the PHB and CA were miscible in the blend nanofiber. An increase in the glass transition temperature was observed with increasing CA content. Additionally, the mechanical properties of blend nanofiber scaffolds were largely influenced by the weight ratio of PHB/CA. The tensile strength, yield strength and elongation at break of the blend nanofiber scaffolds increased from 3.3 ± 0.35 MPa, 2.8 ± 0.26 MPa, and 8 ± 0.77% to 5.05 ± 0.52 MPa, 4.6 ± 0.82 MPa, and 17.6 ± 1.24% by increasing PHB content from 60% to 90%, respectively. The water contact angle of blend nanofiber scaffolds decreased about 50% from 112 ± 2.1° to 60 ± 0.75°. The biodegradability was evaluated by in vitro degradation test and the results revealed that the blend nanofiber scaffolds showed much higher degradation rates than the neat PHB. The cytocompatibility of the blend nanofiber scaffolds was preliminarily evaluated by cell adhesion studies. The cells incubated with PHB/CA blend nanofiber scaffold for 48 h were capable of forming cell adhesion and proliferation. It showed much better biocompatibility than pure PHB film. Thus, the prepared PHB/CA blend nanofiber scaffolds are bioactive and may be more suitable for cell proliferation suggesting that these scaffolds can be used for

  14. In Vitro Assessment of Antibacterial Activity and Cytocompatibility of Quercetin-Containing PLGA Nanofibrous Scaffolds for Tissue Engineering

    Directory of Open Access Journals (Sweden)

    Zhi-Cai Xing

    2012-01-01

    Full Text Available Flavonoids, such as quercetin, have been reported to exhibit a wide range of biological activities related to their antioxidant capacity. The aim of this study was to investigate the protective effect of quercetin on cell adhesion, and the viability and proliferation of KB epithelial cells. Quercetin- (1, 5 wt%-containing poly (l-lactide-co-glycolide (PLGA nanofibrous scaffolds (PLGA/Q 1, PLGA/Q 5 were prepared by electrospinning technique and their antibacterial properties were examined. Two types of bacteria strains, Staphylococcus aureus (SA and Klebsiella pneumoniae (KP, were used to evaluate the antibacterial properties of the scaffolds. The results showed that the quercetin-containing PLGA nanofibrous scaffolds exhibited significant antibacterial effects against the two bacterial strains. KB epithelial cells were also used to evaluate the cytocompatibility of the scaffolds. From the results, it was found that the PLGA nanofibrous scaffolds with 1 wt% of quercetin had good cell compatibility. It is considered that the PLGA nanofibrous scaffolds with 1 wt% quercetin have potential to be used in tissue engineering.

  15. Oxygen plasma surface modification augments poly(L-lactide-co-glycolide) cytocompatibility toward osteoblasts and minimizes immune activation of macrophages.

    Science.gov (United States)

    Scislowska-Czarnecka, Anna; Szmigiel, Dariusz; Genet, Michel; Dupont-Gillain, Christine; Pamula, Elzbieta; Kolaczkowska, Elzbieta

    2015-12-01

    Here, we report on modification of one of the model biomedical polymers, poly L-lactide-co-glycolide (PLGA; 85:15), by reactive ion etching (RIE) oxygen plasma treatment. PLGA's major disadvantage is high hydrophobicity which restrains binding of cell-adhesive proteins and host cells. In the current approach, we aimed to answer two questions: (1) will only short (10 s) and moderate (20-200 mTorr, 45-90 W) RIE oxygen plasma treatment, leading to decrease of water contact angle by only up to 10°, sufficiently improve PLGA adherence to cells, and (2) how will this affect osteoblasts and activation of the immune system? All obtained modified PLGAs had improved hydrophilicity but unaltered roughness (as revealed by water contact angle measurements, X-ray photoelectron spectroscopy, and atomic force microscopy) resulting in significantly improved adhesion of osteoblasts (MG-63) and their low activation. Importantly, macrophages (RAW 264.7), one of the key cells initiating inflammation and bone resorption, responded significantly less vigorously to the modified polymers, expressing/releasing lower amounts of nitric oxide, matrix metalloproteinases (MMP-9), and pro-inflammatory cytokines (TNF-α, IL-6, IL-12p70, IFN-γ, IL-10). We conclude that already slight RIE oxygen plasma modification of PLGA is sufficient to improve its surface properties, and enhance cytocompatibility. Most importantly, this type of modification prevents excessive immune response. PMID:26014580

  16. In Vitro Assessment of Antibacterial Activity and Cytocompatibility of Quercetin-Containing PLGA Nano fibrous Scaffolds for Tissue Engineering

    International Nuclear Information System (INIS)

    Flavonoids, such as quercetin, have been reported to exhibit a wide range of biological activities related to their antioxidant capacity. The aim of this study was to investigate the protective effect of quercetin on cell adhesion, and the viability and proliferation of KB epithelial cells. Quercetin- (1, 5 wt%)-containing poly (l-lactide-co-glycolide) (PLGA) nano fibrous scaffolds (PLGA/Q 1, PLGA/Q 5) were prepared by electro spinning technique and their antibacterial properties were examined. Two types of bacteria strains, Staphylococcus aureus (SA) and Klebsiella pneumoniae (KP), were used to evaluate the antibacterial properties of the scaffolds. The results showed that the quercetin-containing PLGA nano fibrous scaffolds exhibited significant antibacterial effects against the two bacterial strains. KB epithelial cells were also used to evaluate the cytocompatibility of the scaffolds. From the results, it was found that the PLGA nano fibrous scaffolds with 1 wt% of quercetin had good cell compatibility. It is considered that the PLGA nano fibrous scaffolds with 1 wt% quercetin have potential to be used in tissue engineering.

  17. Improvement of bioactivity, degradability, and cytocompatibility of biocement by addition of mesoporous magnesium silicate into sodium-magnesium phosphate cement.

    Science.gov (United States)

    Wu, Yingyang; Tang, Xiaofeng; Chen, Jie; Tang, Tingting; Guo, Han; Tang, Songchao; Zhao, Liming; Ma, Xuhui; Hong, Hua; Wei, Jie

    2015-09-01

    A novel mesoporous magnesium-based cement (MBC) was fabricated by using the mixed powders of magnesium oxide, sodium dihydrogen phosphate, and mesoporous magnesium silicate (m-MS). The results indicate that the setting time and water absorption of the MBC increased as a function of increasing m-MS content, while compressive strength decreased. In addition, the degradability of the MBC in a solution of Tris-HCl and the ability of apatite formation on the MBC were significantly improved with the increase in m-MS content. In cell culture experiments, the results show that the attachment, proliferation, and alkaline phosphatase activity of the MC3T3-E1 cells on the MBC were significantly enhanced with the increase of the content of m-MS. It can be suggested that the MBC with good cytocompatibility could promote the proliferation and differentiation of the MC3T3-E1 cells. In short, our findings indicate that the MBC containing m-MS had promising potential as a new biocement for bone regeneration and repair applications. PMID:26395363

  18. Engineered Hybrid Scaffolds of Poly(vinyl alcohol/Bioactive Glass for Potential Bone Engineering Applications: Synthesis, Characterization, Cytocompatibility, and Degradation

    Directory of Open Access Journals (Sweden)

    Hermes S. Costa

    2012-01-01

    Full Text Available The synthesis, characterization, preliminary cytocompatibility, and degradation behavior of the hybrids based on 70% Poly(vinyl alcohol and 30% bioactive glass (58SiO2–33CaO–9P2O5, BaG with macroporous tridimensional structure is reported for the first time. The effect of glutaraldehyde covalent crosslinker in the organic-inorganic nanostructures produced and, as a consequence, tailoring the hybrids properties was investigated. The PVA/BaG hybrids scaffolds are characterized by Fourier transform infrared spectroscopy (FTIR, scanning electron microscopy (SEM, X-ray diffraction (XRD, and X-ray Microcomputed tomography analysis (μCT. Cytotoxicity assessment is performed by the MTT method with VERO cell culture. Additionally, the hybrid in vitro degradation assay is conducted by measuring the mass loss by soaking in deionized water at 37°C for up to 21 days. The results have clearly shown that it is possible to modify the PVA/BaG hybrids properties and degradation behavior by engineering the structure using different concentrations of the chemical crosslinker. Moreover, these hybrid crosslinked nanostructures have presented 3D hierarchical pore size architecture varying within 10–450 μm and a suitable cytocompatibility for potential use in bone tissue engineering applications.

  19. Enzymatic degradation behavior and cytocompatibility of silk fibroin–starch–chitosan conjugate membranes

    OpenAIRE

    Baran, E. T.; Tuzlakoglu, K.; Mano, J. F.; Reis, R. L.

    2012-01-01

    The objective of this study was to investigate the influence of silk fibroin and oxidized starch conjugation on the enzymatic degradation behavior and the cytocompatability of chitosan based biomaterials. The tensile stress of conjugate membranes, which was at 50 Megapascal (MPa) for the lowest fibroin and starch composition (10 weight percent (wt.%)), was decreased significantly with the increased content of fibroin and starch. The weight loss of conjugates in α-amylase was more ...

  20. Screening on binary Zr-1X (X = Ti, Nb, Mo, Cu, Au, Pd, Ag, Ru, Hf and Bi) alloys with good in vitro cytocompatibility and magnetic resonance imaging compatibility.

    Science.gov (United States)

    Zhou, F Y; Qiu, K J; Li, H F; Huang, T; Wang, B L; Li, L; Zheng, Y F

    2013-12-01

    In this study, the microstructures, mechanical properties, corrosion behaviors, in vitro cytocompatibility and magnetic susceptibility of Zr-1X alloys with various alloying elements, including Ti, Nb, Mo, Cu, Au, Pd, Ag, Ru, Hf and Bi, were systematically investigated to explore their potential use in biomedical applications. The experimental results indicated that annealed Zr-1X alloys consisted entirely or primarily of α phase. The alloying elements significantly increased the strength and hardness of pure Zr and had a relatively slight influence on elastic modulus. Ru was the most effective enhancing element and Zr-1Ru alloy had the largest elongation. The results of electrochemical corrosion indicated that adding various elements to Zr improved its corrosion resistance, as indicated by the reduced corrosion current density. The extracts of the studied Zr-1X alloys produced no significant deleterious effects on osteoblast-like cells (MG 63), indicating good in vitro cytocompatibility. All except for Zr-1Ag alloy showed decreased magnetic susceptibility compared to pure Zr, and Zr-1Ru alloy had the lowest magnetic susceptibility value, being comparable to that of α' phase Zr-Mo alloy and Zr-Nb alloy and far lower than that of Co-Cr alloy and Ti-6Al-4V alloy. Among the experimental Zr-1X alloys, Zr-1Ru alloy possessing high strength coupled with good ductility, good in vitro cytocompatibility and low magnetic susceptibility may be a good candidate alloy for medical devices within a magnetic resonance imaging environment. PMID:23928334

  1. Electrospun composite nanofiber membrane of poly(l-lactide) and surface grafted chitin whiskers: Fabrication, mechanical properties and cytocompatibility.

    Science.gov (United States)

    Liu, Hua; Liu, Wenjun; Luo, Binghong; Wen, Wei; Liu, Mingxian; Wang, Xiaoying; Zhou, Changren

    2016-08-20

    To improve both the mechanical properties and cytocompatibility of poly(l-lactide) (PLLA), rod-like chitin whiskers (CHWs) were prepared, and subsequently surface modified with l-lactide to obtain grafted CHWs (g-CHWs). Then, CHWs and g-CHWs were further introduced into PLLA matrix to fabricate CHWs/PLLA and g-CHWs/PLLA nanofiber membranes by electrospinning technique. Morphologies and properties of the CHWs and g-CHWs were characterized. The surface-grafted PLLA chains played an important role in improving interfacial interaction between the whiskers and PLLA matrix. The g-CHWs dispersed more uniformly in matrix than CHWs, and the as-prepared g-CHWs/PLLA nanofiber membrane showed relative smooth and uniform fiber. As a result, the tensile strength and modulus of the g-CHWs/PLLA nanofiber membrane were obviously superior to those of the pure PLLA and CHWs/PLLA nanofiber membranes. Cells culture results indicated that g-CHWs/PLLA nanofiber membrane is more effectively in promoting MC3T3-E1 cells adhesion, spreading and proliferation than pure PLLA and CHWs/PLLA nanofiber membrane. PMID:27178927

  2. Nanostructured titanium-silver coatings with good antibacterial activity and cytocompatibility fabricated by one-step magnetron sputtering

    Science.gov (United States)

    Bai, Long; Hang, Ruiqiang; Gao, Ang; Zhang, Xiangyu; Huang, Xiaobo; Wang, Yueyue; Tang, Bin; Zhao, Lingzhou; Chu, Paul K.

    2015-11-01

    Bacterial infection and loosing are serious complications for biomedical implants in the orthopedic, dental, and other biomedical fields and the ideal implants should combine good antibacterial ability and bioactivity. In this study, nanostructured titanium-silver (Ti-Ag) coatings with different Ag contents (1.2 to 21.6 at%) are prepared on Ti substrates by magnetron sputtering. As the Ag concentration is increased, the coatings change from having dense columnar crystals to sparse ones and eventually no columnar structure. The Ti-Ag coatings can effectively kill Staphylococcus aureus during the first few days and remain moderately antibacterial after immersion for 75 days. Compared to pure Ti, the Ti-Ag coatings show good cytocompatibility as indicated by good osteoblast adhesion, proliferation, intracellular total protein synthesis, and alkaline phosphatase (ALP) activity. In addition, cell spreading, collagen secretion, and extracellular matrix mineralization are promoted on the coatings with the proper Ag contents due to the nanostructured morphological features. Our results indicate that favorable antibacterial activity and osseointegration ability can be simultaneously achieved by regulating the Ag contents in Ti-Ag coatings.

  3. Application of 1H and 23Na magic angle spinning NMR spectroscopy to define the HRBC up-taking of MRI contrast agents

    Science.gov (United States)

    Calabi, Luisella; Paleari, Lino; Biondi, Luca; Linati, Laura; De Miranda, Mario; Ghelli, Stefano

    2003-09-01

    The up-take of Gd(III) complexes of BOPTA, DTPA, DOTA, EDTP, HPDO3A, and DOTP in HRBC has been evaluated by measuring the lanthanide induced shift (LIS) produced by the corresponding dysprosium complexes (DC) on the MAS-NMR resonances of water protons and free sodium ions. These complexes are important in their use as MRI contrast agents (MRI-CA) in diagnostics. 1H and 23Na MAS-NMR spectra of HRBC suspension, collected at 9.395 T, show only one signal due to extra- and intra-cellular water (or sodium). In MAS spectra, the presence of DC in a cellular compartment produces the LIS of only the nuclei (water proton or sodium) in that cellular compartment and this LIS can be related to the DC concentrations (by the experimental curves of LIS vs. DC concentrations) collected in the physiological solution. To obtain correct results about LIS, the use of MAS technique is mandatory, because it guarantees the only the nuclei staying in the same cellular compartment where the LC is present show the LIS. In all the cases considered, the addition of the DC to HRBC (100% hematocrit) produced a shift of only the extra-cellular water (or sodium) signal and the gradient of concentration ( GC) between extra- and intra-cellular compartments resulted greater than 100:1, when calculated by means of sodium signals. These high values of GC are direct proofs that none of the tested dysprosium complexes crosses the HRBC membrane. Since the DC are iso-structural to the gadolinium complexes the corresponding gadolinium ones (MRI-CA) do not cross the HRBC membrane and, consequently, they are not up-taken in HRBC. The GC values calculated by means of water proton signals resulted much lower than those obtained by sodium signals. This proves that the choice of the isotope is a crucial step in order to use this method in the best way. In fact, GC value depends on the lowest detectable LIS which, in turn, depends on the nature of the LC (lanthanide complex) and the observed isotopes.

  4. Cytocompatible antifungal acrylic resin containing silver nanoparticles for dentures

    Directory of Open Access Journals (Sweden)

    Acosta-Torres LS

    2012-09-01

    Full Text Available Laura Susana Acosta-Torres,1 Irasema Mendieta,2 Rosa Elvira Nuñez-Anita,3 Marcos Cajero-Juárez,3 Víctor M Castaño41National School of Higher Education, School of Dentistry - Leon Unit, National Autonomus University of Mexico (UNAM, Leon, Guanajuato, 2Neurobiology Institute, National Autonomus University of Mexico (UNAM, Juriquilla, Queretaro, 3Animal Biotechnology Laboratory, Faculty of Veterinary Medicine at San Nicolas de Hidalgo, Michoacán University, Michoacán, 4Molecular Materials Department, Applied Physics and Advanced Technology Center, National Autonomus University of Mexico (UNAM, Juriquilla, Queretaro, MexicoBackground: Inhibition of Candida albicans on denture resins could play a significant role in preventing the development of denture stomatitis. The safety of a new dental material with antifungal properties was analyzed in this work.Methods: Poly(methyl methacrylate [PMMA] discs and PMMA-silver nanoparticle discs were formulated, with the commercial acrylic resin, Nature-CrylTM, used as a control. Silver nanoparticles were synthesized and characterized by ultraviolet-visible spectroscopy, dispersive Raman spectroscopy, and transmission electron microscopy. The antifungal effect was assessed using a luminescent microbial cell viability assay. Biocompatibility tests were carried out using NIH-3T3 mouse embryonic fibroblasts and a Jurkat human lymphocyte cell line. Cells were cultured for 24 or 72 hours in the presence or absence of the polymer formulations and analyzed using three different tests, ie, cellular viability by 3-(4,5-dimethylthiazol-2-yl-2,5-diphenyltetrazolium bromide (MTT assay, and cell proliferation by enzyme-linked immunosorbent assay BrdU, and genomic DNA damage (Comet assay. Finally, the samples were evaluated mechanically, and the polymer-bearing silver nanoparticles were analyzed microscopically to evaluate dispersion of the nanoparticles.Results: The results show that PMMA-silver nanoparticle discs

  5. The cytocompatability of polyhydroxyalkanoates coated with a fusion protein of PHA repressor protein (PhaR) and Lys-Gln-Ala-Gly-Asp-Val (KQAGDV) polypeptide.

    Science.gov (United States)

    Dong, Cui-Ling; Li, Shi-Yan; Wang, Yang; Dong, Ying; Tang, James Zhenggui; Chen, Jin-Chun; Chen, Guo-Qiang

    2012-03-01

    Microbial polyhydroxyalkanoates (PHAs) are a family of polyesters with biodegradability, biocompatibility and adjustable mechanical properties that are under intensive development for bioimplant applications. In this research, a fusion protein of PHA repressor protein (PhaR) and Lys-Gln-Ala-Gly-Asp-Val (KQAGDV) oligopeptide (PhaR-KQAGDV) was utilized to enhance the PHA cytocompatability via a mechanism of PhaR hydrophobically binding to PHA coupled with KQAGDV oligopeptide, a specific ligand to the integrins on the cell surface, for promotion of cell adhesion. The PhaR-KQAGDV fusion protein successfully produced and purified from recombinant E. coli was used to coat the surfaces of several PHA including poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV), poly(3-hydroxybutyrate-co-4-hydroxybutyrate) (P3HB4HB) and poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHBHHx), respectively. The PhaR was observed to bind efficiently on all PHA surfaces measured by the fluorescence intensity of PhaR-EGFP as compared to the uncoated (PhaR negative) PHA films. The PHA surface hydrophilicity measured by water contact angles was significantly improved after PhaR-KQAGDV coating. Observations under confocal microscope and scanning electron microscopy, together with CCK-8 assays clearly demonstrated that adhesion and proliferation of human vascular smooth muscle cells (HvSMCs) inoculated on PHA films were much better on PhaR-KQAGDV coated surfaces than the non-coated control ones. The convenient physical coating approach for enhanced PHA cytocompatibility provides an advantage for PHA based tissue engineering. PMID:22206593

  6. Cytocompatibility and early osseointegration of nanoTiO{sub 2}-modified Ti-24 Nb-4 Zr-7.9 Sn surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Liu, X.H. [Department of Prosthodontics, China Medical University School of Stomatology, Shenyang (China); Wu, L., E-mail: wulin13@163.com [Department of Prosthodontics, China Medical University School of Stomatology, Shenyang (China); Ai, H.J. [Department of Prosthodontics, China Medical University School of Stomatology, Shenyang (China); Han, Y. [State Key laboratory for Mechanical Behaviour of Materials, Xi' an Jiaotong University, Xi' an (China); Hu, Y. [Department of Prosthodontics, China Medical University School of Stomatology, Shenyang (China)

    2015-03-01

    This study aimed to evaluate the cytocompatibility and early osseointegration of Ti-24 Nb-4 Zr-7.9 Sn (Ti-2448) surfaces that were modified with a nanoscale TiO{sub 2} coating. The coating was fabricated using a hydrothermal synthesis method to generate nanoTiO{sub 2}/Ti-2448. The surface characteristics of the samples were evaluated using scanning electron microscopy (SEM), energy dispersive spectrometry (EDS) and X-ray diffraction (XRD). The cytotoxicity of the fabricated nanoTiO{sub 2}/Ti-2448 was determined using MTT assays. The proliferation and alkaline phosphatase (ALP) activity of MC3T3-E1 osteoblasts cultured on nanoTiO{sub 2}/Ti-2448 were compared with those cultured on Ti-2448. Disk-shaped implants were placed in Wistar rats. The histological sections were stained with haematoxylin and eosin (HE), and the histocompatibility was analysed at 4 and 12 weeks post-implantation. Cylindrical implants were embedded in Japanese white rabbits, and the histological sections were stained with HE and anti-TGF-β1 to evaluate the histocompatibility and early osseointegration at 4, 12 and 26 weeks post-implantation. NanoTiO{sub 2}/Ti-2448 exhibited a rougher surface than did Ti-2448. NanoTiO{sub 2}/Ti-2448 was determined to be non-cytotoxic. More osteoblasts and higher ALP activity were observed for nanoTiO{sub 2}/Ti-2448 than Ti-2448 (p < 0.05). Few inflammatory cells were detected around nanoTiO{sub 2}/Ti-2448, and the expression of TGF-β1 on nanoTiO{sub 2}/Ti-2448 peaked at earlier time than that on Ti-2448. The results indicate that the cytocompatibility and early osseointegration were enhanced by the nanoTiO{sub 2} coating. - Highlights: • The cytocompatibility of nanoTiO2/Ti-2448 is first reported in our work. • The early osseointegration of nanoTiO2/Ti-2448 is first reported in our work. • We evaluate the biocompatibility of nanoTiO2/Ti-2448 by in-vitro and in-vivo tests.

  7. Cytocompatibility and early osseointegration of nanoTiO2-modified Ti-24 Nb-4 Zr-7.9 Sn surfaces

    International Nuclear Information System (INIS)

    This study aimed to evaluate the cytocompatibility and early osseointegration of Ti-24 Nb-4 Zr-7.9 Sn (Ti-2448) surfaces that were modified with a nanoscale TiO2 coating. The coating was fabricated using a hydrothermal synthesis method to generate nanoTiO2/Ti-2448. The surface characteristics of the samples were evaluated using scanning electron microscopy (SEM), energy dispersive spectrometry (EDS) and X-ray diffraction (XRD). The cytotoxicity of the fabricated nanoTiO2/Ti-2448 was determined using MTT assays. The proliferation and alkaline phosphatase (ALP) activity of MC3T3-E1 osteoblasts cultured on nanoTiO2/Ti-2448 were compared with those cultured on Ti-2448. Disk-shaped implants were placed in Wistar rats. The histological sections were stained with haematoxylin and eosin (HE), and the histocompatibility was analysed at 4 and 12 weeks post-implantation. Cylindrical implants were embedded in Japanese white rabbits, and the histological sections were stained with HE and anti-TGF-β1 to evaluate the histocompatibility and early osseointegration at 4, 12 and 26 weeks post-implantation. NanoTiO2/Ti-2448 exhibited a rougher surface than did Ti-2448. NanoTiO2/Ti-2448 was determined to be non-cytotoxic. More osteoblasts and higher ALP activity were observed for nanoTiO2/Ti-2448 than Ti-2448 (p < 0.05). Few inflammatory cells were detected around nanoTiO2/Ti-2448, and the expression of TGF-β1 on nanoTiO2/Ti-2448 peaked at earlier time than that on Ti-2448. The results indicate that the cytocompatibility and early osseointegration were enhanced by the nanoTiO2 coating. - Highlights: • The cytocompatibility of nanoTiO2/Ti-2448 is first reported in our work. • The early osseointegration of nanoTiO2/Ti-2448 is first reported in our work. • We evaluate the biocompatibility of nanoTiO2/Ti-2448 by in-vitro and in-vivo tests

  8. Cytocompatibility of chitosan and collagen-chitosan scaffolds for tissue engineering

    Directory of Open Access Journals (Sweden)

    Ligia L. Fernandes

    2011-01-01

    Full Text Available In this work, chitosan and collagen-chitosan porous scaffolds were produced by the freeze drying method and characterized as potential skin substitutes. Their beneficial effects on soft tissues justify the choice of both collagen and chitosan. Samples were characterized using scanning electron microscope, Fourier Transform InfraRed Spectroscopy (FTIR and thermogravimetry (TG. The in vitro cytocompatibility of chitosan and collagen-chitosan scaffolds was evaluated with three different assays. Phenol and titanium powder were used as positive and negative controls, respectively. Scanning electron microscopy revealed the highly interconnected porous structure of the scaffolds. The addition of collagen to chitosan increased both pore diameter and porosity of the scaffolds. Results of FTIR and TG analysis indicate that the two polymers interact yielding a miscible blend with intermediate thermal degradation properties. The reduction of XTT ((2,3-bis[2-methyloxy-4-nitro-5-sulfophenyl]-2H-tetrazolium-5-carboxanilide and the uptake of Neutral Red (NR were not affected by the blend or by the chitosan scaffold extracts, but the blend and the titanium powder presented greater incorporation of Crystal Violet (CV than phenol and chitosan alone. In conclusion, collagen-chitosan scaffolds produced by freeze-drying methods were cytocompatible and presented mixed properties of each component with intermediate thermal degradation properties.

  9. Cytocompatibility and early osseointegration of nanoTiO2-modified Ti-24 Nb-4 Zr-7.9 Sn surfaces.

    Science.gov (United States)

    Liu, X H; Wu, L; Ai, H J; Han, Y; Hu, Y

    2015-03-01

    This study aimed to evaluate the cytocompatibility and early osseointegration of Ti-24 Nb-4 Zr-7.9 Sn (Ti-2448) surfaces that were modified with a nanoscale TiO2 coating. The coating was fabricated using a hydrothermal synthesis method to generate nanoTiO2/Ti-2448. The surface characteristics of the samples were evaluated using scanning electron microscopy (SEM), energy dispersive spectrometry (EDS) and X-ray diffraction (XRD). The cytotoxicity of the fabricated nanoTiO2/Ti-2448 was determined using MTT assays. The proliferation and alkaline phosphatase (ALP) activity of MC3T3-E1 osteoblasts cultured on nanoTiO2/Ti-2448 were compared with those cultured on Ti-2448. Disk-shaped implants were placed in Wistar rats. The histological sections were stained with haematoxylin and eosin (HE), and the histocompatibility was analysed at 4 and 12weeks post-implantation. Cylindrical implants were embedded in Japanese white rabbits, and the histological sections were stained with HE and anti-TGF-β1 to evaluate the histocompatibility and early osseointegration at 4, 12 and 26weeks post-implantation. NanoTiO2/Ti-2448 exhibited a rougher surface than did Ti-2448. NanoTiO2/Ti-2448 was determined to be non-cytotoxic. More osteoblasts and higher ALP activity were observed for nanoTiO2/Ti-2448 than Ti-2448 (p<0.05). Few inflammatory cells were detected around nanoTiO2/Ti-2448, and the expression of TGF-β1 on nanoTiO2/Ti-2448 peaked at earlier time than that on Ti-2448. The results indicate that the cytocompatibility and early osseointegration were enhanced by the nanoTiO2 coating. PMID:25579921

  10. Electroactive polyurethane/siloxane derived from castor oil as a versatile cardiac patch, part II: HL-1 cytocompatibility and electrical characterizations.

    Science.gov (United States)

    Baheiraei, Nafiseh; Gharibi, Reza; Yeganeh, Hamid; Miragoli, Michele; Salvarani, Nicolò; Di Pasquale, Elisa; Condorelli, Gianluigi

    2016-06-01

    In first part of this experiment, biocompatibility of the newly developed electroactive polyurethane/siloxane films containing aniline tetramer moieties was demonstrated with proliferation and differentiation of C2C12 myoblasts. Here we further assessed the cytocompatibility of the prepared samples with HL1-cell line, the electrophysiological properties and the patch clamp recording of the seeded cells over the selected electroactive sample. Presence of electroactive aniline tetramer in the structure of polyurethane/siloxane led to the increased expression of cardiac-specific genes of HL-1 cells involved in muscle contraction and electrical coupling. Our results showed that expression of Cx43, TrpT-2, and SERCA genes was significantly increased in conductive sample compared to tissue culture plate and the corresponding non-conductive analogous. The prepared materials were not only biocompatible in terms of cellular toxicity, but did not alter the intrinsic electrical characteristics of HL-1 cells. Embedding the electroactive moiety into the prepared films improved the properties of these polymeric cardiac construct through the enhanced transmission of electrical signals between the cells. Based on morphological observation, calcium imaging and electrophysiological recordings, we demonstrated the potential applicability of these materials for cardiac tissue engineering. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 104A: 1398-1407, 2016. PMID:26822463

  11. A new quantitative test method for cell proliferation based on detection of the Ki-67 protein

    NARCIS (Netherlands)

    Klein, CL; Wagner, M; Kirkpatrick, CJ; Van Kooten, TG

    1999-01-01

    A quantitative method to assess cell proliferation is one essential prerequisite for testing biomaterial cytocompatibility in vitro. Currently used methods, e.g. bromodeoxyuridine incorporation, show serious disadvantages concerning either sensitivity, specificity or handling. A new enzyme linked im

  12. Fabrication, properties, and cytocompatibility of ZrC film on electropolished NiTi shape memory alloy

    International Nuclear Information System (INIS)

    The microstructural characteristics, mechanical properties, and cytocompatibility of ZrC films deposited on electropolished NiTi shape memory alloy (SMA) by magnetron sputtering are investigated by scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), nanoindentation, and MTT test. The deposition rate of the ZrC film is smaller than the pure Zr film. Although ZrC is the only phase in the film, the pure ZrC film with small oxygen content is non-stoichiometric. The hardness and modulus increase initially with larger nanoindentation depths, reach maximum values, and then gradually decrease afterwards as a result of the composite effects of the ZrC film and NiTi substrate. Deposition of the ZrC film promotes proliferation of fibroblasts revealing enhanced cytocompatibility compared to uncoated NiTi.

  13. Blood-Vessel Mimicking Structures by Stereolithographic Fabrication of Small Porous Tubes Using Cytocompatible Polyacrylate Elastomers, Biofunctionalization and Endothelialization

    OpenAIRE

    Birgit Huber; Sascha Engelhardt; Wolfdietrich Meyer; Hartmut Krüger; Annika Wenz; Veronika Schönhaar; Tovar, Günter E. M.; Kluger, Petra J.; Kirsten Borchers

    2016-01-01

    Blood vessel reconstruction is still an elusive goal for the development of in vitro models as well as artificial vascular grafts. In this study, we used a novel photo-curable cytocompatible polyacrylate material (PA) for freeform generation of synthetic vessels. We applied stereolithography for the fabrication of arbitrary 3D tubular structures with total dimensions in the centimeter range, 300 µm wall thickness, inner diameters of 1 to 2 mm and defined pores with a constant diameter of appr...

  14. A novel injectable thermoresponsive and cytocompatible gel of poly(N-isopropylacrylamide) with layered double hydroxides facilitates siRNA delivery into chondrocytes in 3D culture.

    Science.gov (United States)

    Yang, Hsiao-yin; van Ee, Renz J; Timmer, Klaas; Craenmehr, Eric G M; Huang, Julie H; Öner, F Cumhur; Dhert, Wouter J A; Kragten, Angela H M; Willems, Nicole; Grinwis, Guy C M; Tryfonidou, Marianna A; Papen-Botterhuis, Nicole E; Creemers, Laura B

    2015-09-01

    Hybrid hydrogels composed of poly(N-isopropylacrylamide) (pNIPAAM) and layered double hydroxides (LDHs) are presented in this study as novel injectable and thermoresponsive materials for siRNA delivery, which could specifically target several negative regulators of tissue homeostasis in cartilaginous tissues. Effectiveness of siRNA transfection using pNIPAAM formulated with either MgAl-LDH or MgFe-LDH platelets was investigated using osteoarthritic chondrocytes. Glyceraldehyde-3-phosphate dehydrogenase (GAPDH) was used as an endogenous model gene to evaluate the extent of silencing. No significant adverse effects of pNIPAAM/LDH hydrogels on cell viability were noticed. Cellular uptake of fluorescently labeled siRNA was greatly enhanced (>75%) in pNIPAAM/LDH hydrogel constructs compared to alginate, hyaluronan and fibrin gels, and was absent in pNIPAAM hydrogel without LDH platelets. When using siRNA against GAPDH, 82-98% reduction of gene expression was found in both types of pNIPAAM/LDH hydrogel constructs after 6 days of culturing. In the pNIPAAM/MgAl-LDH hybrid hydrogel, 80-95% of GAPDH enzyme activity was reduced in parallel with gene. Our findings show that the combination of a cytocompatible hydrogel and therapeutic RNA oligonucleotides is feasible. Thus it might hold promise in treating degeneration of cartilaginous tissues by providing supporting scaffolds for cells and interference with locally produced degenerative factors. PMID:26022968

  15. Enhanced mechanical properties and cytocompatibility of electrospun poly(L-lactide) composite fiber membranes assisted by polydopamine-coated halloysite nanotubes

    Science.gov (United States)

    Luo, Chuang; Zou, Ziping; Luo, Binghong; Wen, Wei; Li, Huihua; Liu, Mingxian; Zhou, Changren

    2016-04-01

    To improve the dispersion and interfacial interaction between halloysite nanotubes (HNTs) and poly(L-lactide) (PLLA) matrix, and hence to increase the mechanical properties and cytocompatibility of the HNTs/PLLA composite, a facile approach was developed to prepare polydopamine-coated HNTs (D-HNTs) by the self-polymerization of dopamine (DOPA), and then HNTs and D-HNTs were further introduced into PLLA matrix to fabricate HNTs/PLLA and D-HNTs/PLLA fiber membranes based on electrospinning technique. The successful immobilization of the polydopamine (PDOPA) coating on the surfaces of HNTs was confirmed, and such PDOPA coating played an important role in improving the interfacial interaction between the nanotubes and PLLA matrix. The D-HNTs were dispersed in the matrix more uniformly than untreated HNTs, and relative smooth and uniform fiber were obtained for the D-HNTs/PLLA fiber membrane. As a result, the tensile strength and modulus of the D-HNTs/PLLA fiber membrane were obviously superior to those of the HNTs/PLLA fiber membrane. Cell culture results revealed that D-HNTs/PLLA fiber membrane was more effectively to promote MC3T3-E1 cells adhesion and proliferation than neat PLLA and HNTs/PLLA fiber membrane.

  16. Preparation, characterization and cytocompatibility of bioactive coatings on porous calcium-silicate-hydrate scaffolds

    International Nuclear Information System (INIS)

    The major goal of this research was to investigate and characterize the deposition of a biomimetic apatite-like coating onto the surface of 3D porous calcium-silicate-hydrate scaffolds with suitable bioactivity for potential application in bone tissue engineering. Basically, Portland cement, water, sand and lime were mixed for preparing the slurry which was poured into molds, and fine aluminum powder was added as foaming agent resulting on the formation of porous 3D structures. After aging for 28 days, these porous inorganic scaffolds were immersed in calcium chloride supersaturated solution in PBS for 7 days at 37 deg. C for the biomimetic layer deposition. Scanning electron microscopy (SEM), X-ray diffraction (XRD) and Fourier Transformed Infrared Spectroscopy (FTIR) techniques were used in order to characterize the porous scaffolds and the apatite-like biomimetic coating. The results have showed that 3D constructs were successfully produced with interconnected porosity, compressive strength and cytocompatibility appropriate for potential use as an alternative in trabecular bone repair.

  17. Nanocoating of single cells: from maintenance of cell viability to manipulation of cellular activities.

    Science.gov (United States)

    Park, Ji Hun; Yang, Sung Ho; Lee, Juno; Ko, Eun Hyea; Hong, Daewha; Choi, Insung S

    2014-04-01

    The chronological progresses in single-cell nanocoating are described. The historical developments in the field are divided into biotemplating, cytocompatible nanocoating, and cells in nano-nutshells, depending on the main research focuses. Each subfield is discussed in conjunction with the others, regarding how and why to manipulate living cells by nanocoating at the single-cell level. PMID:24452932

  18. In Vitro Corrosion and Cytocompatibility of a Microarc Oxidation Coating and Poly(l-lactic acid) Composite Coating on Mg-1Li-1Ca Alloy for Orthopedic Implants.

    Science.gov (United States)

    Zeng, Rong-Chang; Cui, Lan-Yue; Jiang, Ke; Liu, Rui; Zhao, Bao-Dong; Zheng, Yu-Feng

    2016-04-20

    Manipulating the degradation rate of biomedical magnesium alloys poses a challenge. The characteristics of a microarc oxidation (MAO), prepared in phytic acid, and poly(l-lactic acid) (PLLA) composite coating, fabricated on a novel Mg-1Li-1Ca alloy, were studied through field emission scanning electron microscopy (FE-SEM), electron probe X-ray microanalysis (EPMA), energy dispersive X-ray spectroscopy (EDS) and X-ray diffraction (XRD). The corrosion behaviors of the samples were evaluated via hydrogen evolution, potentiodynamic polarization and electrochemical impedance spectroscopy in Hanks' solution. The results indicated that the MAO/PLLA composite coatings significantly enhanced the corrosion resistance of the Mg-1Li-1Ca alloy. MTT and ALP assays using MC3T3 osteoblasts indicated that the MAO/PLLA coatings greatly improved the cytocompatibility, and the morphology of the cells cultured on different samples exhibited good adhesion. Hemolysis tests showed that the composite coatings endowed the Mg-1Li-1Ca alloys with a low hemolysis ratio. The increased solution pH resulting from the corrosion of magnesium could be tailored by the degradation of PLLA. The degradation mechanism of the composite coatings was discussed. The MAO/PLLA composite coating may be appropriate for applications on degradable Mg-based orthopedic implants. PMID:27022831

  19. Cytocompatibility of chitosan -based thermosensitive hydrogel to human periodontal ligament cell

    Institute of Scientific and Technical Information of China (English)

    PAN Jian-feng; Ji Qiu-xia; Lv Bing-hua; Li Chang-chun; Wu Hong; Li Dan-dan; Li-Hui

    2015-01-01

    Objective:To investigate the ef ect of thermosensitive chitosan /β-glycerophosphate (CS /β-GP)hydrogel on proliferation of human periodontal ligament cel s (HPDLCs). Methods:CS /β-GP were prepared into a thermosensitive hydrogel and its three -dimensional structure was observed under electron microscope.HPDLCs harvested and cultured in vitro were co -cultured with the thermosensitive CS /β-GP hydrogel.Growth of the cel s in the hydrogel was observed with HE staining,and the ef ect of the extract on proliferation of HPDLCs was exam-ined by CCK -8 assay.Results:Observations of SEMand HE staining showed that the thermosensitive CS /β-GP hydrogel was large in pore size and appropriate for cel growth.Dif erent levels of CS /α,β-GP extracts could promote proliferation of HPDLCs.Conclusion:Thermosensitive CS /β-GP hydrogel can promote proliferation of HPDLCs and be a good carrier for periodontal tis-sue engineering because of its thermosensitivity.

  20. Cytocompatibility of direct water synthesized cadmium selenide quantum dots in colo-205 cells

    OpenAIRE

    Rodriguez-Torres, Marcos R.; Velez, Christian; Zayas, Beatriz; Rivera, Osvaldo; Arslan, Zikri; Gonzalez-Vega, Maxine N.; Diaz-Diestra, Daysi; Beltran-Huarac, Juan; Morell, Gerardo; Primera-Pedrozo, Oliva M.

    2015-01-01

    Cadmium selenide quantum dots (CdSe QDs), inorganic semiconducting nanocrystals, are alluring increased attraction due to their highly refined chemistry, availability, and super tunable optical properties suitable for many applications in different research areas, such as photovoltaics, light-emitting devices, environmental sciences, and nanomedicine. Specifically, they are being widely used in bio-imaging in contrast to organic dyes due to their high brightness and improved photo-stability, ...

  1. Antimicrobial activity and cytocompatibility of silver nanoparticles coated catheters via a biomimetic surface functionalization strategy

    Directory of Open Access Journals (Sweden)

    Wu K

    2015-12-01

    Full Text Available Ke Wu,1 Yun Yang,2,3 Yanmei Zhang,2,3 Jiexi Deng,1 Changjian Lin2,31Department of Cardiology, The Affiliated Dongnan Hospital of Xiamen University, Zhangzhou, 2Department of Medical Materials, Beijing Medical Implant Engineering Research Center, Beijing Naton Technology Group, Beijing, 3State Key Laboratory of Physical Chemistry of Solid Surfaces, Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, People’s Republic of ChinaAbstract: Catheter-related bloodstream infections are a significant problem in the clinic and may result in a serious infection. Here, we developed a facile and green procedure for buildup of silver nanoparticles (AgNPs on the central venous catheters (CVCs surface. Inspired by mussel adhesive proteins, dopamine was used to form a thin polydopamine layer and induce AgNPs formation without additional reductants or stabilizers. The chemical and physicochemical properties of AgNPs coated CVCs were characterized by scanning electron microscopy, X-ray photoelectron spectroscopy, Raman spectroscopy, and water contact angle. The Staphylococcus aureus culture experiment was used to study the antibacterial properties. The cytocompatibility was assessed by water soluble tetrazolium salts (WST-1 assay, fluorescence staining, and scanning electron microscopy analysis. The results indicated that the CVCs surface was successfully coated with compact AgNPs. AgNPs were significantly well separated and spherical with a size of 30–50 nm. The density of AgNPs could be modulated by the concentration of silver nitrate solution. The antibacterial activity was dependent on the AgNPs dose. The high dose of AgNPs showed excellent antibacterial activity while associated with increased cytotoxicity. The appropriate density of AgNPs coated CVCs could exhibit improved biocompatibility and maintained evident sterilization effect. It is promising to design mussel-inspired silver releasing CVCs with both

  2. Differences in cytocompatibility, dynamics of the oxide layers' formation, and nickel release between superelastic and thermo-activated nickel-titanium archwires.

    Science.gov (United States)

    Čolić, Miodrag; Tomić, Sergej; Rudolf, Rebeka; Marković, Evgenija; Šćepan, Ivana

    2016-08-01

    Superelastic (SE) and thermo-activated (TA) nickel-titanium (NiTi) archwires are used in everyday orthodontic practice, based on their acceptable biocompatibility and well-defined shape memory properties. However, the differences in their surface microstructure and cytotoxicity have not been clearly defined, and the standard cytotoxicity tests are too robust to detect small differences in the cytotoxicity of these alloys, all of which can lead to unexpected adverse reactions in some patients. Therefore, we tested the hypothesis that the differences in manufacture and microstructure of commercially available SE and TA archwires may influence their biocompatibility. The archwires were studied as-received and after conditioning for 24 h or 35 days in a cell culture medium under static conditions. All of the tested archwires, including their conditioned medium (CM), were non-cytotoxic for L929 cells, but Rematitan SE (both as received and conditioned) induced the apoptosis of rat thymocytes in a direct contact. In contrast, TruFlex SE and Equire TA increased the proliferation of thymocytes. The cytotoxic effect of Rematitan SE correlated with the higher release of Ni ions in CM, higher concentration of surface Ni and an increased oxygen layer thickness after the conditioning. In conclusion, the apoptosis assay on rat thymocytes, in contrast to the less sensitive standard assay on L929 cells, revealed that Rematitan SE was less cytocompatible compared to other archwires and the effect was most probably associated with a higher exposition of the cells to Ni on the surface of the archwire, due to the formation of unstable oxide layer. PMID:27364903

  3. Cytocompatibility, mechanical and dissolution properties of high strength boron and iron oxide phosphate glass fibre reinforced bioresorbable composites.

    Science.gov (United States)

    Sharmin, Nusrat; Hasan, Muhammad S; Parsons, Andrew J; Rudd, Chris D; Ahmed, Ifty

    2016-06-01

    In this study, Polylactic acid (PLA)/phosphate glass fibres (PGF) composites were prepared by compression moulding. Fibres produced from phosphate based glasses P2O5-CaO-MgO-Na2O (P45B0), P2O5-CaO-MgO-Na2O-B2O3 (P45B5), P2O5-CaO-MgO-Na2O-Fe2O3 (P45Fe3) and P2O5-CaO-MgO-Na2O-B2O3-Fe2O3 (P45B5Fe3) were used to reinforce the bioresorbable polymer PLA. Fibre mechanical properties and degradation rate were investigated, along with the mechanical properties, degradation and cytocompatibility of the composites. Retention of the mechanical properties of the composites was evaluated during degradation in PBS at 37°C for four weeks. The fibre volume fraction in the composite varied from 19 to 23%. The flexural strength values (ranging from 131 to 184MPa) and modulus values (ranging from 9.95 to 12.29GPa) obtained for the composites matched those of cortical bone. The highest flexural strength (184MPa) and modulus (12.29GPa) were observed for the P45B5Fe3 composite. After 28 days of immersion in PBS at 37°C, ~35% of the strength profile was maintained for P45B0 and P45B5 composites, while for P45Fe3 and P45B5Fe3 composites ~40% of the initial strength was maintained. However, the overall wet mass change of P45Fe3 and P45B5Fe3 remained significantly lower than that of the P45B0 and P45B5 composites. The pH profile also revealed that the P45B0 and P45B5 composites degraded quicker, correlating well with the degradation profile. From SEM analysis, it could be seen that after 28 days of degradation, the fibres in the fractured surface of P45B5Fe3 composites remain fairly intact as compared to the other formulations. The in vitro cell culture studies using MG63 cell lines revealed both P45Fe3 and P45B5Fe3 composites maintained and showed higher cell viability as compared to the P45B0 and P45B5 composites. This was attributed to the slower degradation rate of the fibres in P45Fe3 and P45B5Fe3 composites as compared with the fibres in P45B0 and P45B5 composites. PMID:26745720

  4. Highly luminescent and cytocompatible cationic Ag2S NIR-emitting quantum dots for optical imaging and gene transfection

    OpenAIRE

    Duman, Fatma Demir; Hocaoğlu, İbrahim; Hocaoglu, Ibrahim; Öztürk, Deniz Gülfem; Ozturk, Deniz Gulfem; Gözüaçık, Devrim; Gozuacik, Devrim; Kiraz, Alper; Yağcı Acar, Havva; Yagci Acar, Havva

    2015-01-01

    Nanoscale PAPER Cite this: Nanoscale, 2015, 7, 11352 Received 12th January 2015, Accepted 23rd May 2015 DOI: 10.1039/c5nr00189g www.rsc.org/nanoscale Highly luminescent and cytocompatible cationic Ag2S NIR-emitting quantum dots for optical imaging and gene transfection† Fatma Demir Duman,a Ibrahim Hocaoglu,a Deniz Gulfem Ozturk,b Devrim Gozuacik,b Alper Kiraza,c and Havva Yagci Acar*a,d,e The development of non-toxic theranostic nanoparticles capable of del...

  5. In Vitro Corrosion and Cytocompatibility Properties of Nano-Whisker Hydroxyapatite Coating on Magnesium Alloy for Bone Tissue Engineering Applications

    Science.gov (United States)

    Yang, Huawei; Yan, Xueyu; Ling, Min; Xiong, Zuquan; Ou, Caiwen; Lu, Wei

    2015-01-01

    We report here the successful fabrication of nano-whisker hydroxyapatite (nHA) coatings on Mg alloy by using a simple one-step hydrothermal process in aqueous solution. The nHA coating shows uniform structure and high crystallinity. Results indicate that nHA coating is promising for improving the in vitro corrosion and cytocompatibility properties of Mg-based implants and devices for bone tissue engineering. In addition, the simple hydrothermal deposition method used in the current study is also applicable to substrates with complex shapes or surface geometries. PMID:25789500

  6. In Vitro Corrosion and Cytocompatibility Properties of Nano-Whisker Hydroxyapatite Coating on Magnesium Alloy for Bone Tissue Engineering Applications

    Directory of Open Access Journals (Sweden)

    Huawei Yang

    2015-03-01

    Full Text Available We report here the successful fabrication of nano-whisker hydroxyapatite (nHA coatings on Mg alloy by using a simple one-step hydrothermal process in aqueous solution. The nHA coating shows uniform structure and high crystallinity. Results indicate that nHA coating is promising for improving the in vitro corrosion and cytocompatibility properties of Mg-based implants and devices for bone tissue engineering. In addition, the simple hydrothermal deposition method used in the current study is also applicable to substrates with complex shapes or surface geometries.

  7. The influence of coupling agents on mechanical property retention and long-term cytocompatibility of phosphate glass fibre reinforced PLA composites.

    Science.gov (United States)

    Hasan, M S; Ahmed, I; Parsons, A J; Walker, G S; Scotchford, C A

    2013-12-01

    Completely resorbable composites are an attractive alternative for metallic bone-fracture fixation devices. However, failure of their interfacial integrity within aqueous environments, which can lead to a rapid loss of overall mechanical properties, has been reported in the literature. In this study coupling agents were investigated for phosphate glass fibre reinforced poly(lactic acid) composites. Three coupling agents with varying wettability were employed to improve initial mechanical properties and their retention in vitro via improvement of the interfacial bond between polymer matrix and fibres. Coupling agents were grafted onto the glass fibres by dip-coating in coupling agent solution at optimised concentrations. Three-aminopropyltriethoxy silane and sorbitol ended PLA oligomer treatments improved the initial flexural properties (27% strength with APS and 17% modulus via SPLA treatment) of the composites and 3-aminopropyltriethoxy silane and hexamethylene diisocyanate (HDI) treatments also decreased the loss of flexural strength and modulus during degradation. HDI treated samples retained 57.2% and 64.7% of their initial strength and modulus, respectively compared to control where only 34% of initial strength and 52% of initial modulus was retained after 28 days of degradation in PBS solution. Initial improvements in flexural properties were associated with improved shear bond strength at the interface due to covalent bonding between the glass fibres and polymer matrix provided by the coupling agents. Delay in mechanical property loss with degradation was suggested to be due to the hydrophobicity at the interface, which could have hindered the interfacial integrity loss and consequently loss of mechanical integrity of the composites. All coupling agent treated and control composites were tested for cytocompatibility using a primary human osteoblast cell line. A comparable response to the control, in terms of cell adhesion, proliferation and differentiation

  8. Surface mechanical properties, corrosion resistance, and cytocompatibility of nitrogen plasma-implanted nickel-titanium alloys: a comparative study with commonly used medical grade materials.

    Science.gov (United States)

    Yeung, K W K; Poon, R W Y; Chu, P K; Chung, C Y; Liu, X Y; Lu, W W; Chan, D; Chan, S C W; Luk, K D K; Cheung, K M C

    2007-08-01

    Stainless steel and titanium alloys are the most common metallic orthopedic materials. Recently, nickel-titanium (NiTi) shape memory alloys have attracted much attention due to their shape memory effect and super-elasticity. However, this alloy consists of equal amounts of nickel and titanium, and nickel is a well known sensitizer to cause allergy or other deleterious effects in living tissues. Nickel ion leaching is correspondingly worse if the surface corrosion resistance deteriorates. We have therefore modified the NiTi surface by nitrogen plasma immersion ion implantation (PIII). The surface chemistry and corrosion resistance of the implanted samples were studied and compared with those of the untreated NiTi alloys, stainless steel, and Ti-6Al-4V alloy serving as controls. Immersion tests were carried out to investigate the extent of nickel leaching under simulated human body conditions and cytocompatibility tests were conducted using enhanced green fluorescent protein mice osteoblasts. The X-ray photoelectron spectroscopy results reveal that a thin titanium nitride (TiN) layer with higher hardness is formed on the surface after nitrogen PIII. The corrosion resistance of the implanted sample is also superior to that of the untreated NiTi and stainless steel and comparable to that of titanium alloy. The release of nickel ions is significantly reduced compared with the untreated NiTi. The sample with surface TiN exhibits the highest amount of cell proliferation whereas stainless steel fares the worst. Compared with coatings, the plasma-implanted structure does not delaminate as easily and nitrogen PIII is a viable way to improve the properties of NiTi orthopedic implants. PMID:17295246

  9. Triethyl orthoformate mediated a novel crosslinking method for the preparation of hydrogels for tissue engineering applications: characterization and in vitro cytocompatibility analysis

    International Nuclear Information System (INIS)

    This paper describes the development of a new crosslinking method for the synthesis of novel hydrogel films from chitosan and PVA for potential use in various biomedical applications. These hydrogel membranes were synthesized by blending different ratios of chitosan (CS) and poly(vinyl alcohol) (PVA) solutions and were crosslinked with 2.5% (w/v) triethyl orthoformate (TEOF) in the presence of 17% (w/v) sulfuric acid. The physical/chemical interactions and the presence of specific functional groups in the synthesized materials were evaluated by Fourier transform infrared (FT-IR) spectroscopy. The morphology, structure and pore size of the materials were investigated by scanning electron microscopy (SEM). Thermal gravimetric analysis (TGA) proved that these crosslinked hydrogel films have good thermal stability which was decreased as the CS ratio was increased. Differential scanning calorimetry (DSC) exhibited that CS and PVA were present in the amorphous form. The solution absorption properties were performed in phosphate buffer saline (PBS) solution of pH 7.4. The 20% PVA–80% CS crosslinked hydrogel films showed a greater degree of solution absorption (183%) as compared to other compositions. The hydrogels with greater CS concentration (60% and 80%) demonstrated relatively more porous structure, better cell viability and proliferation and also revealed good blood clotting ability even after crosslinking. Based on the observed facts these hydrogels can be tailored for their potential utilization in wound healing and skin tissue engineering applications. - Highlights: • A new method for covalently crosslinking of chitosan and PVA. • Triethyl orthoformate (TEOF) a new polymer–polymer crosslinking agent. • Hydrogels displayed a good solution absorption capacity. • Hydrogels demonstrated good cytocompatibility. • Good blood clotting potential was shown by these scaffolds

  10. Triethyl orthoformate mediated a novel crosslinking method for the preparation of hydrogels for tissue engineering applications: characterization and in vitro cytocompatibility analysis

    Energy Technology Data Exchange (ETDEWEB)

    Yar, Muhammad, E-mail: drmyar@ciitlahore.edu.pk [Interdisciplinary Research Center in Biomedical Materials, COMSATS Institute of Information Technology, Lahore 54000 (Pakistan); Shahzad, Sohail [Interdisciplinary Research Center in Biomedical Materials, COMSATS Institute of Information Technology, Lahore 54000 (Pakistan); Department of Chemistry, The Islamia University of Bahawalpur, Bahawalpur 63100 (Pakistan); Siddiqi, Saadat Anwar [Interdisciplinary Research Center in Biomedical Materials, COMSATS Institute of Information Technology, Lahore 54000 (Pakistan); Mahmood, Nasir [Department of Allied Health Sciences and Chemical Pathology, Department of Human Genetics and Molecular Biology, University of Health Sciences, Lahore (Pakistan); Rauf, Abdul [Department of Chemistry, The Islamia University of Bahawalpur, Bahawalpur 63100 (Pakistan); Anwar, Muhammad Sabieh [Department of Physics, Syed Babar Ali School of Science and Engineering, Lahore University of Management Sciences (LUMS), Opposite Sector U, D.H.A., Lahore 54792 (Pakistan); Chaudhry, Aqif Anwar [Interdisciplinary Research Center in Biomedical Materials, COMSATS Institute of Information Technology, Lahore 54000 (Pakistan); Rehman, Ihtesham ur [Interdisciplinary Research Center in Biomedical Materials, COMSATS Institute of Information Technology, Lahore 54000 (Pakistan); Department of Materials Science and Engineering, The Kroto Research Institute, The University of Sheffield, North Campus, Broad Lane, Sheffield S3 7HQ (United Kingdom)

    2015-11-01

    This paper describes the development of a new crosslinking method for the synthesis of novel hydrogel films from chitosan and PVA for potential use in various biomedical applications. These hydrogel membranes were synthesized by blending different ratios of chitosan (CS) and poly(vinyl alcohol) (PVA) solutions and were crosslinked with 2.5% (w/v) triethyl orthoformate (TEOF) in the presence of 17% (w/v) sulfuric acid. The physical/chemical interactions and the presence of specific functional groups in the synthesized materials were evaluated by Fourier transform infrared (FT-IR) spectroscopy. The morphology, structure and pore size of the materials were investigated by scanning electron microscopy (SEM). Thermal gravimetric analysis (TGA) proved that these crosslinked hydrogel films have good thermal stability which was decreased as the CS ratio was increased. Differential scanning calorimetry (DSC) exhibited that CS and PVA were present in the amorphous form. The solution absorption properties were performed in phosphate buffer saline (PBS) solution of pH 7.4. The 20% PVA–80% CS crosslinked hydrogel films showed a greater degree of solution absorption (183%) as compared to other compositions. The hydrogels with greater CS concentration (60% and 80%) demonstrated relatively more porous structure, better cell viability and proliferation and also revealed good blood clotting ability even after crosslinking. Based on the observed facts these hydrogels can be tailored for their potential utilization in wound healing and skin tissue engineering applications. - Highlights: • A new method for covalently crosslinking of chitosan and PVA. • Triethyl orthoformate (TEOF) a new polymer–polymer crosslinking agent. • Hydrogels displayed a good solution absorption capacity. • Hydrogels demonstrated good cytocompatibility. • Good blood clotting potential was shown by these scaffolds.

