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Sample records for cell seeded hydrogel

  1. Fabrication of polycaprolactone collagen hydrogel constructs seeded with mesenchymal stem cells for bone regeneration

    Energy Technology Data Exchange (ETDEWEB)

    Reichert, J C; Berner, A [Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane (Australia); Heymer, A; Eulert, J; Noeth, U, E-mail: johannes.reichert@qut.edu.a [Orthopaedic Institute, Division of Tissue Engineering, Koenig-Ludwig-Haus, Julius-Maximilians-University, Wuerzburg (Germany)

    2009-12-15

    The osteogenic differentiation of bone marrow-derived human mesenchymal stem cells (MSCs) in a collagen I hydrogel was investigated. Collagen hydrogels with 7.5 x 10{sup 5} MSCs ml{sup -1} were fabricated and cultured for 6 weeks in a defined, osteogenic differentiation medium. Histochemistry revealed morphologically distinct, chondrocyte-like cells, surrounded by a sulfated proteoglycan-rich extracellular matrix in the group treated with bone morphogenetic protein 2 (BMP-2), while cells cultured with dexamethasone, ascorbate-2-phosphate, and beta-glycerophosphate displayed a spindle-shaped morphology and deposited a mineralized matrix. Real-time polymerase chain reaction (RT-PCR) analyses revealed a specific chondrogenic differentiation with the expression of cartilage-specific markers in the BMP-2-treated group and a distinct expression pattern of the osteogenic markers alkaline phosphatase (ALP), type I collagen, osteocalcin (OC), and cbfa-1 in the group treated with an osteogenic standard medium. The collagen gels were used to engineer a cell laden medical grade epsilon-polycaprolactone (PCL)-hydrogel construct for segmental bone repair showing good bonding at the scaffold hydrogel interface and even cell distribution. The results show that MSCs cultured in a collagen I hydrogel are able to undergo a distinct osteogenic differentiation pathway when stimulated with specific differentiation factors and suggest that collagen I hydrogels are a suitable means to facilitate cell seeding of scaffolds for bone tissue engineering applications.

  2. Fabrication of polycaprolactone collagen hydrogel constructs seeded with mesenchymal stem cells for bone regeneration

    International Nuclear Information System (INIS)

    The osteogenic differentiation of bone marrow-derived human mesenchymal stem cells (MSCs) in a collagen I hydrogel was investigated. Collagen hydrogels with 7.5 x 105 MSCs ml-1 were fabricated and cultured for 6 weeks in a defined, osteogenic differentiation medium. Histochemistry revealed morphologically distinct, chondrocyte-like cells, surrounded by a sulfated proteoglycan-rich extracellular matrix in the group treated with bone morphogenetic protein 2 (BMP-2), while cells cultured with dexamethasone, ascorbate-2-phosphate, and β-glycerophosphate displayed a spindle-shaped morphology and deposited a mineralized matrix. Real-time polymerase chain reaction (RT-PCR) analyses revealed a specific chondrogenic differentiation with the expression of cartilage-specific markers in the BMP-2-treated group and a distinct expression pattern of the osteogenic markers alkaline phosphatase (ALP), type I collagen, osteocalcin (OC), and cbfa-1 in the group treated with an osteogenic standard medium. The collagen gels were used to engineer a cell laden medical grade ε-polycaprolactone (PCL)-hydrogel construct for segmental bone repair showing good bonding at the scaffold hydrogel interface and even cell distribution. The results show that MSCs cultured in a collagen I hydrogel are able to undergo a distinct osteogenic differentiation pathway when stimulated with specific differentiation factors and suggest that collagen I hydrogels are a suitable means to facilitate cell seeding of scaffolds for bone tissue engineering applications.

  3. Adipose-Derived Stem Cell-Seeded Hydrogels Increase Endogenous Progenitor Cell Recruitment and Neovascularization in Wounds.

    Science.gov (United States)

    Kosaraju, Revanth; Rennert, Robert C; Maan, Zeshaan N; Duscher, Dominik; Barrera, Janos; Whittam, Alexander J; Januszyk, Michael; Rajadas, Jayakumar; Rodrigues, Melanie; Gurtner, Geoffrey C

    2016-02-01

    Adipose-derived mesenchymal stem cells (ASCs) are appealing for cell-based wound therapies because of their accessibility and ease of harvest, but their utility is limited by poor cell survival within the harsh wound microenvironment. In prior work, our laboratory has demonstrated that seeding ASCs within a soft pullulan-collagen hydrogel enhances ASC survival and improves wound healing. To more fully understand the mechanism of this therapy, we examined whether ASC-seeded hydrogels were able to modulate the recruitment and/or functionality of endogenous progenitor cells. Employing a parabiosis model and fluorescence-activated cell sorting analysis, we demonstrate that application of ASC-seeded hydrogels to wounds, when compared with injected ASCs or a noncell control, increased the recruitment of provascular circulating bone marrow-derived mesenchymal progenitor cells (BM-MPCs). BM-MPCs comprised 23.0% of recruited circulating progenitor cells in wounds treated with ASC-seeded hydrogels versus 8.4% and 2.1% in those treated with controls, p functional modulation of BM-MPCs, we demonstrate a statistically significant increase in BM-MPC migration, proliferation, and tubulization when exposed to hydrogel-seeded ASC-conditioned medium versus control ASC-conditioned medium (73.8% vs. 51.4% scratch assay closure; 9.1% vs. 1.4% proliferation rate; 10.2 vs. 5.5 tubules/HPF; p assays). BM-MPC expression of genes related to cell stemness and angiogenesis was also significantly increased following exposure to hydrogel-seeded ASC-conditioned medium (p functionality to effect greater neovascularization. PMID:26871860

  4. Intramyocardial delivery of mesenchymal stem cell-seeded hydrogel preserves cardiac function and attenuates ventricular remodeling after myocardial infarction.

    Directory of Open Access Journals (Sweden)

    Eva Mathieu

    Full Text Available BACKGROUND: To improve the efficacy of bone marrow-derived mesenchymal stem cell (MSC therapy targeted to infarcted myocardium, we investigated whether a self-setting silanized hydroxypropyl methylcellulose (Si-HPMC hydrogel seeded with MSC (MSC+hydrogel could preserve cardiac function and attenuate left ventricular (LV remodeling during an 8-week follow-up study in a rat model of myocardial infarction (MI. METHODOLOGY/PRINCIPAL FINDING: Si-HPMC hydrogel alone, MSC alone or MSC+hydrogel were injected into the myocardium immediately after coronary artery ligation in female Lewis rats. Animals in the MSC+hydrogel group showed an increase in cardiac function up to 28 days after MI and a mid-term prevention of cardiac function alteration at day 56. Histological analyses indicated that the injection of MSC+hydrogel induced a decrease in MI size and an increase in scar thickness and ultimately limited the transmural extent of MI. These findings show that intramyocardial injection of MSC+hydrogel induced short-term recovery of ventricular function and mid-term attenuation of remodeling after MI. CONCLUSION/SIGNIFICANCE: These beneficial effects may be related to the specific scaffolding properties of the Si-HPMC hydrogel that may provide the ability to support MSC injection and engraftment within myocardium.

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

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    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.

  6. 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

  7. Photocrosslinked nanocomposite hydrogels from PEG and silica nanospheres: structural, mechanical and cell adhesion characteristics.

    Science.gov (United States)

    Gaharwar, Akhilesh K; Rivera, Christian; Wu, Chia-Jung; Chan, Burke K; Schmidt, Gudrun

    2013-04-01

    Photopolymerized hydrogels are extensively investigated for various tissue engineering applications, primarily due to their ability to form hydrogels in a minimally invasive manner. Although photocrosslinkable hydrogels provide necessary biological and chemical characteristics to mimic cellular microenvironments, they often lack sufficient mechanical properties. Recently, nanocomposite approaches have demonstrated potential to overcome these deficits by reinforcing the hydrogel network with. In this study, we investigate some physical, chemical, and biological properties of photocrosslinked poly(ethylene glycol) (PEG)-silica hydrogels. The addition of silica nanospheres significantly suppresses the hydration degree of the PEG hydrogels, indicating surface interactions between the silica nanospheres and the polymer chains. No significant change in hydrogel microstructure or average pore size due to the addition of silica nanospheres was observed. However, addition of silica nanospheres significantly increases both the mechanical strength and the toughness of the hydrogel networks. The biological properties of these nanocomposite hydrogels were evaluated by seeding fibroblast cells on the hydrogel surface. While the PEG hydrogels showed minimum cell adhesion, spreading and proliferation, the addition of silica nanospheres enhanced initial cell adhesion, promoted cell spreading and increased the metabolic activity of the cells. Overall, results indicate that the addition of silica nanospheres improves the mechanical stiffness and cell adhesion properties of PEG hydrogels and can be used for biomedical applications that required controlled cell adhesion. PMID:23827639

  8. Photocrosslinked nanocomposite hydrogels from PEG and silica nanospheres: Structural, mechanical and cell adhesion characteristics

    International Nuclear Information System (INIS)

    Photopolymerized hydrogels are extensively investigated for various tissue engineering applications, primarily due to their ability to form hydrogels in a minimally invasive manner. Although photocrosslinkable hydrogels provide necessary biological and chemical characteristics to mimic cellular microenvironments, they often lack sufficient mechanical properties. Recently, nanocomposite approaches have demonstrated potential to overcome these deficits by reinforcing the hydrogel network with. In this study, we investigate some physical, chemical, and biological properties of photocrosslinked poly(ethylene glycol) (PEG)-silica hydrogels. The addition of silica nanospheres significantly suppresses the hydration degree of the PEG hydrogels, indicating surface interactions between the silica nanospheres and the polymer chains. No significant change in hydrogel microstructure or average pore size due to the addition of silica nanospheres was observed. However, addition of silica nanospheres significantly increases both the mechanical strength and the toughness of the hydrogel networks. The biological properties of these nanocomposite hydrogels were evaluated by seeding fibroblast cells on the hydrogel surface. While the PEG hydrogels showed minimum cell adhesion, spreading and proliferation, the addition of silica nanospheres enhanced initial cell adhesion, promoted cell spreading and increased the metabolic activity of the cells. Overall, results indicate that the addition of silica nanospheres improves the mechanical stiffness and cell adhesion properties of PEG hydrogels and can be used for biomedical applications that required controlled cell adhesion. - Graphical abstract: Structural, mechanical and biological properties of photocrosslinked nanocomposite hydrogels from silica and poly(ethylene oxide) are investigated. Silica reinforce the hydrogel network and improved mechanical strength. Addition of induces cell adhesion characteristic properties for various

  9. Photocrosslinked nanocomposite hydrogels from PEG and silica nanospheres: Structural, mechanical and cell adhesion characteristics

    Energy Technology Data Exchange (ETDEWEB)

    Gaharwar, Akhilesh K., E-mail: agaharwa@purdue.edu; Rivera, Christian; Wu, Chia-Jung; Chan, Burke K.; Schmidt, Gudrun

    2013-04-01

    Photopolymerized hydrogels are extensively investigated for various tissue engineering applications, primarily due to their ability to form hydrogels in a minimally invasive manner. Although photocrosslinkable hydrogels provide necessary biological and chemical characteristics to mimic cellular microenvironments, they often lack sufficient mechanical properties. Recently, nanocomposite approaches have demonstrated potential to overcome these deficits by reinforcing the hydrogel network with. In this study, we investigate some physical, chemical, and biological properties of photocrosslinked poly(ethylene glycol) (PEG)-silica hydrogels. The addition of silica nanospheres significantly suppresses the hydration degree of the PEG hydrogels, indicating surface interactions between the silica nanospheres and the polymer chains. No significant change in hydrogel microstructure or average pore size due to the addition of silica nanospheres was observed. However, addition of silica nanospheres significantly increases both the mechanical strength and the toughness of the hydrogel networks. The biological properties of these nanocomposite hydrogels were evaluated by seeding fibroblast cells on the hydrogel surface. While the PEG hydrogels showed minimum cell adhesion, spreading and proliferation, the addition of silica nanospheres enhanced initial cell adhesion, promoted cell spreading and increased the metabolic activity of the cells. Overall, results indicate that the addition of silica nanospheres improves the mechanical stiffness and cell adhesion properties of PEG hydrogels and can be used for biomedical applications that required controlled cell adhesion. - Graphical abstract: Structural, mechanical and biological properties of photocrosslinked nanocomposite hydrogels from silica and poly(ethylene oxide) are investigated. Silica reinforce the hydrogel network and improved mechanical strength. Addition of induces cell adhesion characteristic properties for various

  10. HPMA-RGD Hydrogels Seeded with Mesenchymal Stem Cells Improve Functional Outcome in Chronic Spinal Cord Injury

    Czech Academy of Sciences Publication Activity Database

    Hejčl, Aleš; Šedý, Jiří; Kapcalová, Miroslava; Arboleda Toro, David; Amemori, Takashi; Lesný, Petr; Likavčanová, Katarína; Krumbholcová, Eva; Přádný, Martin; Michálek, Jiří; Burian, M.; Hájek, M.; Jendelová, Pavla; Syková, Eva

    2010-01-01

    Roč. 19, č. 10 (2010), s. 1535-1546. ISSN 1547-3287 R&D Projects: GA MŠk(CZ) LC554; GA AV ČR IAA500390902 Grant ostatní: GA ČR(CZ) GD309/08/H079; GA MZd(CZ) 1A8697; GA MŠk(CZ) 1M0538; EC FP6 project RESCUE(XE) LSHB-CT-2005-518233 Institutional research plan: CEZ:AV0Z50390703; CEZ:AV0Z40500505 Keywords : magnetic-resonance tracking * spinal cord injury * stem cells Subject RIV: FH - Neurology Impact factor: 4.791, year: 2010

  11. Evaluation of a mPEG-polyester-based hydrogel as cell carrier for chondrocytes.

    Science.gov (United States)

    Peng, Sydney; Yang, Shu-Rui; Ko, Chao-Yin; Peng, Yu-Shiang; Chu, I-Ming

    2013-11-01

    Temperature-sensitive hydrogels are attractive alternatives to porous cell-seeded scaffolds and is minimally invasive through simple injection and in situ gelling. In this study, we compared the performance of two types of temperature-sensitive hydrogels on chondrocytes encapsulation for the use of tissue engineering of cartilage. The two hydrogels are composed of methoxy poly(ethylene glycol)- poly(lactic-co-valerolactone) (mPEG-PVLA), and methoxy poly(ethylene glycol)-poly(lactic- co-glycolide) (mPEG-PLGA). Osmolarity and pH were optimized through the manipulation of polymer concentration and dispersion medium. Chondrocytes proliferation in mPEG-PVLA hydrogels was observed as well as accumulation of GAGs and collagen. On the other hand, chondrocytes encapsulated in mPEG-PLGA hydrogels showed low viability and chondrogenesis. Also, mPEG-PVLA hydrogel, which is more hydrophobic, retained physical integrity after 14 days while mPEG-PLGA hydrogel underwent full degradation due to faster hydrolysis rate and more pronounced acidic self-catalyzed degradation. The mPEG-PVLA hydrogel can be furthered tuned by manipulation of molecular weights to obtain hydrogels with different swelling and degradation characteristics, which may be useful as producing a selection of hydrogels compatible with different cell types. Taken together, these results demonstrate that mPEG-PVLA hydrogels are promising to serve as three-dimensional cell carriers for chondrocytes and potentially applicable in cartilage tissue engineering. PMID:24039062

  12. 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.

  13. 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

  14. Evaluation of Gelatin Microparticles as Adherent-Substrates for Mesenchymal Stem Cells in a Hydrogel Composite.

    Science.gov (United States)

    Lu, Steven; Lee, Esther J; Lam, Johnny; Tabata, Yasuhiko; Mikos, Antonios G

    2016-06-01

    Due to the lack of cell-adhesive moieties in traditional synthetic hydrogels, the present work investigated the use of degradable gelatin microparticles (GMPs) as temporary adherent substrates for anchorage-dependent mesenchymal stem cells (MSCs). MSCs were seeded onto GMPs of varying crosslinking densities and sizes to investigate their role on influencing MSC differentiation and aggregation. The MSC-seeded GMPs were then encapsulated in poly(ethylene glycol)-based hydrogels and cultured in serum-free, growth factor-free osteochondral medium. Non-seeded MSCs co-encapsulated with GMPs in the hydrogels were used as a control for comparison. Over the course of 35 days, MSCs seeded on GMPs exhibited more cell-cell contacts, greater chondrogenic potential, and a down-regulation of osteogenic markers compared to the controls. Although the factors of GMP crosslinking and size had nominal influence on MSC differentiation and aggregation, GMPs demonstrate potential as an adherent-substrate for improving cell delivery from hydrogel scaffolds by facilitating cell-cell contacts and improving MSC differentiation. PMID:26935924

  15. The enhancement of chondrogenesis of ATDC5 cells in RGD-immobilized microcavitary alginate hydrogels.

    Science.gov (United States)

    Yao, Yongchang; Zeng, Lei; Huang, Yuyang

    2016-07-01

    In our previous work, we have developed an effective microcavitary alginate hydrogel for proliferation of chondrocytes and maintenance of chondrocytic phenotype. In present work, we investigated whether microcavitary alginate hydrogel could promote the chondrogenesis of progenitor cells. Moreover, we attempted to further optimize this system by incorporating synthetic Arg-Gly-Asp peptide. ATDC5 cells were seeded into microcavitary alginate hydrogel with or without Arg-Gly-Asp immobilization. Cell Counting Kit-8 and live/dead staining were conducted to analyze cell proliferation. Real-time polymerase chain reaction (RT-PCR), hematoxylin and eosin, and Toluidine blue O staining as well as Western blot assay was performed to evaluate the cartilaginous markers at transcriptional level and at protein level, respectively. The obtained data demonstrated that Arg-Gly-Asp-immobilized microcavitary alginate hydrogel was preferable to promote the cell proliferation. Also, Arg-Gly-Asp-immobilized microcavitary alginate hydrogel improved the expression of chondrocytic genes including Collagen II and Aggrecan when compared with microcavitary alginate hydrogel. The results suggested that microcavitary alginate hydrogel could promote the chondrogenesis. And Arg-Gly-Asp would be promising to ameliorate this culture system for cartilage tissue engineering. PMID:27000189

  16. Biochemical and structural characterization of neocartilage formed by mesenchymal stem cells in alginate hydrogels.

    Directory of Open Access Journals (Sweden)

    Magnus Ø Olderøy

    Full Text Available A popular approach to make neocartilage in vitro is to immobilize cells with chondrogenic potential in hydrogels. However, functional cartilage cannot be obtained by control of cells only, as function of cartilage is largely dictated by architecture of extracellular matrix (ECM. Therefore, characterization of the cells, coupled with structural and biochemical characterization of ECM, is essential in understanding neocartilage assembly to create functional implants in vitro. We focused on mesenchymal stem cells (MSC immobilized in alginate hydrogels, and used immunohistochemistry (IHC and gene expression analysis combined with advanced microscopy techniques to describe properties of cells and distribution and organization of the forming ECM. In particular, we used second harmonic generation (SHG microscopy and focused ion beam/scanning electron microscopy (FIB/SEM to study distribution and assembly of collagen. Samples with low cell seeding density (1e7 MSC/ml showed type II collagen molecules distributed evenly through the hydrogel. However, SHG microscopy clearly indicated only pericellular localization of assembled fibrils. Their distribution was improved in hydrogels seeded with 5e7 MSC/ml. In those samples, FIB/SEM with nm resolution was used to visualize distribution of collagen fibrils in a three dimensional network extending from the pericellular region into the ECM. In addition, distribution of enzymes involved in procollagen processing were investigated in the alginate hydrogel by IHC. It was discovered that, at high cell seeding density, procollagen processing and fibril assembly was also occurring far away from the cell surface, indicating sufficient transport of procollagen and enzymes in the intercellular space. At lower cell seeding density, the concentration of enzymes involved in procollagen processing was presumably too low. FIB/SEM and SHG microscopy combined with IHC localization of specific proteins were shown to provide

  17. Controlled Cell Growth and Cell Migration in Periodic Mesoporous Organosilica/Alginate Nanocomposite Hydrogels.

    Science.gov (United States)

    Seda Kehr, Nermin; Riehemann, Kristina

    2016-01-21

    Nanocomposite (NC) hydrogels with different periodic mesoporous organosilica (PMO) concentrations and a NC hydrogel bilayer with various PMO concentrations inside the layers of the hydrogel matrix are prepared. The effect of the PMO concentration on cell growth and migration of cells is reported. The cells migrate in the bilayer NC hydrogel towards higher PMO concentrations and from cell culture plates to NC hydrogel scaffolds. PMID:26648333

  18. A fibrin/hyaluronic acid hydrogel for the delivery of mesenchymal stem cells and potential for articular cartilage repair

    OpenAIRE

    Snyder, Timothy N; Madhavan, Krishna; Intrator, Miranda; Dregalla, Ryan C.; Park, Daewon

    2014-01-01

    Background Osteoarthritis (OA) is a degenerative joint disease affecting approximately 27 million Americans, and even more worldwide. OA is characterized by degeneration of subchondral bone and articular cartilage. In this study, a chondrogenic fibrin/hyaluronic acid (HA)-based hydrogel seeded with bone marrow-derived mesenchymal stem cells (BMSCs) was investigated as a method of regenerating these tissues for OA therapy. This chondrogenic hydrogel system can be delivered in a minimally invas...

  19. 3D Cell Culture in Alginate Hydrogels

    Directory of Open Access Journals (Sweden)

    Therese Andersen

    2015-03-01

    Full Text Available This review compiles information regarding the use of alginate, and in particular alginate hydrogels, in culturing cells in 3D. Knowledge of alginate chemical structure and functionality are shown to be important parameters in design of alginate-based matrices for cell culture. Gel elasticity as well as hydrogel stability can be impacted by the type of alginate used, its concentration, the choice of gelation technique (ionic or covalent, and divalent cation chosen as the gel inducing ion. The use of peptide-coupled alginate can control cell–matrix interactions. Gelation of alginate with concomitant immobilization of cells can take various forms. Droplets or beads have been utilized since the 1980s for immobilizing cells. Newer matrices such as macroporous scaffolds are now entering the 3D cell culture product market. Finally, delayed gelling, injectable, alginate systems show utility in the translation of in vitro cell culture to in vivo tissue engineering applications. Alginate has a history and a future in 3D cell culture. Historically, cells were encapsulated in alginate droplets cross-linked with calcium for the development of artificial organs. Now, several commercial products based on alginate are being used as 3D cell culture systems that also demonstrate the possibility of replacing or regenerating tissue.

  20. Micropatterning cell adhesion on polyacrylamide hydrogels.

    Science.gov (United States)

    Zhang, Jian; Guo, Wei-Hui; Rape, Andrew; Wang, Yu-Li

    2013-01-01

    Cell shape and substrate rigidity play critical roles in regulating cell behaviors and fate. Controlling cell shape on elastic adhesive materials holds great promise for creating a physiologically relevant culture environment for basic and translational research and clinical applications. However, it has been technically challenging to create high-quality adhesive patterns on compliant substrates. We have developed an efficient and economical method to create precise micron-scaled adhesive patterns on the surface of a hydrogel (Rape et al., Biomaterials 32:2043-2051, 2011). This method will facilitate the research on traction force generation, cellular mechanotransduction, and tissue engineering, where precise controls of both materials rigidity and adhesive patterns are important. PMID:23955741

  1. Injectable shear-thinning nanoengineered hydrogels for stem cell delivery.

    Science.gov (United States)

    Thakur, Ashish; Jaiswal, Manish K; Peak, Charles W; Carrow, James K; Gentry, James; Dolatshahi-Pirouz, Alireza; Gaharwar, Akhilesh K

    2016-06-16

    Injectable hydrogels are investigated for cell encapsulation and delivery as they can shield cells from high shear forces. One of the approaches to obtain injectable hydrogels is to reinforce polymeric networks with high aspect ratio nanoparticles such as two-dimensional (2D) nanomaterials. 2D nanomaterials are an emerging class of ultrathin materials with a high degree of anisotropy and they strongly interact with polymers resulting in the formation of shear-thinning hydrogels. Here, we present 2D nanosilicate reinforced kappa-carrageenan (κCA) hydrogels for cellular delivery. κCA is a natural polysaccharide that resembles native glycosaminoglycans and can form brittle hydrogels via ionic crosslinking. The chemical modification of κCA with photocrosslinkable methacrylate groups renders the formation of a covalently crosslinked network (MκCA). Reinforcing the MκCA with 2D nanosilicates results in shear-thinning characteristics, and enhanced mechanical stiffness, elastomeric properties, and physiological stability. The shear-thinning characteristics of nanocomposite hydrogels are investigated for human mesenchymal stem cell (hMSC) delivery. The hMSCs showed high cell viability after injection and encapsulated cells showed a circular morphology. The proposed shear-thinning nanoengineered hydrogels can be used for cell delivery for cartilage tissue regeneration and 3D bioprinting. PMID:27270567

  2. Injectable shear-thinning nanoengineered hydrogels for stem cell delivery

    Science.gov (United States)

    Thakur, Ashish; Jaiswal, Manish K.; Peak, Charles W.; Carrow, James K.; Gentry, James; Dolatshahi-Pirouz, Alireza; Gaharwar, Akhilesh K.

    2016-06-01

    Injectable hydrogels are investigated for cell encapsulation and delivery as they can shield cells from high shear forces. One of the approaches to obtain injectable hydrogels is to reinforce polymeric networks with high aspect ratio nanoparticles such as two-dimensional (2D) nanomaterials. 2D nanomaterials are an emerging class of ultrathin materials with a high degree of anisotropy and they strongly interact with polymers resulting in the formation of shear-thinning hydrogels. Here, we present 2D nanosilicate reinforced kappa-carrageenan (κCA) hydrogels for cellular delivery. κCA is a natural polysaccharide that resembles native glycosaminoglycans and can form brittle hydrogels via ionic crosslinking. The chemical modification of κCA with photocrosslinkable methacrylate groups renders the formation of a covalently crosslinked network (MκCA). Reinforcing the MκCA with 2D nanosilicates results in shear-thinning characteristics, and enhanced mechanical stiffness, elastomeric properties, and physiological stability. The shear-thinning characteristics of nanocomposite hydrogels are investigated for human mesenchymal stem cell (hMSC) delivery. The hMSCs showed high cell viability after injection and encapsulated cells showed a circular morphology. The proposed shear-thinning nanoengineered hydrogels can be used for cell delivery for cartilage tissue regeneration and 3D bioprinting.

  3. A practical guide to hydrogels for cell culture.

    Science.gov (United States)

    Caliari, Steven R; Burdick, Jason A

    2016-04-28

    There is growing appreciation of the role that the extracellular environment plays in regulating cell behavior. Mechanical, structural, and compositional cues, either alone or in concert, can drastically alter cell function. Biomaterials, and particularly hydrogels, have been developed and implemented to present defined subsets of these cues for investigating countless cellular processes as a means of understanding morphogenesis, aging, and disease. Although most scientists concede that standard cell culture materials (tissue culture plastic and glass) do a poor job of recapitulating native cellular milieus, there is currently a knowledge barrier for many researchers in regard to the application of hydrogels for cell culture. Here, we introduce hydrogels to those who may be unfamiliar with procedures to culture and study cells with these systems, with a particular focus on commercially available hydrogels. PMID:27123816

  4. In vivo bioluminescence imaging for viable human neural stem cells incorporated within in situ gelatin hydrogels

    OpenAIRE

    Hwang, Do Won; Park, Kyung Min; Shim, Hye-kyung; Jin, Yeona; Oh, Hyun Jeong; Oh, So Won; Lee, Song; Youn, Hyewon; Joung, Yoon Ki; Lee, Hong J.; Kim, Seung U.; Park, Ki Dong; Lee, Dong Soo

    2014-01-01

    Background Three-dimensional (3D) hydrogel-based stem cell therapies contribute to enhanced therapeutic efficacy in treating diseases, and determining the optimal mechanical strength of the hydrogel in vivo is important for therapeutic success. We evaluated the proliferation of human neural stem cells incorporated within in situ-forming hydrogels and compared the effect of hydrogels with different elastic properties in cell/hydrogel-xenografted mice. Methods The gelatin-polyethylene glycol-ty...

  5. Designing Cell-Compatible Hydrogels for Biomedical Applications

    Science.gov (United States)

    Seliktar, Dror

    2012-06-01

    Hydrogels are polymeric materials distinguished by high water content and diverse physical properties. They can be engineered to resemble the extracellular environment of the body’s tissues in ways that enable their use in medical implants, biosensors, and drug-delivery devices. Cell-compatible hydrogels are designed by using a strategy of coordinated control over physical properties and bioactivity to influence specific interactions with cellular systems, including spatial and temporal patterns of biochemical and biomechanical cues known to modulate cell behavior. Important new discoveries in stem cell research, cancer biology, and cellular morphogenesis have been realized with model hydrogel systems premised on these designs. Basic and clinical applications for hydrogels in cell therapy, tissue engineering, and biomedical research continue to drive design improvements using performance-based materials engineering paradigms.

  6. 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

  7. SYNTHETIC HYDROGELS AS SCAFFOLDS FOR MANIPULATING ENDOTHELIUM CELL BEHAVIORS

    Institute of Scientific and Technical Information of China (English)

    Yong-mei Chen; Jing-jing Yang; Yoshihito Osada; Jian Ping Gong

    2011-01-01

    Synthetic hydrogels can be used as scaffolds that not only favor endothelial cells (ECs) proliferation but also manipulate the behaviors and functions of the ECs. In this review paper, the effect of chemical structure, Young’s modulus (E) and zeta potential (ζ) of synthetic hydrogel scaffolds on static cell behaviors, including cell morphology, proliferation,cytoskeleton structure and focal adhesion, and on dynamic cell behaviors, including migration velocity and morphology oscillation, as well as on EC function such as anti-platelet adhesion, are reported. It was found that negatively charged hydrogels, poly(2-acrylamido-2-methylpropanesulfonie sodium) (PNaAMPS) and poly(sodium p-styrene sulphonate) (PNaSS), can directly promote cell proliferation, with no need of surface modification by any cell-adhesive proteins or peptides at the environment of serum-containing medium. In addition, the Young’s modulus (E) and zeta potential (ζ) of hydrogel scaffolds are quantitatively tuned by copolymer hydrogels, poly(NaAMPS-co-DMAAm) and poly(NaSS-co-DMAAm), in which the two kinds of negatively charged monomers NaAMPS and NaSS are copolymerized with neutral monomer, N,N-dimethylacrylamide (DMAAm). It was found that the critical zeta potential of hydrogels manipulating EC morphology, proliferation, and motility is ζcritical = -20.83 mV and ζcritical = -14.0 mV for poly(NaAMPS-co-DMAAm) and poly(NaSS-co-DMAAm), respectively. The above mentioned EC behaviors well correlate with the adsorption of fibronectin,a kind of cell-adhesive protein, on the hydrogel surfaces. Furthermore, adhered platelets on the EC monolayers cultured on the hydrogel scaffolds obviously decreases with an increase of the Young’s modulus (E) of the hydrogels, especially when E > 60 kPa. Glycocalyx assay and gene expression of ECs demonstrate that the anti-platelet adhesion well correlates with the EC-specific glycocalyx. The above investigation suggests that understanding the relationship

  8. Biocompatible Hydrogels for Microarray Cell Printing and Encapsulation

    Directory of Open Access Journals (Sweden)

    Akshata Datar

    2015-10-01

    Full Text Available Conventional drug screening processes are a time-consuming and expensive endeavor, but highly rewarding when they are successful. To identify promising lead compounds, millions of compounds are traditionally screened against therapeutic targets on human cells grown on the surface of 96-wells. These two-dimensional (2D cell monolayers are physiologically irrelevant, thus, often providing false-positive or false-negative results, when compared to cells grown in three-dimensional (3D structures such as hydrogel droplets. However, 3D cell culture systems are not easily amenable to high-throughput screening (HTS, thus inherently low throughput, and requiring relatively large volume for cell-based assays. In addition, it is difficult to control cellular microenvironments and hard to obtain reliable cell images due to focus position and transparency issues. To overcome these problems, miniaturized 3D cell cultures in hydrogels were developed via cell printing techniques where cell spots in hydrogels can be arrayed on the surface of glass slides or plastic chips by microarray spotters and cultured in growth media to form cells encapsulated 3D droplets for various cell-based assays. These approaches can dramatically reduce assay volume, provide accurate control over cellular microenvironments, and allow us to obtain clear 3D cell images for high-content imaging (HCI. In this review, several hydrogels that are compatible to microarray printing robots are discussed for miniaturized 3D cell cultures.

  9. Biocompatible Hydrogels for Microarray Cell Printing and Encapsulation

    Science.gov (United States)

    Datar, Akshata; Joshi, Pranav; Lee, Moo-Yeal

    2015-01-01

    Conventional drug screening processes are a time-consuming and expensive endeavor, but highly rewarding when they are successful. To identify promising lead compounds, millions of compounds are traditionally screened against therapeutic targets on human cells grown on the surface of 96-wells. These two-dimensional (2D) cell monolayers are physiologically irrelevant, thus, often providing false-positive or false-negative results, when compared to cells grown in three-dimensional (3D) structures such as hydrogel droplets. However, 3D cell culture systems are not easily amenable to high-throughput screening (HTS), thus inherently low throughput, and requiring relatively large volume for cell-based assays. In addition, it is difficult to control cellular microenvironments and hard to obtain reliable cell images due to focus position and transparency issues. To overcome these problems, miniaturized 3D cell cultures in hydrogels were developed via cell printing techniques where cell spots in hydrogels can be arrayed on the surface of glass slides or plastic chips by microarray spotters and cultured in growth media to form cells encapsulated 3D droplets for various cell-based assays. These approaches can dramatically reduce assay volume, provide accurate control over cellular microenvironments, and allow us to obtain clear 3D cell images for high-content imaging (HCI). In this review, several hydrogels that are compatible to microarray printing robots are discussed for miniaturized 3D cell cultures. PMID:26516921

  10. Investigation of hydrogel isolated from seeds of Ocimum basilicum as binder

    Directory of Open Access Journals (Sweden)

    Bhosale A

    2009-01-01

    Full Text Available Ayurvedic powders are widely used as therapeutic agents but most of them have unpleasant taste and large doses. One of the possible approach to overcome these drawbacks is to represent them in unit dosage form i.e. tablet dosage form. The purpose of this study is to elucidate and quantify the compressibility and compactibility of herbal granules prepared by using hydrogel isolated from whole seeds of Ocimum basilicum as a novel binder. The compressibility is the ability of the powder to deform under pressure and the compactibility is the ability of a powder to form coherent compacts. To test the functionality of novel excipients, Sonnergaard proved a simple linear model to confirm compactability, which is an uncomplicated tool for quantification. The tablets were compressed at increasing compression pressures and were evaluated for various mechanical properties. The linear relationship between specific crushing strength and compression pressure revealed the compactibility of the herbal granules and the linear relationship between porosity and logarithm of compression pressure revealed the compressible nature of the herbal granules according to the model developed by Sonnergaard. Thus the hydrogel isolated from whole seeds of Ocimum basillicum had potential as a granulating and binding agent.

  11. Hydrogel formulation determines cell fate of fetal and adult neural progenitor cells

    Directory of Open Access Journals (Sweden)

    Emily R. Aurand

    2014-01-01

    Full Text Available Hydrogels provide a unique tool for neural tissue engineering. These materials can be customized for certain functions, i.e. to provide cell/drug delivery or act as a physical scaffold. Unfortunately, hydrogel complexities can negatively impact their biocompatibility, resulting in unintended consequences. These adverse effects may be combated with a better understanding of hydrogel chemical, physical, and mechanical properties, and how these properties affect encapsulated neural cells. We defined the polymerization and degradation rates and compressive moduli of 25 hydrogels formulated from different concentrations of hyaluronic acid (HA and poly(ethylene glycol (PEG. Changes in compressive modulus were driven primarily by the HA concentration. The in vitro biocompatibility of fetal-derived (fNPC and adult-derived (aNPC neural progenitor cells was dependent on hydrogel formulation. Acute survival of fNPC benefited from hydrogel encapsulation. NPC differentiation was divergent: fNPC differentiated into mostly glial cells, compared with neuronal differentiation of aNPC. Differentiation was influenced in part by the hydrogel mechanical properties. This study indicates that there can be a wide range of HA and PEG hydrogels compatible with NPC. Additionally, this is the first study comparing hydrogel encapsulation of NPC derived from different aged sources, with data suggesting that fNPC and aNPC respond dissimilarly within the same hydrogel formulation.

  12. Hyaluronic Acid-Human Blood Hydrogels for Stem Cell Transplantation

    OpenAIRE

    Connie Y. Chang; Chan, Angel; Armstrong, Patrick; Luo, Hong-Chang; Higuchi, Takahiro; Strehin, Iossif; Vakrou, Styliani; Lin, Xiaoping; Brown, Sophia; O’Rourke, Brian; Abraham, Theodore P.; Wahl, Richard; Steenbergen, Charles; ELISSEEFF, JENNIFER; Abraham, M. Roselle

    2012-01-01

    Tissue engineering-based approaches have the potential to improve stem cell engraftment by increasing cell delivery to the myocardium. Our objective was to develop and characterize a naturally-derived, autologous, biodegradable hydrogel in order to improve acute stem cell retention in the myocardium. HA-blood hydrogels(HA-Bl) were synthesized by mixing in a 1:1(v/v) ratio, lysed whole blood and hyaluronic acid(HA), whose carboxyl groups were functionalized with N-hydroxysuccinimide(NHS) to yi...

  13. Tough and Cell-Compatible Chitosan Physical Hydrogels for Mouse Bone Mesenchymal Stem Cells in Vitro.

    Science.gov (United States)

    Ding, Beibei; Gao, Huichang; Song, Jianhui; Li, Yaya; Zhang, Lina; Cao, Xiaodong; Xu, Min; Cai, Jie

    2016-08-01

    Most hydrogels involve synthetic polymers and organic cross-linkers that cannot simultaneously fulfill the mechanical and cell-compatibility requirements of biomedical applications. We prepared a new type of chitosan physical hydrogel with various degrees of deacetylation (DDs) via the heterogeneous deacetylation of nanoporous chitin hydrogels under mild conditions. The DD of the chitosan physical hydrogels ranged from 56 to 99%, and the hydrogels were transparent and mechanically strong because of the extra intra- and intermolecular hydrogen bonding interactions between the amino and hydroxyl groups on the nearby chitosan nanofibrils. The tensile strength and Young's modulus of the chitosan physical hydrogels were 3.6 and 7.9 MPa, respectively, for a DD of 56% and increased to 12.1 and 92.0 MPa for a DD of 99% in a swelling equilibrium state. In vitro studies demonstrated that mouse bone mesenchymal stem cells (mBMSCs) cultured on chitosan physical hydrogels had better adhesion and proliferation than those cultured on chitin hydrogels. In particular, the chitosan physical hydrogels promoted the differentiation of the mBMSCs into epidermal cells in vitro. These materials are promising candidates for applications such as stem cell research, cell therapy, and tissue engineering. PMID:27410199

  14. Sundew-Inspired Adhesive Hydrogels Combined with Adipose-Derived Stem Cells for Wound Healing.

    Science.gov (United States)

    Sun, Leming; Huang, Yujian; Bian, Zehua; Petrosino, Jennifer; Fan, Zhen; Wang, Yongzhong; Park, Ki Ho; Yue, Tao; Schmidt, Michael; Galster, Scott; Ma, Jianjie; Zhu, Hua; Zhang, Mingjun

    2016-01-27

    The potential to harness the unique physical, chemical, and biological properties of the sundew (Drosera) plant's adhesive hydrogels has long intrigued researchers searching for novel wound-healing applications. However, the ability to collect sufficient quantities of the sundew plant's adhesive hydrogels is problematic and has eclipsed their therapeutic promise. Inspired by these natural hydrogels, we asked if sundew-inspired adhesive hydrogels could overcome the drawbacks associated with natural sundew hydrogels and be used in combination with stem-cell-based therapy to enhance wound-healing therapeutics. Using a bioinspired approach, we synthesized adhesive hydrogels comprised of sodium alginate, gum arabic, and calcium ions to mimic the properties of the natural sundew-derived adhesive hydrogels. We then characterized and showed that these sundew-inspired hydrogels promote wound healing through their superior adhesive strength, nanostructure, and resistance to shearing when compared to other hydrogels in vitro. In vivo, sundew-inspired hydrogels promoted a "suturing" effect to wound sites, which was demonstrated by enhanced wound closure following topical application of the hydrogels. In combination with mouse adipose-derived stem cells (ADSCs) and compared to other therapeutic biomaterials, the sundew-inspired hydrogels demonstrated superior wound-healing capabilities. Collectively, our studies show that sundew-inspired hydrogels contain ideal properties that promote wound healing and suggest that sundew-inspired-ADSCs combination therapy is an efficacious approach for treating wounds without eliciting noticeable toxicity or inflammation. PMID:26731614

  15. 3D porous biomimetically modified hydrogels supporting stem cells adhesion

    Czech Academy of Sciences Publication Activity Database

    Studenovská, Hana; Vodička, Petr; Proks, Vladimír; Juhásová, Jana; Motlík, Jan; Rypáček, František

    Dublin : National University of Ireland , 2011. s. 119, psiii-630. [Annual Conference of the European Society for Biomaterials /24./. 04.09.2011-08.09.2011, Dublin] R&D Projects: GA MŠk 1M0538 Institutional research plan: CEZ:AV0Z40500505; CEZ:AV0Z50450515 Keywords : porous hydrogel * cell adhesion * polypeptide Subject RIV: FH - Neurology

  16. Osteogenic differentiation of human adipose-derived mesenchymal stem cells on gum tragacanth hydrogel.

    Science.gov (United States)

    Haeri, Seyed Mohammad Jafar; Sadeghi, Yousef; Salehi, Mohammad; Farahani, Reza Masteri; Mohsen, Nourozian

    2016-05-01

    Currently, natural polymer based hydrogels has attracted great attention of orthopedic surgeons for application in bone tissue engineering. With this aim, osteoinductive capacity of Gum Tragacanth (GT) based hydrogel was compared to collagen hydrogel and tissue culture plate (TCPS). For this purpose, adipose-derived mesenchymal stem cells (AT-MSCs) was cultured on the hydrogels and TCPS and after investigating the biocompatibility of hydrogels using MTT assay, osteoinductivity of hydrogels were evaluated using pan osteogenic markers such as Alizarin red staining, alkaline phosphatase (ALP) activity, calcium content and osteo-related genes. Increasing proliferation trend of AT-MSCs on GT hydrogel demonstrated that TG has no-cytotoxicity and can even be better than the other groups i.e., highest proliferation at day 5. GT hydrogel displayed highest ALP activity and mineralization when compared to the collagen hydrogel and TCPS. Relative gene expression levels have demonstrated that highest expression of Runx2, osteonectin and osteocalcin in the cells cultured GT hydrogel but the expression of collagen type-1 remains constant in hydrogels. Above results demonstrate that GT hydrogel could be an appropriate scaffold for accelerating and supporting the adhesion, proliferation and osteogenic differentiation of stem cells which further can be used for orthopedic applications. PMID:27055599

  17. Evaporation-based microfluidic production of oil-free cell-containing hydrogel particles

    OpenAIRE

    Fan, Rong; Naqvi, Kubra; Patel, Krishna; Sun, Jun; Wan, Jiandi

    2015-01-01

    We demonstrate an evaporation-based microfluidic strategy to produce oil-free cell containing hydrogel particles. Perfluoro-n-pentane, which is used as the continuous oil phase to generate cell-containing hydrogel (Extracel) particles, is removed at an elevated temperature. Human colon cancer cells (HCT116) encapsulated in the hydrogel particles show higher viability than cells encapsulated in particles that are produced via a non-evaporative oil phase. In addition, single HCT116 cells can be...

  18. Expression of COLLAGEN 1 and ELASTIN Genes in Mitral Valvular Interstitial Cells within Microfiber Reinforced Hydrogel

    Directory of Open Access Journals (Sweden)

    Eslami Maryam

    2015-10-01

    Full Text Available Objective The incidence of heart valve disease is increasing worldwide and the number of heart valve replacements is expected to increase in the future. By mimicking the main tissue structures and properties of heart valve, tissue engineering offers new options for the replacements. Applying an appropriate scaffold in fabricating tissue-engineered heart valves (TEHVs is of importance since it affects the secretion of the main extracellular matrix (ECM components, collagen 1 and elastin, which are crucial in providing the proper mechanical properties of TEHVs. Materials and Methods Using real-time polymerase chain reaction (PCR in this experi- mental study, the relative expression levels of COLLAGEN 1 and ELASTIN were obtained for three samples of each examined sheep mitral valvular interstitial cells (MVICs-seeded onto electrospun poly (glycerol sebacate (PGS-poly (ε-caprolactone (PCL microfibrous, gelatin and hyaluronic acid based hydrogel-only and composite (PGS-PCL/hydrogel scaffolds. This composite has been shown to create a synthetic three-dimensional (3D microenvironment with appropriate mechanical and biological properties for MVICs. Results Cell viability and metabolic activity were similar among all scaffold types. Our results showed that the level of relative expression of COLLAGEN 1 and ELASTIN genes was higher in the encapsulated composite scaffolds compared to PGS-PCL-only and hydrogel-only scaffolds with the difference being statistically significant (P<0.05. Conclusion The encapsulated composite scaffolds are more conducive to ECM secretion over the PGS-PCL-only and hydrogel-only scaffolds. This composite scaffold can serve as a model scaffold for heart valve tissue engineering.

  19. Odontogenic Differentiation of Human Dental Pulp Stem Cells on Hydrogel Scaffolds Derived from Decellularized Bone Extracellular Matrix and Collagen Type I.

    Directory of Open Access Journals (Sweden)

    Francesco Paduano

    Full Text Available The aim of this study was to evaluate the level of odontogenic differentiation of dental pulp stem cells (DPSCs on hydrogel scaffolds derived from bone extracellular matrix (bECM in comparison to those seeded on collagen I (Col-I, one of the main components of dental pulp ECM.DPSCs isolated from human third molars were characterized for surface marker expression and odontogenic potential prior to seeding into bECM or Col-I hydrogel scaffolds. The cells were then seeded onto bECM and Col-I hydrogel scaffolds and cultured under basal conditions or with odontogenic and growth factor (GF supplements. DPSCs cultivated on tissue culture polystyrene (TCPS with and without supplements were used as controls. Gene expression of dentin sialophosphoprotein (DSPP, dentin matrix protein 1 (DMP-1 and matrix extracellular phosphoglycoprotein (MEPE was evaluated by quantitative reverse transcription-polymerase chain reaction (qRT-PCR and mineral deposition was observed by Von Kossa staining.When DPSCs were cultured on bECM hydrogels, the mRNA expression levels of DSPP, DMP-1 and MEPE genes were significantly upregulated with respect to those cultured on Col-I scaffolds or TCPS in the absence of extra odontogenic inducers. In addition, more mineral deposition was observed on bECM hydrogel scaffolds as demonstrated by Von Kossa staining. Moreover, DSPP, DMP-1 and MEPE mRNA expressions of DPSCs cultured on bECM hydrogels were further upregulated by the addition of GFs or osteo/odontogenic medium compared to Col-I treated cells in the same culture conditions.These results demonstrate the potential of the bECM hydrogel scaffolds to stimulate odontogenic differentiation of DPSCs.

  20. Three-Dimensional Cell Culture of Vascular Networks on Biomimetic Hydrogel Scaffolds

    OpenAIRE

    Hulkkonen, Hanna

    2015-01-01

    In vitro modeling of vascular development (angiogenesis) remains challenging since cell behavior may be abnormal in traditional, simplified monocultures. To mimic the extracellular matrix, 3D-printed and uniform fibrin and fibrin/gelatin hydrogels were fabricated to support capillary morphogenesis of human endothelial cells and adipose stromal cells. A microextrusion method was optimized for printing of patterned hydrogels. The effects of topography and hydrogel formulation on capillary l...

  1. Enantiomorphous Periodic Mesoporous Organosilica-Based Nanocomposite Hydrogel Scaffolds for Cell Adhesion and Cell Enrichment.

    Science.gov (United States)

    Kehr, Nermin Seda

    2016-03-14

    The chemical functionalization of nanomaterials with bioactive molecules has been used as an effective tool to mimic extracellular matrix (ECM) and to study the cell-material interaction in tissue engineering applications. In this respect, this study demonstrates the use of enantiomerically functionalized periodic mesoporous organosilicas (PMO) for the generation of new multifunctional 3D nanocomposite (NC) hydrogels to control the affinity of cells to the hydrogel surfaces and so to control the enrichment of cells and simultaneous drug delivery in 3D network. The functionalization of PMO with enantiomers of bioactive molecules, preparation of their nanocomposite hydrogels, and the stereoselective interaction of them with selected cell types are described. The results show that the affinity of cells to the respective NC hydrogel scaffolds is affected by the nature of the biomolecule and its enantiomers, which is more pronounced in serum containing media. The differentiation of enantiomorphous NC hydrogels by cells is used to enrich one cell type from a mixture of two cells. Finally, PMO are utilized as nanocontainers to release two different dye molecules as a proof of principle for multidrug delivery in 3D NC hydrogel scaffolds. PMID:26811946

  2. Injectable hydrogel as cell carriers: Mechanism of beta-hairpin peptide hydrogel shear thinning, immediate recovery and effects on encapsulated cell payload

    Science.gov (United States)

    Yan, Congqi

    To facilitate future biomedical treatment with localized delivery and higher therapy efficacy, much research effort has been devoted recently to the development of hydrogel biomaterials to transport a therapy to in vivo target sites via simple syringe or catheter injection. Most injectable hydrogel materials are free flowing precursor solutions ex vivo that become crosslinked into hydrogels once injected in vivo in response to exposure to environmental stimuli. However, properties of the final hydrogel formed in vivo are unpredictable due to possible leakage, dilution or change of injected gel precursor solution. As an alternate, more recent strategy for injectable hydrogel therapies, beta-hairpin peptide-based hydrogels are a class of injectable hydrogel solids with significant potential use in injectable therapies. These physical hydrogels can shear-thin and consequently flow as a low-viscosity material under a sufficient shear stress but immediately recover back into a solid upon removal of the stress, allowing them to be injected as preformed gel solids. The shear-thinning and immediate self-healing properties of self-assembled beta-hairpin peptide hydrogels enable a direct delivery of gel-encapsulated cells via benign injection to tissue defect sites with well-defined final gel properties in vivo. In this dissertation, mechanisms of gel shear-thinning and immediate recovery were elucidated by investigating gel behavior during and after flow via mechanical and structural characterizations. All studied beta-hairpin hydrogels shear-thin during flow (gel network fracture into large hydrogel domains) and instantly recover after cessation of flow (gel domains are percolated which immediately reforms the solid hydrogel). Importantly, hydrogel flow behavior was further studied in a capillary geometry that mimicked the actual situation of syringe injection. It was observed that all beta-hairpin peptide hydrogels investigated displayed a promising flow profile for

  3. 3-Dimensional cell-laden nano-hydroxyapatite/protein hydrogels for bone regeneration applications

    Energy Technology Data Exchange (ETDEWEB)

    Sadat-Shojai, Mehdi, E-mail: msadatshojai@gmail.com [Department of Chemistry, College of Sciences, Shiraz University, Shiraz 71454 (Iran, Islamic Republic of); Department of Biomaterials, Iran Polymer and Petrochemical Institute, Tehran (Iran, Islamic Republic of); Khorasani, Mohammad-Taghi [Department of Biomaterials, Iran Polymer and Petrochemical Institute, Tehran (Iran, Islamic Republic of); Jamshidi, Ahmad [Department of Novel Drug Delivery Systems, Iran Polymer and Petrochemical Institute, Tehran (Iran, Islamic Republic of)

    2015-04-01

    The ability to encapsulate cells in three-dimensional (3D) protein-based hydrogels is potentially of benefit for tissue engineering and regenerative medicine. However, as a result of their poor mechanical strength, protein-based hydrogels have traditionally been considered for soft tissue engineering only. Hence, in this study we tried to render these hydrogels suitable for hard tissue regeneration, simply by incorporation of bioactive nano-hydroxyapatite (HAp) into a photocrosslinkable gelatin hydrogel. Different cell types were also encapsulated in three dimensions in the resulting composites to prepare cell-laden constructs. According to the results, HAp significantly improves the stiffness of gelatin hydrogels, while it maintains their structural integrity and swelling ratio. It was also found that while the bare hydrogel (control) was completely inert in terms of bioactivity, a homogeneous 3D mineralization occurs throughout the nanocomposites after incubation in simulated body fluid. Moreover, encapsulated cells readily elongated, proliferated, and formed a 3D interconnected network with neighboring cells in the nanocomposite, showing the suitability of the nano-HAp/protein hydrogels for cellular growth in 3D. Therefore, the hydrogel nanocomposites developed in this study may be promising candidates for preparing cell-laden tissue-like structures with enhanced stiffness and increased osteoconductivity to induce bone formation in vivo. - Highlights: • We tried to render protein-based hydrogels suitable for hard tissue regeneration. • We developed a three-component system comprising hydrogel, nano-HAp, and cells. • Nano-HAp significantly improved the mechanical strength of hydrogel. • Encapsulated cells readily elongated and proliferated in 3D cell-laden nanocomposite. • 3D deposition of bone crystals occurred in the hydrogel nanocomposites.

  4. 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

  5. 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

  6. 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

  7. 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.

  8. Formation of model hepatocellular aggregates in a hydrogel scaffold using degradable genipin crosslinked gelatin microspheres as cell carriers

    International Nuclear Information System (INIS)

    Primary hepatocyte is probably the preferred cell for cell therapy in liver regeneration. However, its non-ideal proliferation capacity and rapid loss of phenotype during 2D culture compromises the quality and quantity of the transplanted hepatocytes, resulting in variable success rates of this treatment. Many studies have shown that the formation of 3D hepatocellular spheroids aids in the maintenance of liver-specific functions in hepatocytes. However, many of the methodologies employed require a sophisticated set-up or specialized equipment which makes it uneconomical to scale up for clinical applications. In this study, we have developed dual-functioning genipin crosslinked gelatin microspheres that serve as cell carriers as well as porogens for delivering the model cells and also for creating cavities. The cells were first seeded onto genipin crosslinked gelatin microspheres for attachment, followed by encapsulation in alginate hydrogel. Collagenase, MMP-9, was introduced either in the culture media or mixed with alginate precursor solution to allow microsphere degradation for creating cavities within the gel bulk. Accordingly, the cells proliferate within the cavities, forming hepatocellular aggregates while the alginate hydrogel serves as a confinement, restricting the size and the shape of the aggregates to the size of the cavities. In addition, the final hepatocellular aggregates could be harvested from the system by removing the alginate hydrogel via citrate treatment. Therefore, this versatile platform not only has the advantage of injectability and simplicity, the cellular aggregates generated are in a controlled size and shape and can be extracted from the system. (paper)

  9. Temperature-sensitivity and cell biocompatibility of freeze-dried nanocomposite hydrogels incorporated with biodegradable PHBV

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Qingsong, E-mail: zqs8011@163.com; Chen, Li, E-mail: chenlis@tjpu.edu.cn; Dong, Youyu; Lu, Si

    2013-04-01

    The structure, morphology, thermal behaviors and cytotoxicity of novel hydrogels, composed of poly(N-isopropylacrylamide)(PNIPAM) and biodegradable polyester poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) under nanoclay hectorite “Laponite XLG” severed as physical cross-linker, were characterized by X-ray diffraction, scanning electron microscopy, gravimetric method, differential scanning calorimetry, and cell culture experiments. It was found that, due to the introduction of hydrophobic PHBV, the homogeneity of interior pore in the pure PNIPAM nanocomposite hydrogel was disrupted, the transparency and swelling degree gradually decreased. Although the weight ratio between PHBV and NIPAM increased from 5 to 40 wt.%, the volume phase transition temperature (VPTTs) of hydrogel were not altered compared with the pure PNIPAM nanocomposite hydrogel. No matter what PHBV content, the PHBV/PNIPAM/Hectorite hydrogels always exhibit good stimuli-responsibility. In addition, human hepatoma cells(HepG2) adhesion and spreading on the surface of PHBV-based hydrogels was greatly improved than that of pure PNIPAM nanocomposite hydrogel at 37 °C due to the introduction of PHBV. Highlights: ► Thermo-responsive and cell biocompatible hydrogels incorporated PHBV was synthesized. ► The introduction of PHBV decreases the transparency of nanocomposite hydrogel. ► The introduction of PHBV has a little shift on VPTTs of nanocomposite hydrogel. ► The HepG2 cells could adhere and spread on the surface of PHBV-based hydrogels. ► Cell sheet could be detached simultaneously from the surface of hydrogels.

  10. IGF-1 C Domain-Modified Hydrogel Enhances Cell Therapy for AKI.

    Science.gov (United States)

    Feng, Guowei; Zhang, Jimin; Li, Yang; Nie, Yan; Zhu, Dashuai; Wang, Ran; Liu, Jianfeng; Gao, Jie; Liu, Na; He, Ningning; Du, Wei; Tao, Hongyan; Che, Yongzhe; Xu, Yong; Kong, Deling; Zhao, Qiang; Li, Zongjin

    2016-08-01

    Low cell retention and engraftment after transplantation limit the successful application of stem cell therapy for AKI. Engineered microenvironments consisting of a hydrogel matrix and growth factors have been increasingly successful in controlling stem cell fate by mimicking native stem cell niche components. Here, we synthesized a bioactive hydrogel by immobilizing the C domain peptide of IGF-1 (IGF-1C) on chitosan, and we hypothesized that this hydrogel could provide a favorable niche for adipose-derived mesenchymal stem cells (ADSCs) and thereby enhance cell survival in an AKI model. In vitro studies demonstrated that compared with no hydrogel or chitosan hydrogel only, the chitosan-IGF-1C hydrogel increased cell viability through paracrine effects. In vivo, cotransplantation of the chitosan-IGF-1C hydrogel and ADSCs in ischemic kidneys ameliorated renal function, likely by the observed promotion of stem cell survival and angiogenesis, as visualized by bioluminescence imaging and attenuation of fibrosis. In conclusion, IGF-1C immobilized on a chitosan hydrogel provides an artificial microenvironment for ADSCs and may be a promising therapeutic approach for AKI. PMID:26869006

  11. Periodontal tissue regeneration using enzymatically solidified chitosan hydrogels with or without cell loading

    NARCIS (Netherlands)

    Yan, X.Z.; Beucken, J.J.J.P van den; Cai, X; Yu, N.; Jansen, J.A.; Yang, F.

    2015-01-01

    This study is aimed to evaluate the in vivo biocompatibility and periodontal regenerative potential of enzymatically solidified chitosan hydrogels with or without incorporated periodontal ligament cells (PDLCs). To this end, chitosan hydrogels, with (n=8; CHIT+CELL) or without (n=8; CHIT) fluorescen

  12. Design and performance of a sericin-alginate interpenetrating network hydrogel for cell and drug delivery

    OpenAIRE

    Yeshun Zhang; Jia Liu; Lei Huang; Zheng Wang; Lin Wang

    2015-01-01

    Although alginate hydrogels have been extensively studied for tissue engineering applications, their utilization is limited by poor mechanical strength, rapid drug release, and a lack of cell adhesive ability. Aiming to improve these properties, we employ the interpenetrating hydrogel design rationale. Using alginate and sericin (a natural protein with many unique properties and a major component of silkworm silk), we develop an interpenetrating polymer network (IPN) hydrogel comprising inter...

  13. Hydrogel surfaces to promote attachment and spreading of endothelial progenitor cells.

    Science.gov (United States)

    Camci-Unal, Gulden; Nichol, Jason William; Bae, Hojae; Tekin, Halil; Bischoff, Joyce; Khademhosseini, Ali

    2013-05-01

    Endothelialization of artificial vascular grafts is a challenging process in cardiovascular tissue engineering. Functionalized biomaterials could be promising candidates to promote endothelialization in repair of cardiovascular injuries. The purpose of this study was to synthesize hyaluronic acid (HA) and heparin-based hydrogels that could promote adhesion and spreading of endothelial progenitor cells (EPCs). We report that the addition of heparin into HA-based hydrogels provides an attractive surface for EPCs promoting spreading and the formation of an endothelial monolayer on the hydrogel surface. To increase EPC adhesion and spreading, we covalently immobilized CD34 antibody (Ab) on HA-heparin hydrogels, using standard EDC/NHS amine-coupling strategies. We found that EPC adhesion and spreading on CD34 Ab-immobilized HA-heparin hydrogels was significantly higher than their non-modified analogues. Once adhered, EPCs spread and formed an endothelial layer on both non-modified and CD34 Ab-modified HA-heparin hydrogels after 3 days of culture. We did not observe significant adhesion and spreading when heparin was not included in the control hydrogels. In addition to EPCs, we also used human umbilical cord vein endothelial cells (HUVECs), which adhered and spread on HA-heparin hydrogels. Macrophages exhibited significantly less adhesion compared to EPCs on the same hydrogels. This composite material could possibly be used to develop surface coatings for artificial cardiovascular implants, due to its specificity for EPC and endothelial cells on an otherwise non-thrombogenic surface. PMID:22223475

  14. Digital microfluidic three-dimensional cell culture and chemical screening platform using alginate hydrogels.

    Science.gov (United States)

    George, Subin M; Moon, Hyejin

    2015-03-01

    Electro wetting-on-dielectric (EWOD) digital microfluidics (DMF) can be used to develop improved chemical screening platforms using 3-dimensional (3D) cell culture. Alginate hydrogels are one common method by which a 3D cell culture environment is created. This paper presents a study of alginate gelation on EWOD DMF and investigates designs to obtain uniform alginate hydrogels that can be repeatedly addressed by any desired liquids. A design which allows for gels to be retained in place during liquid delivery and removal without using any physical barriers or hydrophilic patterning of substrates is presented. A proof of concept screening platform is demonstrated by examining the effects of different concentrations of a test chemical on 3D cells in alginate hydrogels. In addition, the temporal effects of the various chemical concentrations on different hydrogel posts are demonstrated, thereby establishing the benefits of an EWOD DMF 3D cell culture and chemical screening platform using alginate hydrogels. PMID:25945142

  15. Hydrogel-Based Nanocomposites and Mesenchymal Stem Cells: A Promising Synergistic Strategy for Neurodegenerative Disorders Therapy

    Directory of Open Access Journals (Sweden)

    Diego Albani

    2013-01-01

    Full Text Available Hydrogel-based materials are widely employed in the biomedical field. With regard to central nervous system (CNS neurodegenerative disorders, the design of injectable nanocomposite hydrogels for in situ drug or cell release represents an interesting and minimally invasive solution that might play a key role in the development of successful treatments. In particular, biocompatible and biodegradable hydrogels can be designed as specific injectable tools and loaded with nanoparticles (NPs, to improve and to tailor their viscoelastic properties upon injection and release profile. An intriguing application is hydrogel loading with mesenchymal stem cells (MSCs that are a very promising therapeutic tool for neurodegenerative or traumatic disorders of the CNS. This multidisciplinary review will focus on the basic concepts to design acellular and cell-loaded materials with specific and tunable rheological and functional properties. The use of hydrogel-based nanocomposites and mesenchymal stem cells as a synergistic strategy for nervous tissue applications will be then discussed.

  16. Viral infection of human progenitor and liver-derived cells encapsulated in three-dimensional PEG-based hydrogel

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Nam-Joon; Elazar, Menashe; Xiong, Anming; Glenn, Jeffrey S [Department of Medicine, Division of Gastroenterology and Hepatology, Stanford University School of Medicine, CCSR Building Room 3115A, 269 Campus Drive, Stanford, CA 94305 (United States); Lee, Wonjae [Mechanical Engineering, Stanford University, Stanford, CA 94305 (United States); Chiao, Eric; Baker, Julie [Department of Genetics, Stanford University School of Medicine, Stanford, CA 94305 (United States); Frank, Curtis W, E-mail: jeffrey.glenn@stanford.ed, E-mail: curt.frank@stanford.ed [Department of Chemical Engineering, Stanford University, Stanford, CA 94305 (United States)

    2009-02-15

    We have studied the encapsulation of human progenitor cells into 3D PEG hydrogels. Replication-incompetent lentivirus promoter reporter vectors were found to efficiently detect the in vivo expression of human hepatic genes in hydrogel-encapsulated liver progenitor cells. Similarly, hydrogel-encapsulated cells could be efficiently infected with hepatitis C virus, and progeny infectious virus could be recovered from the media supernatants of the hydrogels. Provocatively, the diameters of these virus particles range from {approx}50 to 100 nm, while the calculated mesh size of the 8 k hydrogel is 44.6 +- 1.7 A. To reconcile how viral particles can penetrate the hydrogels to infect the encapsulated cells, we propose that microfractures/defects of the hydrogel result in a functional pore size of up to 20 fold greater than predicted by theoretical mesh calculations. These results suggest a new model of hydrogel structure, and have exciting implications for tissue engineering and hepatitis virus studies. (communication)

  17. Thermal-Responsive Behavior of a Cell Compatible Chitosan/Pectin Hydrogel.

    Science.gov (United States)

    Birch, Nathan P; Barney, Lauren E; Pandres, Elena; Peyton, Shelly R; Schiffman, Jessica D

    2015-06-01

    Biopolymer hydrogels are important materials for wound healing and cell culture applications. While current synthetic polymer hydrogels have excellent biocompatibility and are nontoxic, they typically function as a passive matrix that does not supply any additional bioactivity. Chitosan (CS) and pectin (Pec) are natural polymers with active properties that are desirable for wound healing. Unfortunately, the synthesis of CS/Pec materials have previously been limited by harsh acidic synthesis conditions, which further restricted their use in biomedical applications. In this study, a zero-acid hydrogel has been synthesized from a mixture of chitosan and pectin at biologically compatible conditions. For the first time, we demonstrated that salt could be used to suppress long-range electrostatic interactions to generate a thermoreversible biopolymer hydrogel that has temperature-sensitive gelation. Both the hydrogel and the solution phases are highly elastic, with a power law index of close to -1. When dried hydrogels were placed into phosphate buffered saline solution, they rapidly rehydrated and swelled to incorporate 2.7× their weight. As a proof of concept, we removed the salt from our CS/Pec hydrogels, thus, creating thick and easy to cast polyelectrolyte complex hydrogels, which proved to be compatible with human marrow-derived stem cells. We suggest that our development of an acid-free CS/Pec hydrogel system that has excellent exudate uptake, holds potential for wound healing bandages. PMID:25932898

  18. Research on the use of hydrogel for the three-dimensional cell culture in microfluidic system

    Science.gov (United States)

    Tomecka, Ewelina; Jastrzebska, ElŻbieta; Chudy, Michał; Dybko, Artur

    2014-08-01

    This paper presents a possibility of use of hydrogel in microfluidic system, which can be a promising tool for threedimensional cell culture. In the research the commercially available self-assembling peptide hydrogel Puramatrix was used. Gelation of this hydrogel is initiated by the contact with culture medium. That's why it is critical that no salts or culture medium come in contact with this hydrogel until gelation is desired. The geometry of the designed microdevice enables hydrodynamic focusing of liquid hydrogel-cells mixture and then gelation of the mixture in the middle of the main microchannel due to the flow of the culture medium. As a sheath fluid sucrose solution was used. It provides also, in the first stage, isolation of culture medium (containing gelling salts) from liquid mixture of hydrogel and cells. When the flow of sucrose solution is turned off, the culture medium starts to be in contact to the hydrogel mixed with cell. As a result, simultaneously gelation of the hydrogel and encapsulation of cells in it are successfully achieved.

  19. Supramolecular hydrogelators of N-terminated dipeptides selectively inhibit cancer cells

    OpenAIRE

    Kuang, Yi; Gao, Yuan; Xu, Bing

    2011-01-01

    Consisting of N-terminated diphenylalanine, a new type of supramolecular hydrogelators forms hydrogels within a narrow pH window (pH 5.0 to 6.0) and selectively inhibits growth of HeLa cells, which provides important and useful insights for designing molecular nanofibers as potential nanomedicines.

  20. Supramolecular hydrogelators of N-terminated dipeptides selectively inhibit cancer cells.

    Science.gov (United States)

    Kuang, Yi; Gao, Yuan; Xu, Bing

    2011-12-21

    Consisting of N-terminated diphenylalanine, a new type of supramolecular hydrogelators forms hydrogels within a narrow pH window (pH 5.0 to 6.0) and selectively inhibits growth of HeLa cells, which provides important and useful insights for designing molecular nanofibers as potential nanomedicines. PMID:22037699

  1. Effects of cellular parameters on the in vitro osteogenic potential of dual-gelling mesenchymal stem cell-laden hydrogels.