  11. A new composite scaffold of bioactive glass nanoparticles/graphene: Synchronous improvements of cytocompatibility and mechanical property.

    Science.gov (United States)

    Fan, Zengjie; Wang, Jinqing; Liu, Fengzhen; Nie, Yingying; Ren, Liling; Liu, Bin

    2016-09-01

    This study presents a simple method of synthesizing bioactive glass nanoparticles/graphene nanosheets composite (BGs/GNS) scaffolds using the sol-gel and mold-compressing strategies. Characterizations of BGs/GNS scaffold revealed that BGs with an average diameter of 28.75nm were densely anchored onto both sides of GNS. When the mass ratio of BGs to graphene oxide was set as 10, this scaffold showed better cytocompatibility and higher osseointegration ability with surrounding tissues than the other scaffolds. The introduction of GNS also significantly enhanced the hardness and Young's modulus of BGs. Given the excellent performance of this scaffold, it has potential applications in bone regeneration and implantation. PMID:27232307

  12. Cytocompatibility and antibacterial properties of sericin proteins%丝胶蛋白的细胞相容性和抗菌性能研究

    Institute of Scientific and Technical Information of China (English)

    陈忠敏; 罗琴; 张瑶琴; 刘琼

    2012-01-01

    研究了从茧壳、茧衣中提取丝胶蛋白(S1、S2)及茧壳丝胶进行酶解制各的小分子丝胶蛋白肽(S3)的细胞相容性,以及对革兰氏阴性菌、阳性菌的抗菌作用.结果表明:三种丝胶蛋白均“对细胞无毒性”,并随丝胶浓度的增大对细胞生长有促进作用.采用细菌生长抑制试验定量测试了各梯度浓度下丝胶的抑菌率,结果显示丝胶具有显著的抑菌作用,对金黄色葡萄球菌和的大肠杆菌抑制率由大到小依次为S3、S1、S2和S2、S3、S1,丝胶浓度对抑菌性有一定影响.研究结果表明丝胶是一种具有良好抑菌性能的生物相容性材料.%This paper studies the cytocompatibility of sericin proteins (S1, S2) extracted from cocoon shell and cocoon outer floss respectively and small molecule sericin protein peptide (S3) prepared by enzymolysis of cocoon shell sericin, and studies the antibacterial properties against Gram-negative bacteria and Gram-positive bacteria. Results show that: all these three kinds of sericin protein have not toxicity to cells, and show the function of promoting cell growth with the increase of sericin concentration. Have a quantitative test of bacterial inhibition rate of sericin under each concentration gradient by using bacterial growth inhibition test, and results show that sericin has significant antibacterial properties, and inhibition rates of Staphylococcus aureus and Escherichia coli in descending order are S3, S1, S2 and S2, S3, S1 respectively, and sericin concentration has effects on their antibacterial properties. The results suggest that sericin is a kind of biocompatible material with good antibacterial properties.

  13. Incorporation of fibronectin to enhance cytocompatibility in multilayer elastin-like protein scaffolds for tissue engineering

    OpenAIRE

    Ravi, Swathi; Caves, Jeffrey M.; Martinez, Adam W.; Haller, Carolyn A.; Chaikof, Elliot L.

    2012-01-01

    Recombinant, elastin-like protein (ELP) polymers are of significant interest for the engineering of compliant, resilient soft tissues due to a wide range of tunable mechanical properties, biostability, and biocompatibility. Here, we enhance endothelial cell (EC) and mesenchymal stem cell compatibility with ELP constructs by addition of fibronectin (Fn) to the surface or bulk of ELP hydrogels. We find that cell adhesion, proliferation, and migration can be modulated by Fn addition. Adsorption ...

  14. Gas Permeation, Mechanical Behavior and Cytocompatibility of Ultrathin Pure and Doped Diamond-Like Carbon and Silicon Oxide Films

    Directory of Open Access Journals (Sweden)

    Juergen M. Lackner

    2013-12-01

    Full Text Available Protective ultra-thin barrier films gather increasing economic interest for controlling permeation and diffusion from the biological surrounding in implanted sensor and electronic devices in future medicine. Thus, the aim of this work was a benchmarking of the mechanical oxygen permeation barrier, cytocompatibility, and microbiological properties of inorganic ~25 nm thin films, deposited by vacuum deposition techniques on 50 µm thin polyetheretherketone (PEEK foils. Plasma-activated chemical vapor deposition (direct deposition from an ion source was applied to deposit pure and nitrogen doped diamond-like carbon films, while physical vapor deposition (magnetron sputtering in pulsed DC mode was used for the formation of silicon as well as titanium doped diamond-like carbon films. Silicon oxide films were deposited by radio frequency magnetron sputtering. The results indicate a strong influence of nanoporosity on the oxygen transmission rate for all coating types, while the low content of microporosity (particulates, etc. is shown to be of lesser importance. Due to the low thickness of the foil substrates, being easily bent, the toughness as a measure of tendency to film fracture together with the elasticity index of the thin films influence the oxygen barrier. All investigated coatings are non-pyrogenic, cause no cytotoxic effects and do not influence bacterial growth.

  15. Bio-functionalized star PEG-coated PVDF surfaces for cytocompatibility-improved implant components.

    Science.gov (United States)

    Heuts, Jean; Salber, Jochen; Goldyn, Alexandra M; Janser, Romy; Möller, Martin; Klee, Doris

    2010-03-15

    Unmodified and GRGDS peptide-modified six arm PEG star based hydrogels (Star PEG) have been applied as a multifunctional, easy to handle coating system for textile polyvinylidene fluoride (PVDF) structures, which prevent unspecific protein and cell adsorption and control-specific cell adhesion. The reactive isocyanate-terminated Star PEG has been successfully applied to ammonia-plasma treated two- and three-dimensional PVDF surfaces. Easy modification of the surface hydrogel by mixing in of GRGDS peptide during the coating step or subsequent coupling of GRGDS was determined by TOF-SIMS. Unmodified and GRGDS-functionalized hydrogel surfaces show distinct protein repellency, as demonstrated by fluorescence microscopy after incubation with fluorescent labeled proteins and Surface MALDI-TOF-Mass Spectroscopy. Cell culture experiments with primary human dermal fibroblasts, primary fetal rat fibroblasts, and human osteoblasts on GRGDS and/or KRSR Star PEG-modified two- and three-dimensional substrates show advancement in cell adhesion and proliferation compared with untreated PVDF surfaces, whereas pure star PEG-coated surfaces show no cell adhesion. The combination of protein and cell repellent properties with specific biofunctionality and easy application of the coatings will enable their application for 3D-scaffolds. PMID:19431207

  16. Glycosaminoglycan-functionalized poly-lactide-co-glycolide nanoparticles: synthesis, characterization, cytocompatibility, and cellular uptake

    Directory of Open Access Journals (Sweden)

    Lamichhane SP

    2015-01-01

    Full Text Available Surya P Lamichhane,1 Neha Arya,1,2 Nirdesh Ojha,3 Esther Kohler,1 V Prasad Shastri1,2,41Institute for Macromolecular Chemistry, University of Freiburg, Freiburg, 2Helmholtz Virtual Institute on “Multifunctional Biomaterials for Medicine”, 3Laboratory for Process Technology, Department of Microsystems Engineering, University of Freiburg, Freiburg, 4Centre for Biological Signaling Studies (BIOSS, University of Freiburg, Freiburg, GermanyAbstract: The efficient delivery of chemotherapeutics to the tumor via nanoparticle (NP-based delivery systems remains a significant challenge. This is compounded by the fact that the tumor is highly dynamic and complex environment composed of a plurality of cell types and extracellular matrix. Since glycosaminoglycan (GAG production is altered in many diseases (or pathologies, NPs bearing GAG moieties on the surface may confer some unique advantages in interrogating the tumor microenvironment. In order to explore this premise, in the study reported here poly-lactide-co-glycolide (PLGA NPs in the range of 100–150 nm bearing various proteoglycans were synthesized by a single-step nanoprecipitation and characterized. The surface functionalization of the NPs with GAG moieties was verified using zeta potential measurements and X-ray photoelectron spectroscopy. To establish these GAG-bearing NPs as carriers of therapeutics, cellular toxicity assays were undertaken in lung epithelial adenocarcinoma (A549 cells, human pulmonary microvascular endothelial cells (HPMEC, and renal proximal tubular epithelial cells. In general NPs were well tolerated over a wide concentration range (100–600 µg/mL by all cell types and were taken up to appreciable extents without any adverse cell response in A549 cells and HPMEC. Further, GAG-functionalized PLGA NPs were taken up to different extents in A459 cells and HPMEC. In both cell systems, the uptake of heparin-modified NPs was diminished by 50%–65% in comparison to that of

  17. Cytocompatibility and mechanical properties of novel porous 316 L stainless steel.

    Science.gov (United States)

    Kato, Komei; Yamamoto, Akiko; Ochiai, Shojiro; Wada, Masahiro; Daigo, Yuzo; Kita, Koichi; Omori, Kenichi

    2013-07-01

    Novel 316 L stainless steel (SS) foam with 85% porosity and an open pore diameter of 70-440 μm was developed for hard tissue application. The foam sheet with a 200-μm diameter had superior cell proliferation and penetration as identified through in vitro experiments. Calcification of human osteosarcoma cells in the SS foam was observed. Multi-layered foam preparation is a potential alternative technique that satisfies multi-functional requirements such as cell penetration and binding strength to the solid metal. In tensile tests, Young's modulus and the strength of the SS foam were 4.0 GPa and 11.2 MPa respectively, which is comparable with human cancellous bone. PMID:23623090

  18. Synthesis, Characterization and Cytocompatibility of Polyurethaneurea Elastomers with Designed Elastase Sensitivity

    OpenAIRE

    Guan, Jianjun; Wagner, William R.

    2005-01-01

    In designing a synthetic scaffold for engineering soft, mechanically active tissues, desirable properties include elasticity, support of cell adhesion and growth, ease of processability, and responsiveness to in vivo remodeling. To achieve these properties, we have developed a family of thermoplastic elastomers, polyurethaneureas (PUs), that possess enzymatic remodeling capabilities in addition to simple hydrolytic lability. PUs were synthesized using either polycaprolactone or triblock copol...

  19. Characterization and cytocompatibility of carbon layers prepared by photo-induced chemical vapor deposition

    Czech Academy of Sciences Publication Activity Database

    Kubová, O.; Švorčík, V.; Heitz, J.; Moritz, S.; Romanin, C.; Matějka, P.; Macková, Anna

    2007-01-01

    Roč. 515, č. 17 (2007), s. 6765-6772. ISSN 0040-6090 R&D Projects: GA MŠk(CZ) LC06041 Institutional research plan: CEZ:AV0Z10480505 Keywords : Polytetrafluoroethylene * Carbon layer * CVD deposition * Layer properties * Cell proliferation Subject RIV: JJ - Other Materials Impact factor: 1.693, year: 2007

  20. Nano-structured and functionalized surfaces for cytocompatibility improvement and bactericidal action

    Czech Academy of Sciences Publication Activity Database

    Slepička, P.; Kasálková-Slepičková, N.; Siegel, J.; Kolská, Z.; Bačáková, Lucie; Švorčík, V.

    2015-01-01

    Roč. 33, 6 Part 2 (2015), s. 1120-1129. ISSN 0734-9750 R&D Projects: GA ČR(CZ) GBP108/12/G108 Institutional support: RVO:67985823 Keywords : polymers * surface modification * cell-material interaction * tissue engineering Subject RIV: JJ - Other Materials Impact factor: 9.015, year: 2014

  1. Antibacterial Activity and Cytocompatibility of PLGA/CuO Hybrid Nanofiber Scaffolds Prepared by Electrospinning

    OpenAIRE

    Adnan Haider; Sanghwa Kwak; Kailash Chandra Gupta; Inn-Kyu Kang

    2015-01-01

    The PLGA/CuO hybrid nanofibers scaffolds were prepared via electrospinning technique. The presence of CuO in the PLGA scaffolds was confirmed by transmission electron microscope (TEM) and X-ray photoelectron spectroscopy (XPS). The scaffolds were subjected to various antibacterial and cytobiocompatibility tests. The results not only showed excellent adhesion, proliferation, and viability (live/dead staining) for fibroblastic cells but also revealed that PLGA/CuO hybrid nanofiber scaffolds inh...

  2. Fabrication, nanomechanical characterization, and cytocompatibility of gold-reinforced chitosan bio-nanocomposites

    Energy Technology Data Exchange (ETDEWEB)

    Patel, Nimitt G. [Department of Mechanical and Aeronautical Engineering, Clarkson University, Potsdam, NY, 13699 (United States); Materials Science and Engineering PhD Program, Clarkson University, Potsdam, NY, 13699 (United States); Kumar, Ajeet [Center for Advanced Materials Processing, Clarkson University, Potsdam, NY, 13699 (United States); Jayawardana, Veroni N. [Department of Mathematics, Clarkson University, Potsdam, NY, 13699 (United States); Woodworth, Craig D. [Department of Biology, Clarkson University, Potsdam, NY, 13699 (United States); Yuya, Philip A., E-mail: pyuya@clarkson.edu [Department of Mechanical and Aeronautical Engineering, Clarkson University, Potsdam, NY, 13699 (United States)

    2014-11-01

    Chitosan, a naturally derived polymer represents one of the most technologically important classes of active materials with applications in a variety of industrial and biomedical fields. Gold nanoparticles (∼ 32 nm) were synthesized via a citrate reduction method from chloroauric acid and incorporated in Chitosan matrix. Bio-nanocomposite films with varying concentrations of gold nanoparticles were prepared through solution casting process. Uniform distribution of gold nanoparticles was achieved throughout the chitosan matrix and was confirmed with SEM. Synthesis outcomes and prepared nanocomposites were characterized using SEM, TEM, EDX, SAED, UV–vis, XRD, DLS, and Zeta potential for their physical, morphological and structural properties. Nanoscale properties of materials under the influence of temperature were characterized through nanoindentation techniques. From quasi-static nanoindentation, it was observed that hardness and reduced modulus of the nanocomposites were increased significantly in direct proportion to the gold nanoparticle concentration. Gold nanoparticle concentration also showed positive impact on storage modulus and thermal stability of the material. The obtained films were confirmed to be biocompatible by their ability to support growth of human cells in vitro. In summary, the results show enhanced mechanical properties with increasing gold nanoparticle concentration, and provide better understanding of the structure–property relationships of such biocompatible materials for potential biomedical applications. - Highlights: • We fabricated gold reinforced chitosan nanocomposite for biomedical applications. • Gold nanoparticles significantly enhanced nanomechanical properties of chitosan. • Nanocomposite films supported growth of human cells in vitro. • Gold nanoparticles significantly improved cell proliferation on chitosan films.

  3. Fabrication, nanomechanical characterization, and cytocompatibility of gold-reinforced chitosan bio-nanocomposites

    International Nuclear Information System (INIS)

    Chitosan, a naturally derived polymer represents one of the most technologically important classes of active materials with applications in a variety of industrial and biomedical fields. Gold nanoparticles (∼ 32 nm) were synthesized via a citrate reduction method from chloroauric acid and incorporated in Chitosan matrix. Bio-nanocomposite films with varying concentrations of gold nanoparticles were prepared through solution casting process. Uniform distribution of gold nanoparticles was achieved throughout the chitosan matrix and was confirmed with SEM. Synthesis outcomes and prepared nanocomposites were characterized using SEM, TEM, EDX, SAED, UV–vis, XRD, DLS, and Zeta potential for their physical, morphological and structural properties. Nanoscale properties of materials under the influence of temperature were characterized through nanoindentation techniques. From quasi-static nanoindentation, it was observed that hardness and reduced modulus of the nanocomposites were increased significantly in direct proportion to the gold nanoparticle concentration. Gold nanoparticle concentration also showed positive impact on storage modulus and thermal stability of the material. The obtained films were confirmed to be biocompatible by their ability to support growth of human cells in vitro. In summary, the results show enhanced mechanical properties with increasing gold nanoparticle concentration, and provide better understanding of the structure–property relationships of such biocompatible materials for potential biomedical applications. - Highlights: • We fabricated gold reinforced chitosan nanocomposite for biomedical applications. • Gold nanoparticles significantly enhanced nanomechanical properties of chitosan. • Nanocomposite films supported growth of human cells in vitro. • Gold nanoparticles significantly improved cell proliferation on chitosan films

  4. Cytocompatibility evaluation and surface characterization of TiNi deformed by high-pressure torsion

    International Nuclear Information System (INIS)

    Effect of high-pressure torsion (HPT) deformation on biocompatibility and surface chemistry of TiNi was systematically investigated. Ti–50 mol% Ni was subjected to HPT straining for different numbers of turns, N = 0.25, 0.5, 1, 5 and 10 at a rotation speed of 1 rpm. X-ray photoelectron spectroscopy observations after 7 days of cell culture revealed the changes in the surface oxide composition, enrichment of Ti and detection of nitrogen derived from organic molecules in the culture medium. Plating efficiency of L929 cells was slightly increased by HPT deformation though no significant difference was observed. Albumin adsorption was higher in HPT-deformed samples, while vitronectin adsorption was peaked at N = 1. HPT deformation was also found to effectively suppress the Ni ion release from the TiNi samples into the cell culture medium even after the low degree of deformation at N = 0.25. - Highlights: • Nanostructured Ti–50 mol%Ni alloy was produced using high-pressure torsion. • HPT deformation improved L929 growth on TiNi samples. • Changes in surface chemistry were observed in HPT deformed samples. • Protein adsorption behavior was influenced by the surface chemistry. • Ni ion release was suppressed in HPT deformed samples

  5. Drug delivery property, bactericidal property and cytocompatibility of magnetic mesoporous bioactive glass

    International Nuclear Information System (INIS)

    A multifunctional magnetic mesoporous bioactive glass (MMBG) has been widely used for a drug delivery system, but its biological properties have been rarely reported. Herein, the effects of mesopores and Fe3O4 nanoparticles on drug loading–release property, bactericidal property and biocompatibility have been investigated by using mesoporous bioactive glass (MBG) and non-mesoporous bioactive glass (NBG) as control samples. Both MMBG and MBG have better drug loading efficiency than NBG because they possess ordered mesoporous channels, big specific surface areas and high pore volumes. As compared with MBG, the Fe3O4 nanoparticles in MMBG not only provide magnetic property, but also improve sustained drug release property. For gentamicin-loaded MMBG (Gent-MMBG), the sustained release of gentamicin and the Fe3O4 nanoparticles minimize bacterial adhesion significantly and prevent biofilm formation against Staphylococcus aureus (S. aureus) and Staphylococcus epidermidis (S. epidermidis). Moreover, the magnetic Fe3O4 nanoparticles in MMBG can promote crucial cell functions such as cell adhesion, spreading and proliferation. The excellent biocompatibility and drug delivery property of MMBG suggest that Gent-MMBG has great potentials for treatment of implant-associated infections. - Highlights: • Multifunctional magnetic mesoporous bioactive glass is fabricated. • The bioactive glass has great biocompatibility. • The bioactive glass exhibits high drug loading–release properties. • The drug delivery system has bactericidal property. • Magnetic particles improve cell adhesion, spreading and proliferation

  6. Drug delivery property, bactericidal property and cytocompatibility of magnetic mesoporous bioactive glass

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Yi-Zhuo [The Education Ministry Key Lab of Resource Chemistry, Shanghai Normal University, Shanghai 200234 (China); Shanghai Key Laboratory of Rare Earth Functional Materials, Shanghai Normal University, Shanghai 200234 (China); Li, Yang [Shanghai Key Laboratory of Orthopedic Implant, Department of Orthopedic Surgery, Shanghai Ninth People' s Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200011 (China); Yu, Xi-Bin [The Education Ministry Key Lab of Resource Chemistry, Shanghai Normal University, Shanghai 200234 (China); Shanghai Key Laboratory of Rare Earth Functional Materials, Shanghai Normal University, Shanghai 200234 (China); Liu, Li-Na [Shanghai Key Laboratory of Orthopedic Implant, Department of Orthopedic Surgery, Shanghai Ninth People' s Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200011 (China); Zhu, Zhen-An, E-mail: zhuzhenan2006@126.com [Shanghai Key Laboratory of Orthopedic Implant, Department of Orthopedic Surgery, Shanghai Ninth People' s Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200011 (China); Guo, Ya-Ping, E-mail: ypguo@shnu.edu.cn [The Education Ministry Key Lab of Resource Chemistry, Shanghai Normal University, Shanghai 200234 (China); Shanghai Key Laboratory of Rare Earth Functional Materials, Shanghai Normal University, Shanghai 200234 (China)

    2014-08-01

    A multifunctional magnetic mesoporous bioactive glass (MMBG) has been widely used for a drug delivery system, but its biological properties have been rarely reported. Herein, the effects of mesopores and Fe{sub 3}O{sub 4} nanoparticles on drug loading–release property, bactericidal property and biocompatibility have been investigated by using mesoporous bioactive glass (MBG) and non-mesoporous bioactive glass (NBG) as control samples. Both MMBG and MBG have better drug loading efficiency than NBG because they possess ordered mesoporous channels, big specific surface areas and high pore volumes. As compared with MBG, the Fe{sub 3}O{sub 4} nanoparticles in MMBG not only provide magnetic property, but also improve sustained drug release property. For gentamicin-loaded MMBG (Gent-MMBG), the sustained release of gentamicin and the Fe{sub 3}O{sub 4} nanoparticles minimize bacterial adhesion significantly and prevent biofilm formation against Staphylococcus aureus (S. aureus) and Staphylococcus epidermidis (S. epidermidis). Moreover, the magnetic Fe{sub 3}O{sub 4} nanoparticles in MMBG can promote crucial cell functions such as cell adhesion, spreading and proliferation. The excellent biocompatibility and drug delivery property of MMBG suggest that Gent-MMBG has great potentials for treatment of implant-associated infections. - Highlights: • Multifunctional magnetic mesoporous bioactive glass is fabricated. • The bioactive glass has great biocompatibility. • The bioactive glass exhibits high drug loading–release properties. • The drug delivery system has bactericidal property. • Magnetic particles improve cell adhesion, spreading and proliferation.

  7. Microstructures, mechanical and cytocompatibility of degradable Mg–Zn based orthopedic biomaterials

    International Nuclear Information System (INIS)

    Highlights: • Sr is an effective grain refiner to backward extruded Mg–Zn–Sr alloy. • The improved strength is associated with fine grain and homogenous precipitates. • The corrosion properties are decreased with increased Sr concentration. • The stable degradation rate is achieved after backward extrusion. • High biocompatibility is observed by extract assay method using L929 cell line. - Abstract: The Mg–1Zn–xSr (x = 0.2, 0.5, 0.8 and 1 wt.%) alloys have been prepared by zone purifying solidification followed by backward extrusion (BE). The grain size was reduced and the hardness was improved with the increased concentration of strontium (Sr) after backward extrusion. The BE–Mg–1Zn–0.8Sr alloy was mostly composed of fine precipitates (MgZn and Mg17Sr2) and Mg matrix. At the same time, the mechanical properties of BE–Mg–Zn–Sr alloys were increased with the increment of strontium, which were strongly associated with fine average grain size and homogeneous secondary precipitates. The degradation rate is significantly increased when Sr content is over 0.8 wt.%. The homogenous degradation rate is achieved. The degradation products show good biocompatibility evaluated by MTT method using L929 cell line. It is demonstrated that the micro-alloying element of Sr is a potential approach to develop novel Mg–Zn based biomaterials

  8. Degradability, cytocompatibility, and osteogenesis of porous scaffolds of nanobredigite and PCL–PEG–PCL composite

    Science.gov (United States)

    Hou, Jun; Fan, Donghui; Zhao, Lingming; Yu, Baoqin; Su, Jiacan; Wei, Jie; Shin, Jung-Woog

    2016-01-01

    Biocomposite scaffolds were fabricated by incorporation of nanobredigite (n-BD) into the polymer of poly(ε-caprolactone)–poly(ethyleneglycol)–poly(ε-caprolactone) (PCL–PEG–PCL). The results revealed that the addition of n-BD into PCL–PEG–PCL significantly improved water absorption, compressive strength, and degradability of the scaffolds of n-BD/PCL–PEG–PCL composite (n-BPC) compared with PCL–PEG–PCL scaffolds alone. In addition, the proliferation and alkaline phosphatase activity of MG63 cells cultured on n-BPC scaffolds were obviously higher than that cultured on PCL–PEG–PCL scaffolds. Moreover, the results of the histological evaluation from the animal model revealed that the n-BPC scaffolds significantly improved new bone formation compared with the PCL–PEG–PCL scaffolds, indicating good osteogenesis. The n-BPC scaffolds with good biocompatibility could stimulate cell proliferation, differentiation, and bone tissue regeneration and would be an excellent candidate for bone defect repair. PMID:27555774

  9. Engineered Hybrid Scaffolds of Poly(vinyl alcohol)/Bioactive Glass for Potential Bone Engineering Applications: Synthesis, Characterization, Cytocompatibility, and Degradation

    OpenAIRE

    Costa, Hermes S; Mansur, Alexandra A.P.; Marivalda M. Pereira; Mansur, Herman S

    2012-01-01

    The synthesis, characterization, preliminary cytocompatibility, and degradation behavior of the hybrids based on 70% Poly(vinyl alcohol) and 30% bioactive glass (58SiO2–33CaO–9P2O5, BaG) with macroporous tridimensional structure is reported for the first time. The effect of glutaraldehyde covalent crosslinker in the organic-inorganic nanostructures produced and, as a consequence, tailoring the hybrids properties was investigated. The PVA/BaG hybrids scaffolds are characterized by Fourier tran...

  10. Characterization and cytocompatibility of an antibiotic/chitosan/cyclodextrins nanocoating on titanium implants.

    Science.gov (United States)

    Mattioli-Belmonte, Monica; Cometa, Stefania; Ferretti, Concetta; Iatta, Roberta; Trapani, Adriana; Ceci, Edmondo; Falconi, Mirella; De Giglio, Elvira

    2014-09-22

    A novel ciprofloxacin loaded chitosan nanoparticle-based coating onto titanium substrates has been developed and characterized to obtain an orthopaedic implant surface able to in situ release the antibiotic for the prevention of post-operative infections. Ciprofloxacin loaded chitosan nanoparticles were obtained using the combination of sulfobutyl ether-beta-cyclodextrin and gamma-cyclodextrin. The resulting nanoparticulate system was characterized by TEM, HPLC and XPS. Particle size was in the range 426-552 nm and zeta potential values were around +30 mV. This antibacterial coating was able to in vitro inhibit two nosocomial Staphylococcus aureus strains growth, with a reduction of about 20 times compared to controls. No impairment in MG63 osteoblast-like cells viability, adhesion and gene expression were detected at 48 h, 7 and 14 days of culture. Overall, the investigated coating represents a promising candidate for the development of a new antibiotic carrier for titanium implants. PMID:24906744

  11. Antibacterial Activity and Cytocompatibility of PLGA/CuO Hybrid Nanofiber Scaffolds Prepared by Electrospinning

    Directory of Open Access Journals (Sweden)

    Adnan Haider

    2015-01-01

    Full Text Available The PLGA/CuO hybrid nanofibers scaffolds were prepared via electrospinning technique. The presence of CuO in the PLGA scaffolds was confirmed by transmission electron microscope (TEM and X-ray photoelectron spectroscopy (XPS. The scaffolds were subjected to various antibacterial and cytobiocompatibility tests. The results not only showed excellent adhesion, proliferation, and viability (live/dead staining for fibroblastic cells but also revealed that PLGA/CuO hybrid nanofiber scaffolds inhibited both Gram-positive and Gram-negative bacterial growth. The mechanism of the antibacterial activity was concluded to be based on the CuO nanoparticles and Cu++ ions release. It is, therefore, evaluated that PLGA/CuO hybrid nanofiber scaffolds can be a useful candidate for wound dressing.

  12. Degradability, cytocompatibility, and osteogenesis of porous scaffolds of nanobredigite and PCL–PEG–PCL composite

    Directory of Open Access Journals (Sweden)

    Hou J

    2016-07-01

    Full Text Available Jun Hou,1 Donghui Fan,2 Lingming Zhao,2 Baoqin Yu,3 Jiacan Su,3 Jie Wei,2 Jung-Woog Shin4 1The First Affiliated Hospital of Anhui Medical University, Department of Oral and Maxillofacial Surgery, Hefei, 2Key Laboratory for Ultrafine Materials of Ministry of Education and The State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, 3Department of Orthopaedics Trauma, Changhai Hospital, Second Military Medical University, Shanghai, People’s Republic of China; 4Department of Biomedical Engineering, Inje University, Gimhae, Republic of Korea Abstract: Biocomposite scaffolds were fabricated by incorporation of nanobredigite (n-BD into the polymer of poly(ε-caprolactone–poly(ethyleneglycol–poly(ε-caprolactone (PCL–PEG–PCL. The results revealed that the addition of n-BD into PCL–PEG–PCL significantly improved water absorption, compressive strength, and degradability of the scaffolds of n-BD/PCL–PEG–PCL composite (n-BPC compared with PCL–PEG–PCL scaffolds alone. In addition, the proliferation and alkaline phosphatase activity of MG63 cells cultured on n-BPC scaffolds were obviously higher than that cultured on PCL–PEG–PCL scaffolds. Moreover, the results of the histological evaluation from the animal model revealed that the n-BPC scaffolds significantly improved new bone formation compared with the PCL–PEG–PCL scaffolds, indicating good osteogenesis. The n-BPC scaffolds with good biocompatibility could stimulate cell proliferation, differentiation, and bone tissue regeneration and would be an excellent candidate for bone defect repair. Keywords: nanobredigite, PCL–PEG–PCL, biocomposite scaffolds, degradability, osteo­genesis

  13. Incorporation of strontium up to 5 Mol. (% to hydroxyapatite did not affect its cytocompatibility

    Directory of Open Access Journals (Sweden)

    Débora dos Santos Tavares

    2011-12-01

    Full Text Available The aim of this work was to produce hydroxyapatite (HA granules containing 0, 0.5, 1 and 5 mol. (% of strontium (Sr, evaluate the physico-chemical properties and also the cytotoxicity by three different parameters of cell viability (ISO 10993-5, 10993-12. The physico-chemical characterization was carried out by using X-ray diffraction (XRD, Fourier-transform infrared spectroscopy (FTIR and X-ray fluorescence (XRF. The XRD profile presented the main peaks of HA (JCPDS 860740 and the absorption bands of HA were identified by FTIR. The XRF results showed that the strontium concentration was close to the theoretical value. Regarding the cytotoxicity assays, the incorporation of strontium up to 5 mol. (% to the HA did not affected dehydrogenase activity (XTT, 2,3-bis[2-methyloxy-4-nitro-5-sulfophenyl]-2H-tetrazolium-5-carboxanilide, membrane integrity (neutral red uptake or DNA contend (incorporation of crystal violet, in relation to HA alone. In conclusion, hydroxyapatite containing from 0.5 to 5 mol. (% of Sr was successfully produced and presented no cytotoxicity.

  14. Microstructure-modified biodegradable magnesium alloy for promoting cytocompatibility and wound healing in vitro.

    Science.gov (United States)

    Lin, Da-Jun; Hung, Fei-Yi; Yeh, Ming-Long; Lui, Truan-Sheng

    2015-10-01

    The microstructure of biomedical magnesium alloys has great influence on anti-corrosion performance and biocompatibility. In practical application and for the purpose of microstructure modification, heat treatments were chosen to provide widely varying microstructures. The aim of the present work was to investigate the influence of the microstructural parameters of an Al-free Mg-Zn-Zr alloy (ZK60), and the corresponding heat-treatment-modified microstructures on the resultant corrosion resistance and biological performance. Significant enhancement in corrosion resistance was obtained in Al-free Mg-Zn-Zr alloy (ZK60) through 400 °C solid-solution heat treatment. It was found that the optimal condition of solid-solution treatment homogenized the matrix and eliminated internal defects; after which, the problem of unfavorable corrosion behavior was improved. Further, it was also found that the Mg ion-release concentration from the modified ZK60 significantly induced the cellular activity of fibroblast cells, revealing in high viability value and migration ability. The experimental evidence suggests that this system can further accelerate wound healing. From the perspective of specific biomedical applications, this research result suggests that the heat treatment should be applied in order to improve the biological performance. PMID:26411444

  15. Minocycline-released hydroxyapatite-gelatin nanocomposite and its cytocompatibility in vitro

    International Nuclear Information System (INIS)

    The incorporation of antibacterial agents into biomaterials is extremely desirable for repairing bone defects. Minocycline, a semi-synthetic tetracycline antibiotic, is active against aerobic, anaerobic, Gram-positive and Gram-negative bacteria, and can enhance bone formation, decrease connective tissue breakdown and diminish bone resorption. In this study, a novel minocycline-releasing biomaterial was synthesized using a biomimetic method. A measured amount of an acidic hydroxyapatite and minocycline solution was respectively added to a gelatin solution and kept at 40 deg. C and pH 7-8 for 2 h. The mixture was aged overnight, lyophilized and a hydroxyapatite-gelatin-minocycline composite was obtained. The composite was co-cultured with rat bone marrow stromal cells (BMSCs) in vitro. Our results show that nanohydroxyapatite was distributed evenly in the fibrils of the gelatin. Minocycline was incorporated into the composite and could be released from the composite particles slowly over 2 weeks in vitro. The composite promoted BMSC adhesion, proliferation and differentiation in vitro. The approach described here may provide a basis for the preparation of an antibacterial biomaterial for bone regeneration.

  16. Minocycline-released hydroxyapatite-gelatin nanocomposite and its cytocompatibility in vitro

    Energy Technology Data Exchange (ETDEWEB)

    Dou Xiaochen; Zhu Xiaopeng; Zhou Jian; Cai Huaqiong; Li Quanli [Key Laboratory of Oral Disease Research of Anhui Province, Stomatologic Hospital and Collage, Anhui Medical University, Hefei (China); Tang Jian, E-mail: ql-li@126.com [Department of Orthopedic Surgery, The First Hospital of Anhui Medical University, Hefei (China)

    2011-04-15

    The incorporation of antibacterial agents into biomaterials is extremely desirable for repairing bone defects. Minocycline, a semi-synthetic tetracycline antibiotic, is active against aerobic, anaerobic, Gram-positive and Gram-negative bacteria, and can enhance bone formation, decrease connective tissue breakdown and diminish bone resorption. In this study, a novel minocycline-releasing biomaterial was synthesized using a biomimetic method. A measured amount of an acidic hydroxyapatite and minocycline solution was respectively added to a gelatin solution and kept at 40 deg. C and pH 7-8 for 2 h. The mixture was aged overnight, lyophilized and a hydroxyapatite-gelatin-minocycline composite was obtained. The composite was co-cultured with rat bone marrow stromal cells (BMSCs) in vitro. Our results show that nanohydroxyapatite was distributed evenly in the fibrils of the gelatin. Minocycline was incorporated into the composite and could be released from the composite particles slowly over 2 weeks in vitro. The composite promoted BMSC adhesion, proliferation and differentiation in vitro. The approach described here may provide a basis for the preparation of an antibacterial biomaterial for bone regeneration.

  17. Foldable and Cytocompatible Sol-gel TiO2 Photonics

    Science.gov (United States)

    Li, Lan; Zhang, Ping; Wang, Wei-Ming; Lin, Hongtao; Zerdoum, Aidan B.; Geiger, Sarah J.; Liu, Yangchen; Xiao, Nicholas; Zou, Yi; Ogbuu, Okechukwu; Du, Qingyang; Jia, Xinqiao; Li, Jingjing; Hu, Juejun

    2015-09-01

    Integrated photonics provides a miniaturized and potentially implantable platform to manipulate and enhance the interactions between light and biological molecules or tissues in in-vitro and in-vivo settings, and is thus being increasingly adopted in a wide cross-section of biomedical applications ranging from disease diagnosis to optogenetic neuromodulation. However, the mechanical rigidity of substrates traditionally used for photonic integration is fundamentally incompatible with soft biological tissues. Cytotoxicity of materials and chemicals used in photonic device processing imposes another constraint towards these biophotonic applications. Here we present thin film TiO2 as a viable material for biocompatible and flexible integrated photonics. Amorphous TiO2 films were deposited using a low temperature (integration on plastic substrates. High-index-contrast flexible optical waveguides and resonators were fabricated using the sol-gel TiO2 material, and resonator quality factors up to 20,000 were measured. Following a multi-neutral-axis mechanical design, these devices exhibit remarkable mechanical flexibility, and can sustain repeated folding without compromising their optical performance. Finally, we validated the low cytotoxicity of the sol-gel TiO2 devices through in-vitro cell culture tests. These results demonstrate the potential of sol-gel TiO2 as a promising material platform for novel biophotonic devices.

  18. Development of Composite Poly(Lactide-co-Glycolide)- Nanodiamond Scaffolds for Bone Cell Growth

    Czech Academy of Sciences Publication Activity Database

    Brady, M.A.; Renzing, A.; Douglas, T.E.L.; Liu, Q.; Wille, S.; Pařízek, Martin; Bačáková, Lucie; Kromka, Alexander; Jarošová, Markéta; Godier, G.; Warnke, P. H.

    2015-01-01

    Roč. 15, č. 2 (2015), s. 1060-1069. ISSN 1533-4880 R&D Projects: GA ČR(CZ) GBP108/12/G108 Institutional support: RVO:67985823 ; RVO:68378271 Keywords : diamond nanoparticles * PLGA * human MSC * nanofibres * cytocompatibility * cell growth Subject RIV: JJ - Other Materials Impact factor: 1.556, year: 2014

  19. Influence of non-thermal TiCl4/Ar+O2 plasma-assisted TiOx based coatings on the surface of polypropylene (PP) films for the tailoring of surface properties and cytocompatibility.

    Science.gov (United States)

    Pandiyaraj, K N; Kumar, A Arun; Ramkumar, M C; Sachdev, A; Gopinath, P; Cools, Pieter; De Geyter, N; Morent, R; Deshmukh, R R; Hegde, P; Han, C; Nadagouda, M N

    2016-05-01

    The superior bulk properties (corrosion resistance, high strength to weight ratio, relatively low cost and easy processing) of hydrocarbon based polymers such as polypropylene (PP) have contributed significantly to the development of new biomedical applications such as artificial organs and cell scaffolds. However, low cell affinity is one of the main draw backs for PP due to its poor surface properties. In tissue engineering, physico-chemical surface properties such as hydrophilicity, polar functional groups, surface charge and morphology play a crucial role to enrich the cell proliferation and adhesion. In this present investigation TiOx based biocompatible coatings were developed on the surface of PP films via DC excited glow discharge plasma, using TiCl4/Ar+O2 gas mixture as a precursor. Various TiOx-based coatings are deposited on the surface of PP films as a function of discharge power. The changes in hydrophilicity of the TiOx/PP film surfaces were studied using contact angle analysis and surface energy calculations by Fowke's approximation. X-ray photo-electron spectroscopy (XPS) was used to investigate the surface chemical composition of TiOx/PP films. The surface morphology of the obtained TiOx/PP films was investigated by scanning electron and transmission electron microscopy (SEM &TEM). Moreover, the surface topography of the material was analyzed by atomic force microscopy (AFM). The cytocompatibility of the TiOx/PP films was investigated via in vitro analysis (cell viability, adhesion and cytotoxicity) using NIH3T3 (mouse embryonic fibroblast) cells. Furthermore the antibacterial activities of TiOx/PP films were also evaluated against two distinct bacterial models namely Gram positive Staphylococcus aureus (S.aureus) and Gram negative Escherichia coli DH5α. (E.coli) bacteria. XPS results clearly indicate the successful incorporation of TiOx and oxygen containing polar functional groups on the surface of plasma treated PP films. Moreover the surface

  20. Highly versatile nanohydrogel platform based on riboflavin-polysaccharide derivatives useful in the development of intrinsically fluorescent and cytocompatible drug carriers.

    Science.gov (United States)

    Di Meo, Chiara; Montanari, Elita; Manzi, Lucio; Villani, Claudio; Coviello, Tommasina; Matricardi, Pietro

    2015-01-22

    In this work we describe a new nanohydrogel platform, based on polysaccharides modified with the hydrophobic and fluorescent molecule riboflavin tetrabutyrate, which leads to innovative structures useful for drug delivery applications. Hyaluronic acid and pullulan were chosen as representative of anionic and neutral polysaccharides, respectively, and the bromohexyl derivative of riboflavin tetrabutyrate was chemically linked to these polymer chains. Because of such derivatization, polymer chains were able to self-assemble in aqueous environment thus forming nanohydrogels, with mean diameters of about 312 and 210 nm, for hyaluronan and pullulan, respectively. These new nanohydrogels showed low polydispersity index, and negative ζ-potential. Moreover, the nanohydrogels, which can be easily loaded with model drugs, showed long-term stability in water and physiological conditions and excellent cytocompatibility. All these properties allow to consider these intrinsically fluorescent nanohydrogels suitable for the formulation of innovative drug dosage forms. PMID:25439925

  1. Significance of Nano- and Microtopography for Cell-Surface Interactions in Orthopaedic Implants

    Directory of Open Access Journals (Sweden)

    M. Jäger

    2007-09-01

    Full Text Available Cell-surface interactions play a crucial role for biomaterial application in orthopaedics. It is evident that not only the chemical composition of solid substances influence cellular adherence, migration, proliferation and differentiation but also the surface topography of a biomaterial. The progressive application of nanostructured surfaces in medicine has gained increasing interest to improve the cytocompatibility and osteointegration of orthopaedic implants. Therefore, the understanding of cell-surface interactions is of major interest for these substances. In this review, we elucidate the principle mechanisms of nano- and microscale cell-surface interactions in vitro for different cell types onto typical orthopaedic biomaterials such as titanium (Ti, cobalt-chrome-molybdenum (CoCrMo alloys, stainless steel (SS, as well as synthetic polymers (UHMWPE, XLPE, PEEK, PLLA. In addition, effects of nano- and microscaled particles and their significance in orthopaedics were reviewed. The significance for the cytocompatibility of nanobiomaterials is discussed critically.

  2. Microstructure, corrosion resistance and cytocompatibility of Mg-5Y-4Rare Earth-0.5Zr (WE54) alloy

    Energy Technology Data Exchange (ETDEWEB)

    Smola, Bohumil, E-mail: bohumil.smola@mff.cuni.cz [Charles University Prague, Faculty of Mathematics and Physics, Ke Karlovu 5, 121 16 Praha 2 (Czech Republic); Joska, Ludek [Institute of Chemical Technology Prague, Faculty of Chemical Technology, Technicka 5, 166 28 Praha 6 (Czech Republic); Brezina, Vitezslav [University of South Bohemia, Institute of Physical Biology, Zamek 136, 373 33 Nove Hrady (Czech Republic); Stulikova, Ivana [Charles University Prague, Faculty of Mathematics and Physics, Ke Karlovu 5, 121 16 Praha 2 (Czech Republic); Hnilica, Frantisek [Czech Technical University in Prague, Faculty of Mechanical Engineering, Karlovo namesti 13, 121 35 Praha 2 (Czech Republic)

    2012-05-01

    Conventionally cast Mg-5Y-4Rare Earth-0.5Zr alloy (WE54) was solution treated (525 Degree-Sign C/8 h - T4) and one part subsequently aged (200 Degree-Sign C/16 h - T6). Powder from the cast WE54 alloy prepared by gas atomizing was consolidated by extrusion at 250 Degree-Sign C or 400 Degree-Sign C. Dense triangular arrangement of prismatic plates of transient D0{sub 19} and C-base centered orthorhombic phases precipitated in the {alpha}-Mg matrix during the T6 treatment. Both alloys prepared by powder metallurgy exhibit similar microstructure consisting of {approx} 4-6 {mu}m {alpha}-Mg matrix fibers surrounded by particles of the equilibrium Mg{sub 5}(Y, Nd) phase and of oxides. Open circuit potential and polarization resistance in the isotonic saline (9 g/l NaCl/H{sub 2}O) were monitored for 24 h. The corrosion rate of the T4 and T6 treated alloys was about 80 times lower than that of commercial Mg. Both alloys prepared by powder metallurgy exhibited approximately 8 times higher corrosion resistance than commercial Mg. The human MG-63 osteoblast-like cells spreading and division in the extracts (0.28 g in 28 ml of EMEM) of all 4 alloys were monitored by cinemicrography for 24 h. The MG-63 cells proliferate without cytotoxicity in all extracts. - Highlights: Black-Right-Pointing-Pointer T6 treated WE54 alloy exhibit dense triangular arrangement of {beta} Double-Prime and {beta} Prime phase prismatic plates. Black-Right-Pointing-Pointer Microstructure of PM prepared WE54 alloy consists of {alpha}-Mg phase cells surrounded by {beta} phase particles. Black-Right-Pointing-Pointer PM produced WE54 corroded 10 times faster in physiological solution thanT4 and T6 treated WE54. Black-Right-Pointing-Pointer MG63 cell spreading in EMEM extracts of PM prepared WE54 is comparable to that in control EMEM. Black-Right-Pointing-Pointer Cell mitosis is enhanced in PM WE54 extracts compared to the control and extracts of T4 and T6 WE54.

  3. Microstructure, corrosion resistance and cytocompatibility of Mg–5Y–4Rare Earth–0.5Zr (WE54) alloy

    International Nuclear Information System (INIS)

    Conventionally cast Mg–5Y–4Rare Earth–0.5Zr alloy (WE54) was solution treated (525 °C/8 h — T4) and one part subsequently aged (200 °C/16 h — T6). Powder from the cast WE54 alloy prepared by gas atomizing was consolidated by extrusion at 250 °C or 400 °C. Dense triangular arrangement of prismatic plates of transient D019 and C-base centered orthorhombic phases precipitated in the α-Mg matrix during the T6 treatment. Both alloys prepared by powder metallurgy exhibit similar microstructure consisting of ∼ 4–6 μm α-Mg matrix fibers surrounded by particles of the equilibrium Mg5(Y, Nd) phase and of oxides. Open circuit potential and polarization resistance in the isotonic saline (9 g/l NaCl/H2O) were monitored for 24 h. The corrosion rate of the T4 and T6 treated alloys was about 80 times lower than that of commercial Mg. Both alloys prepared by powder metallurgy exhibited approximately 8 times higher corrosion resistance than commercial Mg. The human MG-63 osteoblast-like cells spreading and division in the extracts (0.28 g in 28 ml of EMEM) of all 4 alloys were monitored by cinemicrography for 24 h. The MG-63 cells proliferate without cytotoxicity in all extracts. - Highlights: ►T6 treated WE54 alloy exhibit dense triangular arrangement of β″ and β′ phase prismatic plates. ► Microstructure of PM prepared WE54 alloy consists of α-Mg phase cells surrounded by β phase particles. ► PM produced WE54 corroded 10 times faster in physiological solution thanT4 and T6 treated WE54. ► MG63 cell spreading in EMEM extracts of PM prepared WE54 is comparable to that in control EMEM. ► Cell mitosis is enhanced in PM WE54 extracts compared to the control and extracts of T4 and T6 WE54.

  4. Boron nitride nanotube reinforced polylactide-polycaprolactone copolymer composite: mechanical properties and cytocompatibility with osteoblasts and macrophages in vitro.

    Science.gov (United States)

    Lahiri, Debrupa; Rouzaud, Francois; Richard, Tanisha; Keshri, Anup K; Bakshi, Srinivasa R; Kos, Lidia; Agarwal, Arvind

    2010-09-01

    Biodegradable polylactide-polycaprolactone copolymer (PLC) has been reinforced with 0, 2 and 5wt.% boron nitride nanotubes (BNNTs) for orthopedic scaffold application. Elastic modulus of the PLC-5wt.% BNNT composite, evaluated through nanoindentation technique, shows a 1370% increase. The same amount of BNNT addition to PLC enhances the tensile strength by 109%, without any adverse effect on the ductility up to 240% elongation. Interactions of the osteoblasts and macrophages with bare BNNTs prove them to be non-cytotoxic. PLC-BNNT composites displayed increased osteoblast cell viability as compared to the PLC matrix. The addition of BNNTs also resulted in an increase in the expression levels of the Runx2 gene, the main regulator of osteoblast differentiation. These results indicate that BNNT is a potential reinforcement for composites for orthopedic applications. PMID:20226282

  5. Hepatic Bel-7402 Cell Proliferation on Different Phospholipid Surfaces

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    Phospholipids are believed to be important biomaterials.However, limited information is available on their cytocompatibilities.The objective of this study is to evaluate the effects of different phospholipids on the proliferation of hepatic Bel-7402 cells by comparing the adhesion, viability and proliferation of Bel-7402 cells cultured on different phospholipid surfaces.The cell adhesion, determined by counting the number of adhered cells to the surface, indicated that the cell adhesion was enhanced on charged phospolipid membranes.The cell viability evaluated by MTT[3 (4,5-dimethylthiazole-2-yl)-2,5-diphenyl tetrazolium-bromide] showed that cells cultured on charged phospholipids have greater viability than those cultured on the control, while cells cultured on neutral phospholipids showed lower viability.The cell cycle analysis using flow cytometry demonstrated that S phase entry increased on charged phospholipids, while S phase entry decreased on neutral phospholipids.The results suggested that charged phospholipids, especially positively charged phospholipids, show better cytocompatibilities than neutral phospholipids to hepatic Bel-7402 cell.

  6. Evaluation for cell affinity of the composite material containing carbon nanotubes

    Institute of Scientific and Technical Information of China (English)

    KANG Shizhao; WAN Yuqing; YAN Huijuan; BEI Jianzhong; WANG Chen; WANG Shenguo; WANG Chunru; WAN Lijun; BAI Chunli

    2004-01-01

    The composite material of poly-(L-lactide) (PLLA) and carbon nanotubes (CNTs) were prepared. Its surface morphologies and property were worked out by using atomic force microscopy (AFM) and contact angle measurement. Moreover, the prime cytocompatibility was used to investigate the biocompatibility of the composite material containing CNTs and the effects of CNTs on one aspect of cell function, cell affinity. The results obtained indicate that the composite material of PLLA and CNTs possesses good biocompatibility for both the 3T3 fibroblasts and Oct-1 osteoblast-like cells. The addition of CNTs will greatly affect cell affinity of the material, which may be disadvantage for the cell adhesion.

  7. Preliminary Investigation of the Dissolution Behavior, Cytocompatibility, Effects of Fibrinogen Conformation and Platelet Adhesion for Radiopaque Embolic Particles

    Directory of Open Access Journals (Sweden)

    Daniel Boyd

    2013-07-01

    Full Text Available Experimental embolic particles based on a novel zinc-silicate glass system have been biologically evaluated for potential consideration in transcatheter arterial embolization procedures. In addition to controlling the cytotoxicity and haemocompatibility for such embolic particles, its glass structure may mediate specific responses via dissolution in the physiological environment. In a 120 h in-vitro dissolution study, ion release levels for silicon (Si4+, sodium (Na+, calcium (Ca2+, zinc (Zn2+, titanium (Ti4+, lanthanum (La3+, strontium (Sr2+, and magnesium (Mg2+, were found to range from 0.04 to 5.41 ppm, 0.27–2.28 ppm, 2.32–8.47 ppm, 0.16–0.20 ppm, 0.12–2.15 ppm, 0.16–0.49 ppm and 0.01–0.12 ppm, respectively for the series of glass compositions evaluated. Initial release of Zn2+ (1.93–10.40 ppm was only evident after 120 h. All compositions showed levels of cell viabilities ranging from 61.31 ± 4.33% to 153.7 ± 1.25% at 25%–100% serial extract dilutions. The conformational state of fibrinogen, known to induce thrombi, indicated that no changes were induced with respect of the materials dissolution by-products. Furthermore, the best-in-class experimental composition showed equivalency to contour PVA in terms of inducing platelet adhesion. The data generated here provides requisite evidence to continue to in-vivo pre-clinical evaluation using the best-in-class experimental composition evaluated.

  8. Photoclick Hydrogels Prepared from Functionalized Cyclodextrin and Poly(ethylene glycol) for Drug Delivery and in Situ Cell Encapsulation.

    Science.gov (United States)

    Shih, Han; Lin, Chien-Chi

    2015-07-13

    Polymers or hydrogels containing modified cyclodextrin (CD) are highly useful in drug delivery applications, as CD is a cytocompatible amphiphilic molecule that can complex with a variety of hydrophobic drugs. Here, we designed modular photoclick thiol-ene hydrogels from derivatives of βCD and poly(ethylene glycol) (PEG), including βCD-allylether (βCD-AE), βCD-thiol (βCD-SH), PEG-thiol (PEGSH), and PEG-norbornene (PEGNB). Two types of CD-PEG hybrid hydrogels were prepared using radical-mediated thiol-ene photoclick reactions. Specifically, thiol-allylether hydrogels were formed by reacting multiarm PEGSH and βCD-AE, and thiol-norbornene hydrogels were formed by cross-linking βCD-SH and multiarm PEGNB. We characterized the properties of these two types of thiol-ene hydrogels, including gelation kinetics, gel fractions, hydrolytic stability, and cytocompatibility. Compared with thiol-allylether hydrogels, thiol-norbornene photoclick reaction formed hydrogels with faster gelation kinetics at equivalent macromer contents. Using curcumin, an anti-inflammatory and anticancer hydrophobic molecule, we demonstrated that CD-cross-linked PEG-based hydrogels, when compared with pure PEG-based hydrogels, afforded higher drug loading efficiency and prolonged delivery in vitro. Cytocompatibility of these CD-cross-linked hydrogels were evaluated by in situ encapsulation of radical sensitive pancreatic MIN6 β-cells. All formulations and cross-linking conditions tested were cytocompatible for cell encapsulation. Furthermore, hydrogels cross-linked by βCD-SH showed enhanced cell proliferation and insulin secretion as compared to gels cross-linked by either dithiothreitol (DTT) or βCD-AE, suggesting the profound impact of both macromer compositions and gelation chemistry on cell fate in chemically cross-linked hydrogels. PMID:25996903

  9. Mesenchymal Stem Cell Responses to Bone-Mimetic Electrospun Matrices Composed of Polycaprolactone, Collagen I and Nanoparticulate Hydroxyapatite

    OpenAIRE

    Phipps, Matthew C.; Clem, William C.; Catledge, Shane A.; Xu, Yuanyuan; Hennessy, Kristin M.; Thomas, Vinoy; Jablonsky, Michael J.; Chowdhury, Shafiul; Stanishevsky, Andrei V; Vohra, Yogesh K.; Susan L Bellis

    2011-01-01

    The performance of biomaterials designed for bone repair depends, in part, on the ability of the material to support the adhesion and survival of mesenchymal stem cells (MSCs). In this study, a nanofibrous bone-mimicking scaffold was electrospun from a mixture of polycaprolactone (PCL), collagen I, and hydroxyapatite (HA) nanoparticles with a dry weight ratio of 50/30/20 respectively (PCL/col/HA). The cytocompatibility of this tri-component scaffold was compared with three other scaffold form...