    Science.gov (United States)

    Vo, Tiffany N; Tabata, Yasuhiko; Mikos, Antonios G

    2016-08-01

    This work investigated the effects of cellular encapsulation density and differentiation stage on the osteogenic capacity of injectable, dual physically and chemically gelling hydrogels comprised of thermogelling macromers and polyamidoamine crosslinkers. Undifferentiated and osteogenically predifferentiated mesenchymal stem cells (MSCs) were encapsulated within 20 wt% composite hydrogels with gelatin microparticles at densities of six or 15 million cells/mL. We hypothesized that a high encapsulation density and predifferentiation would promote increased cellular interaction and accelerate osteogenesis, leading to enhanced osteogenic potential in vitro. Hydrogels were able to maintain the viability of the encapsulated cells over a period of 28 days, with the high encapsulation density and predifferentiation group possessing the highest DNA content at all time points. Early alkaline phosphatase activity and mineralization were promoted by encapsulation density, whereas this effect by predifferentiation was only observed in the low seeding density groups. Both parameters only demonstrated short-lived effects when examined independently, but jointly led to greater levels of alkaline phosphatase activity and mineralization. The combined effects suggest that there may be optimal encapsulation densities and differentiation periods that need to be investigated to improve MSCs for biomaterial-based therapeutics in bone tissue engineering. PMID:27328947

  2. Improved cartilage repair via in vitro pre-maturation of MSC-seeded hyaluronic acid hydrogels

    International Nuclear Information System (INIS)

    Functional repair of focal cartilage defects requires filling the space with neotissue that has compressive properties comparable to native tissue and integration with adjacent host cartilage. While poor integration is a common complication with current clinical treatments, reports of tissue engineering advances in the development of functional compressive properties rarely include analyses of their potential for integration. Our objective was thus to assess both the maturation and integration of mesenchymal stem cell (MSC)-laden hyaluronic acid (HA) hydrogels in an in vitro cartilage defect model. Furthermore, we considered the effects of an initial period of pre-maturation as well as various material formulations to maximize both construct compressive properties and integration strength. MSCs were encapsulated in 1%, 3% and 5% methacrylated HA (MeHA) or 2% agarose (Ag) and gelled directly (in situ) within an in vitro cartilage defect or were formed and then pre-cultured for 4 weeks before implantation. Results showed that the integration strength of pre-cultured repair constructs was equal to (1% MeHA) or greater than (2% Ag) the integration of in situ repaired cartilage. Moreover, MSC chondrogenesis and maturation was restricted by the in situ repair environment with constructs maturing to a much lesser extent than pre-matured constructs. These results indicate that construct pre-maturation may be an essential element of functional cartilage repair. (paper)

  3. Biocompatible fluorescent supramolecular nanofibrous hydrogel for long-term cell tracking and tumor imaging applications

    Science.gov (United States)

    Wang, Huaimin; Mao, Duo; Wang, Youzhi; Wang, Kai; Yi, Xiaoyong; Kong, Deling; Yang, Zhimou; Liu, Qian; Ding, Dan

    2015-11-01

    Biocompatible peptide-based supramolecular hydrogel has recently emerged as a new and promising system for biomedical applications. In this work, Rhodamine B is employed as a new capping group of self-assembling peptide, which not only provides the driving force for supramolecular nanofibrous hydrogel formation, but also endows the hydrogel with intrinsic fluroescence signal, allowing for various bioimaging applications. The fluorescent peptide nanofibrous hydrogel can be formed via disulfide bond reduction. After dilution of the hydrogel with aqueous solution, the fluorescent nanofiber suspension can be obtained. The resultant nanofibers are able to be internalized by the cancer cells and effectively track the HeLa cells for as long as 7 passages. Using a tumor-bearing mouse model, it is also demonstrated that the fluorescent supramolecular nanofibers can serve as an efficient probe for tumor imaging in a high-contrast manner.

  4. Hydrogels with tunable stress relaxation regulate stem cell fate and activity

    Science.gov (United States)

    Chaudhuri, Ovijit; Gu, Luo; Klumpers, Darinka; Darnell, Max; Bencherif, Sidi A.; Weaver, James C.; Huebsch, Nathaniel; Lee, Hong-Pyo; Lippens, Evi; Duda, Georg N.; Mooney, David J.

    2016-03-01

    Natural extracellular matrices (ECMs) are viscoelastic and exhibit stress relaxation. However, hydrogels used as synthetic ECMs for three-dimensional (3D) culture are typically elastic. Here, we report a materials approach to tune the rate of stress relaxation of hydrogels for 3D culture, independently of the hydrogel's initial elastic modulus, degradation, and cell-adhesion-ligand density. We find that cell spreading, proliferation, and osteogenic differentiation of mesenchymal stem cells (MSCs) are all enhanced in cells cultured in gels with faster relaxation. Strikingly, MSCs form a mineralized, collagen-1-rich matrix similar to bone in rapidly relaxing hydrogels with an initial elastic modulus of 17 kPa. We also show that the effects of stress relaxation are mediated by adhesion-ligand binding, actomyosin contractility and mechanical clustering of adhesion ligands. Our findings highlight stress relaxation as a key characteristic of cell-ECM interactions and as an important design parameter of biomaterials for cell culture.

  5. Osteogenic differentiation of human mesenchymal stem cells promotes mineralization within a biodegradable peptide hydrogel

    Science.gov (United States)

    Castillo Diaz, Luis A; Elsawy, Mohamed; Saiani, Alberto; Gough, Julie E; Miller, Aline F

    2016-01-01

    An attractive strategy for the regeneration of tissues has been the use of extracellular matrix analogous biomaterials. Peptide-based fibrillar hydrogels have been shown to mimic the structure of extracellular matrix offering cells a niche to undertake their physiological functions. In this study, the capability of an ionic-complementary peptide FEFEFKFK (F, E, and K are phenylalanine, glutamic acid, and lysine, respectively) hydrogel to host human mesenchymal stem cells in three dimensions and induce their osteogenic differentiation is demonstrated. Assays showed sustained cell viability and proliferation throughout the hydrogel over 12 days of culture and these human mesenchymal stem cells differentiated into osteoblasts simply upon addition of osteogenic stimulation. Differentiated osteoblasts synthesized key bone proteins, including collagen-1 (Col-1), osteocalcin, and alkaline phosphatase. Moreover, mineralization occurred within the hydrogel. The peptide hydrogel is a naturally biodegradable material as shown by oscillatory rheology and reversed-phase high-performance liquid chromatography, where both viscoelastic properties and the degradation of the hydrogel were monitored over time, respectively. These findings demonstrate that a biodegradable octapeptide hydrogel can host and induce the differentiation of stem cells and has the potential for the regeneration of hard tissues such as alveolar bone. PMID:27493714

  6. A flexible micro biofuel cell utilizing hydrogel containing ascorbic acid

    International Nuclear Information System (INIS)

    This paper reports on a biofuel cell with a dimension of 13×24 mm2 fabricated on a flexible polyimide substrate. I its porous carbon-coated platinum (Pt) electrodes of 3 mm in width and 10 mm in length were fabricated using photolithography and screen printing techniques. Porous carbon was deposited by screen printing of carbon black ink on the Pt electrode surfaces in order to increase the effective electrode surface area and to absorb more enzymes on the electrode surfaces. It utilizes a solidified ascorbic acid (AA) aqueous solution in an agarose hydrogel to increase the portability. The maximum power and power density for the biofuel cell with the fuel unit containing 100 mM AA were 0.063 μW and 0.21 μW/cm2 at 0.019 V, respectively

  7. Nanofiber density determines endothelial cell behavior on hydrogel matrix

    International Nuclear Information System (INIS)

    When cultured under static conditions, bacterial cellulose pellicles, by the nature of the polymer synthesis that involves molecular oxygen, are characterized by two distinct surface sides. The upper surface is denser in fibers (entangled) than the lower surface that shows greater surface porosity. Human umbilical vein endothelial cells (HUVECs) were used to exploit how the microarchitecture (i.e., surface porosity, fiber network structure, surface topology, and fiber density) of bacterial cellulose pellicle surfaces influence cell–biomaterial interaction and therefore cell behavior. Adhesion, cell ingrowth, proliferation, viability and cell death mechanisms were evaluated on the two pellicle surface sides. Cell behavior, including secondary necrosis, is influenced only by the microarchitecture of the surface, since the biomaterial is extremely pure (constituted of cellulose and water only). Cell–cellulose fiber interaction is the determinant signal in the cell–biomaterial responses, isolated from other frequently present interferences such as protein and other chemical traces usually present in cell culture matrices. Our results suggest that microarchitecture of hydrogel materials might determine the performance of biomedical products, such as bacterial cellulose tissue engineering constructs (BCTECs). - Highlights: • Topography of BC pellicle is relevant to determine endothelial cells' fate. • Cell–biomaterial response is affected by the topography of BC-pellicle surface. • Endothelial cells exhibit different behavior depending on the BC topography. • Apoptosis and necrosis of endothelial cells were affected by the BC topography

  8. Nanofiber density determines endothelial cell behavior on hydrogel matrix

    Energy Technology Data Exchange (ETDEWEB)

    Berti, Fernanda V., E-mail: fernanda@intelab.ufsc.br [Department of Chemical and Food Engineering, Federal University of Santa Catarina, 88040-900 Florianópolis, SC (Brazil); Rambo, Carlos R. [Department of Electrical Engineering, Federal University of Santa Catarina, 88040-900 Florianópolis, SC (Brazil); Dias, Paulo F. [Department of Cell Biology, Embryology and Genetics, Federal University of Santa Catarina, 88040-900 Florianópolis, SC (Brazil); Porto, Luismar M. [Department of Chemical and Food Engineering, Federal University of Santa Catarina, 88040-900 Florianópolis, SC (Brazil)

    2013-12-01

    When cultured under static conditions, bacterial cellulose pellicles, by the nature of the polymer synthesis that involves molecular oxygen, are characterized by two distinct surface sides. The upper surface is denser in fibers (entangled) than the lower surface that shows greater surface porosity. Human umbilical vein endothelial cells (HUVECs) were used to exploit how the microarchitecture (i.e., surface porosity, fiber network structure, surface topology, and fiber density) of bacterial cellulose pellicle surfaces influence cell–biomaterial interaction and therefore cell behavior. Adhesion, cell ingrowth, proliferation, viability and cell death mechanisms were evaluated on the two pellicle surface sides. Cell behavior, including secondary necrosis, is influenced only by the microarchitecture of the surface, since the biomaterial is extremely pure (constituted of cellulose and water only). Cell–cellulose fiber interaction is the determinant signal in the cell–biomaterial responses, isolated from other frequently present interferences such as protein and other chemical traces usually present in cell culture matrices. Our results suggest that microarchitecture of hydrogel materials might determine the performance of biomedical products, such as bacterial cellulose tissue engineering constructs (BCTECs). - Highlights: • Topography of BC pellicle is relevant to determine endothelial cells' fate. • Cell–biomaterial response is affected by the topography of BC-pellicle surface. • Endothelial cells exhibit different behavior depending on the BC topography. • Apoptosis and necrosis of endothelial cells were affected by the BC topography.

  9. Light-guiding hydrogels for cell-based sensing and optogenetic synthesis in vivo

    Science.gov (United States)

    Choi, Myunghwan; Choi, Jin Woo; Kim, Seonghoon; Nizamoglu, Sedat; Hahn, Sei Kwang; Yun, Seok Hyun

    2013-12-01

    Polymer hydrogels are widely used as cell scaffolds for biomedical applications. Although the biochemical and biophysical properties of hydrogels have been investigated extensively, little attention has been paid to their potential photonic functionalities. Here, we report cell-integrated polyethylene glycol-based hydrogels for in vivo optical-sensing and therapy applications. Hydrogel patches containing cells were implanted in awake, freely moving mice for several days and shown to offer long-term transparency, biocompatibility, cell viability and light-guiding properties (loss of improved glucose homeostasis. Furthermore, real-time optical readout of encapsulated heat-shock-protein-coupled fluorescent reporter cells made it possible to measure the nanotoxicity of cadmium-based bare and shelled quantum dots (CdTe; CdSe/ZnS) in vivo.

  10. A Drosera-bioinspired hydrogel for catching and killing cancer cells.

    Science.gov (United States)

    Li, Shihui; Chen, Niancao; Gaddes, Erin R; Zhang, Xiaolong; Dong, Cheng; Wang, Yong

    2015-01-01

    A variety of bioinspired materials have been successfully synthesized to mimic the sophisticated structures or functions of biological systems. However, it is still challenging to develop materials with multiple functions that can be performed synergistically or sequentially. The purpose of this work was to demonstrate a novel bioinspired hydrogel that can interact with cancer cells, functionally similar to Drosera in catching and killing prey. This hydrogel had two layers with the top one functionalized with oligonucleotide aptamers and the bottom one functionalized with double-stranded DNA. The results show that the top hydrogel layer was able to catch target cells with high efficiency and specificity, and that the bottom hydrogel layer could sequester doxorubicin (Dox) for sustained drug release. Importantly, the released Dox could kill 90% of the cells after 1-h residence of the cells on the hydrogel. After the cell release, this bifunctional hydrogel could be regenerated for continuous cell catching and killing. Therefore, the data presented in this study has successfully demonstrated the potential of developing a material system with the functions of attracting, catching and killing diseased cells (e.g., circulating tumor cells) or even invading microorganisms (e.g., bacteria). PMID:26396063

  11. pH-Sensitive and Thermosensitive Hydrogels as Stem-Cell Carriers for Cardiac Therapy.

    Science.gov (United States)

    Li, Zhenqing; Fan, Zhaobo; Xu, Yanyi; Lo, Wilson; Wang, Xi; Niu, Hong; Li, Xiaofei; Xie, Xiaoyun; Khan, Mahmood; Guan, Jianjun

    2016-05-01

    Stem-cell therapy has the potential to regenerate damaged heart tissue after a heart attack. Injectable hydrogels may be used as stem-cell carriers to improve cell retention in the heart tissue. However, current hydrogels are not ideal to serve as cell carriers because most of them block blood vessels after solidification. In addition, these hydrogels have a relatively slow gelation rate (typically >60 s), which does not allow them to quickly solidify upon injection, so as to efficiently hold cells in the heart tissue. As a result, the hydrogels and cells are squeezed out of the tissue, leading to low cell retention. To address these issues, we have developed hydrogels that can quickly solidify at the pH of an infarcted heart (6-7) at 37 °C but cannot solidify at the pH of blood (7.4) at 37 °C. These hydrogels are also clinically attractive because they can be injected through catheters commonly used for minimally invasive surgeries. The hydrogels were synthesized by free-radical polymerization of N-isopropylacrylamide, propylacrylic acid, hydroxyethyl methacrylate-co-oligo(trimethylene carbonate), and methacrylate poly(ethylene oxide) methoxy ester. Hydrogel solutions were injectable through 0.2-mm-diameter catheters at pH 8.0 at 37 °C, and they can quickly form solid gels under pH 6.5 at 37 °C. All of the hydrogels showed pH-dependent degradation and mechanical properties with less mass loss and greater complex shear modulus at pH 6.5 than at pH 7.4. When cardiosphere-derived cells (CDCs) were encapsulated in the hydrogels, the cells were able to survive during a 7-day culture period. The surviving cells were differentiated into cardiac cells, as evidenced by the expression of cardiac markers at both the gene and protein levels, such as cardiac troponin T, myosin heavy chain α, calcium channel CACNA1c, cardiac troponin I, and connexin 43. The gel integrity was found to largely affect CDC cardiac differentiation. These results suggest that the developed dual

  12. The role of matrix metalloproteinases in regulating neuronal and nonneuronal cell invasion into PEGylated fibrinogen hydrogels.

    Science.gov (United States)

    Sarig-Nadir, Offra; Seliktar, Dror

    2010-09-01

    Injured peripheral nerve tissue could benefit from biomaterial nerve guidance conduits (NGCs) that are designed to promote neuronal regeneration. Nerve regeneration is a complex multi-step process that involves the remodeling of the ECM surrounding the regenerating neural tissue. Hydrogel biomaterials have been used as provisional matrices to regulate this regeneration process by providing the desired physical properties and controllable degradation characteristics. The purpose of this investigation was to understand the mechanism by which nerve cells penetrate into a hydrogel made from PEGylated fibrinogen. In this context, the dorsal root ganglion (DRG) assay was used as an in vitro model to study the cellular invasion behavior of both neural and nonneuronal cells. Our hypothesis stipulated that DRG cells employ matrix metalloproteinases (MMPs) in order to degrade the dense hydrogel matrix and penetrate the biomaterial. Three dimensional (3D) DRG-hydrogel constructs were cultured with MMP inhibitors (MMPi) and the effect of the inhibitors on DRG cell outgrowth was investigated. We also examined the effect of inhibitors on two dimensional (2D) DRG cell outgrowth on PEGylated fibrinogen hydrogels and on tissue culture polystyrene (TCP). Our results demonstrate that DRG cell outgrowth into and onto PEGylated fibrinogen hydrogels was inhibited by MMPi and that the outgrowth characteristics was dependent on the type of inhibitor and its concentration. MMP-3i and MMP-8i decreased both neuronal and nonneuronal outgrowth, where MMP-3i had a stronger inhibitory effect on nonneuronal cells. MMP-2/9i, on the other hand, affected the neuronal outgrowth much more than the others. We concluded that MMPs play a central role in the process of DRG cell penetration into PEGylated fibrinogen hydrogels and may also regulate the adhesion, migration and elongation of neuronal cells on the surface of these hydrogel biomaterials. PMID:20537384

  13. Tough and elastic hydrogel of hyaluronic acid and chondroitin sulfate as potential cell scaffold materials.

    Science.gov (United States)

    Ni, Yilu; Tang, Zhurong; Cao, Wanxu; Lin, Hai; Fan, Yujiang; Guo, Likun; Zhang, Xingdong

    2015-03-01

    Natural polysaccharides are extensively investigated as cell scaffold materials for cellular adhesion, proliferation, and differentiation due to their excellent biocompatibility, biodegradability, and biofunctions. However, their application is often severely limited by their mechanical behavior. In this study, a tough and elastic hydrogel scaffold was prepared with hyaluronic acid (HA) and chondroitin sulfate (CS). HA and CS were conjugated with tyramine (TA) and the degree of substitution (DS) was 10.7% and 11.3%, respectively, as calculated by (1)H NMR spectra. The hydrogel was prepared by mixing HA-TA and CS-TA in presence of H2O2 and HRP. The sectional morphology of hydrogels was observed by SEM, static and dynamic mechanical properties were analyzed by Shimadzu electromechanical testing machine and dynamic mechanical thermal analyzer Q800. All samples showed good ability to recover their appearances after deformation, the storage modulus (E') of hydrogels became higher as the testing frequency went up. Hydrogels also showed fatigue resistance to cyclic compression. Mesenchymal stem cells encapsulated in hydrogels showed good cell viability as detected by CLSM. This study suggests that the hydrogels have both good mechanical properties and biocompatibility, and may serve as model systems to explore mechanisms of deformation and energy dissipation or find some applications in tissue engineering. PMID:25445680

  14. Stem Cell Derived Extracellular Matrix Enables Survival and Multi Lineage Differentiation within Superporous Hydrogels

    OpenAIRE

    Köllmer, Melanie; Keskar, Vandana; Hauk, Thomas G.; Collins, John M.; Russell, Brenda; Gemeinhart, Richard A.

    2012-01-01

    Hydrophilic poly(ethylene glycol) diacrylate (PEGDA) hydrogel surfaces resist protein adsorption and are generally thought to be unsuitable for anchorage dependent cells to adhere. Intriguingly, our previous findings revealed that PEGDA superporous hydrogel scaffolds (SPHs) allow anchorage of bone marrow derived human mesenchymal stem cells (hMSCs) and support their long term survival. Therefore, we hypothesized that the physicochemical characteristics of the scaffold impart properties that c...

  15. Differential effect of hypoxia on human mesenchymal stem cell chondrogenesis and hypertrophy in hyaluronic acid hydrogels.

    Science.gov (United States)

    Zhu, Meiling; Feng, Qian; Bian, Liming

    2014-03-01

    Photocrosslinked hyaluronic acid (HA) hydrogels provide a conducive 3-D environment that supports the chondrogenesis of human mesenchymal stem cells (hMSCs). The HA macromer concentration in the hydrogels has a significant impact on the chondrogenesis of the encapsulated MSCs due to changes in the physical properties of the hydrogels. Meanwhile, hypoxia has been shown to promote MSC chondrogenesis and suppress subsequent hypertrophy. This study investigates the combinatorial effect of tuning HA macromer concentration (1.5-5%w/v) and hypoxia on MSC chondrogenesis and hypertrophy. To decouple the effect of HA concentration from that of crosslinking density, the HA hydrogel crosslinking density was adjusted by varying the extent of the reaction through the light exposure time while keeping the HA concentration constant (5%w/v at 5 or 15 min). It was found that hypoxia had no significant effect on the chondrogenesis and cartilaginous matrix synthesis of hMSCs under all hydrogel conditions. In contrast, the hypoxia-mediated positive or negative regulation of hMSC hypertrophy in HA hydrogels is dependent on the HA concentration but independent of the crosslinking density. Specifically, hypoxia significantly suppressed hMSC hypertrophy and neocartilage calcification in low HA concentration hydrogels, whereas hypoxia substantially enhanced hMSC hypertrophy, leading to elevated tissue calcification in high HA concentration hydrogels irrespective of their crosslinking density. In addition, at a constant high HA concentration, increasing hydrogel crosslinking density promoted hMSC hypertrophy and matrix calcification. To conclude, the findings from this study demonstrate that the effect of hypoxia on hMSC chondrogenesis and hypertrophy is differentially influenced by the encapsulating HA hydrogel properties. PMID:24342044

  16. Controlled release of simvastatin from in situ forming hydrogel triggers bone formation in MC3T3-E1 cells.

    Science.gov (United States)

    Park, Yoon Shin; David, Allan E; Park, Kyung Min; Lin, Chia-Ying; Than, Khoi D; Lee, Kyuri; Park, Jun Beom; Jo, Inho; Park, Ki Dong; Yang, Victor C

    2013-04-01

    Simvastatin (SIM), a drug commonly administered for the treatment of hypercholesterolemia, has been recently reported to induce bone regeneration/formation. In this study, we investigated the properties of hydrogel composed of gelatin-poly(ethylene glycol)-tyramine (GPT) as an efficient SIM delivery vehicle that can trigger osteogenic differentiation. Sustained delivery of SIM was achieved through its encapsulation in an injectable, biodegradable GPT-hydrogel. Cross-linking of the gelatin-based GPT-hydrogel was induced by the reaction of horse radish peroxidase and H(2)O(2). GPT-hydrogels of three different matrix stiffness, 1,800 (GPT-hydrogel1), 5,800 (GPT-hydrogel2), and 8,400 Pa (GPT-hydrogel3) were used. The gelation/degradation time and SIM release profiles of hydrogels loaded with two different concentrations of SIM, 1 and 3 mg/ml, were also evaluated. Maximum swelling times of GPT-hydrogel1, GPT-hydrogel2, and GPT-hydrogel3 were observed to be 6, 12, and 20 days, respectively. All GPT-hydrogels showed complete degradation within 55 days. The in vitro SIM release profiles, investigated in PBS buffer (pH 7.4) at 37°C, exhibited typical biphasic release patterns with the initial burst being more rapid with GPT-hydrogel1 compared with GPT-hydrogel3. Substantial increase in matrix metalloproteinase-13, osteocalcin expression levels, and mineralization were seen in osteogenic differentiation system using MC3T3-E1 cells cultured with GPT-hydrogels loaded with SIM in a dose-dependent manner. This study demonstrated that controlled release of SIM from a biodegradable, injectable GPT-hydrogel had a promising role for long-term treatment of chronic degenerative diseases such as disc degenerative disease. PMID:23250670

  17. Cell Growth and Desorption on the Surface of Temperature-sensitive Semi-IPNs Hydrogels Based on Silk Sericin

    Institute of Scientific and Technical Information of China (English)

    LI Xuewei; ZHANG Qingsong; CHEN Li; ZHANG Rui; GUO Gang

    2012-01-01

    Semi-interpenetrating (semi-IPNs) hydrogels containing biocompatible silk sericin (SS)and poly(N-isopropylacrylamide)(PNIPAM) were prepared as novel cellular matrices.Their maximum swelling degree and basic characteristics for biomedical applications such as mouse fibroblasts (L929) cell proliferation and desorption were investigated.The results showed that the incorporation of high hydrophilic SS into PNIPAM hydrogel increased the maximum swelling degree of the semi-IPNs hydrogels,and the adhesion and growth of the L929 on semi-IPNs hydrogels were at least comparable to,or even better than,that on conventional PNIPAM hydrogel.In addition,L929 cells were found to detach from the hydrogels surface naturally by controlling environmental temperature.These results suggest great potential of semi-IPNs hydrogels in tissue engineering.

  18. Bioprinting Organotypic Hydrogels with Improved Mesenchymal Stem Cell Remodeling and Mineralization Properties for Bone Tissue Engineering.

    Science.gov (United States)

    Duarte Campos, Daniela Filipa; Blaeser, Andreas; Buellesbach, Kate; Sen, Kshama Shree; Xun, Weiwei; Tillmann, Walter; Fischer, Horst

    2016-06-01

    3D-manufactured hydrogels with precise contours and biological adhesion motifs are interesting candidates in the regenerative medicine field for the culture and differentiation of human bone-marrow-derived mesenchymal stem cells (MSCs). 3D-bioprinting is a powerful technique to approach one step closer the native organization of cells. This study investigates the effect of the incorporation of collagen type I in 3D-bioprinted polysaccharide-based hydrogels to the modulation of cell morphology, osteogenic remodeling potential, and mineralization. By combining thermo-responsive agarose hydrogels with collagen type I, the mechanical stiffness and printing contours of printed constructs can be improved compared to pure collagen hydrogels which are typically used as standard materials for MSC osteogenic differentiation. The results presented here show that MSC not only survive the 3D-bioprinting process but also maintain the mesenchymal phenotype, as proved by live/dead staining and immunocytochemistry (vimentin positive, CD34 negative). Increased solids concentrations of collagen in the hydrogel blend induce changes in cell morphology, namely, by enhancing cell spreading, that ultimately contribute to enhanced and directed MSC osteogenic differentiation. 3D-bioprinted agarose-collagen hydrogels with high-collagen ratio are therefore feasible for MSC osteogenic differentiation, contrarily to low-collagen blends, as proved by two-photon microscopy, Alizarin Red staining, and real-time polymerase chain reaction. PMID:27072652

  19. 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

  20. QHREDGS enhances tube formation, metabolism and survival of endothelial cells in collagen-chitosan hydrogels.

    Directory of Open Access Journals (Sweden)

    Jason W Miklas

    Full Text Available Cell survival in complex, vascularized tissues, has been implicated as a major bottleneck in advancement of therapies based on cardiac tissue engineering. This limitation motivates the search for small, inexpensive molecules that would simultaneously be cardio-protective and vasculogenic. Here, we present peptide sequence QHREDGS, based upon the fibrinogen-like domain of angiopoietin-1, as a prime candidate molecule. We demonstrated previously that QHREDGS improved cardiomyocyte metabolism and mitigated serum starved apoptosis. In this paper we further demonstrate the potency of QHREDGS in its ability to enhance endothelial cell survival, metabolism and tube formation. When endothelial cells were exposed to the soluble form of QHREDGS, improvements in endothelial cell barrier functionality, nitric oxide production and cell metabolism (ATP levels in serum starved conditions were found. The functionality of the peptide was then examined when conjugated to collagen-chitosan hydrogel, a potential carrier for in vivo application. The presence of the peptide in the hydrogel mitigated paclitaxel induced apoptosis of endothelial cells in a dose dependent manner. Furthermore, the peptide modified hydrogels stimulated tube-like structure formation of encapsulated endothelial cells. When integrin αvβ3 or α5β1 were antibody blocked during cell encapsulation in peptide modified hydrogels, tube formation was abolished. Therefore, the dual protective nature of the novel peptide QHREDGS may position this peptide as an appealing augmentation for collagen-chitosan hydrogels that could be used for biomaterial delivered cell therapies in the settings of myocardial infarction.

  1. QHREDGS enhances tube formation, metabolism and survival of endothelial cells in collagen-chitosan hydrogels.

    Science.gov (United States)

    Miklas, Jason W; Dallabrida, Susan M; Reis, Lewis A; Ismail, Nesreen; Rupnick, Maria; Radisic, Milica

    2013-01-01

    Cell survival in complex, vascularized tissues, has been implicated as a major bottleneck in advancement of therapies based on cardiac tissue engineering. This limitation motivates the search for small, inexpensive molecules that would simultaneously be cardio-protective and vasculogenic. Here, we present peptide sequence QHREDGS, based upon the fibrinogen-like domain of angiopoietin-1, as a prime candidate molecule. We demonstrated previously that QHREDGS improved cardiomyocyte metabolism and mitigated serum starved apoptosis. In this paper we further demonstrate the potency of QHREDGS in its ability to enhance endothelial cell survival, metabolism and tube formation. When endothelial cells were exposed to the soluble form of QHREDGS, improvements in endothelial cell barrier functionality, nitric oxide production and cell metabolism (ATP levels) in serum starved conditions were found. The functionality of the peptide was then examined when conjugated to collagen-chitosan hydrogel, a potential carrier for in vivo application. The presence of the peptide in the hydrogel mitigated paclitaxel induced apoptosis of endothelial cells in a dose dependent manner. Furthermore, the peptide modified hydrogels stimulated tube-like structure formation of encapsulated endothelial cells. When integrin αvβ3 or α5β1 were antibody blocked during cell encapsulation in peptide modified hydrogels, tube formation was abolished. Therefore, the dual protective nature of the novel peptide QHREDGS may position this peptide as an appealing augmentation for collagen-chitosan hydrogels that could be used for biomaterial delivered cell therapies in the settings of myocardial infarction. PMID:24013716

  2. Hydrogel Surfaces to Promote Attachment and Spreading of Endothelial Progenitor Cells

    OpenAIRE

    Camci-Unal, Gulden; Nichol, Jason William; Bae, Hojae; Tekin, Halil; Bischoff, Joyce; Khademhosseini, Ali

    2012-01-01

    Endothelialization of artificial vascular grafts is a challenging process in cardiovascular tissue engineering. Functionalized biomaterials could be promising candidates to promote endothelialization in repair of cardiovascular injuries. The purpose of this study was to synthesize hyaluronic acid (HA) and heparin based hydrogels that could promote adhesion and spreading of endothelial progenitor cells (EPCs). We report that the addition of heparin into HA-based hydrogels provides an attractiv...

  3. Photoinitiator-Free Synthesis of Endothelial Cell Adhesive and Enzymatically Degradable Hydrogels

    OpenAIRE

    Jones, Derek R.; Marchant, Roger E.; von Recum, Horst; Gupta, Anirban Sen; Kottke-Marchant, Kandice

    2014-01-01

    We report on a photoinitiator-free synthetic method of incorporating bioactivity into poly(ethylene glycol) (PEG) hydrogels in order to control physical properties, enzymatic biodegradability and cell-specific adhesiveness of the polymer network, while eliminating the need for UV-mediated photopolymerization. To accomplish this, hydrogel networks were polymerized using Michael addition with four-arm PEG acrylate (10 kDa), using a collagenase sensitive peptide (CSP) as a crosslinker, and intro...

  4. A Drosera-bioinspired hydrogel for catching and killing cancer cells

    OpenAIRE

    Shihui Li; Niancao Chen; Gaddes, Erin R.; Xiaolong Zhang; Cheng Dong; Yong Wang

    2015-01-01

    A variety of bioinspired materials have been successfully synthesized to mimic the sophisticated structures or functions of biological systems. However, it is still challenging to develop materials with multiple functions that can be performed synergistically or sequentially. The purpose of this work was to demonstrate a novel bioinspired hydrogel that can interact with cancer cells, functionally similar to Drosera in catching and killing prey. This hydrogel had two layers with the top one fu...

  5. Stiffness and Adhesivity Control Aortic Valve Interstitial Cell Behavior within Hyaluronic Acid Based Hydrogels

    OpenAIRE

    Duan, Bin; Hockaday, Laura A.; Kapetanovic, Edi; Kang, Kevin H.; Butcher, Jonathan T.

    2013-01-01

    Bioactive and biodegradable hydrogels that mimic the extracellular matrix and regulate valve interstitial cells (VIC) behavior are of great interest as three dimensional (3D) model systems for understanding mechanisms of valvular heart disease pathogenesis in vitro and the basis for regenerative templates for tissue engineering. However, the role of stiffness and adhesivity of hydrogels in VIC behavior remains poorly understood. This study reports synthesis of oxidized and methacrylated hyalu...

  6. Mesenchymal stem cell-laden anti-inflammatory hydrogel enhances diabetic wound healing

    OpenAIRE

    Shixuan Chen; Junbin Shi; Min Zhang; Yinghua Chen; Xueer Wang; Lei Zhang; Zhihui Tian; Yuan Yan; Qinglin Li; Wen Zhong; Malcolm Xing; Lu Zhang; Lin Zhang

    2015-01-01

    The purpose of this study was to permit bone marrow mesenchymal stem cells (BMSCs) to reach their full potential in the treatment of chronic wounds. A biocompatible multifunctional crosslinker based temperature sensitive hydrogel was developed to deliver BMSCs, which improve the chronic inflammation microenvironments of wounds. A detailed in vitro investigation found that the hydrogel is suitable for BMSC encapsulation and can promote BMSC secretion of TGF-β1 and bFGF. In vivo, full-thickness...

  7. Photoinitiator-free synthesis of endothelial cell-adhesive and enzymatically degradable hydrogels.

    Science.gov (United States)

    Jones, Derek R; Marchant, Roger E; von Recum, Horst; Sen Gupta, Anirban; Kottke-Marchant, Kandice

    2015-02-01

    We report on a photoinitiator-free synthetic method of incorporating bioactivity into poly(ethylene glycol) (PEG) hydrogels in order to control physical properties, enzymatic biodegradability and cell-specific adhesiveness of the polymer network, while eliminating the need for UV-mediated photopolymerization. To accomplish this, hydrogel networks were polymerized using Michael addition with four-arm PEG acrylate (10 kDa), using a collagenase-sensitive peptide (CSP) as a crosslinker, and introducing an endothelial cell-adhesive peptide either terminally (RGD) or attached to the crosslinking peptide sequence (CSP-RGD). The efficiency of the Michael addition reactions were determined by nuclear magnetic resonance and Ellman's assay. Successful decoupling of cell adhesivity and physical properties was demonstrated by quantifying and comparing the swelling ratios and Young's moduli of various hydrogel formulations. Degradation profiles were established by incubating functionalized hydrogels in collagenase solutions (0.0-1.0 μg ml(-1)), demonstrating that functionalized hydrogels degraded at a rate dependent upon collagenase concentration. Moreover, it was shown that the degradation rate was independent of CSP-RGD concentration. Cell attachment and proliferation on functionalized hydrogels were compared for various RGD concentrations, providing evidence that cell attachment and proliferation were directly related to relative amounts of the CSP-RGD combination peptide. An increase in cell viability was achieved using Michael addition techniques when compared to UV polymerization, and was assessed by a LIVE/DEAD fluorescence assay. This photoinitiator-free method shows promise in creating hydrogel-based tissue engineering scaffolds allow for decoupled cell adhesivity and physical properties and that render greater cell viability. PMID:25462848

  8. Self-assembled peptide-based hydrogels as scaffolds for anchorage-dependent cells.

    Science.gov (United States)

    Zhou, Mi; Smith, Andrew M; Das, Apurba K; Hodson, Nigel W; Collins, Richard F; Ulijn, Rein V; Gough, Julie E

    2009-05-01

    We report here the design of a biomimetic nanofibrous hydrogel as a 3D-scaffold for anchorage-dependent cells. The peptide-based bioactive hydrogel is formed through molecular self-assembly and the building blocks are a mixture of two aromatic short peptide derivatives: Fmoc-FF (Fluorenylmethoxycarbonyl-diphenylalanine) and Fmoc-RGD (arginine-glycine-aspartate) as the simplest self-assembling moieties reported so far for the construction of small-molecule-based bioactive hydrogels. This hydrogel provides a highly hydrated, stiff and nanofibrous hydrogel network that uniquely presents bioactive ligands at the fibre surface; therefore it mimics certain essential features of the extracellular matrix. The RGD sequence as part of the Fmoc-RGD building block plays a dual role of a structural component and a biological ligand. Spectroscopic and imaging analysis using CD, FTIR, fluorescence, TEM and AFM confirmed that FF and RGD peptide sequences self-assemble into beta-sheets interlocked by pi-pi stacking of the Fmoc groups. This generates the cylindrical nanofibres interwoven within the hydrogel with the presence of RGDs in tunable densities on the fibre surfaces. This rapid gelling material was observed to promote adhesion of encapsulated dermal fibroblasts through specific RGD-integrin binding, with subsequent cell spreading and proliferation; therefore it may offer an economical model scaffold to 3D-culture other anchorage-dependent cells for in-vitro tissue regeneration. PMID:19201459

  9. Thermosensitive chitosan-Pluronic hydrogel as an injectable cell delivery carrier for cartilage regeneration.

    Science.gov (United States)

    Park, Kyung Min; Lee, Sang Young; Joung, Yoon Ki; Na, Jae Sik; Lee, Myung Chul; Park, Ki Dong

    2009-07-01

    Injectable hydrogels have been studied for potential applications for articular cartilage regeneration. In this study, a thermosensitive chitosan-Pluronic (CP) hydrogel was designed as an injectable cell delivery carrier for cartilage regeneration. The CP conjugate was synthesized by grafting Pluronic onto chitosan using EDC/NHS chemistry. The sol-gel phase transition and mechanical properties of the CP hydrogel were examined by rheological experiments. The CP solution underwent a sol-gel transition around 25 degrees C at which the storage modulus (G') approaches 10(4)Pa, highlighting the potential of this material as an injectable scaffold for cartilage regeneration. The CP hydrogel was formed rapidly by increasing the temperature. The morphology of the dried CP hydrogel was observed by scanning electron microscopy. In vitro cell culture was performed using bovine chondrocytes. The proliferation of bovine chondrocytes and the amount of synthesized glycosaminoglycan increased for 28 days. These results suggested that the CP hydrogel has potential as an injectable cell delivery carrier for cartilage regeneration and could serve as a new biomaterial for tissue engineering. PMID:19261553

  10. Cell-Controlled and Spatially Arrayed Gene Delivery from Fibrin Hydrogels

    OpenAIRE

    Lei, Pedro; Padmashali, Roshan; Andreadis, Stelios T.

    2009-01-01

    We investigated fibrin-mediated gene transfer by embedding pDNA within the hydrogel during polymerization and using two modes of gene transfection with cells placed either on the surface (2D transfection) or within the hydrogel (3D transfection). Using this model, we found that cell transfection depended strongly on the local cell-pDNA microenvironment as defined by the 2D vs. 3D context, target cell type and density, as well as fibrinogen and pDNA concentrations. When cells were embedded wit...

  11. Self-assembling Fmoc dipeptide hydrogel for in situ 3D cell culturing

    Science.gov (United States)

    Liebmann, Thomas; Rydholm, Susanna; Akpe, Victor; Brismar, Hjalmar

    2007-01-01

    Background Conventional cell culture studies have been performed on 2D surfaces, resulting in flat, extended cell growth. More relevant studies are desired to better mimic 3D in vivo tissue growth. Such realistic environments should be the aim of any cell growth study, requiring new methods for culturing cells in vitro. Cell biology is also tending toward miniaturization for increased efficiency and specificity. This paper discusses the application of a self-assembling peptide-derived hydrogel for use as a 3D cell culture scaffold at the microscale. Results Phenylalanine derivative hydrogel formation was seen to occur in multiple dispersion media. Cells were immobilized in situ within microchambers designed for cell analysis. Use of the highly biocompatible hydrogel components and simplistic procedures significantly reduced the cytotoxic effects seen with alternate 3D culture materials and microstructure loading methods. Cells were easily immobilized, sustained and removed from microchambers. Differences in growth morphology were seen in the cultured cells, owing to the 3-dimentional character of the gel structure. Degradation improved the removal of hydrogel from the microstructures, permitting reuse of the analysis platforms. Conclusion Self-assembling diphenylalanine derivative hydrogel provided a method to dramatically reduce the typical difficulties of microculture formation. Effective generation of patterned 3D cultures will lead to improved cell study results by better modeling in vivo growth environments and increasing efficiency and specificity of cell studies. Use of simplified growth scaffolds such as peptide-derived hydrogel should be seen as highly advantageous and will likely become more commonplace in cell culture methodology. PMID:18070345

  12. Self-assembling Fmoc dipeptide hydrogel for in situ 3D cell culturing

    Directory of Open Access Journals (Sweden)

    Akpe Victor

    2007-12-01

    Full Text Available Abstract Background Conventional cell culture studies have been performed on 2D surfaces, resulting in flat, extended cell growth. More relevant studies are desired to better mimic 3D in vivo tissue growth. Such realistic environments should be the aim of any cell growth study, requiring new methods for culturing cells in vitro. Cell biology is also tending toward miniaturization for increased efficiency and specificity. This paper discusses the application of a self-assembling peptide-derived hydrogel for use as a 3D cell culture scaffold at the microscale. Results Phenylalanine derivative hydrogel formation was seen to occur in multiple dispersion media. Cells were immobilized in situ within microchambers designed for cell analysis. Use of the highly biocompatible hydrogel components and simplistic procedures significantly reduced the cytotoxic effects seen with alternate 3D culture materials and microstructure loading methods. Cells were easily immobilized, sustained and removed from microchambers. Differences in growth morphology were seen in the cultured cells, owing to the 3-dimentional character of the gel structure. Degradation improved the removal of hydrogel from the microstructures, permitting reuse of the analysis platforms. Conclusion Self-assembling diphenylalanine derivative hydrogel provided a method to dramatically reduce the typical difficulties of microculture formation. Effective generation of patterned 3D cultures will lead to improved cell study results by better modeling in vivo growth environments and increasing efficiency and specificity of cell studies. Use of simplified growth scaffolds such as peptide-derived hydrogel should be seen as highly advantageous and will likely become more commonplace in cell culture methodology.

  13. Designing Visible Light-Cured Thiol-Acrylate Hydrogels for Studying the HIPPO Pathway Activation in Hepatocellular Carcinoma Cells.

    Science.gov (United States)

    Lin, Tsai-Yu; Bragg, John C; Lin, Chien-Chi

    2016-04-01

    Various polymerization mechanisms have been developed to prepare peptide-immobilized poly(ethylene glycol) (PEG) hydrogels, a class of biomaterials suitable for studying cell biology in vitro. Here, a visible light mediated thiol-acrylate photopolymerization scheme is reported to synthesize dually degradable PEG-peptide hydrogels with controllable crosslinking and degradability. The influence of immobilized monothiol pendant peptide is systematically evaluated on the crosslinking of these hydrogels. Further, methods are proposed to modulate hydrogel crosslinking, including adjusting concentration of comonomer or altering the design of multifunctional peptide crosslinker. Due to the formation of thioether ester bonds, these hydrogels are hydrolytically degradable. If the dithiol peptide linkers used are susceptible to protease cleavage, these thiol-acrylate hydrogels can be designed to undergo partial proteolysis. The differences between linear and multiarm PEG-acrylate (i.e., PEGDA vs PEG4A) are also evaluated. Finally, the use of the mixed-mode thiol-acrylate PEG4A-peptide hydrogels is explored for in situ encapsulation of hepatocellular carcinoma cells (Huh7). The effects of matrix stiffness and integrin binding motif (e.g., RGDS) on Huh7 cell growth and HIPPO pathway activation are studied using PEG4A-peptide hydrogels. This visible light poly-merized thiol-acrylate hydrogel system represents an alternative to existing light-cured hydrogel platforms and shall be useful in many biomedical applications. PMID:26709469

  14. 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

  15. Biomimetic poly(amidoamine hydrogels as synthetic materials for cell culture

    Directory of Open Access Journals (Sweden)

    Lenardi Cristina

    2008-11-01

    Full Text Available Abstract Background Poly(amidoamines (PAAs are synthetic polymers endowed with many biologically interesting properties, being highly biocompatible, non toxic and biodegradable. Hydrogels based on PAAs can be easily modified during the synthesis by the introduction of functional co-monomers. Aim of this work is the development and testing of novel amphoteric nanosized poly(amidoamine hydrogel film incorporating 4-aminobutylguanidine (agmatine moieties to create RGD-mimicking repeating units for promoting cell adhesion. Results A systematic comparative study of the response of an epithelial cell line was performed on hydrogels with agmatine and on non-functionalized amphoteric poly(amidoamine hydrogels and tissue culture plastic substrates. The cell adhesion on the agmatine containing substrates was comparable to that on plastic substrates and significantly enhanced with respect to the non-functionalized controls. Interestingly, spreading and proliferation on the functionalized supports are slower than on plastic exhibiting the possibility of an easier control of the cell growth kinetics. In order to favor the handling of the samples, a procedure for the production of bi-layered constructs was also developed by means the deposition via spin coating of a thin layer of hydrogel on a pre-treated cover slip. Conclusion The obtained results reveal that PAAs hydrogels can be profitably functionalized and, in general, undergo physical and chemical modifications to meet specific requirements. In particular the incorporation of agmatine warrants good potential in the field of cell culturing and the development of supported functionalized hydrogels on cover glass are very promising substrates for applications in cell screening devices.

  16. In vivo evaluation of a neural stem cell-seeded prosthesis

    Science.gov (United States)

    Purcell, E. K.; Seymour, J. P.; Yandamuri, S.; Kipke, D. R.

    2009-04-01

    Neural prosthetics capable of recording or stimulating neuronal activity may restore function for patients with motor and sensory deficits resulting from injury or degenerative disease. However, overcoming inconsistent recording quality and stability in chronic applications remains a significant challenge. A likely reason for this is the reactive tissue response to the devices following implantation into the brain, which is characterized by neuronal loss and glial encapsulation. We have developed a neural stem cell-seeded probe to facilitate integration of a synthetic prosthesis with the surrounding brain tissue. We fabricated parylene devices that include an open well seeded with neural stem cells encapsulated in an alginate hydrogel scaffold. Quantitative and qualitative data describing the distribution of neuronal, glial, and progenitor cells surrounding seeded and control devices are reported over four time points spanning 3 months. Neuronal loss and glial encapsulation associated with cell-seeded probes were mitigated during the initial week of implantation and exacerbated by 6 weeks post-insertion compared to control conditions. We hypothesize that graft cells secrete neuroprotective and neurotrophic factors that effect the desired healing response early in the study, with subsequent cell death and scaffold degradation accounting for a reversal of these results later. Applications of this biohybrid technology include future long-term neural recording and sensing studies.

  17. Preparation of open porous polycaprolactone microspheres and their applications as effective cell carriers in hydrogel system

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Qingchun [Key Laboratory for Ultrafine Materials of Ministry of Education, School of Materials Science and Engineering (China); Tan, Ke; Ye, Zhaoyang [State Key Laboratory of Bioreactor Engineering, School of Bioengineering, East China University of Science and Technology, Shanghai, 200237 China (China); Zhang, Yan, E-mail: zhang_yan@ecust.edu.cn [Key Laboratory for Ultrafine Materials of Ministry of Education, School of Materials Science and Engineering (China); Tan, Wensong [State Key Laboratory of Bioreactor Engineering, School of Bioengineering, East China University of Science and Technology, Shanghai, 200237 China (China); Lang, Meidong, E-mail: mdlang@ecust.edu.cn [Key Laboratory for Ultrafine Materials of Ministry of Education, School of Materials Science and Engineering (China)

    2012-12-01

    Common hydrogel, composed of synthetic polymers or natural polysaccharides could not support the adhesion of anchorage-dependent cells due to the lack of cell affinitive interface and high cell constraint. The use of porous polyester microspheres as cell-carriers and introduction of cell-loaded microspheres into the hydrogel system might overcome the problem. However, the preparation of the open porous microsphere especially using polycaprolactone (PCL) has been rarely reported. Here, the open porous PCL microspheres were fabricated via the combined emulsion/solvent evaporation and particle leaching method. The microspheres exhibited porous surface and inter-connective pore structure. Additionally, the pore structure could be easily controlled by adjusting the processing parameters. The surface pore size could be altered from 20 {mu}m to 80 {mu}m and the internal porosities were varied from 30% to 70%. The obtained microspheres were evaluated to delivery mesenchymal stem cells (MSCs) and showed the improved cell adhesion and growth when compared with the non-porous microspheres. Then, the MSCs loaded microspheres were introduced into agarose hydrogel. MSCs remained alive and sustained proliferation in microsphere/agarose composite in 5-day incubation while a decrement of MSCs viabilities was found in agarose hydrogel without microspheres. The results indicated that the microsphere/hydrogel composite had a great potential in cell therapy and injectable system for tissue regeneration. Highlights: Black-Right-Pointing-Pointer The open porous polycaprolactone microspheres were fabricated using paraffin as a porogen. Black-Right-Pointing-Pointer The microspheres exhibited porous surface and inter-connective pore structure. Black-Right-Pointing-Pointer The surface and internal pore size and porosity of microsphere could be controlled. Black-Right-Pointing-Pointer The porous microspheres exhibited an improved cell adhesion and proliferation. Black

  18. Preparation of open porous polycaprolactone microspheres and their applications as effective cell carriers in hydrogel system

    International Nuclear Information System (INIS)

    Common hydrogel, composed of synthetic polymers or natural polysaccharides could not support the adhesion of anchorage-dependent cells due to the lack of cell affinitive interface and high cell constraint. The use of porous polyester microspheres as cell-carriers and introduction of cell-loaded microspheres into the hydrogel system might overcome the problem. However, the preparation of the open porous microsphere especially using polycaprolactone (PCL) has been rarely reported. Here, the open porous PCL microspheres were fabricated via the combined emulsion/solvent evaporation and particle leaching method. The microspheres exhibited porous surface and inter-connective pore structure. Additionally, the pore structure could be easily controlled by adjusting the processing parameters. The surface pore size could be altered from 20 μm to 80 μm and the internal porosities were varied from 30% to 70%. The obtained microspheres were evaluated to delivery mesenchymal stem cells (MSCs) and showed the improved cell adhesion and growth when compared with the non-porous microspheres. Then, the MSCs loaded microspheres were introduced into agarose hydrogel. MSCs remained alive and sustained proliferation in microsphere/agarose composite in 5-day incubation while a decrement of MSCs viabilities was found in agarose hydrogel without microspheres. The results indicated that the microsphere/hydrogel composite had a great potential in cell therapy and injectable system for tissue regeneration. Highlights: ► The open porous polycaprolactone microspheres were fabricated using paraffin as a porogen. ► The microspheres exhibited porous surface and inter-connective pore structure. ► The surface and internal pore size and porosity of microsphere could be controlled. ► The porous microspheres exhibited an improved cell adhesion and proliferation. ► Mesenchymal stem cells survived and proliferated in microsphere/hydrogel composite.

  19. Fabrication of hydrogels with steep stiffness gradients for studying cell mechanical response.

    Directory of Open Access Journals (Sweden)

    Raimon Sunyer

    Full Text Available Many fundamental cell processes, such as angiogenesis, neurogenesis and cancer metastasis, are thought to be modulated by extracellular matrix stiffness. Thus, the availability of matrix substrates having well-defined stiffness profiles can be of great importance in biophysical studies of cell-substrate interaction. Here, we present a method to fabricate biocompatible hydrogels with a well defined and linear stiffness gradient. This method, involving the photopolymerization of films by progressively uncovering an acrylamide/bis-acrylamide solution initially covered with an opaque mask, can be easily implemented with common lab equipment. It produces linear stiffness gradients of at least 115 kPa/mm, extending from ∼1 kPa to 240 kPa (in units of Young's modulus. Hydrogels with less steep gradients and narrower stiffness ranges can easily be produced. The hydrogels can be covalently functionalized with uniform coatings of proteins that promote cell adhesion. Cell spreading on these hydrogels linearly correlates with hydrogel stiffness, indicating that this technique effectively modifies the mechanical environment of living cells. This technique provides a simple approach that produces steeper gradients, wider rigidity ranges, and more accurate profiles than current methods.

  20. Preparation of graphene oxide/polyacrylamide composite hydrogel and its effect on Schwann cells attachment and proliferation.

    Science.gov (United States)

    Li, Guicai; Zhao, Yinxin; Zhang, Luzhong; Gao, Ming; Kong, Yan; Yang, Yumin

    2016-07-01

    Various hydrogel materials have been developed for improving the regeneration of peripheral nerve. Among which the graphene related hydrogels with excellent mechanical properties have attracted great attention. However, the effect of these hydrogels on peripheral nerve regeneration is still unclear. In the present study, the graphene oxide/polyacrylamide (GO/PAM) composite hydrogels were fabricated by in-situ free radical polymerization. The morphology, wettability, composition, swelling ratio, mechanical property and degradation behavior of the prepared GO/PAM composite hydrogels were separately characterized. The effect of GO/PAM hydrogel on the attachment and proliferation of Schwann cells was evaluated. Moreover, the release of biofactors by Schwann cells and adsorption of matrix proteins were further measured. The results showed that the color of the hydrogel became darker with the increased GO concentration, while the surface pore structure also displayed large variation when GO concentration was increased. The hydrophobicity and mechanical properties of hydrogel were increased with the ascending GO concentration. In addition, the variation of GO concentration displayed no obvious influence on the degradation of the composite hydrogel in different medium. The GO/PAM composite hydrogel with 0.4% GO (G0.4) could effectively enhance the attachment and proliferation of Schwann cells. Furthermore, the cells on G0.4 hydrogel displayed higher biofactors release and larger matrix adsorption than other samples. The results demonstrated that GO with suitable concentration in PAM hydrogel could effectively promote Schwann cell growth. The study may provide an important experimental basis for the design and development of new nerve grafts with potential application for peripheral nerve regeneration. PMID:27058512

  1. Guidance of mesenchymal stem cells on fibronectin structured hydrogel films.

    Directory of Open Access Journals (Sweden)

    Annika Kasten

    Full Text Available Designing of implant surfaces using a suitable ligand for cell adhesion to stimulate specific biological responses of stem cells will boost the application of regenerative implants. For example, materials that facilitate rapid and guided migration of stem cells would promote tissue regeneration. When seeded on fibronectin (FN that was homogeneously immmobilized to NCO-sP(EO-stat-PO, which otherwise prevents protein binding and cell adhesion, human mesenchymal stem cells (MSC revealed a faster migration, increased spreading and a more rapid organization of different cellular components for cell adhesion on fibronectin than on a glass surface. To further explore, how a structural organization of FN controls the behavior of MSC, adhesive lines of FN with varying width between 10 µm and 80 µm and spacings between 5 µm and 20 µm that did not allow cell adhesion were generated. In dependance on both line width and gaps, cells formed adjacent cell contacts, were individually organized in lines, or bridged the lines. With decreasing sizes of FN lines, speed and directionality of cell migration increased, which correlated with organization of the actin cytoskeleton, size and shape of the nuclei as well as of focal adhesions. Together, defined FN lines and gaps enabled a fine tuning of the structural organization of cellular components and migration. Microstructured adhesive substrates can mimic the extracellular matrix in vivo and stimulate cellular mechanisms which play a role in tissue regeneration.

  2. Alginate based hydrogel as a potential biopolymeric carrier for drug delivery and cell delivery systems: present status and applications.

    Science.gov (United States)

    Giri, Tapan Kumar; Thakur, Deepa; Alexander, Amit; Ajazuddin; Badwaik, Hemant; Tripathi, Dulal Krishna

    2012-11-01

    Alginate is a non-toxic, biocompatible and biodegradable natural polymer with a number of peculiar physicochemical properties for which it has wide applications in drug delivery and cell delivery systems. Hydrogel formation can be obtained by interactions of anionic alginates with multivalent inorganic cations by simple ionotropic gelation method. Hydrophilic polymeric network of three dimensional cross linked structures of hydrogels absorb substantial amount of water or biological fluids. Among the numerous biomaterials used for hydrogel formation alginate has been and will continue to be one of the most important biomaterial. Therefore, in view of the vast literature support, we focus in this review on alginate - based hydrogel as drug delivery and cell delivery carriers for biomedical applications. Various properties of alginates, their hydrogels and also various techniques used for preparing alginate hydrogels have been reviewed. PMID:22998675

  3. 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.

  4. 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

  5. A photonic crystal hydrogel suspension array for the capture of blood cells from whole blood

    Science.gov (United States)

    Zhang, Bin; Cai, Yunlang; Shang, Luoran; Wang, Huan; Cheng, Yao; Rong, Fei; Gu, Zhongze; Zhao, Yuanjin

    2016-02-01

    Diagnosing hematological disorders based on the separation and detection of cells in the patient's blood is a significant challenge. We have developed a novel barcode particle-based suspension array that can simultaneously capture and detect multiple types of blood cells. The barcode particles are polyacrylamide (PAAm) hydrogel inverse opal microcarriers with characteristic reflection peak codes that remain stable during cell capture on their surfaces. The hydrophilic PAAm hydrogel scaffolds of the barcode particles can entrap various plasma proteins to capture different cells in the blood, with little damage to captured cells.Diagnosing hematological disorders based on the separation and detection of cells in the patient's blood is a significant challenge. We have developed a novel barcode particle-based suspension array that can simultaneously capture and detect multiple types of blood cells. The barcode particles are polyacrylamide (PAAm) hydrogel inverse opal microcarriers with characteristic reflection peak codes that remain stable during cell capture on their surfaces. The hydrophilic PAAm hydrogel scaffolds of the barcode particles can entrap various plasma proteins to capture different cells in the blood, with little damage to captured cells. Electronic supplementary information (ESI) available. See DOI: 10.1039/c5nr06368j

  6. Dynamic three-dimensional micropatterned cell co-cultures within photocurable and chemically degradable hydrogels.

    Science.gov (United States)

    Sugiura, Shinji; Cha, Jae Min; Yanagawa, Fumiki; Zorlutuna, Pinar; Bae, Hojae; Khademhosseini, Ali

    2016-08-01

    In this paper we report on the development of dynamically controlled three-dimensional (3D) micropatterned cellular co-cultures within photocurable and chemically degradable hydrogels. Specifically, we generated dynamic co-cultures of micropatterned murine embryonic stem (mES) cells with human hepatocellular carcinoma (HepG2) cells within 3D hydrogels. HepG2 cells were used due to their ability to direct the differentiation of mES cells through secreted paracrine factors. To generate dynamic co-cultures, mES cells were first encapsulated within micropatterned photocurable poly(ethylene glycol) (PEG) hydrogels. These micropatterned cell-laden PEG hydrogels were subsequently surrounded by calcium alginate (Ca-Alg) hydrogels containing HepG2 cells. After 4 days, the co-culture step was halted by exposing the system to sodium citrate solution, which removed the alginate gels and the encapsulated HepG2 cells. The encapsulated mES cells were then maintained in the resulting cultures for 16 days and cardiac differentiation was analysed. We observed that the mES cells that were exposed to HepG2 cells in the co-cultures generated cells with higher expression of cardiac genes and proteins, as well as increased spontaneous beating. Due to its ability to control the 3D microenvironment of cells in a spatially and temporally regulated manner, the method presented in this study is useful for a range of cell-culture applications related to tissue engineering and regenerative medicine. Copyright © 2013 John Wiley & Sons, Ltd. PMID:24170301

  7. Direct-write bioprinting of cell-laden methacrylated gelatin hydrogels

    International Nuclear Information System (INIS)

    Fabrication of three dimensional (3D) organoids with controlled microarchitectures has been shown to enhance tissue functionality. Bioprinting can be used to precisely position cells and cell-laden materials to generate controlled tissue architecture. Therefore, it represents an exciting alternative for organ fabrication. Despite the rapid progress in the field, the development of printing processes that can be used to fabricate macroscale tissue constructs from ECM-derived hydrogels has remained a challenge. Here we report a strategy for bioprinting of photolabile cell-laden methacrylated gelatin (GelMA) hydrogels. We bioprinted cell-laden GelMA at concentrations ranging from 7 to 15% with varying cell densities and found a direct correlation between printability and the hydrogel mechanical properties. Furthermore, encapsulated HepG2 cells preserved cell viability for at least eight days following the bioprinting process. In summary, this work presents a strategy for direct-write bioprinting of a cell-laden photolabile ECM-derived hydrogel, which may find widespread application for tissue engineering, organ printing and the development of 3D drug discovery platforms. (paper)

  8. Tubular scaffolds of gelatin and poly(ε-caprolactone)-block-poly(γ-glutamic acid) blending hydrogel for the proliferation of the primary intestinal smooth muscle cells of rats

    International Nuclear Information System (INIS)

    The proper regeneration of intestinal muscle for functional peristalsis is the most challenging aspect of current small intestine tissue engineering. This study aimed to fabricate a hydrogel scaffold for the proliferation of intestinal smooth muscle cells (ISMCs). Tubular porous scaffolds of 10–20 wt% gelatin and 0.05–0.1 wt% poly(ε-caprolactone)-block-poly(γ-glutamic acid) blending hydrogel were cross-linked by carbodiimide and succinimide in an annular space of a glass mold. The scaffolds with higher gelatin contents degraded slower in the phosphate buffer solution. In rheological measurements, the hydrated scaffolds were elastic (all tangent delta <0.45); they responded differentially to frequency, indicating a complete viscoelastic property that is beneficial for soft tissue regeneration. Isolated rat ISMCs, with the characteristic biomarkers α-SMA, calponin and myh11, were loaded into the scaffolds by using either static or centrifugal methods. The average cell density inside the scaffolds increased in a time-dependent manner in most scaffolds of both seeding groups, although at early time points (seven days) the centrifugal seeding method trapped cells more efficiently and yielded a higher cell density than the static seeding method. The static seeding method increased the cell density from 7.5-fold to 16.3-fold after 28 days, whereas the centrifugal procedure produced a maximum increase of only 2.4-fold in the same period. In vitro degradation data showed that 50–80% of the scaffold was degraded by the 14th day. However, the self-secreted extracellular matrix maintained the integrity of the scaffolds for cell proliferation and spreading for up to 28 days. Confocal microscopic images revealed cell–cell contacts with the formation of a 3D network, demonstrating that the fabricated scaffolds were highly biocompatible. Therefore, these polymeric biomaterials hold great promise for in vivo applications of intestinal tissue engineering. (paper)

  9. Fabrication of tubular tissue constructs by centrifugal casting of cells suspended in an in situ crosslinkable hyaluronan-gelatin hydrogel.

    Science.gov (United States)

    Mironov, Vladimir; Kasyanov, Vladimir; Zheng Shu, Xiao; Eisenberg, Carol; Eisenberg, Leonard; Gonda, Steve; Trusk, Thomas; Markwald, Roger R; Prestwich, Glenn D

    2005-12-01

    Achieving the optimal cell density and desired cell distribution in scaffolds is a major goal of cell seeding technologies in tissue engineering. In order to reach this goal, a novel centrifugal casting technology was developed using in situ crosslinkable hyaluronan-based (HA) synthetic extracellular matrix (sECM). Living cells were suspended in a viscous solution of thiol-modified HA and thiol-modified gelatin, a polyethyleneglycol diacrylate crosslinker was added, and a hydrogel was formed during rotation. The tubular tissue constructs consisting of a densely packed cell layer were fabricated with the rotation device operating at 2000 rpm for 10 min. The majority of cells suspended in the HA mixture before rotation were located inside the layer after centrifugal casting. Cells survived the effect of the centrifugal forces experienced under the rotational regime employed. The volume cell density (65.6%) approached the maximal possible volume density based on theoretical sphere packing models. Thus, centrifugal casting allows the fabrication of tubular constructs with the desired redistribution, composition and thickness of cell layers that makes the maximum efficient use of available cells. Centrifugal casting in this sECM would enable rapid fabrication of tissue-engineered vascular grafts, as well as other tubular and planar tissue-engineered constructs. PMID:16023201

  10. Rupture force of cell adhesion ligand tethers modulates biological activities of a cell-laden hydrogel.

    Science.gov (United States)

    Lee, Min Kyung; Park, Jooyeon; Wang, Xuefeng; Roein-Peikar, Mehdi; Ko, Eunkyung; Qin, Ellen; Lee, Jonghwi; Ha, Taekjip; Kong, Hyunjoon

    2016-04-01

    Recent efforts to design a synthetic extracellular matrix for cell culture, engineering, and therapies greatly contributed to addressing biological roles of types and spatial organization of cell adhesion ligands. It is often suggested that ligand-matrix bond strength is another path to regulate cell adhesion and activities; however tools are lacking. To this end, this study demonstrates that a hydrogel coupled with integrin-binding deoxyribonucleic acid (DNA) tethers with pre-defined rupture forces can modulate cell adhesion, differentiation, and secretion activities due to the changes in the number and, likely, force of cells adhered to a gel. The rupture force of DNA tethers was tuned by altering the spatial arrangement of matrix-binding biotin groups. The DNA tethers were immobilized on a hydrogel of alginate grafted with biotin using avidin. Mesenchymal stem cells showed enhanced adhesion, neural differentiation, and paracrine secretion when cultured on the gel coupled with DNA tethers with higher rupture forces. Such innovative cell-matrix interface engineering would be broadly useful for a series of materials used for fundamental and applied studies on biological cells. PMID:26912186

  11. Immobilization of yeast cells on hydrogel carriers obtained by radiation-induced polymerization

    Science.gov (United States)

    Xin, Lu Zhao; Carenza, Mario; Kaetsu, Isao; Kumakura, Minoru; Yoshida, Masaru; Fujimura, Takashi

    Polymer hydrogels were obtained by radiation-induced copolymerization at -78°C of aqueous solutions of acrylic and methacrylic esters. The matrices were characterized by equilibrium water content measurements, by optical microscopy observations and by scanning electron microscopy analysis. Yeast cells were immobilized on these hydrogels and the ethanol productivity by batch fermentation was determined. Matrix hydrophilicity and porosity were found to deeply influence the adhesion of yeast cells and, hence, the ethanol productivity. The latter as well as other physico-chemical properties were also affected by the presence of a crosslinking agent added in small amounts to the polymerizing mixture.

  12. Immobilization of yeast cells on hydrogel carriers obtained by radiation-induced polymerization

    International Nuclear Information System (INIS)

    Polymer hydrogels were obtained by radiation-induced copolymerization at -78oC of aqueous solutions of acrylic and methacrylic esters. The matrices were characterized by equilibrium water content measurements, by optical microscopy observations and by scanning electron microscopy analysis. Yeast cells were immobilized on these hydrogels and the ethanol productivity by batch fermentation was determined. Matrix hydrophilicity and porosity were found to deeply influence the adhesion of yeast cells and, hence, the ethanol productivity. The latter as well as other physico-chemical properties were also affected by the presence of a crosslinking agent added in small amounts to the polymerizating mixture. (author)

  13. Exploring natural silk protein sericin for regenerative medicine: an injectable, photoluminescent, cell-adhesive 3D hydrogel

    Science.gov (United States)

    Wang, Zheng; Zhang, Yeshun; Zhang, Jinxiang; Huang, Lei; Liu, Jia; Li, Yongkui; Zhang, Guozheng; Kundu, Subhas C.; Wang, Lin

    2014-11-01

    Sericin, a major component of silk, has a long history of being discarded as a waste during silk processing. The value of sericin for tissue engineering is underestimated and its potential application in regenerative medicine has just begun to be explored. Here we report the successful fabrication and characterization of a covalently-crosslinked 3D pure sericin hydrogel for delivery of cells and drugs. This hydrogel is injectable, permitting its implantation through minimally invasive approaches. Notably, this hydrogel is found to exhibit photoluminescence, enabling bioimaging and in vivo tracking. Moreover, this hydrogel system possesses excellent cell-adhesive capability, effectively promoting cell attachment, proliferation and long-term survival of various types of cells. Further, the sericin hydrogel releases bioactive reagents in a sustained manner. Additionally, this hydrogel demonstrates good elasticity, high porosity, and pH-dependent degradation dynamics, which are advantageous for this sericin hydrogel to serve as a delivery vehicle for cells and therapeutic drugs. With all these unique features, it is expected that this sericin hydrogel will have wide utility in the areas of tissue engineering and regenerative medicine.

  14. A protein-based hydrogel for in vitro expansion of mesenchymal stem cells.

    Directory of Open Access Journals (Sweden)

    Jingyu Wang

    Full Text Available Hydrogels are widely used as scaffolds in tissue engineering because they can provide excellent environments for bioactive components including growth factors and cells. We reported in this study on a physical hydrogel formed by a specific protein-peptide interaction, which could be used for the three dimensional (3D cell culture of murine mesenchymal stem cells (mMSC. The mMSC kept dividing during the 7-day culture period and the metabolic-active cell number at day 7 was 359% more than that at day 1. This kind of physical hydrogel could be converted to a homogeneous solution by firstly adding an equal volume of culture medium and then pipeting for several times. Therefore, mMSC post culture could be easily separated from cell-gel constructs. We believed that the protein-based hydrogel system in this study could be developed into a promising scaffold for in vitro expansion of stem cells and cell therapy. This work would be in the general interests of researchers in the fields of biomaterials and supramolecular chemistry.