  10. Surface modification of PVDF using non-mammalian sources of collagen for enhancement of endothelial cell functionality

    OpenAIRE

    Wang, Jun Kit; Xiong, Gordon Minru; Luo, Baiwen; Choo, Chee Chong; Yuan, Shaojun; Tan, Nguan Soon; Choong, Cleo

    2016-01-01

    Although polyvinylidene fluoride (PVDF) is non-toxic and stable in vivo, its hydrophobic surface has limited its bio-applications due to poor cell-material interaction and thrombus formation when used in blood contacting devices. In this study, surface modification of PVDF using naturally derived non-mammalian collagen was accomplished via direct surface-initiated atom transfer radical polymerisation (SI-ATRP) to enhance its cytocompatibility and hemocompatibility. Results showed that Type I ...

  11. Synthesis of an AIE-active fluorogen and its application in cell imaging

    Institute of Scientific and Technical Information of China (English)

    LAM; Jacky; Wing; Yip; FAISAL; Mahtab; NG; Ka; Ming; LUO; Kathy; Qian

    2009-01-01

    A fluorogen named 1-decyl-1-methyl-2,5-bis{4-[(N,N-diethylamino)methyl]phenyl}-3,4-diphenylsilole (3) was synthesized. It emitted weakly as isolated molecule but strongly as supramolecular aggregate, showing a characteristic behavior of aggregation-induced emission (AIE). The molecules of 3 formed highly emissive nanoparticles in aqueous media, which quickly and selectively marked cytoplasm of HeLa cells and posed no toxicity to the living cells. The fluorogen is thus a promising candidate mate-rial for cell imaging as a sensitive, selective and cytocompatible biosensor.

  12. Biodegradable electrospun nanofibers coated with platelet-rich plasma for cell adhesion and proliferation

    OpenAIRE

    Díaz-Gómez, Luis; Alvarez-Lorenzo, Carmen; Concheiro, Angel; Silva, Maite; Dominguez, Fernando; Faheem A. Sheikh; Cantu, Travis; Desai, Raj; Garcia, Vanessa L.; Macossay, Javier

    2014-01-01

    Biodegradable electrospun poly(ε-caprolactone) (PCL) scaffolds were coated with platelet-rich plasma (PRP) to improve cell adhesion and proliferation. PRP was obtained from human buffy coat, and tested on human adipose-derived mesenchymal stem cells (MSC) to confirm cell proliferation and cytocompatibility. Then, PRP was adsorbed on the PCL scaffolds via lyophilization, which resulted in uniform sponge-like coating of 2.85 (s.d. 0.14) mg/mg. The scaffolds were evaluated regarding mechanical p...

  13. Modulation of stem cell differentiation by the influence of nanobiomaterials/carriers.

    Science.gov (United States)

    Bokara, Kiran Kumar; Oggu, Gopi Suresh; Vidyasagar, Aditya Josyula; Asthana, Amit; Lee, Jong Eun; Rao, Ch Mohan

    2014-01-01

    Stem cells, either neural [NSCs] or mesenchymal [MSCs], possess tremendous untapped potential for cell therapy. Unlike the NSCs, MSCs are multi-potent and they have high self-renewal capability and broad tissue distribution. Since they do not produce significant immune rejection on post-transplantation; they are better suited for cell-based therapies. However, several critical issues need to be addressed to maximize stem cell-derived therapeutic effects. The key factor affecting the therapeutic application of stem cells is exposure to hostile conditions in vivo such as oxidative stress, which results in considerably low survival rate of these cells at transplanted sites, thereby reducing the therapeutic efficiency. Such limitation has led scientists to design clinically relevant, innovative and multifaceted solutions including the use of nanobiomaterials. Use of cytocompatible nanobiomaterials holds great promise and has gained attention of researchers, worldwide. Various nanobiomaterials are being explored to increase the survival efficiency and direct differentiation of stem cells to generate tissue-specific cells for biomedical research and futuristic therapies. These materials have superior cytocompatability, mechanical, electrical, optical, catalytic and magnetic properties. Non-invasive visualization of the biological system has been developed using magnetic nanoparticles and magnetic resonance imaging [MRI] approaches. Apart from viral vectors, non-viral carriers such as DNA nano carriers, single stranded RNA nanoparticles, liposomes and carbon nanotubes/wires are being exploited for gene delivery into stem cells. This article reviews potential application of various biocompatible nanomaterials in stem cell research and development. PMID:25163795

  14. Chemical sporulation and germination: cytoprotective nanocoating of individual mammalian cells with a degradable tannic acid-FeIII complex

    Science.gov (United States)

    Lee, Juno; Cho, Hyeoncheol; Choi, Jinsu; Kim, Doyeon; Hong, Daewha; Park, Ji Hun; Yang, Sung Ho; Choi, Insung S.

    2015-11-01

    Individual mammalian cells were coated with cytoprotective and degradable films by cytocompatible processes maintaining the cell viability. Three types of mammalian cells (HeLa, NIH 3T3, and Jurkat cells) were coated with a metal-organic complex of tannic acid (TA) and ferric ion, and the TA-FeIII nanocoat effectively protected the coated mammalian cells against UV-C irradiation and a toxic compound. More importantly, the cell proliferation was controlled by programmed formation and degradation of the TA-FeIII nanocoat, mimicking the sporulation and germination processes found in nature.Individual mammalian cells were coated with cytoprotective and degradable films by cytocompatible processes maintaining the cell viability. Three types of mammalian cells (HeLa, NIH 3T3, and Jurkat cells) were coated with a metal-organic complex of tannic acid (TA) and ferric ion, and the TA-FeIII nanocoat effectively protected the coated mammalian cells against UV-C irradiation and a toxic compound. More importantly, the cell proliferation was controlled by programmed formation and degradation of the TA-FeIII nanocoat, mimicking the sporulation and germination processes found in nature. Electronic supplementary information (ESI) available: Experimental details, LSCM images, and SEM and TEM images. See DOI: 10.1039/c5nr05573c

  15. Bioprintable, cell-laden silk fibroin-gelatin hydrogel supporting multilineage differentiation of stem cells for fabrication of three-dimensional tissue constructs.

    Science.gov (United States)

    Das, Sanskrita; Pati, Falguni; Choi, Yeong-Jin; Rijal, Girdhari; Shim, Jin-Hyung; Kim, Sung Won; Ray, Alok R; Cho, Dong-Woo; Ghosh, Sourabh

    2015-01-01

    Bioprinting has exciting prospects for printing three-dimensional (3-D) tissue constructs by delivering living cells with appropriate matrix materials. However, progress in this field is currently extremely slow due to limited choices of bioink for cell encapsulation and cytocompatible gelation mechanisms. Here we report the development of clinically relevant sized tissue analogs by 3-D bioprinting, delivering human nasal inferior turbinate tissue-derived mesenchymal progenitor cells encapsulated in silk fibroin-gelatin (SF-G) bioink. Gelation in this bioink was induced via in situ cytocompatible gelation mechanisms, namely enzymatic crosslinking by mushroom tyrosinase and physical crosslinking via sonication. Mechanistically, tyrosinases oxidize the accessible tyrosine residues of silk and/or gelatin into reactive o-quinone moieties that can either condense with each other or undergo nonenzymatic reactions with available amines of both silk and gelatin. Sonication alters the hydrophobic interaction and accelerates self-assembly of silk fibroin macromolecules to form β-sheet crystals, which physically crosslink the hydrogel. However, sonication has no effect on the conformation of gelatin. The effect of optimized rheology, secondary conformations of silk-gelatin bioink, temporally controllable gelation strategies and printing parameters were assessed to achieve maximum cell viability and multilineage differentiation of the encapsulated human nasal inferior turbinate tissue-derived mesenchymal progenitor cells. This strategy offers a unique path forward in the direction of direct printing of spatially customized anatomical architecture in a patient-specific manner. PMID:25242654

  16. Cell proliferation, viability, and in vitro differentiation of equine mesenchymal stem cells seeded on bacterial cellulose hydrogel scaffolds

    Energy Technology Data Exchange (ETDEWEB)

    Favi, Pelagie M.; Benson, Roberto S. [Department of Materials Science and Engineering, College of Engineering, University of Tennessee, Knoxville, TN 37996 (United States); Neilsen, Nancy R. [Department of Biomedical and Diagnostic Sciences, College of Veterinary Medicine, University of Tennessee, Knoxville, TN 37996 (United States); Hammonds, Ryan L. [Department of Materials Science and Engineering, College of Engineering, University of Tennessee, Knoxville, TN 37996 (United States); Bates, Cassandra C. [Department of Large Animal Clinical Sciences, College of Veterinary Medicine, University of Tennessee, Knoxville, TN 37996 (United States); Stephens, Christopher P. [Department of Surgery, Graduate School of Medicine, University of Tennessee, Knoxville, TN 37996 (United States); Center for Materials Processing, University of Tennessee, Knoxville, TN 37996 (United States); Dhar, Madhu S., E-mail: mdhar@utk.edu [Department of Large Animal Clinical Sciences, College of Veterinary Medicine, University of Tennessee, Knoxville, TN 37996 (United States)

    2013-05-01

    The culture of multipotent mesenchymal stem cells on natural biopolymers holds great promise for treatments of connective tissue disorders such as osteoarthritis. The safety and performance of such therapies relies on the systematic in vitro evaluation of the developed stem cell-biomaterial constructs prior to in vivo implantation. This study evaluates bacterial cellulose (BC), a biocompatible natural polymer, as a scaffold for equine-derived bone marrow mesenchymal stem cells (EqMSCs) for application in bone and cartilage tissue engineering. An equine model was chosen due to similarities in size, load and types of joint injuries suffered by horses and humans. Lyophilized and critical point dried BC hydrogel scaffolds were characterized using scanning electron microscopy (SEM) to confirm nanostructure morphology which demonstrated that critical point drying induces fibre bundling unlike lyophilisation. EqMSCs positively expressed the undifferentiated pluripotent mesenchymal stem cell surface markers CD44 and CD90. The BC scaffolds were shown to be cytocompatible, supporting cellular adhesion and proliferation, and allowed for osteogenic and chondrogenic differentiation of EqMSCs. The cells seeded on the BC hydrogel were shown to be viable and metabolically active. These findings demonstrate that the combination of a BC hydrogel and EqMSCs are promising constructs for musculoskeletal tissue engineering applications. - Highlights: ► Critical point drying induces fibre bundling unlike lyophilisation. ► Cells positively expressed undifferentiated pluripotent stem cell markers. ► BCs were cytocompatible, supported cell adhesion, proliferation and differentiation ► Cells seeded on BC scaffolds were viable and metabolically active. ► Findings demonstrate that BC and EqMSCs are promising tissue engineered constructs.

  17. Cell proliferation, viability, and in vitro differentiation of equine mesenchymal stem cells seeded on bacterial cellulose hydrogel scaffolds

    International Nuclear Information System (INIS)

    The culture of multipotent mesenchymal stem cells on natural biopolymers holds great promise for treatments of connective tissue disorders such as osteoarthritis. The safety and performance of such therapies relies on the systematic in vitro evaluation of the developed stem cell-biomaterial constructs prior to in vivo implantation. This study evaluates bacterial cellulose (BC), a biocompatible natural polymer, as a scaffold for equine-derived bone marrow mesenchymal stem cells (EqMSCs) for application in bone and cartilage tissue engineering. An equine model was chosen due to similarities in size, load and types of joint injuries suffered by horses and humans. Lyophilized and critical point dried BC hydrogel scaffolds were characterized using scanning electron microscopy (SEM) to confirm nanostructure morphology which demonstrated that critical point drying induces fibre bundling unlike lyophilisation. EqMSCs positively expressed the undifferentiated pluripotent mesenchymal stem cell surface markers CD44 and CD90. The BC scaffolds were shown to be cytocompatible, supporting cellular adhesion and proliferation, and allowed for osteogenic and chondrogenic differentiation of EqMSCs. The cells seeded on the BC hydrogel were shown to be viable and metabolically active. These findings demonstrate that the combination of a BC hydrogel and EqMSCs are promising constructs for musculoskeletal tissue engineering applications. - Highlights: ► Critical point drying induces fibre bundling unlike lyophilisation. ► Cells positively expressed undifferentiated pluripotent stem cell markers. ► BCs were cytocompatible, supported cell adhesion, proliferation and differentiation ► Cells seeded on BC scaffolds were viable and metabolically active. ► Findings demonstrate that BC and EqMSCs are promising tissue engineered constructs

  18. Data describing the swelling behavior and cytocompatibility of biodegradable polyelectrolyte hydrogels incorporating poly(L-lysine) for applications in cartilage tissue engineering.

    Science.gov (United States)

    Lam, Johnny; Clark, Elisa C; Fong, Eliza L S; Lee, Esther J; Lu, Steven; Tabata, Yasuhiko; Mikos, Antonios G

    2016-06-01

    This data article presents data associated with the research article entitled "Evaluation of cell-laden polyelectrolyte hydrogels incorporating poly(L-lysine) for applications in cartilage tissue engineering" (Lam et al., 2016) [1]. Synthetic hydrogel composites fabricated using oligo(poly(ethylene glycol) fumarate) (OPF) macromers were utilized as vehicles for the incorporation of poly(L-lysine) (PLL) as well as the encapsulation of mesenchymal stem cells (MSCs). PLL-laden and PLL-free hydrogels were fabricated to characterize the main and interaction effects of OPF molecular weight, PLL molecular weight, and PLL loading density on the swelling and degradation of synthetic OPF hydrogels. Cells were then encapsulated within such hydrogels for in vitro culture and examined for viability, biochemical activity, and chondrogenic gene expression. These data, which are supplementary to the associated research article (Lam et al., 2016) [1], are presented here. PMID:27054167

  19. Biocorrosion behavior and cell viability of adhesive polymer coated magnesium based alloys for medical implants

    International Nuclear Information System (INIS)

    Highlights: ► The corrosion behavior of magnesium for orthopedic applications is extremely poor. ► The solvent (DCM, THF and DMF) had a strong effect on the coatings performance. ► Mg bar alloy coated with PVAc/DCM layers provided an excellent bonding strength. ► Treated samples indicated significant damping for the degradation rate. ► Cytocompatibility on MC3T3 cells of the PVAc/DCM samples revealed a good behavior. - Abstract: The present study was ultimately aimed to design novel adhesive biodegradable polymer, poly(vinyl acetate) (PVAc), coatings onto Mg based alloys by the dip-coating technique in order to control the degradation rate and enhance the biocompatibility of magnesium alloys. The influence of various solvents on PVAc surface topography and their protection of Mg alloys were dramatically studied in vitro. Electrochemical polarization, degradation, and PVAc film cytocompatibility were also tested. Our results showed that the solvent had a significant effect on coating quality. PVAc/dichloromethane solution showed a porous structure and solution concentration could control the porous size. The coatings prepared using tetrahydrofuran and dimethylformamide solvents are exceptional in their ability to generate porous morphology even at low polymer concentration. In general, the corrosion performance appears to be different on different PVAc–solvent system. Immersion tests illustrated that the porous morphology on PVAc stabilized corrosion rates. A uniform corrosion attack in artificial simulation body fluid was also exhibited. The cytocompatibility of osteoblast cells (MC3T3) revealed high adherence, proliferation, and survival on the porous structure of PVAc coated Mg alloy, which was not observed for the uncoated samples. This novel PVAc coating is a promising candidate for biodegradable implant materials, which might widen the use of Mg based implants.

  20. Biocorrosion behavior and cell viability of adhesive polymer coated magnesium based alloys for medical implants

    Energy Technology Data Exchange (ETDEWEB)

    Abdal-hay, Abdalla [Departmentt of Bionano System Engineering, College of Engineering, Chonbuk National University, Jeonju 561-756 (Korea, Republic of); Department of Mechanical Design Engineering, Advanced wind power system research institute, Chonbuk National University, Jeonju 561-756 (Korea, Republic of); Dewidar, Montasser [Department of Materials and Mechanical Design, Faculty of Energy Engineering, South Valley University, Aswan (Egypt); Lim, Jae Kyoo, E-mail: jklim@jbnu.ac.kr [Department of Mechanical Design Engineering, Advanced wind power system research institute, Chonbuk National University, Jeonju 561-756 (Korea, Republic of)

    2012-11-15

    Highlights: Black-Right-Pointing-Pointer The corrosion behavior of magnesium for orthopedic applications is extremely poor. Black-Right-Pointing-Pointer The solvent (DCM, THF and DMF) had a strong effect on the coatings performance. Black-Right-Pointing-Pointer Mg bar alloy coated with PVAc/DCM layers provided an excellent bonding strength. Black-Right-Pointing-Pointer Treated samples indicated significant damping for the degradation rate. Black-Right-Pointing-Pointer Cytocompatibility on MC3T3 cells of the PVAc/DCM samples revealed a good behavior. - Abstract: The present study was ultimately aimed to design novel adhesive biodegradable polymer, poly(vinyl acetate) (PVAc), coatings onto Mg based alloys by the dip-coating technique in order to control the degradation rate and enhance the biocompatibility of magnesium alloys. The influence of various solvents on PVAc surface topography and their protection of Mg alloys were dramatically studied in vitro. Electrochemical polarization, degradation, and PVAc film cytocompatibility were also tested. Our results showed that the solvent had a significant effect on coating quality. PVAc/dichloromethane solution showed a porous structure and solution concentration could control the porous size. The coatings prepared using tetrahydrofuran and dimethylformamide solvents are exceptional in their ability to generate porous morphology even at low polymer concentration. In general, the corrosion performance appears to be different on different PVAc-solvent system. Immersion tests illustrated that the porous morphology on PVAc stabilized corrosion rates. A uniform corrosion attack in artificial simulation body fluid was also exhibited. The cytocompatibility of osteoblast cells (MC3T3) revealed high adherence, proliferation, and survival on the porous structure of PVAc coated Mg alloy, which was not observed for the uncoated samples. This novel PVAc coating is a promising candidate for biodegradable implant materials, which might

  1. 3D patterned stem cell differentiation using thermo-responsive methylcellulose hydrogel molds

    Science.gov (United States)

    Lee, Wonjae; Park, Jon

    2016-07-01

    Tissue-specific patterned stem cell differentiation serves as the basis for the development, remodeling, and regeneration of the multicellular structure of the native tissues. We herein proposed a cytocompatible 3D casting process to recapitulate this patterned stem cell differentiation for reconstructing multicellular tissues in vitro. We first reconstituted the 2D culture conditions for stem cell fate control within 3D hydrogel by incorporating the sets of the diffusible signal molecules delivered through drug-releasing microparticles. Then, utilizing thermo-responsivity of methylcellulose (MC), we developed a cytocompatible casting process to mold these hydrogels into specific 3D configurations, generating the targeted spatial gradients of diffusible signal molecules. The liquid phase of the MC solution was viscous enough to adopt the shapes of 3D impression patterns, while the gelated MC served as a reliable mold for patterning the hydrogel prepolymers. When these patterned hydrogels were integrated together, the stem cells in each hydrogel distinctly differentiated toward individually defined fates, resulting in the formation of the multicellular tissue structure bearing the very structural integrity and characteristics as seen in vascularized bones and osteochondral tissues.

  2. 3D patterned stem cell differentiation using thermo-responsive methylcellulose hydrogel molds

    Science.gov (United States)

    Lee, Wonjae; Park, Jon

    2016-01-01

    Tissue-specific patterned stem cell differentiation serves as the basis for the development, remodeling, and regeneration of the multicellular structure of the native tissues. We herein proposed a cytocompatible 3D casting process to recapitulate this patterned stem cell differentiation for reconstructing multicellular tissues in vitro. We first reconstituted the 2D culture conditions for stem cell fate control within 3D hydrogel by incorporating the sets of the diffusible signal molecules delivered through drug-releasing microparticles. Then, utilizing thermo-responsivity of methylcellulose (MC), we developed a cytocompatible casting process to mold these hydrogels into specific 3D configurations, generating the targeted spatial gradients of diffusible signal molecules. The liquid phase of the MC solution was viscous enough to adopt the shapes of 3D impression patterns, while the gelated MC served as a reliable mold for patterning the hydrogel prepolymers. When these patterned hydrogels were integrated together, the stem cells in each hydrogel distinctly differentiated toward individually defined fates, resulting in the formation of the multicellular tissue structure bearing the very structural integrity and characteristics as seen in vascularized bones and osteochondral tissues. PMID:27381562

  3. Ractopamine up take by alfalfa (Medicago sativa) and wheat (Triticum aestivum) from soil.

    Science.gov (United States)

    Shelver, Weilin L; DeSutter, Thomas M

    2015-08-01

    Ractopamine is a beta adrenergic agonist used as a growth promoter in swine, cattle and turkeys. To test whether ractopamine has the potential to accumulate in plants grown in contaminated soil, a greenhouse study was conducted with alfalfa (Medicago sativa) and wheat (Triticum aestivum) grown in two soils having different concentrations of organic matter (1.3% and 2.1%), amended with 0, 0.5, and 10 μg/g of ractopamine. Plant growth ranged from 2.7 to 8.8 g dry weight (dw) for alfalfa, and 8.7 to 40 g dw for wheat and was generally greater in the higher organic matter content soil. The uptake of ractopamine in plant tissues ranged from non-detectable to 897 ng/g and was strongly dependent on soil ractopamine concentration across soil and plant tissue. When adjusted to the total fortified quantities, the amount of ractopamine taken up by the plant tissue was low, <0.01% for either soil. PMID:26257350

  4. Use of the methylcellulose gum for fat up-take absorption in coated products

    Directory of Open Access Journals (Sweden)

    Daniele Domingues Dill

    2008-08-01

    Full Text Available Even though coated meats have added value to products and gained consumers confidence, by improving these product’s appearance and taste, they go through a pre-frying stage during processing which releases the water and allows fat to enter the product, thus increasing fat content. The purpose of this work was to develop a coating system that absorbs less fat during the pre-frying stage of a chicken coated product. To do that, methylcellulose gum was added (MC in different concentrations in the covering systems, batter (coating liquid and breading (covering expresses. Five experiments were carried out, a standard experiment, without ingredient addition with technological function, formulations with addition of MC in the batter (0,5% and 2,0%, with addition of MC in the batter and in the breading (1% in each and with addition of MC in the breading (2,0%. Results showed that fat uptake reduction in formulations with 0,5 and 2,0% of MC in the batter were of 5,81% and 8,40%, respectively, and in experiments with 1% of MC in the batter and 1% of MC in the breading was of 7,66%. In experiments that received 2% of MC in the breading , fat uptake reduction was of 10,51%. Formulations with 2% of MC added to the breading (10,51% and 2% of MC added to the batter (8,40% presented the largest reductions in fat uptake during the pre-fried stage. Analysis of sensorial acceptance showed that all formulations had a superior acceptance index of 70%, with no significant difference among the other tested formulations acceptance results (p <0,05. These findings show the efficiency of MC as a fat uptake barrier during the pre-fried stage, increasing humidity content, and becoming an advantageous technological alternative for the food industry.

  5. Fabrication of Larynx-Shape Porous PHBHH for Cartilage Tissue Engineering and the Cytocompatibility with Chondrocytes%组织工程PHBHH多孔材料喉支架的制备与细胞相容性研究

    Institute of Scientific and Technical Information of China (English)

    孙安科; 胡平; 李万同; 孟庆延; 陈伟; 唐维维

    2011-01-01

    Objective To explore the possibility of using [poly(3 - hydroxybutyrate - co - 3- hydroxy-hexanoate) ,PHBHH] as biomaterials for cartilage tissue engineering of larynx and observe the cytocompatibility between PHBHH and chondrocytes. Methods Larynx-shape porous PHBHH models was fabricated by means of solvent casting,compression molding and paniculate leaching techniques; and the porosity of PHBHH was measured by liquid (alcohol) replacement. The larynx-shape PHBHH models were evaluated by morphological observation. PHBHH porousness, and the attachment, growth condition and distribution between PHBHH and chondrocytes were evaluated by morphological observation and scanning electron microscopy. Results Larynx-shape porous PHBHH models with edges and corners of laryngeal cartilage appeared to be hollow half-trumpet shape and its porosity was 92%±2%. The porous PHBHH looked like netwok. The chondrocytes equallyl attached to the surface of porous PHBHH, filled within porousness, and secrected a large quantity of extracellular matrix, Conclusion Porous PHBHH may be used as biomaterials to fabricate larynx-shape tissue engineering models with suitable mechan-ical support and porosity, and had good cytocompatibility with chondrocytes in vitro.%目的 探索组织工程多孔生物材料喉支架形态塑形物的制备技术,体外观察其细胞相容性,为进一步探寻软骨组织工程适宜生物材料提供实验依据.方法 以新型生物材料聚羟基丁酸酯与聚羟基己酸酯共聚物[ poly(3-hydroxybutyrate- co-3- hydroxyhexanoate),PHBHH,M=60万]为原料,氯化钠盐粒为致孔剂,采用溶剂浇铸、模压成形和颗粒滤沥技术制备多孔PHBHH喉支架形态塑形物,以乙醇置换法测定其孔隙率,负载软骨细胞后体外共同培养,通过大体形态、扫描电镜观察材料模压成形效果、材料孔隙连续性及其与软骨细胞粘附、分布和生长情况.结果 模压成形的组织工程PHBHH材料塑形物类似喉

  6. Fabrication and cyto-compatibility of Fe3O4/SiO2/graphene-CdTe QDs/CS nanocomposites for drug delivery.

    Science.gov (United States)

    Ou, Jun; Wang, Fang; Huang, Yuanjie; Li, Duosheng; Jiang, Yuming; Qin, Qing-Hua; Stachurski, Z H; Tricoli, Antonio; Zhang, Tina

    2014-05-01

    Synthesis of magnetic Fe3O4/SiO2/graphene-CdTe QDs/chitosan nanocomposites (FGQCs) is investigated with respect to their potential of improving the drug loading content above that of magnetic/fluorescent bifunctional nanocomposites. To evaluate the performance of the FGQCs, their surface morphology was thoroughly assessed. The in vitro interaction between the FGQCs and heptoma cell line smmc-7721 cells was observed for the first time by TEM ultrathin section imaging. At an excitation wavelength of 365 nm, the graphene-QDs exhibit a strong luminescence in aqueous environments. The loading content and entrapment efficiency of the FGQCs were 70% and 50%, respectively. The cytotoxicity of this novel drug delivery system was evaluated in vitro using heptoma cell line smmc-7721 and quantified by the 3-(4,5-dimethylthiazol-z-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The results show that FGQCs are a promising new multifunctional material for drug delivery in biological and medical applications. PMID:24373978

  7. Evaluation of the Cytocompatibility of Bacterial Cellulose Nanomaterial%细菌纤维素纳米纤维的细胞相容性评价

    Institute of Scientific and Technical Information of China (English)

    杨光; 王彩霞; 杨雪霞

    2012-01-01

    Bacterial cellulose is a kind of natural nanomaterial, and has been widely used in tissue engineering applications. In this work, the cycocompatibility of pure bacterial cellulose (BC) and bacterial cellulose/polyacrylamide (BC/PAM), a double-network (DN) hydrogel material, was evaluated using fibroblast L929 and vascular endothelial cell. SEM was used to demonstrate the cell growing morphology. The proliferation situation of both cells was assayed by MTT. The results turned out that vascular endothelial cell was good on the pure BC material in terms of high proliferation and well-spread morphology, while fibroblast L929 showed a poor proliferation action on both the pure BC and BC/PAM composite.%细菌纤维素是一种天然的纳米纤维材料,在组织工程材料领域具有广阔的应用前景。在前期研究的基础上,以细菌纤维素(Bc)及细菌纤维素/聚丙烯酰胺双网络水凝胶(BC/PAM)复合材料为研究对象,大鼠成纤维细胞L929及血管内皮细胞为细胞模型,采用扫描电子显微镜观察细胞在材料上的黏附形态,并通过MTT法对细胞的增殖行为进行评价,以此考察BC及BC/PAM复合材料的细胞相容性,初步评价上述纳米纤维作为组织工程材料的应用可能性。结果表明,内皮细胞在纯BC材料上表现出良好的黏附形态和增殖行为,而成纤维细胞在纯BC及BC/PAM复合材料上的增殖趋势均低于空白对照组。

  8. In vitro hemocompatibility and cytocompatibility of a three-layered vascular scaffold fabricated by sequential electrospinning of PCL, collagen, and PLLA nanofibers.

    Science.gov (United States)

    Haghjooy Javanmard, Shaghayegh; Anari, Jamal; Zargar Kharazi, Anousheh; Vatankhah, Elham

    2016-09-01

    Aiming to mimic a blood vessel structurally, morphologically, and mechanically, a sequential electrospinning technique using a small diameter mandrel collector was performed and a three-layered tubular scaffold composed of nanofibers of polycaprolactone, collagen, and poly(l-lactic acid) as inner, intermediate, and outer layers, respectively, was developed. Biological performances of the scaffold in terms of compatibility with blood and endothelial cells were assessed to get some insights into its potential use as a tissue engineered small-diameter vascular replacement compared to an expanded polytetrafluoroethylene vascular graft. Due to direct contact of the blood and endothelial cells with inner surface of the scaffold, polycaprolactone fibers were characterized using SEM, water contact angle measurement, and ATR-FTIR. Despite similar surface wettability of the electrospun scaffold and the expanded polytetrafluoroethylene graft, the three-layered scaffold significantly reduced platelet adhesion and hemolysis ratio compared to expanded polytetrafluoroethylene graft while comparable blood clotting profiles were observed for both electrospun scaffold and expanded polytetrafluoroethylene graft. However, inflammatory response to nanofibrous surface of the scaffold was reduced compared to expanded polytetrafluoroethylene graft. The electrospun scaffold also presented a significantly more supportive substrate for endothelialization than the expanded polytetrafluoroethylene graft. The results described herein suggested that the three-layered scaffold has superior biological properties compared to an expanded polytetrafluoroethylene graft for vascular tissue engineering. PMID:27247131

  9. The effect of modified polysialic acid based hydrogels on the adhesion and viability of primary neurons and glial cells.

    Science.gov (United States)

    Haile, Yohannes; Berski, Silke; Dräger, Gerald; Nobre, Andrè; Stummeyer, Katharina; Gerardy-Schahn, Rita; Grothe, Claudia

    2008-04-01

    In this study we present the enzymatic and biological analysis of polysialic acid (polySia) based hydrogel in terms of its degradation and cytocompatibility. PolySia based hydrogel is completely degradable by endosialidase enzyme which may avoid second surgery after tissue recovery. Viability assay showed that soluble components of polySia hydrogel did not cause any toxic effect on cultured Schwann cells. Moreover, green fluorescence protein transfected neonatal and adult Schwann cells, neural stem cells and dorsal root ganglionic cells (unlabelled) were seeded on polySia hydrogel modified with poly-L-lysine (Pll), poly-L-ornithine-laminin (porn-laminin) or collagen. Water soluble tetrazolium salt assay revealed that modification of the hydrogel significantly improved cell adhesion and viability. These results infer that polySia based scaffolds in combination with cell adhesion molecules and cells genetically modified to express growth factors would potentially be promising alternative in reconstructive therapeutic strategies. PMID:18255143

  10. Collagen-IV supported embryoid bodies formation and differentiation from buffalo (Bubalus bubalis) embryonic stem cells

    International Nuclear Information System (INIS)

    Graphical abstract: EBs formation, characterization and expression of germinal layers marker genes of in vivo developed teratoma using four different types of extracellular matrices. Highlights: ► Collagen-IV matrix is found cytocompatible for EBs formation and differentiation. ► Established 3D microenvironment for ES cells development and differentiation into three germ layers. ► Collagen-IV may be useful as promising candidate for ES cells based therapeutic applications. -- Abstract: Embryoid bodies (EBs) are used as in vitro model to study early extraembryonic tissue formation and differentiation. In this study, a novel method using three dimensional extracellular matrices for in vitro generation of EBs from buffalo embryonic stem (ES) cells and its differentiation potential by teratoma formation was successfully established. In vitro derived inner cell masses (ICMs) of hatched buffalo blastocyst were cultured on buffalo fetal fibroblast feeder layer for primary cell colony formation. For generation of EBs, pluripotent ES cells were seeded onto four different types of extracellular matrices viz; collagen-IV, laminin, fibronectin and matrigel using undifferentiating ES cell culture medium. After 5 days of culture, ESCs gradually grew into aggregates and formed simple EBs having circular structures. Twenty-six days later, they formed cystic EBs over collagen matrix with higher EBs formation and greater proliferation rate as compared to other extracellular matrices. Studies involving histological observations, fluorescence microscopy and RT-PCR analysis of the in vivo developed teratoma revealed that presence of all the three germ layer derivatives viz. ectoderm (NCAM), mesoderm (Flk-1) and endoderm (AFP). In conclusion, the method described here demonstrates a simple and cost-effective way of generating EBs from buffalo ES cells. Collagen-IV matrix was found cytocompatible as it supported buffalo EBs formation, their subsequent differentiation could prove to

  11. Collagen-IV supported embryoid bodies formation and differentiation from buffalo (Bubalus bubalis) embryonic stem cells

    Energy Technology Data Exchange (ETDEWEB)

    Taru Sharma, G., E-mail: gts553@gmail.com [Reproductive Physiology Laboratory, Division of Physiology and Climatology, Indian Veterinary Research Institute, Izatnagar-243 122, Bareilly, U.P. (India); Dubey, Pawan K.; Verma, Om Prakash; Pratheesh, M.D.; Nath, Amar; Sai Kumar, G. [Reproductive Physiology Laboratory, Division of Physiology and Climatology, Indian Veterinary Research Institute, Izatnagar-243 122, Bareilly, U.P. (India)

    2012-08-03

    Graphical abstract: EBs formation, characterization and expression of germinal layers marker genes of in vivo developed teratoma using four different types of extracellular matrices. Highlights: Black-Right-Pointing-Pointer Collagen-IV matrix is found cytocompatible for EBs formation and differentiation. Black-Right-Pointing-Pointer Established 3D microenvironment for ES cells development and differentiation into three germ layers. Black-Right-Pointing-Pointer Collagen-IV may be useful as promising candidate for ES cells based therapeutic applications. -- Abstract: Embryoid bodies (EBs) are used as in vitro model to study early extraembryonic tissue formation and differentiation. In this study, a novel method using three dimensional extracellular matrices for in vitro generation of EBs from buffalo embryonic stem (ES) cells and its differentiation potential by teratoma formation was successfully established. In vitro derived inner cell masses (ICMs) of hatched buffalo blastocyst were cultured on buffalo fetal fibroblast feeder layer for primary cell colony formation. For generation of EBs, pluripotent ES cells were seeded onto four different types of extracellular matrices viz; collagen-IV, laminin, fibronectin and matrigel using undifferentiating ES cell culture medium. After 5 days of culture, ESCs gradually grew into aggregates and formed simple EBs having circular structures. Twenty-six days later, they formed cystic EBs over collagen matrix with higher EBs formation and greater proliferation rate as compared to other extracellular matrices. Studies involving histological observations, fluorescence microscopy and RT-PCR analysis of the in vivo developed teratoma revealed that presence of all the three germ layer derivatives viz. ectoderm (NCAM), mesoderm (Flk-1) and endoderm (AFP). In conclusion, the method described here demonstrates a simple and cost-effective way of generating EBs from buffalo ES cells. Collagen-IV matrix was found cytocompatible as it

  12. Biocorrosion behavior and cell viability of adhesive polymer coated magnesium based alloys for medical implants

    Science.gov (United States)

    Abdal-hay, Abdalla; Dewidar, Montasser; Lim, Jae Kyoo

    2012-11-01

    The present study was ultimately aimed to design novel adhesive biodegradable polymer, poly(vinyl acetate) (PVAc), coatings onto Mg based alloys by the dip-coating technique in order to control the degradation rate and enhance the biocompatibility of magnesium alloys. The influence of various solvents on PVAc surface topography and their protection of Mg alloys were dramatically studied in vitro. Electrochemical polarization, degradation, and PVAc film cytocompatibility were also tested. Our results showed that the solvent had a significant effect on coating quality. PVAc/dichloromethane solution showed a porous structure and solution concentration could control the porous size. The coatings prepared using tetrahydrofuran and dimethylformamide solvents are exceptional in their ability to generate porous morphology even at low polymer concentration. In general, the corrosion performance appears to be different on different PVAc-solvent system. Immersion tests illustrated that the porous morphology on PVAc stabilized corrosion rates. A uniform corrosion attack in artificial simulation body fluid was also exhibited. The cytocompatibility of osteoblast cells (MC3T3) revealed high adherence, proliferation, and survival on the porous structure of PVAc coated Mg alloy, which was not observed for the uncoated samples. This novel PVAc coating is a promising candidate for biodegradable implant materials, which might widen the use of Mg based implants.

  13. Surface characteristics of and in vitro behavior of osteoblast-like cells on titanium with nanotopography prepared by high-energy shot peening

    Directory of Open Access Journals (Sweden)

    Deng Z

    2014-11-01

    Full Text Available Zhennan Deng,1,2 Baodi Yin,1 Weihong Li,1 Jinsong Liu,1 Jingyuan Yang,1 Tieli Zheng,1 Dafeng Zhang,1 Haiyang Yu,2 Xiaoguang Liu,3 Jianfeng Ma1 1School and Hospital of Stomatology, Wenzhou Medical University, Wenzhou, Zhejiang, People’s Republic of China; 2State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, 3National Engineering Research Center for Biomaterials, Sichuan University, Chengdu, Sichuan, People’s Republic of China Background and methods: Commercial pure titanium with nanotopography was prepared via a high-energy shot-peening (HESP technique. The surface characteristics were evaluated, and the preliminary cell responses to the nanotopographical surface were investigated.Results: The nanotopographical surface layer on titanium was successfully processed by HESP. The average nanoscale grains were approximately 60 nm in diameter and they were nonhomogeneously distributed on the surface. MG-63 cells with an osteogenic phenotype were well adhered and well spread on the nanostructured surface. Compared to the original polished control, the nanotopographical surface highly improved the adhesion, viability, and differentiation of MG-63 cells.Conclusion: Titanium with nanotopography achieved by HESP has good cytocompatibility and shows promise for dental implant applications. Keywords: nanotopography, cytocompatibility, titanium, high-energy shot peening

  14. In vitro behavior of human osteoblast-like cells (SaOS2) cultured on surface modified titanium and titanium-zirconium alloy

    International Nuclear Information System (INIS)

    In this study, titanium (Ti) and titanium-zirconium (TiZr) alloy samples fabricated through powder metallurgy were surface modified by alkali-heat treatment and calcium (Ca)-ion-deposition. The alteration of the surface morphology and the chemistry of the Ti and TiZr after surface modification were examined. The bioactivity of the Ti and TiZr alloys after the surface modification was demonstrated. Subsequently, the cytocompatibility of the surface modified Ti and TiZr was evaluated via in vitro cell culture using human osteoblast-like cells (SaOS2). The cellular attachment, adhesion and proliferation after cell culture for 14 days were characterized by scanning electron microscopy (SEM) and MTT assay. The relationship between surface morphology and chemical composition of the surface modified Ti and TiZr and cellular responses was investigated. Results indicated that the surface-modified Ti and TiZr alloys exhibited excellent in vitro cytocompatibility together with satisfactory bioactivity. Since osteoblast adhesion and proliferation are essential prerequisites for a successful implant in vivo, these results provide evidence that Ti and TiZr alloys after appropriate surface modification are promising biomaterials for hard tissue replacement. Highlights: → Titanium (Ti) and titanium-zirconium (TiZr) alloy for load-bearing implant applications. → Implant applications. → Alkali-heat treatment and calcium (Ca)-ion-deposition as surface modification methods. → Surface modified Ti and TiZr exhibited excellent biocompatibility and bioactivity.

  15. Nafion and modified-Nafion membranes for polymer electrolyte fuel cells: An overview

    Indian Academy of Sciences (India)

    A K Sahu; S Pitchumani; P Sridhar; A K Shukla

    2009-06-01

    Polymer electrolyte fuel cells (PEFCs) employ membrane electrolytes for proton transport during the cell reaction. The membrane forms a key component of the PEFC and its performance is controlled by several physical parameters, viz. water up-take, ion-exchange capacity, proton conductivity and humidity. The article presents an overview on Nafion membranes highlighting their merits and demerits with efforts on modified-Nafion membranes.

  16. Modulation of Protein Adsorption and Cell Proliferation on Polyethylene Immobilized Graphene Oxide Reinforced HDPE Bionanocomposites.

    Science.gov (United States)

    Upadhyay, Rahul; Naskar, Sharmistha; Bhaskar, Nitu; Bose, Suryasarathi; Basu, Bikramjit

    2016-05-18

    The uniform dispersion of nanoparticles in a polymer matrix, together with an enhancement of interfacial adhesion is indispensable toward achieving better mechanical properties in the nanocomposites. In the context to biomedical applications, the type and amount of nanoparticles can potentially influence the biocompatibility. To address these issues, we prepared high-density polyethylene (HDPE) based composites reinforced with graphene oxide (GO) by melt mixing followed by compression molding. In an attempt to tailor the dispersion and to improve the interfacial adhesion, we immobilized polyethylene (PE) onto GO sheets by nucleophilic addition-elimination reaction. A good combination of yield strength (ca. 20 MPa), elastic modulus (ca. 600 MPa), and an outstanding elongation at failure (ca. 70%) were recorded with 3 wt % polyethylene grafted graphene oxide (PE-g-GO) reinforced HDPE composites. Considering the relevance of protein adsorption as a biophysical precursor to cell adhesion, the protein adsorption isotherms of bovine serum albumin (BSA) were determined to realize three times higher equilibrium constant (Keq) for PE-g-GO-reinforced HDPE composites as compared to GO-reinforced composites. To assess the cytocompatibility, we grew osteoblast cell line (MC3T3) and human mesenchymal stem cells (hMSCs) on HDPE/GO and HDPE/PE-g-GO composites, in vitro. The statistically significant increase in metabolically active cell over different time periods in culture for up to 6 days in MC3T3 and 7 days for hMSCs was observed, irrespective of the substrate composition. Such observation indicated that HDPE with GO or PE-g-GO addition (up to 3 wt %) can be used as cell growth substrate. The extensive proliferation of cells with oriented growth pattern also supported the fact that tailored GO addition can support cellular functionality in vitro. Taken together, the experimental results suggest that the PE-g-GO in HDPE can effectively be utilized to enhance both mechanical and

  17. Biophysical response of living cells to boron nitride nanoparticles: uptake mechanism and bio-mechanical characterization

    Energy Technology Data Exchange (ETDEWEB)

    Rasel, Md. Alim Iftekhar; Li, Tong; Nguyen, Trung Dung; Singh, Sanjleena [Queensland University of Technology (QUT), School of Chemistry, Physics and Mechanical Engineering (Australia); Zhou, Yinghong; Xiao, Yin [Queensland University of Technology (QUT), Institute of Health and Biomedical Innovation (Australia); Gu, YuanTong, E-mail: yuantong.gu@qut.edu.au [Queensland University of Technology (QUT), School of Chemistry, Physics and Mechanical Engineering (Australia)

    2015-11-15

    Boron nitride nanomaterials have attracted significant interest due to their superior chemical and physical properties. Despite these novel properties, investigation on the interaction between boron nitride nanoparticle (BN NP) and living systems has been limited. In this study, BN NP (100–250 nm) is assessed as a promising biomaterial for medical applications. The toxicity of BN NP is evaluated by assessing the cells behaviours both biologically (MTT assay, ROS detection etc.) and physically (atomic force microscopy). The uptake mechanism of BN NP is studied by analysing the alternations in cellular morphology based on cell imaging techniques. The results demonstrate in vitro cytocompatibility of BN NP with immense potential for use as an effective nanoparticle for various bio-medical applications.

  18. Biophysical response of living cells to boron nitride nanoparticles: uptake mechanism and bio-mechanical characterization

    International Nuclear Information System (INIS)

    Boron nitride nanomaterials have attracted significant interest due to their superior chemical and physical properties. Despite these novel properties, investigation on the interaction between boron nitride nanoparticle (BN NP) and living systems has been limited. In this study, BN NP (100–250 nm) is assessed as a promising biomaterial for medical applications. The toxicity of BN NP is evaluated by assessing the cells behaviours both biologically (MTT assay, ROS detection etc.) and physically (atomic force microscopy). The uptake mechanism of BN NP is studied by analysing the alternations in cellular morphology based on cell imaging techniques. The results demonstrate in vitro cytocompatibility of BN NP with immense potential for use as an effective nanoparticle for various bio-medical applications

  19. Eu/Tb codoped spindle-shaped fluorinated hydroxyapatite nanoparticles for dual-color cell imaging

    Science.gov (United States)

    Ma, Baojin; Zhang, Shan; Qiu, Jichuan; Li, Jianhua; Sang, Yuanhua; Xia, Haibing; Jiang, Huaidong; Claverie, Jerome; Liu, Hong

    2016-06-01

    Lanthanide doped fluorinated hydroxyapatite (FAp) nanoparticles are promising cell imaging nanomaterials but they are excited at wavelengths which do not match the light sources usually found in a commercial confocal laser scanning microscope (CLSM). In this work, we have successfully prepared spindle-shaped Eu/Tb codoped FAp nanoparticles by a hydrothermal method. Compared with single Eu doped FAp, Eu/Tb codoped FAp can be excited by a 488 nm laser, and exhibit both green and red light emission. By changing the amounts of Eu and Tb peaks, the emission in the green region (500-580 nm) can be decreased to the benefit of the emission in the red region (580-720 nm), thus reaching a balanced dual color emission. Using MC3T3-E1 cells co-cultured with Eu/Tb codoped FAp nanoparticles, it is observed that the nanoparticles are cytocompatible even at a concentration as high as 800 μg ml-1. The Eu/Tb codoped FAp nanoparticles are located in the cytoplasm and can be monitored by dual color--green and red imaging with a single excitation light at 488 nm. At a concentration of 200 μg ml-1, the cytoplasm is saturated in 8 hours, and Eu/Tb codoped FAp nanoparticles retain their fluorescence for at least 3 days. The cytocompatible Eu/Tb codoped FAp nanoparticles with unique dual color emission will be of great use for cell and tissue imaging.Lanthanide doped fluorinated hydroxyapatite (FAp) nanoparticles are promising cell imaging nanomaterials but they are excited at wavelengths which do not match the light sources usually found in a commercial confocal laser scanning microscope (CLSM). In this work, we have successfully prepared spindle-shaped Eu/Tb codoped FAp nanoparticles by a hydrothermal method. Compared with single Eu doped FAp, Eu/Tb codoped FAp can be excited by a 488 nm laser, and exhibit both green and red light emission. By changing the amounts of Eu and Tb peaks, the emission in the green region (500-580 nm) can be decreased to the benefit of the emission in the

  20. 医用可降解锌合金材料抗菌性能及细胞相容性的体外实验研究%Experimental study on the antibacterial property and cytocompatibility of medical biodegradable zinc alloy materials in vitro

    Institute of Scientific and Technical Information of China (English)

    张波; 周潘宇; 邱超; 姜里强; 王斐; 许硕贵

    2016-01-01

    细胞生长状况良好,CCK8检测提示不同时相点各浸提液组细胞RGR均大于75%,细胞毒性为0~1级,细胞毒性安全性合格。 MC3T3-E1细胞能黏附生长于锌合金与钛合金材料表面,细胞形态与钛合金组相比未见异常。结论锌合金材料具有良好的抗菌性能,对大肠杆菌及金黄色葡萄球菌均有抑菌效果;具有良好的细胞相容性,细胞毒性安全性合格,细胞能在其表面黏附生长。%Objective To study the antibacterial property and cytocompatibility of medical biodegradable zinc alloy in vitro. Methods Escherichia coli and Staphylococcus aureus strains were respectively mixed with LB culture medium, the concentration of 1. 0 × 108 CFU/mL was regulated by the bacterial turbidimetric instrument. The bacteria was cultured in carbon dioxide incubator of 37℃ for 24 h as bacteria original liquid. The same size of zinc alloy and titanium alloy ( Ti6Al4V) rods were prepared for experiment, the surface oxide layer was polished and removed, which was cleaned ultrasonically in 100%ethanol and distilled water, disinfected with ethylene oxide, standby. (1) Escherichia coli/Staphylococcus aureus strains were respectively co-cultured in LB culture medium with biodegradable zinc alloy, titanium alloy. The absorbance value at the time of 0、2、4、6、8、12、24、48、72 h after cultured at 600 nm wavelength was determined by enzyme-linked immunosorbent assay. (2) Zinc alloy and titanium alloy were respectively placed on Staphylococcus aureus strains solid culture plates, bacteriostatic circles were observed at 24、48 h after cultured. ( 3 ) L929 cells were cultured with different concentrations of zinc alloy extracts, cell morphology were observed at the time of 1、5 d after cultured, CCK8 method was used to detect the cell proliferation and cell relative rate of increment(RGR) was calculated. (4)The MC3T3-E1 cells were seeded respectively on zinc alloy surface and titanium alloy to observed adhesion and growth state 2

  1. Studies on screening of adsorbents for up-take of radioruthenium during vitrification of high-level radioactive waste

    International Nuclear Information System (INIS)

    106Ru (T1/2 = 369 days) and 103Ru (T1/2 = 39.3 days) are high specific activity fission products present in different types of nuclear waste generated during the reprocessing of spent nuclear fuel. A major part of it converts into RuO4 vapour during vitrification of high-level waste. Different types of materials like zeolite, perchloric acid treated siliceous brick, stainless steel, polythene, polypropylene, silicone were used as an adsorbent where RuO4 reduced to RuO2 and gets deposited on them which subsequently minimizes the spread of contamination. (author)

  2. Phenotypic nutrient up-take differences in an alley cropping system in semi-arid Machakos, Kenya

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Alley cropping of Cassia siamea and maize was studied insemi-arid Kenya for soil fertility improvement. Katumani composite maize was planted except in the short rains of 1988 (SR88) when a hybrid variety was sown. Therefore the grain yield per row increased differently in the alley cropped maize (CM). Sole maize (SM) and CM yields were higher in SR88 than in the long rains of 1988 (LR88) by 62% and 38%, while yields from the same treatments in LR89 were only 21% and 45% of those in SR88. These differences in relative maize yields are attributed to differences between the two maize varieties in competition under nutrient stress conditions.

  3. Effect of Arbuscular Mycorrhiza Fungi Inoculation on Growth and Up take of Mineral Nutrition in Ipomoea Aquatica.

    Directory of Open Access Journals (Sweden)

    Milton Halder

    2015-04-01

    Full Text Available A green house experiment was conducted to investigate the effect of arbuscular mycorrhiza inoculation on plant growth and uptake of mineral nutrition in Ipomoea aquatica considering the objective of using environmental friendly biofertilizer instead of chemical fertilizer. A common leafy vegetable plant Ipomoea aquatica was grown with mycorrhiza and without mycorrhiza for 42 days. After harvest the plants were analyzed for mineral nutrition concentration. Plant fresh weight, dry weight, macronutrient (P, K, Mg, Na, micronutrient (Fe, Mn, Zn concentration was higher in arbuscular mycorrhiza inoculated plant than non-mycorrhiza inoculated plant. For sustainable agriculture, introducing biofertilizer by using arbuscular mycorrhiza inoculation would be one of the most efficient techniques for replacing chemical fertilizer to meet the nutrient deficiency in nutrient deficient soils of Bangladesh.

  4. Effect of Arbuscular Mycorrhiza Fungi Inoculation on Growth and Up take of Mineral Nutrition in Ipomoea Aquatica.

    OpenAIRE

    Milton Halder; A. S. M Mujib; Muhammad Shahjalal Khan; Jagadish Chandra Joardar; Samina Akhter; P. P. Dhar

    2015-01-01

    A green house experiment was conducted to investigate the effect of arbuscular mycorrhiza inoculation on plant growth and uptake of mineral nutrition in Ipomoea aquatica considering the objective of using environmental friendly biofertilizer instead of chemical fertilizer. A common leafy vegetable plant Ipomoea aquatica was grown with mycorrhiza and without mycorrhiza for 42 days. After harvest the plants were analyzed for mineral nutrition concentration. Plant fresh weight, dry weight, macro...