  15. Reversal of Oxidative Stress in Neural Cells by an Injectable Curcumin/Thermosensitive Hydrogel.

    Science.gov (United States)

    Lu, Chuan

    2016-01-01

    Curcumin as an antioxidative agent which has been widely used medicinally in India and China. However, rapid metabolism coupled with the instability of curcumin under physiological conditions has greatly limited its applications in vivo. In the present study, a thermosensitive hydrogel with high payload of curcumin was developed by using a co-precipitation method, and its reversion of oxidative stress in Neuro-2a cells was investigated. With an increase in drug loading capacity, the solgel transition temperature of the thermosensitive hydrogel decreased accordingly. The stability of curcumin in phosphate-buffered saline (PBS; pH=7.4) was greatly improved by encapsulation in the thermosensitive hydrogel, as indicated by an in vitro degradation test. An in vitro release study showed that the encapsulated curcumin was rapidly released from the hydrogel within 6 h. A curcumin/F-127 aqueous solution under the threshold concentration of 4μg/mL was non-toxic against Neuro-2a cells after 24-h incubation. A MitoSOX assay indicated that the developed curcumin formulation could attenuate the oxidative damage induced by H2O2 as compared to that of the H2O2 group. All these results suggested that the developed curcumin/thermosensitive hydrogel might have great potential application in the reversion of oxidative stress after traumatic brain injury. PMID:26549040

  16. Patterned hydrogel microfibers prepared using multilayered microfluidic devices for guiding network formation of neural cells

    International Nuclear Information System (INIS)

    Multilayered microfluidic devices with a micronozzle array structure have been developed to prepare unique hydrogel microfibers with highly complex cross-sectional morphologies. Hydrogel precursor solutions with different compositions are introduced through vertical micronozzles, united and focused, and continuously gelled to form hydrogel fibers with multiple regions of different physicochemical composition. We prepared alginate hydrogel microfibers with diameters of 60 ∼ 130 μm and 4/8 parallel regions in the periphery. Neuron-like PC12 cells encapsulated in the parallel region, which was made of a soft hydrogel matrix, proliferated and formed linear intercellular networks along the fiber length because of the physical restrictions imposed by the relatively rigid regions. After cultivation for 14 days, one-millimeter-long intercellular networks that structurally mimic complex nerve bundles found in vivo were formed. The proposed fibers should be useful for producing various in vivo linear tissues and should be applicable to regenerative medicine and physiological studies of cells. (papers)

  17. 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

  18. A Poroelastic Model Describing Nutrient Transport and Cell Stresses Within a Cyclically Strained Collagen Hydrogel

    Science.gov (United States)

    Vaughan, Benjamin L.; Galie, Peter A.; Stegemann, Jan P.; Grotberg, James B.

    2013-01-01

    In the creation of engineered tissue constructs, the successful transport of nutrients and oxygen to the contained cells is a significant challenge. In highly porous scaffolds subject to cyclic strain, the mechanical deformations can induce substantial fluid pressure gradients, which affect the transport of solutes. In this article, we describe a poroelastic model to predict the solid and fluid mechanics of a highly porous hydrogel subject to cyclic strain. The model was validated by matching the predicted penetration of a bead into the hydrogel from the model with experimental observations and provides insight into nutrient transport. Additionally, the model provides estimates of the wall-shear stresses experienced by the cells embedded within the scaffold. These results provide insight into the mechanics of and convective nutrient transport within a cyclically strained hydrogel, which could lead to the improved design of engineered tissues. PMID:24209865

  19. A method for preparation of hydrogel microcapsules for stem cell bioprocessing and stem cell therapy.

    Science.gov (United States)

    Goldshmid, Revital; Mironi-Harpaz, Iris; Shachaf, Yonatan; Seliktar, Dror

    2015-08-01

    A method for the preparation of suspension culture microcapsules used in the bioprocessing of human mesenchymal stem cells (hMSCs) is reported. The microcapsules are prepared from a semi-synthetic hydrogel comprising Pluronic®F127 conjugated to denatured fibrinogen. The Pluronic-fibrinogen adducts display a lower critical solubility temperature (LCST) at ∼30 °C, thus enabling mild, cell-compatible physical crosslinking of the microcapsules in a warm gelation bath. Cell-laden microgels were prepared from a solution of Pluronic-fibrinogen hydrogel precursor and hMSCs; these were cultivated for up to 15 days in laboratory-scale suspension bioreactors and harvested by reducing the temperature of the microcapsules to disassemble the physical polymer network. The viability, proliferation and cell recovery yields of the hMSCs were shown to be better than photo-chemically crosslinked microcapsules made from a similar material. The cell culture yields, which exceeded 300% after 15 days in suspension culture, were comparable to other microcarrier systems used for the mass production of hMSCs. The simplicity of this methodology, both in terms of the cell inoculation and mild recovery conditions, represent distinct advantages for stem cell bioprocessing with suspension culture bioreactors. PMID:25931428

  20. Hydroxyapatite nanoparticle injectable hydrogel scaffold to support osteogenic differentiation of human mesenchymal stem cells.

    Science.gov (United States)

    Thorpe, A A; Creasey, S; Sammon, C; Le Maitre, C L

    2016-01-01

    Bone loss associated with degenerative disease and trauma is a clinical problem increasing with the aging population. Thus, effective bone augmentation strategies are required; however, many have the disadvantages that they require invasive surgery and often the addition of expensive growth factors to induce osteoblast differentiation. Here, we investigated a LaponiteÒ crosslinked, pNIPAM-DMAc copolymer (L-pNIPAM-co-DMAc) hydrogel with hydroxyapatite nanoparticles (HAPna), which can be maintained as a liquid ex vivo, injected via narrow-gauge needle into affected bone, followed by in situ gelation to deliver and induce osteogenic differentiation of human mesenchymal stem cells (hMSC). L-pNIPAM-co-DMAc hydrogels were synthesised and HAPna added post polymerisation. Commercial hMSCs from one donor (Lonza) were incorporated in liquid hydrogel, the mixture solidified and cultured for up to 6 weeks. Viability of hMSCs was maintained within hydrogel constructs containing 0.5 mg/mL HAPna. SEM analysis demonstrated matrix deposition in cellular hydrogels which were absent in acellular controls. A significant increase in storage modulus (G') was observed in cellular hydrogels with 0.5 mg/mL HAPna. Semi-quantitative immunohistochemistry and histological analysis demonstrated that bone differentiation markers and collagen deposition was induced within 48 h, with increased calcium deposition with time. The thermally triggered hydrogel system, described here, was sufficient without the need of additional growth factors or osteogenic media to induce osteogenic differentiation of commercial hMSCs. Preliminary data presented here will be expanded on multiple patient samples to ensure differentiation is seen in these samples. This system could potentially reduce treatment costs and simplify the treatment strategy for orthopaedic repair and regeneration. PMID:27377664

  1. Differentiation and Behavior of Dental Pulp Stem Cells in Hydrogel Scaffolds of Various Stiffnesses

    Science.gov (United States)

    Bhatnagar, Divya; Jurukovski, Vladimir; Rafailovich, Miriam; Simon, Marcia

    2011-03-01

    Dental Pulp Stem Cells (DPSCs) are known to differentiate in bone, dentine, or nerve tissue through different environment signals. This work investigates whether differentiation could occur in the absence of chemical induction and through mechanical stimuli only. For this study, we chose enzymatically cross-linked gelatin hydrogels as our substrates. Rheological studies carried out by oscillatory shear rheometry indicated that the modulus of the hardest hydrogel was of the order of 8kPa where as the medium and the softest hydrogel had modulus of the order of 1kPa and 100Pa respectively. DPSC were then plated on all three substrates and cultured with and without dexamethasone induction media. After 21 days of incubation, SEM analysis indicated that the cells cultured in the induction media produced biomineralized deposits on hard, medium as well as soft hydrogels. On the other hand, the cells cultured without the induction media also produced large amounts of biomineralized deposits.The modulus of the cells was also measured using AFM. En mass cell migration was also studied to determine the average velocity of migration of DPSCs. We also investigated whether stem cells that are induced to differentiate by their scaffold environment would continue to differentiate and biomineralize when removed from the inducing scaffold.

  2. Rheological and biological properties of a hydrogel support for cells intended for intervertebral disc repair

    Directory of Open Access Journals (Sweden)

    Benz Karin

    2012-04-01

    Full Text Available Abstract Background Cell-based approaches towards restoration of prolapsed or degenerated intervertebral discs are hampered by a lack of measures for safe administration and placement of cell suspensions within a treated disc. In order to overcome these risks, a serum albumin-based hydrogel has been developed that polymerizes after injection and anchors the administered cell suspension within the tissue. Methods A hydrogel composed of chemically activated albumin crosslinked by polyethylene glycol spacers was produced. The visco-elastic gel properties were determined by rheological measurement. Human intervertebral disc cells were cultured in vitro and in vivo in the hydrogel and their phenotype was tested by reverse-transcriptase polymerase chain reaction. Matrix production and deposition was monitored by immuno-histology and by biochemical analysis of collagen and glycosaminoglycan deposition. Species specific in situ hybridization was performed to discriminate between cells of human and murine origin in xenotransplants. Results The reproducibility of the gel formation process could be demonstrated. The visco-elastic properties were not influenced by storage of gel components. In vitro and in vivo (subcutaneous implants in mice evidence is presented for cellular differentiation and matrix deposition within the hydrogel for human intervertebral disc cells even for donor cells that have been expanded in primary monolayer culture, stored in liquid nitrogen and re-activated in secondary monolayer culture. Upon injection into the animals, gels formed spheres that lasted for the duration of the experiments (14 days. The expression of cartilage- and disc-specific mRNAs was maintained in hydrogels in vitro and in vivo, demonstrating the maintenance of a stable specific cellular phenotype, compared to monolayer cells. Significantly higher levels of hyaluronan synthase isozymes-2 and -3 mRNA suggest cell functionalities towards those needed for the

  3. Sliced Magnetic Polyacrylamide Hydrogel with Cell-Adhesive Microarray Interface: A Novel Multicellular Spheroid Culturing Platform.

    Science.gov (United States)

    Hu, Ke; Zhou, Naizhen; Li, Yang; Ma, Siyu; Guo, Zhaobin; Cao, Meng; Zhang, Qiying; Sun, Jianfei; Zhang, Tianzhu; Gu, Ning

    2016-06-22

    Cell-adhesive properties are of great significance to materials serving as extracellular matrix mimics. Appropriate cell-adhesive property of material interface can balance the cell-matrix interaction and cell-cell interaction and can promote cells to form 3D structures. Herein, a novel magnetic polyacrylamide (PAM) hydrogel fabricated via combining magnetostatic field induced magnetic nanoparticles assembly and hydrogel gelation was applied as a multicellular spheroids culturing platform. When cultured on the cell-adhesive microarray interface of sliced magnetic hydrogel, normal and tumor cells from different cell lines could rapidly form multicellular spheroids spontaneously. Furthermore, cells which could only form loose cell aggregates in a classic 3D cell culture model (such as hanging drop system) were able to be promoted to form multicellular spheroids on this platform. In the light of its simplicity in fabricating as well as its effectiveness in promoting formation of multicellular spheroids which was considered as a prevailing tool in the study of the microenvironmental regulation of tumor cell physiology and therapeutic problems, this composite material holds promise in anticancer drugs or hyperthermia therapy evaluation in vitro in the future. PMID:27258682

  4. Formulation Changes Affect Material Properties and Cell Behavior in HA-Based Hydrogels

    Directory of Open Access Journals (Sweden)

    Thomas Lawyer

    2012-01-01

    Full Text Available To develop and optimize new scaffold materials for tissue engineering applications, it is important to understand how changes to the scaffold affect the cells that will interact with that scaffold. In this study, we used a hyaluronic acid- (HA- based hydrogel as a synthetic extracellular matrix, containing modified HA (CMHA-S, modified gelatin (Gtn-S, and a crosslinker (PEGda. By varying the concentrations of these components, we were able to change the gelation time, enzymatic degradation, and compressive modulus of the hydrogel. These changes also affected fibroblast spreading within the hydrogels and differentially affected the proliferation and metabolic activity of fibroblasts and mesenchymal stem cells (MSCs. In particular, PEGda concentration had the greatest influence on gelation time, compressive modulus, and cell spreading. MSCs appeared to require a longer period of adjustment to the new microenvironment of the hydrogels than fibroblasts. Fibroblasts were able to proliferate in all formulations over the course of two weeks, but MSCs did not. Metabolic activity changed for each cell type during the two weeks depending on the formulation. These results highlight the importance of determining the effect of matrix composition changes on a particular cell type of interest in order to optimize the formulation for a given application.

  5. Development of 3-D Hydrogel Culture Systems With On-Demand Cell Separation

    OpenAIRE

    Hamilton, Sharon K.; Bloodworth, Nathaniel C.; Massad, Christopher S.; Hammoudi, Taymour M.; Suri, Shalu; Yang, Peter J.; Lu, Hang; Temenoff, Johnna S.

    2013-01-01

    Recently there has been an increased interest in the effects of paracrine signaling between groups of cells, particularly in the context of better understanding how stem cells contribute to tissue repair. Most current 3-D co-culture methods lack the ability to effectively separate 2 cell populations after the culture period, which is important for simultaneously analyzing the reciprocal effects of each cell type on the other. Here, we detail the development of a 3-D hydrogel co-culture system...

  6. Laminin Peptide-Immobilized Hydrogels Modulate Valve Endothelial Cell Hemostatic Regulation.

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    Liezl Rae Balaoing

    Full Text Available Valve endothelial cells (VEC have unique phenotypic responses relative to other types of vascular endothelial cells and have highly sensitive hemostatic functions affected by changes in valve tissues. Furthermore, effects of environmental factors on VEC hemostatic function has not been characterized. This work used a poly(ethylene glycol diacrylate (PEGDA hydrogel platform to evaluate the effects of substrate stiffness and cell adhesive ligands on VEC phenotype and expression of hemostatic genes. Hydrogels of molecular weights (MWs 3.4, 8, and 20 kDa were polymerized into platforms of different rigidities and thiol-modified cell adhesive peptides were covalently bound to acrylate groups on the hydrogel surfaces. The peptide RKRLQVQLSIRT (RKR is a syndecan-1 binding ligand derived from laminin, a trimeric protein and a basement membrane matrix component. Conversely, RGDS is an integrin binding peptide found in many extracellular matrix (ECM proteins including fibronectin, fibrinogen, and von Willebrand factor (VWF. VECs adhered to and formed a stable monolayer on all RKR-coated hydrogel-MW combinations. RGDS-coated platforms supported VEC adhesion and growth on RGDS-3.4 kDa and RGDS-8 kDa hydrogels. VECs cultured on the softer RKR-8 kDa and RKR-20 kDa hydrogel platforms had significantly higher gene expression for all anti-thrombotic (ADAMTS-13, tissue factor pathway inhibitor, and tissue plasminogen activator and thrombotic (VWF, tissue factor, and P-selectin proteins than VECs cultured on RGDS-coated hydrogels and tissue culture polystyrene controls. Stimulated VECs promoted greater platelet adhesion than non-stimulated VECs on their respective culture condition; yet stimulated VECs on RGDS-3.4 kDa gels were not as responsive to stimulation relative to the RKR-gel groups. Thus, the syndecan binding, laminin-derived peptide promoted stable VEC adhesion on the softer hydrogels and maintained VEC phenotype and natural hemostatic function. In

  7. Laminin Peptide-Immobilized Hydrogels Modulate Valve Endothelial Cell Hemostatic Regulation.

    Science.gov (United States)

    Balaoing, Liezl Rae; Post, Allison Davis; Lin, Adam Yuh; Tseng, Hubert; Moake, Joel L; Grande-Allen, K Jane

    2015-01-01

    Valve endothelial cells (VEC) have unique phenotypic responses relative to other types of vascular endothelial cells and have highly sensitive hemostatic functions affected by changes in valve tissues. Furthermore, effects of environmental factors on VEC hemostatic function has not been characterized. This work used a poly(ethylene glycol) diacrylate (PEGDA) hydrogel platform to evaluate the effects of substrate stiffness and cell adhesive ligands on VEC phenotype and expression of hemostatic genes. Hydrogels of molecular weights (MWs) 3.4, 8, and 20 kDa were polymerized into platforms of different rigidities and thiol-modified cell adhesive peptides were covalently bound to acrylate groups on the hydrogel surfaces. The peptide RKRLQVQLSIRT (RKR) is a syndecan-1 binding ligand derived from laminin, a trimeric protein and a basement membrane matrix component. Conversely, RGDS is an integrin binding peptide found in many extracellular matrix (ECM) proteins including fibronectin, fibrinogen, and von Willebrand factor (VWF). VECs adhered to and formed a stable monolayer on all RKR-coated hydrogel-MW combinations. RGDS-coated platforms supported VEC adhesion and growth on RGDS-3.4 kDa and RGDS-8 kDa hydrogels. VECs cultured on the softer RKR-8 kDa and RKR-20 kDa hydrogel platforms had significantly higher gene expression for all anti-thrombotic (ADAMTS-13, tissue factor pathway inhibitor, and tissue plasminogen activator) and thrombotic (VWF, tissue factor, and P-selectin) proteins than VECs cultured on RGDS-coated hydrogels and tissue culture polystyrene controls. Stimulated VECs promoted greater platelet adhesion than non-stimulated VECs on their respective culture condition; yet stimulated VECs on RGDS-3.4 kDa gels were not as responsive to stimulation relative to the RKR-gel groups. Thus, the syndecan binding, laminin-derived peptide promoted stable VEC adhesion on the softer hydrogels and maintained VEC phenotype and natural hemostatic function. In conclusion

  8. An Optimized Injectable Hydrogel Scaffold Supports Human Dental Pulp Stem Cell Viability and Spreading

    Directory of Open Access Journals (Sweden)

    T. D. Jones

    2016-01-01

    Full Text Available Introduction. HyStem-C™ is a commercially available injectable hydrogel composed of polyethylene glycol diacrylate (PEGDA, hyaluronan (HA, and gelatin (Gn. These components can be mechanically tuned to enhance cell viability and spreading. Methods. The concentration of PEGDA with an added disulfide bond (PEGSSDA was varied from 0.5 to 8.0% (w/v to determine the optimal concentration for injectable clinical application. We evaluated the cell viability of human dental pulp stem cells (hDPSCs embedded in 2% (w/v PEGSSDA-HA-Gn hydrogels. Volume ratios of HA : Gn from 100 : 0 to 25 : 75 were varied to encourage hDPSC spreading. Fibronectin (Fn was added to our model to determine the effect of extracellular matrix protein concentration on hDPSC behavior. Results. Our preliminary data suggests that the hydrogel gelation time decreased as the PEGSSDA cross-linker concentration increased. The PEGSSDA-HA-Gn was biocompatible with hDPSCs, and increased ratios of HA : Gn enhanced cell viability for 14 days. Additionally, cell proliferation with added fibronectin increased significantly over time at concentrations of 1.0 and 10.0 μg/mL in PEGDA-HA-Gn hydrogels, while cell spreading significantly increased at Fn concentrations of 0.1 μg/mL. Conclusions. This study demonstrates that PEG-based injectable hydrogels maintain hDPSC viability and facilitate cell spreading, mainly in the presence of extracellular matrix (ECM proteins.

  9. An Optimized Injectable Hydrogel Scaffold Supports Human Dental Pulp Stem Cell Viability and Spreading

    Science.gov (United States)

    Jones, T. D.; Kefi, A.; Sun, S.; Cho, M.; Alapati, S. B.

    2016-01-01

    Introduction. HyStem-C™ is a commercially available injectable hydrogel composed of polyethylene glycol diacrylate (PEGDA), hyaluronan (HA), and gelatin (Gn). These components can be mechanically tuned to enhance cell viability and spreading. Methods. The concentration of PEGDA with an added disulfide bond (PEGSSDA) was varied from 0.5 to 8.0% (w/v) to determine the optimal concentration for injectable clinical application. We evaluated the cell viability of human dental pulp stem cells (hDPSCs) embedded in 2% (w/v) PEGSSDA-HA-Gn hydrogels. Volume ratios of HA : Gn from 100 : 0 to 25 : 75 were varied to encourage hDPSC spreading. Fibronectin (Fn) was added to our model to determine the effect of extracellular matrix protein concentration on hDPSC behavior. Results. Our preliminary data suggests that the hydrogel gelation time decreased as the PEGSSDA cross-linker concentration increased. The PEGSSDA-HA-Gn was biocompatible with hDPSCs, and increased ratios of HA : Gn enhanced cell viability for 14 days. Additionally, cell proliferation with added fibronectin increased significantly over time at concentrations of 1.0 and 10.0 μg/mL in PEGDA-HA-Gn hydrogels, while cell spreading significantly increased at Fn concentrations of 0.1 μg/mL. Conclusions. This study demonstrates that PEG-based injectable hydrogels maintain hDPSC viability and facilitate cell spreading, mainly in the presence of extracellular matrix (ECM) proteins. PMID:27294191

  10. Stem cell secretome-rich nanoclay hydrogel: a dual action therapy for cardiovascular regeneration†

    Science.gov (United States)

    Waters, Renae; Pacelli, Settimio; Maloney, Ryan; Medhi, Indrani; Ahmed, Rafeeq P. H.

    2016-01-01

    A nanocomposite hydrogel with photocrosslinkable micro-porous networks and a nanoclay component was successfully prepared to control the release of growth factor-rich stem cell secretome. The proven pro-angiogenic and cardioprotective potential of this new bioactive system provides a valuable therapeutic platform for cardiac tissue repair and regeneration. PMID:26876936

  11. Design and performance of a sericin-alginate interpenetrating network hydrogel for cell and drug delivery

    Science.gov (United States)

    Zhang, Yeshun; Liu, Jia; Huang, Lei; Wang, Zheng; Wang, Lin

    2015-07-01

    Although alginate hydrogels have been extensively studied for tissue engineering applications, their utilization is limited by poor mechanical strength, rapid drug release, and a lack of cell adhesive ability. Aiming to improve these properties, we employ the interpenetrating hydrogel design rationale. Using alginate and sericin (a natural protein with many unique properties and a major component of silkworm silk), we develop an interpenetrating polymer network (IPN) hydrogel comprising interwoven sericin and alginate double networks. By adjusting the sericin-to-alginate ratios, IPNs’ mechanical strength can be adjusted to meet stiffness requirements for various tissue repairs. The IPNs with high sericin content show increased stability during degradation, avoiding pure alginate’s early collapse. These IPNs have high swelling ratios, benefiting various applications such as drug delivery. The IPNs sustain controlled drug release with the adjustable rates. Furthermore, these IPNs are adhesive to cells, supporting cell proliferation, long-term survival and migration. Notably, the IPNs inherit sericin’s photoluminescent property, enabling bioimaging in vivo. Together, our study indicates that the sericin-alginate IPN hydrogels may serve as a versatile platform for delivering cells and drugs, and suggests that sericin may be a building block broadly applicable for generating IPN networks with other biomaterials for diverse tissue engineering applications.

  12. A photopolymerizable hydrogel for 3-D culture of human embryonic stem cell-derived cardiomyocytes and rat neonatal cardiac cells.

    Science.gov (United States)

    Shapira-Schweitzer, Keren; Habib, Manhal; Gepstein, Lior; Seliktar, Dror

    2009-02-01

    The purpose of this study was to assess the in vitro ability of two types of cardiomyocytes (cardiomyocytes derived from human embryonic stem cells (hESC-CM) and rat neonatal cardiomyocytes (rN-CM)) to survive and generate a functional cardiac syncytium in a three-dimensional in situ polymerizable hydrogel environment. Each cell type was cultured in a PEGylated fibrinogen (PF) hydrogel for up to two weeks while maturation and cardiac function were documented in terms of spontaneous contractile behavior and biomolecular organization. Quantitative contractile parameters including contraction amplitude and synchronization were measured by non-invasive image analysis. The rN-CM demonstrated the fastest maturation and the most significant spontaneous contraction. The hESC-CM maturation occurred between 10-14 days in culture, and exhibited less contraction amplitude and synchronization in comparison to the rN-CMs. The maturation of both cell types within the hydrogels was confirmed by cardiac-specific biomolecular markers, including alpha-sarcomeric actin, actinin, and connexin-43. Cellular responsiveness to isoproterenol, carbamylcholine and heptanol provided further evidence of the cardiac maturation in the 3-D PF hydrogel as well as identified a potential to use this system for in vitro drug screening. These findings indicate that the PF hydrogel biomaterial can be used as an in situ polymerizable biomaterial for stem cells and their cardiomyocyte derivatives. PMID:19027751

  13. Impedimetric quantification of cells encapsulated in hydrogel cultured in a paper-based microchamber.

    Science.gov (United States)

    Lei, Kin Fong; Huang, Chia-Hao; Tsang, Ngan-Ming

    2016-01-15

    Recently, 3D cell culture technique was proposed to provide a more physiologically-meaningful environment for cell-based assays. With the development of microfluidics technology, cellular response can be quantified by impedance measurement technique in a real-time and non-invasive manner. However, handling of these microfluidic systems requires a trained engineering personnel and the operation is not compatible to traditional biological research laboratories. In this work, we incorporated the impedance measurement technique to paper-based 3D cell culture model and demonstrated non-invasive quantification of cells encapsulated in hydrogel during the culture course. A cellulose filter paper was patterned with an array of circular microchambers. Cells were encapsulated in hydrogel and loaded to the microchambers for culturing cells in 3D environment. At the preset schedule during the culture course, the paper was placed on a glass substrate with measurement electrodes for the impedance measurement. Cells in each microchamber was represented by impedance magnitude and cell proliferation could be studied over time. Also, conventional bio-assay was performed to further confirm the feasibility of the impedimetric quantification of cells encapsulated in hydrogel cultured in the paper-based microchamber. This technique provides a convenient, fast, and non-invasive approach to monitor cells cultured in 3D environment. It has potential to be developed for routine 3D cell culture protocol in biological research laboratories. PMID:26592655

  14. Design of Decorated Self-Assembling Peptide Hydrogels as Architecture for Mesenchymal Stem Cells

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    Annj Zamuner

    2016-08-01

    Full Text Available Hydrogels from self-assembling ionic complementary peptides have been receiving a lot of interest from the scientific community as mimetic of the extracellular matrix that can offer three-dimensional supports for cell growth or can become vehicles for the delivery of stem cells, drugs or bioactive proteins. In order to develop a 3D “architecture” for mesenchymal stem cells, we propose the introduction in the hydrogel of conjugates obtained by chemoselective ligation between a ionic-complementary self-assembling peptide (called EAK and three different bioactive molecules: an adhesive sequence with 4 Glycine-Arginine-Glycine-Aspartic Acid-Serine-Proline (GRGDSP motifs per chain, an adhesive peptide mapped on h-Vitronectin and the growth factor Insulin-like Growth Factor-1 (IGF-1. The mesenchymal stem cell adhesion assays showed a significant increase in adhesion and proliferation for the hydrogels decorated with each of the synthesized conjugates; moreover, such functionalized 3D hydrogels support cell spreading and elongation, validating the use of this class of self-assembly peptides-based material as very promising 3D model scaffolds for cell cultures, at variance of the less realistic 2D ones. Furthermore, small amplitude oscillatory shear tests showed that the presence of IGF-1-conjugate did not alter significantly the viscoelastic properties of the hydrogels even though differences were observed in the nanoscale structure of the scaffolds obtained by changing their composition, ranging from long, well-defined fibers for conjugates with adhesion sequences to the compact and dense film for the IGF-1-conjugate.

  15. Single-cell hydrogel encapsulation for enhanced survival of human marrow stromal cells.

    Science.gov (United States)

    Karoubi, Golnaz; Ormiston, Mark L; Stewart, Duncan J; Courtman, David W

    2009-10-01

    Inadequate extracellular matrix cues and subsequent apoptotic cell death are among crucial factors currently limiting cell viability and organ retention in cell-based therapeutic strategies for vascular regeneration. Here we describe the use of a single-cell hydrogel capsule to provide enhanced cell survival of adherent cells in transient suspension culture. Human marrow stromal cells (hMSCs) were singularly encapsulated in agarose capsules containing the immobilized matrix molecules, fibronectin and fibrinogen to ameliorate cell-matrix survival signals. MSCs in the enriched capsules demonstrated increased viability, greater metabolic activity and enhanced cell-cytoskeletal patterning. Increased cell viability resulted from the re-induction of cell-matrix interactions likely via integrin clustering and subsequent activation of the extracellular signal regulated MAPK (ERK)/mitogen activated protein kinase (MAPK) signaling cascade. Proof of principle in-vivo studies, investigating autologous MSC delivery into Fisher 344 rat hindlimb, depicted a significant increase in the number of engrafted cells using the single-cell encapsulation system. Incorporation of immobilized adhesion molecules compensates, at least in part, for the missing cell-matrix cues, thereby attenuating the initial anoikis stimuli and providing protection from subsequent apoptosis. Thus, this single-cell encapsulation strategy may markedly enhance therapeutic cell survival in targeted tissues. PMID:19595454

  16. Design of Cell-Matrix Interactions in Hyaluronic Acid Hydrogel Scaffolds

    OpenAIRE

    Lam, Jonathan; Truong, Norman F.; Segura, Tatiana

    2013-01-01

    The design of hyaluronic acid-based hydrogel scaffolds to elicit highly controlled and tunable cell response and behavior is a major field of interest in developing tissue engineering and regenerative medicine applications. This review will begin with an overview of the biological context of hyaluronic acid, knowledge needed to better understand how to engineer cell-matrix interactions in the scaffolds via the incorporation of different types of signals in order to direct and control cell beh...

  17. Cellulose Nanofibril Hydrogel Tubes as Sacrificial Templates for Freestanding Tubular Cell Constructs.

    Science.gov (United States)

    Torres-Rendon, Jose Guillermo; Köpf, Marius; Gehlen, David; Blaeser, Andreas; Fischer, Horst; De Laporte, Laura; Walther, Andreas

    2016-03-14

    The merging of defined nanoscale building blocks with advanced additive manufacturing techniques is of eminent importance for the preparation of multiscale and highly functional materials with de novo designed hierarchical architectures. Here, we demonstrate that hydrogels of cellulose nanofibrils (CNF) can be processed into complex shapes, and used as a sacrificial template to prepare freestanding cell constructs. We showcase our approach for the fabrication of hollow fibers using a controlled extrusion through a circular die into a coagulation bath. The dimensions of the hollow fibers are tunable, and the final tubes combine the nanofibrillar porosity of the CNF hydrogel with a submillimeter wall thickness and centimeter-scale length provided by the additive manufacturing technique. We demonstrate that covalent and supramolecular cross-linking of the CNFs can be used to tailor the mechanical properties of the hydrogel tubes within 1 order of magnitude and in an attractive range for the mechanosensation of cells. The resulting tubes are highly biocompatible and allow for the growth of mouse fibroblasts into confluent cell layers in their inner lumen. A detailed screening of several cellulases enables degradation of the scaffolding, temporary CNF hydrogel tube in a quick and highly cell-friendly way, and allows the isolation of coherent cell tubes. We foresee that the growing capabilities of hydrogel printing techniques in combination with the attractive features of CNFs-sustainable, globally abundant, biocompatible and enzymatically degradable-will allow making plant-based biomaterials with hierarchical structures and on-demand degradation useful, for instance, to engineer complex tissue structures to replace animal models, and for implants. PMID:26812393

  18. Synthesis of Thermal Polymerizable Alginate-GMA Hydrogel for Cell Encapsulation

    Directory of Open Access Journals (Sweden)

    Xiaokun Wang

    2015-01-01

    Full Text Available Alginate is a negative ionic polysaccharide that is found abundantly in nature. Calcium is usually used as a cross-linker for alginate. However, calcium cross-linked alginate is used only for in vitro culture. In the present work, alginate was modified with glycidyl methacrylate (GMA to produce a thermal polymerizable alginate-GMA (AA-GMA macromonomer. The molecular structure and methacrylation (%DM of the macromonomer were determined by 1H NMR. After mixing with the correct amount of initiator, the AA-GMA aqueous solution can be polymerized at physiological temperature. The AA-GMA hydrogels exhibited a three-dimensional porous structure with an average pore size ranging from 50 to 200 μm, directly depending on the macromonomer concentration. Biocompatibility of the AA-GMA hydrogel was determined by in vivo muscle injection and cell encapsulation. Muscle injection in vivo showed that the AA-GMA solution mixed with initiator could form a hydrogel in situ and had a mild inflammatory effect. Human umbilical vein endothelial cells (HUVECs were encapsulated in the AA-GMA hydrogels in situ at 37°C. Cell viability and proliferation were unaffected by macromonomer concentrations, which suggests that AA-GMA has a potential application in the field of tissue engineering, especially for myocardial repair.

  19. Sequential ionic and thermogelation of chitosan spherical hydrogels prepared using superhydrophobic surfaces to immobilize cells and drugs

    OpenAIRE

    A. C. Lima; Correia, Clara R.; Oliveira, Mariana B.; Mano, J.F.

    2014-01-01

    Chitosan is soluble in acidic media, which makes it incompatible for the encapsulation of cells and pH-sensitive molecules. In this work, a mild chitosan-based system with two sequential gelation steps is proposed, where the model drug dexamethasone and L929 cells are immobilized inside hydrogel beads. Superhydrophobic surfaces were used to produce the spherical hydrogel particles that provided favorable conditions to encapsulate cells or bioactive agents. First, the chitosan a...