  5. Cellular internalization of LiNbO3 nanocrystals for second harmonic imaging and the effects on stem cell differentiation

    Science.gov (United States)

    Li, Jianhua; Qiu, Jichuan; Guo, Weibo; Wang, Shu; Ma, Baojin; Mou, Xiaoning; Tanes, Michael; Jiang, Huaidong; Liu, Hong

    2016-03-01

    Second harmonic generation (SHG) nanocrystals have recently been reported to label cancer cells and other functional cell lines due to their unique double-frequency property. In this paper, we report for the first time the use of lithium niobate (LiNbO3, LN) nanocrystals as SHG labels for imaging stem cells. Rat mesenchymal stem cells (rMSCs) were labeled with LN nanocrystals in order to study the cellular internalization of the nanocrystals and the influence on stem cell differentiation. The results showed that LN nanocrystals were endocytosed by the rMSCs and the distribution of the internalized nanoparticles demonstrated a high consistency with the orientation of the actin filaments. Besides, LN-labeled rMSCs showed a concentration-dependent viability. Most importantly, rMSCs labeled with 50 μg per mL of LN nanocrystals retained their ability to differentiate into both osteogenic and adipogenic lineages. The results prove that LN nanocrystals can be used as a cytocompatible, near-infrared (NIR) light driven cell label for long-term imaging, without hindering stem cell differentiation. This work will promote the use of LN nanocrystals to broader applications like deep-tissue tracking, remote drug delivery and stem cell therapy.Second harmonic generation (SHG) nanocrystals have recently been reported to label cancer cells and other functional cell lines due to their unique double-frequency property. In this paper, we report for the first time the use of lithium niobate (LiNbO3, LN) nanocrystals as SHG labels for imaging stem cells. Rat mesenchymal stem cells (rMSCs) were labeled with LN nanocrystals in order to study the cellular internalization of the nanocrystals and the influence on stem cell differentiation. The results showed that LN nanocrystals were endocytosed by the rMSCs and the distribution of the internalized nanoparticles demonstrated a high consistency with the orientation of the actin filaments. Besides, LN-labeled rMSCs showed a concentration

  6. Spray deposition of live cells throughout the electrospinning process produces nanofibrous three-dimensional tissue scaffolds

    Directory of Open Access Journals (Sweden)

    Seil J

    2011-05-01

    Full Text Available Justin T Seil, Thomas J WebsterLaboratories for Nanomedicine Research, School of Engineering, Brown University, Providence, RI, USAAbstract: Compared with traditional in-vitro cell culture materials, three-dimensional nanofibrous scaffolds provide a superior environment for promoting cell functions. Since nanofibrous scaffolds have nanometer pore sizes, cells are unable to penetrate on their own, so must be incorporated into the scaffold during fabrication to ensure proper cell distribution. In this study, biodegradable and cytocompatible poly(DL-lactide-co-glycolide (PLGA nanofibers were produced using an electrospinning process. As a model cell line, fibroblasts were periodically sprayed from a pump-action spray bottle onto the developing scaffold. The viability of cells before and after spraying, and also after incorporation into the scaffold, was compared. Results indicated that cell spraying and the scaffold fabrication process did not significantly reduce cell viability. These findings, thus, contribute to the understanding of how to produce more physiological relevant cell-seeded nanofibrous scaffolds, an important element for the future of nanotechnology and tissue engineering.Keywords: nanomaterials, tissue engineering, PLGA, nanotechnology

  7. A novel Bruch's membrane-mimetic electrospun substrate scaffold for human retinal pigment epithelium cells.

    Science.gov (United States)

    Xiang, Ping; Wu, Kun-Chao; Zhu, Ying; Xiang, Lue; Li, Chong; Chen, Deng-Long; Chen, Feng; Xu, Guotong; Wang, Aijun; Li, Min; Jin, Zi-Bing

    2014-12-01

    Various artificial membranes have been used as scaffolds for retinal pigment epithelium cells (RPE) for monolayer reconstruction, however, long-term cell viability and functionality are still largely unknown. This study aimed to construct an ultrathin porous nanofibrous film to mimic Bruch's membrane, and in particular to investigate human RPE cell responses to the resultant substrates. An ultrathin porous nanofibrous membrane was fabricated by using regenerated wild Antheraea pernyi silk fibroin (RWSF), polycaprolactone (PCL) and gelatin (Gt) and displayed a thickness of 3-5 μm, with a high porosity and an average fiber diameter of 166 ± 85 nm. Human RPE cells seeded on the RWSF/PCL/Gt membranes showed a higher cell growth rate (p < 0.05), and a typical expression pattern of RPE signature genes, with reduced expression of inflammatory mediators. With long-term cultivation on the substrates, RPE cells exhibited characteristic polygonal morphology and development of apical microvilli. Immunocytochemisty demonstrated RPE-specific expression profiles in cells after 12-weeks of co-culture on RWSF/PCL/Gt membranes. Interestingly, the cells on the RWSF/PCL/Gt membranes functionally secreted polarized PEDF and phagocytosed labeled porcine POS. Furthermore, RWSF/PCL/Gt membranes transplanted subsclerally exhibited excellent biocompatibility without any evidence of inflammation or rejection. In conclusion, we established a novel RWSF-based substrate for growth of RPE cells with excellent cytocompatibility in vitro and biocompatibility in vivo for potential use as a prosthetic Bruch's membrane for RPE transplantation. PMID:25220295

  8. The effect of PVDF-TrFE scaffolds on stem cell derived cardiovascular cells.

    Science.gov (United States)

    Hitscherich, Pamela; Wu, Siliang; Gordan, Richard; Xie, Lai-Hua; Arinzeh, Treena; Lee, Eun Jung

    2016-07-01

    Recently, electrospun polyvinylidene fluoride (PVDF) and polyvinylidene fluoride-trifluoroethylene (PVDF-TrFE) scaffolds have been developed for tissue engineering applications. These materials have piezoelectric activity, wherein they can generate electric charge with minute mechanical deformations. Since the myocardium is an electroactive tissue, the unique feature of a piezoelectric scaffold is attractive for cardiovascular tissue engineering applications. In this study, we examined the cytocompatibility and function of pluripotent stem cell derived cardiovascular cells including mouse embryonic stem cell-derived cardiomyocytes (mES-CM) and endothelial cells (mES-EC) on PVDF-TrFE scaffolds. MES-CM and mES-EC adhered well to PVDF-TrFE and became highly aligned along the fibers. When cultured on scaffolds, mES-CM spontaneously contracted, exhibited well-registered sarcomeres and expressed classic cardiac specific markers such as myosin heavy chain, cardiac troponin T, and connexin43. Moreover, mES-CM cultured on PVDF-TrFE scaffolds responded to exogenous electrical pacing and exhibited intracellular calcium handling behavior similar to that of mES-CM cultured in 2D. Similar to cardiomyocytes, mES-EC also demonstrated high viability and maintained a mature phenotype through uptake of low-density lipoprotein and expression of classic endothelial cell markers including platelet endothelial cell adhesion molecule, endothelial nitric oxide synthase, and the arterial specific marker, Notch-1. This study demonstrates the feasibility of PVDF-TrFE scaffold as a candidate material for developing engineered cardiovascular tissues utilizing stem cell-derived cells. Biotechnol. Bioeng. 2016;113: 1577-1585. © 2015 Wiley Periodicals, Inc. PMID:26705272

  9. Injectable in situ forming xylitol-PEG-based hydrogels for cell encapsulation and delivery.

    Science.gov (United States)

    Selvam, Shivaram; Pithapuram, Madhav V; Victor, Sunita P; Muthu, Jayabalan

    2015-02-01

    Injectable in situ crosslinking hydrogels offer unique advantages over conventional prefabricated hydrogel methodologies. Herein, we synthesize poly(xylitol-co-maleate-co-PEG) (pXMP) macromers and evaluate their performance as injectable cell carriers for tissue engineering applications. The designed pXMP elastomers were non-toxic and water-soluble with viscosity values permissible for subcutaneous injectable systems. pXMP-based hydrogels prepared via free radical polymerization with acrylic acid as crosslinker possessed high crosslink density and exhibited a broad range of compressive moduli that could match the natural mechanical environment of various native tissues. The hydrogels displayed controlled degradability and exhibited gradual increase in matrix porosity upon degradation. The hydrophobic hydrogel surfaces preferentially adsorbed albumin and promoted cell adhesion and growth in vitro. Actin staining on cells cultured on thin hydrogel films revealed subconfluent cell monolayers composed of strong, adherent cells. Furthermore, fabricated 3D pXMP cell-hydrogel constructs promoted cell survival and proliferation in vitro. Cumulatively, our results demonstrate that injectable xylitol-PEG-based hydrogels possess excellent physical characteristics and exhibit exceptional cytocompatibility in vitro. Consequently, they show great promise as injectable hydrogel systems for in situ tissue repair and regeneration. PMID:25543981

  10. Cell-in-Shell Hybrids: Chemical Nanoencapsulation of Individual Cells.

    Science.gov (United States)

    Park, Ji Hun; Hong, Daewha; Lee, Juno; Choi, Insung S

    2016-05-17

    Nature has developed a fascinating strategy of cryptobiosis ("secret life") for counteracting the stressful, and often lethal, environmental conditions that fluctuate sporadically over time. For example, certain bacteria sporulate to transform from a metabolically active, vegetative state to an ametabolic endospore state. The bacterial endospores, encased within tough biomolecular shells, withstand the extremes of harmful stressors, such as radiation, desiccation, and malnutrition, for extended periods of time and return to a vegetative state by breaking their protective shells apart when their environment becomes hospitable for living. Certain ciliates and even higher organisms, for example, tardigrades, and others are also found to adopt a cryptobiotic strategy for survival. A common feature of cryptobiosis is the structural presence of tough sheaths on cellular structures. However, most cells and cellular assemblies are not "spore-forming" and are vulnerable to the outside threats. In particular, mammalian cells, enclosed with labile lipid bilayers, are highly susceptible to in vitro conditions in the laboratory and daily life settings, making manipulation and preservation difficult outside of specialized conditions. The instability of living cells has been a main bottleneck to the advanced development of cell-based applications, such as cell therapy and cell-based sensors. A judicious question arises: can cellular tolerance against harmful stresses be enhanced by simply forming cell-in-shell hybrid structures? Experimental results suggest that the answer is yes. A micrometer-sized "Iron Man" can be generated by chemically forming an ultrathin (<100 nm) but durable shell on a "non-spore-forming" cell. Since the report on silica nanoencapsulation of yeast cells, in which cytoprotective yeast-in-silica hybrids were formed, several synthetic strategies have been developed to encapsulate individual cells in a cytocompatible fashion, mimicking the cryptobiotic cell

  11. Mesenchymal stem cell interaction with ultra-smooth nanostructured diamond for wear-resistant orthopaedic implants.

    Science.gov (United States)

    Clem, William C; Chowdhury, Shafiul; Catledge, Shane A; Weimer, Jeffrey J; Shaikh, Faheem M; Hennessy, Kristin M; Konovalov, Valery V; Hill, Michael R; Waterfeld, Alfred; Bellis, Susan L; Vohra, Yogesh K

    2008-01-01

    Ultra-smooth nanostructured diamond (USND) can be applied to greatly increase the wear resistance of orthopaedic implants over conventional designs. Herein we describe surface modification techniques and cytocompatibility studies performed on this new material. We report that hydrogen (H)-terminated USND surfaces supported robust mesenchymal stem cell (MSC) adhesion and survival, while oxygen- (O) and fluorine (F)-terminated surfaces resisted cell adhesion, indicating that USND can be modified to either promote or prevent cell/biomaterial interactions. Given the favorable cell response to H-terminated USND, this material was further compared with two commonly used biocompatible metals, titanium alloy (Ti-6Al-4V) and cobalt chrome (CoCrMo). MSC adhesion and proliferation were significantly improved on USND compared with CoCrMo, although cell adhesion was greatest on Ti-6Al-4V. Comparable amounts of the pro-adhesive protein, fibronectin, were deposited from serum on the three substrates. Finally, MSCs were induced to undergo osteoblastic differentiation on the three materials, and deposition of a mineralized matrix was quantified. Similar amounts of mineral were deposited onto USND and CoCrMo, whereas mineral deposition was slightly higher on Ti-6Al-4V. When coupled with recently published wear studies, these in vitro results suggest that USND has the potential to reduce debris particle release from orthopaedic implants without compromising osseointegration. PMID:18490051

  12. Controlling mesenchymal stem cells differentiate into contractile smooth muscle cells on a TiO2 micro/nano interface: Towards benign pericytes environment for endothelialization.

    Science.gov (United States)

    Li, Jingan; Qin, Wei; Zhang, Kun; Wu, Feng; Yang, Ping; He, Zikun; Zhao, Ansha; Huang, Nan

    2016-09-01

    Building healthy and oriented smooth muscle cells (SMCs) environment is an effective method for improving the surface endothelialization of the cardiovascular implants. However, a long-term and stable source of SMCs for implantation without immune rejection and inflammation has not been solved, and mesenchymal stem cells (MSCs) differentiation may be a good choice. In this work, two types of TiO2 micro/nano interfaces were fabricated on titanium surface by photolithography and anodic oxidation. These TiO2 micro/nano interfaces were used to regulate the differentiation of the MSCs. The X-ray diffraction (XRD) detection showed that the TiO2 micro/nano interfaces possessed the anatase crystal structure, suggesting good cytocompatibility. The CCK-8 results indicated the TiO2 micro/nano interfaces improved MSC proliferation, further immunofluorescence staining and calculation of the cell morphology index proved the micro/nano surfaces also elongated MSCs and regulated MSCs oriented growth. The specific staining of α-SMA, CNN-1, vWF, CD44 and CD133 markers revealed that the micro/nano surfaces induced MSCs differentiation to contractile SMCs, and the endothelial cells (ECs) culture experiment indicated that the MSCs induced by micro/nano interfaces contributed to the ECs attachment and proliferation. This method will be further studied and applied for the surface modification of the cardiovascular implants. PMID:27232304

  13. Chitosan-collagen biomembrane embedded with calcium-aluminate enhances dentinogenic potential of pulp cells.

    Science.gov (United States)

    Soares, Diana Gabriela; Rosseto, Hebert Luís; Basso, Fernanda Gonçalves; Scheffel, Débora Salles; Hebling, Josimeri; Costa, Carlos Alberto de Souza

    2016-01-01

    The development of biomaterials capable of driving dental pulp stem cell differentiation into odontoblast-like cells able to secrete reparative dentin is the goal of current conservative dentistry. In the present investigation, a biomembrane (BM) composed of a chitosan/collagen matrix embedded with calcium-aluminate microparticles was tested. The BM was produced by mixing collagen gel with a chitosan solution (2:1), and then adding bioactive calcium-aluminate cement as the mineral phase. An inert material (polystyrene) was used as the negative control. Human dental pulp cells were seeded onto the surface of certain materials, and the cytocompatibility was evaluated by cell proliferation and cell morphology, assessed after 1, 7, 14 and 28 days in culture. The odontoblastic differentiation was evaluated by measuring alkaline phosphatase (ALP) activity, total protein production, gene expression of DMP-1/DSPP and mineralized nodule deposition. The pulp cells were able to attach onto the BM surface and spread, displaying a faster proliferative rate at initial periods than that of the control cells. The BM also acted on the cells to induce more intense ALP activity, protein production at 14 days, and higher gene expression of DSPP and DMP-1 at 28 days, leading to the deposition of about five times more mineralized matrix than the cells in the control group. Therefore, the experimental biomembrane induced the differentiation of pulp cells into odontoblast-like cells featuring a highly secretory phenotype. This innovative bioactive material can drive other protocols for dental pulp exposure treatment by inducing the regeneration of dentin tissue mediated by resident cells. PMID:27119587

  14. Biodegradable electrospun nanofibers coated with platelet-rich plasma for cell adhesion and proliferation

    Energy Technology Data Exchange (ETDEWEB)

    Diaz-Gomez, Luis [Departamento de Farmacia y Tecnología Farmacéutica, Facultad de Farmacia, Universidad de Santiago de Compostela, 15872 Santiago de Compostela (Spain); Instituto de Ortopedia y Banco de Tejidos Musculoesqueléticos, Universidad de Santiago de Compostela, 15872 Santiago de Compostela (Spain); Alvarez-Lorenzo, Carmen, E-mail: carmen.alvarez.lorenzo@usc.es [Departamento de Farmacia y Tecnología Farmacéutica, Facultad de Farmacia, Universidad de Santiago de Compostela, 15872 Santiago de Compostela (Spain); Concheiro, Angel [Departamento de Farmacia y Tecnología Farmacéutica, Facultad de Farmacia, Universidad de Santiago de Compostela, 15872 Santiago de Compostela (Spain); Silva, Maite [Instituto de Ortopedia y Banco de Tejidos Musculoesqueléticos, Universidad de Santiago de Compostela, 15872 Santiago de Compostela (Spain); Dominguez, Fernando [Fundación Publica Galega de Medicina Xenómica, Santiago de Compostela (Spain); Sheikh, Faheem A.; Cantu, Travis; Desai, Raj; Garcia, Vanessa L. [Department of Chemistry, University of Texas Pan American, Edinburg, TX 78541 (United States); Macossay, Javier, E-mail: jmacossay@utpa.edu [Department of Chemistry, University of Texas Pan American, Edinburg, TX 78541 (United States)

    2014-07-01

    Biodegradable electrospun poly(ε-caprolactone) (PCL) scaffolds were coated with platelet-rich plasma (PRP) to improve cell adhesion and proliferation. PRP was obtained from human buffy coat, and tested on human adipose-derived mesenchymal stem cells (MSCs) to confirm cell proliferation and cytocompatibility. Then, PRP was adsorbed on the PCL scaffolds via lyophilization, which resulted in a uniform sponge-like coating of 2.85 (S.D. 0.14) mg/mg. The scaffolds were evaluated regarding mechanical properties (Young's modulus, tensile stress and tensile strain), sustained release of total protein and growth factors (PDGF-BB, TGF-β1 and VEGF), and hemocompatibility. MSC seeded on the PRP–PCL nanofibers showed an increased adhesion and proliferation compared to pristine PCL fibers. Moreover, the adsorbed PRP enabled angiogenesis features observed as neovascularization in a chicken chorioallantoic membrane (CAM) model. Overall, these results suggest that PRP–PCL scaffolds hold promise for tissue regeneration applications. - Highlights: • Platelet-rich plasma (PRP) can be adsorbed on electrospun fibers via lyophilization. • PRP coating enhanced mesenchymal stem cell adhesion and proliferation on scaffolds. • PRP-coated scaffolds showed sustained release of growth factors. • Adsorbed PRP provided angiogenic features. • PRP-poly(ε-caprolactone) scaffolds hold promise for tissue regeneration applications.

  15. Biodegradable electrospun nanofibers coated with platelet-rich plasma for cell adhesion and proliferation

    International Nuclear Information System (INIS)

    Biodegradable electrospun poly(ε-caprolactone) (PCL) scaffolds were coated with platelet-rich plasma (PRP) to improve cell adhesion and proliferation. PRP was obtained from human buffy coat, and tested on human adipose-derived mesenchymal stem cells (MSCs) to confirm cell proliferation and cytocompatibility. Then, PRP was adsorbed on the PCL scaffolds via lyophilization, which resulted in a uniform sponge-like coating of 2.85 (S.D. 0.14) mg/mg. The scaffolds were evaluated regarding mechanical properties (Young's modulus, tensile stress and tensile strain), sustained release of total protein and growth factors (PDGF-BB, TGF-β1 and VEGF), and hemocompatibility. MSC seeded on the PRP–PCL nanofibers showed an increased adhesion and proliferation compared to pristine PCL fibers. Moreover, the adsorbed PRP enabled angiogenesis features observed as neovascularization in a chicken chorioallantoic membrane (CAM) model. Overall, these results suggest that PRP–PCL scaffolds hold promise for tissue regeneration applications. - Highlights: • Platelet-rich plasma (PRP) can be adsorbed on electrospun fibers via lyophilization. • PRP coating enhanced mesenchymal stem cell adhesion and proliferation on scaffolds. • PRP-coated scaffolds showed sustained release of growth factors. • Adsorbed PRP provided angiogenic features. • PRP-poly(ε-caprolactone) scaffolds hold promise for tissue regeneration applications

  16. Influence of the addition of β-TCP on the morphology, thermal properties and cell viability of poly (lactic acid) fibers obtained by electrospinning

    International Nuclear Information System (INIS)

    Electrospinning is a simple and low-cost way to fabricate fibers. Among the various polymers used in electrospinning process, the poly (lactic acid) (PLA) stands out due to its excellent biodegradability and biocompatibility. Calcium phosphate ceramics has been recognized as an attractive biomaterial because their chemical composition is similar to the mineral component of the hard tissue in the body. Furthermore, they are bioactive and osteoinductive and some are even quite biodegradable. The beta-tricalcium phosphate (β-TCP) particles were synthesized by solid state reaction. Different contents of β-TCP particles were incorporated in polymer matrices to form fibers of PLA/β-TCP composites by electrospinning aiming a possible application as a scaffold for tissue engineering. The fibers were characterized by scanning electron microscopy (SEM), infrared (FTIR), differential scanning calorimetry (DSC) and thermal gravimetric analysis (TGA). The average diameter of the fibers varied in the range of 260–519.6 ± 50 nm. The presence of β-TCP particles promoted changes on thermal properties of the fibers. The composite with 8 wt-% of β-TCP showed a low degree of crystallinity and can be used for application in tissue engineering. The cell viability was analyzed by reduction of the methyl tetrazolium salt by the pyruvate dehydrogenase enzymatic complex present in the matrix of mitochondria (MTT test). All PLA fiber groups, with different contents of β-TCP, showed cytocompatibility ability with non-cytotoxicity effect and bioactive properties using SBF assay. - Highlights: • PLA fibers with β-TCP particles incorporated were obtained by electrospinning aiming an application in tissue engineering.. • The average diameter of the fibers varied in the range of 260–519.6 ± 50 nm. • The composite with 8 wt.% of β-TCP showed a low degree of crystallinity and can be used for application in tissue engineering. • All PLA fibers groups, with different contents of

  17. Influence of the addition of β-TCP on the morphology, thermal properties and cell viability of poly (lactic acid) fibers obtained by electrospinning

    Energy Technology Data Exchange (ETDEWEB)

    Siqueira, L. [Laboratory of Bioceramics, Institute of Science and Technology, UNIFESP, São José dos Campos, SP (Brazil); Passador, F.R. [Laboratory of Polymer Processing, Institute of Science and Technology, UNIFESP, São José dos Campos, SP (Brazil); Costa, M.M. [Laboratory of Biomedical Nanotechnology, Development Research Institute IP& D, UNIVAP, São José dos Campos, SP (Brazil); Lobo, A.O., E-mail: aolobo@pq.cnpq.br [Laboratory of Biomedical Nanotechnology, Development Research Institute IP& D, UNIVAP, São José dos Campos, SP (Brazil); Sousa, E., E-mail: eliandra.sousa@unifesp.br [Laboratory of Bioceramics, Institute of Science and Technology, UNIFESP, São José dos Campos, SP (Brazil)

    2015-07-01

    Electrospinning is a simple and low-cost way to fabricate fibers. Among the various polymers used in electrospinning process, the poly (lactic acid) (PLA) stands out due to its excellent biodegradability and biocompatibility. Calcium phosphate ceramics has been recognized as an attractive biomaterial because their chemical composition is similar to the mineral component of the hard tissue in the body. Furthermore, they are bioactive and osteoinductive and some are even quite biodegradable. The beta-tricalcium phosphate (β-TCP) particles were synthesized by solid state reaction. Different contents of β-TCP particles were incorporated in polymer matrices to form fibers of PLA/β-TCP composites by electrospinning aiming a possible application as a scaffold for tissue engineering. The fibers were characterized by scanning electron microscopy (SEM), infrared (FTIR), differential scanning calorimetry (DSC) and thermal gravimetric analysis (TGA). The average diameter of the fibers varied in the range of 260–519.6 ± 50 nm. The presence of β-TCP particles promoted changes on thermal properties of the fibers. The composite with 8 wt-% of β-TCP showed a low degree of crystallinity and can be used for application in tissue engineering. The cell viability was analyzed by reduction of the methyl tetrazolium salt by the pyruvate dehydrogenase enzymatic complex present in the matrix of mitochondria (MTT test). All PLA fiber groups, with different contents of β-TCP, showed cytocompatibility ability with non-cytotoxicity effect and bioactive properties using SBF assay. - Highlights: • PLA fibers with β-TCP particles incorporated were obtained by electrospinning aiming an application in tissue engineering.. • The average diameter of the fibers varied in the range of 260–519.6 ± 50 nm. • The composite with 8 wt.% of β-TCP showed a low degree of crystallinity and can be used for application in tissue engineering. • All PLA fibers groups, with different contents of

  18. Effect of sterilization and water rinsing on cell adhesion to titanium surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Hirano, Mitsuhiro; Kozuka, Taro; Asano, Yuta; Kakuchi, Yuko [Instrument Analysis Center, Kitami Institute of Technology, 165 Koen-cho, Kitami, Hokkaido 090-8507 (Japan); Arai, Hirofumi [Department of Biotechnology and Environmental Chemistry, Kitami Institute of Technology, 165 Koen-cho, Kitami, Hokkaido 090-8507 (Japan); Ohtsu, Naofumi, E-mail: nohtsu@mail.kitami-it.ac.jp [Instrument Analysis Center, Kitami Institute of Technology, 165 Koen-cho, Kitami, Hokkaido 090-8507 (Japan)

    2014-08-30

    Highlights: • Sterilization and water rinsing affected the cell adhesion performance on Ti substrates. • The chemical state of the Ti surfaces was altered by sterilization and water rinsing. • There is a clear correlation between cell adhesiveness and the surface OH{sup −} concentration. - Abstract: In this study, the effects of sterilization and water rinsing on cell adhesion to titanium (Ti) surfaces were investigated. Ti substrates were treated using autoclave, dry-heating, and 70% ethanol. Thereafter, some of the substrates were rinsed with sterilized ultrapure water. Osteoblast-like MC3T3-E1 cells were seeded on the Ti surfaces and the numbers of adhered cells were counted after cultivation for 24 h. The number of cells adhered to ethanol-treated plates was lower than that on autoclave- and dry-heat-sterilized Ti substrates. However, interestingly, the cell adhesion performance on the ethanol-treated substrates was superior compared to that of the other substrates, after rinsing with ultrapure water. To investigate the origin of these differences, the chemical state of the treated surfaces was analyzed by X-ray photoelectron spectroscopy. We found a clear correlation between the number of adhered cells and the concentration of hydroxide groups (OH{sup −}) on the surface, thus indicating that a change in OH{sup −} concentration affects the cell adhesion performance on Ti substrates. Since the sterilization and subsequent water rinsing affect the cell adhesion on Ti substrates, we suggest that the sterilization methods should be unified to correctly evaluate the cytocompatibility of metallic materials.

  19. Cell-Instructive Graphene-Containing Nanocomposites Induce Multinucleated Myotube Formation.

    Science.gov (United States)

    Patel, Akhil; Xue, Yingfei; Mukundan, Shilpaa; Rohan, Lisa C; Sant, Vinayak; Stolz, Donna B; Sant, Shilpa

    2016-06-01

    Myoblast differentiation is a key step in myogenesis and has long been considered to be controlled mainly by biochemical cues such as growth factors. However, the tissue engineering approaches based on biochemical cues demonstrate low reproducibility as a precise spatial control over their bioactivity is challenging. Recently, substrate micro/nano-structure and electro-responsive properties are recognized for their important roles in myoblast differentiation. In this study, we hypothesized that engineering biophysical features such as nano/micro-fibrous structure and conductive properties into a single biomaterial scaffold will instruct the myoblasts to differentiate into multinucleated myotubes even in the absence of differentiation media. We fabricated nanocomposite scaffolds composed of conductive graphene nanosheets and polycaprolactone (PCL), a widely used biocompatible material. The resulting graphene-PCL scaffolds possess excellent conductivity due to graphene nanosheets and great processability, biodegradability and elastic mechanical properties conferred by PCL. Additionally, physicochemical and mechanical properties of nanocomposite scaffolds can be tuned by varying graphene concentration. Further, graphene-PCL nanocomposites and their 8-week degradation products exhibited remarkable cytocompatibility and promoted adhesion and proliferation of C2C12 mouse myoblast cells. Importantly, these nanocomposite scaffolds induced graphene concentration-dependent differentiation of C2C12 cells into multinucleated myotubes even in normal growth media suggesting their cell-instructive potential. Thus, graphene-PCL nanocomposite scaffolds can serve as a strategy to promote skeletal muscle regeneration without biochemical cues. PMID:26983841

  20. Modulation of Dental Pulp Stem Cell Odontogenesis in a Tunable PEG-Fibrinogen Hydrogel System

    Science.gov (United States)

    Lu, Qiqi; Pandya, Mirali; Rufaihah, Abdul Jalil; Rosa, Vinicius; Tong, Huei Jinn; Seliktar, Dror; Toh, Wei Seong

    2015-01-01

    Injectable hydrogels have the great potential for clinical translation of dental pulp regeneration. A recently developed PEG-fibrinogen (PF) hydrogel, which comprises a bioactive fibrinogen backbone conjugated to polyethylene glycol (PEG) side chains, can be cross-linked after injection by photopolymerization. The objective of this study was to investigate the use of this hydrogel, which allows tuning of its mechanical properties, as a scaffold for dental pulp tissue engineering. The cross-linking degree of PF hydrogels could be controlled by varying the amounts of PEG-diacrylate (PEG-DA) cross-linker. PF hydrogels are generally cytocompatible with the encapsulated dental pulp stem cells (DPSCs), yielding >85% cell viability in all hydrogels. It was found that the cell morphology of encapsulated DPSCs, odontogenic gene expression, and mineralization were strongly modulated by the hydrogel cross-linking degree and matrix stiffness. Notably, DPSCs cultured within the highest cross-linked hydrogel remained mostly rounded in aggregates and demonstrated the greatest enhancement in odontogenic gene expression. Consistently, the highest degree of mineralization was observed in the highest cross-linked hydrogel. Collectively, our results indicate that PF hydrogels can be used as a scaffold for DPSCs and offers the possibility of influencing DPSCs in ways that may be beneficial for applications in regenerative endodontics. PMID:26124841

  1. Modulation of Dental Pulp Stem Cell Odontogenesis in a Tunable PEG-Fibrinogen Hydrogel System.

    Science.gov (United States)

    Lu, Qiqi; Pandya, Mirali; Rufaihah, Abdul Jalil; Rosa, Vinicius; Tong, Huei Jinn; Seliktar, Dror; Toh, Wei Seong

    2015-01-01

    Injectable hydrogels have the great potential for clinical translation of dental pulp regeneration. A recently developed PEG-fibrinogen (PF) hydrogel, which comprises a bioactive fibrinogen backbone conjugated to polyethylene glycol (PEG) side chains, can be cross-linked after injection by photopolymerization. The objective of this study was to investigate the use of this hydrogel, which allows tuning of its mechanical properties, as a scaffold for dental pulp tissue engineering. The cross-linking degree of PF hydrogels could be controlled by varying the amounts of PEG-diacrylate (PEG-DA) cross-linker. PF hydrogels are generally cytocompatible with the encapsulated dental pulp stem cells (DPSCs), yielding >85% cell viability in all hydrogels. It was found that the cell morphology of encapsulated DPSCs, odontogenic gene expression, and mineralization were strongly modulated by the hydrogel cross-linking degree and matrix stiffness. Notably, DPSCs cultured within the highest cross-linked hydrogel remained mostly rounded in aggregates and demonstrated the greatest enhancement in odontogenic gene expression. Consistently, the highest degree of mineralization was observed in the highest cross-linked hydrogel. Collectively, our results indicate that PF hydrogels can be used as a scaffold for DPSCs and offers the possibility of influencing DPSCs in ways that may be beneficial for applications in regenerative endodontics. PMID:26124841

  2. Modulation of Dental Pulp Stem Cell Odontogenesis in a Tunable PEG-Fibrinogen Hydrogel System

    Directory of Open Access Journals (Sweden)

    Qiqi Lu

    2015-01-01

    Full Text Available Injectable hydrogels have the great potential for clinical translation of dental pulp regeneration. A recently developed PEG-fibrinogen (PF hydrogel, which comprises a bioactive fibrinogen backbone conjugated to polyethylene glycol (PEG side chains, can be cross-linked after injection by photopolymerization. The objective of this study was to investigate the use of this hydrogel, which allows tuning of its mechanical properties, as a scaffold for dental pulp tissue engineering. The cross-linking degree of PF hydrogels could be controlled by varying the amounts of PEG-diacrylate (PEG-DA cross-linker. PF hydrogels are generally cytocompatible with the encapsulated dental pulp stem cells (DPSCs, yielding >85% cell viability in all hydrogels. It was found that the cell morphology of encapsulated DPSCs, odontogenic gene expression, and mineralization were strongly modulated by the hydrogel cross-linking degree and matrix stiffness. Notably, DPSCs cultured within the highest cross-linked hydrogel remained mostly rounded in aggregates and demonstrated the greatest enhancement in odontogenic gene expression. Consistently, the highest degree of mineralization was observed in the highest cross-linked hydrogel. Collectively, our results indicate that PF hydrogels can be used as a scaffold for DPSCs and offers the possibility of influencing DPSCs in ways that may be beneficial for applications in regenerative endodontics.

  3. [Comparison of fibroblastic cell compatibility of type I collagen-immobilized titanium between electrodeposition and immersion].

    Science.gov (United States)

    Kyuragi, Takeru

    2014-03-01

    Titanium is widely used for medical implants. While many techniques for surface modification have been studied for optimizing its biocompatibility with hard tissues, little work has been undertaken to explore ways of maximizing its biocompatibility with soft tissues. We investigated cell attachment to titanium surfaces modified with bovine Type I collagen immobilized by either electrodeposition or a conventional immersion technique. The apparent thickness and durability of the immobilized collagen layer were evaluated prior to incubation of the collagen-immobilized titanium surfaces with NIH/3T3 mouse embryonic fibroblasts. The initial cell attachment and expression of actin and vinculin were evaluated. We determined that the immobilized collagen layer was much thicker and more durable when placed using the electrodeposition technique than the immersion technique. Both protocols produced materials that promoted better cell attachment, growth and structural protein expression than titanium alone. However, electrodeposition was ultimately superior to immersion because it is quicker to perform and produces a more durable collagen coating. We conclude that electrodeposition is an effective technique for immobilizing type I collagen on titanium surfaces, thus improving their cytocompatibility with fibroblasts. PMID:24812763

  4. Visible light photoinitiation of mesenchymal stem cell-laden bioresponsive hydrogels

    Directory of Open Access Journals (Sweden)

    CS Bahney

    2011-07-01

    Full Text Available Biological activity can be added to synthetic scaffolds by incorporating functional peptide sequences that provide enzyme-mediated degradation sites, facilitate cellular adhesion or stimulate signaling pathways. Poly(ethylene glycol diacrylate is a popular synthetic base for tissue engineering scaffolds because it creates a hydrophilic environment that can be chemically manipulated to add this biological functionality. Furthermore, the acrylate groups allow for encapsulation of cells using photopolymerization under physiological conditions. One complication with the addition of these peptides is that aromatic amino acids absorb light at 285nm and compete with the ultraviolet (UV-sensitive photoinitiators such as IrgacureTM 2959 (I2959, the most commonly used initiator for cytocompatible photoencapsulation of cells into synthetic scaffolds. In this study we define non-toxic conditions for photoencapsulation of human mesenchymal stem cells (hMSC in PEGDA scaffolds using a visible light photoinitiator system composed of eosin Y, triethanolamine and 1-vinyl-2-pyrrolidinone. This visible light photoinitiator produced hydrogel scaffolds with an increased viability of encapsulated hMSCs and a more tightly crosslinked network in one-third the time of UV polymerization with I2959.

  5. Cytocompatible antifungal acrylic resin containing silver nanoparticles for dentures

    OpenAIRE

    Acosta-Torres LS; Mendieta I; Nuñez-Anita RE; Cajero-Juárez M; Castaño VM

    2012-01-01

    Laura Susana Acosta-Torres,1 Irasema Mendieta,2 Rosa Elvira Nuñez-Anita,3 Marcos Cajero-Juárez,3 Víctor M Castaño41National School of Higher Education, School of Dentistry - Leon Unit, National Autonomus University of Mexico (UNAM), Leon, Guanajuato, 2Neurobiology Institute, National Autonomus University of Mexico (UNAM), Juriquilla, Queretaro, 3Animal Biotechnology Laboratory, Faculty of Veterinary Medicine at San Nicolas de Hidalgo, Michoac&aa...

  6. Novel strontium-doped bioactive glass nanoparticles enhance proliferation and osteogenic differentiation of human bone marrow stromal cells

    International Nuclear Information System (INIS)

    The present study investigates a new family of bioactive glass nanoparticles with and without Sr-doping focusing on the influence of the nanoparticles on human bone marrow stromal cells (hBMSCs) in vitro. The bioactive glass nanoparticles were fabricated by flame spray synthesis and a particle diameter of 30–35 nm was achieved. Glass nanoparticles were undoped (BG 13-93-0Sr) or doped with 5 wt% strontium (Sr) (BG 13-93-5Sr) and used at concentrations of 10 and 100 μg/cm² (particles per culture plate area), respectively. Cells were cultured for 14 days after which the samples were analysed regarding metabolic activity and expression of various bone-specific genes. Cell growth and morphology indicated the high cytocompatibility of the nanoparticulate bioactive glass. The presence of the nanoparticles enhanced cell growth compared to the plain polystyrene control group. At a concentration of 100 μg/cm², Sr-doped particles led to significantly enhanced gene expression of osteocalcin, collagen type 1 and vascular endothelial growth factor. Thus, Sr-doped nanoparticles showing a dose-dependent increase of osteogenic differentiation in hBMSCs are a promising biomaterial for bone regeneration purposes

  7. Novel strontium-doped bioactive glass nanoparticles enhance proliferation and osteogenic differentiation of human bone marrow stromal cells

    Energy Technology Data Exchange (ETDEWEB)

    Strobel, L. A. [University of Erlangen-Nuremberg Medical Center, Department of Plastic and Hand Surgery (Germany); Hild, N.; Mohn, D.; Stark, W. J. [ETH Zurich, Department of Chemistry and Applied Biosciences, Institute for Chemical and Bioengineering (Switzerland); Hoppe, A. [University of Erlangen-Nuremberg, Department of Materials Science and Engineering, Institute of Biomaterials (Germany); Gbureck, U. [University of Wuerzburg, Department for Functional Materials in Medicine and Dentistry (Germany); Horch, R. E.; Kneser, U. [University of Erlangen-Nuremberg Medical Center, Department of Plastic and Hand Surgery (Germany); Boccaccini, A. R., E-mail: aldo.boccaccini@ww.uni-erlangen.de [University of Erlangen-Nuremberg, Department of Materials Science and Engineering, Institute of Biomaterials (Germany)

    2013-07-15

    The present study investigates a new family of bioactive glass nanoparticles with and without Sr-doping focusing on the influence of the nanoparticles on human bone marrow stromal cells (hBMSCs) in vitro. The bioactive glass nanoparticles were fabricated by flame spray synthesis and a particle diameter of 30-35 nm was achieved. Glass nanoparticles were undoped (BG 13-93-0Sr) or doped with 5 wt% strontium (Sr) (BG 13-93-5Sr) and used at concentrations of 10 and 100 {mu}g/cm Superscript-Two (particles per culture plate area), respectively. Cells were cultured for 14 days after which the samples were analysed regarding metabolic activity and expression of various bone-specific genes. Cell growth and morphology indicated the high cytocompatibility of the nanoparticulate bioactive glass. The presence of the nanoparticles enhanced cell growth compared to the plain polystyrene control group. At a concentration of 100 {mu}g/cm Superscript-Two , Sr-doped particles led to significantly enhanced gene expression of osteocalcin, collagen type 1 and vascular endothelial growth factor. Thus, Sr-doped nanoparticles showing a dose-dependent increase of osteogenic differentiation in hBMSCs are a promising biomaterial for bone regeneration purposes.

  8. Poly(urethane-dimethylsiloxane) copolymers displaying a range of soft segment contents, noncytotoxic chemistry, and nonadherent properties toward endothelial cells.

    Science.gov (United States)

    Stefanović, Ivan S; Djonlagić, Jasna; Tovilović, Gordana; Nestorov, Jelena; Antić, Vesna V; Ostojić, Sanja; Pergal, Marija V

    2015-04-01

    Polyurethane copolymers based on α,ω-dihydroxypropyl poly(dimethylsiloxane) (PDMS) with a range of soft segment contents were prepared by two-stage polymerization, and their microstructures, thermal, thermomechanical, and surface properties, as well as in vitro hemo- and cytocompatibility were evaluated. All utilized characterization methods confirmed the existence of moderately microphase separated structures with the appearance of some microphase mixing between segments as the PDMS (i.e., soft segment) content increased. Copolymers showed higher crystallinity, storage moduli, surface roughness, and surface free energy, but less hydrophobicity with decreasing PDMS content. Biocompatibility of copolymers was evaluated using an endothelial EA.hy926 cell line by direct contact, an extraction method and after pretreatment of copolymers with multicomponent protein mixture, as well as by a competitive protein adsorption assay. Copolymers showed no toxic effect to endothelial cells and all copolymers, except that with the lowest PDMS content, exhibited resistance to endothelial cell adhesion, suggesting their unsuitability for long-term biomedical devices which particularly require re-endothelialization. All copolymers exhibited excellent resistance to fibrinogen adsorption and adsorbed more albumin than fibrinogen in the competitive adsorption assay, suggesting their good hemocompatibility. The noncytotoxic chemistry of these synthesized materials, combined with their nonadherent properties which are inhospitable to cell attachment and growth, underlie the need for further investigations to clarify their potential for use in short-term biomedical devices. PMID:25046378

  9. Surface modification of PVDF using non-mammalian sources of collagen for enhancement of endothelial cell functionality.

    Science.gov (United States)

    Wang, Jun Kit; Xiong, Gordon Minru; Luo, Baiwen; Choo, Chee Chong; Yuan, Shaojun; Tan, Nguan Soon; Choong, Cleo

    2016-03-01

    Although polyvinylidene fluoride (PVDF) is non-toxic and stable in vivo, its hydrophobic surface has limited its bio-applications due to poor cell-material interaction and thrombus formation when used in blood contacting devices. In this study, surface modification of PVDF using naturally derived non-mammalian collagen was accomplished via direct surface-initiated atom transfer radical polymerisation (SI-ATRP) to enhance its cytocompatibility and hemocompatibility. Results showed that Type I collagen was successfully extracted from fish scales and bullfrog skin. The covalent immobilisation of fish scale-derived collagen (FSCOL) and bullfrog skin-derived collagen (BFCOL) onto the PVDF surface improves the attachment and proliferation of human umbilical vein endothelial cells (HUVECs). Furthermore, both FSCOL and BFCOL had comparable anti-thrombogenic profiles to that of commercially available bovine collagen (BVCOL). Also, cell surface expression of the leukocyte adhesion molecule was lower on HUVECs cultured on non-mammalian collagen surfaces than on BVCOL, which is an indication of lower pro-inflammatory response. Overall, results from this study demonstrated that non-mammalian sources of collagen could be used to confer bioactivity to PVDF, with comparable cell-material interactions and hemocompatibility to BVCOL. Additionally, higher expression levels of Type IV collagen in HUVECs cultured on FSCOL and BFCOL were observed as compared to BVCOL, which is an indication that the non-mammalian sources of collagen led to a better pro-angiogenic properties, thus making them suitable for blood contacting applications. PMID:26758892

  10. Effect of lecithin content blend with poly (L-lactic acid) on viability and proliferation of mesenchymal stem cells

    International Nuclear Information System (INIS)

    Lecithin constitutes a natural mixture of phospholipids and neutral lipids and plays critical roles in cellular membrane structure and cellular signaling. In this study, lecithin was blended with poly (L-lactic acid) (PLLA) for modifying the surface of PLLA because it might obtain appropriate hydrophilicity and biocompatibility. The modified PLLA films were manufactured using conventional solvent-casting technique. The hydrophilicity clearly increased with an increase of lecithin content in the polymer blends, as determined by measuring the water contact angle (WCA). The cytocompatibility and any potential cytotoxic effects were studied over 7 days by seeding mesenchymal stem cells (MSCs) on the films of PLLA containing 0-15% lecithin (wt.%), in comparison with tissue culture plates (TCPs). Cell viability and proliferation were assessed using WST-8, lactate dehydrogenase (LDH) and cell morphology was studied by toluidine blue and propidium iodide staining. This results obtained above suggested that 5%lecithin-containing PLLA films could possess the optimal hydrophilicity, higher adhesion and proliferation of MSCs for a prolonged period and did not demonstrate any significant toxic effects to cells. The study showed that the hydrophilicity and biocompatibility of the modified PLLA were markedly improved by directly introducing lecithin into the polymer without the use of multiple synthetic steps. The information obtained should be useful for future research in vascular tissue engineering (VTE).

  11. Enhanced endothelial cell functions on rosette nanotube-coated titanium vascular stents

    Directory of Open Access Journals (Sweden)

    Eli Fine

    2009-04-01

    Full Text Available Eli Fine1, Lijie Zhang1, Hicham Fenniri2, Thomas J Webster1 1Department of Engineering, Brown University, Providence, RI, USA; 2National Institute for Nanotechnology and Department of Chemistry, University of Alberta, Edmonton, AB, CanadaAbstract: One of the main problems with current vascular stents is a lack of endothelial cell interactions, which if sufficient, would create a uniform healthy endothelium masking the underlying foreign metal from inflammatory cell interference. Moreover, if endothelial cells from the arterial wall do not adhere to the stent, the stent can become loose and dislodge. Therefore, the objective of this in vitro study was to design a novel biomimetic nanostructured coating (that does not contain drugs on conventional vascular stent materials (specifically, titanium for improving vascular stent applications. Rosette nanotubes (RNTs are a new class of biomimetic nanotubes that self-assemble from DNA base analogs and have been shown in previous studies to sufficiently coat titanium and enhance osteoblast cell functions. RNTs have many desirable properties for use as vascular stent coatings including spontaneous self-assembly in body fluids, tailorable surface chemistry for specific implant applications, and nanoscale dimensions similar to those of the natural vascular extracellular matrix. Importantly, the results of this study provided the first evidence that RNTs functionalized with lysine (RNT–K, even at low concentrations, significantly increase endothelial cell density over uncoated titanium. Specifically, 0.01 mg/mL RNT–K coated titanium increased endothelial cell density by 37% and 52% compared to uncoated titanium after 4 h and three days, respectively. The excellent cytocompatibility properties of RNTs (as demonstrated here for the first time for endothelial cells suggest the need for the further exploration of these novel nanostructured materials for vascular stent applications.Keywords: stents

  12. Polyampholyte- and nanosilicate-based soft bionanocomposites with tailorable mechanical and cell adhesion properties.

    Science.gov (United States)

    Jain, Minkle; Matsumura, Kazuaki

    2016-06-01

    Engineered tissues are excellent substitutes for treating organ failure associated with disease, injury, and degeneration. Designing new biomaterials with controlled release profiles, good mechanical properties, and cell adhesion characteristics can be useful for the formation of specific functional tissues. Here, we report the formulation of nanocomposite hydrogels based on carboxylated poly-l-lysine and synthetic clay laponite XLG in which four-arm polyethylene glycol with N-hydroxy succinimide ester (PEG-NHS) was used as the chemical crosslinker. Interestingly, the degradation of this gel could be adjusted from a few days to a few months. Incorporation of laponite XLG resulted in the formation of mechanically tough hydrogels and conferred cytocompatibility. The mechanical properties of the nanocomposite could be modulated by changing the crosslinking density and laponite concentration. The feasibility of using this system for cellular therapies was investigated by evaluating cell adhesion on the nanocomposite surface. Thus, these nanocomposites can serve as scaffolds with tunable mechanical and degradation properties that also provide structural integrity to tissue constructs. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 104A: 1379-1386, 2016. PMID:26833827

  13. Platelet Lysate-Modified Porous Silicon Microparticles for Enhanced Cell Proliferation in Wound Healing Applications.

    Science.gov (United States)

    Fontana, Flavia; Mori, Michela; Riva, Federica; Mäkilä, Ermei; Liu, Dongfei; Salonen, Jarno; Nicoletti, Giovanni; Hirvonen, Jouni; Caramella, Carla; Santos, Hélder A

    2016-01-13

    The new frontier in the treatment of chronic nonhealing wounds is the use of micro- and nanoparticles to deliver drugs or growth factors into the wound. Here, we used platelet lysate (PL), a hemoderivative of platelets, consisting of a multifactorial cocktail of growth factors, to modify porous silicon (PSi) microparticles and assessed both in vitro and ex vivo the properties of the developed microsystem. PL-modified PSi was assessed for its potential to induce proliferation of fibroblasts. The wound closure-promoting properties of the microsystem were then assessed in an in vitro wound healing assay. Finally, the PL-modified PSi microparticles were evaluated in an ex vivo experiment over human skin. It was shown that PL-modified PSi microparticles were cytocompatible and enhanced the cell proliferation in different experimental settings. In addition, this microsystem promoted the closure of the gap between the fibroblast cells in the wound healing assay, in periods of time comparable with the positive control, and induced a proliferation and regeneration process onto the human skin in an ex vivo experiment. Overall, our results show that PL-modified PSi microparticles are suitable microsystems for further development toward applications in the treatment of chronic nonhealing wounds. PMID:26652045

  14. In situ supramolecular hydrogel based on hyaluronic acid and dextran derivatives as cell scaffold.

    Science.gov (United States)

    Chen, Jing-Xiao; Cao, Lu-Juan; Shi, Yu; Wang, Ping; Chen, Jing-Hua

    2016-09-01

    In this study, hyaluronic acid-β-cyclodextrin conjugate (HA-CD) and dextran-2-naphthylacetic acid conjugate (Dex-NAA) were synthesized as two gelators. The degrees of substitution (DS) of these two gelators were determined to be 15.5 and 7.4%, respectively. Taking advantages of the strong and selective host-guest interaction between β-CD and 2-NAA, the mixture of two gelators could form supramolecular hydrogel in situ. Moreover, the pore size, gelation time, swelling ratio as well as modulus of the hydrogel could be adjusted by simply varying the contents of HA-CD and Dex-NAA. NIH/3T3 cells that entrapped in hydrogel grew well as compared with that cultured in plates, indicating a favorable cytocompatibility of the hydrogel. Collectively, the results demonstrated that the HA-Dex hydrogel could potentially be applied in tissue engineering as cell scaffold. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 104A: 2263-2270, 2016. PMID:27087451

  15. Poly(ε-caprolactone) modified with fusion protein containing self-assembled hydrophobin and functional peptide for selective capture of human blood outgrowth endothelial cells.

    Science.gov (United States)

    Huang, Yujian; Zhang, Suai; Niu, Baolong; Wang, Dandan; Wang, Zefang; Feng, Shuren; Xu, Haijin; Kong, Deling; Qiao, Mingqiang

    2013-01-01

    Human blood outgrowth endothelial cells (HBOECs)-specific binding peptide, TPSLEQRTVYAK (TPS), was proposed to be applied on autologous cell therapy for treating cardiovascular diseases. Hydrophobins, as a family of self-assembly proteins originated from fungi, have demonstrated unique characteristics to modulate surface properties of other materials coated with these amphiphilic proteins in previous studies. In this report, a fusion protein which was composed of class I hydrophobin HGFI originated from Grifola frondosa and functional peptide TPS was expressed by Pichia pastoris expression system. Then, we purified this fusion protein by ultrafiltration and reverse-phase high performance liquid chromatography. Water contact angle, X-ray photoelectron spectroscopy measurements indicated that the surface properties of hydrophobin were greatly preserved by this fusion protein while comparing with wild HGFI. Cell binding assay showed that this fusion protein demonstrated specific binding property to HBOECs while coating on biodegradable poly(ε-caprolactone) (PCL) grafts in the presence of fetal bovine serum, whereas HGFI-coated PCL non-selectively enhanced all types of cells attachments. Methylthiazol tetrazolium assay was employed to verify the cytocompatibility of this fusion protein-based material. This work presented a new perspective to apply hydrophobin in tissue engineering and regenerative medicine and provided an alternative approach to study endothelial progenitor cells. PMID:23010042

  16. Enhanced adherence of mouse fibroblast and vascular cells to plasma modified polyethylene

    Energy Technology Data Exchange (ETDEWEB)

    Reznickova, Alena, E-mail: alena.reznickova@vscht.cz [Department of Solid State Engineering, Institute of Chemical Technology Prague, 166 28 Prague 6 (Czech Republic); Novotna, Zdenka, E-mail: zdenka1.novotna@vscht.cz [Department of Solid State Engineering, Institute of Chemical Technology Prague, 166 28 Prague 6 (Czech Republic); Kolska, Zdenka [Faculty of Science, J.E. Purkyně University, 400 96 Usti nad Labem (Czech Republic); Kasalkova, Nikola Slepickova [Department of Solid State Engineering, Institute of Chemical Technology Prague, 166 28 Prague 6 (Czech Republic); Rimpelova, Silvie [Department of Biochemistry and Microbiology, Institute of Chemical Technology Prague, 166 28 Prague 6 (Czech Republic); Svorcik, Vaclav [Department of Solid State Engineering, Institute of Chemical Technology Prague, 166 28 Prague 6 (Czech Republic)

    2015-07-01

    Since the last decade, tissue engineering has shown a sensational promise in providing more viable alternatives to surgical procedures for harvested tissues, implants and prostheses. Biomedical polymers, such as low-density polyethylene (LDPE), high-density polyethylene (HDPE) and ultra-high molecular weight polyethylene (UHMWPE), were activated by Ar plasma discharge. Degradation of polymer chains was examined by determination of the thickness of ablated layer. The amount of an ablated polymer layer was measured by gravimetry. Contact angle, measured by goniometry, was studied as a function of plasma exposure and post-exposure aging times. Chemical structure of modified polymers was characterized by angle resolved X-ray photoelectron spectroscopy. Surface chemistry and polarity of the samples were investigated by electrokinetic analysis. Changes in surface morphology were followed using atomic force microscopy. Cytocompatibility of plasma activated polyethylene foils was studied using two distinct model cell lines; VSMCs (vascular smooth muscle cells) as a model for vascular graft testing and connective tissue cells L929 (mouse fibroblasts) approved for standardized material cytotoxicity testing. Specifically, the cell number, morphology, and metabolic activity of the adhered and proliferated cells on the polyethylene matrices were studied in vitro. It was found that the plasma treatment caused ablation of the polymers, resulting in dramatic changes in their surface morphology and roughness. ARXPS and electrokinetic measurements revealed oxidation of the polymer surface. It was found that plasma activation has a positive effect on the adhesion and proliferation of VSMCs and L929 cells. - Highlights: • Plasma activation of LDPE, HDPE and UHMWPE • Study of surface properties by several techniques: ARXPS, AFM, zeta-potential, and goniometry • Investigation of adhesion and spreading of vascular smooth muscle cells (VSMCs) and mouse fibroblasts (L929)

  17. Enhanced adherence of mouse fibroblast and vascular cells to plasma modified polyethylene

    International Nuclear Information System (INIS)

    Since the last decade, tissue engineering has shown a sensational promise in providing more viable alternatives to surgical procedures for harvested tissues, implants and prostheses. Biomedical polymers, such as low-density polyethylene (LDPE), high-density polyethylene (HDPE) and ultra-high molecular weight polyethylene (UHMWPE), were activated by Ar plasma discharge. Degradation of polymer chains was examined by determination of the thickness of ablated layer. The amount of an ablated polymer layer was measured by gravimetry. Contact angle, measured by goniometry, was studied as a function of plasma exposure and post-exposure aging times. Chemical structure of modified polymers was characterized by angle resolved X-ray photoelectron spectroscopy. Surface chemistry and polarity of the samples were investigated by electrokinetic analysis. Changes in surface morphology were followed using atomic force microscopy. Cytocompatibility of plasma activated polyethylene foils was studied using two distinct model cell lines; VSMCs (vascular smooth muscle cells) as a model for vascular graft testing and connective tissue cells L929 (mouse fibroblasts) approved for standardized material cytotoxicity testing. Specifically, the cell number, morphology, and metabolic activity of the adhered and proliferated cells on the polyethylene matrices were studied in vitro. It was found that the plasma treatment caused ablation of the polymers, resulting in dramatic changes in their surface morphology and roughness. ARXPS and electrokinetic measurements revealed oxidation of the polymer surface. It was found that plasma activation has a positive effect on the adhesion and proliferation of VSMCs and L929 cells. - Highlights: • Plasma activation of LDPE, HDPE and UHMWPE • Study of surface properties by several techniques: ARXPS, AFM, zeta-potential, and goniometry • Investigation of adhesion and spreading of vascular smooth muscle cells (VSMCs) and mouse fibroblasts (L929)

  18. LBL coating of type I collagen and hyaluronic acid on aminolyzed PLLA to enhance the cell-material interaction

    Directory of Open Access Journals (Sweden)

    M. Y. Zhao

    2014-05-01

    Full Text Available The aim of the present work is to assemble extracellular matrix components onto poly (L-lactic acid (PLLA films using layer-by-layer (LBL depositing method to enhance the cell-material interaction. To introduce charges onto the hydrophobic and neutral PLLA surface so that the electronic assembly can be processed, poly (ethylene imine (PEI was covalently bonded to modify the PLLA films. Positively charged collagen I (Col I was then deposited onto the aminolyzed PLLA film surface in a LBL assembly manner using hyaluronic acid (HA as a negatively charged polyelectrolyte. The PEI modification efficiency was monitored via X-ray photoelectron spectroscopy (XPS measurements. The results of Surface Plasmon Resonance (SPR and Water contact angle (WCA monitoring the LBL assemble process presented that the HA/Col I deposited alternately onto the PLLA surface. The surface topography of the films was observed by Atomic force microscope (AFM. In vitro osteoblast culture found that the presence of Col I layer greatly improved the cytocompatibility of the PLLA films in terms of cell viability, cell proliferation and Alkaline Phosphatase (ALP expression. Furthermore, osteoblast extensions were found to be directed by contact guidance of the aligned Col I fibrils. Thus, these very flexible systems may allow broad applications for improve the bioactivity of polymeric materials, which might be a potential application for bone tissue engineering.

  19. Rapid biomimetic mineralization of collagen fibrils and combining with human umbilical cord mesenchymal stem cells for bone defects healing.