  20. Cell-controlled and spatially arrayed gene delivery from fibrin hydrogels.

    Science.gov (United States)

    Lei, Pedro; Padmashali, Roshan M; Andreadis, Stelios T

    2009-08-01

    We investigated fibrin-mediated gene transfer by embedding pDNA within the hydrogel during polymerization and using two modes of gene transfection with cells placed either on the surface (2D transfection) or within the hydrogel (3D transfection). Using this model, we found that cell transfection depended strongly on the local cell-pDNA microenvironment as defined by the 2D vs. 3D context, target cell type and density, as well as fibrinogen and pDNA concentrations. When cells were embedded within the fibrin matrix lipofectamine-induced cell death decreased significantly, especially at low target cell density. Addition of fibrinolytic inhibitors decreased gene transfer in a dose-dependent manner, suggesting that fibrin degradation may be necessary for efficient gene transfer. We also provided proof-of-concept that fibrin-mediated gene transfer can be used for spatially localized gene delivery, which is required in cell-transfection microarrays. When lipoplex-containing hydrogels were spotted in an array format gene transfer was strictly confined to pDNA-containing fibrin spots with no cross-contamination between neighboring sites. Collectively, our data suggest that fibrin may be used as a biomaterial to deliver genes in an efficient, cell-controlled and spatially localized manner for potential applications in vitro or in vivo. PMID:19395019

  1. Temporally degradable collagen-mimetic hydrogels tuned to chondrogenesis of human mesenchymal stem cells.

    Science.gov (United States)

    Parmar, Paresh A; Skaalure, Stacey C; Chow, Lesley W; St-Pierre, Jean-Philippe; Stoichevska, Violet; Peng, Yong Y; Werkmeister, Jerome A; Ramshaw, John A M; Stevens, Molly M

    2016-08-01

    Tissue engineering strategies for repairing and regenerating articular cartilage face critical challenges to recapitulate the dynamic and complex biochemical microenvironment of native tissues. One approach to mimic the biochemical complexity of articular cartilage is through the use of recombinant bacterial collagens as they provide a well-defined biological 'blank template' that can be modified to incorporate bioactive and biodegradable peptide sequences within a precisely defined three-dimensional system. We customized the backbone of a Streptococcal collagen-like 2 (Scl2) protein with heparin-binding, integrin-binding, and hyaluronic acid-binding peptide sequences previously shown to modulate chondrogenesis and then cross-linked the recombinant Scl2 protein with a combination of matrix metalloproteinase 7 (MMP7)- and aggrecanase (ADAMTS4)-cleavable peptides at varying ratios to form biodegradable hydrogels with degradation characteristics matching the temporal expression pattern of these enzymes in human mesenchymal stem cells (hMSCs) during chondrogenesis. hMSCs encapsulated within the hydrogels cross-linked with both degradable peptides exhibited enhanced chondrogenic characteristics as demonstrated by gene expression and extracellular matrix deposition compared to the hydrogels cross-linked with a single peptide. Additionally, these combined peptide hydrogels displayed increased MMP7 and ADAMTS4 activities and yet increased compression moduli after 6 weeks, suggesting a positive correlation between the degradation of the hydrogels and the accumulation of matrix by hMSCs undergoing chondrogenesis. Our results suggest that including dual degradation motifs designed to respond to enzymatic activity of hMSCs going through chondrogenic differentiation led to improvements in chondrogenesis. Our hydrogel system demonstrates a bimodal enzymatically degradable biological platform that can mimic native cellular processes in a temporal manner. As such, this novel

  2. Influence of soluble PEG-OH incorporation in a 3D cell-laden PEG-fibrinogen (PF) hydrogel on smooth muscle cell morphology and growth.

    Science.gov (United States)

    Lee, Bae Hoon; Tin, Stella Poh Hui; Chaw, Su Yin; Cao, Ye; Xia, Yun; Steele, Terry W J; Seliktar, Dror; Bianco-Peled, Havazelet; Venkatraman, Subbu S

    2014-01-01

    We have been able to control hydrogel compliance and cell spreading in a three-dimensional (3D) cell-laden system (hydrogel) using soluble PEG-OH. This was accomplished by encapsulating smooth muscle cells (SMCs) into poly(ethylene glycol)-fibrinogen (PEG-fibrinogen or PF) with poly(ethylene glycol)-diol (PEG-OH) as a macromolecular leachant. The cell-encapsulating hydrogels were prepared with three concentrations of soluble PEG-OH having a mass of 10 kDa (1, 5 and 10% w/v). Rheology was used to measure the elastic (storage) component of the complex shear modulus of these hydrogels, while quantitative morphometrics were used to characterize SMC morphology. PF hydrogel with a higher amount of PEG-OH displayed a lower storage modulus and a higher elongated cell morphology of SMCs. Structural changes of PF hydrogels mainly owing to gelation-induced phase separation imparted by the soluble PEG-OH in 3D cell-laden hydrogels dramatically affected both the properties of the hydrogel network including the modulus as well as cell spreading. PMID:24304216

  3. On chip single-cell separation and immobilization using optical tweezers and thermosensitive hydrogel.

    Science.gov (United States)

    Arai, Fumihito; Ng, Chinaik; Maruyama, Hisataka; Ichikawa, Akihiko; El-Shimy, Haitham; Fukuda, Toshio

    2005-12-01

    A novel approach appropriate for rapid separation and immobilization of a single cell by concomitantly utilizing laser manipulation and locally thermosensitive hydrogelation is proposed in this paper. We employed a single laser beam as optical tweezers for separating a target cell and locating it adjacent to a fabricated, transparent micro heater. Simultaneously, the target cell is immobilized or partially entrapped by heating the thermosensitive hydrogel with the micro heater. The state of the thermosensitive hydrogel can be switched from sol to gel and gel to sol by controlling the temperature through heating and cooling by the micro heater. After other unwanted cells are removed by the high-speed cleaning flow in the microchannel, the entrapped cell is successfully isolated. It is possible to collect the immobilized target cell for analysis or culture by switching off the micro heater and releasing the cell from the entrapment. We demonstrated that the proposed approach is feasible for rapid manipulation, immobilization, cleaning, isolation and extraction of a single cell. The experimental results are shown here. PMID:16286972

  4. Transplantation of adipocyte-derived stem cells in a hydrogel scaffold for the repair of cortical contusion injury in rats.

    Science.gov (United States)

    Xue, Sha; Wu, Gang; Zhang, Hong-tian; Guo, Yan-wu; Zou, Yu-xi; Zhou, Zhen-jun; Jiang, Xiao-dan; Ke, Yi-quan; Xu, Ru-xiang

    2015-04-01

    Adipocyte-derived stem cells have emerged as a novel source of stem cell therapy for their autologous and readily accessible and pluripotent potential to differentiate into different lineages such as neural stem cells (NSCs) and endothelial progenitor cells (EPCs). Transplantation of NSCs and EPCs has been promising for the repair of brain injury. We explored using co-transplanted hydrogel scaffold to improve the survival of the transplanted cells and recovery of neurological function. Adult Wistar rats were transplanted with EPC-hydrogel, NSC-hydrogel, NSC-EPC-hydrogel, EPC only, or NSC only 7 days after cortical contusion injury. Behavioral tests were performed to evaluate neurological function before, and 1, 2, 3, and 4 weeks after transplantation. Size of injury, extent of vascularization, as well as the survival and differentiation of the transplanted EPCs and NSCs, were evaluated at week 5. All transplantation groups displayed significantly better neurological function compared with the control groups. Improved neurological function correlated with significantly smaller injury volumes than that of the saline group. Using immunostaining, we have shown that while transplanted NSCs differentiated into both neurons and astrocytes, the EPCs were incorporated into vessel epithelia. The extent of reactive gliosis (based on glial fibrillary acidic protein immunostaining) was significantly reduced in all treatment groups (NSC-EPC-hydrogel, NSC-hydrogel, and EPC-hydrogel) when compared with the saline group, with the highest reduction in the NSC-EPC-hydrogel transplantation group. Thus, co-transplantation of hydrogel scaffold provides a more conducive environment for the survival and differentiation of NSCs and EPCs at the site of brain injury, leading to improved vascularization and better recovery of neurological function. PMID:25225747

  5. ECM hydrogel for the treatment of stroke: Characterization of the host cell infiltrate.

    Science.gov (United States)

    Ghuman, Harmanvir; Massensini, Andre R; Donnelly, Julia; Kim, Sung-Min; Medberry, Christopher J; Badylak, Stephen F; Modo, Michel

    2016-06-01

    Brain tissue loss following stroke is irreversible with current treatment modalities. The use of an acellular extracellular matrix (ECM), formulated to produce a hydrogel in situ within the cavity formed by a stroke, was investigated as a method to replace necrotic debris and promote the infiltration of host brain cells. Based on magnetic resonance imaging measurements of lesion location and volume, different concentrations of ECM (0, 1, 2, 3, 4, 8 mg/mL) were injected at a volume equal to that of the cavity (14 days post-stroke). Retention of ECM within the cavity occurred at concentrations >3 mg/mL. A significant cell infiltration into the ECM material in the lesion cavity occurred with an average of ∼36,000 cells in the 8 mg/mL concentration within 24 h. An infiltration of cells with distances of >1500 μm into the ECM hydrogel was observed, but the majority of cells were at the tissue/hydrogel boundary. Cells were typically of a microglia, macrophage, or neural and oligodendrocyte progenitor phenotype. At the 8 mg/mL concentration, ∼60% of infiltrating cells were brain-derived phenotypes and 30% being infiltrating peripheral macrophages, polarizing toward an M2-like anti-inflammatory phenotype. These results suggest that an 8 mg/mL ECM concentration promotes a significant acute endogenous repair response that could potentially be exploited to treat stroke. PMID:27031811

  6. Stem Cell Hydrogel, Jump-Starting Zika Drug Discovery, and Engineering RNA Recognition.

    Science.gov (United States)

    Kostic, Milka

    2016-08-18

    Every month the editors of Cell Chemical Biology bring you highlights of the most recent chemical biology literature that impressed them with creativity and potential for follow up work. Our August 2016 selection includes a description of hydrogels with self-tunable stiffness that are used to profile lipid metabolites during stems cell differentiation, a look at whether we can find a drug repurposing solution to Zika virus infection, and an engineered RNA recognition motif (RRM). PMID:27541191

  7. Osteoblastic differentiation of stem cells from human exfoliated deciduous teeth induced by thermosensitive hydrogels with strontium phosphate

    International Nuclear Information System (INIS)

    Stem cells from human exfoliated deciduous teeth (SHEDs) are a novel source of multi-potential stem cells for tissue engineering because of their potential to differentiate into multiple cell lineages. Strontium exhibits an important function in bone remodeling because it can simulate bone formation and decrease bone resorption. Hydrogels can mimic the natural cellular environment. The association of hydrogels with cell viability is determined using biological tests, including rheological experiments. In this study, osteogenic differentiation was investigated through SHED encapsulation in hydrogels containing strontium phosphate. Results of 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) and proliferating cell nuclear antigen (PCNA) immunofluorescence staining indicated that the cells grew well and SHEDs proliferated in the hydrogels. Strontium-loaded chitosan-based hydrogels induced the biomineralization and high expression of alkaline phosphatase. Moreover, the expression levels of bone-related genes, including type-I collagen, Runx2, osteopontin (OP), and osteonectin (ON), were up-regulated during the osteogenic differentiation of SHEDs. This study demonstrated that strontium can be an effective inducer of osteogenesis for SHEDs. Elucidating the function of bioceramics (such as strontium) is useful in designing and developing strategies for bone tissue engineering. - Highlights: • SHEDs have been considered as alternative sources of adult stem cells in tissue engineering. • Strontium phosphate can enhance the osteogenic differentiation of SHEDs. • Hydrogels can mimic the natural cellular environment. • Bioceramics (such as strontium) is useful in designing and developing strategies for bone tissue engineering

  8. Osteoblastic differentiation of stem cells from human exfoliated deciduous teeth induced by thermosensitive hydrogels with strontium phosphate

    Energy Technology Data Exchange (ETDEWEB)

    Su, Wen-Ta, E-mail: f10549@ntut.edu.tw [Department of Chemical Engineering and Biotechnology National Taipei University of Technology, Taipei, Taiwan (China); Chou, Wei-Ling [Department of Chemical Engineering and Biotechnology National Taipei University of Technology, Taipei, Taiwan (China); Chou, Chih-Ming [Department of Biochemistry, Taipei Medical University, Taipei, Taiwan (China)

    2015-07-01

    Stem cells from human exfoliated deciduous teeth (SHEDs) are a novel source of multi-potential stem cells for tissue engineering because of their potential to differentiate into multiple cell lineages. Strontium exhibits an important function in bone remodeling because it can simulate bone formation and decrease bone resorption. Hydrogels can mimic the natural cellular environment. The association of hydrogels with cell viability is determined using biological tests, including rheological experiments. In this study, osteogenic differentiation was investigated through SHED encapsulation in hydrogels containing strontium phosphate. Results of 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) and proliferating cell nuclear antigen (PCNA) immunofluorescence staining indicated that the cells grew well and SHEDs proliferated in the hydrogels. Strontium-loaded chitosan-based hydrogels induced the biomineralization and high expression of alkaline phosphatase. Moreover, the expression levels of bone-related genes, including type-I collagen, Runx2, osteopontin (OP), and osteonectin (ON), were up-regulated during the osteogenic differentiation of SHEDs. This study demonstrated that strontium can be an effective inducer of osteogenesis for SHEDs. Elucidating the function of bioceramics (such as strontium) is useful in designing and developing strategies for bone tissue engineering. - Highlights: • SHEDs have been considered as alternative sources of adult stem cells in tissue engineering. • Strontium phosphate can enhance the osteogenic differentiation of SHEDs. • Hydrogels can mimic the natural cellular environment. • Bioceramics (such as strontium) is useful in designing and developing strategies for bone tissue engineering.

  9. An injectable hydrogel incorporating mesenchymal precursor cells and pentosan polysulphate for intervertebral disc regeneration.

    Science.gov (United States)

    Frith, Jessica E; Cameron, Andrew R; Menzies, Donna J; Ghosh, Peter; Whitehead, Darryl L; Gronthos, Stan; Zannettino, Andrew C W; Cooper-White, Justin J

    2013-12-01

    Intervertebral disc (IVD) degeneration is one of the leading causes of lower back pain and a major health problem worldwide. Current surgical treatments include excision or immobilisation, with neither approach resulting in the repair of the degenerative disc. As such, a tissue engineering-based approach in which stem cells, coupled with an advanced delivery system, could overcome this deficiency and lead to a therapy that encourages functional fibrocartilage generation in the IVD. In this study, we have developed an injectable hydrogel system based on enzymatically-crosslinked polyethylene glycol and hyaluronic acid. We examined the effects of adding pentosan polysulphate (PPS), a synthetic glycosaminoglycan-like factor that has previously been shown (in vitro and in vivo) to this gel system in order to induce chondrogenesis in mesenchymal precursor cells (MPCs) when added as a soluble factor, even in the absence of additional growth factors such as TGF-β. We show that both the gelation rate and mechanical strength of the resulting hydrogels can be tuned in order to optimise the conditions required to produce gels with the desired combination of properties for an IVD scaffold. Human immunoselected STRO-1+ MPCs were then incorporated into the hydrogels. They were shown to retain good viability after both the initial formation of the gel and for longer-term culture periods in vitro. Furthermore, MPC/hydrogel composites formed cartilage-like tissue which was significantly enhanced by the incorporation of PPS into the hydrogels, particularly with respect to the deposition of type-II-collagen. Finally, using a wild-type rat subcutaneous implantation model, we examined the extent of any immune reaction and confirmed that this matrix is well tolerated by the host. Together these data provide evidence that such a system has significant potential as both a delivery vehicle for MPCs and as a matrix for fibrocartilage tissue engineering applications. PMID:24050877

  10. Bio-inspired microstructures in collagen type I hydrogel.

    Science.gov (United States)

    Hosseini, Yahya; Verbridge, Scott S; Agah, Masoud

    2015-06-01

    This article presents a novel technique to fabricate complex type I collagen hydrogel structures, with varying depth and width defined by a single fabrication step. This technique takes advantage of reactive ion etching lag to fabricate three-dimensional (3-D) structures in silicon. Then, a polydimethylsiloxane replica was fabricated utilizing soft lithography and used as a stamp on collagen hydrogel to transfer these patterns. Endothelial cells were seeded on the hydrogel devices to measure their interaction with these more physiologically relevant cell culture surfaces. Confocal imaging was utilized to image the hydrogel devices to demonstrate the robustness of the fabrication technique, and to study the cell-extracellular matrix interaction after cell seeding. In this study, we observed that endothelial cells remodeled the sharp scallops of collagen hydrogel structures and compressed the structures with low degree of slope. Such patterning techniques will enhance the physiological relevance of existing 3-D cell culture platforms by providing a technical bridge between the high resolution yet planar techniques of standard lithography with more complex yet low resolution 3-D printing methods. PMID:25346472

  11. Guiding intracortical brain tumour cells to an extracortical cytotoxic hydrogel using aligned polymeric nanofibres

    Science.gov (United States)

    Jain, Anjana; Betancur, Martha; Patel, Gaurangkumar D.; Valmikinathan, Chandra M.; Mukhatyar, Vivek J.; Vakharia, Ajit; Pai, S. Balakrishna; Brahma, Barunashish; MacDonald, Tobey J.; Bellamkonda, Ravi V.

    2014-03-01

    Glioblastoma multiforme is an aggressive, invasive brain tumour with a poor survival rate. Available treatments are ineffective and some tumours remain inoperable because of their size or location. The tumours are known to invade and migrate along white matter tracts and blood vessels. Here, we exploit this characteristic of glioblastoma multiforme by engineering aligned polycaprolactone (PCL)-based nanofibres for tumour cells to invade and, hence, guide cells away from the primary tumour site to an extracortical location. This extracortial sink is a cyclopamine drug-conjugated, collagen-based hydrogel. When aligned PCL-nanofibre films in a PCL/polyurethane carrier conduit were inserted in the vicinity of an intracortical human U87MG glioblastoma xenograft, a significant number of human glioblastoma cells migrated along the aligned nanofibre films and underwent apoptosis in the extracortical hydrogel. Tumour volume in the brain was significantly lower following insertion of aligned nanofibre implants compared with the application of smooth fibres or no implants.

  12. 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.

  13. Survival of cord blood haematopoietic stem cells in a hyaluronan hydrogel for ex vivo biomimicry.

    Science.gov (United States)

    Demange, Elise; Kassim, Yusra; Petit, Cyrille; Buquet, Catherine; Dulong, Virginie; Cerf, Didier Le; Buchonnet, Gérard; Vannier, Jean-Pierre

    2013-11-01

    Haematopoietic stem cells (HSCs) and haematopoietic progenitor cells (HPCs) grow in a specified niche in close association with the microenvironment, the so-called 'haematopoietic niche'. Scaffolds have been introduced to overcome the liquid culture limitations, mimicking the presence of the extracellular matrix (ECM). In the present study the hyaluronic acid scaffold, already developed in the laboratory, has been used for the first time to maintain long-term cultures of CD34⁺ haematopoietic cells obtained from human cord blood. One parameter investigated was the impact on ex vivo survival of CD34⁺ cord blood cells (CBCs) on the hyaluronic acid surface, immobilized with peptides containing the RGD motif. This peptide was conjugated by coating the hyaluronan hydrogel and cultured in serum-free liquid phase complemented with stem cell factor (SCF), a commonly indispensable cytokine for haematopoiesis. Our work demonstrated that these hyaluronan hydrogels were superior to traditional liquid cultures by maintaining and expanding the HPCs without the need for additional cytokines, and a colonization of 280-fold increment in the hydrogel compared with liquid culture after 28 days of ex vivo expansion. PMID:22473677

  14. PlGF-MMP9-engineered iPS cells supported on a PEG-fibrinogen hydrogel scaffold possess an enhanced capacity to repair damaged myocardium.

    Science.gov (United States)

    Bearzi, C; Gargioli, C; Baci, D; Fortunato, O; Shapira-Schweitzer, K; Kossover, O; Latronico, M V G; Seliktar, D; Condorelli, G; Rizzi, R

    2014-01-01

    Cell-based regenerative therapies are significantly improved by engineering allografts to express factors that increase vascularization and engraftment, such as placental growth factor (PlGF) and matrix metalloproteinase 9 (MMP9). Moreover, the seeding of therapeutic cells onto a suitable scaffold is of utmost importance for tissue regeneration. On these premises, we sought to assess the reparative potential of induced pluripotent stem (iPS) cells bioengineered to secrete PlGF or MMP9 and delivered to infarcted myocardium upon a poly(ethylene glycol)-fibrinogen scaffold. When assessing optimal stiffness of the PEG-fibrinogen (PF) scaffold, we found that the appearance of contracting cells after cardiogenic induction was accelerated on the support designed with an intermediate stiffness. Revascularization and hemodynamic parameters of infarcted mouse heart were significantly improved by injection into the infarct of this optimized PF scaffold seeded with both MiPS (iPS cells engineered to secrete MMP9) and PiPS (iPS cells engineered to secrete PlGF) cells as compared with nonengineered cells or PF alone. Importantly, allograft-derived cells and host myocardium were functionally integrated. Therefore, survival and integration of allografts in the ischemic heart can be significantly improved with the use of therapeutic cells bioengineered to secrete MMP9 and PlGF and encapsulated within an injectable PF hydrogel having an optimized stiffness. PMID:24525729

  15. Stem cell secretome-rich nanoclay hydrogel: a dual action therapy for cardiovascular regeneration

    Science.gov (United States)

    Waters, Renae; Pacelli, Settimio; Maloney, Ryan; Medhi, Indrani; Ahmed, Rafeeq P. H.; Paul, Arghya

    2016-03-01

    A nanocomposite hydrogel with photocrosslinkable micro-porous networks and a nanoclay component was successfully prepared to control the release of growth factor-rich stem cell secretome. The proven pro-angiogenic and cardioprotective potential of this new bioactive system provides a valuable therapeutic platform for cardiac tissue repair and regeneration.A nanocomposite hydrogel with photocrosslinkable micro-porous networks and a nanoclay component was successfully prepared to control the release of growth factor-rich stem cell secretome. The proven pro-angiogenic and cardioprotective potential of this new bioactive system provides a valuable therapeutic platform for cardiac tissue repair and regeneration. Electronic supplementary information (ESI) available. See DOI: 10.1039/c5nr07806g

  16. Visible light cured thiol-vinyl hydrogels with tunable degradation for 3D cell culture

    OpenAIRE

    Hao, Yiting; Shih, Han; Muňoz, Zachary; Kemp, Arika; Lin, Chien-Chi

    2013-01-01

    We report here a synthetically simple yet highly tunable and diverse visible light mediated thiol-vinyl gelation system for fabricating cell-instructive hydrogels. Gelation was achieved via a mixed-mode step-and-chain-growth photopolymerization using functionalized 4-arm poly(ethylene glycol) as backbone macromer, eosin-Y as photosensitizer, and di-thiol containing molecule as dual purpose co-initiator/cross-linker. N-vinylpyrrolidone (NVP) was used to accelerate gelation kinetics and to adju...

  17. Encoding Cell-Instructive Cues to PEG-Based Hydrogels via Triple Helical Peptide Assembly

    OpenAIRE

    Stahl, Patrick J.; Yu, S. Michael

    2012-01-01

    Effective synthetic tissue engineering scaffolds mimic the structure and composition of natural extracellular matrix (ECM) to promote optimal cellular adhesion, proliferation, and differentiation. Among many proteins of the ECM, collagen and fibronectin are known to play a key role in the scaffold’s structural integrity as well as its ability to support cell adhesion. Here, we present photocrosslinked poly(ethylene glycol) diacrylate (PEGDA) hydrogels displaying collagen mimetic peptides (CMP...

  18. Effect of bioglass on growth and biomineralization of SaOS-2 cells in hydrogel after 3D cell bioprinting.

    Directory of Open Access Journals (Sweden)

    Xiaohong Wang

    Full Text Available We investigated the effect of bioglass (bioactive glass on growth and mineralization of bone-related SaOS-2 cells, encapsulated into a printable and biodegradable alginate/gelatine hydrogel. The hydrogel was supplemented either with polyphosphate (polyP, administered as polyP • Ca2+-complex, or silica, or as biosilica that had been enzymatically prepared from ortho-silicate by silicatein. These hydrogels, together with SaOS-2 cells, were bioprinted to computer-designed scaffolds. The results revealed that bioglass (nanoparticles, with a size of 55 nm and a molar ratio of SiO2 : CaO : P2O5 of 55 : 40 : 5, did not affect the growth of the encapsulated cells. If silica, biosilica, or polyP • Ca2+-complex is co-added to the cell-containing alginate/gelatin hydrogel the growth behavior of the cells is not changed. Addition of 5 mg/ml of bioglass particles to this hydrogel significantly enhanced the potency of the entrapped SaOS-2 cells to mineralize. If compared with the extent of the cells to form mineral deposits in the absence of bioglass, the cells exposed to bioglass together with 100 µmoles/L polyP • Ca2+-complex increased their mineralization activity from 2.1- to 3.9-fold, or with 50 µmoles/L silica from 1.8- to 2.9-fold, or with 50 µmoles/L biosilica from 2.7- to 4.8-fold or with the two components together (100 µmoles/L polyP • Ca2+-complex and 50 µmoles/L biosilica from 4.1- to 6.8-fold. Element analysis by EDX spectrometry of the mineral nodules formed by SaOS-2 revealed an accumulation of O, P, Ca and C, indicating that the mineral deposits contain, besides Ca-phosphate also Ca-carbonate. The results show that bioglass added to alginate/gelatin hydrogel increases the proliferation and mineralization of bioprinted SaOS-2 cells. We conclude that the development of cell-containing scaffolds consisting of a bioprintable, solid and cell-compatible inner matrix surrounded by a printable hard and flexible outer matrix containing

  19. Cellular differentiation in 3D-bioprinted mesenchymal stem cell-loaded hydrogels with varying structural and mechanical properties

    OpenAIRE

    Duarte Campos, Daniela Filipa

    2016-01-01

    Hydrogels are a promising alternative to rigid biomaterials typically used in the field of bone tissue engineering for the treatment of musculoskeletal disorders. By hydrogel-based 3D-bioprinting, the native ornamentation of cells and matrix from bone tissue could be resembled. Herein, it was hypothesized the combination of polysaccharides (agarose, alginate) with biological components (collagen, fibrinogen) would increase mechanical stiffness of printed constructs as well as support the prin...

  20. Exploring natural silk protein sericin for regenerative medicine: an injectable, photoluminescent, cell-adhesive 3D hydrogel

    OpenAIRE

    Wang, Zheng; Zhang, Yeshun; Zhang, Jinxiang; Huang, Lei; Liu, Jia; Li, Yongkui; Zhang, Guozheng; Kundu, Subhas C.; Wang, Lin

    2014-01-01

    Sericin, a major component of silk, has a long history of being discarded as a waste during silk processing. The value of sericin for tissue engineering is underestimated and its potential application in regenerative medicine has just begun to be explored. Here we report the successful fabrication and characterization of a covalently-crosslinked 3D pure sericin hydrogel for delivery of cells and drugs. This hydrogel is injectable, permitting its implantation through minimally invasive approac...

  1. Fine Adjustment of Interfacial Potential between pH-Responsive Hydrogels and Cell-Sized Particles.

    Science.gov (United States)

    Monzel, Cornelia; Veschgini, Mariam; Madsen, Jeppe; Lewis, Andrew L; Armes, Steven P; Tanaka, Motomu

    2015-08-11

    We quantitatively determined interfacial potentials between cell-sized particles and stimulus-responsive hydrogels using a microinterferometer. The hydrogel is based on physically interconnected ABA triblock copolymer micelles comprising an inner biocompatible PMPC block and two outer pH-responsive PDPA blocks. The out-of-plane temporal fluctuation in the position of the cell-sized particles was calculated from changes in the interference pattern measured by Reflection Interference Contrast Microscopy (RICM), thus yielding the particle-substrate interaction potential V (Δh). Measurements in pH buffers ranging from 7.0 to 7.8 resulted in a systematic reduction in height of the potential minima ⟨Δh⟩ and a concomitant increase in the potential curvature V″ (Δh). The experimental data were analyzed by applying the modified Ross and Pincus model for polyelectrolytes, while accounting for gravitation, lubrication and van der Waals interactions. Elastic moduli calculated from V″ (Δh) were in good agreement with those measured by Atomic Force Microscopy. The ability to fine-tune both the gel elasticity and the interfacial potential at around physiological pH makes such triblock copolymer hydrogels a promising biocompatible substrate for dynamic switching of cell-material interactions. PMID:26190346

  2. Rapid prototyping of a hybrid hierarchical polyurethane-cell/hydrogel construct for regenerative medicine.

    Science.gov (United States)

    Huang, Yuanwen; He, Kai; Wang, Xiaohong

    2013-08-01

    The creation of branched vascular systems has attracted significant attention from both scientific and clinical areas. However, it is still a formidable challenge to build a three-dimensional (3-D) branched vascular system mimicking the native vascular systems with the traditional or existing fabrication methods. Here we demonstrate rapid manufacturing of a hybrid hierarchical polyurethane-cell/Hydrogel construct by a double-nozzle low-temperature deposition system. Based on this approach, a 3-D vascular template with both synthetic scaffold polymer and cell/hydrogel systems was constructed. The synthetic PU was used as an external scaffold material to provide mechanical support, while the gelatin/alginate/fibrinogen hydrogel was used as an internal scaffold material for adipose-derived stem cell (ADSC) accommodation. After the fabrication stages, the coherent 3-D composite construct was thawed at room temperature, crosslinked/polymerized with aqueous solutions, cultured in vitro under static or dynamic conditions, and embedded in vivo with stable architectures and excellent biocompatibilities. This technology will enable rapid manufacture of complex branched vascular templates for a wide array of scientific and clinical applications. PMID:23706204

  3. Corneal epithelial cell biocompatibility to silicone hydrogel and conventional hydrogel contact lens packaging solutions

    OpenAIRE

    Gorbet, M.B.; Tanti, N.C.; Jones, L.; Sheardown, H.

    2010-01-01

    Purpose Although all contact lenses (CLs) are applied initially to the eye directly from a packaging solution, little is known about the effects of these solutions on human corneal epithelial cells (HCECs). Due to the porous nature of CL materials, they have the potential to sorb components of the packaging solution during storage, which could then be subsequently released upon insertion of the CL on the eye. The purpose of this study was to investigate the effect of various packaging solutio...

  4. Time-dependent cellular morphogenesis and matrix stiffening in proteolytically responsive hydrogels.

    Science.gov (United States)

    Kesselman, Dafna; Kossover, Olga; Mironi-Harpaz, Iris; Seliktar, Dror

    2013-08-01

    Mesenchymal stromal cells residing in proteolytically responsive hydrogel scaffolds were subjected to changes in mechanical properties associated with their own three-dimensional (3-D) morphogenesis. In order to investigate this relationship the current study documents the transient degradation and restructuring of fibroblasts seeded in hydrogel scaffolds undergoing active cell-mediated reorganization over 7days in culture. A semi-synthetic proteolytically degradable polyethylene glycol-fibrinogen (PF) hydrogel matrix and neonatal human dermal fibroblasts (NHDF) were used. Rheology (in situ and ex situ) measured stiffening of the gels and confocal laser scanning microscopy (CLSM) measured cell morphogenesis within the gels. The assumption that the matrix modulus systematically decreases as cells locally begin to enzymatically disassemble the PF hydrogel to become spindled in the material was not supported by the bulk mechanical property measurements. Instead, the PF hydrogels exhibited cell-mediated stiffening concurrent with their dynamic morphogenesis, as indicated by a four-fold increase in storage modulus after 1week in culture. Fibrin hydrogels, which were used as the control biomaterial, proved similarly adaptive to cell-mediated remodeling only in the presence of the exogenous serine protease inhibitor aprotinin. Acellular and non-viable hydrogels also served as control groups to verify that transient matrix remodeling was entirely associated with cell-mediated events, including collagen deposition, cell-mediated proteolysis, and the formation of multicellular networks within the hydrogel constructs. The fact that cell network formation and collagen deposition both paralleled transient stiffening of the PF hydrogels, further reinforces the notion that cells actively balance between proteolysis and ECM synthesis when remodeling proteolytically responsive hydrogel scaffolds. PMID:23624218

  5. Ectopic bone formation in bone marrow stem cell seeded calcium phosphate scaffolds as compared to autograft and (cell seeded allograft

    Directory of Open Access Journals (Sweden)

    J O Eniwumide

    2007-08-01

    Full Text Available Improvements to current therapeutic strategies are needed for the treatment of skeletal defects. Bone tissue engineering offers potential advantages to these strategies. In this study, ectopic bone formation in a range of scaffolds was assessed. Vital autograft and devitalised allograft served as controls and the experimental groups comprised autologous bone marrow derived stem cell seeded allograft, biphasic calcium phosphate (BCP and tricalcium phosphate (TCP, respectively. All implants were implanted in the back muscle of adult Dutch milk goats for 12 weeks. Micro-computed tomography (µCT analysis and histomorphometry was performed to evaluate and quantify ectopic bone formation. In good agreement, both µCT and histomorphometric analysis demonstrated a significant increase in bone formation by cell-seeded calcium phosphate scaffolds as compared to the autograft, allograft and cell-seeded allograft implants. An extensive resorption of the autograft, allograft and cell-seeded allograft implants was observed by histology and confirmed by histomorphometry. Cell-seeded TCP implants also showed distinct signs of degradation with histomorphometry and µCT, while the degradation of the cell-seeded BCP implants was negligible. These results indicate that cell-seeded calcium phosphate scaffolds are superior to autograft, allograft or cell-seeded allograft in terms of bone formation at ectopic implantation sites. In addition, the usefulness of µCT for the efficient and non-destructive analysis of mineralised bone and calcium phosphate scaffold was demonstrated.

  6. Cell differentiation on disk- and string-shaped hydrogels fabricated from Ca(2+) -responsive self-assembling peptides.

    Science.gov (United States)

    Fukunaga, Kazuto; Tsutsumi, Hiroshi; Mihara, Hisakazu

    2016-11-01

    We recently developed a self-assembling peptide, E1Y9, that self-assembles into nanofibers and forms a hydrogel in the presence of Ca(2+) . E1Y9 derivatives conjugated with functional peptide sequences derived from extracellular matrices (ECMs) reportedly self-assemble into peptide nanofibers that enhance cell adhesion and differentiation. In this study, E1Y9/E1Y9-IKVAV-mixed hydrogels were constructed to serve as artificial ECMs that promote cell differentiation. E1Y9 and E1Y9-IKVAV co-assembled into networked nanofibers, and hydrogels with disk and string shapes were formed in response to Ca(2+) treatment. The neuronal differentiation of PC12 cells was facilitated on hydrogels of both shapes that contained the IKVAV motifs. Moreover, long neurites extended along the long axis of the string-shaped gel, suggesting that the structure of hydrogels of this shape can affect cellular orientation. Thus, E1Y9 hydrogels can potentially be used as artificial ECMs with desirable bioactivities and shapes that could be useful in tissue engineering applications. © 2015 Wiley Periodicals, Inc. Biopolymers (Pept Sci) 106: 476-483, 2016. PMID:26501895

  7. Cell-cell interaction between vocal fold fibroblasts and bone marrow mesenchymal stromal cells in three-dimensional hyaluronan hydrogel.