    Science.gov (United States)

    Ye, Bihua; Luo, Xueshi; Li, Zhiwen; Zhuang, Caiping; Li, Lihua; Lu, Lu; Ding, Shan; Tian, Jinhuan; Zhou, Changren

    2016-11-01

    Collagen biomineralization is regulated by complicated interactions between the collagen matrix and non-collagenous extracellular proteins. Here, the use of sodium tripolyphosphate to simulate the templating functional motif of the C-terminal fragment of non-collagenous proteins is reported, and a low molecular weight polyacrylic acid served as a sequestration agent to stabilize amorphous calcium phosphate into nanoprecursors. Self-assembled collagen fibrils served as a fixed template for achieving rapid biomimetic mineralization in vitro. Results demonstrated that, during the mineralization process, intrafibrillar and extrafibrillar hydroxyapatite mineral with collagen fibrils formed and did so via bottom-up nanoparticle assembly based on the non-classical crystallization approach in the presence of these dual biomimetic functional analogues. In vitro human umbilical cord mesenchymal stem cell (hUCMSC) culture found that the mineralized scaffolds have a better cytocompatibility in terms of cell viability, adhesion, proliferation, and differentiation into osteoblasts. A rabbit femoral condyle defect model was established to confirm the ability of the n-HA/collagen scaffolds to facilitate bone regeneration and repair. The images of gross anatomy, MRI, CT and histomorphology taken 6 and 12weeks after surgery showed that the biomimetic mineralized collagen scaffolds with hUCMSCs can promote the healing speed of bone defects in vivo, and both of the scaffolds groups performing better than the bone defect control group. As new bone tissue formed, the scaffolds degraded and were gradually absorbed. All these results demonstrated that both of the scaffolds and cells have better histocompatibility. PMID:27523994

  20. Photopolymerization of cell-encapsulating hydrogels: crosslinking efficiency versus cytotoxicity.

    Science.gov (United States)

    Mironi-Harpaz, Iris; Wang, Dennis Yingquan; Venkatraman, Subbu; Seliktar, Dror

    2012-05-01

    Cell-encapsulating hydrogels used in regenerative medicine are designed to undergo a rapid liquid-to-solid phase transition in the presence of cells and tissues so as to maximize crosslinking and minimize cell toxicity. Light-activated free-radical crosslinking (photopolymerization) is of particular interest in this regard because it can provide rapid reaction rates that result in uniform hydrogel properties with excellent temporal and spatial control features. Among the many initiator systems available for photopolymerization, only a few have been identified as suitable for cell-based hydrogel formation owing to their water solubility, crosslinking properties and non-toxic reaction conditions. In this study, three long-wave ultraviolet (UV) light-activtied photoinitiators (PIs) were comparatively tested in terms of cytotoxicity, crosslinking efficiency and crosslinking kinetics of cell-encapsulating hydrogels. The hydrogels were photopolymerized from poly(ethylene glycol) (PEG) diacrylate or PEG-fibrinogen precursors using Irgacure® PIs I2959, I184 and I651, as well as with a chemical initiator/accelerator (APS/TEMED). The study specifically evaluated the PI type, PI concentration and UV light intensity, and how these affected the mechanical properties of the hydrogel (i.e. maximum storage modulus), the crosslinking reaction times and the reaction's cytotoxicity to encapsulated cells. Only two initiators (I2959 and I184) were identified as being suitable for achieving both high cell viability and efficient crosslinking of the cell-encapsulating hydrogels during the photopolymerization reaction. Optimization of PI concentration or irradiation intensity was particularly important for achieving maximum mechanical properties; a sub-optimal choice of PI concentration or irradiation intensity resulted in a substantial reduction in hydrogel modulus. Cytocompatibility may be compromised by unnecessarily prolonging exposure to cytotoxic free radicals or inadvertently

  1. Evaluation of biodegradable electric conductive tube-guidesand mesenchymal stem cells

    Institute of Scientific and Technical Information of China (English)

    2015-01-01

    AIM To study the therapeutic effect of three tubeguideswith electrical conductivity associated tomesenchymal stem cells (MSCs) on neuro-muscularregeneration after neurotmesis.METHODS: Rats with 10-mm gap nerve injury weretested using polyvinyl alcohol (PVA), PVA-carbonnanotubes (CNTs) and MSCs, and PVA-polypyrrole(PPy). The regenerated nerves and tibialis anteriormuscles were processed for stereological studies after20 wk. The functional recovery was assessed serially forgait biomechanical analysis, by extensor postural thrust,sciatic functional index and static sciatic functional index (SSI), and by withdrawal reflex latency (WRL). Invitro studies included cytocompatibility, flow cytometry,reverse transcriptase polymerase chain reaction andkaryotype analysis of the MSCs. Histopathology of lung,liver, kidneys, and regional lymph nodes ensured thebiomaterials biocompatibility.RESULTS: SSI remained negative throughout andindependently from treatment. Differences betweentreted groups in the severity of changes in WRL existed,showing a faster regeneration for PVA-CNTs-MSCs (P〈 0.05). At toe-off, less acute ankle joint angles wereseen for PVA-CNTs-MSCs group (P = 0.051) suggestingimproved ankle muscles function during the push offphase of the gait cycle. In PVA-PPy and PVA-CNTsgroups, there was a 25% and 42% increase of averagefiber area and a 13% and 21% increase of the "minimalFeret's diameter" respectively. Stereological analysisdisclosed a significantly (P 〈 0.05) increased myelinthickness (M), ratio myelin thickness/axon diameter (M/d) and ratio axon diameter/fiber diameter (d/D; g-ratio)in PVA-CNT-MSCs group (P 〈 0.05).CONCLUSION: Results revealed that treatmentwith MSCs and PVA-CNTs tube-guides induced betternerve fiber regeneration. Functional and kinematicsanalysis revealed positive synergistic effects brought byMSCs and PVA-CNTs. The PVA-CNTs and PVA-PPy arepromising scaffolds with electric

  2. Modified Titanium Surface-Mediated Effects on Human Bone Marrow Stromal Cell Response

    Directory of Open Access Journals (Sweden)

    Amol Chaudhari

    2013-11-01

    Full Text Available Surface modification of titanium implants is used to enhance osseointegration. The study objective was to evaluate five modified titanium surfaces in terms of cytocompatibility and pro-osteogenic/pro-angiogenic properties for human mesenchymal stromal cells: amorphous microporous silica (AMS, bone morphogenetic protein-2 immobilized on AMS (AMS + BMP, bio-active glass (BAG and two titanium coatings with different porosity (T1; T2. Four surfaces served as controls: uncoated Ti (Ti, Ti functionalized with BMP-2 (Ti + BMP, Ti surface with a thickened titanium oxide layer (TiO2 and a tissue culture polystyrene surface (TCPS. The proliferation of eGFP-fLuc (enhanced green fluorescence protein-firefly luciferase transfected cells was tracked non-invasively by fluorescence microscopy and bio-luminescence imaging. The implant surface-mediated effects on cell differentiation potential was tracked by determination of osteogenic and angiogenic parameters [alkaline phosphatase (ALP; osteocalcin (OC; osteoprotegerin (OPG; vascular endothelial growth factor-A (VEGF-A]. Unrestrained cell proliferation was observed on (unfunctionalized Ti and AMS surfaces, whereas BAG and porous titanium coatings T1 and T2 did not support cell proliferation. An important pro-osteogenic and pro-angiogenic potential of the AMS + BMP surface was observed. In contrast, coating the Ti surface with BMP did not affect the osteogenic differentiation of the progenitor cells. A significantly slower BMP-2 release from AMS compared to Ti supports these findings. In the unfunctionalized state, Ti was found to be superior to AMS in terms of OPG and VEGF-A production. AMS is suggested to be a promising implant coating material for bioactive agents delivery.

  3. Experimental and clinical studies of sup(99m)Tc-pyrophosphate in bone up-take in process of fracture-healing

    International Nuclear Information System (INIS)

    sup(99m)Tc-pyrophosphate (PYP) was given intravenously to rabbits from 3 days to 50 weeks following fracture of the uni-lateral tibia, and the scintigram of bilateral tibias was taken 2 hours following the injection. A ratio of RI accumulation in each site of the tibia was also measured. RI accumulation in fractured site of rabbits increased rapidly one week following the fracture, and decreased after showing its peak three weeks later. The ratio of the RI counts in periosteum of the fractured site one week following the fracture was numerous. However, this was caused by hypertrophy of periosteum itself. The ratio of the counts in bone cortex of the fractured site three weeks following the fracture was numerous, and the ratio of RI accumulation per unit weight showed the maximum value. It was ascertained that the ratio of RI accumulation in the fractured site of rabbits, which were made to postpone the fracture-healing by adding stimulation from outside, had been high since one week following the fracture, and it continued to increase. Change of the ratio of RI accumulation in each fractured site in process of the time almost ran parallel to the rise and fall of the distribution of alkaline phosphatase detected histologically. The ratio of RI accumulation in the fractured site of clinical cases showed the highest valve of 2.8-6.1 three to six months following the fracture, and it was thought to be normal that this highest valve decreased to normal valve ten months following the fracture. (Tsunoda, M.)

  4. Mesenchymal stem cell responses to bone-mimetic electrospun matrices composed of polycaprolactone, collagen I and nanoparticulate hydroxyapatite.

    Directory of Open Access Journals (Sweden)

    Matthew C Phipps

    Full Text Available The performance of biomaterials designed for bone repair depends, in part, on the ability of the material to support the adhesion and survival of mesenchymal stem cells (MSCs. In this study, a nanofibrous bone-mimicking scaffold was electrospun from a mixture of polycaprolactone (PCL, collagen I, and hydroxyapatite (HA nanoparticles with a dry weight ratio of 50/30/20 respectively (PCL/col/HA. The cytocompatibility of this tri-component scaffold was compared with three other scaffold formulations: 100% PCL (PCL, 100% collagen I (col, and a bi-component scaffold containing 80% PCL/20% HA (PCL/HA. Scanning electron microscopy, fluorescent live cell imaging, and MTS assays showed that MSCs adhered to the PCL, PCL/HA and PCL/col/HA scaffolds, however more rapid cell spreading and significantly greater cell proliferation was observed for MSCs on the tri-component bone-mimetic scaffolds. In contrast, the col scaffolds did not support cell spreading or survival, possibly due to the low tensile modulus of this material. PCL/col/HA scaffolds adsorbed a substantially greater quantity of the adhesive proteins, fibronectin and vitronectin, than PCL or PCL/HA following in vitro exposure to serum, or placement into rat tibiae, which may have contributed to the favorable cell responses to the tri-component substrates. In addition, cells seeded onto PCL/col/HA scaffolds showed markedly increased levels of phosphorylated FAK, a marker of integrin activation and a signaling molecule known to be important for directing cell survival and osteoblastic differentiation. Collectively these results suggest that electrospun bone-mimetic matrices serve as promising degradable substrates for bone regenerative applications.

  5. Mesenchymal stem cells and collagen patches for anteriorcruciate ligament repair

    Institute of Scientific and Technical Information of China (English)

    Benjamin Gantenbein; Neha Gadhari; Samantha CW Chan; Sandro Kohl; Sufian S Ahmad

    2015-01-01

    AIM To investigate collagen patches seeded withmesenchymal stem cells (MSCs) and/or tenocytes (TCs)with regards to their suitability for anterior cruciateligament (ACL) repair.METHODS: Dynamic intraligamentary stabilizationutilizes a dynamic screw system to keep ACL remnantsin place and promote biological healing, supplementedby collagen patches. How these scaffolds interact withcells and what type of benefit they provide has not yetbeen investigated in detail. Primary ACL-derived TCsand human bone marrow derived MSCs were seededonto two different types of 3D collagen scaffolds,Chondro-Gide? (CG) and Novocart? (NC). Cells wereseeded onto the scaffolds and cultured for 7 d eitheras a pure populations or as "premix" containing a 1:1ratio of TCs to MSCs. Additionally, as controls, cells wereseeded in monolayers and in co-cultures on both sidesof porous high-density membrane inserts (0.4 μm). Weanalyzed the patches by real time polymerase chainreaction, glycosaminoglycan (GAG), DNA and hydroxyproline(HYP) content. To determine cell spreadingand adherence in the scaffolds microscopic imagingtechniques, i.e. , confocal laser scanning microscopy(cLSM) and scanning electron microscopy (SEM), wereapplied.RESULTS: CLSM and SEM imaging analysis confirmedcell adherence onto scaffolds. The metabolic cellactivity revealed that patches promote adherenceand proliferation of cells. The most dramatic increasein absolute metabolic cell activity was measuredfor CG samples seeded with tenocytes or a 1:1 cellpremix. Analysis of DNA content and cLSM imagingalso indicated MSCs were not proliferating as nicely astenocytes on CG. The HYP to GAG ratio significantlychanged for the premix group, resulting from a slightlylower GAG content, demonstrating that the cells aremodifying the underlying matrix. Real-time quantitative Gantenbein B et al . Mesenchymal stem cells for ACL repair polymerase chain reaction data indicated that MSCs

  6. Fabrication, bioactivity, in vitro cytotoxicity and cell viability of cryo-treated nanohydroxyapatite–gelatin–polyvinyl alcohol macroporous scaffold

    Directory of Open Access Journals (Sweden)

    Sanjaya Kumar Swain

    2014-09-01

    Full Text Available Freeze casting and cryogenic treatment both low temperature process have been employed to fabricate nanobiocomposite hydroxyapatite (HA–gelatin–polyvinyl alcohol (PVA macroporous scaffolds from synthesized three different spherical, rod and fibrous HA nanoparticles and composition optimized vis-á-vis porosity architecture, content and compressive strength. A critical HA morphology, solid loading and liquid nitrogen interaction time have a significant effect to enhance the mechanical response of developed scaffolds. Cryo-treated 40 wt.% nanorod HA–gelatin–PVA scaffold posses interconnected pore structure with 80 vol.% porosity, average pore diameter 50–200 μm and highest 5.8 MPa compressive strength. Different degree of the apatite deposition phenomenon in simulated body fluid solution at 37 °C and pH ∼ 7.4 varies with respect to time. In vitro cytotoxicity and L929 mouse fibroblast cell culture in the presence of Dulbecco's Modified Eagle Medium and 10% Fetal Bovine Serum at 37 °C and 5% CO2 atmosphere exhibit excellent cytocompatibility and cell viability at low extract concentration up to 25%.

  7. Transition from Bioinert to Bioactive Material by Tailoring the Biological Cell Response to Carboxylated Nanocellulose.

    Science.gov (United States)

    Hua, Kai; Rocha, Igor; Zhang, Peng; Gustafsson, Simon; Ning, Yi; Strømme, Maria; Mihranyan, Albert; Ferraz, Natalia

    2016-03-14

    This work presents an insight into the relationship between cell response and physicochemical properties of Cladophora cellulose (CC) by investigating the effect of CC functional group density on the response of model cell lines. CC was carboxylated by electrochemical TEMPO-mediated oxidation. By varying the amount of charge passed through the electrolysis setup, CC materials with different degrees of oxidation were obtained. The effect of carboxyl group density on the material's physicochemical properties was investigated together with the response of human dermal fibroblasts (hDF) and human osteoblastic cells (Saos-2) to the carboxylated CC films. The introduction of carboxyl groups resulted in CC films with decreased specific surface area and smaller total pore volume compared with the unmodified CC (u-CC). While u-CC films presented a porous network of randomly oriented fibers, a compact and aligned fiber pattern was depicted for the carboxylated-CC films. The decrease in surface area and total pore volume, and the orientation and aggregation of the fibers tended to augment parallel to the increase in the carboxyl group density. hDF and Saos-2 cells presented poor cell adhesion and spreading on u-CC, which gradually increased for the carboxylated CC as the degree of oxidation increased. It was found that a threshold value in carboxyl group density needs be reached to obtain a carboxylated-CC film with cytocompatibility comparable to commercial tissue culture material. Hence, this study demonstrates that a normally bioinert nanomaterial can be rendered bioactive by carefully tuning the density of charged groups on the material surface, a finding that not only may contribute to the fundamental understanding of biointerface phenomena, but also to the development of bioinert/bioactive materials. PMID:26886265

  8. Gelatin modified ultrathin silk fibroin films for enhanced proliferation of cells.

    Science.gov (United States)

    Yang, Luyuan; Yaseen, Mohammed; Zhao, Xiubo; Coffey, Paul; Pan, Fang; Wang, Yuming; Xu, Hai; Webster, John; Lu, Jian R

    2015-04-01

    Silk fibroin (SF) films were modified with gelatin (G) to explore if such SF/G films could enhance the surface biocompatibility of silk as cell growth biomaterials. Ultrathin films were coated from aqueous SF solutions pre-mixed with different amounts of G. It was found that the SF/G blended films after methanol treatment were highly stable in physiological conditions. The incorporation of G smoothed the surface morphology of the SF/G films formed. Surface-exposed RGD sequences were successfully identified on the SF/G films through specific recognition of an integrin-mimicking peptide (bearing the sequence of CWDDGWLC). Cell culture experiments with 3T3 fibroblasts demonstrated that SF/G films with 1.2-20% (w/w) G gave clear improvement in promoting cell attachment and proliferation over pure SF films. Films containing 10-20% (w/w) of G showed cell attachment and growth even superior to the pure G films. The differences as observed from this study suggest that due to the lack of mechanical strength associated with its high solubility, G could not work alone as a cell growth scaffold. The enhanced cellular responses from the blended SF/G films must result from improvement in film stability arising from SF and in cytocompatibility arising from G. The results thus indicate the potential of the SF/G blends in tissue engineering and biomedical engineering where physical and biological properties could be manipulated via mixing either as bulk biomaterials or for coating purposes. PMID:25784671

  9. Gold nanoparticle size and shape influence on osteogenesis of mesenchymal stem cells

    Science.gov (United States)

    Li, Jingchao; Li, Jia'en Jasmine; Zhang, Jing; Wang, Xinlong; Kawazoe, Naoki; Chen, Guoping

    2016-04-01

    Gold nanoparticles (AuNPs) have been extensively explored for biomedical applications due to their advantages of facile synthesis and surface functionalization. Previous studies have suggested that AuNPs can induce differentiation of stem cells into osteoblasts. However, how the size and shape of AuNPs affect the differentiation response of stem cells has not been elucidated. In this work, a series of bovine serum albumin (BSA)-coated Au nanospheres, Au nanostars and Au nanorods with different diameters of 40, 70 and 110 nm were synthesized and their effects on osteogenic differentiation of human mesenchymal stem cells (hMSCs) were investigated. All the AuNPs showed good cytocompatibility and did not influence proliferation of hMSCs at the studied concentrations. Osteogenic differentiation of hMSCs was dependent on the size and shape of AuNPs. Sphere-40, sphere-70 and rod-70 significantly increased the alkaline phosphatase (ALP) activity and calcium deposition of cells while rod-40 reduced the ALP activity and calcium deposition. Gene profiling revealed that the expression of osteogenic marker genes was down-regulated after incubation with rod-40. However, up-regulation of these genes was found in the sphere-40, sphere-70 and rod-70 treatment. Moreover, it was found that the size and shape of AuNPs affected the osteogenic differentiation of hMSCs through regulating the activation of Yes-associated protein (YAP). These results indicate that the size and shape of AuNPs had an influence on the osteogenic differentiation of hMSCs, which should provide useful guidance for the preparation of AuNPs with defined size and shape for their biomedical applications.Gold nanoparticles (AuNPs) have been extensively explored for biomedical applications due to their advantages of facile synthesis and surface functionalization. Previous studies have suggested that AuNPs can induce differentiation of stem cells into osteoblasts. However, how the size and shape of AuNPs affect the

  10. Anticoagulation and endothelial cell behaviors of heparin-loaded graphene oxide coating on titanium surface.

    Science.gov (United States)

    Pan, Chang-Jiang; Pang, Li-Qun; Gao, Fei; Wang, Ya-Nan; Liu, Tao; Ye, Wei; Hou, Yan-Hua

    2016-06-01

    Owing to its unique physical and chemical properties, graphene oxide (GO) has attracted tremendous interest in many fields including biomaterials and biomedicine. The purpose of the present study is to investigate the endothelial cell behaviors and anticoagulation of heparin-loaded GO coating on the titanium surface. To this end, the titanium surface was firstly covered by the polydopamine coating followed by the deposition of the GO coating. Heparin was finally loaded on the GO coating to improve the blood compatibility. The results of attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR), Raman spectroscopy and X-ray photoelectron spectroscopy (XPS) indicated that the heparin-loaded GO coating was successfully created on the titanium surface. The scanning electron microscopy (SEM) images indicated that a relative uniform GO coating consisting of multilayer GO sheets was formed on the substrate. The hydrophilicity of the titanium surface was enhanced after the deposition of GO and further improved significantly by the loading heparin. The GO coating can enhance the endothelial cell adhesion and proliferation as compared with polydopamine coating and the blank titanium. Loading heparin on the GO coating can significantly reduce the platelet adhesion and prolong the activated partial thromboplastin time (APTT) while not influence the endothelial cell adhesion and proliferation. Therefore, the heparin-loaded GO coating can simultaneously enhance the cytocompatibility to endothelial cells and blood compatibility of biomaterials. Because the polydopamine coating can be easily prepared on most of biomaterials including polymer, ceramics and metal, thus the approach of the present study may open up a new window of promising an effective and efficient way to promote endothelialization and improve the blood compatibility of blood-contact biomedical devices such as intravascular stents. PMID:27040227

  11. Induction of Apoptosis by Green Synthesized Gold Nanoparticles Through Activation of Caspase-3 and 9 in Human Cervical Cancer Cells

    Science.gov (United States)

    Baharara, Javad; Ramezani, Tayebe; Divsalar, Adeleh; Mousavi, Marzieh; Seyedarabi, Arefeh

    2016-01-01

    Background: Gold Nanoparticles (GNPs) are used in imaging and molecular diagnostic applications. As the development of a novel approach in the green synthesis of metal nanoparticles is of great importance and a necessity, a simple and safe method for the synthesis of GNPs using plant extracts of Zataria multiflora leaves was applied in this study and the results on GNPs’ anticancer activity against HeLa cells were reported. Methods: The GNPs were characterized by UV-visible spectroscopy, FTIR, TEM, DLS and Zeta-potential measurements. In addition, the cellular up-take of nanoparticles was investigated using Dark Field Microscopy (DFM). Induction of apoptosis by high dose of GNPs in HeLa cells was assessed by MTT assay, Acridin orange, DAPI staining, Annexin V/PI double-labeling flow cytometry and caspase activity assay. Results: UV-visible spectroscopy results showed a surface plasmon resonance band for GNPs at 530 nm. FTIR results demonstrated an interaction between plant extract and nanoparticles. TEM images revealed different shapes for GNPs and DLS results indicated that the GNPs range in size from 10 to 42 nm. The Zeta potential values of the synthesized GNPs were between 30 to 50 Mev, indicating the formation of stable particles. As evidenced by MTT assay, GNPs inhibit proliferation of HeLa cells in dose-dependent GNPs and cytotoxicity of GNPs in Bone Marrow Mesenchymal Stem Cell (BMSCs) was lower than cancerous cells. At nontoxic concentrations, the cellular up-take of the nanoparticles took place. Acridin orange and DAPI staining showed morphological changes in the cell’s nucleus due to apoptosis. Finally, caspase activity assay demonstrated HeLa cell’s apoptosis through caspase activation. Conclusion: The results showed that GNPs have the ability to induce apoptosis in HeLa cells. PMID:27141266

  12. Self-Powered Electrical Stimulation for Enhancing Neural Differentiation of Mesenchymal Stem Cells on Graphene-Poly(3,4-ethylenedioxythiophene) Hybrid Microfibers.

    Science.gov (United States)

    Guo, Weibo; Zhang, Xiaodi; Yu, Xin; Wang, Shu; Qiu, Jichuan; Tang, Wei; Li, Linlin; Liu, Hong; Wang, Zhong Lin

    2016-05-24

    Engineered conductive scaffolds toward neural regeneration should have the ability to regulate mesenchymal stems cell (MSC) differentiation into neural lineage through an electrical stimulation-assisted culture process. In this work, a self-powered electrical stimulation-assisted neural differentiation system for MSCs was realized by combining a high effective triboelectric nanogenerator (TENG) to supply pulsed electric simulation signals and a poly(3,4-ethylenedioxythiophene) (PEDOT)-reduced graphene oxide (rGO) hybrid microfiber (80 μm in diameter) as a scaffold. The conductive PEDOT endows the rGO-PEDOT hybrid microfiber with an enhanced electrical conductivity and maintains a good cytocompatibility. MSCs cultured on this highly conductive rGO-PEDOT hybrid microfiber possess enhanced proliferation ability and good neural differentiation tendency. Importantly, by inducing electric pulses generated by the TENG as the electrical stimulation signal, which are triggered by human walking steps, neural differentiation of MSCs is dramatically improved. This study illustrates the customizability of the rGO-PEDOT hybrid microfiber for neural tissue engineering scaffolding applications, underlines the potential of a self-powered TENG electrical stimulation system for accelerating MSC differentiation into neural cells without bio/chemical cues, and suggests the TENG's practical use as a wearable stimulation system to assist nerve regeneration for a walking person. PMID:27144593

  13. Preparation, characterisation, and in vitro evaluation of electrically conducting poly(ɛ-caprolactone)-based nanocomposite scaffolds using PC12 cells.

    Science.gov (United States)

    Gopinathan, Janarthanan; Quigley, Anita F; Bhattacharyya, Amitava; Padhye, Rajiv; Kapsa, Robert M I; Nayak, Rajkishore; Shanks, Robert A; Houshyar, Shadi

    2016-04-01

    In the current study, we describe the synthesis, material characteristics, and cytocompatibility of conducting poly (ɛ-caprolactone) (PCL)-based nano-composite films. Electrically conducting carbon nano-fillers (carbon nano-fiber (CNF), nano-graphite (NG), and liquid exfoliated graphite (G)) were used to prepare porous film type scaffolds using modified solvent casting methods. The electrical conductivity of the nano-composite films was increased when carbon nano-fillers were incorporated in the PCL matrix. CNF-based nano-composite films showed the highest increase in electrical conductivity. The presence of an ionic solution significantly improved the conductivity of some of the polymers, however at least 24 h was required to absorb the simulated ion solutions. CNF-based nano-composite films were found to have good thermo-mechanical properties compared to other conducting polymer films due to better dispersion and alignment in the critical direction. Increased nano-filler content increased the crystallisation temperature. Analysis of cell viability revealed no increase in cell death on any of the polymers compared to tissue culture plastic controls, or compared to PCL polymer without nano-composites. The scaffolds showed some variation when tested for PC12 cell attachment and proliferation, however all the polymers supported PC12 attachment and differentiation in the absence of cell adhesion molecules. In general, CNF-based nano-composite films with highest electrical conductivity and moderate roughness showed highest cell attachment and proliferation. These polymers are promising candidates for use in neural applications in the area of bionics and tissue engineering due to their unique properties. PMID:26646762

  14. Characterization and anticancer potential of ferulic acid-loaded chitosan nanoparticles against ME-180 human cervical cancer cell lines

    Science.gov (United States)

    Panwar, Richa; Sharma, Asvene K.; Kaloti, Mandeep; Dutt, Dharm; Pruthi, Vikas

    2015-10-01

    Ferulic acid (FA) is a widely distributed hydroxycinnamic acid found in various cereals and fruits exhibiting potent antioxidant and anticancer activities. However, due to low solubility and permeability, its availability to biological systems is limited. Non-toxic chitosan-tripolyphosphate pentasodium (CS-TPP) nanoparticles (NPs) are used to load sparingly soluble molecules and drugs, increasing their bioavailability. In the present work, we have encapsulated FA into the CS-TPP NPs to increase its potential as a therapeutic agent. Different concentrations of FA were tested to obtain optimum sized FA-loaded CS-TPP nanoparticles (FA/CS-TPP NPs) by ionic gelation method. Nanoparticles were characterized by scanning electron microscopy, Fourier transformation infrared spectroscopy (FTIR), thermogravimetric analyses and evaluated for their anticancer activity against ME-180 human cervical cancer cell lines. The FTIR spectra confirmed the encapsulation of FA and thermal analysis depicted its degradation profile. A concentration-dependent relationship between FA encapsulation efficiency and FA/CS-TPP NPs diameter was observed. Smooth and spherical FA-loaded cytocompatible nanoparticles with an average diameter of 125 nm were obtained at 40 µM FA conc. The cytotoxicity of 40 µM FA/CS-TPP NPs against ME-180 cervical cancer cell lines was found to be higher as compared to 40 µM native FA. Apoptotic morphological changes as cytoplasmic remnants and damaged wrinkled cells in ME-180 cells were visualized using scanning electron microscopic and fluorescent microscopic techniques. Data concluded that chitosan enveloped FA nanoparticles could be exploited as an excellent therapeutic drug against cancer cells proliferation.

  15. TiO{sub 2}-enriched polymeric powder coatings support human mesenchymal cell spreading and osteogenic differentiation

    Energy Technology Data Exchange (ETDEWEB)

    Mozumder, Mohammad Sayem; Zhu, Jesse [Department of Chemical and Biochemical Engineering, University of Western Ontario, London, Ontario, N6A 5B9 (Canada); Perinpanayagam, Hiran, E-mail: Hiran.Perinpanayagam@schulich.uwo.ca [Schulich School of Medicine and Dentistry, University of Western Ontario, London, Ontario, N6A 5C1 (Canada)

    2011-06-15

    Novel polymeric powder coatings (PPC) were prepared by ultrafine powder coating technology and shown to support human mesenchymal cell attachment and growth. PPC surfaces enriched with nano-TiO{sub 2} (nTiO{sub 2}) showed enhanced cellular responses, and were compared to commercially pure titanium (cpTi). After cell attachment and growth, osteogenic differentiation and bone matrix formation ensures osseointegration for implantable biomaterials. Therefore, the objective of this study was to determine if mesenchymal cells grown on PPC could undergo osteogenic differentiation by inducing Runx2 and bone matrix proteins, and then initiate mineralization. Atomic force microscopy revealed intricate three-dimensional micro-topographies, and the measures of nano-roughness and porosity were similar for all PPC surfaces. Scanning electron microscopy showed that the cells attached and spread out over all of the surfaces. After 1 week in osteogenic media, RT-PCR analysis showed the induction of Runx2, the up-regulation of type I collagen, and the initial detection of alkaline phosphatase and bone sialoprotein. After 4 weeks, Alizarin Red staining showed mineral deposition. However, cell spreading and osteogenic differentiation were significantly (P < 0.05) higher on the cpTi controls than on the PPC surfaces. Furthermore, spreading and differentiation were consistently higher on the titanium-enriched PPC-2, -3 and -4 than on the titanium-free PPC-1. Therefore, despite the presence of complex micro-topographies and nano-features, titanium-enrichment enhanced the cellular response, and pure titanium still provided the best substrate. These findings confirm the cytocompatibility of these novel polymeric coatings and suggest that titanium-enrichment and nTiO{sub 2} additives may enhance their performance.

  16. Characterization and anticancer potential of ferulic acid-loaded chitosan nanoparticles against ME-180 human cervical cancer cell lines

    Science.gov (United States)

    Panwar, Richa; Sharma, Asvene K.; Kaloti, Mandeep; Dutt, Dharm; Pruthi, Vikas

    2016-08-01

    Ferulic acid (FA) is a widely distributed hydroxycinnamic acid found in various cereals and fruits exhibiting potent antioxidant and anticancer activities. However, due to low solubility and permeability, its availability to biological systems is limited. Non-toxic chitosan-tripolyphosphate pentasodium (CS-TPP) nanoparticles (NPs) are used to load sparingly soluble molecules and drugs, increasing their bioavailability. In the present work, we have encapsulated FA into the CS-TPP NPs to increase its potential as a therapeutic agent. Different concentrations of FA were tested to obtain optimum sized FA-loaded CS-TPP nanoparticles (FA/CS-TPP NPs) by ionic gelation method. Nanoparticles were characterized by scanning electron microscopy, Fourier transformation infrared spectroscopy (FTIR), thermogravimetric analyses and evaluated for their anticancer activity against ME-180 human cervical cancer cell lines. The FTIR spectra confirmed the encapsulation of FA and thermal analysis depicted its degradation profile. A concentration-dependent relationship between FA encapsulation efficiency and FA/CS-TPP NPs diameter was observed. Smooth and spherical FA-loaded cytocompatible nanoparticles with an average diameter of 125 nm were obtained at 40 µM FA conc. The cytotoxicity of 40 µM FA/CS-TPP NPs against ME-180 cervical cancer cell lines was found to be higher as compared to 40 µM native FA. Apoptotic morphological changes as cytoplasmic remnants and damaged wrinkled cells in ME-180 cells were visualized using scanning electron microscopic and fluorescent microscopic techniques. Data concluded that chitosan enveloped FA nanoparticles could be exploited as an excellent therapeutic drug against cancer cells proliferation.

  17. Stem Cells

    Science.gov (United States)

    Stem cells are cells with the potential to develop into many different types of cells in the body. ... the body. There are two main types of stem cells: embryonic stem cells and adult stem cells. Stem ...

  18. Radioprotection of mouse CNS endothelial cells in vivo

    Energy Technology Data Exchange (ETDEWEB)

    Lyubimova, N.; Coultas, P.; Martin, R. [Peter McCallum Cancer Institute, Melbourne, VIC (Australia)

    1996-12-31

    Full text: Radioprotection using the minor groove binding DNA ligand Hoechst 33342 has been demonstrated in vitro, and more recently in vivo, in mouse lung. Intravenous administration was used for the lung studies, and both endothelial and alveolar epithelial cells-showed good up-take. Radiation damage to the endothelial cell population has also been postulated as important in late developing radionecrosis of spinal cord and brain. Endothelial cell density in brain can be readily determined by a fluorescent-histochemical technique. Treatment with a monoamine oxidase inhibitor and subsequent injection with L-DOPA results in an accumulation of dopamine (DA) in CNS endothelial cells. DA is converted to a fluorophore by exposure to paraformaldehyde, and cell numbers assayed by fluorescence microscopy. Earlier studies used this technique to monitor post-irradiation changes in endothelial cell density in rodent brain and showed the loss, within 24 hours, of a sensitive subpopulation comprising about 15% of the endothelial cells. Ten minutes after intravenous injection of Hoechst 33342 (80mg/kg) the ligand is confined by its limited penetration to the endothelial cells in mouse brain. When we irradiated at this time, there was protection against early endothelial cell loss. Ablation of the sensitive subpopulation in unprotected mice takes place over a dose range of 1 to 3 Gy {gamma}-rays, but doses between 12 to 20 Gy are required in the presence of ligand. This protection equates to a very high dose modification factor of about 7 and possibly reflects a suppression of apoptosis in the sensitive endothelial subpopulation. The extent to which there is enhanced survival in the endothelial population as a whole and how the observed protection affects late CNS necrosis development has yet to be determined. However present results clearly show potential for the use of DNA-binding radioprotectors with limited penetration for investigations into the relative significance of

  19. Mg ion implantation on SLA-treated titanium surface and its effects on the behavior of mesenchymal stem cell

    International Nuclear Information System (INIS)

    Magnesium (Mg) is one of the most important ions associated with bone osseointegration. The aim of this study was to evaluate the cellular effects of Mg implantation in titanium (Ti) surfaces treated with sand blast using large grit and acid etching (SLA). Mg ions were implanted into the surface via vacuum arc source ion implantation. The surface morphology, chemical properties, and the amount of Mg ion release were evaluated by scanning electron microscopy (SEM), Auger electron spectroscopy (AES), Rutherford backscattering spectroscopy (RBS), and inductively coupled plasma-optical emission spectrometer (ICP-OES). Human mesenchymal stem cells (hMSCs) were used to evaluate cellular parameters such as proliferation, cytotoxicity, and adhesion morphology by MTS assay, live/dead assay, and SEM. Furthermore, osteoblast differentiation was determined on the basis of alkaline phosphatase (ALP) activity and the degree of calcium accumulation. In the Mg ion-implanted disk, 2.3 × 1016 ions/cm2 was retained. However, after Mg ion implantation, the surface morphology did not change. Implanted Mg ions were rapidly released during the first 7 days in vitro. The MTS assay, live/dead assay, and SEM demonstrated increased cell attachment and growth on the Mg ion-implanted surface. In particular, Mg ion implantation increased the initial cell adhesion, and in an osteoblast differentiation assay, ALP activity and calcium accumulation. These findings suggest that Mg ion implantation using the plasma source ion implantation (PSII) technique may be useful for SLA-treated Ti dental implants to improve their osseointegration capacity. - Highlights: ► Mg ion was coated onto surface of SLA treated titanium via vacuum arc source ion implantation method. ► The morphological characteristics did not change after Mg ion implantation. ► Mg ion implanted SLA Ti is highly cytocompatible. ► Initial cell adhesion of MSCs is improved by Mg ion implantation. ► Mg ion implantation improved

  20. Mg ion implantation on SLA-treated titanium surface and its effects on the behavior of mesenchymal stem cell

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Beom-Su; Kim, Jin Seong [Wonkwang Bone Regeneration Research Institute, Wonkwang University, Iksan 570-749 (Korea, Republic of); Bonecell Biotech Inc., 77, Dunsan-ro, Seo-gu, Daejeon 302-830 (Korea, Republic of); Park, Young Min [DIO Corporation, 66, Centum seo-ro, Haeundae-gu, Busan (Korea, Republic of); Choi, Bo-Young [Department of Oral and maxillofacial Surgery, Wonkwang University Daejeon Dental Hospital, Daejeon 302-830 (Korea, Republic of); Lee, Jun, E-mail: omslee@wku.ac.kr [Wonkwang Bone Regeneration Research Institute, Wonkwang University, Iksan 570-749 (Korea, Republic of); Bonecell Biotech Inc., 77, Dunsan-ro, Seo-gu, Daejeon 302-830 (Korea, Republic of)

    2013-04-01

    Magnesium (Mg) is one of the most important ions associated with bone osseointegration. The aim of this study was to evaluate the cellular effects of Mg implantation in titanium (Ti) surfaces treated with sand blast using large grit and acid etching (SLA). Mg ions were implanted into the surface via vacuum arc source ion implantation. The surface morphology, chemical properties, and the amount of Mg ion release were evaluated by scanning electron microscopy (SEM), Auger electron spectroscopy (AES), Rutherford backscattering spectroscopy (RBS), and inductively coupled plasma-optical emission spectrometer (ICP-OES). Human mesenchymal stem cells (hMSCs) were used to evaluate cellular parameters such as proliferation, cytotoxicity, and adhesion morphology by MTS assay, live/dead assay, and SEM. Furthermore, osteoblast differentiation was determined on the basis of alkaline phosphatase (ALP) activity and the degree of calcium accumulation. In the Mg ion-implanted disk, 2.3 × 10{sup 16} ions/cm{sup 2} was retained. However, after Mg ion implantation, the surface morphology did not change. Implanted Mg ions were rapidly released during the first 7 days in vitro. The MTS assay, live/dead assay, and SEM demonstrated increased cell attachment and growth on the Mg ion-implanted surface. In particular, Mg ion implantation increased the initial cell adhesion, and in an osteoblast differentiation assay, ALP activity and calcium accumulation. These findings suggest that Mg ion implantation using the plasma source ion implantation (PSII) technique may be useful for SLA-treated Ti dental implants to improve their osseointegration capacity. - Highlights: ► Mg ion was coated onto surface of SLA treated titanium via vacuum arc source ion implantation method. ► The morphological characteristics did not change after Mg ion implantation. ► Mg ion implanted SLA Ti is highly cytocompatible. ► Initial cell adhesion of MSCs is improved by Mg ion implantation. ► Mg ion implantation

  1. The effects of Ca{sub 2}SiO{sub 4}–Ca{sub 3}(PO{sub 4}){sub 2} ceramics on adult human mesenchymal stem cell viability, adhesion, proliferation, differentiation and function

    Energy Technology Data Exchange (ETDEWEB)

    De Aza, Piedad N., E-mail: piedad@umh.es [Instituto de Bioingeniería, Universidad Miguel Hernández, Avda. Universidad s/n, 03202 Elche, Alicante (Spain); García-Bernal, David, E-mail: redond@gmail.com [Centro Integrado de Investigación Biomédica (CEIB), Universidad de Murcia, 30120 Murcia (Spain); Cragnolini, Francesca, E-mail: dott.ssa_franci@hotmail.it [Centro Integrado de Investigación Biomédica (CEIB), Universidad de Murcia, 30120 Murcia (Spain); Velasquez, Pablo, E-mail: pvlasquez@umh.es [Instituto de Bioingeniería, Universidad Miguel Hernández, Avda. Universidad s/n, 03202 Elche, Alicante (Spain); Meseguer-Olmo, Luis, E-mail: lmeseguer.doc@gmail.com [Centro Integrado de Investigación Biomédica (CEIB), Universidad de Murcia, 30120 Murcia (Spain); Unidad de Bioingeniería ósea, Servicio de Cirugía Ortopédica, Hospital Universitario Virgen de la Arrixaca, Universidad de Murcia, 30120 Murcia (Spain)

    2013-10-15

    Bioceramic samples with osteogenic properties, suitable for use in the regeneration of hard tissue, were synthesized. The materials consisting of α-tricalcium phosphate (αTCP) and also αTCP doped with either 1.5 wt.% or 3.0 wt.% of dicalcium silicate (C{sub 2}S) in the system Dicalcium Silicate–Tricalcium Phosphate (C{sub 2}S–TCP) were obtained by solid state reaction. All materials were composed of a single phase, αTCP in the case of a pure material, or solid solution of C{sub 2}S in αTCP (αTCPss) for the doped αTCP. Viability, proliferation and in vitro osteoinductive capacity were investigated by seeding, adult mesenchymal stem cells of human origin (ahMSCs) which were CD73{sup +}, CD90{sup +}, CD105{sup +}, CD34{sup −} and CD45{sup −} onto the 3 substrates for 30 days. Results show a non-cytotoxic effect after applying an indirect apoptosis test (Annexin V/7-AAD staining), so ahMSCs adhered, spread, proliferated and produced extracellular matrix (Heparan-sulfate proteoglycan (HS) and osteopontin (OP)) on all the ceramics studied. Finally, the cells lost the cluster differentiation marker expression CD73, CD90 y CD105 characteristic of ahMSCs and they showed an osteoblastic phenotype (Alkaline phosphatase activity (ALP), Osteocalcin production (OC), Collagen type I expression (Col-I), and production of mineralization nodules on the extracellular matrix). These observations were more evident in the αTCP ceramic doped with 1.5 wt.% C{sub 2}S, indicating osteoblastic differentiation as a result of the increased concentration of solid solution of C{sub 2}S in αTCP (αTCPss). Overall, these results suggest that the ceramics studied are cytocompatible and they are able to induce osteoblastic differentiation of undifferentiated ahMSCs. - Highlights: • The ceramics studied are cytocompatible and show osteoinductive properties. • Results show a non-cytotoxic effect after applying an indirect apoptosis test. • ahMSCs adhered, spread, proliferated

  2. Effect of lithium on iodine uptake in thyroid cells in cultures

    International Nuclear Information System (INIS)

    In order to elucidate the mechanism of action of lithium on the thyroid gland, we studied the effect of lithium on the 125I up-take in thyroid cells in vitro. After culturing FRTL-5 cells 7 days in a medium lacking TSH, the cells were incubated with various concentrations of lithium (0.5∼10 mmol/L) and TSH (50, 100 mU/L) for 24 h. Iodide uptake was initiated by adding 500 μl buffered HBSS containing 0.1 μCi carrier-free Na 125I and 10 nmol/L NaI. After incubation, the cells were dissolved and their radioactivities counted. The 125I uptake in FRTL-5 cells rose to peak level in 30 minutes. Prolonging the incubation period did not change the iodide uptake. During the peak phase sodium perchloride suppressed the 125I uptake more than 90%. The iodide uptake induced by TSH was inhibited at 1 mmol/L lithium (P<0.05). More than 50% inhibition was observed at 2∼10 mmol/L lithium. There was no effect of lithium on the iodide uptake in the basal condition of FRTL-5 cells (lacking TSH). Lithium inhibits iodide uptake in thyroid cells in the presence of TSH

  3. Aquated cisplatin and heparin-pluronic nanocomplexes exhibiting sustainable release of active platinum compound and NCI-H460 lung cancer cell antiproliferation.

    Science.gov (United States)

    Tong, Nhat-Anh N; Nguyen, Thi Phuong; Cuu Khoa, Nguyen; Tran, Ngoc Quyen

    2016-06-01

    In recent decades, platinum compounds have been many contributions in medicine. Development of new drugs from the active platinum compounds as well as nanocarriers for targeted delivery and reducing side effects of the drugs has paid much attention. In the study, nanocomplexes were prepared from aquated species of cisplatin and pluronic-conjugated heparin which distributed in the range of 80-100 nm by Transmission Electron Microscopy and 134 nm by Dynamic light scattering (DLS). Formation of the complex was confirmed by FTIR and DLS. The nanocomplexes exhibited high drug-loading capacity (approximately 42.5% wt/wt at 37 °C and 37.5% wt/wt at 25 °C). In vitro, drug-loaded nanogels showed much slower release profiles of cisplatin CDDP in pH 7.4 (physiological pH) compared with pH 5.5 condition at 37 °C. Moreover, the cytotoxicity assay results also indicated that Hep-F127 was cytocompatible; meanwhile, CDDP-loaded nanocomplex was able to reduce the cytotoxic ability of free CDDP (IC50 = 5.68 ± 0.73 μg/ml), which still maintain a significantly antiproliferative activity on NCI-H460 lung cancer cell. The in vitro preliminarily obtained results indicate that the nanocomplex is a candidate for CDDP delivery which can be studied further in cancer therapy. PMID:26886825

  4. Cell Permeating Nano-Complexes of Amphiphilic Polyelectrolytes Enhance Solubility, Stability, and Anti-Cancer Efficacy of Curcumin.

    Science.gov (United States)

    Fatima, Munazza T; Chanchal, Abhishek; Yavvari, Prabhu S; Bhagat, Somnath D; Gujrati, Mansi; Mishra, Ram K; Srivastava, Aasheesh

    2016-07-11

    Many hydrophobic drugs encounter severe bioavailability issues owing to their low aqueous solubility and limited cellular uptake. We have designed a series of amphiphilic polyaspartamide polyelectrolytes (PEs) that solubilize such hydrophobic drugs in aqueous medium and enhance their cellular uptake. These PEs were synthesized through controlled (∼20 mol %) derivatization of polysuccinimide (PSI) precursor polymer with hydrophobic amines (of varying alkyl chain lengths, viz. hexyl, octyl, dodecyl, and oleyl), while the remaining succinimide residues of PSI were opened using a protonable and hydrophilic amine, 2-(2-amino-ethyl amino) ethanol (AE). Curcumin (Cur) was employed as a representative hydrophobic drug to explore the drug-delivery potential of the resulting PEs. Unprecedented enhancement in the aqueous solubility of Cur was achieved by employing these PEs through a rather simple protocol. In the case of PEs containing oleyl/dodecyl residues, up to >65000× increment in the solubility of Cur in aqueous medium could be achieved without requiring any organic solvent at all. The resulting suspensions were physically and chemically stable for at least 2 weeks. Stable nanosized polyelectrolyte complexes (PECs) with average hydrodynamic diameters (DH) of 150-170 nm (without Cur) and 220-270 nm (after Cur loading) were obtained by using submolar sodium polyaspartate (SPA) counter polyelectrolyte. The zeta potential of these PECs ranged from +36 to +43 mV. The PEC-formation significantly improved the cytocompatibility of the PEs while affording reconstitutable nanoformulations having up to 40 wt % drug-loading. The Cur-loaded PECs were readily internalized by mammalian cells (HEK-293T, MDA-MB-231, and U2OS), majorly through clathrin-mediated endocytosis (CME). Cellular uptake of Cur was directly correlated with the length of the alkyl chain present in the PECs. Further, the PECs significantly improved nuclear transport of Cur in cancer cells, resulting in their

  5. Chitosan hydrogels enriched with polyphenols: Antibacterial activity, cell adhesion and growth and mineralization

    Czech Academy of Sciences Publication Activity Database

    Lišková, Jana; Douglas, T.E.L.; Beranová, J.; Skwarczyńska, A.; Božič, M.; Samal, S. K.; Modrzejewska, Z.; Gorgieva, S.; Kokol, V.; Bačáková, Lucie

    2015-01-01

    Roč. 129, Sep 20 (2015), s. 135-142. ISSN 0144-8617 R&D Projects: GA MŠk(CZ) ED1.1.00/02.0109; GA MŠk(CZ) EE2.3.30.0025 Institutional support: RVO:67985823 Keywords : hydrogel * polyphenol * cytocompatibility Subject RIV: EI - Biotechnology ; Bionics Impact factor: 4.074, year: 2014

  6. Multifunctional lactobionic acid-modified dendrimers for targeted drug delivery to liver cancer cells: investigating the role played by PEG spacer.

    Science.gov (United States)

    Fu, Fanfan; Wu, Yilun; Zhu, Jingyi; Wen, Shihui; Shen, Mingwu; Shi, Xiangyang

    2014-09-24

    We report the development of a lactobionic acid (LA)-modified multifunctional dendrimer-based carrier system for targeted therapy of liver cancer cells overexpressing asialoglycoprotein receptors. In this study, generation 5 (G5) poly(amidoamine) (PAMAM) dendrimers were sequentially modified with fluorescein isothiocyanate (FI) and LA (or polyethylene glycol (PEG)-linked LA, PEG-LA), followed by acetylation of the remaining dendrimer terminal amines. The synthesized G5.NHAc-FI-LA or G5.NHAc-FI-PEG-LA conjugates (NHAc denotes acetamide groups) were used to encapsulate a model anticancer drug doxorubicin (DOX). We show that both conjugates are able to encapsulate approximately 5.0 DOX molecules within each dendrimer and the formed dendrimer/DOX complexes are stable under different pH conditions and different aqueous media. The G5.NHAc-FI-PEG-LA conjugate appears to have a better cytocompatibility, enables a slightly faster DOX release rate, and displays better liver cancer cell targeting ability than the G5.NHAc-FI-LA conjugate without PEG under similar experimental conditions. Importantly, the developed G5.NHAc-FI-PEG-LA/DOX complexes are able to specifically inhibit the growth of the target cells with a better efficiency than the G5.NHAc-FI-LA/DOX complexes at a relatively high DOX concentration. Our results suggest a key role played by the PEG spacer that affords the dendrimer platform with enhanced targeting and therapeutic efficacy of cancer cells. The developed LA-modified multifunctional dendrimer conjugate with a PEG spacer may be used as a delivery system for targeted liver cancer therapy and offers new opportunities in the design of multifunctional drug carriers for targeted cancer therapy applications. PMID:25185074

  7. Osteoblast cell behavior on the new beta-type Ti–25Ta–25Nb alloy

    International Nuclear Information System (INIS)

    Among metallic materials used as bone substitutes, β titanium alloys gain an increasing importance because of their low modulus, high corrosion resistance and good biocompatibility. In this work, an investigation of the in vitro cytocompatibility of a recently new developed β-type Ti–25Ta–25Nb alloy was carried out by evaluating the behavior of human osteoblasts. The metallic Ti–6Al–4V biomaterial, which is one of representative α + β type titanium alloys for biomedical applications, and Tissue Culture Polystyrene (TCPS), were also investigated as reference Ti-based material and control substrate, respectively. Both metallic surfaces were analyzed by X-ray diffraction, atomic force microscopy and X-ray photoelectron spectroscopy. The cellular response was quantified by assessments of viability, cell attachment and spreading, cell morphology, production and extracellular organization of fibronectin and cell proliferation. Polished surfaces from both materials having an equiaxed grain microstructure and nanometre scale surface roughness elicited an essentially identical osteoblast response in terms of all analyzed cellular parameters. Thus, on both surfaces the cells displayed high survival rates, good cell adhesion and spreading, a dense and randomly dispersed fibronectin matrix and increasing cell proliferation rates over the incubation time. Furhermore, the enhanced biological performance of Ti–25Ta–25Nb was highly supported by the results obtained in comparison with TCPS. These findings, together with previously shown superelastic behavior, low Young's modulus and high corrosion resistance, recommend Ti–25Ta–25Nb as good candidate for applications in bone implantology. - Graphical abstract: New beta-type Ti–25Ta–25Nb alloy (A) promotes osteoblast attachment, spreading (1) and proliferation (2) to an approximately equal extent with commonly used biomedical Ti–6Al–4V alloy (B). Highlights: ► New superelastic Ti–25Ta–25Nb alloy

  8. In vitro studies of multiwalled carbon nanotube/ultrahigh molecular weight polyethylene nanocomposites with osteoblast-like MG63 cells

    Directory of Open Access Journals (Sweden)

    J. Reis

    2010-05-01

    Full Text Available Carbon nanotubes are highly versatile materials; new applications using them are continuously being developed. Special attention is being dedicated to the possible use of multiwalled carbon nanotubes in biomaterials contacting with bone. However, carbon nanotubes are also controversial in regards to effects exerted on living organisms. Carbon nanotubes can be used to improve the tribological properties of polymer/composite materials. Ultrahigh molecular weight polyethylene (UHMWPE is a polymer widely used in orthopedic applications that imply wear and particle generation. We describe here the response of human osteoblast-like MG63 cells after 6 days of culture in contact with artificially generated particles from both UHMWPE polymer and multiwalled carbon nanotubes (MWCNT/UHMWPE nanocomposites. This novel composite has superior wear behavior, having thus the potential to reduce the number of revision hip arthroplasty surgeries required by wear failure of acetabular cups and diminish particle-induced osteolysis. The results of an in vitro study of viability and proliferation and interleukin-6 (IL-6 production suggest good cytocompatibility, similar to that of conventional UHMWPE (WST-1 assay results are reported as percentage of control ± SD: UHMWPE = 96.19 ± 7.92, MWCNT/UHMWPE = 97.92 ± 8.29%; total protein: control = 139.73 ± 10.78, UHMWPE = 137.07 ± 6.17, MWCNT/UHMWPE = 163.29 ± 11.81 µg/mL; IL-6: control = 90.93 ± 10.30, UHMWPE = 92.52 ± 11.02, MWCNT/UHMWPE = 108.99 ± 9.90 pg/mL. Standard cell culture conditions were considered as control. These results, especially the absence of significant elevation in the osteolysis inductor IL-6 values, reinforce the potential of this superior wear-resistant composite for future orthopedic applications, when compared to traditional UHMWPE.

  9. Citocompatibilidade de blendas de poli(p-dioxanona/ poli(hidroxi butirato (PPD/PHB para aplicações em engenharia de tecido cartilaginoso Cytocompatibility of poly(p-dioxanone/ poly(hydroxybutic (PPD/PHB blends to cartilage tissue engineering

    Directory of Open Access Journals (Sweden)

    Andrea R. Esposito

    2010-01-01

    Full Text Available Buscando estratégias que repercutam na melhoria da interação entre materiais poliméricos biorreabsorvíveis e o crescimento celular, o presente estudo in vitro teve como objetivo estudar a influência de blendas de PPD/PHB na adesão celular e crescimento de fibrocondrócitos obtidos a partir de cultura primária. As blendas de PPD/PHB foram preparadas pelo método de evaporação de solvente nas composições 100/0, 60/40 e 50/50 e caracterizadas por microscopia eletrônica de varredura (MEV. Observações ultra-estruturais mostraram alterações na morfologia celular, sugerindo que os fibrocondrócitos podem responder a alterações no substrato alterando seu perfil fenotípico. As análises com MTT demonstraram que as blendas não apresentaram citotoxicidade e permitiram a adesão e proliferação dos fibrocondrócitos sobre os substratos em todas as suas composições. O ensaio colorimétrico com Sirius Red evidenciou a capacidade de manutenção da síntese de matriz extracelular colágena sobre as amostras, concluindo-se que as blendas de PPD/PHB podem ser indicadas para o cultivo celular.In order of seek strategies to improve the interaction between bioreabsorbable polymer materials and cellular growth, this work aimed at evaluating in vitro the influence of PPD/PHB blends on cell adhesion and fibrochondrocytes growth. Fibrochondrocytes cells were obtained by primary extraction from enzymatic digestion methods. The PPD/PHB blends were prepared by casting with 100/0, 60/40 and 50/50 compositions, and were characterized by scanning electron microscopy (SEM. After 6, 48, 120 and 168 hours in culture, ultrastructural observations showed changes in cell morphology, suggesting that the fibrochondrocytes can respond to substrate modifications, changing their phenotypic profile. The MTT analyses showed that the blends did not present cytotoxicity and allowed fibrochondrocytes adhesion and proliferation on the membranes in all compositions

  10. T Cells

    Science.gov (United States)

    T Cells - National Multiple Sclerosis Society Skip to navigation Skip to content Menu Navigation National Multiple Sclerosis Society Sign ... Is MS? Definition of MS T Cells T Cells Share Smaller Text Larger Text Print In this ...

  11. Cell counting.

    Science.gov (United States)

    Phelan, M C; Lawler, G

    2001-05-01

    This unit presents protocols for counting cells using either a hemacytometer or electronically using a Coulter counter. Cell counting with a hemacytometer permits effective discrimination of live from dead cells using trypan blue exclusion. In addition, the procedure is less subject to errors arising from cell clumping or size heterogeneity. Counting cells is more quickly and easily performed using an electronic counter, but live-dead discrimination is unreliable. Cell populations containing large numbers of dead cells and/or cell clumps are difficult to count accurately. In addition, electronic counting requires resetting of the instrument for cell populations of different sizes; heterogeneous populations can give rise to inaccurate counts, and resting and activated cells may require counting at separate settings. In general, electronic cell counting is best performed on fresh peripheral blood cells. PMID:18770655

  12. Hierarchical micro/nanostructured titanium with balanced actions to bacterial and mammalian cells for dental implants

    Directory of Open Access Journals (Sweden)

    Zhu Y

    2015-10-01

    Full Text Available Yu Zhu,1,* Huiliang Cao,2,* Shichong Qiao,1,* Manle Wang,2,3 Yingxin Gu,1 Huiwen Luo,1 Fanhao Meng,2 Xuanyong Liu,2 Hongchang Lai1 1Department of Oral and Maxillofacial Implantology, Shanghai Key Laboratory of Stomatology, Shanghai Ninth People’s Hospital, School of Medicine, Shanghai Jiao Tong University, 2State Key Laboratory of High Performance Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics, Chinese Academy of Sciences, 3School of Materials Engineering, Shanghai University of Engineering Science, Shanghai, People’s Republic of China *These authors contributed equally to this work Abstract: A versatile strategy to endow dental implants with long-term antibacterial ability without compromising the cytocompatibility is highly desirable to combat implant-related infection. Silver nanoparticles (Ag NPs have been utilized as a highly effective and broad-spectrum antibacterial agent for surface modification of biomedical devices. However, the high mobility and subsequent hazardous effects of the particles on mammalian cells may limit its practical applications. Thus, Ag NPs were immobilized on the surface of sand-blasted, large grit, and acid-etched (SLA titanium by manipulating the atomic-scale heating effect of silver plasma immersion ion implantation. The silver plasma immersion ion implantation-treated SLA surface gave rise to both good antibacterial activity and excellent compatibility with mammalian cells. The antibacterial activity rendered by the immobilized Ag NPs was assessed using Fusobacterium nucleatum and Staphylococcus aureus, commonly suspected pathogens for peri-implant disease. The immobilized Ag NPs offered a good defense against multiple cycles of bacteria attack in both F. nucleatum and S. aureus, and the mechanism was independent of silver release. F. nucleatum showed a higher susceptibility to Ag NPs than S. aureus, which might be explained by the presence of different wall structures. Moreover, the

  13. Galvanic Cells

    Science.gov (United States)

    Young, I. G.

    1973-01-01

    Many standard physical chemistry textbooks contain ambiguities which lead to confusion about standard electrode potentials, calculating cell voltages, and writing reactions for galvanic cells. This article shows how standard electrode potentials can be used to calculate cell voltages and deduce cell reactions. (Author/RH)

  14. Stem Cells

    OpenAIRE

    Madhukar Thakur

    2009-01-01

    Objective: The objective of this presentation is to create awareness of stem cell applications in the ISORBE community and to foster a strategy of how the ISORBE community can disseminate information and promote the use of radiolabeled stem cells in biomedical applications. Methods: The continued excitement in Stem Cells, in many branches of basic and applied biomedical science, stems from the remarkable ability of stem cells to divide and develop into different types of cells in ...

  15. Cell Wall

    OpenAIRE

    Jamet, Elisabeth; Canut, Hervé; Boudart, Georges; Albenne, Cécile; Pont-Lezica, Rafael F

    2008-01-01

    This chapter covers our present knowledge of cell wall proteomics highlighting the distinctive features of cell walls and cell wall proteins in relation to problems encountered for protein extraction, separation and identification. It provides clues to design strategies for efficient cell wall proteomic studies. It gives an overview of the kinds of proteins that have yet been identified: the expected proteins vs the identified proteins. Finally, the new vision of the cell wall proteome, and t...

  16. Elastin based cell-laden injectable hydrogels with tunable gelation, mechanical and biodegradation properties.

    Science.gov (United States)

    Fathi, Ali; Mithieux, Suzanne M; Wei, Hua; Chrzanowski, Wojciech; Valtchev, Peter; Weiss, Anthony S; Dehghani, Fariba

    2014-07-01

    Injectable hydrogels made from extracellular matrix proteins such as elastin show great promise for various biomedical applications. Use of cytotoxic reagents, fixed gelling behavior, and lack of mechanical strength in these hydrogels are the main associated drawbacks. The aim of this study was to develop highly cytocompatible and injectable elastin-based hydrogels with alterable gelation characteristics, favorable mechanical properties and structural stability for load bearing applications. A thermoresponsive copolymer, poly(N-isopropylacrylamide-co-polylactide-2-hydroxyethyl methacrylate-co-oligo(ethylene glycol)monomethyl ether methacrylate, was functionalized with succinimide ester groups by incorporating N-acryloxysuccinimide monomer. These ester groups were exploited to covalently bond this polymer, denoted as PNPHO, to different proteins with primary amine groups such as α-elastin in aqueous media. The incorporation of elastin through covalent bond formation with PNPHO promotes the structural stability, mechanical properties and live cell proliferation within the structure of hydrogels. Our results demonstrated that elastin-co-PNPHO solutions were injectable through fine gauge needles and converted to hydrogels in situ at 37 °C in the absence of any crosslinking reagent. By altering PNPHO content, the gelling time of these hydrogels can be finely tuned within the range of 2-15 min to ensure compatibility with surgical requirements. In addition, these hydrogels exhibited compression moduli in the range of 40-145 kPa, which are substantially higher than those of previously developed elastin-based hydrogels. These hydrogels were highly stable in the physiological environment with the evidence of 10 wt% mass loss in 30 days of incubation in a simulated environment. This class of hydrogels is in vivo bioabsorbable due to the gradual increase of the lower critical solution temperature of the copolymer to above 37 °C due to the cleavage of polylactide from

  17. 静电纺丝纳米纤维膜作为骨骼肌组织工程支架材料的细胞相容性%Cytocompatibility of electro-spinning nano-fibrous scaffolds for skeletal muscle tissue engineering

    Institute of Scientific and Technical Information of China (English)

    梁爽; 李权; 唐休发; 冯扬; 何等旗

    2011-01-01

    -fibrous membrane were examined with MTT and scanning electron microscopy methods.RESULTS AND CONCLUSION:The absorbance value between any two groups has no statistically significant difference compared with control group (P > 0.05), while obvious statistical differences of adhesion rate lay in different groups of biomaterials (P < 0.05). The same result lies in the scanning electron microscopy image. A great quantity of myoblasts adhered to the 70% PLA + 20% silk fibroin + 10% collagen group. These myoblasts are spindle-shaped, regularly arranged, and connecting to adjacent cells. In other groups, the myoblasts are less and irregular, much more like myoblasts in recession. The electro-spinning nano-fibrous membrane has no toxicity and no bad effect on the growth of myoblasts. They adhere well on the membrane, especially on the 70% PLA + 20% silk fibroin + 1O% collagen group.

  18. Cell Motility

    CERN Document Server

    Lenz, Peter

    2008-01-01

    Cell motility is a fascinating example of cell behavior which is fundamentally important to a number of biological and pathological processes. It is based on a complex self-organized mechano-chemical machine consisting of cytoskeletal filaments and molecular motors. In general, the cytoskeleton is responsible for the movement of the entire cell and for movements within the cell. The main challenge in the field of cell motility is to develop a complete physical description on how and why cells move. For this purpose new ways of modeling the properties of biological cells have to be found. This long term goal can only be achieved if new experimental techniques are developed to extract physical information from these living systems and if theoretical models are found which bridge the gap between molecular and mesoscopic length scales. Cell Motility gives an authoritative overview of the fundamental biological facts, theoretical models, and current experimental developments in this fascinating area.

  19. A tailored three-dimensionally printable agarose-collagen blend allows encapsulation, spreading, and attachment of human umbilical artery smooth muscle cells.

    Science.gov (United States)

    Köpf, Marius; Campos, Daniela F Duarte; Blaeser, Andreas; Sen, Kshama S; Fischer, Horst

    2016-01-01

    In recent years, novel biofabrication technologies have enabled the rapid manufacture of hydrogel-cell suspensions into tissue-imitating constructs. The development of novel materials for biofabrication still remains a challenge due to a gap between contradicting requirements such as three-dimensional printability and optimal cytocompatibility. We hypothesise that blending of different hydrogels could lead to a novel material with favourable biological and printing properties. In our work, we combined agarose and type I collagen in order to develop a hydrogel blend capable of long-term cell encapsulation of human umbilical artery smooth muscle cells (HUASMCs) and 3D drop-on-demand printing. Different blends were prepared with 0.25%, 0.5%, 0.75%, and 1.5% agarose and 0.2% type I collagen. The cell morphology of HUASMCs and the printing accuracy were assessed for each agarose-collagen combination, keeping the content of collagen constant. The hydrogel blend which displayed sufficient cell spreading and printing accuracy (0.5% agarose, 0.2% type I collagen, AGR0.5COLL0.2) was then characterised based on swelling and degradation over 21 days and mechanical stiffness. The cellular response regarding cell attachment of HUASMCs embedded in the hydrogel blend was further studied using SEM, TEM, and TPLSM. Printing trials were fabricated in a drop-on-demand printing process. The swelling and degradation evaluation showed an average of 20% mass loss and less than 10% swelling. AGR0.5COLL0.2 exhibited significant increase in stiffness compared to pure agarose and type I collagen. In addition, columns of AGR0.5COLL0.2 three centimeters in height were successfully printed submerged in cooled perfluorocarbon, proving the intrinsic printability of the hydrogel blend. Ultimately, a promising novel hydrogel blend showing cell spreading and attachment as well as suitability for bioprinting was identified and could, for example, serve in the manufacture of in vitro 3D models to

  20. Solar cells

    Science.gov (United States)

    Cuquel, A.; Roussel, M.

    The physical and electronic characteristics of solar cells are discussed in terms of space applications. The principles underlying the photovoltaic effect are reviewed, including an analytic model for predicting the performance of individual cells and arrays of cells. Attention is given to the effects of electromagnetic and ionizing radiation, micrometeors, thermal and mechanical stresses, pollution and degassing encountered in space. The responses of different types of solar cells to the various performance-degrading agents are examined, with emphasis on techniques for quality assurance in the manufacture and mounting of Si cells.

  1. Synthesis, characterization, and in-vitro cytocompatibility of amorphous β-tri-calcium magnesium phosphate ceramics.

    Science.gov (United States)

    Singh, Satish S; Roy, Abhijit; Lee, Boeun; Banerjee, Ipsita; Kumta, Prashant N

    2016-10-01

    Biphasic mixtures of crystalline β-tricalcium magnesium phosphate (β-TCMP) and an amorphous calcium magnesium phosphate have been synthesized and reported to support enhanced hMSC differentiation in comparison to β-tricalcium phosphate (β-TCP) due to the release of increased amounts of bioactive ions. In the current study, completely amorphous β-TCMP has been synthesized which is capable of releasing increased amounts of Mg(2+) and PO4(3-) ions, rather than a biphasic mixture as earlier reported. The amorphous phase formed was observed to crystallize between temperatures of 400-600°C. The scaffolds prepared with amorphous β-TCMP were capable of supporting enhanced hMSC proliferation and differentiation in comparison to commercially available β-TCP. However, a similar gene expression of mature osteoblast markers, OCN and COL-1, in comparison to biphasic β-TCMP was observed. To further study the role of Mg(2+) and PO4(3-) ions in regulating hMSC osteogenic differentiation, the capability of hMSCs to mineralize in growth media supplemented with Mg(2+) and PO4(3-) ions was studied. Interestingly, 5mM PO4(3-) supported mineralization while the addition of 5mM Mg(2+) to 5mM PO4(3-) inhibited mineralization. It was therefore concluded that the release of Ca(2+) ions from β-TCMP scaffolds also plays a role in regulating osteogenic differentiation on these scaffolds and it is noted that further work is required to more accurately determine the exact role of Mg(2+) in regulating hMSC osteogenic differentiation. PMID:27287163

  2. A study of cytocompatibility and degradation of iron-based biodegradable materials.

    Science.gov (United States)

    Oriňaková, Renáta; Oriňak, Andrej; Giretová, Mária; Medvecký, L'ubomír; Kupková, Miriam; Hrubovčáková, Monika; Maskal'ová, Iveta; Macko, Ján; Kal'avský, František

    2016-02-01

    Biodegradable metallic implants are of significant importance in the replacement of bones or the repair of bone defects. Iron-phosphate-coated carbonyl iron powder (Fe/P) was prepared by the phosphating method. Moreover, Fe/P-Mn alloy was produced by sintering the Fe/P powder mixed with manganese powder. Bare carbonyl iron samples and the Fe/P and Fe/P-Mn sintered samples were evaluated for their microstructure, cytotoxicity, and hemocompatibility. The microstructure of the sintered samples was examined using an optical microscope and scanning electron microscopic analysis. Corrosion behavior was evaluated by potentiodynamic polarization in Hank's solution. The in vitro biocompatibilities were investigated by cytotoxicity and hemolysis tests. The results obtained demonstrate that the addition of Mn resulted in higher surface inhomogeneity, porosity and roughness as well as in increased cytotoxicity. The phosphate coating has a moderately negative effect on the cytotoxicity. The corrosion rates determined from Tafel diagrams were ordered in the following sequence: Fe/P-Mn, Fe, Fe/P from high to low. The hemocompatibility of experimental samples was ordered in the following sequence: Fe/P, Fe/P-Mn, Fe from high to low. All samples were found to be hemocompatible. PMID:26553881

  3. Preparation, Physical-Chemical Characterization, and Cytocompatibility of Polymeric Calcium Phosphate Cements

    Directory of Open Access Journals (Sweden)

    Rania M. Khashaba

    2011-01-01

    Full Text Available Aim. Physicochemical mechanical and in vitro biological properties of novel formulations of polymeric calcium phosphate cements (CPCs were investigated. Methods. Monocalcium phosphate, calcium oxide, and synthetic hydroxyapatite were combined with either modified polyacrylic acid, light activated polyalkenoic acid, or polymethyl vinyl ether maleic acid to obtain Types I, II, and III CPCs. Setting time, compressive and diametral strength of CPCs was compared with zinc polycarboxylate cement (control. Specimens were characterized using X-ray diffraction, scanning electron microscopy, and infrared spectroscopy. In vitro cytotoxicity of CPCs and control was assessed. Results. X-ray diffraction analysis showed hydroxyapatite, monetite, and brushite. Acid-base reaction was confirmed by the appearance of stretching peaks in IR spectra of set cements. SEM revealed rod-like crystals and platy crystals. Setting time of cements was 5–12 min. Type III showed significantly higher strength values compared to control. Type III yielded high biocompatibility. Conclusions. Type III CPCs show promise for dental applications.

  4. Cytocompatible and water-stable camelina protein films for tissue engineering.

    Science.gov (United States)

    Zhao, Yi; Jiang, Qiuran; Xu, Helan; Reddy, Narendra; Xu, Lan; Yang, Yiqi

    2014-05-01

    In this research, films with compressive strength and aqueous stability were developed from camelina protein (CP) for tissue engineering. Protein based scaffolds have poor mechanical properties and aqueous stability and generally require chemical or physical modifications to make them applicable for medical applications. However, these modifications such as crosslinking could reduce biocompatibility and/or degradability of the scaffolds. Using proteins that are inherently water-stable could avoid modifications and provide scaffolds with the desired properties. CP with a high degree of disulfide cross-linkage has the potential to provide water-stable biomaterials, but it is difficult to dissolve CP and develop scaffolds. In this study, a new method of dissolving highly cross-linked proteins that results in limited hydrolysis and preserves the protein backbone was developed to produce water-stable films from CP without any modification. Only 12 % weight loss of camelina films was observed after 7 days in phosphate buffer saline (PBS) at 37°C. NIH 3T3 fibroblasts could attach and proliferate better on camelina films than on citric acid cross-linked collagen films. Therefore, CP films have the potential to be used for tissue engineering, and this extraction-dissolution method can be used for developing biomedical materials from various water-stable plant proteins. PMID:24142899

  5. Elastin Based Cell-laden Injectable Hydrogels with Tunable Gelation, Mechanical and Biodegradation Properties

    OpenAIRE

    Fathi, Ali; Mithieux, Suzanne M.; Wei, Hua; Chrzanowski, Wojciech; Valtchev, Peter; Anthony S. Weiss; Dehghani, Fariba

    2014-01-01

    Injectable hydrogels made from extracellular matrix proteins such as elastin show great promise for various biomedical applications. Use of cytotoxic reagents, fixed gelling behavior, and lack of mechanical strength in these hydrogels are the main associated drawbacks. The aim of this study was to develop highly cytocompatible and injectable elastin-based hydrogels with alterable gelation characteristics, favorable mechanical properties and structural stability for load bearing applications. ...

  6. Model studies on heterogeneous reactions of organic components within aerosols and their influence on the condensation of water: Surface-analytical investigations on the water up-take of fly-ashes before and after exposition to fluoranthene and toluene

    International Nuclear Information System (INIS)

    The condensation of water onto four different fly ashes was investigated without any treatment, after annealing and subsequent to exposure with toluene and fluoranthene. It was intented to reveal the influence of organic aerosol components on atmospheric scavenging from particulate pollutants. Because the interaction with the ambient atmosphere is restricted to a very thin surface layer, surface analysis methods were applied to examine directly the adsorption of water or organic compounds at the surface of the fly ashes. Already some of the fly ashes as received contained organic components, which could be desorbed thermally. After their thermal removal the take-up of water improved considerably. Fluoranthene as well as the far more volatile toluene adsorbed at the particle surfaces and both caused strong impediment of the water take-up of originally hydrophilic fly ashes. The results suggest, that for any type of fly ashes the formation of a hydrophobic organic coating can be expected. This may be a result of organic flue gas components such as fluoranthene which condense downstream onto combustion aerosol particles. Or during transport of fly ash particles through organically polluted areas - e.g. with toluene in the air of busy traffic locations - organic coatings may built up. In all cases the hydrophobic coating interferes with the water take-up resulting at least in a considerable delay of the removal of pollutant particulates from the atmosphere. (orig.)

  7. Higher prevalence of sexual transmitted diseases and correlates of genital warts among heterosexual males attending sexually transmitted infection clinics (MSCs in Jiangmen, China: implication for the up-taking of STD related service.

    Directory of Open Access Journals (Sweden)

    Shujie Huang

    Full Text Available Increasing burden of STDs is one of China's major public health concerns. However, only a limited number of studies have ever investigated the prevalence of these STDs, particular for genital warts and its correlates among heterosexual males attending STD clinics in China. In order to fill this gap, we conducted a cross-sectional study among MSCs in Jiangmen, China, between the years of 2009 and 2010.The eligible participants were recruited from several STD-clinics in public hospitals. We collected demographic information and behaviors of the participants. After HIV and syphilis testing, we further checked whether the participants had genital warts and genital herpes. In addition, urine samples were collected from part of the participants for CT and NG testing.Of the 533 eligible participants, over three-fifths were aged 35 or below, nearly three quarters had no college degree, over three-fifths were residence of Jiangmen. The prevalence of HIV, syphilis, genital warts, genital herpes, CT and NG were 0.19%, 7.50%, 7.32%, 5.25%, 9.73% and 6.19%, respectively. Living with family members (versus living alone, no STD-related service in past year, experiencing STDs related symptoms in past year, and sex with FSWs in last three months were positively associated with genital warts, with adjusted ORs of 5.54 (95% CI 1.94-15.81, 2.26 (95% CI 1.08-4.74, 1.99 (95% CI 1.00-3.99 and 2.01 (95% CI 1.00-4.04, respectively.Our study indicates that the prevalence of STDs among MSCs in Jiangmen was high, which may further spread HIV among MSCs. Targeted interventions that focused on STDs related services uptake should be implemented urgently.

  8. Stem Cells

    Directory of Open Access Journals (Sweden)

    Madhukar Thakur

    2015-02-01

    Full Text Available Objective: The objective of this presentation is to create awareness of stem cell applications in the ISORBE community and to foster a strategy of how the ISORBE community can disseminate information and promote the use of radiolabeled stem cells in biomedical applications. Methods: The continued excitement in Stem Cells, in many branches of basic and applied biomedical science, stems from the remarkable ability of stem cells to divide and develop into different types of cells in the body. Often called as Magic Seeds, stem cells are produced in bone marrow and circulate in blood, albeit at a relatively low concentration. These virtues together with the ability of stem cells to grow in tissue culture have paved the way for their applications to generate new and healthy tissues and to replace diseased or injured human organs. Although possibilities of stem cell applications are many, much remains yet to be understood of these remarkable magic seeds. Conclusion: This presentation shall briefly cover the origin of stem cells, the pros and cons of their growth and division, their potential application, and shall outline some examples of the contributions of radiolabeled stem cells, in this rapidly growing branch of biomedical science

  9. Glucose-induced Ca2 + signals in rat pancreatic β cells

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Using microfluorometry to assay intracellular Ca2+ , the influences of varied factors on glucose induced Ca22+ signals, such as glucose-induced initial decline phase (GIDP), Ca2+ oscillation, and Ca2+ release from internal stores, were investigated in single rat pancreatic β cells. Glucose was able to evoke GIDP even at non-stimulus concentration (5 mol/L), which is insufficient to induce Ca2+ spikes. GIDP was dependent on neither membrane depo larization nor extraeellular Ca2+ . However, GIDP was inhibited by thapsigargin, indicating a dependence on Ca2+ up take by Ca22+ stores. The glucose-induced calcium oscillation was inhibited when external Ca2+ was removed. However, thapsigargin could not block the Ca2+ oscillation. These results suggest that maintenance of Ca22+ oscillation requires ex tracellular Ca2+ but not Ca2+ stores. Glucose was able to evoke Ca2+ signals even in the absence of external Ca2+ . The glucose-induced Ca2+ release from intracellular Ca2+ stores was blocked by TTX. However, TTX had no effect on high K--induced Ca2+ store release, suggesting that membrane depolarization can directly release Ca2+ from some internal Ca2+ stores in β cells.

  10. Types of Stem Cells

    Science.gov (United States)

    ... PDF) Download an introduction to stem cells and stem cell research. Stem Cell Glossary Stem cell terms to know. ... stem cells blog from the International Society for Stem Cell Research. Learn About Stem Cells From Lab to You ...

  11. Electrochemical Cell

    DEFF Research Database (Denmark)

    1999-01-01

    The invention relates to a rechargeable electrochemical cell comprising a negative electrode, an electrolyte and a positive electrode in which the positive electrode structure comprises a lithium cobalt manganese oxide of the composition Li¿2?Co¿y?Mn¿2-y?O¿4? where 0 cells and lithium-alloy cells....

  12. Fuel Cells

    DEFF Research Database (Denmark)

    Smith, Anders; Pedersen, Allan Schrøder

    2014-01-01

    Fuel cells have been the subject of intense research and development efforts for the past decades. Even so, the technology has not had its commercial breakthrough yet. This entry gives an overview of the technological challenges and status of fuel cells and discusses the most promising applications...... of the different types of fuel cells. Finally, their role in a future energy supply with a large share of fluctuating sustainable power sources, e.g., solar or wind, is surveyed....

  13. Cell suicide

    International Nuclear Information System (INIS)

    In the fight of the cell against the damages caused to its DNA by genotoxic agents and specially by ionizing radiations, the p53 protein plays a central part. It intervenes in the proliferation control and the differentiation but also in the keeping of genome integrity. It can direct the damages cells toward suicide, or apoptosis, to avoid the risk of tumor appearance that would be fatal to the whole organism. That is by the disordered state of cells suicide programs that the tumor cells are going to develop. The knowledge of apoptosis mechanisms, to eventually start them on demand, rises up broad hopes in the cancer therapy. (N.C.)

  14. Reprogrammed Pluripotent Stem Cells from Somatic Cells

    OpenAIRE

    Kim, Jong Soo; Choi, Hyun Woo; Choi, Sol; Do, Jeong Tae

    2011-01-01

    Pluripotent stem cells, such as embryonic stem (ES) cells, can differentiate into all cell types. So, these cells can be a biological resource for regenerative medicine. However, ES cells known as standard pluripotent cells have problem to be used for cell therapy because of ethical issue of the origin and immune response on the graft. Hence, recently reprogrammed pluripotent cells have been suggested as an alternative source for regenerative medicine. Somatic cells can acquire the ES cell-li...

  15. Water-soluble nanoconjugates of quantum dot-chitosan-antibody for in vitro detection of cancer cells based on “enzyme-free” fluoroimmunoassay

    International Nuclear Information System (INIS)

    -antibody immunoconjugate ligands. • Water-soluble CdS QDs/chitosan conjugates were prepared via one-step route. • Fluorescent nanoconjugates were effective for in vitro detection of cancer antigen. • “Enzyme-free” QD-Fluoroimmunoassay was developed for detection of cancer antigen. • Cytocompatibility of CdS-QDs/immunoconjugates was evaluated by cell viability assays

  16. Water-soluble nanoconjugates of quantum dot-chitosan-antibody for in vitro detection of cancer cells based on “enzyme-free” fluoroimmunoassay

    Energy Technology Data Exchange (ETDEWEB)

    Mansur, Herman S., E-mail: hmansur@demet.ufmg.br [Center of Nanoscience, Nanotechnology, and Innovation-CeNano" 2I, Department of Metallurgical and Materials Engineering, Federal University of Minas Gerais, UFMG, Av. Presidente Antônio Carlos, 6627, Belo Horizonte, MG 31.270-901 (Brazil); Mansur, Alexandra A.P. [Center of Nanoscience, Nanotechnology, and Innovation-CeNano" 2I, Department of Metallurgical and Materials Engineering, Federal University of Minas Gerais, UFMG, Av. Presidente Antônio Carlos, 6627, Belo Horizonte, MG 31.270-901 (Brazil); Soriano-Araújo, Amanda [Center of Nanoscience, Nanotechnology, and Innovation-CeNano" 2I, Department of Metallurgical and Materials Engineering, Federal University of Minas Gerais, UFMG, Av. Presidente Antônio Carlos, 6627, Belo Horizonte, MG 31.270-901 (Brazil); Department of Preventive Veterinary Medicine, Veterinary School, UFMG (Brazil); Lobato, Zélia I.P. [Department of Preventive Veterinary Medicine, Veterinary School, UFMG (Brazil); Carvalho, Sandhra M. de [Center of Nanoscience, Nanotechnology, and Innovation-CeNano" 2I, Department of Metallurgical and Materials Engineering, Federal University of Minas Gerais, UFMG, Av. Presidente Antônio Carlos, 6627, Belo Horizonte, MG 31.270-901 (Brazil); Department of Physiology and Biophysics, ICB, UFMG (Brazil); Leite, Maria de Fatima [Department of Physiology and Biophysics, ICB, UFMG (Brazil)

    2015-07-01

    chitosan-antibody immunoconjugate ligands. • Water-soluble CdS QDs/chitosan conjugates were prepared via one-step route. • Fluorescent nanoconjugates were effective for in vitro detection of cancer antigen. • “Enzyme-free” QD-Fluoroimmunoassay was developed for detection of cancer antigen. • Cytocompatibility of CdS-QDs/immunoconjugates was evaluated by cell viability assays.

  17. Clear Cell Basal Cell Carcinoma

    OpenAIRE

    Bo Wang; Tracey Harbert; Jennifer Olivella; Daniel Olson; Sarma, Deba P; Stephanie Ortman

    2011-01-01

    Introduction. Clear cell basal cell carcinoma (BCC) is an uncommon and unusual variant of BCC, which is characterized by a variable component of clear cells. The pathogenesis of this histological variant and its clinical significance has not been clarified. Differentiation of this uncommon variant of BCC from other clear cell tumors is important for the treatment. Case Presentation. A 65-year-old male presented with a 0.9 cm dome-shaped lesion on his upper chest. A shave biopsy revealed a der...

  18. Anatomic Mesenchymal Stem Cell-Based Engineered Cartilage Constructs for Biologic Total Joint Replacement.

    Science.gov (United States)

    Saxena, Vishal; Kim, Minwook; Keah, Niobra M; Neuwirth, Alexander L; Stoeckl, Brendan D; Bickard, Kevin; Restle, David J; Salowe, Rebecca; Wang, Margaret Ye; Steinberg, David R; Mauck, Robert L

    2016-02-01

    Cartilage has a poor healing response, and few viable options exist for repair of extensive damage. Hyaluronic acid (HA) hydrogels seeded with mesenchymal stem cells (MSCs) polymerized through UV crosslinking can generate functional tissue, but this crosslinking is not compatible with indirect rapid prototyping utilizing opaque anatomic molds. Methacrylate-modified polymers can also be chemically crosslinked in a cytocompatible manner using ammonium persulfate (APS) and N,N,N',N'-tetramethylethylenediamine (TEMED). The objectives of this study were to (1) compare APS/TEMED crosslinking with UV crosslinking in terms of functional maturation of MSC-seeded HA hydrogels; (2) generate an anatomic mold of a complex joint surface through rapid prototyping; and (3) grow anatomic MSC-seeded HA hydrogel constructs using this alternative crosslinking method. Juvenile bovine MSCs were suspended in methacrylated HA (MeHA) and crosslinked either through UV polymerization or chemically with APS/TEMED to generate cylindrical constructs. Minipig porcine femoral heads were imaged using microCT, and anatomic negative molds were generated by three-dimensional printing using fused deposition modeling. Molded HA constructs were produced using the APS/TEMED method. All constructs were cultured for up to 12 weeks in a chemically defined medium supplemented with TGF-β3 and characterized by mechanical testing, biochemical assays, and histologic analysis. Both UV- and APS/TEMED-polymerized constructs showed increasing mechanical properties and robust proteoglycan and collagen deposition over time. At 12 weeks, APS/TEMED-polymerized constructs had higher equilibrium and dynamic moduli than UV-polymerized constructs, with no differences in proteoglycan or collagen content. Molded HA constructs retained their hemispherical shape in culture and demonstrated increasing mechanical properties and proteoglycan and collagen deposition, especially at the edges compared to the center of these larger

  19. Fuel cells

    Directory of Open Access Journals (Sweden)

    D. N. Srivastava

    1962-05-01

    Full Text Available The current state of development of fuel cells as potential power sources is reviewed. Applications in special fields with particular reference to military requirements are pointed out.

  20. Dry cell battery poisoning

    Science.gov (United States)

    Batteries - dry cell ... Acidic dry cell batteries contain: Manganese dioxide Ammonium chloride Alkaline dry cell batteries contain: Sodium hydroxide Potassium hydroxide Lithium dioxide dry cell batteries ...

  1. Cell sorting by deterministic cell rolling

    OpenAIRE

    Choi, Sungyoung; Karp, Jeffrey M.; Karnik, Rohit

    2011-01-01

    This communication presents the concept of “deterministic cell rolling”, which leverages transient cell-surface molecular interactions that mediate cell rolling to sort cells with high purity and efficiency in a single step.

  2. Solar cells

    Science.gov (United States)

    Treble, F. C.

    1980-11-01

    The history, state of the art, and future prospects of solar cells are reviewed. Solar cells are already competitive in a wide range of low-power applications, and during the 1980's they are expected to become cheaper to run than diesel or gasoline generators, the present mainstay of isolated communities. At this stage they will become attractive for water pumping, irrigation, and rural electrification, particularly in developing countries. With further cost reduction, they may be used to augment grid supplies in domestic, commercial, institutional, and industrial premises. Cost reduction to the stage where photovoltaics becomes economic for large-scale power generation in central stations depends on a technological breakthrough in the development of thin-film cells. DOE aims to reach this goal by 1990, so that by the end of the century about 20% of the estimated annual additions to their electrical generating capacity will be photovoltaic.

  3. Cell Libraries

    Science.gov (United States)

    1994-01-01

    A NASA contract led to the development of faster and more energy efficient semiconductor materials for digital integrated circuits. Gallium arsenide (GaAs) conducts electrons 4-6 times faster than silicon and uses less power at frequencies above 100-150 megahertz. However, the material is expensive, brittle, fragile and has lacked computer automated engineering tools to solve this problem. Systems & Processes Engineering Corporation (SPEC) developed a series of GaAs cell libraries for cell layout, design rule checking, logic synthesis, placement and routing, simulation and chip assembly. The system is marketed by Compare Design Automation.

  4. Solar cells

    International Nuclear Information System (INIS)

    A method of producing solar cells is described which consists of producing a substantially monocrystalline tubular body of silicon or other suitable semiconductor material, treating this body to form an annular rectifying junction and then cutting it longitudinally to form a number of nearly flat ribbons from which the solar cells are fabricated. The P=N rectifying junction produced by the formation of silicon dioxide on the layers at the inner and outer surfaces of the body can be formed by ion-implantation or diffusion. (U.K.)

  5. Stem Cells

    DEFF Research Database (Denmark)

    Sommerlund, Julie

    2004-01-01

    In his influential essay on markets, An essay on framing and overflowing (1998), Michel Callon writes that `the growing complexity of industrialized societies [is] due in large part to the movements of the technosciences, which are causing connections and interdependencies to proliferate'. This p...... and tantalizing than stem cells, in research, in medicine, or as products.......'. This paper is about tech-noscience, and about the proliferation of connections and interdependencies created by it.More specifically, the paper is about stem cells. Biotechnology in general has the power to capture the imagination. Within the field of biotechnology nothing seems more provocative...

  6. Sickle Cell Anemia

    Science.gov (United States)

    Sickle cell anemia is a disease in which your body produces abnormally shaped red blood cells. The cells are shaped like ... normal, round red blood cells. This leads to anemia. The sickle cells also get stuck in blood ...

  7. Stem Cell Basics

    Science.gov (United States)

    ... Information Stem Cell Basics Stem Cell Basics: Introduction Stem Cell Information General Information Clinical Trials Funding Information Current Research Policy Glossary Site Map Stem Cell Basics Introduction: What are stem cells, and why ...

  8. Stem Cell Information: Glossary

    Science.gov (United States)

    ... Neurons Oligodendrocyte Parthenogenesis Passage Pluripotent Polar body Preimplantation Proliferation Regenerative medicine Reproductive cloning Signals Somatic cell Somatic cell nuclear transfer (SCNT) Somatic (adult) stem cell Stem cells Stromal cells Subculturing Surface markers ...

  9. Learn About Stem Cells

    Science.gov (United States)

    ... PDF) Download an introduction to stem cells and stem cell research. Stem Cell Glossary Stem cell terms to know. ... ISSCR Get Involved Media © 2015 International Society for Stem Cell Research Terms of Use Disclaimer Privacy Policy

  10. Photovoltaic cell

    Science.gov (United States)

    Gordon, Roy G.; Kurtz, Sarah

    1984-11-27

    In a photovoltaic cell structure containing a visibly transparent, electrically conductive first layer of metal oxide, and a light-absorbing semiconductive photovoltaic second layer, the improvement comprising a thin layer of transition metal nitride, carbide or boride interposed between said first and second layers.

  11. Fuel cells:

    DEFF Research Database (Denmark)

    Sørensen, Bent

    2013-01-01

    A brief overview of the progress in fuel cell applications and basic technology development is presented, as a backdrop for discussing readiness for penetration into the marketplace as a solution to problems of depletion, safety, climate or environmental impact from currently used fossil and...... nuclear fuel-based energy technologies....

  12. Cell Docking, Movement and Cell-Cell Interactions of Heterogeneous Cell Suspensions in a Cell Manipulation Microdevice

    OpenAIRE

    Long-Sun Huang; Yu-Hung Wang; Yu-Wei Chung; Fei-Lung Lai; Shiaw-Min Hwang

    2011-01-01

    This study demonstrates a novel cell manipulation microdevice for cell docking, culturing, cell-cell contact and interaction by microfluidic manipulation of heterogeneous cell suspensions. Heterogeneous cell suspensions include disparate blood cells of natural killer cells and leukemia cancer cells for immune cell transplantation therapy. However, NK cell alloreactivity from different healthy donors present various recovery response levels. Little is still known about the interactions and cyt...

  13. Reprogrammed pluripotent stem cells from somatic cells.

    Science.gov (United States)

    Kim, Jong Soo; Choi, Hyun Woo; Choi, Sol; Do, Jeong Tae

    2011-06-01

    Pluripotent stem cells, such as embryonic stem (ES) cells, can differentiate into all cell types. So, these cells can be a biological resource for regenerative medicine. However, ES cells known as standard pluripotent cells have problem to be used for cell therapy because of ethical issue of the origin and immune response on the graft. Hence, recently reprogrammed pluripotent cells have been suggested as an alternative source for regenerative medicine. Somatic cells can acquire the ES cell-like pluripotency by transferring somatic cell nuclei into oocytes, by cell fusion with pluripotent cells. Retroviral-mediated introduction of four factors, Oct4, Sox2, Klf4 and c-Myc can successfully reprogram somatic cells into ES cell-like pluripotent stem cells, known as induced pluripotent stem (iPS) cells. These cells closely resemble ES cells in gene expression pattern, cell biologic and phenotypic characteristics. However, to reach the eventual goal of clinical application, it is necessary to overcome the major drawbacks such as low reprogramming efficiency and genomic alterations due to viral integration. In this review, we discuss the current reprogramming techniques and mechanisms of nuclear reprogramming induced by transcription factor transduction. PMID:24298328

  14. Red blood cells, sickle cell (image)

    Science.gov (United States)

    Sickle cell anemia is an inherited blood disease in which the red blood cells produce abnormal pigment (hemoglobin). ... abnormal hemoglobin causes deformity of the red blood cells into crescent or sickle-shapes, as seen in this photomicrograph.

  15. Stem cell glycolipids.

    Science.gov (United States)

    Yanagisawa, Makoto

    2011-09-01

    Glycolipids are compounds containing one or more monosaccharide residues bound by a glycosidic linkage to a hydrophobic moiety. Because of their expression patterns and the intracellular localization patterns, glycolipids, including stage-specific embryonic antigens (SSEA-3, SSEA-4, and possibly SSEA-1) and gangliosides (e.g., GD3, GD2, and A2B5 antigens), have been used as marker molecules of stem cells. In this review, I will introduce glycolipids expressed in pluripotent stem cells (embryonic stem cells, induced pluripotent stem cells, very small embryonic-like stem cells, amniotic stem cells, and multilineage-differentiating stress enduring cells), multipotent stem cells (neural stem cells, mesenchymal stem cells, fetal liver multipotent progenitor cells, and hematopoietic stem cells), and cancer stem cells (brain cancer stem cells and breast cancer stem cells), and discuss their availability as biomarkers for identifying and isolating stem cells. PMID:21161592

  16. Murine Mueller cells are progenitor cells for neuronal cells and fibrous tissue cells

    International Nuclear Information System (INIS)

    Mammalian Mueller cells have been reported to possess retinal progenitor cell properties and generate new neurons after injury. This study investigates murine Mueller cells under in vitro conditions for their capability of dedifferentiation into retinal progenitor cells. Mueller cells were isolated from mouse retina, and proliferating cells were expanded in serum-containing medium. For dedifferentiation, the cultured cells were transferred to serum-replacement medium (SRM) at different points in time after their isolation. Interestingly, early cell passages produced fibrous tissue in which extracellular matrix proteins and connective tissue markers were differentially expressed. In contrast, aged Mueller cell cultures formed neurospheres in SRM that are characteristic for neuronal progenitor cells. These neurospheres differentiated into neuron-like cells after cultivation on laminin/ornithine cell culture substrate. Here, we report for the first time that murine Mueller cells can be progenitors for both, fibrous tissue cells and neuronal cells, depending on the age of the cell culture

  17. Sickle Cell Anemia

    Science.gov (United States)

    Sickle cell anemia is a disease in which your body produces abnormally shaped red blood cells. The cells are ... pain and organ damage. A genetic problem causes sickle cell anemia. People with the disease are born with two ...

  18. Sickle cell test

    Science.gov (United States)

    The sickle cell test looks for the abnormal hemoglobin in the blood that causes the disease sickle cell anemia . ... if a person has abnormal hemoglobin that causes sickle cell disease and sickle cell trait. Hemoglobin is a ...

  19. What are Stem Cells?

    OpenAIRE

    Ahmadshah Farhat; Ashraf Mohammadzadeh; Rezaie, M.

    2014-01-01

      Stem cells are undifferentiated self regenerating multi potential cells. There are three types of stem cells categories by the ability to form after cells and correlated with the body’s development process. Totipotent: these stem cells can form an entire organism such as fertilized egg. Ploripotent: ploripotent cells are those that can form any cell in the body but cannot form an entire organism such as developing embryo’s totipotent cells become ploripotent  Multipotent: Multi potent stem ...

  20. Pluripotent stem cell lines

    OpenAIRE

    Yu, Junying; Thomson, James A.

    2008-01-01

    The derivation of human embryonic stem cells 10 years ago ignited an explosion of public interest in stem cells, yet this achievement depended on prior decades of research on mouse embryonic carcinoma cells and embryonic stem cells. In turn, the recent derivation of mouse and human induced pluripotent stem cells depended on the prior studies on mouse and human embryonic stem cells. Both human embryonic stem cells and induced pluripotent stem cells can self-renew indefinitely in vitro while ma...

  1. DNA-cell conjugates

    Energy Technology Data Exchange (ETDEWEB)

    Hsiao, Shih-Chia; Francis, Matthew B.; Bertozzi, Carolyn; Mathies, Richard; Chandra, Ravi; Douglas, Erik; Twite, Amy; Toriello, Nicholas; Onoe, Hiroaki

    2016-05-03

    The present invention provides conjugates of DNA and cells by linking the DNA to a native functional group on the cell surface. The cells can be without cell walls or can have cell walls. The modified cells can be linked to a substrate surface and used in assay or bioreactors.

  2. Molecular Mechanisms of Cell-cell Recognition

    Institute of Scientific and Technical Information of China (English)

    WANG Jia-Huai

    2004-01-01

    Cell-cell recognition is the key for multicellular organisms to survive. This recognition critically depends on protein-protein interactions from opposing cell surfaces. Recent structural investigations reveal unique features of these cell surface receptors and how they interact. These interactions are specific, but usually relatively weak, with more hydrophilic forces involved in binding. The receptors appear to have specialized ways to present their key interacting elements for ligand-binding from the cell surface. Cell-cell contacts are multivalent. A large group of cell surface molecules are engaged in interactions. Characteristic weak interactions make possible for each individual molecule pair within the group to constantly associate-dissociate-reassociate, such that the cell-cell recognition becomes a dynamic process. The immunological synapse is a good example for immune receptors to be orchestrated in performing immunological function in a collective fashion.

  3. Integrated circuit cell library

    Science.gov (United States)

    Whitaker, Sterling R. (Inventor); Miles, Lowell H. (Inventor)

    2005-01-01

    According to the invention, an ASIC cell library for use in creation of custom integrated circuits is disclosed. The ASIC cell library includes some first cells and some second cells. Each of the second cells includes two or more kernel cells. The ASIC cell library is at least 5% comprised of second cells. In various embodiments, the ASIC cell library could be 10% or more, 20% or more, 30% or more, 40% or more, 50% or more, 60% or more, 70% or more, 80% or more, 90% or more, or 95% or more comprised of second cells.

  4. Modeling cell-in-cell structure into its biological significance

    OpenAIRE

    He, M-f; Wang, S.; Y Wang; Wang, X-n

    2013-01-01

    Although cell-in-cell structure was noted 100 years ago, the molecular mechanisms of ‘entering' and the destination of cell-in-cell remain largely unclear. It takes place among the same type of cells (homotypic cell-in-cell) or different types of cells (heterotypic cell-in-cell). Cell-in-cell formation affects both effector cells and their host cells in multiple aspects, while cell-in-cell death is under more intensive investigation. Given that cell-in-cell has an important role in maintainin...

  5. nduced pluripotent stem cells and cell therapy

    Directory of Open Access Journals (Sweden)

    Banu İskender

    2013-12-01

    Full Text Available Human embryonic stem cells are derived from the inner cell mass of a blastocyst-stage embryo. They hold a huge promise for cell therapy with their self-renewing ability and pluripotency, which is known as the potential to differentiate into all cell types originating from three embryonic germ layers. However, their unique pluripotent feature could not be utilised for therapeutic purposes due to the ethical and legal problems during derivation. Recently, it was shown that the cells from adult tissues could be reverted into embryonic state, thereby restoring their pluripotent feature. This has strenghtened the possiblity of directed differentition of the reprogrammed somatic cells into the desired cell types in vitro and their use in regenerative medicine. Although these cells were termed as induced pluripotent cells, the mechanism of pluripotency has yet to be understood. Still, induced pluripotent stem cell technology is considered to be significant by proposing novel approaches in disease modelling, drug screening and cell therapy. Besides their self-renewing ability and their potential to differentiate into all cell types in a human body, they arouse a great interest in scientific world by being far from the ethical concerns regarding their embryonic counterparts and their unique feature of being patient-specific in prospective cell therapies. In this review, induced pluripotent stem cell technology and its role in cell-based therapies from past to present will be discussed. J Clin Exp Invest 2013; 4 (4: 550-561

  6. Monitoring cell growth.

    Science.gov (United States)

    Strober, W

    2001-05-01

    This appendix provides two protocols for monitoring cell growth. Counting cells using a hemacytometer is tedious but it allows one to effectively distinguish live cells from dead cells (using Trypan Blue exclusion). In addition, this procedure is less subject to errors due to cell clumping or heterogeneity of cell size. The use of an electronic cell counter is quicker and easier than counting cells using a hemacytometer. However, an electronic cell counter as currently constructed does not distinguish live from dead cells in a reliable fashion and is subject to error due to the presence of cell clumps. Overall, the electronic cell counter is best reserved for repetitive and rapid counting of fresh peripheral blood cells and should be used with caution when counting cell populations derived from tissues. PMID:18432653

  7. Chromophobe Renal Cell Carcinoma

    OpenAIRE

    Jyotsna Vijaykumar Wader; Sujata S Kumbhar; Huddedar AD; Wasim GM Khatib

    2013-01-01

    Renal cell carcinoma is the most common neoplasm of the kidney comprised of different histological variants. Chromophobe renal cell carcinoma (ChRCC) is a rare subtype of renal cell carcinoma (RCC) mainly diagnosed in the sixth decade of life. It is important to identify this entity because it has significantly better prognosis than the clear cell (conventional) and papillary renal cell carcinomas. The chromophobe renal cell carcinoma should be differentiated from oncocytoma and clear cell ca...

  8. Automated Cell-Cutting for Cell Cloning

    Science.gov (United States)

    Ichikawa, Akihiko; Tanikawa, Tamio; Matsukawa, Kazutsugu; Takahashi, Seiya; Ohba, Kohtaro

    We develop an automated cell-cutting technique for cell cloning. Animal cells softened by the cytochalasin treatment are injected into a microfluidic chip. The microfluidic chip contains two orthogonal channels: one microchannel is wide, used to transport cells, and generates the cutting flow; the other is thin and used for aspiration, fixing, and stretching of the cell. The injected cell is aspirated and stretched in the thin microchannel. Simultaneously, the volumes of the cell before and after aspiration are calculated; the volumes are used to calculate the fluid flow required to aspirate half the volume of the cell into the thin microchannel. Finally, we apply a high-speed flow in the orthogonal microchannel to bisect the cell. This paper reports the cutting process, the cutting system, and the results of the experiment.

  9. Mantle Cell Lymphoma

    Science.gov (United States)

    Getting the Facts Mantle Cell Lymphoma Overview Lymphoma is the most common blood cancer. The two main forms of lymphoma are Hodgkin lymphoma ... lymphocytes (B-cells) and T-lymphocytes (T-cells). Mantle cell lymphoma (MCL) is a rare, B-cell ...

  10. Host cell reactivation in mammalian cells

    International Nuclear Information System (INIS)

    The survival of UV-irradiated herpes simplex virus was determined in cultured Potoroo (a marsupial) and human cells under lighting conditions which promoted photereactivation. Photoreactivation was readily demonstrated for herpes virus in two lines of Potoroo cells with dose reduction factors of 0.7 to 0.8 for ovary cells and 0.5 to 0.7 for kidney cells. Light from Blacklite (near UV) lamps was more effective than from Daylight (mostly visible) lamps, suggesting that near UV radiation was more effecient for photoreactivation in Potoroo cells. The quantitative and qualitative aspects of this photoreactivation were similar to those reported for a similar virus infecting chick embryo cells. UV-survival curves of herpes virus in Potoroo cells indicated a high level of 'dark' host cell reactivation. No photoreactivation was found for UV-irradiated vaccinia virus in Potoroo cells. A similar photoreactivation study was done using special control lighting (lambda>600 nm) and human cells with normal repair and with cells deficient in excision repair (XP). No photoreactivation was found for UV-irradiated herpes virus in either human cell with either Blacklite or Daylight lamps as the sources of photoreactivating light. This result contrasts with a report of photoreactivation for a herpes virus in the same XP cells using incandescent lamps. (author)

  11. Cell culture purity issues and DFAT cells

    International Nuclear Information System (INIS)

    Highlights: •DFAT cells are progeny cells derived from dedifferentiated mature adipocytes. •Common problems in this research is potential cell contamination of initial cultures. •The initial cell culture purity is crucial in DFAT cell research field. -- Abstract: Dedifferentiation of mature adipocytes, in vitro, has been pursued/documented for over forty years. The subsequent progeny cells are named dedifferentiated adipocyte-derived progeny cells (DFAT cells). DFAT cells are proliferative and likely to possess mutilineage potential. As a consequence, DFAT cells and their progeny/daughter cells may be useful as a potential tool for various aspects of tissue engineering and as potential vectors for the alleviation of several disease states. Publications in this area have been increasing annually, but the purity of the initial culture of mature adipocytes has seldom been documented. Consequently, it is not always clear whether DFAT cells are derived from dedifferentiated mature (lipid filled) adipocytes or from contaminating cells that reside in an impure culture

  12. CELL RESEARCH

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    REVIEWSInducible resistance to Fas-mediated apoptosis in B cells…………………………………ROTHSTEIN Thomas L (245)Executionary pathway for apoptosis: lessons from mutant mice………………………………………WOO Minna, Razqallah Hakem, Tak W Mak (267)The SHP-2 tyrosine phosphatase: Signaling mechanisms and biological functions…………………………………QU Cheng Kui (279)REGULAR ARTICLESTemperature dependent expression of cdc2 and cyclin B1 in spermatogenic cells during spermatogenesis…………………………KONG Wei Hua, Zheng GU, Jining LU, Jiake TSO (289)Transgenic mice overexpressing γ-aminobutyric acid transporter subtype I develop obesity…………………………………MA Ying Hua, Jia Hua HU, Xiao Gang ZHOU, Ruo Wang ZENG, Zhen Tong MEI, Jian FEI, Li He GUO (303)Genetic aberration in primary hepatocellular carcinoma: correlation between p53 gene mutation and loss-of-heterozygosity on chromosome 16q21-q23 and 9p21-p23………………………………………WANG Gang, Chang Hui HUANG, Yan ZHAO, Ling CAI, Ying WANG, Shi Jin XIU, Zheng Wen JIANG, Shuang YANG, Xin Tai ZHAO, Wei HUANG, Jian Ren GU (311)Identification and genetic mapping of four novel genes that regulate leaf deve- lopment in Arabidopsis………………………………………………SUN Yue, Wei ZHANG, Feng Ling LI, Ying Li GUO, Tian Lei LIU, Hai HUANG (325)NOTICE FOR CONTRIBUTORS…………………………………(337)CONTENTS of Vol. 10, 2000…………………………………………………(338)

  13. Cell Membrane Softening in Cancer Cells

    Science.gov (United States)

    Schmidt, Sebastian; Händel, Chris; Käs, Josef

    Biomechanical properties are useful characteristics and regulators of the cell's state. Current research connects mechanical properties of the cytoskeleton to many cellular processes but does not investigate the biomechanics of the plasma membrane. We evaluated thermal fluctuations of giant plasma membrane vesicles, directly derived from the plasma membranes of primary breast and cervical cells and observed a lowered rigidity in the plasma membrane of malignant cells compared to non-malignant cells. To investigate the specific role of membrane rigidity changes, we treated two cell lines with the Acetyl-CoA carboxylase inhibitor Soraphen A. It changed the lipidome of cells and drastically increased membrane stiffness by up regulating short chained membrane lipids. These altered cells had a decreased motility in Boyden chamber assays. Our results indicate that the thermal fluctuations of the membrane, which are much smaller than the fluctuations driven by the cytoskeleton, can be modulated by the cell and have an impact on adhesion and motility.

  14. Mammary stem cells have myoepithelial cell properties.

    Science.gov (United States)

    Prater, Michael D; Petit, Valérie; Alasdair Russell, I; Giraddi, Rajshekhar R; Shehata, Mona; Menon, Suraj; Schulte, Reiner; Kalajzic, Ivo; Rath, Nicola; Olson, Michael F; Metzger, Daniel; Faraldo, Marisa M; Deugnier, Marie-Ange; Glukhova, Marina A; Stingl, John

    2014-10-01

    Contractile myoepithelial cells dominate the basal layer of the mammary epithelium and are considered to be differentiated cells. However, we observe that up to 54% of single basal cells can form colonies when seeded into adherent culture in the presence of agents that disrupt actin-myosin interactions, and on average, 65% of the single-cell-derived basal colonies can repopulate a mammary gland when transplanted in vivo. This indicates that a high proportion of basal myoepithelial cells can give rise to a mammary repopulating unit (MRU). We demonstrate that myoepithelial cells, flow-sorted using two independent myoepithelial-specific reporter strategies, have MRU capacity. Using an inducible lineage-tracing approach we follow the progeny of myoepithelial cells that express α-smooth muscle actin and show that they function as long-lived lineage-restricted stem cells in the virgin state and during pregnancy. PMID:25173976

  15. Galvanic cells: setting up the Daniell cell.

    OpenAIRE

    2008-01-01

    With the reagents (0.05M copper nitrate solution, 0.05M zinc nitrate solution) and material (glassware, potentiometer, electric wire) availabe in the laboratory, the user must set up the Daniell cell. Different configurations can be possible if the half cells are filled with either electrolyte solution. The cell connections to the measuring device can also be changed. In all instances, an explanation of the set up cell is obtained as well as of the measured potential difference.

  16. Mammary stem cells have myoepithelial cell properties

    OpenAIRE

    Prater, Michael D.; Petit, Val?rie; Russell, I Alasdair; Giraddi, Rajshekhar; Shehata, Mona; Menon, Suraj; Schulte, Reiner; Kalajzic, Ivo; Rath, Nicola; Olson, Michael F.; Metzger, Daniel; Faraldo, Marisa M.; Deugnier, Marie-Ange; Glukhova, Marina A.; Stingl, John

    2014-01-01

    Contractile myoepithelial cells dominate the basal layer of the mammary epithelium and are considered to be differentiated cells. However, we observe that up to 54% of single basal cells can form colonies when seeded into adherent culture in the presence of agents that disrupt acin-myosin interactions, and on average, 65% of the single-cell-derived basal colonies can repopulate a mammary gland when transplanted in vivo. This indicates that a high proportion of basal myoepi...

  17. Lung cancer - small cell

    Science.gov (United States)

    Cancer - lung - small cell; Small cell lung cancer; SCLC ... About 15% of all lung cancer cases are SCLC. Small cell lung cancer is slightly more common in men than women. Almost all cases of SCLC ...

  18. GSPEL - Fuel Cell Laboratory

    Data.gov (United States)

    Federal Laboratory Consortium — The Fuel Cell Lab (FCL) Provides testing for technology readiness of fuel cell systems The FCL investigates, tests and verifies the performance of fuel-cell systems...

  19. Squamous cell skin cancer

    Science.gov (United States)

    ... earliest form of squamous cell cancer is called Bowen disease (or squamous cell carcinoma in situ). This type ... cancer; Squamous cell carcinoma of the skin Images Bowen's disease on the hand Keratoacanthoma Keratoacanthoma Skin cancer, squamous ...

  20. Lung cancer - small cell

    Science.gov (United States)

    Cancer - lung - small cell; Small cell lung cancer; SCLC ... About 15% of all lung cancer cases are SCLC. Small cell lung cancer is slightly more common in men than women. Almost all cases of SCLC are ...