    Science.gov (United States)

    Chen, Xia; Thibeault, Susan L

    2016-05-01

    Mesenchymal stromal cells (MSCs) are multipotential adult cells present in all tissues. Paracrine effects and differentiating ability make MSCs an ideal cell source for tissue regeneration. However, little is known about how interactions between implanted MSCs and native cells influence cellular growth, proliferation, and behaviour. By using an in vitro three-dimensional (3D) co-culture assay of normal or scarred human vocal fold fibroblasts (VFFs) and bone marrow-derived MSCs (BM-MSCs) in a uniquely suited hyaluronan hydrogel (HyStem-VF), we investigated cell morphology, survival rate, proliferation and protein and gene expression of VFFs and BM-MSCs. BM-MSCs inhibited cell proliferation of both normal and scarred VFFs without changes in VFF morphology or viability. BM-MSCs demonstrated decreased proliferation and survival rate after 7 days of co-culture with VFFs. Interactions between BM-MSCs and VFFs led to a significant increase in protein secretion of collagen I and hepatocyte growth factor (HGF) and a decrease of vascular endothelial growth factor (VEGF), monocyte chemotactic protein-1 (MCP-1) and interleukin-6 (IL-6). In particular, BM-MSCs significantly upregulated matrix metalloproteinase 1 (MMP1) and HGF gene expression for scarred VFFs compared to normal VFFs, indicating the potential for increases in extracellular matrix remodelling and tissue regeneration. Application of BM-MSCs-hydrogels may play a significant role in tissue regeneration, providing a therapeutic approach for vocal fold scarring. Copyright © 2013 John Wiley & Sons, Ltd. PMID:23653427

  8. Engineering a Dual-Layer Chitosan-Lactide Hydrogel To Create Endothelial Cell Aggregate-Induced Microvascular Networks In Vitro and Increase Blood Perfusion In Vivo.

    Science.gov (United States)

    Kim, Sungwoo; Kawai, Toshiyuki; Wang, Derek; Yang, Yunzhi

    2016-08-01

    Here, we report the use of chemically cross-linked and photo-cross-linked hydrogels to engineer human umbilical vein endothelial cell (HUVEC) aggregate-induced microvascular networks to increase blood perfusion in vivo. First, we studied the effect of chemically cross-linked and photo-cross-linked chitosan-lactide hydrogels on stiffness, degradation rates, and HUVEC behaviors. The photo-cross-linked hydrogel was relatively stiff (E = ∼15 kPa) and possessed more compact networks, denser surface texture, and lower enzymatic degradation rates than the relatively soft, chemically cross-linked hydrogel (E = ∼2 kPa). While both hydrogels exhibited nontoxicity, the soft chemically cross-linked hydrogels expedited the formation of cell aggregates compared to the photo-cross-linked hydrogels. Cells on the less stiff, chemically cross-linked hydrogels expressed more matrix metalloproteinase (MMP) activity than the stiffer, photo-cross-linked hydrogel. This difference in MMP activity resulted in a more dramatic decrease in mechanical stiffness after 3 days of incubation for the chemically cross-linked hydrogel, as compared to the photo-cross-linked one. After determining the physical and biological properties of each hydrogel, we accordingly engineered a dual-layer hydrogel construct consisting of the relatively soft, chemically cross-linked hydrogel layer for HUVEC encapsulation, and the relatively stiff, acellular, photo-cross-linked hydrogel for retention of cell-laden microvasculature above. This dual-layer hydrogel construct enabled a lasting HUVEC aggregate-induced microvascular network due to the combination of stable substrate, enriched cell adhesion molecules, and extracellular matrix proteins. We tested the dual-layer hydrogel construct in a mouse model of hind-limb ischemia, where the HUVEC aggregate-induced microvascular networks significantly enhanced blood perfusion rate to ischemic legs and decreased tissue necrosis compared with both no treatment and

  9. Enzyme responsive GAG-based natural-synthetic hybrid hydrogel for tunable growth factor delivery and stem cell differentiation.

    Science.gov (United States)

    Anjum, Fraz; Lienemann, Philipp S; Metzger, Stéphanie; Biernaskie, Jeff; Kallos, Michael S; Ehrbar, Martin

    2016-05-01

    We describe an enzymatically formed chondroitin sulfate (CS) and poly(ethylene glycol) (PEG) based hybrid hydrogel system, which by tuning the architecture and composition of modular building blocks, allows the application-specific tailoring of growth factor delivery and cellular responses. CS, a negatively charged sulfate-rich glycosaminoglycan of the extracellular matrix (ECM), known for its growth factor binding and stem cell regulatory functions, is used as a starting material for the engineering of this biomimetic materials platform. The functionalization of CS with transglutaminase factor XIII specific substrate sequences is utilized to allow cross-linking of CS with previously described fibrin-mimetic TG-PEG hydrogel precursors. We show that the hydrogel network properties can be tuned by varying the degree of functionalization of CS as well as the ratio and concentrations of PEG and CS precursors. Taking advantage of TG-PEG hydrogel, compatible tagged bio-functional building blocks, including RGD peptides or matrix metalloproteinase sensitive domains, can be incorporated on demand allowing the three-dimensional culture and expansion of human bone marrow mesenchymal stem cells (BM-MSCs). The binding of bone morphogenetic protein-2 (BMP-2) in a CS concentration dependent manner and the BMP-2 release mediated osteogenic differentiation of BM-MSCs indicate the potential of CS-PEG hybrid hydrogels to promote regeneration of bone tissue. Their modular design allows facile incorporation of additional signaling elements, rendering CS-PEG hydrogels a highly flexible platform with potential for multiple biomedical applications. PMID:26914701

  10. Polymer-conjugated albumin and fibrinogen composite hydrogels as cell scaffolds designed for affinity-based drug delivery.

    Science.gov (United States)

    Oss-Ronen, Liat; Seliktar, Dror

    2011-01-01

    Serum albumin was conjugated to poly-(ethylene glycol) (PEG) and cross-linked to form mono-PEGylated albumin hydrogels. These hydrogels were used as a basis for drug carrying tissue engineering scaffold materials, based on the natural affinity of various drugs and compounds for the tethered albumin in the polymer network. The results of the drug release validation experiments showed that the release kinetics of the drugs from the mono-PEGylated albumin hydrogels were controlled by the molecular weight (MW) of PEG conjugated to the albumin protein, the drug MW and its inherent affinity for albumin. Composite hydrogels containing both mono-PEGylated albumin and PEGylated fibrinogen were used specifically for three-dimensional (3D) cell culture scaffolds, with inherent bioactivity, proteolytic biodegradability and controlled drug release properties. The specific characteristics of these complex hydrogels were governed by the ratio between the concentrations of each protein, the addition of free PEG diacrylate (PEG DA) molecules to the hydrogel matrix and the MW of the PEG conjugated to each protein. Comprehensive characterization of the drug release and degradation properties, as well as 3D cell culture experiments using these composite materials, demonstrated the effectiveness of this combined approach in creating a tissue engineering scaffold material with controlled drug release features. PMID:20643230

  11. In situ collagen assembly for integrating microfabricated three-dimensional cell-seeded matrices

    Science.gov (United States)

    Gillette, Brian M.; Jensen, Jacob A.; Tang, Beixian; Yang, Genevieve J.; Bazargan-Lari, Ardalan; Zhong, Ming; Sia, Samuel K.

    2008-08-01

    Microscale fabrication of three-dimensional (3D) extracellular matrices (ECMs) can be used to mimic the often inhomogeneous and anisotropic properties of native tissues and to construct in vitro cellular microenvironments. Cellular contraction of fibrous natural ECMs (such as fibrin and collagen I) can detach matrices from their surroundings and destroy intended geometry. Here, we demonstrate in situ collagen fibre assembly (the nucleation and growth of new collagen fibres from preformed collagen fibres at an interface) to anchor together multiple phases of cell-seeded 3D hydrogel-based matrices against cellular contractile forces. We apply this technique to stably interface multiple microfabricated 3D natural matrices (containing collagen I, Matrigel, fibrin or alginate); each phase can be seeded with cells and designed to permit cell spreading. With collagen-fibre-mediated interfacing, microfabricated 3D matrices maintain stable interfaces (the individual phases do not separate from each other) over long-term culture (at least 3weeks) and support spatially restricted development of multicellular structures within designed patterns. The technique enables construction of well-defined and stable patterns of a variety of 3D ECMs formed by diverse mechanisms (including temperature-, ion- and enzyme-mediated crosslinking), and presents a simple approach to interface multiple 3D matrices for biological studies and tissue engineering.

  12. Production of Prednisolone by Pseudomonas oleovorans Cells Incorporated Into PVP/PEO Radiation Crosslinked Hydrogels

    Directory of Open Access Journals (Sweden)

    Abeer Abd El-Hady

    2004-01-01

    Full Text Available In order to rise the yield of prednisolone from hydrocortisone, the Pseudomonas oleovorans cells were entrapped into radiation crosslinked poly (vinyl pyrrolidone/poly(ethylene oxide (PVP/PEO hydrogel of different gel contents. The factors affecting the gel content and swelling behavior of the polymeric gel, such as polymer composition, polymer blend concentration, and irradiation doses, were investigated. The formation of gels having a good strength with the ability to retain a desirable amount of water in their three-dimensional network can be achieved by using PVP/PEO copolymer of composition (90:10 and concentration of 15% prepared at 20 kGy irradiation dose. At these conditions the prepared hydrogel is considered the most favorable one that gave the highest hydrocortisone bioconversion and prednisolone yield, 81% and 62.8%, respectively. The improvement of prednisolone yield was also achieved by increasing substrate concentration. Maximum hydrocortisone bioconversion (86.44 was obtained at 18 hours by using substrate concentration of 30 mg. Reusability of immobilized Pseudomonas oleovorans entrapped into PVP/PEO copolymer hydrogel was studied. The results indicated that the transformation capacity of hydrocortisone to prednisolone highly increased by the repeated use of copolymer for 4 times. This was accompanied by an increase in prednisolone yield to 89% and the bioconversion of hydrocortisone was 98.8%.

  13. Excimer laser micropatterning of freestanding thermo-responsive hydrogel layers for cells-on-chip applications

    International Nuclear Information System (INIS)

    We report a novel reliable and repeatable technologic manufacturing protocol for the realization of micro-patterned freestanding hydrogel layers based on thermo-responsive poly-(N-isopropyl)acrylamide (PNIPAAm), which have potential to be employed as temperature-triggered smart surfaces for cells-on-chip applications. PNIPAAm-based films with controlled mechanical properties and different thicknesses (100–300 µm thickness) were prepared by injection compression moulding at room temperature. A 9 × 9 array of 20 µm diameter through-holes is machined by means of the KrF excimer laser on dry PNIPAAm films which are physically attached to flat polyvinyl chloride (PVC) substrates. Machining parameters, such as fluence and number of shots, are optimized in order to achieve highly resolved features. Micro-structured freestanding films are then easily obtained after hydrogels are detached from PVC by gradually promoting the film swelling in ethanol. In the PNIPAAm water-swollen state, the machined holes’ diameter approaches a slight larger value (30 µm) according to the measured hydrogel swelling ratio. Thermo-responsive behaviour and through-hole tapering characterization are carried out by metrology measurements using an optical inverted and confocal microscope setup, respectively. After the temperature of freestanding films is raised above 32 °C, we observe that the shrinkage of the whole through-hole array occurs, thus reducing the holes’ diameter to less than a half its original size (about 15 µm) as a consequence of the film dehydration. Different holes’ diameters (10 and 30 µm) are also obtained on dry hydrogel employing suitable projection masks, showing similar shrinking behaviour when hydrated and undergone thermo-response tests. Thermo-responsive PNIPAAm-based freestanding layers could then be integrated with other suitable micro-fabricated thermoplastic components in order to preliminary test their feasibility in operating as temperature

  14. Biofunctionalization of conductive hydrogel coatings to support olfactory ensheathing cells at implantable electrode interfaces.

    Science.gov (United States)

    Hassarati, Rachelle T; Marcal, Helder; John, L; Foster, R; Green, Rylie A

    2016-05-01

    Mechanical discrepancies between conventional platinum (Pt) electrodes and neural tissue often result in scar tissue encapsulation of implanted neural recording and stimulating devices. Olfactory ensheathing cells (OECs) are a supportive glial cell in the olfactory nervous system which can transition through glial scar tissue while supporting the outgrowth of neural processes. It has been proposed that this function can be used to reconnect implanted electrodes with the target neural pathways. Conductive hydrogel (CH) electrode coatings have been proposed as a substrate for supporting OEC survival and proliferation at the device interface. To determine an ideal CH to support OECs, this study explored eight CH variants, with differing biochemical composition, in comparison to a conventional Pt electrodes. All CH variants were based on a biosynthetic hydrogel, consisting of poly(vinyl alcohol) and heparin, through which the conductive polymer (CP) poly(3,4-ethylenedioxythiophene) was electropolymerized. The biochemical composition was varied through incorporation of gelatin and sericin, which were expected to provide cell adherence functionality, supporting attachment, and cell spreading. Combinations of these biomolecules varied from 1 to 3 wt %. The physical, electrical, and biological impact of these molecules on electrode performance was assessed. Cyclic voltammetry and electrochemical impedance spectroscopy demonstrated that the addition of these biological molecules had little significant effect on the coating's ability to safely transfer charge. Cell attachment studies, however, determined that the incorporation of 1 wt % gelatin in the hydrogel was sufficient to significantly increase the attachment of OECs compared to the nonfunctionalized CH. © 2015 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 104B: 712-722, 2016. PMID:26248597

  15. Programmed cell death of Ulmus pumila L. seeds during aging

    Institute of Scientific and Technical Information of China (English)

    Yulan ZHANG; Ming ZHANG; Fang LI; Xiaofeng WANG

    2008-01-01

    The programmed cell death (PCD) character-istics of Ulmus pumila L. seeds were investigated. The seeds were treated at a high temperature of 37℃ and 100% relative humidity for six days. DAPI (4'6-diami-dino-2-phenylindole) staining revealed that the aging treatment induced condensation and margination of chro-matin, as well as the formation of apoptotic bodies. DNA electrophoresis results of U. pumila seeds on an agarose gel showed a characteristic "ladder" pattern. Levels of electrolyte leakage of seed cells showed that membranes retained their integral form during almost the entire aging time. There was an immediate increase in the production rate of superoxide anion (O2-) and in the amount of hydrogen peroxide (H2O2), which remained at a μmol level. All of these common characteristics indicate that seed aging can be classified as PCD.

  16. [Research Progress in Seeding Cells of Peripheral Nerve].

    Science.gov (United States)

    Shi, Gengqiang; Hu, Yi

    2015-04-01

    Seeding cells play an important role in the peripheral nerve damage repair. Seeding cells studied conse- quently in peripheral nerve are Schwann cells, bone marrow mesenchymal stem cells and neural stem cells. Schwann cells, the first seeding cells, are various unique glial cells in the peripheral nervous system, which can form the myelin sheath for insulation and package of the neuron projecting axons in the peripheral nervous system so that the conduction velocity of the nerve signal was accelerated. It can be proved that Schwann cells played an important role in the maintenance of peripheral nerve function and in the regeneration process after peripheral nerve injury. The second, bone marrow mesenchymal stem cells are the various mesenchymal stem cells mainly exist in the systemic connective tissues and organs. These functional stem cells are often studied at present, and it has been found that they have exuberant proliferation and differentiation potentials. Neural stem cells, mentioned the third in sequence, are the kind of pluripotent cells with multi-directional differentiation, which could conduct the self-renewal function, and generate and differentiate neurons, astrocytes and oligodendrocytes through asymmetric cell division. These three types of seed cells are discussed in this paper. PMID:26211274

  17. Three-dimensional hydrogel cell culture systems for modeling neural tissue

    Science.gov (United States)

    Frampton, John

    Two-dimensional (2-D) neural cell culture systems have served as physiological models for understanding the cellular and molecular events that underlie responses to physical and chemical stimuli, control sensory and motor function, and lead to the development of neurological diseases. However, the development of three-dimensional (3-D) cell culture systems will be essential for the advancement of experimental research in a variety of fields including tissue engineering, chemical transport and delivery, cell growth, and cell-cell communication. In 3-D cell culture, cells are provided with an environment similar to tissue, in which they are surrounded on all sides by other cells, structural molecules and adhesion ligands. Cells grown in 3-D culture systems display morphologies and functions more similar to those observed in vivo, and can be cultured in such a way as to recapitulate the structural organization and biological properties of tissue. This thesis describes a hydrogel-based culture system, capable of supporting the growth and function of several neural cell types in 3-D. Alginate hydrogels were characterized in terms of their biomechanical and biochemical properties and were functionalized by covalent attachment of whole proteins and peptide epitopes. Methods were developed for rapid cross-linking of alginate hydrogels, thus permitting the incorporation of cells into 3-D scaffolds without adversely affecting cell viability or function. A variety of neural cell types were tested including astrocytes, microglia, and neurons. Cells remained viable and functional for longer than two weeks in culture and displayed process outgrowth in 3-D. Cell constructs were created that varied in cell density, type and organization, providing experimental flexibility for studying cell interactions and behavior. In one set of experiments, 3-D glial-endothelial cell co-cultures were used to model blood-brain barrier (BBB) structure and function. This co-culture system was

  18. On-chip single cell funneling operated by microfabricated thermo-responsive hydrogel layers

    International Nuclear Information System (INIS)

    We present a multilayer microfluidic system having a KrF excimer laser micro-patterned thermo-responsive poly-(N-isopropyl)-acrylamide (PNIPAAm) based hydrogel layer integrated as a freestanding component that operates as a temperature-triggered cell isolation actuator for single cell assays applications. When the system is assembled, the size of the laser machined micro-through-hole (entrance diameter is 150 μm, while exit hole diameter varies from 10 to 80 μm) can be reversibly modulated as a consequence of the polymer volumetric phase transition induced by heating the device above the critical temperature of 32 °C; as a result of the polymer water loss, the shrinkage of the layer caused the hole to homogeneously shrink, thus reducing its original size to about 40% in the polymer collapsed state. This actuation mechanism was exploited to trap a cellular sample in the shrunken exit hole on the top of the hydrogel layer by applying a negative pressure across the film when the system is brought to 37 °C. Subsequently, the funneling of the trapped cell took place through the orifice when the polymer’s natural relaxation at room temperature toward its initial state occurred; the functionality of the device was proved using optical microscopy to monitor MG63 cells as a model cell line during the funneling through the size-modulating structure. (paper)

  19. On-chip single cell funneling operated by microfabricated thermo-responsive hydrogel layers

    Science.gov (United States)

    Santaniello, Tommaso; Yan, Yunsong; Tocchio, Alessandro; Martello, Federico; Gassa, Federico; Webb, Patrick; Zhao, Weiwei; Tamplenizza, Margherita; Schulte, Carsten; Liu, Yang; Hutt, David; Milani, Paolo; Conway, Paul; Lenardi, Cristina

    2015-07-01

    We present a multilayer microfluidic system having a KrF excimer laser micro-patterned thermo-responsive poly-(N-isopropyl)-acrylamide (PNIPAAm) based hydrogel layer integrated as a freestanding component that operates as a temperature-triggered cell isolation actuator for single cell assays applications. When the system is assembled, the size of the laser machined micro-through-hole (entrance diameter is 150 μm, while exit hole diameter varies from 10 to 80 μm) can be reversibly modulated as a consequence of the polymer volumetric phase transition induced by heating the device above the critical temperature of 32 °C as a result of the polymer water loss, the shrinkage of the layer caused the hole to homogeneously shrink, thus reducing its original size to about 40% in the polymer collapsed state. This actuation mechanism was exploited to trap a cellular sample in the shrunken exit hole on the top of the hydrogel layer by applying a negative pressure across the film when the system is brought to 37 °C. Subsequently, the funneling of the trapped cell took place through the orifice when the polymer’s natural relaxation at room temperature toward its initial state occurred; the functionality of the device was proved using optical microscopy to monitor MG63 cells as a model cell line during the funneling through the size-modulating structure.

  20. Cell-seeded polyurethane-fibrin structures – A possible system for intervertebral disc regeneration

    Directory of Open Access Journals (Sweden)

    C Mauth

    2009-10-01

    Full Text Available Nowadays, intervertebral disc (IVD degeneration is one of the principal causes of low back pain involving high expense within the health care system. The long-term goal is the development of a medical treatment modality focused on a more biological regeneration of the inner nucleus pulposus (NP. Hence, interest in the endoscopic implantation of an injectable material took center stage in the recent past. We report on the development of a novel polyurethane (PU scaffold as a mechanically stable carrier system for the reimplantation of expanded autologous IVD-derived cells (disc cells to stimulate regenerative processes and restore the chondrocyte-like tissue within the NP. Primary human disc cells were seeded into newly developed PU spheroids which were subsequently encapsulated in fibrin hydrogel. The study aims to analyze adhesion properties, proliferation capacity and phenotypic characterization of these cells. Polymerase chain reaction was carried out to detect the expression of genes specifically expressed by native IVD cells. Biochemical analyses showed an increased DNA content, and a progressive enhancement of total collagen and glycosaminoglycans (GAG was observed during cell culture. The results suggest the synthesis of an appropriate extracellular matrix as well as a stable mRNA expression of chondrogenic and/or NP specific markers. In conclusion, the data presented indicate an alternative medical approach to current treatment options of degenerated IVD tissue.

  1. Salivary gland acinar cells regenerate functional glandular structures in modified hydrogels

    Science.gov (United States)

    Pradhan, Swati

    Xerostomia, a condition resulting from irradiation of the head and neck, affects over 40,000 cancer patients each year in the United States. Direct radiation damage of the acinar cells that secrete fluid and protein results in salivary gland hypofunction. Present medical management for xerostomia for patients treated for upper respiratory cancer is largely ineffective. Patients who have survived their terminal diagnosis are often left with a diminished quality of life and are unable to enjoy the simple pleasures of eating and drinking. This project aims to ultimately reduce human suffering by developing a functional implantable artificial salivary gland. The goal was to create an extracellular matrix (ECM) modified hyaluronic acid (HA) based hydrogel culture system that allows for the growth and differentiation of salivary acinar cells into functional acini-like structures capable of secreting large amounts of protein and fluid unidirectionally and to ultimately engineer a functional artificial salivary gland that can be implanted into an animal model. A tissue collection protocol was established and salivary gland tissue was obtained from patients undergoing head and neck surgery. The tissue specimen was assessed by histology and immunohistochemistry to establish the phenotype of normal salivary gland cells including the native basement membranes. Hematoxylin and eosin staining confirmed normal glandular tissue structures including intercalated ducts, striated ducts and acini. alpha-Amylase and periodic acid schiff stain, used for structures with a high proportion of carbohydrate macromolecules, preferentially stained acinar cells in the tissue. Intercalated and striated duct structures were identified using cytokeratins 19 and 7 staining. Myoepithelial cells positive for cytokeratin 14 were found wrapped around the serous and mucous acini. Tight junction components including ZO-1 and E-cadherin were present between both ductal and acinar cells. Ductal and acinar

  2. Engineering hyaluronic acid hydrogel degradation to control cellular interactions and adult stem cell fate in 3D

    Science.gov (United States)

    Khetan, Sudhir

    The design and implementation of extracellular matrix (ECM)-mimetic hydrogels for tissue engineering (TE) applications requires an intensive understanding of cell-material interactions, including matrix remodeling and stem cell differentiation. However, the influence of microenvironmental cues, e.g., matrix biodegradability, on cell behavior in vitro has not been well studied in the case of direct cell encapsulation within 3-dimensional (3D) hydrogels. To address these issues, a facile sequential crosslinking technique was developed that provides spatial and temporal control of 3D hydrogel degradability to investigate the importance of material design on cell behavior. Specifically, hydrogels were synthesized from hyaluronic acid (HA) macromers in a sequential process: (1) a primary Michael-type addition crosslinking using cell adhesive and matrix metalloprotease (MMP)-degradable oligopeptides to consume a portion of total reactive groups and resulting in "-UV" hydrogels permissive to cell-mediated degradation, followed by (2) a secondary, light initiated free-radical crosslinking to consume remaining reactive groups and "switch" the network to a non-degradable structure ("+UV") via the addition of non-degradable kinetic chains. Using this approach, we demonstrated control of encapsulated hMSC spreading by varying the crosslink type (i.e., the relative hydrogel biodegradability), including with spatial control. Upon incubation with bipotential soluble differentiation factors, these same degradation-mediated spreading cues resulted in an hMSC differentiation fate switch within -UV versus +UV environments. Follow-up studies demonstrated that degradation-mediated traction generation, rather than matrix mechanics or cell morphology, is the critical biophysical signal determining hMSC fate. Sequentially crosslinked HA hydrogels were also studied for the capacity to support remodeling by in vivo and ex vivo tissues, including with spatial control, toward tissue

  3. Cell-type specific four-component hydrogel.

    Directory of Open Access Journals (Sweden)

    Timo Aberle

    Full Text Available In the field of regenerative medicine we aim to develop implant matrices for specific tissue needs. By combining two per se, cell-permissive gel systems with enzymatic crosslinkers (gelatin/transglutaminase and fibrinogen/thrombin to generate a blend (technical term: quattroGel, an unexpected cell-selectivity evolved. QuattroGels were porous and formed cavities in the cell diameter range, possessed gelation kinetics in the minute range, viscoelastic properties and a mechanical strength appropriate for general cell adhesion, and restricted diffusion. Cell proliferation of endothelial cells, chondrocytes and fibroblasts was essentially unaffected. In contrast, on quattroGels neither endothelial cells formed vascular tubes nor did primary neurons extend neurites in significant amounts. Only chondrocytes differentiated properly as judged by collagen isoform expression. The biophysical quattroGel characteristics appeared to leave distinct cell processes such as mitosis unaffected and favored differentiation of sessile cells, but hampered differentiation of migratory cells. This cell-type selectivity is of interest e.g. during articular cartilage or invertebral disc repair, where pathological innervation and angiogenesis represent adverse events in tissue engineering.

  4. Cell-type specific four-component hydrogel.

    Science.gov (United States)

    Aberle, Timo; Franke, Katrin; Rist, Elke; Benz, Karin; Schlosshauer, Burkhard

    2014-01-01

    In the field of regenerative medicine we aim to develop implant matrices for specific tissue needs. By combining two per se, cell-permissive gel systems with enzymatic crosslinkers (gelatin/transglutaminase and fibrinogen/thrombin) to generate a blend (technical term: quattroGel), an unexpected cell-selectivity evolved. QuattroGels were porous and formed cavities in the cell diameter range, possessed gelation kinetics in the minute range, viscoelastic properties and a mechanical strength appropriate for general cell adhesion, and restricted diffusion. Cell proliferation of endothelial cells, chondrocytes and fibroblasts was essentially unaffected. In contrast, on quattroGels neither endothelial cells formed vascular tubes nor did primary neurons extend neurites in significant amounts. Only chondrocytes differentiated properly as judged by collagen isoform expression. The biophysical quattroGel characteristics appeared to leave distinct cell processes such as mitosis unaffected and favored differentiation of sessile cells, but hampered differentiation of migratory cells. This cell-type selectivity is of interest e.g. during articular cartilage or invertebral disc repair, where pathological innervation and angiogenesis represent adverse events in tissue engineering. PMID:24475174

  5. Oxygen-Purged Microfluidic Device to Enhance Cell Viability in Photopolymerized PEG Hydrogel Microparticles.

    Science.gov (United States)

    Xia, Bingzhao; Krutkramelis, Kaspars; Oakey, John

    2016-07-11

    Encapsulating cells within biocompatible materials is a widely used strategy for cell delivery and tissue engineering. While cells are commonly suspended within bulk hydrogel-forming solutions during gelation, substantial interest in the microfluidic fabrication of miniaturized cell encapsulation vehicles has more recently emerged. Here, we utilize multiphase microfluidics to encapsulate cells within photopolymerized picoliter-volume water-in-oil droplets at high production rates. The photoinitiated polymerization of polyethylene glycol diacrylate (PEGDA) is used to continuously produce solid particles from aqueous liquid drops containing cells and hydrogel forming solution. It is well understood that this photoinitiated addition reaction is inhibited by oxygen. In contrast to bulk polymerization in which ambient oxygen is rapidly and harmlessly consumed, allowing the polymerization reaction to proceed, photopolymerization within air permeable polydimethylsiloxane (PDMS) microfluidic devices allows oxygen to be replenished by diffusion as it is depleted. This sustained presence of oxygen and the consequential accumulation of peroxy radicals produce a dramatic effect upon both droplet polymerization and post-encapsulation cell viability. In this work we employ a nitrogen microjacketed microfluidic device to purge oxygen from flowing fluids during photopolymerization. By increasing the purging nitrogen pressure, oxygen concentration was attenuated, and increased post-encapsulation cell viability was achieved. A reaction-diffusion model was used to predict the cumulative intradroplet concentration of peroxy radicals, which corresponded directly to post-encapsulation cell viability. The nitrogen-jacketed microfluidic device presented here allows the droplet oxygen concentration to be finely tuned during cell encapsulation, leading to high post-encapsulation cell viability. PMID:27285343

  6. Biomimetic macroporous hydrogels: protein ligand distribution and cell response to the ligand architecture in the scaffold.

    Science.gov (United States)

    Savina, Irina N; Dainiak, Maria; Jungvid, Hans; Mikhalovsky, Sergey V; Galaev, Igor Yu

    2009-01-01

    Macroporous hydrogels (MHs), cryogels, are a new type of biomaterials for tissue engineering that can be produced from any natural or synthetic polymer that forms a gel. Synthetic MHs are rendered bioactive by surface or bulk modifications with extracellular matrix components. In this study, cell response to the architecture of protein ligands, bovine type-I collagen (CG) and human fibrinogen (Fg), immobilised using different methods on poly(2-hydroxyethyl methacrylate) (pHEMA) macroporous hydrogels (MHs) was analysed. Bulk modification was performed by cross-linking cryo-co-polymerisation of HEMA and poly(ethylene glycol)diacrylate (PEGA) in the presence of proteins (CG/pHEMA and Fg/pHEMA MHs). The polymer surface was modified by covalent immobilisation of the proteins to the active epoxy (ep) groups present on pHEMA after hydrogel fabrication (CG-epHEMA and Fg-epHEMA MHs). The concentration of proteins in protein/pHEMA and protein-epHEMA MHs was 80-85 and 130-140 mug/ml hydrogel, respectively. It was demonstrated by immunostaining and confocal laser scanning microscopy that bulk modification resulted in spreading of CG in the polymer matrix and spot-like distribution of Fg. On the contrary, surface modification resulted in spot-like distribution of CG and uniform spreading of Fg, which evenly coated the surface. Proliferation rate of fibroblasts was higher on MHs with even distribution of the ligands, i.e., on Fg-epHEMA and CG/pHEMA. After 30 days of growth, fibroblasts formed several monolayers and deposited extracellular matrix filling the pores of these MHs. The best result in terms of cell proliferation was obtained on Fg-epHEMA. The ligands displayed on surface of these scaffolds were in native conformation, while in bulk-modified CG/pHEMA MHs most of the proteins were buried inside the polymer matrix and were less accessible for interactions with specific antibodies and cells. The method used for MH modification with bioligands strongly affects spatial

  7. Control of hyperbranched structure of polycaprolactone/poly(ethylene glycol) polyurethane block copolymers by glycerol and their hydrogels for potential cell delivery.

    Science.gov (United States)

    Li, Zibiao; Li, Jun

    2013-11-27

    A series of biodegradable amphiphilic polyurethane block copolymers with hyperbranched structure were synthesized by copolymerizing poly(ε-caprolactone) (PCL) and poly(ethylene glycol) (PEG) together with glycerol. The copolymers were characterized, and their composition and branch length were varied with the feeding ratio between PCL, PEG, and glycerol used. Hydrogels were formed from these copolymers by swelling of water at low polymer concentrations. The hydrogels were thixotropic, and their dynamic viscoelastic properties were dependent on the copolymer composition, branch length, and polymer concentration. Hydrolytic degradation of the hydrogels was evaluated by mass loss and changes in molecular structures. The porous morphology of the hydrogels provided good permeability for gas and nutrition. Together with the tunable rheological properties, the hydrogels were found to be suitable for 3D living cell encapsulation and delivery. The morphology of the solid copolymers was semicrystalline, while the hydrogels were totally amorphous without crystallinity, providing a mild aqueous environment for living cells. When the encapsulated cells were recovered from the hydrogels followed by subculture, they showed good cell viability and proliferation ability. The results indicate that the hyperbranched copolymers hydrogels developed in this work may be promising candidates for potential injectable cell delivery application. PMID:24175974

  8. Cell-Type Specific Four-Component Hydrogel

    OpenAIRE

    Timo Aberle; Katrin Franke; Elke Rist; Karin Benz; Burkhard Schlosshauer

    2014-01-01

    In the field of regenerative medicine we aim to develop implant matrices for specific tissue needs. By combining two per se, cell-permissive gel systems with enzymatic crosslinkers (gelatin/transglutaminase and fibrinogen/thrombin) to generate a blend (technical term: quattroGel), an unexpected cell-selectivity evolved. QuattroGels were porous and formed cavities in the cell diameter range, possessed gelation kinetics in the minute range, viscoelastic properties and a mechanical strength appr...