  1. Cell sheet engineering

    Directory of Open Access Journals (Sweden)

    Masayuki Yamato

    2004-05-01

    Full Text Available We have developed ‘cell sheet engineering’ in order to avoid the limitations of tissue reconstruction using biodegradable scaffolds or single cell suspension injection. Our concept is tissue reconstruction, not from single cells, but from cell sheets. Cell sheets are prepared using temperature-responsive culture dishes. Temperature-responsive polymers are covalently grafted onto the dishes, allowing various types of cells to adhere and proliferate at 37°C. The cells spontaneously detach when the temperature is reduced below 32°C without the need for proteolytic enzymes. The confluent cells are noninvasively harvested as single, contiguous cell sheets with intact cell-cell junctions and deposited extracellular matrix (ECM. We have used these harvested cell sheets for various tissue reconstructions, including ocular surfaces, periodontal ligaments, cardiac patches, and bladder augmentation.

  2. Sickle Cell Disease (SCD)

    Science.gov (United States)

    ... disease (SCD) Email this page Print this page Sickle cell disease (SCD) Sickle cell disease (SCD) is a disease of the hemoglobin. ... and form a sickle or a cresent. Tweet Sickle cell disease (SCD) Symptoms of SCD How transplant can ...

  3. Sickle Cell Disease

    Science.gov (United States)

    ... in Sickle Cell Disease New supplement from the American Journal of Preventive Medicine describes the state of sickle cell disease related care in the United States. Read Supplement » ... are affected by sickle cell disease. More WEBINAR ...

  4. Sickle Cell Disease

    Science.gov (United States)

    ... from the NHLBI on Twitter. What Is Sickle Cell Disease? Español The term sickle cell disease (SCD) ... common forms of SCD. Some Forms of Sickle Cell Disease Hemoglobin SS Hemoglobin SC Hemoglobin Sβ 0 thalassemia ...

  5. Basal Cell Carcinoma (BCC)

    Science.gov (United States)

    ... epithelioma, is the most common form of skin cancer. Basal cell carcinoma usually occurs on sun-damaged skin, especially ... other health issues. Infiltrating or morpheaform basal cell carcinomas: Infiltrating basal cell carcinomas can be more aggressive and locally destructive ...

  6. Snail modulates cell metabolism in MDCK cells

    International Nuclear Information System (INIS)

    Highlights: ► MDCK/snail cells were more sensitive to glucose deprivation than MDCK/neo cells. ► MDCK/snail cells had decreased oxidative phosphorylation, O2 consumption and ATP content. ► TCA cycle enzyme activity, but not expression, was lower in MDCK/snail cells. ► MDCK/snail cells showed reduced PDH activity and increased PDK1 expression. ► MDCK/snail cells showed reduced expression of GLS2 and ACLY. -- Abstract: Snail, a repressor of E-cadherin gene transcription, induces epithelial-to-mesenchymal transition and is involved in tumor progression. Snail also mediates resistance to cell death induced by serum depletion. By contrast, we observed that snail-expressing MDCK (MDCK/snail) cells undergo cell death at a higher rate than control (MDCK/neo) cells in low-glucose medium. Therefore, we investigated whether snail expression influences cell metabolism in MDCK cells. Although gylcolysis was not affected in MDCK/snail cells, they did exhibit reduced pyruvate dehydrogenase (PDH) activity, which controls pyruvate entry into the tricarboxylic acid (TCA) cycle. Indeed, the activity of multiple enzymes involved in the TCA cycle was decreased in MDCK/snail cells, including that of mitochondrial NADP+-dependent isocitrate dehydrogenase (IDH2), succinate dehydrogenase (SDH), and electron transport Complex II and Complex IV. Consequently, lower ATP content, lower oxygen consumption and increased survival under hypoxic conditions was also observed in MDCK/snail cells compared to MDCK/neo cells. In addition, the expression and promoter activity of pyruvate dehydrogenase kinase 1 (PDK1), which phosphorylates and inhibits the activity of PDH, was increased in MDCK/snail cells, while expression levels of glutaminase 2 (GLS2) and ATP-citrate lyase (ACLY), which are involved in glutaminolysis and fatty acid synthesis, were decreased in MDCK/snail cells. These results suggest that snail modulates cell metabolism by altering the expression and activity of key enzymes

  7. Snail modulates cell metabolism in MDCK cells

    Energy Technology Data Exchange (ETDEWEB)

    Haraguchi, Misako, E-mail: haraguci@m3.kufm.kagoshima-u.ac.jp [Department of Biochemistry and Molecular Biology, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima 890-8544 (Japan); Indo, Hiroko P. [Department of Maxillofacial Radiology, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima 890-8544 (Japan); Iwasaki, Yasumasa [Health Care Center, Kochi University, Kochi 780-8520 (Japan); Iwashita, Yoichiro [Department of Maxillofacial Radiology, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima 890-8544 (Japan); Fukushige, Tomoko [Department of Dermatology, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima 890-8544 (Japan); Majima, Hideyuki J. [Department of Maxillofacial Radiology, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima 890-8544 (Japan); Izumo, Kimiko; Horiuchi, Masahisa [Department of Environmental Medicine, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima 890-8544 (Japan); Kanekura, Takuro [Department of Dermatology, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima 890-8544 (Japan); Furukawa, Tatsuhiko [Department of Molecular Oncology, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima 890-8544 (Japan); Ozawa, Masayuki [Department of Biochemistry and Molecular Biology, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima 890-8544 (Japan)

    2013-03-22

    Highlights: ► MDCK/snail cells were more sensitive to glucose deprivation than MDCK/neo cells. ► MDCK/snail cells had decreased oxidative phosphorylation, O{sub 2} consumption and ATP content. ► TCA cycle enzyme activity, but not expression, was lower in MDCK/snail cells. ► MDCK/snail cells showed reduced PDH activity and increased PDK1 expression. ► MDCK/snail cells showed reduced expression of GLS2 and ACLY. -- Abstract: Snail, a repressor of E-cadherin gene transcription, induces epithelial-to-mesenchymal transition and is involved in tumor progression. Snail also mediates resistance to cell death induced by serum depletion. By contrast, we observed that snail-expressing MDCK (MDCK/snail) cells undergo cell death at a higher rate than control (MDCK/neo) cells in low-glucose medium. Therefore, we investigated whether snail expression influences cell metabolism in MDCK cells. Although gylcolysis was not affected in MDCK/snail cells, they did exhibit reduced pyruvate dehydrogenase (PDH) activity, which controls pyruvate entry into the tricarboxylic acid (TCA) cycle. Indeed, the activity of multiple enzymes involved in the TCA cycle was decreased in MDCK/snail cells, including that of mitochondrial NADP{sup +}-dependent isocitrate dehydrogenase (IDH2), succinate dehydrogenase (SDH), and electron transport Complex II and Complex IV. Consequently, lower ATP content, lower oxygen consumption and increased survival under hypoxic conditions was also observed in MDCK/snail cells compared to MDCK/neo cells. In addition, the expression and promoter activity of pyruvate dehydrogenase kinase 1 (PDK1), which phosphorylates and inhibits the activity of PDH, was increased in MDCK/snail cells, while expression levels of glutaminase 2 (GLS2) and ATP-citrate lyase (ACLY), which are involved in glutaminolysis and fatty acid synthesis, were decreased in MDCK/snail cells. These results suggest that snail modulates cell metabolism by altering the expression and activity of

  8. Artificial Stem Cell Niches

    OpenAIRE

    Lutolf, Matthias P.; Blau, Helen M.

    2009-01-01

    Stem cells are characterized by their dual ability to reproduce themselves (self-renew) and specialize (differentiate), yielding a plethora of daughter cells that maintain and regenerate tissues. In contrast to their embryonic counterparts, adult stem cells retain their unique functions only if they are in intimate contact with an instructive microenvironment, termed stem cell niche. In these niches, stem cells integrate a complex array of molecular signals that, in concert with induced cell-...

  9. Fish Stem Cell Cultures

    OpenAIRE

    Ni Hong, Zhendong Li, Yunhan Hong

    2011-01-01

    Stem cells have the potential for self-renewal and differentiation. First stem cell cultures were derived 30 years ago from early developing mouse embryos. These are pluripotent embryonic stem (ES) cells. Efforts towards ES cell derivation have been attempted in other mammalian and non-mammalian species. Work with stem cell culture in fish started 20 years ago. Laboratory fish species, in particular zebrafish and medaka, have been the focus of research towards stem cell cultures. Medaka is th...

  10. Stem Cell Separation Technologies

    OpenAIRE

    Zhu, Beili; Murthy, Shashi K

    2013-01-01

    Stem cell therapy and translational stem cell research require large-scale supply of stem cells at high purity and viability, thus leading to the development of stem cell separation technologies. This review covers key technologies being applied to stem cell separation, and also highlights exciting new approaches in this field. First, we will cover conventional separation methods that are commercially available and have been widely adapted. These methods include Fluorescence-activated cell so...

  11. Cell control report

    CERN Document Server

    2013-01-01

    Please note this is a Short Discount publication. This extensive report provides an essential overview of cells and their use as factory automation building blocks. The following issues are discussed in depth: Cell integration Cell software and standards Future technologies applied to cells Plus Cell control applications including: - rotary parts manufacturing - diesel engine component development - general cell control development at the General Electric Corporation - a vendor list.

  12. Dental mesenchymal stem cells

    OpenAIRE

    Kaukua, Nina

    2014-01-01

    Mesenchymal stem cells have been found in various tissues and act as source for renewal and repair. The mouse incisor tooth continuously grows throughout life, implicating that there are stem cell niches constantly contributing with cells. The composition of these stem cell niches is not fully understood. Here, we show that Schwann cells on the peripheral nerves in the close proximity to the incisor tooth constitute a stem cell niche. Transgenic mouse models were used to label ...

  13. Sickle Cell Information Center

    Science.gov (United States)

    ... Word Visual Art Historical Perspectives General Information Research Articles Books Primary Documents Images Sickle Cell on Instagram Sickle Cell Organizations State National International Newsletter NIH Report on Evidence- ...

  14. Cell-cell interactions promote mammary epithelial cell differentiation

    OpenAIRE

    1985-01-01

    Mammary epithelium differentiates in a stromal milieu of adipocytes and fibroblasts. To investigate cell-cell interactions that may influence mammary epithelial cell differentiation, we developed a co-culture system of murine mammary epithelium and adipocytes and other fibroblasts. Insofar as caseins are specific molecular markers of mammary epithelial differentiation, rat anti-mouse casein monoclonal antibodies were raised against the three major mouse casein components to study this interac...

  15. Fusion with stem cell makes the hepatocellular carcinoma cells similar to liver tumor-initiating cells

    OpenAIRE

    Wang, Ran; Chen, Shuxun; Li, Changxian; Ng, Kevin Tak Pan; Kong, Chi-Wing; Cheng, Jinping; Cheng, Shuk Han; Li, Ronald A.; Lo, Chung Mau; Man, Kwan; Sun, Dong

    2016-01-01

    Background Cell fusion is a fast and highly efficient technique for cells to acquire new properties. The fusion of somatic cells with stem cells can reprogram somatic cells to a pluripotent state. Our research on the fusion of stem cells and cancer cells demonstrates that the fused cells can exhibit stemness and cancer cell-like characteristics. Thus, tumor-initiating cell-like cells are generated. Methods We employed laser-induced single-cell fusion technique to fuse the hepatocellular carci...

  16. A comparative study on poly(xylitol sebacate) and poly(glycerol sebacate): mechanical properties, biodegradation and cytocompatibility

    International Nuclear Information System (INIS)

    In order to develop degradable elastomers with a satisfactory combination of flexibility and enzyme-mediated degradation rate, the mechanical properties, enzymatic degradation kinetics and biocompatibility of poly(xylitol sebcate) (PXS) has been systematically investigated in comparison with poly(glycerol sebacate) (PGS). Under the same level of crosslinked density, the PXS elastomer networks have approximately twice the stretchability (elongation at break) of their PGS counterparts. This observation is attributable to the relatively longer and more orientable xylitol monomers, compared with glycerol molecules. Although xylitol monomers have two more hydroxyl groups, we, surprisingly, found that the hydrophilic side chains did not accelerate the water attack on the ester bonds of the PXS network, compared with their PGS counterpart. This observation was attributed to a steric hindrance effect, i.e. the large-sized hydroxyl groups can shield ester bonds from the attack of water molecules. In conclusion, the use of polyols of more than three –OH groups is an effective approach enhancing flexibility, whilst maintaining the degradation rate of polyester elastomers. Further development could be seen in the copolymerization of PPS with appropriate thermoplastic polyesters, such as poly(lactic acid) and polyhydroxyalkanoate. (paper)

  17. Preliminary Investigation of the Dissolution Behavior, Cytocompatibility, Effects of Fibrinogen Conformation and Platelet Adhesion for Radiopaque Embolic Particles

    OpenAIRE

    Daniel Boyd; Robert J. Abraham; Rainey, Jan K.; Aisling Coughlan; Mark R. Towler; Sharon Kehoe; Marie-Laurence Tremblay

    2013-01-01

    Experimental embolic particles based on a novel zinc-silicate glass system have been biologically evaluated for potential consideration in transcatheter arterial embolization procedures. In addition to controlling the cytotoxicity and haemocompatibility for such embolic particles, its glass structure may mediate specific responses via dissolution in the physiological environment. In a 120 h in-vitro dissolution study, ion release levels for silicon (Si4+), sodium (Na+), calcium (Ca2+), zinc (...

  18. Corrosion resistance, surface mechanical properties, and cytocompatibility of plasma immersion ion implantation-treated nickel-titanium shape memory alloys.

    Science.gov (United States)

    Yeung, K W K; Poon, R W Y; Liu, X Y; Ho, J P Y; Chung, C Y; Chu, P K; Lu, W W; Chan, D; Cheung, K M C

    2005-11-01

    Nickel-titanium shape memory alloys are promising materials in orthopedic applications because of their unique properties. However, for prolonged use in a human body, deterioration of the corrosion resistance of the materials becomes a critical issue because of the increasing possibility of deleterious ions released from the substrate to living tissues. We have investigated the use of nitrogen, acetylene, and oxygen plasma immersion ion implantation (PIII) to improve the corrosion resistance and mechanical properties of the materials. Our results reveal that the corrosion resistance and mechanical properties such as hardness and elastic modulus are significantly enhanced after surface treatment. The release of nickel is drastically reduced as compared with the untreated control. In addition, our in vitro tests show that the plasma-treated surfaces are well tolerated by osteoblasts. Among the three types of samples, the best biological effects are observed on the nitrogen PIII samples. PMID:16078209

  19. Highly luminescent and cytocompatible cationic Ag2S NIR-emitting quantum dots for optical imaging and gene transfection

    OpenAIRE

    Duman, Fatma Demir; Hocaoğlu, Ibrahim; Kiraz, Alper; Acar, Havva Yagci; Ozturk, Deniz Gulfem; Gozuacik, Devrim

    2015-01-01

    The development of non-toxic theranostic nanoparticles capable of delivering a therapeutic cargo and providing a means for diagnosis is one of the most challenging tasks in nano-biotechnology. Gene therapy is a very important mode of therapy and polyethyleneimine (PEI) is one of the most successful vehicles for gene transfection, yet poses significant toxicity. Optical imaging utilizing quantum dots is one of the newer but fast growing diagnostic modalities, which requires non-toxic, highly l...

  20. In vitro cytocompatibility study of a medical beta -type Ti-35.5Nb-5.7Ta titanium alloy

    OpenAIRE

    Burugapalli, K; M Razavi; Zhou, L; Huang, Y.

    2016-01-01

    This research was part of a European Commission funded research project for the development of a new generation of titanium based orthopaedic biomaterials. In particular, hip implants of a -type Ti-35.5Nb-5.7Ta alloy were fabricated by the powder metallurgy route. An advanced surface treatment technology of Laser Engineered Net Shaping (LENS) was used to apply a ZrO2/Zr coating on the implant surfaces where relative movement takes place between the implant and the bone, in order to enhance t...

  1. Cancer stem cell-like cells from a single cell of oral squamous carcinoma cell lines

    Energy Technology Data Exchange (ETDEWEB)

    Felthaus, O. [Department of Operative Dentistry and Periodontology, University of Regensburg (Germany); Department of Oral and Maxillofacial Surgery, University of Regensburg (Germany); Ettl, T.; Gosau, M.; Driemel, O. [Department of Oral and Maxillofacial Surgery, University of Regensburg (Germany); Brockhoff, G. [Department of Gynecology and Obstetrics, University of Regensburg (Germany); Reck, A. [Department of Oral and Maxillofacial Surgery, University of Regensburg (Germany); Zeitler, K. [Institute of Pathology, University of Regensburg (Germany); Hautmann, M. [Department of Radiotherapy, University of Regensburg (Germany); Reichert, T.E. [Department of Oral and Maxillofacial Surgery, University of Regensburg (Germany); Schmalz, G. [Department of Operative Dentistry and Periodontology, University of Regensburg (Germany); Morsczeck, C., E-mail: christian.morsczeck@klinik.uni-regensburg.de [Department of Operative Dentistry and Periodontology, University of Regensburg (Germany)

    2011-04-01

    Research highlights: {yields} Four oral squamous cancer cell lines (OSCCL) were analyzed for cancer stem cells (CSCs). {yields} Single cell derived colonies of OSCCL express CSC-marker CD133 differentially. {yields} Monoclonal cell lines showed reduced sensitivity for Paclitaxel. {yields} In situ CD133{sup +} cells are slow cycling (Ki67-) indicating a reduced drug sensitivity. {yields} CD133{sup +} and CSC-like cells can be obtained from single colony forming cells of OSCCL. -- Abstract: Resistance of oral squamous cell carcinomas (OSCC) to conventional chemotherapy or radiation therapy might be due to cancer stem cells (CSCs). The development of novel anticancer drugs requires a simple method for the enrichment of CSCs. CSCs can be enriched from OSCC cell lines, for example, after cultivation in serum-free cell culture medium (SFM). In our study, we analyzed four OSCC cell lines for the presence of CSCs. CSC-like cells could not be enriched with SFM. However, cell lines obtained from holoclone colonies showed CSC-like properties such as a reduced rate of cell proliferation and a reduced sensitivity to Paclitaxel in comparison to cells from the parental lineage. Moreover, these cell lines differentially expressed the CSC-marker CD133, which is also upregulated in OSCC tissues. Interestingly, CD133{sup +} cells in OSCC tissues expressed little to no Ki67, the cell proliferation marker that also indicates reduced drug sensitivity. Our study shows a method for the isolation of CSC-like cell lines from OSCC cell lines. These CSC-like cell lines could be new targets for the development of anticancer drugs under in vitro conditions.

  2. Cancer stem cell-like cells from a single cell of oral squamous carcinoma cell lines

    International Nuclear Information System (INIS)

    Research highlights: → Four oral squamous cancer cell lines (OSCCL) were analyzed for cancer stem cells (CSCs). → Single cell derived colonies of OSCCL express CSC-marker CD133 differentially. → Monoclonal cell lines showed reduced sensitivity for Paclitaxel. → In situ CD133+ cells are slow cycling (Ki67-) indicating a reduced drug sensitivity. → CD133+ and CSC-like cells can be obtained from single colony forming cells of OSCCL. -- Abstract: Resistance of oral squamous cell carcinomas (OSCC) to conventional chemotherapy or radiation therapy might be due to cancer stem cells (CSCs). The development of novel anticancer drugs requires a simple method for the enrichment of CSCs. CSCs can be enriched from OSCC cell lines, for example, after cultivation in serum-free cell culture medium (SFM). In our study, we analyzed four OSCC cell lines for the presence of CSCs. CSC-like cells could not be enriched with SFM. However, cell lines obtained from holoclone colonies showed CSC-like properties such as a reduced rate of cell proliferation and a reduced sensitivity to Paclitaxel in comparison to cells from the parental lineage. Moreover, these cell lines differentially expressed the CSC-marker CD133, which is also upregulated in OSCC tissues. Interestingly, CD133+ cells in OSCC tissues expressed little to no Ki67, the cell proliferation marker that also indicates reduced drug sensitivity. Our study shows a method for the isolation of CSC-like cell lines from OSCC cell lines. These CSC-like cell lines could be new targets for the development of anticancer drugs under in vitro conditions.

  3. Mesenchymal stem cell like (MSCl) cells generated from human embryonic stem cells support pluripotent cell growth

    International Nuclear Information System (INIS)

    Highlights: ► MSC like cells were derived from hESC by a simple and reproducible method. ► Differentiation and immunosuppressive features of MSCl cells were similar to bmMSC. ► MSCl cells as feeder cells support the undifferentiated growth of hESC. -- Abstract: Mesenchymal stem cell like (MSCl) cells were generated from human embryonic stem cells (hESC) through embryoid body formation, and isolated by adherence to plastic surface. MSCl cell lines could be propagated without changes in morphological or functional characteristics for more than 15 passages. These cells, as well as their fluorescent protein expressing stable derivatives, efficiently supported the growth of undifferentiated human embryonic stem cells as feeder cells. The MSCl cells did not express the embryonic (Oct4, Nanog, ABCG2, PODXL, or SSEA4), or hematopoietic (CD34, CD45, CD14, CD133, HLA-DR) stem cell markers, while were positive for the characteristic cell surface markers of MSCs (CD44, CD73, CD90, CD105). MSCl cells could be differentiated toward osteogenic, chondrogenic or adipogenic directions and exhibited significant inhibition of mitogen-activated lymphocyte proliferation, and thus presented immunosuppressive features. We suggest that cultured MSCl cells can properly model human MSCs and be applied as efficient feeders in hESC cultures.

  4. SMOOTH MUSCLE STEM CELLS

    Science.gov (United States)

    Vascular smooth muscle cells (SMCs) originate from multiple types of progenitor cells. In the embryo, the most well-studied SMC progenitor is the cardiac neural crest stem cell. Smooth muscle differentiation in the neural crest lineage is controlled by a combination of cell intrinsic factors, includ...

  5. CELL VOLUME CONFERENCES

    OpenAIRE

    V. Štrbák

    2016-01-01

    This mini-review describes the history of cell volume conferences with the emphasis on the research of cell volume sensitive peptide exocytosis initiated by Prof. Monte A. Greer as well as the recent achievements on the study of the mechanisms of cell volume adjustment and their implications in the regulation of metabolism, gene expression, cell proliferation and death.

  6. Sickle Cell Disease

    Science.gov (United States)

    ... sickle cell disease? Sickle cell disease, also called sickle cell anemia, is a hereditary condition (which means it runs ... or blocks blood and oxygen reaching nearby tissues. Sickle cell disease ... the whites of the eyes) Anemia (the decreased ability of the blood to carry ...

  7. Fluorescence activated cell sorting.

    Science.gov (United States)

    Bonner, W. A.; Hulett, H. R.; Sweet, R. G.; Herzenberg, L. A.

    1972-01-01

    An instrument has been developed for sorting biological cells. The cells are rendered differentially fluorescent and incorporated into a small liquid stream illuminated by a laser beam. The cells pass sequentially through the beam, and fluorescent light from the cells gives rise to electrical signals. The stream is broken into a series of uniform size drops downstream of the laser. The cell signals are used to give appropriate electrostatic charges to drops containing the cells. The drops then pass between two charged plates and are deflected to appropriate containers. The system has proved capable of providing fractions containing large numbers of viable cells highly enriched in a particular functional type.

  8. When Blood Cells Bend: Understanding Sickle Cell Disease

    Science.gov (United States)

    ... please review our exit disclaimer . Subscribe When Blood Cells Bend Understanding Sickle Cell Disease For people who don’t suspect they ... Cells Bend Wise Choices Links Living with Sickle Cell Disease See a sickle cell disease expert regularly. ...

  9. The cell cycle as a brake for β-cell regeneration from embryonic stem cells

    OpenAIRE

    El-Badawy, Ahmed; El-Badri, Nagwa

    2016-01-01

    The generation of insulin-producing β cells from stem cells in vitro provides a promising source of cells for cell transplantation therapy in diabetes. However, insulin-producing cells generated from human stem cells show deficiency in many functional characteristics compared with pancreatic β cells. Recent reports have shown molecular ties between the cell cycle and the differentiation mechanism of embryonic stem (ES) cells, assuming that cell fate decisions are controlled by the cell cycle ...

  10. Cancer Stem Cells

    OpenAIRE

    Katarzyna Wieczorek; Jolanta Niewiarowska

    2008-01-01

    Cancer stem cell theory gains increasingly greater significance in the world of medicine. Numerous findings of scientific research in vivo and in vitro indicate that it is the population of undifferentiated, self-renewing cells which is responsible for recurrence of cancer and metastasis. Similarly to normal stem cells, cancer stem cells (CSC) function in the environment of the other cells of the organism, called the niche, where they receive signals for differentiation and proliferation proc...

  11. Cell fusion of bone marrow cells and somatic cell reprogramming by embryonic stem cells

    OpenAIRE

    Bonde, Sabrina; Pedram, Mehrdad; Stultz, Ryan; Zavazava, Nicholas

    2010-01-01

    Bone marrow transplantation is a curative treatment for many diseases, including leukemia, autoimmune diseases, and a number of immunodeficiencies. Recently, it was claimed that bone marrow cells transdifferentiate, a much desired property as bone marrow cells are abundant and therefore could be used in regenerative medicine to treat incurable chronic diseases. Using a Cre/loxP system, we studied cell fusion after bone marrow transplantation. Fused cells were chiefly Gr-1+, a myeloid cell mar...

  12. Hepatic stem cell niches

    OpenAIRE

    Kordes, Claus; Häussinger, Dieter

    2013-01-01

    Stem cell niches are special microenvironments that maintain stem cells and control their behavior to ensure tissue homeostasis and regeneration throughout life. The liver has a high regenerative capacity that involves stem/progenitor cells when the proliferation of hepatocytes is impaired. In recent years progress has been made in the identification of potential hepatic stem cell niches. There is evidence that hepatic progenitor cells can originate from niches in the canals...

  13. Stem Cell Networks

    OpenAIRE

    Werner, Eric

    2016-01-01

    We present a general computational theory of stem cell networks and their developmental dynamics. Stem cell networks are special cases of developmental control networks. Our theory generates a natural classification of all possible stem cell networks based on their network architecture. Each stem cell network has a unique topology and semantics and developmental dynamics that result in distinct phenotypes. We show that the ideal growth dynamics of multicellular systems generated by stem cell ...

  14. Stem cell mechanobiology

    OpenAIRE

    David A. Lee; Knight, Martin M.; Jonathan J Campbell; Bader, Dan L.

    2010-01-01

    Stem cells are undifferentiated cells that are capable of proliferation, self-maintenance and differentiation towards specific cell phenotypes. These processes are controlled by a variety of cues including physicochemical factors associated with the specific mechanical environment in which the cells reside. The control of stem cell biology through mechanical factors remains poorly understood and is the focus of the developing field of mechanobiology. This review provides an insight into the c...

  15. Embryonic Stem Cell Markers

    OpenAIRE

    Lan Ma; Liang Li; Wenxiu Zhao; Xiang Ji; Fangfang Zhang

    2012-01-01

    Embryonic stem cell (ESC) markers are molecules specifically expressed in ES cells. Understanding of the functions of these markers is critical for characterization and elucidation for the mechanism of ESC pluripotent maintenance and self-renewal, therefore helping to accelerate the clinical application of ES cells. Unfortunately, different cell types can share single or sometimes multiple markers; thus the main obstacle in the clinical application of ESC is to purify ES cells from other type...

  16. Limbal stem cell transplantation

    OpenAIRE

    Fernandes Merle; Sangwan Virender; Rao Srinivas; Basti Surendra; Sridhar Mittanamalli; Bansal Aashish; Dua Harminder

    2004-01-01

    The past two decades have witnessed remarkable progress in limbal stem cell transplantation. In addition to harvesting stem cells from a cadaver or a live related donor, it is now possible to cultivate limbal stem cells in vitro and then transplant them onto the recipient bed. A clear understanding of the basic disease pathology and a correct assessment of the extent of stem cell deficiency are essential. A holistic approach towards management of limbal stem cell deficiency is needed. This ...

  17. Intraoperative Stem Cell Therapy

    OpenAIRE

    Coelho, Mónica Beato; Cabral, Joaquim M. S.; Karp, Jeffrey M.

    2012-01-01

    Stem cells hold significant promise for regeneration of tissue defects and disease-modifying therapies. Although numerous promising stem cell approaches are advancing in clinical trials, intraoperative stem cell therapies offer more immediate hope by integrating an autologous cell source with a well-established surgical intervention in a single procedure. Herein, the major developments in intraoperative stem cell approaches, from in vivo models to clinical studies, are reviewed, and the poten...

  18. The leukemic stem cell

    OpenAIRE

    Jordan, Craig T.

    2007-01-01

    Malignant stem cells have recently been described as the source of several types of human cancer. These unique cell types are typically rare and possess properties that are distinct from most other tumor cells. The properties of leukemic stem cells indicate that current chemotherapy drugs will not be effective. The use of current cytotoxic agents is not effective in leukemia because the agents target both the leukemic and normal stem cell populations. Consequently, new strategies are required...

  19. Stem cell biobanks.

    Science.gov (United States)

    Bardelli, Silvana

    2010-04-01

    Stem cells contribute to innate healing and harbor a promising role for regenerative medicine. Stem cell banking through long-term storage of different stem cell platforms represents a fundamental source to preserve original features of stem cells for patient-specific clinical applications. Stem cell research and clinical translation constitute fundamental and indivisible modules catalyzed through biobanking activity, generating a return of investment. PMID:20560026

  20. Mechanically facilitated cell-cell electrofusion.

    OpenAIRE

    Jaroszeski, M. J.; Gilbert, R.; Fallon, P.G.; Heller, R

    1994-01-01

    Apparatus and methods were developed to enable mechanically facilitated cell-cell electrofusion to be performed. The apparatus and methods mechanically place cells in contact before fusion. The key component of this fusion system was a newly developed fusion chamber. The chamber was composed of two functionally identical electrodes that were housed in a multi-layer structure. The layers functioned as support for the electrodes. They also allowed adjustment of the distance between opposing ele...

  1. Optimizing stem cell culture.

    Science.gov (United States)

    van der Sanden, Boudewijn; Dhobb, Mehdi; Berger, François; Wion, Didier

    2010-11-01

    Stem cells always balance between self-renewal and differentiation. Hence, stem cell culture parameters are critical and need to be continuously refined according to progress in our stem cell biology understanding and the latest technological developments. In the past few years, major efforts have been made to define more precisely the medium composition in which stem cells grow or differentiate. This led to the progressive replacement of ill-defined additives such as serum or feeder cell layers by recombinant cytokines or growth factors. Another example is the control of the oxygen pressure. For many years cell cultures have been done under atmospheric oxygen pressure which is much higher than the one experienced by stem cells in vivo. A consequence of cell metabolism is that cell culture conditions are constantly changing. Therefore, the development of high sensitive monitoring processes and control algorithms is required for ensuring cell culture medium homeostasis. Stem cells also sense the physical constraints of their microenvironment. Rigidity, stiffness, and geometry of the culture substrate influence stem cell fate. Hence, nanotopography is probably as important as medium formulation in the optimization of stem cell culture conditions. Recent advances include the development of synthetic bioinformative substrates designed at the micro- and nanoscale level. On going research in many different fields including stem cell biology, nanotechnology, and bioengineering suggest that our current way to culture cells in Petri dish or flasks will soon be outdated as flying across the Atlantic Ocean in the Lindbergh's plane. PMID:20803548

  2. Mast cells enhance T cell activation: Importance of mast cell-derived TNF

    Science.gov (United States)

    Nakae, Susumu; Suto, Hajime; Kakurai, Maki; Sedgwick, Jonathon D.; Tsai, Mindy; Galli, Stephen J.

    2005-05-01

    Mast cells are not only important effector cells in immediate hypersensitivity reactions and immune responses to pathogens but also can contribute to T cell-mediated disorders. However, the mechanisms by which mast cells might influence T cells in such settings are not fully understood. We find that mast cells can enhance proliferation and cytokine production in multiple T cell subsets. Mast cell-dependent enhancement of T cell activation can be promoted by FcRI-dependent mast cell activation, TNF production by both mast cells and T cells, and mast cell-T cell contact. However, at high concentrations of cells, mast cells can promote T cell activation independent of IgE or TNF. Finally, mast cells also can promote T cell activation by means of soluble factors. These findings identify multiple mechanisms by which mast cells can influence T cell proliferation and cytokine production. allergy | asthma | autoimmunity | cytokines | immune response

  3. Living with Sickle Cell Disease

    Science.gov (United States)

    ... sickle cell disease, go to the Health Topics Sickle Cell Anemia article. Living With and Managing Sickle Cell Disease ( ... the most severe form of sickle cell disease, sickle cell anemia, Tiffany has lived with the symptoms and complications ...

  4. What Causes Sickle Cell Disease?

    Science.gov (United States)

    ... sickle cell disease, go to the Health Topics Sickle Cell Anemia article. Living With and Managing Sickle Cell Disease ( ... the most severe form of sickle cell disease, sickle cell anemia, Tiffany has lived with the symptoms and complications ...

  5. Lung Cancer Stem Cells

    Directory of Open Access Journals (Sweden)

    Sharon R. Pine

    2008-01-01

    Full Text Available Lung cancer remains a major cause of cancer-related lethality because of high incidence and recurrence in spite of significant advances in staging and therapies. Recent data indicates that stem cells situated throughout the airways may initiate cancer formation. These putative stem cells maintain protumorigenic characteristics including high proliferative capacity, multipotent differentiation, drug resistance and long lifespan relative to other cells. Stem cell signaling and differentiation pathways are maintained within distinct cancer types, and destabilization of this machinery may participate in maintenance of cancer stem cells. Characterization of lung cancer stem cells is an area of active research and is critical for developing novel therapies. This review summarizes the current knowledge on stem cell signaling pathways and cell markers used to identify the lung cancer stem cells.

  6. What are Stem Cells?

    Directory of Open Access Journals (Sweden)

    Ahmadshah Farhat

    2014-05-01

    Full Text Available   Stem cells are undifferentiated self regenerating multi potential cells. There are three types of stem cells categories by the ability to form after cells and correlated with the body’s development process. Totipotent: these stem cells can form an entire organism such as fertilized egg. Ploripotent: ploripotent cells are those that can form any cell in the body but cannot form an entire organism such as developing embryo’s totipotent cells become ploripotent  Multipotent: Multi potent stem cells are those that can only form specific cells in the body such as blood cells based. Based on the sources of stem cells we have three types of these cells: Autologous: Sources of the patient own cells are (Autologous either the cells from patient own body or his or her cord blood. For this type of transplant the physician now usually collects the periphery rather than morrow because the procedure is easier on like a bane morrow harvest it take place outside of an operating room, and the patient does not to be under general unsetting . Allogenic: Sources of stem cells from another donore are primarily relatives (familial allogenic or completely unrelated donors. Xenogenic: In these stem cells from different species are transplanted e .g striatal porcine fetal mesan cephalic (FVM xenotransplants for Parkinson’s disease. On sites of isolation such as embryo, umbilical cord and other body tissues stem cells are named embnyonic, cord blood, and adult stem cells. The scope of results and clinical application of stem cells are such as: Neurodegenerative conditions (MS,ALS, Parkinson’s, Stroke, Ocular disorders- Glaucoma, retinitis Pigmentosa (RP, Auto Immune Conditions (Lupus, MS,R. arthritis, Diabetes, etc, Viral Conditions (Hepatitis C and AIDS, Heart Disease, Adrenal Disorders, Injury(Nerve, Brain, etc, Anti aging (hair, skin, weight control, overall well being/preventive, Emotional disorders, Organ / Tissue Cancers, Blood cancers, Blood diseases

  7. Pluripotent Stem Cells for Schwann Cell Engineering

    NARCIS (Netherlands)

    Ma, Ming-San; Boddeke, Erik; Copray, Sjef

    2015-01-01

    Tissue engineering of Schwann cells (SCs) can serve a number of purposes, such as in vitro SC-related disease modeling, treatment of peripheral nerve diseases or peripheral nerve injury, and, potentially, treatment of CNS diseases. SCs can be generated from autologous stem cells in vitro by recapitu

  8. Assessment of pancreas cells

    Science.gov (United States)

    Vanoss, C. J.

    1978-01-01

    Pancreatic islets were obtained from guinea pig pancreas by the collagenase method and kept alive in tissue culture prior to further studies. Pancreas cell morphology was studied by standard histochemical techniques using light microscopy. Preparative vertical electrophoresis-levitation of dispersed fetal guinea pig pancreas cells was conducted in phosphate buffer containing a heavy water (D20) gradient which does not cause clumping of cells or alter the osmolarity of the buffers. The faster migrating fractions tended to be enriched in beta-cell content. Alpha and delta cells were found to some degree in most fractions. A histogram showing the cell count distribution is included.

  9. Resident Peritoneal NK cells

    OpenAIRE

    Gonzaga, Rosemary; Matzinger, Polly; Perez-Diez, Ainhoa

    2011-01-01

    Here we describe a new population of NK cells that reside in the normal, un-inflamed peritoneal cavity. Phenotypically, they share some similarities with the small population of CD49b negative, CD27 positive immature splenic NK cells, and liver NK cells but differ in their expression of CD62L, TRAIL and EOMES. Functionally, the peritoneal NK cells resemble the immature splenic NK cells in their production of IFN-γ, GM-CSF and TNF-α and in the killing of YAC-1 target cells. We also found that ...

  10. Load Cell Optimization

    OpenAIRE

    Garðar Páll Gíslason 1979

    2011-01-01

    A load cell is a small object which has only one goal and that is to measure load. This is an old invention from the mid-eighteenth century and remains very popular today. Load cells are only one portion of a bigger totality. That is why the shape of the load cell changes between objects. Optimization of a load cell is an effective way to get the highest signal from the cell. The main object of this thesis is optimization of a load cell which is a part of the Rheo Knee® from Össur. This kn...

  11. Cytotoxicity and cellular uptake of ZnS:Mn nanocrystals biofunctionalized with chitosan and aminoacids

    Digital Repository Service at National Institute of Oceanography (India)

    Augustine, M.S.; Anas, A.; Das, A.V.; Sreekanth, S.; Jayalekshmi, S.

    biofunctionalized with chitosan, l-citrulline, glycine, l-artginine, l-serine and l-histidine showed least toxicity up to 10 nM concentrations in mouse fibroblast L929 cells, which further confirms their cytocompatibility. Also the ZnS:Mn nanocrystals...

  12. Multipotent adult progenitor cell and stem cell plasticity

    OpenAIRE

    Jahagirdar, Balkrishna N; Verfaillie, Catherine

    2005-01-01

    Stem cells are defined by their biological function. A stem cell is an undifferentiated cell that self-renews to maintain the stem cell pool and at the single-cell level differentiates into more than one mature, functional cell. In addition, when transplanted, a stem cell should be capable of replacing a damaged organ or tissue for the lifetime of the recipient. Some would argue that stem cells should also be capable of functionally integrating into nondamaged tissues. Stem cells are critical...

  13. Cellular reactions to patterned biointerfaces

    OpenAIRE

    Schulte, Vera Antonie

    2012-01-01

    The subject of this thesis is to study cellular reactions to topographically, mechanically and biochemically tunable polymeric biomaterials. Different aspects of in vitro cell-biomaterial interactions were systematically studied with the murine fibroblast cell line NIH L929 and primary human dermal fibroblasts (HDFs). Besides a general cytocompatibility assessment of the applied materials and the quantification of cell adhesion per se, cell morphological changes (e.g. cell spreading) and intr...

  14. Epidermal Stem Cells

    Directory of Open Access Journals (Sweden)

    Osman Köse

    2015-03-01

    Full Text Available The epidermis is the outermost layer of the human skin and comprises a multilayered epithelium, the interfollicular epidermis, with associated hair follicles, sebaceous glands, and eccrine sweat glands. There are many origins of stem cells in the skin and skin appendages. These stem cells are localized in different part of the pilosebaseous units and also express many different genes. Epidermal stem cells in the pilosebaseous units not only ensure the maintenance of epidermal homeostasis and hair regeneration, but also contribute to repair of the epidermis after injury. In recent years, human induced pluripotent skin stem cells are produced from the epidermal cells such as keratinocytes, fibroblasts and melanocytes. These cells can be transdifferentiated to embriyonic stem cells. Human induced pluripotent stem cells have potential applications in cell replacement therapy and regenerative medicine. These cells provide a means to create valuable tools for basic research and may also produce a source of patient-matched cells for regenerative therapies. In this review, we aimed an overview of epidermal stem cells for better understanding their functions in the skin. Skin will be main organ for using the epidermal cells for regenerative medicine in near future.

  15. Regulatory T cells and B cells: implication on autoimmune diseases

    OpenAIRE

    Wang, Ping; Zheng, Song Guo

    2013-01-01

    The regulatory T (Treg) cells play an important role in the maintenance of homeostasis and the prevention of autoimmune diseases. Although most studies are focusing on the role of Treg cells in T cells and T cells-mediated diseases, these cells also directly affect B cells and other non-T cells. This manuscript updates the role of Treg cells on the B cells and B cell-mediated diseases. In addition, the mechanisms whereby Treg cells suppress B cell responses have been discussed.

  16. Giant Cell Arteritis

    Science.gov (United States)

    Giant cell arteritis is a disorder that causes inflammation of your arteries, usually in the scalp, neck, and arms. ... arteries, which keeps blood from flowing well. Giant cell arteritis often occurs with another disorder called polymyalgia ...

  17. Sickle Cell Trait

    Science.gov (United States)

    ... About Us Information For... Media Policy Makers Sickle Cell Trait Language: English Español (Spanish) Recommend on Facebook ... the trait on to their children. How Sickle Cell Trait is Inherited If both parents have SCT, ...

  18. Sickle Cell Disease Quiz

    Science.gov (United States)

    ... About Us Information For... Media Policy Makers Sickle Cell Disease Quiz Language: English Español (Spanish) Recommend on ... True or False: Only African Americans get sickle cell disease. A True B False 2. True or ...

  19. Toward 'SMART' stem cells.

    Science.gov (United States)

    Cheng, T

    2008-01-01

    Stem cell research is at the heart of regenerative medicine, which holds great promise for the treatment of many devastating disorders. However, in addition to hurdles posed by well-publicized ethical issues, this emerging field presents many biological challenges. What is a stem cell? How are embryonic stem cells different from adult stem cells? What are the physiological bases for therapeutically acceptable stem cells? In this editorial review, I will briefly discuss these superficially simple but actually rather complex issues that surround this fascinating cell type. The goal of this special issue on stem cells in Gene Therapy is to review some fundamental and critical aspects of current stem cell research that have translational potential. PMID:18046429

  20. Anaplastic Large Cell Lymphoma

    Science.gov (United States)

    Anaplastic Large Cell Lymphoma Overview Lymphoma is the most common blood cancer. The two main forms of lymphoma are ... organs, and can accumulate to form tumors. Anaplastic large cell lymphoma (ALCL) is arare type of NHL, ...

  1. NIA Aging Cell Repository

    Data.gov (United States)

    Federal Laboratory Consortium — To facilitate aging research on cells in culture, the NIA provides support for the NIA Aging Cell Repository, located at the Coriell Institute for Medical Research...

  2. Mammalian cell biology

    International Nuclear Information System (INIS)

    This section contains summaries of research on mechanisms of lethality and radioinduced changes in mammalian cell properties, new cell systems for the study of the biology of mutation and neoplastic transformation, and comparative properties of ionizing radiations

  3. What Are Islet Cells?

    Science.gov (United States)

    ... Video Be Part of the Cure Commitment to Stem Cell Research Exercise + Drug Therapy Tibi Creates Garment to Benefit ... Video Be Part of the Cure Commitment to Stem Cell Research Exercise + Drug Therapy Tibi Creates Garment to Benefit ...

  4. Sickle cell anemia.

    OpenAIRE

    ŘÍHOVÁ, Tereza

    2013-01-01

    This thesis is about the disease called sickle cell anemia, or drepanocytosis. In this thesis is described the history of the disease, pathophysiology, laboratory features, various clinical features, diferencial diagnosis, quality of life in sickle cell anemia and therapy.

  5. Cell signaling review series

    Institute of Scientific and Technical Information of China (English)

    Aiming Lin; Zhenggang Liu

    2008-01-01

    @@ Signal transduction is pivotal for many, if not all, fundamental cellular functions including proliferation, differentiation, transformation and programmed cell death. Deregulation of cell signaling may result in certain types of cancers and other human diseases.

  6. Renal cell carcinoma

    Science.gov (United States)

    Renal cell carcinoma is a type of kidney cancer that starts in the lining of very small tubes (tubules) in the kidney. ... cancer; Kidney cancer; Hypernephroma; Adenocarcinoma of renal cells; Cancer - kidney

  7. Sickle Cell Tests

    Science.gov (United States)

    ... be limited. Home Visit Global Sites Search Help? Sickle Cell Tests Share this page: Was this page helpful? ... else I should know? How is it used? Sickle cell tests are used to identify the presence of ...

  8. Sickle cell anemia

    Science.gov (United States)

    ... for avascular necrosis of the hip Surgery for eye problems Treatment for overuse or abuse of narcotic pain medicines Wound care for leg ulcers Bone marrow or stem cell transplants can cure sickle cell anemia, but this treatment ...

  9. Prostate cancer stem cells

    OpenAIRE

    Tu, Shi-Ming; Lin, Sue-Hwa

    2011-01-01

    Stem cells have long been implicated in prostate glandular formation. The prostate undergoes regression after androgen deprivation and regeneration after testosterone replacement. Regenerative studies suggest that these cells are found in the proximal ducts and basal layer of the prostate. Many characteristics of prostate cancer indicate that it originates from stem cells. For example, the putative AR− status of prostate stem cells renders them inherently insensitive to androgen blockade ther...

  10. Lung Cancer Stem Cells

    OpenAIRE

    Pine, Sharon R.; Blair Marshall; Lyuba Varticovski

    2008-01-01

    Lung cancer remains a major cause of cancer-related lethality because of high incidence and recurrence in spite of significant advances in staging and therapies. Recent data indicates that stem cells situated throughout the airways may initiate cancer formation. These putative stem cells maintain protumorigenic characteristics including high proliferative capacity, multipotent differentiation, drug resistance and long lifespan relative to other cells. Stem cell signaling and differentiation p...

  11. Nanoelectrochemistry of mammalian cells

    OpenAIRE

    Sun, Peng; Laforge, François O.; Abeyweera, Thushara P.; Rotenberg, Susan A.; Carpino, James; Mirkin, Michael V.

    2008-01-01

    There is a significant current interest in development of new techniques for direct characterization of the intracellular redox state and high-resolution imaging of living cells. We used nanometer-sized amperometric probes in combination with the scanning electrochemical microscope (SECM) to carry out spatially resolved electrochemical experiments in cultured human breast cells. With the tip radius ≈1,000 times smaller than that of a cell, an electrochemical probe can penetrate a cell and tra...

  12. Optimizing stem cell culture.

    OpenAIRE

    van der Sanden, Boudewijn; Dhobb, Mehdi; Berger, François; Wion, Didier

    2010-01-01

    International audience Stem cells always balance between self-renewal and differentiation. Hence, stem cell culture parameters are critical and need to be continuously refined according to progress in our stem cell biology understanding and the latest technological developments. In the past few years, major efforts have been made to define more precisely the medium composition in which stem cells grow or differentiate. This led to the progressive replacement of ill-defined additives such a...

  13. STEM CELLS AND PROTEOMICS

    Institute of Scientific and Technical Information of China (English)

    ZHOU Yong-ming; GUO Tian-nan; HUANG Shi-ang

    2006-01-01

    The distinctive features of proteomics are large-scale and high throughput. The key techniques of proteomics are two-dimensional gel electrophoresis, mass spectrometry and bioinformatics. Stem cell can differentiate into all kinds of cells, tissues and organs. There are many proteins and cytokines involved in the process of differentiation. Applying proteomics techniques to the research of the complex process of stem cell differentiation is of great importance to study the mechanism and applications of stem cell differentiation.

  14. Fish Stem Cell Cultures

    Directory of Open Access Journals (Sweden)

    Ni Hong, Zhendong Li, Yunhan Hong

    2011-01-01

    Full Text Available Stem cells have the potential for self-renewal and differentiation. First stem cell cultures were derived 30 years ago from early developing mouse embryos. These are pluripotent embryonic stem (ES cells. Efforts towards ES cell derivation have been attempted in other mammalian and non-mammalian species. Work with stem cell culture in fish started 20 years ago. Laboratory fish species, in particular zebrafish and medaka, have been the focus of research towards stem cell cultures. Medaka is the second organism that generated ES cells and the first that gave rise to a spermatogonial stem cell line capable of test-tube sperm production. Most recently, the first haploid stem cells capable of producing whole animals have also been generated from medaka. ES-like cells have been reported also in zebrafish and several marine species. Attempts for germline transmission of ES cell cultures and gene targeting have been reported in zebrafish. Recent years have witnessed the progress in markers and procedures for ES cell characterization. These include the identification of fish homologs/paralogs of mammalian pluripotency genes and parameters for optimal chimera formation. In addition, fish germ cell cultures and transplantation have attracted considerable interest for germline transmission and surrogate production. Haploid ES cell nuclear transfer has proven in medaka the feasibility of semi-cloning as a novel assisted reproductive technology. In this special issue on “Fish Stem Cells and Nuclear Transfer”, we will focus our review on medaka to illustrate the current status and perspective of fish stem cells in research and application. We will also mention semi-cloning as a new development to conventional nuclear transfer.

  15. Editorial: Stem Cell Engineering.

    Science.gov (United States)

    Cabral, Joaquim M S; Palecek, Sean P

    2015-10-01

    In recent years, the promise of stem cells as tools for basic research, in vitro diagnostics, and in vivo therapeutics is increasingly being realized. This Special issue of Biotechnology Journal explores recent advances in the emerging field of stem cell engineering, with a focus on applying engineering approaches to understanding stem cell biology and enabling translation of stem cells to commercial and clinical products. PMID:26447639

  16. Aneuploidy in stem cells

    OpenAIRE

    Garcia-Martinez, Jorge; Bakker, Bjorn; Schukken, Klaske M; Simon, Judith E; Foijer, Floris

    2016-01-01

    Stem cells hold enormous promise for regenerative medicine as well as for engineering of model systems to study diseases and develop new drugs. The discovery of protocols that allow for generating induced pluripotent stem cells (IPSCs) from somatic cells has brought this promise steps closer to reality. However, as somatic cells might have accumulated various chromosomal abnormalities, including aneuploidies throughout their lives, the resulting IPSCs might no longer carry the perfect bluepri...

  17. Blood cell labelling

    International Nuclear Information System (INIS)

    The labelling of blood cells in vitro for subsequent in vivo studies was one of the earliest applications of radioactive tracers in clinical medicine and laid the foundations for many important contributions to the advancement of knowledge of human blood cell pathophysiology. The characteristics required for satisfactory clinical studies, the mechanisms of cell labelling, the problems of radiation or chemical damage to the labelled cells and some examples of modern clinical applications are described and discussed. (Author)

  18. Skeletal (stromal) stem cells

    DEFF Research Database (Denmark)

    Abdallah, Basem M; Kermani, Abbas Jafari; Zaher, Walid;

    2015-01-01

    Skeletal (marrow stromal) stem cells (BMSCs) are a group of multipotent cells that reside in the bone marrow stroma and can differentiate into osteoblasts, chondrocytes and adipocytes. Studying signaling pathways that regulate BMSC differentiation into osteoblastic cells is a strategy for....../preadipocyte factor 1 (Dlk1/Pref-1), the Wnt co-receptor Lrp5 and intracellular kinases. This article is part of a Special Issue entitled: Stem Cells and Bone....

  19. Diagram of Cell to Cell Communication

    Science.gov (United States)

    2002-01-01

    Diagram depicts the importance of cell-cell communication as central to the understanding of cancer growth and progression, the focus of the NASA bioreactor demonstration system (BDS-05) investigation. Microgravity studies will allow us to unravel the signaling and communication between these cells with the host and potential development of therapies for the treatment of cancer metastasis. The NASA Bioreactor provides a low turbulence culture environment which promotes the formation of large, three-dimensional cell clusters. Due to their high level of cellular organization and specialization, samples constructed in the bioreactor more closely resemble the original tumor or tissue found in the body. The Bioreactor is rotated to provide gentle mixing of fresh and spent nutrient without inducing shear forces that would damage the cells. The work is sponsored by NASA's Office of Biological and Physical Research. The bioreactor is managed by the Biotechnology Cell Science Program at NASA's Johnson Space Center (JSC). NASA-sponsored bioreactor research has been instrumental in helping scientists to better understand normal and cancerous tissue development. In cooperation with the medical community, the bioreactor design is being used to prepare better models of human colon, prostate, breast and ovarian tumors. Cartilage, bone marrow, heart muscle, skeletal muscle, pancreatic islet cells, liver and kidney are just a few of the normal tissues being cultured in rotating bioreactors by investigators. Credit: Emory University.

  20. Antitumor Immunity Produced by the Liver Kupffer Cells, NK Cells, NKT Cells, and CD8+ CD122+ T Cells

    OpenAIRE

    Shuhji Seki; Hiroyuki Nakashima; Masahiro Nakashima; Manabu Kinoshita

    2011-01-01

    Mouse and human livers contain innate immune leukocytes, NK cells, NKT cells, and macrophage-lineage Kupffer cells. Various bacterial components, including Toll-like receptor (TLR) ligands and an NKT cell ligand ( α -galactocylceramide), activate liver Kupffer cells, which produce IL-1, IL-6, IL-12, and TNF. IL-12 activates hepatic NK cells and NKT cells to produce IFN- γ , which further activates hepatic T cells, in turn activating phagocytosis and cytokine production by Kupffer cells in a p...

  1. Molecular Mechanisms of HTLV-1 Cell-to-Cell Transmission

    Directory of Open Access Journals (Sweden)

    Christine Gross

    2016-03-01

    Full Text Available The tumorvirus human T-cell lymphotropic virus type 1 (HTLV-1, a member of the delta-retrovirus family, is transmitted via cell-containing body fluids such as blood products, semen, and breast milk. In vivo, HTLV-1 preferentially infects CD4+ T-cells, and to a lesser extent, CD8+ T-cells, dendritic cells, and monocytes. Efficient infection of CD4+ T-cells requires cell-cell contacts while cell-free virus transmission is inefficient. Two types of cell-cell contacts have been described to be critical for HTLV-1 transmission, tight junctions and cellular conduits. Further, two non-exclusive mechanisms of virus transmission at cell-cell contacts have been proposed: (1 polarized budding of HTLV-1 into synaptic clefts; and (2 cell surface transfer of viral biofilms at virological synapses. In contrast to CD4+ T-cells, dendritic cells can be infected cell-free and, to a greater extent, via viral biofilms in vitro. Cell-to-cell transmission of HTLV-1 requires a coordinated action of steps in the virus infectious cycle with events in the cell-cell adhesion process; therefore, virus propagation from cell-to-cell depends on specific interactions between cellular and viral proteins. Here, we review the molecular mechanisms of HTLV-1 transmission with a focus on the HTLV-1-encoded proteins Tax and p8, their impact on host cell factors mediating cell-cell contacts, cytoskeletal remodeling, and thus, virus propagation.

  2. Cell Culture Made Easy.

    Science.gov (United States)

    Dye, Frank J.

    1985-01-01

    Outlines steps to generate cell samples for observation and experimentation. The procedures (which use ordinary laboratory equipment) will establish a short-term primary culture of normal mammalian cells. Information on culture vessels and cell division and a list of questions to generate student interest and involvement in the topics are…

  3. Mammalian Cell Culture Simplified.

    Science.gov (United States)

    Moss, Robert; Solomon, Sondra

    1991-01-01

    A tissue culture experiment that does not require elaborate equipment and that can be used to teach sterile technique, the principles of animal cell line maintenance, and the concept of cell growth curves is described. The differences between cancerous and normal cells can be highlighted. The procedure is included. (KR)

  4. SYNOVIAL CELL SARCOMA

    OpenAIRE

    Farzan, M

    1997-01-01

    Ten cases of synovial cell sarcoma are reported. The youngest patient was a 2'A years old boy with synovial cell sarcoma of the knee and the oldest one was a man with synovial cell sarcoma of the elbow.

  5. SYNOVIAL CELL SARCOMA

    Directory of Open Access Journals (Sweden)

    M. Farzan

    1997-06-01

    Full Text Available Ten cases of synovial cell sarcoma are reported. The youngest patient was a 2'A years old boy with synovial cell sarcoma of the knee and the oldest one was a man with synovial cell sarcoma of the elbow.

  6. Mast cells and inflammation.

    Science.gov (United States)

    Theoharides, Theoharis C; Alysandratos, Konstantinos-Dionysios; Angelidou, Asimenia; Delivanis, Danae-Anastasia; Sismanopoulos, Nikolaos; Zhang, Bodi; Asadi, Shahrzad; Vasiadi, Magdalini; Weng, Zuyi; Miniati, Alexandra; Kalogeromitros, Dimitrios

    2012-01-01

    Mast cells are well known for their role in allergic and anaphylactic reactions, as well as their involvement in acquired and innate immunity. Increasing evidence now implicates mast cells in inflammatory diseases where they are activated by non-allergic triggers, such as neuropeptides and cytokines, often exerting synergistic effects as in the case of IL-33 and neurotensin. Mast cells can also release pro-inflammatory mediators selectively without degranulation. In particular, IL-1 induces selective release of IL-6, while corticotropin-releasing hormone secreted under stress induces the release of vascular endothelial growth factor. Many inflammatory diseases involve mast cells in cross-talk with T cells, such as atopic dermatitis, psoriasis and multiple sclerosis, which all worsen by stress. How mast cell differential responses are regulated is still unresolved. Preliminary evidence suggests that mitochondrial function and dynamics control mast cell degranulation, but not selective release. Recent findings also indicate that mast cells have immunomodulatory properties. Understanding selective release of mediators could explain how mast cells participate in numerous diverse biologic processes, and how they exert both immunostimulatory and immunosuppressive actions. Unraveling selective mast cell secretion could also help develop unique mast cell inhibitors with novel therapeutic applications. This article is part of a Special Issue entitled: Mast cells in inflammation. PMID:21185371

  7. Mouse Leydig Tumor Cells

    Directory of Open Access Journals (Sweden)

    Bo-Syong Pan

    2011-01-01

    Full Text Available Cordycepin is a natural pure compound extracted from Cordyceps sinensis (CS. We have demonstrated that CS stimulates steroidogenesis in primary mouse Leydig cell and activates apoptosis in MA-10 mouse Leydig tumor cells. It is highly possible that cordycepin is the main component in CS modulating Leydig cell functions. Thus, our aim was to investigate the steroidogenic and apoptotic effects with potential mechanism of cordycepin on MA-10 mouse Leydig tumor cells. Results showed that cordycepin significantly stimulated progesterone production in dose- and time-dependent manners. Adenosine receptor (AR subtype agonists were further used to treat MA-10 cells, showing that A1, A 2A , A 2B , and A3, AR agonists could stimulate progesterone production. However, StAR promoter activity and protein expression remained of no difference among all cordycepin treatments, suggesting that cordycepin might activate AR, but not stimulated StAR protein to regulate MA-10 cell steroidogenesis. Meanwhile, cordycepin could also induce apoptotic cell death in MA-10 cells. Moreover, four AR subtype agonists induced cell death in a dose-dependent manner, and four AR subtype antagonists could all rescue cell death under cordycepin treatment in MA-10 cells. In conclusion, cordycepin could activate adenosine subtype receptors and simultaneously induce steroidogenesis and apoptosis in MA-10 mouse Leydig tumor cells.

  8. Embryonic Stem Cell Markers

    Directory of Open Access Journals (Sweden)

    Lan Ma

    2012-05-01

    Full Text Available Embryonic stem cell (ESC markers are molecules specifically expressed in ES cells. Understanding of the functions of these markers is critical for characterization and elucidation for the mechanism of ESC pluripotent maintenance and self-renewal, therefore helping to accelerate the clinical application of ES cells. Unfortunately, different cell types can share single or sometimes multiple markers; thus the main obstacle in the clinical application of ESC is to purify ES cells from other types of cells, especially tumor cells. Currently, the marker-based flow cytometry (FCM technique and magnetic cell sorting (MACS are the most effective cell isolating methods, and a detailed maker list will help to initially identify, as well as isolate ESCs using these methods. In the current review, we discuss a wide range of cell surface and generic molecular markers that are indicative of the undifferentiated ESCs. Other types of molecules, such as lectins and peptides, which bind to ESC via affinity and specificity, are also summarized. In addition, we review several markers that overlap with tumor stem cells (TSCs, which suggest that uncertainty still exists regarding the benefits of using these markers alone or in various combinations when identifying and isolating cells.

  9. Cell phones and cancer

    Science.gov (United States)

    Cancer and cell phones; Do cell phones cause cancer? ... Several major studies show no link between cell phones and cancer at this time. However, since the information available is based on short-term studies, the impact of many years of ...

  10. Aneuploidy in stem cells

    NARCIS (Netherlands)

    Garcia-Martinez, Jorge; Bakker, Bjorn; Schukken, Klaske M; Simon, Judith E; Foijer, Floris

    2016-01-01

    Stem cells hold enormous promise for regenerative medicine as well as for engineering of model systems to study diseases and develop new drugs. The discovery of protocols that allow for generating induced pluripotent stem cells (IPSCs) from somatic cells has brought this promise steps closer to real

  11. Nanostructured Organic Solar Cells

    DEFF Research Database (Denmark)

    Radziwon, Michal Jędrzej; Rubahn, Horst-Günter; Madsen, Morten

    Recent forecasts for alternative energy generation predict emerging importance of supporting state of art photovoltaic solar cells with their organic equivalents. Despite their significantly lower efficiency, number of application niches are suitable for organic solar cells. This work reveals...... the principles of bulk heterojunction organic solar cells fabrication as well as summarises major differences in physics of their operation....

  12. astrocyte and astrocytoma cells

    DEFF Research Database (Denmark)

    Tfelt-Hansen, J.

    2008-01-01

    -transforming gene (PTTG), was found to be upregulated by the CaR in the H-500 cells, whereas calcium had no effect on PTTG expression in the U-87 astrocytoma cell line, but other proproliferative agents did upregulate PTTG in the U-87 cells. This makes PTTG a potential marker of malignancy and a therapeutic target...

  13. Adventures with Cell Phones

    Science.gov (United States)

    Kolb, Liz

    2011-01-01

    Teachers are finding creative ways to turn the basic cell phone from a digital distraction into a versatile learning tool. In this article, the author explains why cell phones are important in learning and suggests rather than banning them that they be integrated into learning. She presents activities that can be done on a basic cell phone with a…

  14. In vitro study of nanostructured diopside coating on Mg alloy orthopedic implants

    International Nuclear Information System (INIS)

    The high corrosion rate of Mg alloys has hindered their application in various areas, particularly for orthopedic applications. In order to decrease the corrosion rate and to improve the bioactivity, mechanical stability and cytocompatibility of the Mg alloy, nanostructured diopside (CaMgSi2O6) has been coated on AZ91 Mg alloy using a combined micro arc oxidation (MAO) and electrophoretic deposition (EPD) method. The crystalline structure, the morphology and the composition of the samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR). Electrochemical corrosion test, immersion test, and compression test were used to evaluate the corrosion resistance, the in vitro bioactivity and the mechanical stability of the samples, respectively. The cytocompatibility of the samples was tested by the cell viability and the cell attachment of L-929 cells. The results confirmed that the diopside coating not only slows down the corrosion rate, but also enhances the in vitro bioactivity, mechanical stability and cytocompatibility of AZ91 Mg alloy. Therefore, Mg alloy coated with nanostructured diopside offers a promising approach for biodegradable bone implants. - Highlights: • The diopside coating was applied on Mg alloy using the combined MAO and EPD methods. • The corrosion resistance of the diopside coated Mg alloy was noticeably improved. • The in vitro bioactivity of the diopside coated Mg alloy was considerably increased. • The mechanical stability of biodegradable Mg alloy was enhanced by diopside coating. • The cytocompatibility of the Mg alloy was improved employing diopside coating

  15. Introduction to solar cell production

    International Nuclear Information System (INIS)

    This book introduces solar cell production. It is made up eight chapters, which are summary of solar cell with structure and prospect of the business, special variable of solar cell on light of the sun and factor causing variable of solar cell, production of solar cell with surface texturing, diffusion, metal printing dry and firing and edge isolation, process of solar cell on silicone wafer for solar cell, forming of electrodes, introduction of thin film solar cell on operating of solar cell, process of production and high efficiency of thin film solar cell, sorting of solar cell and production with background of silicone solar cell and thin film solar cell, structure and production of thin film solar cell and compound solar cell, introduction of solar cell module and the Industrial condition and prospect of solar cell.

  16. STEM CELLS: Differentiated cells in a back-up role

    OpenAIRE

    Desai, Tushar J.; Krasnow, Mark A.

    2013-01-01

    Two independent studies show that, if push comes to shove, differentiated cells of the stomach and lung can act as adult stem cells generating various cell types of the tissue, including a pool of stem cells.

  17. Induction of Functional Hair-Cell-Like Cells from Mouse Cochlear Multipotent Cells

    OpenAIRE

    Quanwen Liu; Yi Shen; Jiarong Chen; Jie Ding; Zihua Tang; Cui Zhang; Jianling Chen; Liang Li; Ping Chen; Jinfu Wang

    2016-01-01

    In this paper, we developed a two-step-induction method of generating functional hair cells from inner ear multipotent cells. Multipotent cells from the inner ear were established and induced initially into progenitor cells committed to the inner ear cell lineage on the poly-L-lysine substratum. Subsequently, the committed progenitor cells were cultured on the mitotically inactivated chicken utricle stromal cells and induced into hair-cell-like cells containing characteristic stereocilia bund...

  18. Mimicking the inflammatory cell adhesion cascade by nucleic acid aptamer programmed cell-cell interactions

    OpenAIRE

    Zhao, Weian; Loh, Weili; Droujinine, Ilia A.; Teo, Weisuong; Kumar, Namit; Schafer, Sebastian; Cui, Cheryl H.; Zhang, Liang; Sarkar, Debanjan; Karnik, Rohit; Karp, Jeffrey M.

    2011-01-01

    Nature has evolved effective cell adhesion mechanisms to deliver inflammatory cells to inflamed tissue; however, many culture-expanded therapeutic cells are incapable of targeting diseased tissues following systemic infusion, which represents a great challenge in cell therapy. Our aim was to develop simple approaches to program cell-cell interactions that would otherwise not exist toward cell targeting and understanding the complex biology of cell-cell interactions. We employed a chemistry ap...

  19. MAPK uncouples cell cycle progression from cell spreading and cytoskeletal organization in cycling cells

    OpenAIRE

    Margadant, Coert; Cremers, Lobke; Sonnenberg, Arnoud; Boonstra, Johannes

    2012-01-01

    Integrin-mediated cytoskeletal tension supports growth-factor-induced proliferation, and disruption of the actin cytoskeleton in growth factor-stimulated cells prevents the re-expression of cyclin D and cell cycle re-entry from quiescence. In contrast to cells that enter the cell cycle from G0, cycling cells continuously express cyclin D, and are subject to major cell shape changes during the cell cycle. Here, we investigated the cell cycle requirements for cytoskeletal tension and cell sprea...

  20. Transparent ultraviolet photovoltaic cells.

    Science.gov (United States)

    Yang, Xun; Shan, Chong-Xin; Lu, Ying-Jie; Xie, Xiu-Hua; Li, Bing-Hui; Wang, Shuang-Peng; Jiang, Ming-Ming; Shen, De-Zhen

    2016-02-15

    Photovoltaic cells have been fabricated from p-GaN/MgO/n-ZnO structures. The photovoltaic cells are transparent to visible light and can transform ultraviolet irradiation into electrical signals. The efficiency of the photovoltaic cells is 0.025% under simulated AM 1.5 illumination conditions, while it can reach 0.46% under UV illumination. By connecting several such photovoltaic cells in a series, light-emitting devices can be lighting. The photovoltaic cells reported in this Letter may promise the applications in glass of buildings to prevent UV irradiation and produce power for household appliances in the future. PMID:26872163

  1. Fuel Cell/Electrochemical Cell Voltage Monitor

    Science.gov (United States)

    Vasquez, Arturo

    2012-01-01

    A concept has been developed for a new fuel cell individual-cell-voltage monitor that can be directly connected to a multi-cell fuel cell stack for direct substack power provisioning. It can also provide voltage isolation for applications in high-voltage fuel cell stacks. The technology consists of basic modules, each with an 8- to 16-cell input electrical measurement connection port. For each basic module, a power input connection would be provided for direct connection to a sub-stack of fuel cells in series within the larger stack. This power connection would allow for module power to be available in the range of 9-15 volts DC. The relatively low voltage differences that the module would encounter from the input electrical measurement connection port, coupled with the fact that the module's operating power is supplied by the same substack voltage input (and so will be at similar voltage), provides for elimination of high-commonmode voltage issues within each module. Within each module, there would be options for analog-to-digital conversion and data transfer schemes. Each module would also include a data-output/communication port. Each of these ports would be required to be either non-electrical (e.g., optically isolated) or electrically isolated. This is necessary to account for the fact that the plurality of modules attached to the stack will normally be at a range of voltages approaching the full range of the fuel cell stack operating voltages. A communications/ data bus could interface with the several basic modules. Options have been identified for command inputs from the spacecraft vehicle controller, and for output-status/data feeds to the vehicle.

  2. Cell adhesion in regulation of asymmetric stem cell division

    OpenAIRE

    Yamashita, Yukiko M

    2010-01-01

    Adult stem cells inevitably communicate with their cellular neighbors within the tissues they sustain. Indeed, such communication, particularly with components of the stem cell niche, is essential for many aspects of stem cell behavior, including the maintenance of stem cell identity and asymmetric cell division. Cell adhesion mediates this communication by placing stem cells in close proximity to the signaling source and by providing a polarity cue that orients stem cells. Here, I review the...

  3. T cell subpopulations.

    Science.gov (United States)

    Romagnani, Sergio

    2014-01-01

    The role of allergen-specific CD4+ effector type 2 helper (Th2) cells in the pathogenesis of allergic disorders is an established fact. Th2 cells produce interleukin (IL)-4 and IL-13, which induce immunoglobulin E production by B cells, and IL-5 that allows recruitment of eosinophils. Two main mechanisms control the Th2-mediated allergic inflammation: immune deviation (or Th1 redirection) and immune regulation. Regulatory T (Treg) cells exhibit a CD4+ phenotype and include Foxp3-positive thymic and induced Tregs, as well as Foxp3-negative IL-10-producing cells. Both immune deviation and immune regulation evoked by the maternal and newborn microbial environment probably operate in preventing allergen-specific Th2 responses. However, microbe-related protection from allergy seems to mainly depend on epigenetically controlled acetylation of the IFNG promoter of CD4+ T cells. Even Th17 and Th9 cells, as well as invariant NKT cells, have been implicated in the pathogenesis of allergic disorders, but their role is certainly more limited. Recently, innate lymphoid type 2 cells (ILC2) have been found to be able to produce high amounts of IL-5 and IL-13 in response to stimulation with IL-25 and IL-33 produced by non-immune cells. Together with Th2 cells, ILC2 may contribute to the induction and maintenance of allergic inflammation. PMID:24925396

  4. Follicular Helper T Cells.

    Science.gov (United States)

    Vinuesa, Carola G; Linterman, Michelle A; Yu, Di; MacLennan, Ian C M

    2016-05-20

    Although T cell help for B cells was described several decades ago, it was the identification of CXCR5 expression by B follicular helper T (Tfh) cells and the subsequent discovery of their dependence on BCL6 that led to the recognition of Tfh cells as an independent helper subset and accelerated the pace of discovery. More than 20 transcription factors, together with RNA-binding proteins and microRNAs, control the expression of chemotactic receptors and molecules important for the function and homeostasis of Tfh cells. Tfh cells prime B cells to initiate extrafollicular and germinal center antibody responses and are crucial for affinity maturation and maintenance of humoral memory. In addition to the roles that Tfh cells have in antimicrobial defense, in cancer, and as HIV reservoirs, regulation of these cells is critical to prevent autoimmunity. The realization that follicular T cells are heterogeneous, comprising helper and regulatory subsets, has raised questions regarding a possible division of labor in germinal center B cell selection and elimination. PMID:26907215

  5. Parameterization of solar cells

    Science.gov (United States)

    Appelbaum, J.; Chait, A.; Thompson, D.

    1992-10-01

    The aggregation (sorting) of the individual solar cells into an array is commonly based on a single operating point on the current-voltage (I-V) characteristic curve. An alternative approach for cell performance prediction and cell screening is provided by modeling the cell using an equivalent electrical circuit, in which the parameters involved are related to the physical phenomena in the device. These analytical models may be represented by a double exponential I-V characteristic with seven parameters, by a double exponential model with five parameters, or by a single exponential equation with four or five parameters. In this article we address issues concerning methodologies for the determination of solar cell parameters based on measured data points of the I-V characteristic, and introduce a procedure for screening of solar cells for arrays. We show that common curve fitting techniques, e.g., least squares, may produce many combinations of parameter values while maintaining a good fit between the fitted and measured I-V characteristics of the cell. Therefore, techniques relying on curve fitting criteria alone cannot be directly used for cell parameterization. We propose a consistent procedure which takes into account the entire set of parameter values for a batch of cells. This procedure is based on a definition of a mean cell representing the batch, and takes into account the relative contribution of each parameter to the overall goodness of fit. The procedure is demonstrated on a batch of 50 silicon cells for Space Station Freedom.

  6. Cell and Tissue Engineering

    CERN Document Server

    2012-01-01

    Cell and Tissue Engineering” introduces the principles and new approaches in cell and tissue engineering. It includes both the fundamentals and the current trends in cell and tissue engineering, in a way useful both to a novice and an expert in the field. The book is composed of 13 chapters all of which are written by the leading experts. It is organized to gradually assemble an insight in cell and tissue function starting form a molecular nano-level, extending to a cellular micro-level and finishing at the tissue macro-level. In specific, biological, physiological, biophysical, biochemical, medical, and engineering aspects are covered from the standpoint of the development of functional substitutes of biological tissues for potential clinical use. Topics in the area of cell engineering include cell membrane biophysics, structure and function of the cytoskeleton, cell-extracellular matrix interactions, and mechanotransduction. In the area of tissue engineering the focus is on the in vitro cultivation of ...

  7. T Cells Going Innate.

    Science.gov (United States)

    Seyda, Midas; Elkhal, Abdallah; Quante, Markus; Falk, Christine S; Tullius, Stefan G

    2016-08-01

    Natural killer (NK) cell receptors (NKRs) play a crucial role in the homeostasis of antigen-experienced T cells. Indeed, prolonged antigen stimulation may induce changes in the receptor repertoire of T cells to a profile that features NKRs. Chronic antigen exposure, at the same time, has been shown to trigger the loss of costimulatory CD28 molecules with recently reported intensified antigen thresholds of antigen-experienced CD8(+) T cells. In transplantation, NKRs have been shown to assist allograft rejection in a CD28-independent fashion. We discuss here a role for CD28-negative T cells that have acquired the competency of the NKR machinery, potentially promoting allorecognition either through T cell receptor (TCR) crossreactivity or independently from TCR recognition. Collectively, NKRs can bring about innate-like T cells by providing alternative costimulatory pathways that gain relevance in chronic inflammation, potentially leading to resistance to CD28-targeting immunosuppressants. PMID:27402226

  8. Cell sorting apparatus

    Science.gov (United States)

    Yen, Shiao-Ping S. (Inventor); Rembaum, Alan (Inventor); Molday, Robert S. (Inventor)

    1980-01-01

    Polymeric functional microspheres containing metal or metal compounds are formed by addition polymerization of a covalently bondable olefinic monomer such as hydroxyethylmethacrylate in the presence of finely divided metal or metal oxide particles, such as iron, gold, platinum or magnetite, which are embedded in the resulting microspheres. The microspheres can be covalently bonded to chemotherapeutic agents, antibodies, or other proteins providing a means for labeling or separating labeled cells. Labeled cells or microspheres can be concentrated at a specific body location such as in the vicinity of a malignant tumor by applying a magnetic field to the location and then introducing the magnetically attractable microspheres or cells into the circulatory system of the subject. Labeled cells can be separated from a cell mixture by applying a predetermined magnetic field to a tube in which the mixture is flowing. After collection of the labeled cells, the magnetic field is discontinued and the labeled sub-cell population recovered.

  9. Enteroendocrine cell types revisited

    DEFF Research Database (Denmark)

    Engelstoft, Maja S; Egerod, Kristoffer Lihme; Lund, Mari L;

    2013-01-01

    The GI-tract is profoundly involved in the control of metabolism through peptide hormones secreted from enteroendocrine cells scattered throughout the gut mucosa. A large number of recently generated transgenic reporter mice have allowed for direct characterization of biochemical and cell...... biological properties of these previously highly elusive enteroendocrine cells. In particular the surprisingly broad co-expression of six functionally related hormones in the intestinal enteroendocrine cells indicates that it should be possible to control not only the hormone secretion but also the type and...... number of enteroendocrine cells. However, this will require a more deep understanding of the factors controlling differentiation, gene expression and specification of the enteroendocrine cells during their weekly renewal from progenitor cells in the crypts of the mucosa....

  10. Information on Stem Cell Research

    Science.gov (United States)

    ... Enhancing Diversity Find People About NINDS Information on Stem Cell Research Research @ NINDS Stem Cell Highlights Submit a hESC ... found here: Human Induced Pluripotent Stem Cells NINDS Stem Cell Research on Campus The Intramural Research Program of NINDS ...

  11. What Is Giant Cell Arteritis?

    Science.gov (United States)

    ... Uveitis Focus On Pediatric Ophthalmology Education Center Oculofacial Plastic Surgery Center Laser Surgery Education Center Redmond Ethics ... What Is Giant Cell Arteritis? Giant Cell Arteritis Symptoms Who Is At Risk for Giant Cell Arteritis? Giant Cell Arteritis Diagnosis ...

  12. Stages of Renal Cell Cancer

    Science.gov (United States)

    ... cell cancer is a disease in which malignant (cancer) cells form in tubules of the kidney. Renal cell ... diagnosed, tests are done to find out if cancer cells have spread within the kidney or to other ...

  13. Sickle Cell Crisis (Pain Crisis)

    Science.gov (United States)

    ... How Can I Help a Friend Who Cuts? Sickle Cell Crisis (Pain Crisis) KidsHealth > For Teens > Sickle Cell ... A A A Text Size What Is a Sickle Cell Crisis? Sickle cell disease changes the shape of ...

  14. Nevoid Basal Cell Carcinoma Syndrome

    Science.gov (United States)

    ... Nevoid Basal Cell Carcinoma Syndrome Request Permissions Nevoid Basal Cell Carcinoma Syndrome Approved by the Cancer.Net Editorial Board , 04/2016 What is Nevoid Basal Cell Carcinoma Syndrome? Nevoid Basal Cell Carcinoma Syndrome (NBCCS) is ...

  15. Nestin(+) cells direct inflammatory cell migration in atherosclerosis.

    Science.gov (United States)

    Del Toro, Raquel; Chèvre, Raphael; Rodríguez, Cristina; Ordóñez, Antonio; Martínez-González, José; Andrés, Vicente; Méndez-Ferrer, Simón

    2016-01-01

    Atherosclerosis is a leading death cause. Endothelial and smooth muscle cells participate in atherogenesis, but it is unclear whether other mesenchymal cells contribute to this process. Bone marrow (BM) nestin(+) cells cooperate with endothelial cells in directing monocyte egress to bloodstream in response to infections. However, it remains unknown whether nestin(+) cells regulate inflammatory cells in chronic inflammatory diseases, such as atherosclerosis. Here, we show that nestin(+) cells direct inflammatory cell migration during chronic inflammation. In Apolipoprotein E (ApoE) knockout mice fed with high-fat diet, BM nestin(+) cells regulate the egress of inflammatory monocytes and neutrophils. In the aorta, nestin(+) stromal cells increase ∼30 times and contribute to the atheroma plaque. Mcp1 deletion in nestin(+) cells-but not in endothelial cells only- increases circulating inflammatory cells, but decreases their aortic infiltration, delaying atheroma plaque formation and aortic valve calcification. Therefore, nestin expression marks cells that regulate inflammatory cell migration during atherosclerosis. PMID:27586429

  16. Introduction to Stem Cell Therapy

    OpenAIRE

    Biehl, Jesse K.; Russell, Brenda

    2009-01-01

    Stem cells have the ability to differentiate into specific cell types. The two defining characteristics of a stem cell are perpetual self-renewal and the ability to differentiate into a specialized adult cell type. There are two major classes of stem cells: pluripotent that can become any cell in the adult body, and multipotent that are restricted to becoming a more limited population of cells. Cell sources, characteristics, differentiation and therapeutic applications are discussed. Stem cel...

  17. PEROVSKITE SOLAR CELLS (REVIEW ARTICLE)

    OpenAIRE

    Benli, Deniz Ahmet

    2015-01-01

    A solar cell is a device that converts sunlight into electricity. There are different types of solar cells but this report mainly focuses on a type of new generation solar cell that has the name organo-metal halide perovskite, shortly perovskite solar cells. In this respect, the efficiency of power conversion is taken into account to replace the dominancy of traditional and second generation solar cell fields by perovskite solar cells. Perovskite solar cell is a type of solar cell including a...

  18. Adult retinal stem cells revisited.

    OpenAIRE

    Bhatia, B; Singhal, S; Jayaram, H.; Khaw, P T; Limb, G A

    2010-01-01

    Recent advances in retinal stem cell research have raised the possibility that these cells have the potential to be used to repair or regenerate diseased retina. Various cell sources for replacement of retinal neurons have been identified, including embryonic stem cells, the adult ciliary epithelium, adult Müller stem cells and induced pluripotent stem cells (iPS). However, the true stem cell nature of the ciliary epithelium and its possible application in cell therapies has now been question...

  19. Simple Cell Balance Circuit

    Science.gov (United States)

    Johnson, Steven D.; Byers, Jerry W.; Martin, James A.

    2012-01-01

    A method has been developed for continuous cell voltage balancing for rechargeable batteries (e.g. lithium ion batteries). A resistor divider chain is provided that generates a set of voltages representing the ideal cell voltage (the voltage of each cell should be as if the cells were perfectly balanced). An operational amplifier circuit with an added current buffer stage generates the ideal voltage with a very high degree of accuracy, using the concept of negative feedback. The ideal voltages are each connected to the corresponding cell through a current- limiting resistance. Over time, having the cell connected to the ideal voltage provides a balancing current that moves the cell voltage very close to that ideal level. In effect, it adjusts the current of each cell during charging, discharging, and standby periods to force the cell voltages to be equal to the ideal voltages generated by the resistor divider. The device also includes solid-state switches that disconnect the circuit from the battery so that it will not discharge the battery during storage. This solution requires relatively few parts and is, therefore, of lower cost and of increased reliability due to the fewer failure modes. Additionally, this design uses very little power. A preliminary model predicts a power usage of 0.18 W for an 8-cell battery. This approach is applicable to a wide range of battery capacities and voltages.

  20. T follicular regulatory cells.

    Science.gov (United States)

    Sage, Peter T; Sharpe, Arlene H

    2016-05-01

    Pathogen exposure elicits production of high-affinity antibodies stimulated by T follicular helper (Tfh) cells in the germinal center reaction. Tfh cells provide both costimulation and stimulatory cytokines to B cells to facilitate affinity maturation, class switch recombination, and plasma cell differentiation within the germinal center. Under normal circumstances, the germinal center reaction results in antibodies that precisely target foreign pathogens while limiting autoimmunity and excessive inflammation. In order to have this degree of control, the immune system ensures Tfh-mediated B-cell help is regulated locally in the germinal center. The recently identified T follicular regulatory (Tfr) cell subset can migrate to the germinal center and inhibit Tfh-mediated B-cell activation and antibody production. Although many aspects of Tfr cell biology are still unclear, recent data have begun to delineate the specialized roles of Tfr cells in controlling the germinal center reaction. Here we discuss the current understanding of Tfr-cell differentiation and function and how this knowledge is providing new insights into the dynamic regulation of germinal centers, and suggesting more efficacious vaccine strategies and ways to treat antibody-mediated diseases. PMID:27088919

  1. Brain tumor stem cells.

    Science.gov (United States)

    Palm, Thomas; Schwamborn, Jens C

    2010-06-01

    Since the end of the 'no-new-neuron' theory, emerging evidence from multiple studies has supported the existence of stem cells in neurogenic areas of the adult brain. Along with this discovery, neural stem cells became candidate cells being at the origin of brain tumors. In fact, it has been demonstrated that molecular mechanisms controlling self-renewal and differentiation are shared between brain tumor stem cells and neural stem cells and that corruption of genes implicated in these pathways can direct tumor growth. In this regard, future anticancer approaches could be inspired by uncovering such redundancies and setting up treatments leading to exhaustion of the cancer stem cell pool. However, deleterious effects on (normal) neural stem cells should be minimized. Such therapeutic models underline the importance to study the cellular mechanisms implicated in fate decisions of neural stem cells and the oncogenic derivation of adult brain cells. In this review, we discuss the putative origins of brain tumor stem cells and their possible implications on future therapies. PMID:20370314

  2. B cells help alloreactive T cells differentiate into memory T cells1

    OpenAIRE

    Ng, Yue-Harn; Oberbarnscheidt, Martin H.; Chandramoorthy, Harish Chinna Konda; Hoffman, Rosemary; Chalasani, Geetha

    2010-01-01

    B cells are recognized as effector cells in allograft rejection that are dependent upon T cell help to produce alloantibodies causing graft injury. It is not known if B cells can also help T cells differentiate into memory cells in the alloimmune response. We found that in B cell-deficient hosts, differentiation of alloreactive T cells into effectors was intact whereas their development into memory T cells was impaired. To test if B cell help for T cells was required for their continued diffe...

  3. Determining Cell Number During Cell Culture using the Scepter Cell Counter

    OpenAIRE

    Ongena, Kathleen; Das, Chandreyee; Smith, Janet L.; Gil, Sónia; Johnston, Grace

    2010-01-01

    Counting cells is often a necessary but tedious step for in vitro cell culture. Consistent cell concentrations ensure experimental reproducibility and accuracy. Cell counts are important for monitoring cell health and proliferation rate, assessing immortalization or transformation, seeding cells for subsequent experiments, transfection or infection, and preparing for cell-based assays. It is important that cell counts be accurate, consistent, and fast, particularly for quantitative measuremen...

  4. Basal cell carcinoma of the skin with areas of squamous cell carcinoma: a basosquamous cell carcinoma?

    OpenAIRE

    Faria, J.

    1985-01-01

    The diagnosis of basosquamous cell carcinoma is controversial. A review of cases of basal cell carcinoma showed 23 cases that had conspicuous areas of squamous cell carcinoma. This was distinguished from squamous differentiation and keratotic basal cell carcinoma by a comparative study of 40 cases of compact lobular and 40 cases of keratotic basal cell carcinoma. Areas of intermediate tumour differentiation between basal cell and squamous cell carcinoma were found. Basal cell carcinomas with ...

  5. Induced pluripotent stem cells

    Institute of Scientific and Technical Information of China (English)

    Siddhartha Bhowmik; LI Yong

    2011-01-01

    Induced pluripotent stem (iPS) cells are a recent development which has brought a promise of great therapeutic values. The previous technique of somatic cell nuclear transfer (SCNT) has been ineffective in humans. Recent discoveries show that human fibroblasts can be reprogrammed by a transient over expression of a small number of genes; they can undergo induced pluripotency. iPS were first produced in 2006. By 2008, work was underway to remove the potential oncogenes from their structure. In 2009, protein iPS (piPS) cells were discovered. Surface markers and reporter genes play an important role in stem cell research. Clinical applications include generation of self renewing stem cells, tissue replacement and many more. Stem cell therapy has the ability to dramatically change the treatment of human diseases.

  6. Cytoskeleton and Cell Motility

    CERN Document Server

    Risler, Thomas

    2011-01-01

    The present article is an invited contribution to the Encyclopedia of Complexity and System Science, Robert A. Meyers Ed., Springer New York (2009). It is a review of the biophysical mechanisms that underly cell motility. It mainly focuses on the eukaryotic cytoskeleton and cell-motility mechanisms. Bacterial motility as well as the composition of the prokaryotic cytoskeleton is only briefly mentioned. The article is organized as follows. In Section III, I first present an overview of the diversity of cellular motility mechanisms, which might at first glance be categorized into two different types of behaviors, namely "swimming" and "crawling". Intracellular transport, mitosis - or cell division - as well as other extensions of cell motility that rely on the same essential machinery are briefly sketched. In Section IV, I introduce the molecular machinery that underlies cell motility - the cytoskeleton - as well as its interactions with the external environment of the cell and its main regulatory pathways. Sec...

  7. Cell transformation and mutagenesis

    International Nuclear Information System (INIS)

    This chapter summarizes the studies of the dose-effect relationships of cell transformation and of mutation for heavy ions with various charges, velocities and LET values. In cell transformation studies, carbon particles consistently gave a higher frequency of transformation per viable cell than x rays. For the same cell line, the RBE is about the same for both cell killings and oncogenic transformation for a given quality of ionizing radiation. In cocarcinogenesis studies, neon irradiation showed an enhancement effect on the viral transformation of cells. To explain the enhanced transformation, it has been suggested that radiation produces strand breaks in cellular DNA that promote the attachment of viral genomes during DNA repair synthesis. In mutagenesis studies, high-LET heavy ions could not effectively induce ouabain resistant mutations

  8. Mammalian cell biology

    International Nuclear Information System (INIS)

    Studies of the action of N-ethylmaleimide (NEM), as an inhibitor of repair of x radioinduced injuries were extended from synchronous Chinese hamster cells to synchronous human HeLa cells. These studies showed a similar mode of action in both cell types lending support to the notion that conclusions may be extracted from such observations that are of fairly general applicability to mammalian cells. Radiation studies with NEM are being extended to hypoxic cells to inquire if NEM is effective relative to oxygen-independent damage. Observations relative to survival, DNA synthesis, and DNA strand elongation resulting from the addition products to DNA when cells were exposed to near uv in the presence of psoralen were extended. (U.S.)

  9. Concentrator silicon cell research

    Energy Technology Data Exchange (ETDEWEB)

    Green, M.A.; Wenham, S.R.; Zhang, F.; Zhao, J.; Wang, A. [New South Wales Univ., Kensington (Australia). Solar Photovoltaic Lab.

    1992-04-01

    This project continued the developments of high-efficiency silicon concentrator solar cells with the goal of achieving a cell efficiency in the 26 to 27 percent range at a concentration level of 150 suns of greater. The target efficiency was achieved with the new PERL (passivated emitter, rear locally diffused) cell structure, but only at low concentration levels around 20 suns. The PERL structure combines oxide passivation of both top and rear surfaces of the cells with small area contact to heavily doped regions on the top and rear surfaces. Efficiency in the 22 to 23 percent range was also demonstrated for large-area concentrator cells fabricated with the buried contact solar cell processing sequence, either when combined with prismatic covers or with other innovative approaches to reduce top contact shadowing. 19 refs.

  10. Fish germ cells

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Fish, like many other animals, have two major cell lineages, namely the germline and soma. The germ-soma separation is one of the earliest events of embryonic development. Germ cells can be specifically labeled and isolated for culture and transplan-tation, providing tools for reproduction of endangered species in close relatives, such as surrogate production of trout in salmon. Haploid cell cultures, such as medaka haploid embryonic stem cells have recently been obtained, which are capable of mimicking sperm to produce fertile offspring, upon nuclear being directly transferred into normal eggs. Such fish originated from a mosaic oocyte that had a haploid meiotic nucleus and a transplanted haploid mitotic cell culture nucleus. The first semi-cloned fish is Holly. Here we review the current status and future directions of understanding and manipulating fish germ cells in basic research and reproductive technology.

  11. NCAM regulates cell motility

    DEFF Research Database (Denmark)

    Prag, Søren; Lepekhin, Eugene A; Kolkova, Kateryna;

    2002-01-01

    Cell migration is required during development of the nervous system. The regulatory mechanisms for this process, however, are poorly elucidated. We show here that expression of or exposure to the neural cell adhesion molecule (NCAM) strongly affected the motile behaviour of glioma cells...... independently of homophilic NCAM interactions. Expression of the transmembrane 140 kDa isoform of NCAM (NCAM-140) caused a significant reduction in cellular motility, probably through interference with factors regulating cellular attachment, as NCAM-140-expressing cells exhibited a decreased attachment to a...... fibronectin substratum compared with NCAM-negative cells. Ectopic expression of the cytoplasmic part of NCAM-140 also inhibited cell motility, presumably via the non-receptor tyrosine kinase p59(fyn) with which NCAM-140 interacts. Furthermore, we showed that the extracellular part of NCAM acted as a paracrine...

  12. Traction in smooth muscle cells varies with cell spreading

    Science.gov (United States)

    Tolic-Norrelykke, Iva Marija; Wang, Ning

    2005-01-01

    Changes in cell shape regulate cell growth, differentiation, and apoptosis. It has been suggested that the regulation of cell function by the cell shape is a result of the tension in the cytoskeleton and the distortion of the cell. Here we explore the association between cell-generated mechanical forces and the cell morphology. We hypothesized that the cell contractile force is associated with the degree of cell spreading, in particular with the cell length. We measured traction fields of single human airway smooth muscle cells plated on a polyacrylamide gel, in which fluorescent microbeads were embedded to serve as markers of gel deformation. The traction exerted by the cells at the cell-substrate interface was determined from the measured deformation of the gel. The traction was measured before and after treatment with the contractile agonist histamine, or the relaxing agonist isoproterenol. The relative increase in traction induced by histamine was negatively correlated with the baseline traction. On the contrary, the relative decrease in traction due to isoproterenol was independent of the baseline traction, but it was associated with cell shape: traction decreased more in elongated than in round cells. Maximum cell width, mean cell width, and projected area of the cell were the parameters most tightly coupled to both baseline and histamine-induced traction in this study. Wide and well-spread cells exerted larger traction than slim cells. These results suggest that cell contractility is controlled by cell spreading.

  13. Direct hydrocarbon fuel cells

    Science.gov (United States)

    Barnett, Scott A.; Lai, Tammy; Liu, Jiang

    2010-05-04

    The direct electrochemical oxidation of hydrocarbons in solid oxide fuel cells, to generate greater power densities at lower temperatures without carbon deposition. The performance obtained is comparable to that of fuel cells used for hydrogen, and is achieved by using novel anode composites at low operating temperatures. Such solid oxide fuel cells, regardless of fuel source or operation, can be configured advantageously using the structural geometries of this invention.

  14. Microbial fuel cells

    International Nuclear Information System (INIS)

    Microbial fuel cells (MFC) are a promising technology for sustainable production of alternative energy and waste treatment. A microbial fuel cell transformation chemical energy in the chemical bonds in organic compounds to electrical energy through catalytic reactions of microorganisms under anaerobic conditions. It has been known for many years that it is possible to generate electricity directly by using bacteria to break down organic substrates. Key words: microbial fuel cells (MFC), biosensor, wastewater treatment

  15. Cancer Stem Cells

    OpenAIRE

    Aurelio Lorico; Eric Deutsch; Bo Lu; Shih-Hwa Chiou

    2011-01-01

    Cancer Stem Cells (CSCs) are a small subpopulation of cells within tumors with capabilities of self-renewal, differentiation, and tumorigenicity when transplanted into an animal host. A number of cell surface markers such as CD44, CD24, and CD133 are often used to identify and enrich CSCs. A regulatory network consisting of microRNAs and Wnt/β-catenin, Notch, and Hedgehog signaling pathways controls the CSC properties. The clinical relevance of CSCs has been strengthened by emerging evidence,...

  16. Gastric Cancer Stem Cells

    OpenAIRE

    Takaishi, Shigeo; Okumura, Tomoyuki; Timothy C Wang

    2008-01-01

    Cancer stem cells are defined as the unique subpopulation in the tumors that possess the ability to initiate tumor growth and sustain self-renewal as well as metastatic potential. Accumulating evidence in recent years strongly indicate the existence of cancer stem cells in solid tumors of a wide variety of organs. In this review, we will discuss the possible existence of a gastric cancer stem cell. Our recent data suggest that a subpopulation with a defined marker shows spheroid colony format...

  17. Turing Patterns Inside Cells

    OpenAIRE

    Strier, Damián E.; Ponce Dawson, Silvina

    2007-01-01

    Concentration gradients inside cells are involved in key processes such as cell division and morphogenesis. Here we show that a model of the enzymatic step catalized by phosphofructokinase (PFK), a step which is responsible for the appearance of homogeneous oscillations in the glycolytic pathway, displays Turing patterns with an intrinsic length-scale that is smaller than a typical cell size. All the parameter values are fully consistent with classic experiments on glycolytic oscillations and...

  18. Mammary epithelial cell

    DEFF Research Database (Denmark)

    Kass, Laura; Erler, Janine Terra; Dembo, Micah;

    2007-01-01

    mammary gland. During breast development and cancer progression, the extracellular matrix is dynamically altered such that its composition, turnover, processing and orientation change dramatically. These modifications influence mammary epithelial cell shape, and modulate growth factor and hormonal...... organization, and promote cell invasion and survival. In this review, we discuss the role of stromal-epithelial interactions in normal and malignant mammary epithelial cell behavior. We specifically focus on how dynamic modulation of the biochemical and biophysical properties of the extracellular matrix elicit...

  19. Chiaroscuro hematopoietic stem cell.

    OpenAIRE

    Quesenberry, P.; Habibian, M. (PhD); Dooner, M; Zhong, S.; Reilly, J; Peters, S.; De Becker, P; Grimaldi, C.; Carlson, J; REDDY, P; Nilsson, S.; Stewart, F. M.

    1998-01-01

    These observations suggest several immediate clinical strategies. In gene therapy, approaches could be targeted to obtain cycling of hematopoietic stem cells and gene-carrying retrovirus vector integration followed by engraftment at an appropriate time interval which favors engraftment. The same type of approach can be utilized for stem cell expansion approaches. Alternatively marrow or peripheral stem cell engraftment can be obtained with minimal to no toxicity in allochimeric strategies in ...

  20. Stem cell myths

    OpenAIRE

    Magnus, Tim; Liu, Ying; Parker, Graham C.; Rao, Mahendra S.

    2007-01-01

    Stem cells, although difficult to define, hold great promise as tools for understanding development and as therapeutic agents. However, as with any new field, uncritical enthusiasm can outstrip reality. In this review, we have listed nine common myths that we believe affect our approach to evaluating stem cells for therapy. We suggest that careful consideration needs to be given to each of these issues when evaluating a particular cell for its use in therapy. Data need to be collected and rep...

  1. Cancer stem cell metabolism

    OpenAIRE

    Peiris-Pagès, Maria; Martinez-Outschoorn, Ubaldo E.; Pestell, Richard G.; Sotgia, Federica; Lisanti, Michael P

    2016-01-01

    Cancer is now viewed as a stem cell disease. There is still no consensus on the metabolic characteristics of cancer stem cells, with several studies indicating that they are mainly glycolytic and others pointing instead to mitochondrial metabolism as their principal source of energy. Cancer stem cells also seem to adapt their metabolism to microenvironmental changes by conveniently shifting energy production from one pathway to another, or by acquiring intermediate metabolic phenotypes. Deter...

  2. Lung Stem cell biology

    OpenAIRE

    Ardhanareeswaran, Karthikeyan; Mirotsou, Maria

    2013-01-01

    Over the past few years new insights have been added to the study of stem cells in the adult lung. The exploration of the endogenous lung progenitors as well as the study of exogenously delivered stem cell populations holds promise for advancing our understanding of the biology of lung repair mechanisms. Moreover, it opens new possibilities for the use of stem cell therapy for the development of regenerative medicine approaches for the treatment of lung disease. Here, we discuss the main type...

  3. Control of Fuel Cells

    OpenAIRE

    ZENITH, Federico

    2007-01-01

    This thesis deals with control of fuel cells, focusing on high-temperature proton-exchange-membrane fuel cells. Fuel cells are devices that convert the chemical energy of hydrogen, methanol or other chemical compounds directly into electricity, without combustion or thermal cycles. They are efficient, scalable and silent devices that can provide power to a wide variety of utilities, from portable electronics to vehicles, to nation-wide electric grids. Whereas studies about the design of fuel ...

  4. Control of Fuel Cells

    OpenAIRE

    ZENITH, Federico

    2007-01-01

    This thesis deals with control of fuel cells, focusing on high-temperature proton-exchange-membrane fuel cells.Fuel cells are devices that convert the chemical energy of hydrogen, methanol or other chemical compounds directly into electricity, without combustion or thermal cycles. They are efficient, scalable and silent devices that can provide power to a wide variety of utilities, from portable electronics to vehicles, to nation-wide electric grids.Whereas studies about the design of fuel ce...

  5. Epidermal Stem Cells

    OpenAIRE

    Osman Köse

    2015-01-01

    The epidermis is the outermost layer of the human skin and comprises a multilayered epithelium, the interfollicular epidermis, with associated hair follicles, sebaceous glands, and eccrine sweat glands. There are many origins of stem cells in the skin and skin appendages. These stem cells are localized in different part of the pilosebaseous units and also express many different genes. Epidermal stem cells in the pilosebaseous units not only ensure the maintenance of epidermal homeostasis and ...

  6. Liver Cancer Stem Cells

    OpenAIRE

    Sameh Mikhail; Aiwu Ruth He

    2011-01-01

    Hepatocellular carcinoma is the most common primary malignancy of the liver in adults. It is also the fifth most common solid cancer worldwide and the third leading cause of cancer-related death. Recent research supports that liver cancer is a disease of adult stem cells. From the models of experimental hepatocarcinogenesis, there may be at least three distinct cell lineages with progenitor properties susceptible to neoplastic transformation. Identification of specific cell surface markers fo...

  7. Cell therapy of pseudarthrosis

    OpenAIRE

    Bastos Filho, Ricardo; Lermontov, Simone; Borojevic, Radovan; Schott, Paulo Cezar; Gameiro, Vinicius Schott; José Mauro GRANJEIRO

    2012-01-01

    Objective To assess the safety and efficiency of cell therapy for pseudarthrosis. Implant of the bone marrow aspirate was compared to mononuclear cells purified extemporaneously using the Sepax® equipment. Methods Six patients with nonunion of the tibia or femur were treated. Four received a percutaneous infusion of autologous bone marrow aspirated from the iliac crest, and two received autologous bone marrow mononuclear cells separated from the aspirate with the Sepax®. The primary fixation ...

  8. Hair cell ribbon synapses

    OpenAIRE

    Moser, Tobias; Brandt, Andreas; Lysakowski, Anna

    2006-01-01

    Hearing and balance rely on the faithful synaptic coding of mechanical input by the auditory and vestibular hair cells of the inner ear. Mechanical deflection of their stereocilia causes the opening of mechanosensitive channels, resulting in hair cell depolarization, which controls the release of glutamate at ribbon-type synapses. Hair cells have a compact shape with strong polarity. Mechanoelectrical transduction and active membrane turnover associated with stereociliar renewal dominate the ...

  9. Plasma cell gingivitis

    OpenAIRE

    Chandershekhar Joshi; Pradeep Shukla

    2015-01-01

    The aim of the article is to present a report on the clinical presentation of plasma cell gingivitis with the use of herbal toothpowder. Plasma cell gingivitis [PCG] is a rare benign condition of the gingiva characterized by sharply demarcated erythematous and edematous gingivitis often extending to the mucogingival junction. As the name suggests it is diffuse and massive infiltration of plasma cells into the sub-epithelial gingival tissue. It is a hypersensitivity reaction to some antigen, o...

  10. APUD cells in teratomas.

    OpenAIRE

    Bosman, F. T.; Louwerens, J. W.

    1981-01-01

    The origin of the endocrine cells in the respiratory tract and the gastrointestinal tract is still a matter of debate. In the original concept of the amine precursor uptake and decarboxylation (APUD) system, all APUD cells were considered to be derived from the neural crest. More recently it has been proposed that the APUD cell types of the gastrointestinal and respiratory tracts originate from neuroendocrine-programmed ectoblast. Still other investigators have reported observations that favo...

  11. Mesenchymal stem cells.

    Science.gov (United States)

    Ding, Dah-Ching; Shyu, Woei-Cherng; Lin, Shinn-Zong

    2011-01-01

    Stem cells have two features: the ability to differentiate along different lineages and the ability of self-renewal. Two major types of stem cells have been described, namely, embryonic stem cells and adult stem cells. Embryonic stem cells (ESC) are obtained from the inner cell mass of the blastocyst and are associated with tumorigenesis, and the use of human ESCs involves ethical and legal considerations. The use of adult mesenchymal stem cells is less problematic with regard to these issues. Mesenchymal stem cells (MSCs) are stromal cells that have the ability to self-renew and also exhibit multilineage differentiation. MSCs can be isolated from a variety of tissues, such as umbilical cord, endometrial polyps, menses blood, bone marrow, adipose tissue, etc. This is because the ease of harvest and quantity obtained make these sources most practical for experimental and possible clinical applications. Recently, MSCs have been found in new sources, such as menstrual blood and endometrium. There are likely more sources of MSCs waiting to be discovered, and MSCs may be a good candidate for future experimental or clinical applications. One of the major challenges is to elucidate the mechanisms of differentiation, mobilization, and homing of MSCs, which are highly complex. The multipotent properties of MSCs make them an attractive choice for possible development of clinical applications. Future studies should explore the role of MSCs in differentiation, transplantation, and immune response in various diseases. PMID:21396235

  12. Littoral Cells 2005

    Data.gov (United States)

    California Department of Resources — Littoral cells along the California Coast. Originally digitized by Melanie Coyne from the Assessment and Atlas of Shoreline Erosion Along the California Coast...

  13. Sarcomatoid renal cell carcinoma

    OpenAIRE

    Kafil Akhtar; Ahmad Shamshad; Zaheer Sufian; Mansoor Tariq

    2011-01-01

    Sarcomatoid renal cell carcinoma (SRCC) is an aggressive tumor variant thought to arise predominantly from differentiation of clear cell carcinoma. A few reports of SRCC asso-ciated with non-clear cell tumors led to the presumption that SRCC may arise from any renal cell carcinoma, although direct evidence of this is lacking. We report a case of a 70-year-old male patient, who presented with acute left upper quadrant abdominal pain and was diagnosed to have SRCC after pathological examination...

  14. Adenoviral Producer Cells

    Directory of Open Access Journals (Sweden)

    Imre Kovesdi

    2010-08-01

    Full Text Available Adenovirus (Ad vectors, in particular those of the serotype 5, are highly attractive for a wide range of gene therapy, vaccine and virotherapy applications (as discussed in further detail in this issue. Wild type Ad5 virus can replicate in numerous tissue types but to use Ad vectors for therapeutic purposes the viral genome requires modification. In particular, if the viral genome is modified in such a way that the viral life cycle is interfered with, a specific producer cell line is required to provide trans-complementation to overcome the modification and allow viral production. This can occur in two ways; use of a producer cell line that contains specific adenoviral sequences incorporated into the cell genome to trans-complement, or use of a producer cell line that naturally complements for the modified Ad vector genome. This review concentrates on producer cell lines that complement non-replicating adenoviral vectors, starting with the historical HEK293 cell line developed in 1977 for first generation Ad vectors. In addition the problem of replication-competent adenovirus (RCA contamination in viral preparations from HEK293 cells is addressed leading to the development of alternate cell lines. Furthermore novel cell lines for more complex Ad vectors and alternate serotype Ad vectors are discussed.

  15. Radioresistance of dendritic cells

    International Nuclear Information System (INIS)

    To evaluate radiation sensitivity of dendritic cells in comparison with lymphocytes. T lymphocytes captured from peripheral blood were irradiated by 0 Gy, 10 Gy, 30 Gy. Apoptosis was measured by flowcytometry for staining of annexin V 4 hours after irradiation. Immature and mature dendritic cells processed from blood hematopoietic stem cell were irradiated by 0 Gy, 10 Gy, 30 Gy, 100 Gy respectively and apoptosis was measured by flowcytometry with time differences as 4h, 24h and 48h after irradiation. Morphometric analysis by percent nucleus was measured in three cell groups, also. Lymphocytes showed radiation sensitivity by increasing apoptotic fraction according to radiation dose. However, both mature and immature dendritic cells showed consistent fraction of apoptosis in spite of increasing radiation dose. Percent nucleus ratio is significantly higher in lymphocytes than that of mature or immature dendritic cells. Stimulation of T-cell by dendritic cells was not changed after irradiation. Dendritic cells showed radioresistance which was associated with small size of nucleus in comparison with lymphocytes and this result would be used as a basal data of radio-labelling for the cellular trafficking studies in nuclear medicine fields

  16. Nanocrystal Solar Cells

    Energy Technology Data Exchange (ETDEWEB)

    Gur, Ilan

    2006-12-15

    This dissertation presents the results of a research agenda aimed at improving integration and stability in nanocrystal-based solar cells through advances in active materials and device architectures. The introduction of 3-dimensional nanocrystals illustrates the potential for improving transport and percolation in hybrid solar cells and enables novel fabrication methods for optimizing integration in these systems. Fabricating cells by sequential deposition allows for solution-based assembly of hybrid composites with controlled and well-characterized dispersion and electrode contact. Hyperbranched nanocrystals emerge as a nearly ideal building block for hybrid cells, allowing the controlled morphologies targeted by templated approaches to be achieved in an easily fabricated solution-cast device. In addition to offering practical benefits to device processing, these approaches offer fundamental insight into the operation of hybrid solar cells, shedding light on key phenomena such as the roles of electrode-contact and percolation behavior in these cells. Finally, all-inorganic nanocrystal solar cells are presented as a wholly new cell concept, illustrating that donor-acceptor charge transfer and directed carrier diffusion can be utilized in a system with no organic components, and that nanocrystals may act as building blocks for efficient, stable, and low-cost thin-film solar cells.

  17. T-cell costimulation

    DEFF Research Database (Denmark)

    Owens, T

    1996-01-01

    The CD40L molecule expressed by CD4+ regulatory T lymphocytes is known to deliver signals that activate B cells and macrophages. It now appears that CD40L regulates T cells themselves, during both their development and their participation in adaptive immune responses.......The CD40L molecule expressed by CD4+ regulatory T lymphocytes is known to deliver signals that activate B cells and macrophages. It now appears that CD40L regulates T cells themselves, during both their development and their participation in adaptive immune responses....

  18. Live-cell luciferase assay of drug resistant cells

    OpenAIRE

    sprotocols

    2015-01-01

    To date, multiplexing cell-based assay is essential for high-throughput screening of molecular targets. Measuring multiple parameters of a single sample increases consistency and decrease time and cost of assay. Functional assay of living cell is useful as a first step of multiplexing assay, because live-cell assay allows following second assay using cell lysate or stained cell. However, live-cell assay of drug resistant cells that are highly activated of drug efflux mechanisms is sometimes u...

  19. Stem cells - biological update and cell therapy progress

    OpenAIRE

    GIRLOVANU, MIHAI; Susman, Sergiu; Soritau, Olga; RUS-CIUCA, DAN; MELINCOVICI, CARMEN; CONSTANTIN, ANNE-MARIE; Carmen Mihaela MIHU

    2015-01-01

    In recent years, the advances in stem cell research have suggested that the human body may have a higher plasticity than it was originally expected. Until now, four categories of stem cells were isolated and cultured in vivo: embryonic stem cells, fetal stem cells, adult stem cells and induced pluripotent stem cells (hiPSCs). Although multiple studies were published, several issues concerning the stem cells are still debated, such as: the molecular mechanisms of differentiation, the methods t...

  20. A focus on parietal cells as a renewing cell population

    Institute of Scientific and Technical Information of China (English)

    Sherif; M; Karam

    2010-01-01

    The fact that the acidsecreting parietal cells undergo continuous renewal has been ignored by many gastroenterologists and cell biologists. In the past, it was thought that these cells were static. However, by using 3Hthymidine radioautography in combination with electron microscopy, it was possible to demonstrate that parietal cells belong to a continuously renewing epithelial cell lineage. In the gastric glands, stem cells anchored in the isthmus region are responsible for the production of parietal cells...