  9. Patterned cell arrays and patterned co-cultures on polydopamine-modified poly(vinyl alcohol) hydrogels

    International Nuclear Information System (INIS)

    Live cell arrays are an emerging tool that expand traditional 2D in vitro cell culture, increasing experimental precision and throughput. A patterned cell system was developed by combining the cell-repellent properties of polyvinyl alcohol hydrogels with the cell adhesive properties of self-assembled films of dopamine (polydopamine). It was shown that polydopamine could be patterned onto spin-cast polyvinyl alcohol hydrogels by microcontact printing, which in turn effectively patterned the growth of several cell types (HeLa, human embryonic kidney, human umbilical vein endothelial cells (HUVEC) and prostate cancer). The cells could be patterned in geometries down to single-cell confinement, and it was demonstrated that cell patterns could be maintained for at least 3 weeks. Furthermore, polydopamine could be used to modify poly(vinyl alcohol) in situ using a cell-compatible deposition buffer (1 mg mL−1 dopamine in 25 mM tris with a physiological salt balance). The treatment switched the PVA hydrogel from cell repellent to cell adhesive. Finally, by combining microcontact printing and in situ deposition of polydopamine, patterned co-cultures of the same cell type (HeLa/HeLa) and dissimilar cell types (HeLa/HUVEC) were realized through simple chemistry and could be studied over time. The combination of polyvinyl alcohol and polydopamine was shown to be an attractive route to versatile, patterned cell culture experiments with minimal infrastructure requirements and low complexity. (paper)

  10. Critical early events in hematopoietic cell seeding and engraftment.

    Directory of Open Access Journals (Sweden)

    Jerry Stein

    2005-12-01

    Full Text Available Durable hematopoietic stem cell engraftment requires efficient homing to and seeding in the recipient bone marrow. Dissection of cellular and molecular mechanisms by retrospective analysis of functional engraftment studies imposes severe limitations on the understanding of the early stages of this process. We have established an experimental approach for in vivo functional imaging of labeled cells at the level of recipient bone marrow in real time. The adhesive interaction of hematopoietic cells with the bone marrow stroma evolves as the most important early event. Adhesion to the marrow, rather than the vascular endothelium, determines the efficiency of both homing and seeding, and is absolutely essential to maintain cell viability in the marrow. Seeding and engraftment may be improved either by bypassing homing or by localized transplant of a large number of cells in a relatively small marrow space. There is functional redundancy in the molecular pathways that mediate the cell-stroma interaction, such that blockage of a single pathway has only minor effect on homing and seeding. We hypothesize that successfully seeding-engrafting cells undergo extensive phenotypic changes as a consequence of interaction with the stroma, without engaging in rapid proliferation. Surprisingly, Fas-ligand appears to promote hematopoietic cell engraftment by immunomodulatory and trophic effects.

  11. Hydrogel limits stem cell dispersal in the deaf cochlea: implications for cochlear implants

    Science.gov (United States)

    Nayagam, Bryony A.; Backhouse, Steven S.; Cimenkaya, Cengiz; Shepherd, Robert K.

    2012-12-01

    Auditory neurons provide the critical link between a cochlear implant and the brain in deaf individuals, therefore their preservation and/or regeneration is important for optimal performance of this neural prosthesis. In cases where auditory neurons are significantly depleted, stem cells (SCs) may be used to replace the lost population of neurons, thereby re-establishing the critical link between the periphery (implant) and the brain. For such a therapy to be therapeutically viable, SCs must be differentiated into neurons, retained at their delivery site and damage caused to the residual auditory neurons minimized. Here we describe the transplantation of SC-derived neurons into the deaf cochlea, using a peptide hydrogel to limit their dispersal. The described approach illustrates that SCs can be delivered to and are retained within the basal turn of the cochlea, without a significant loss of endogenous auditory neurons. In addition, the tissue response elicited from this surgical approach was restricted to the surgical site and did not extend beyond the cochlear basal turn. Overall, this approach illustrates the feasibility of targeted cell delivery into the mammalian cochlea using hydrogel, which may be useful for future cell-based transplantation strategies, for combined treatment with a cochlear implant to restore function.

  12. Cell type dependent morphological adaptation in polyelectrolyte hydrogels governs chondrogenic fate.

    Science.gov (United States)

    Raghothaman, Deepak; Leong, Meng Fatt; Lim, Tze Chiun; Wan, Andrew C A; Ser, Zheng; Lee, Eng Hin; Yang, Zheng

    2016-01-01

    Repair of critical-size articular cartilage defects typically involves delivery of cells in biodegradable, 3D matrices. Differences in the developmental status of mesenchymal stem cells (MSCs) and terminally differentiated mature chondrocytes might be a critical factor in engineering appropriate 3D matrices for articular cartilage tissue engineering. This study examined the relationship between material-driven early cell morphological adaptations and chondrogenic outcomes, by studying the influence of aligned collagen type I (Col I) presentation on chondrocytes and MSC in interfacial polyelectrolyte complexation (IPC)-based hydrogels. In the absence of Col I, both chondrocytes and MSCs adopted rounded cell morphology and formed clusters, with chondrocyte clusters favoring the maintenance of hyaline phenotype, while MSC clusters differentiated to fibro-superficial zone-like chondrocytes. Encapsulated chondrocytes in IPC-Col I hydrogel adopted a fibroblastic morphology forming fibro-superficial zone-like phenotype, which could be reversed by inhibiting actin polymerization using cytochalasin D (CytD). In contrast, adoption of fibroblastic morphology by encapsulated MSCs in IPC-Col I facilitated superior chondrogenesis, generating a mature, hyaline neocartilage tissue. CytD treatment abrogated the elongation of MSCs and brought about a single cell-like state, resulting in insignificant chondrogenic differentiation, underscoring the essential requirement of providing matrix environments that are amenable to cell-cell interactions for robust MSC chondrogenic differentiation. Our study demonstrates that MSCs and culture-expanded chondrocytes favour differential microenvironmental niches and emphasizes the importance of designing biomaterials that meet cell type-specific requirements, in adopting chondrocyte or MSC-based approaches for regenerating hyaline, articular cartilage. PMID:27041648

  13. Hidrogel como substituto da irrigação complementar em viveiro telado de mudas de cafeeiro Hydrogel as a substitute for irrigation in screened seed nursery coffee

    Directory of Open Access Journals (Sweden)

    Patricia Angélica Alves Marques

    2013-01-01

    Full Text Available O cafeeiro, em sua fase inicial de mudas, requer um adequado suprimento de água, pois o estresse hídrico pode causar reduções no crescimento e subsequentemente na produção em campo. A hipótese deste trabalho foi que o uso do hidrogel como substituto da irrigação de mudas de café cv. 'Iapar 59' proporciona mudas de qualidade igual ou superior àquelas irrigadas. O experimento foi conduzido em viveiro telado (50% sombrite em Presidente Prudente - SP - de fevereiro a outubro de 2008. Utilizou-se o delineamento inteiramente casualizado, com cinco tratamentos (sem polímero e irrigado diariamente; 0,0; 1,0; 2,0 e 3,0g por saco de polietileno sem irrigação e 20 repetições. Realizaram-se seis avaliações periódicas: número de folhas (NF, matéria seca da parte aérea (MSPA e raízes (MSR; comprimento da parte aérea (CPA e raízes (CR e MSPA/MSR. Para as condições do ensaio, o uso do hidrogel na dose de 2g por saco de polietileno proporcionou mudas de mesma qualidade que aquelas irrigadas. A relação MSPA/MSR foi superior para o tratamento irrigado.The coffee seedlings require an adequate water supply because the water stress can cause reductions in growth and subsequently in the production field. The hypothesis of this research was that the hydrogel used as a substitute for the irrigation of seedlings of 'Iapar 59' coffee provides quality equal or higher seedling irrigated. The experiment was conducted in a screened seed nursery (50 shading in Presidente Prudente city, São Paulo State, Brazil, since February to October 2008. The statistical design was completely randomized, with 5 treatments (without polymer and without irrigation; 0.0; 1.0; 2.0 and 3.0g of hydrogel per polythene bag without irrigation and 20 repetitions. We conducted six periodic evaluations: number of leaves (NF, dry matter of aerial part (MSPA and roots (MSR; length of aerial part (CPA and roots (CR and the MSPA/MSR. Under test conditions, the use of hydrogel

  14. Carbon dots incorporated polymeric hydrogels as multifunctional platform for imaging and induction of apoptosis in lung cancer cells.

    Science.gov (United States)

    Sachdev, Abhay; Matai, Ishita; Gopinath, P

    2016-05-01

    Multifunctional hydrogels offer a seemingly efficient system for delivery of drugs and bioimaging modalities. The present study deals with the facile development of chitosan-based hydrogel formulation composed of highly fluorescent carbon dots (CDs) and loaded with a model anticancer drug, 5-Fluorouracil (5-FU). Herein, CDs were embedded firmly within the hydrogel matrices (CD-HY) via non-covalent interactions during the ionic cross-linking reaction. Furthermore, these hydrogels could effectively encapsulate 5-FU through hydrophobic interactions to form 5-FU@CD-HY. In this way, it was possible to combine the merits of both CDs and 5-FU on a common platform for monitoring the cellular uptake as well as therapeutic effects. Field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA) illustrated the porous nature and formation of 5-FU@CD-HY. Besides, functional characteristics of 5-FU@CD-HY such as surface area, mechanical strength, swelling behavior and drug release were investigated. In vitro studies revealed the multifunctional aspects of 5-FU@CD-HY in monitoring the cellular uptake and inflicting apoptosis in A549 cells. Green fluorescence of CDs in 5-FU@CD-HY aided the qualitative and quantitative assessment of cellular uptake. In addition to this, the fluorescence of CDs could be used to detect apoptosis instigated by 5-FU, eliminating the need for multiplex dyes. Induction of apoptosis in 5-FU@CD-HY treated cells was evidenced by changes in cell cycle distributions and visualization of characteristic apoptotic bodies through FE-SEM. Apoptotic gene expression studies further elucidate the molecular mechanism involved in eliciting apoptosis. Thus, hydrogels mediated integration of fluorescent CDs with chemotherapeutic agents provides a new dimension for the potential use of hydrogels in cancer theranostics. PMID:26854583

  15. Properties of hydrogel materials used for entrapment of microbial cells in production of fermented beverages.

    Science.gov (United States)

    Navrátil, Marián; Gemeiner, Peter; Klein, Jaroslav; Sturdík, Ernest; Malovíková, Anna; Nahálka, Jozef; Vikartovská, Alica; Dömény, Zoltán; Smogrovicová, Daniela

    2002-05-01

    Approaches using immobilized biological materials are very promising for application in different branches of the food industry, especially in the production of fermented beverages. Materials tested by our team for the process of entrapment belong to the family of charged polysaccharides able to form beaded hydrogels by ionotropic gelation (e.g. alginate, pectate, kappa-carrageenan) and synthetic polymers (e.g. polyvinyl alcohol) forming bead- and lens-shaped hydrogels by thermal sol/gel transition. Concentration of a gel, conditions and instrumentation of gelation process, bead and size distribution, porosity, diffusion properties, mechanical, storage and operational stability, and many other parameters were followed and optimized. Our work has been oriented especially to practical applications of immobilized cells. Brewing yeast cells were successfully immobilized by entrapment materials and used in a process of batch and continual production of beer, including primary and secondary fermentation of wort. Other applications include continual production of ethanol by fermentation of different saccharide substrates (molasses, glucose syrup, wheat hydrolysate), mead and non-alcoholic beverages production. PMID:12066875

  16. Development of a Biomimetic Chondroitin Sulfate-modified Hydrogel to Enhance the Metastasis of Tumor Cells

    Science.gov (United States)

    Liu, Yang; Wang, Shujun; Sun, Dongsheng; Liu, Yongdong; Liu, Yang; Wang, Yang; Liu, Chang; Wu, Hao; Lv, Yan; Ren, Ying; Guo, Xin; Sun, Guangwei; Ma, Xiaojun

    2016-01-01

    Tumor metastasis with resistance to anticancer therapies is the main cause of death in cancer patients. It is necessary to develop reliable tumor metastasis models that can closely recapitulate the pathophysiological features of the native tumor tissue. In this study, chondroitin sulfate (CS)-modified alginate hydrogel beads (ALG-CS) are developed to mimic the in vivo tumor microenvironment with an abnormally increased expression of CS for the promotion of tumor cell metastasis. The modification mechanism of CS on alginate hydrogel is due to the cross-linking between CS and alginate molecules via coordination of calcium ions, which enables ALG-CS to possess significantly different physical characteristics than the traditional alginate beads (ALG). And quantum chemistry calculations show that in addition to the traditional egg-box structure, novel asymmetric egg-box-like structures based on the interaction between these two kinds of polymers are also formed within ALG-CS. Moreover, tumor cell metastasis is significantly enhanced in ALG-CS compared with that in ALG, as confirmed by the increased expression of MMP genes and proteins and greater in vitro invasion ability. Therefore, ALG-CS could be a convenient and effective 3D biomimetic scaffold that would be used to construct standardized tumor metastasis models for tumor research and anticancer drug screening. PMID:27432752

  17. A Neuroprotective Sericin Hydrogel As an Effective Neuronal Cell Carrier for the Repair of Ischemic Stroke.

    Science.gov (United States)

    Wang, Zheng; Wang, Jian; Jin, Yang; Luo, Zhen; Yang, Wen; Xie, Hongjian; Huang, Kai; Wang, Lin

    2015-11-11

    Ischemic stroke causes extensive cellular loss that impairs brain functions, resulting in severe disabilities. No effective treatments are currently available for brain tissue regeneration. The need to develop effective therapeutic approaches for treating stroke is compelling. A tissue engineering approach employing a hydrogel carrying both cells and neurotrophic cytokines to damaged regions is an encouraging alternative for neuronal repair. However, this approach is often challenged by low in vivo cell survival rate, and low encapsulation efficiency and loss of cytokines. To address these limitations, we propose to develop a biomaterial that can form a matrix capable of improving in vivo survival of transplanted cells and reducing in vivo loss of cytokines. Here, we report that using sericin, a natural protein from silk, we have fabricated a genipin-cross-linked sericin hydrogel (GSH) with porous structure and mild swelling ratio. The GSH supports the effective attachment and growth of neurons in vitro. Strikingly, our data reveal that sericin protein is intrinsically neurotrophic and neuroprotective, promoting axon extension and branching as well as preventing primary neurons from hypoxia-induced cell death. Notably, these functions are inherited by the GSH's degradation products, which might spare a need of incorporating costly cytokines. We further demonstrate that this neurotrophic effect is dependent on the Lkb1-Nuak1 pathway, while the neuroprotective effect is realized through regulating the Bcl-2/Bax protein ratio. Importantly, when transplanted in vivo, the GSH gives a high cell survival rate and allows the cells to continuously proliferate. Together, this work unmasks the neurotrophic and neuroprotective functions for sericin and provides strong evidence justifying the GSH's suitability as a potential neuronal cell delivery vehicle for ischemic stroke repair. PMID:26478947

  18. Selective pattern of cancer cell accumulation and growth using UV modulating printing of hydrogels.

    Science.gov (United States)

    Yang, Wenguang; Yu, Haibo; Wei, Fanan; Li, Gongxin; Wang, Yuechao; Liu, Lianqing

    2015-12-01

    Fabrication of extracellular microenvironment for cancer cell growth in vitro is an indispensable technique to precisely control the cell spatial arrangement and proliferation for cell-behavior research. Current micropatterning methods usually require relatively complicated operations, which makes it difficult to investigate the effects of different cell growth patterns. This manuscript proposes a DMD-based projection technique to quickly pattern a poly(ethylene) glycol diacrylate (PEGDA)-based hydrogel on a common glass substrate. Using this method, we can effectively control the growth patterns of cells. Compared with these traditional methods which employ digital dynamic mask, polymerization of PEGDA solution can be used to create arbitrary shaped microstructures with high efficiency, flexibility and repeatability. The duration of UV exposure is less than 10 s through controlling the projected illumination pattern. The ability of patterned PEGDA-coated film to hinder cell adhesion makes it possible to control area over which cells attach. In our experiments, we take advantage of the blank area to pattern cells, which allows cells to grow in various pre-designed shapes and sizes. And the patterning cells have a high viability after culturing for several days. Interestingly, we found that the restricted space could stiffen and strengthen the cells. These results indicate that cells and extracellular microenvironment can influence each other. PMID:26458559

  19. Scalable Production of Glioblastoma Tumor-initiating Cells in 3 Dimension Thermoreversible Hydrogels.

    Science.gov (United States)

    Li, Qiang; Lin, Haishuang; Wang, Ou; Qiu, Xuefeng; Kidambi, Srivatsan; Deleyrolle, Loic P; Reynolds, Brent A; Lei, Yuguo

    2016-01-01

    There is growing interest in developing drugs that specifically target glioblastoma tumor-initiating cells (TICs). Current cell culture methods, however, cannot cost-effectively produce the large numbers of glioblastoma TICs required for drug discovery and development. In this paper we report a new method that encapsulates patient-derived primary glioblastoma TICs and grows them in 3 dimension thermoreversible hydrogels. Our method allows long-term culture (~50 days, 10 passages tested, accumulative ~>10(10)-fold expansion) with both high growth rate (~20-fold expansion/7 days) and high volumetric yield (~2.0 × 10(7) cells/ml) without the loss of stemness. The scalable method can be used to produce sufficient, affordable glioblastoma TICs for drug discovery. PMID:27549983

  20. Type II collagen-hyaluronan hydrogel – a step towards a scaffold for intervertebral disc tissue engineering

    Directory of Open Access Journals (Sweden)

    L Calderon

    2010-09-01

    Full Text Available Intervertebral disc regeneration strategies based on stem cell differentiation in combination with the design of functional scaffolds is an attractive approach towards repairing/regenerating the nucleus pulposus. The specific aim of this study was to optimise a composite hydrogel composed of type II collagen and hyaluronic acid (HA as a carrier for mesenchymal stem cells. Hydrogel stabilisation was achieved by means of 1-ethyl-3(3-dimethyl aminopropyl carbodiimide (EDC and N-hydroxysuccinimide (NHS cross-linking. Optimal hydrogel properties were determined by investigating different concentrations of EDC (8mM, 24mM and 48mM. Stable hydrogels were obtained independent of the concentration of carbodiimide used. The hydrogels cross-linked by the lowest concentration of EDC (8mM demonstrated high swelling properties. Additionally, improved proliferation of seeded rat mesenchymal stem cells (rMSCs and hydrogel stability levels in culture were observed with this 8mM cross-linked hydrogel. Results from this study indicate that EDC/NHS (8mM cross-linked type II collagen/HA hydrogel was capable of supporting viability of rMSCs, and furthermore their differentiation into a chondrogenic lineage. Further investigations should be conducted to determine its potential as scaffold for nucleus pulposus regeneration/repair.

  1. Dextran based highly conductive hydrogel polysulfide electrolyte for efficient quasi-solid-state quantum dot-sensitized solar cells

    International Nuclear Information System (INIS)

    Highlights: ► Dextran based hydrogel is first used to prepare quasi-solid-state polysulfide electrolyte for quantum dot-sensitized solar cells. ► The ion conductivity of hydrogel electrolyte shows almost the same value as the liquid electrolyte. ► The liquid state at elevated temperature of hydrogel electrolyte allows for a good contact between electrolyte and CdS/CdSe co-sensitized TiO2 photoanode. ► The hydrogel electrolyte based cell exhibits slightly lower power conversion efficiency than that of liquid electrolyte based cell. ► The dynamic electron transfer mechanism in hydrogel electrolyte based cell is examined in detail by EIS and CIMPS/IMVS. -- Abstract: Highly conductive hydrogel polysulfide electrolyte is first fabricated using dextran as gelator and used as quasi-solid-state electrolyte for quantum dot-sensitized solar cells (QDSSCs). The hydrogel electrolyte with gelator concentration of 15 wt% shows almost the same conductivity as the liquid one. Moreover, its liquid state at elevated temperature allow for the well penetration into the pores in electrodeposited CdS/CdSe co-sensitized TiO2 photoanode. This gel electrolyte based QDSSC exhibits power conversion efficiency (η) of 3.23% under AG 1.5 G one sun (100 mW cm−2) illumination, slightly lower than that of liquid electrolyte based cell (3.69%). The dynamic electron transfer mechanism of the gel and liquid electrolyte based QDSSC are examined by electrochemical impedance spectroscopy (EIS) and controlled intensity modulated photocurrent/photovoltage spectroscopy (CIMPS/IMVS). It is found that the electron transport in gel electrolyte based cell is much faster than the liquid electrolyte based cell but it tends to recombine more easily than the latter. However, these differences fade away with increasing the light intensity, showing declining electron collection efficiency at higher light intensity illumination. As a result, a conversion efficiency of 4.58% is obtained for the gel

  2. Control of growth factor binding and release in bisphosphonate functionalized hydrogels guides rapid differentiation of precursor cells in vitro.

    Science.gov (United States)

    Kootala, Sujit; Zhang, Yu; Ghalib, Sara; Tolmachev, Vladimir; Hilborn, Jöns; Ossipov, Dmitri A

    2016-02-01

    An in situ cross-linkable hyaluronan hydrogel functionalized with bisphosphonate (BP) groups allows tunable release of bone morphogenetic protein-2 (BMP-2) determined by the amount of BP groups. The high affinity of matrix-anchored BP groups towards BMP-2 permits guided differentiation of entrapped progenitor cells in 3-D cultures. PMID:26610690

  3. Alginate hydrogel enriched with enamel matrix derivative to target osteogenic cell differentiation in TiO2 scaffolds

    DEFF Research Database (Denmark)

    Pullisaar, Helen; Verket, Anders; Szoke, Krisztina; Tiainen, Hanna; Haugen, Håvard J; Brinchmann, Jan E; Reseland, Janne E; Østrup, Esben

    2015-01-01

    various donors on titanium dioxide (TiO2) scaffolds coated with an alginate hydrogel enriched with enamel matrix derivative. Cells were harvested for quantitative reverse transcription polymerase chain reaction on days 14 and 21, and medium was collected on days 2, 14, and 21 for protein analyses. Neither...

  4. Control of growth factor binding and release in bisphosphonate functionalized hydrogels guides rapid diff erentiation of precursor cells in vitro

    OpenAIRE

    Kootala, Sujit; Zhang, Yu; Ghalib, Sara; Tolmachev, Vladmir; Hilborn, Jöns; Ossipov, Dmitri

    2016-01-01

    An in situ cross-linkable hyaluronan hydrogel functionalized with bisphosphonate (BP) groups allows tunable release of bone morphogenetic protein-2 (BMP-2) determined by the amount of BP groups. The high affinity of matrix-anchored BP groups towards BMP-2 permits guided differentiation of entrapped progenitor cells in 3-D cultures.

  5. Interactions of human primary immune cells with nanoparticles, two-dimensional micropatterns, hydrogels and three-dimensional nanofibres

    OpenAIRE

    Bartneck, Matthias

    2010-01-01

    The response of immune cells to any biomaterial determines its biocompatibility. This study aimed to identify the immunomodulatory properties of biomaterials from four different fields exhibiting various chemical, geometrical and morphological properties: nanoparticles, two-dimensional micropatterned structures, hydrogel with functional endgroups and three-dimensional nanofibers. It was shown in how far chemical, topographical and morphological properties of biomaterials affect the immune res...

  6. Repair of osteochondral defects with biodegradable hydrogel composites encapsulating marrow mesenchymal stem cells in a rabbit model.

    NARCIS (Netherlands)

    Guo, X.; Park, H.; Young, S.; Kretlow, J.D.; Beucken, J.J.J.P. van den; Baggett, L.S.; Tabata, Y.; Kasper, F.K.; Mikos, A.G.; Jansen, J.A.

    2010-01-01

    This work investigated the delivery of marrow mesenchymal stem cells (MSCs), with or without the growth factor transforming growth factor-beta1 (TGF-beta1), from biodegradable hydrogel composites on the repair of osteochondral defects in a rabbit model. Three formulations of oligo(poly(ethylene glyc

  7. Screening of hyaluronic acid-poly(ethylene glycol) composite hydrogels to support intervertebral disc cell biosynthesis using artificial neural network analysis.

    Science.gov (United States)

    Jeong, Claire G; Francisco, Aubrey T; Niu, Zhenbin; Mancino, Robert L; Craig, Stephen L; Setton, Lori A

    2014-08-01

    Hyaluronic acid (HA)-poly(ethylene glycol) (PEG) composite hydrogels have been widely studied for both cell delivery and soft tissue regeneration applications. A very broad range of physical and biological properties have been engineered into HA-PEG hydrogels that may differentially affect cellular "outcomes" of survival, synthesis and metabolism. The objective of this study was to rapidly screen multiple HA-PEG composite hydrogel formulations for an effect on matrix synthesis and behaviors of nucleus pulposus (NP) and annulus fibrosus (AF) cells of the intervertebral disc (IVD). A secondary objective was to apply artificial neural network analysis to identify relationships between HA-PEG composite hydrogel formulation parameters and biological outcome measures for each cell type of the IVD. Eight different hydrogels were developed from preparations of thiolated HA (HA-SH) and PEG vinylsulfone (PEG-VS) macromers, and used as substrates for NP and AF cell culture in vitro. Hydrogel mechanical properties ranged from 70 to 489kPa depending on HA molecular weight, and measures of matrix synthesis, metabolite consumption and production and cell morphology were obtained to study relationships to hydrogel parameters. Results showed that NP and AF cell numbers were highest upon the HA-PEG hydrogels formed from the lower-molecular-weight HA, with evidence of higher sulfated glycosaminoglycan production also upon lower-HA-molecular-weight composite gels. All cells formed more multi-cell clusters upon any HA-PEG composite hydrogel as compared to gelatin substrates. Formulations were clustered into neurons based largely on their HA molecular weight, with few effects of PEG molecular weight observed on any measured parameters. PMID:24859415

  8. Ca-alginate hydrogel mechanical transformations--the influence on yeast cell growth dynamics.

    Science.gov (United States)

    Pajić-Lijaković, Ivana; Plavsić, Milenko; Bugarski, Branko; Nedović, Viktor

    2007-05-01

    A mathematical model was formulated to describe yeast cell growth within the Ca-alginate microbead during air-lift bioreactor cultivation. Model development was based on experimentally obtained data for the intra-bead cell concentration profile, after reached the equilibrium state, as well as, total yeast cell concentration per microbed and microbead volume as function of time. Relatively uniform cell concentration in the carrier matrix indicated that no internal nutrient diffusion limitations, but microenvironmental restriction, affected dominantly the dynamics of cell growth. Also interesting phenomenon of very different rates of cell number growth during cultivation is observed. After some critical time, the growth rate of cell colonies decreased drastically, but than suddenly increased again under all other experimental condition been the same. It is interpreted as disintegration of gel network and opening new free space for growth of cell clusters. These complex phenomena are modeled using the thermodynamical, free energy formalism. The particular form of free energy functional is proposed to describe various kinds of interactions, which affected the dynamics of cell growth and cause pseudo-phase transition of hydrogel. The good agreement of experimentally obtained data and model predictions are obtained. In that way the model provides both, the quantitative tools for further technological optimization of the process and deeper insight into dynamics of cell growth mechanism. PMID:17331608

  9. Corneal cell adhesion to contact lens hydrogel materials enhanced via tear film protein deposition.

    Directory of Open Access Journals (Sweden)

    Claire M Elkins

    Full Text Available Tear film protein deposition on contact lens hydrogels has been well characterized from the perspective of bacterial adhesion and viability. However, the effect of protein deposition on lens interactions with the corneal epithelium remains largely unexplored. The current study employs a live cell rheometer to quantify human corneal epithelial cell adhesion to soft contact lenses fouled with the tear film protein lysozyme. PureVision balafilcon A and AirOptix lotrafilcon B lenses were soaked for five days in either phosphate buffered saline (PBS, borate buffered saline (BBS, or Sensitive Eyes Plus Saline Solution (Sensitive Eyes, either pure or in the presence of lysozyme. Treated contact lenses were then contacted to a live monolayer of corneal epithelial cells for two hours, after which the contact lens was sheared laterally. The apparent cell monolayer relaxation modulus was then used to quantify the extent of cell adhesion to the contact lens surface. For both lens types, lysozyme increased corneal cell adhesion to the contact lens, with the apparent cell monolayer relaxation modulus increasing up to an order of magnitude in the presence of protein. The magnitude of this increase depended on the identity of the soaking solution: lenses soaked in borate-buffered solutions (BBS, Sensitive Eyes exhibited a much greater increase in cell attachment upon protein addition than those soaked in PBS. Significantly, all measurements were conducted while subjecting the cells to moderate surface pressures and shear rates, similar to those experienced by corneal cells in vivo.

  10. Three dimensional alginate-fucoidan composite hydrogel augments the chondrogenic differentiation of mesenchymal stromal cells.

    Science.gov (United States)

    Karunanithi, Puvanan; Murali, Malliga Raman; Samuel, Shani; Raghavendran, Hanumanantha Rao Balaji; Abbas, Azlina Amir; Kamarul, Tunku

    2016-08-20

    Presence of sulfated polysaccharides like heparan sulphate has often been implicated in the regulation of chondrogenesis. However, recently there has been a plethora of interest in the use of non-animal extracted analogs of heparan sulphate. Here we remodeled alginate (1.5%) by incorporating fucoidan (0.5%), a natural sulphated polysaccharide extracted from seaweeds to form a composite hydrogel (Al-Fu), capable of enhancing chondrogenesis of human mesenchymal stromal cells (hMSCs). We confirmed the efficiency of fucoidan incorporation by FTIR and EDX analysis. Further, its ability to support hMSC attachment and chondrogenic differentiation was confirmed by SEM, biochemical glycosaminoglycan quantification, real-time quantitative PCR and immunocytochemical analyses of chondrogenic markers Sox-9, Collagen II, Aggrecan and COMP. Effect of Al-Fu hydrogel on hMSC hypertrophy was also confirmed by the downregulation of hypertrophic genes Collagen X and Runx2. This composite scaffold can hence be used as a cartilage biomimetic biomaterial to drive hMSC chondrogenesis and for other cartilage repair based therapies. PMID:27178935

  11. Combination of fibrin-agarose hydrogels and adipose-derived mesenchymal stem cells for peripheral nerve regeneration

    Science.gov (United States)

    Carriel, Víctor; Garrido-Gómez, Juan; Hernández-Cortés, Pedro; Garzón, Ingrid; García-García, Salomé; Sáez-Moreno, José Antonio; Sánchez-Quevedo, María del Carmen; Campos, Antonio; Alaminos, Miguel

    2013-04-01

    Objective. The objective was to study the effectiveness of a commercially available collagen conduit filled with fibrin-agarose hydrogels alone or with fibrin-agarose hydrogels containing autologous adipose-derived mesenchymal stem cells (ADMSCs) in a rat sciatic nerve injury model. Approach. A 10 mm gap was created in the sciatic nerve of 48 rats and repaired using saline-filled collagen conduits or collagen conduits filled with fibrin-agarose hydrogels alone (acellular conduits) or with hydrogels containing ADMSCs (ADMSC conduits). Nerve regeneration was assessed in clinical, electrophysiological and histological studies. Main results. Clinical and electrophysiological outcomes were more favorable with ADMSC conduits than with the acellular or saline conduits, evidencing a significant recovery of sensory and motor functions. Histological analysis showed that ADMSC conduits produce more effective nerve regeneration by Schwann cells, with higher remyelination and properly oriented axonal growth that reached the distal areas of the grafted conduits, and with intensely positive expressions of S100, neurofilament and laminin. Extracellular matrix was also more abundant and better organized around regenerated nerve tissues with ADMSC conduits than those with acellular or saline conduits. Significance. Clinical, electrophysiological and histological improvements obtained with tissue-engineered ADMSC conduits may contribute to enhancing axonal regeneration by Schwann cells.

  12. Neuronal Differentiation of Induced Pluripotent Stem Cells on Surfactant Templated Chitosan Hydrogels.

    Science.gov (United States)

    Worthington, Kristan S; Green, Brian J; Rethwisch, Mary; Wiley, Luke A; Tucker, Budd A; Guymon, C Allan; Salem, Aliasger K

    2016-05-01

    The development of effective tissue engineering materials requires careful consideration of several properties beyond biocompatibility, including permeability and mechanical stiffness. While surfactant templating has been used for over a decade to control the physical properties of photopolymer materials, the potential benefit of this technique with regard to biomaterials has yet to be fully explored. Herein we demonstrate that surfactant templating can be used to tune the water uptake and compressive modulus of photo-cross-linked chitosan hydrogels. Interestingly, templating with quaternary ammonium surfactants also hedges against property fluctuations that occur with changing pH. Further, we demonstrate that, after adequate surfactant removal, these materials are nontoxic, support the attachment of induced pluripotent stem cells and facilitate stem cell differentiation to neuronal phenotypes. These results demonstrate the utility of surfactant templating for optimizing the properties of biomaterials intended for a variety of applications, including retinal regeneration. PMID:27008004

  13. Four Step Differentiation of Umbilical Cord Derived Mesenchymal Stem Cells Within Hydrogel Scaffold Into Hepatocytes

    Directory of Open Access Journals (Sweden)

    Saeed Azandeh

    2015-09-01

    Full Text Available Introduction: Due to increasing demand for liver tissue engineering, three-dimensional (3D liver cells culture techniques have been proposed. Therefore, the aim of the present study was to examine the cells isolation and expansion of umbilical cord derived mesenchymal stem cells and in vitro 2D and 3D hepatocyte differentiation.Alsofunctional characteristics of hepatocytes were analyzedMethods: The study performed in several phases. In the first umbilical cord derived mesenchymal stem cells obtained and isolated, thereafter cellss expanded. Determination of Immunophenotype using Flow. Cytometry performed by DAKO – Galaxy Hepatic differentiation UC-MSCs was performed by four step sequential method using FGF-4, ITS, HGF, dexamethasone, glucagon, OSM and TSA. Urea production was quantified by ELISA.Section of tissue constructs stained with hematoxyllin and eosin for histological examinationResults: MSCs isolated from umbilical cord expressed mesenchymal surface antigen such as CD73, but were negative against CD31. Several cell clusters mainly between the round cells were observed in alginate scaffold after 3d differentiation. Urea production was increased time- dependable and was significantly higher in the experimental group of 3D culture (P=0.001. Tissue construct of 3D culture revealed multicellular tissue with several euchromatin cell plates.Conclusion: The finding of the present study indicated that four step differentiation of umbilical cord derived mesenchymal stem cells within hydrogel scaffold induced functionally and morphologically characteristics of hepatocytes such as urea production and cell plates.

  14. RGDS-functionalized polyethylene glycol hydrogel-coated magnetic iron oxide nanoparticles enhance specific intracellular uptake by HeLa cells

    Directory of Open Access Journals (Sweden)

    Nazli C

    2012-04-01

    Full Text Available Caner Nazli1, Tugba Ipek Ergenc2, Yasemin Yar1, Havva Yagci Acar1,3, Seda Kizilel1,21Graduate School of Sciences and Engineering, Koç University, 2Department of Chemical and Biological Engineering, College of Engineering, Koç University, 3Department of Chemistry, Faculty of Arts and Sciences, Koç University, Istanbul, TurkeyAbstract: The objective of this study was to develop thin, biocompatible, and biofunctional hydrogel-coated small-sized nanoparticles that exhibit favorable stability, viability, and specific cellular uptake. This article reports the coating of magnetic iron oxide nanoparticles (MIONPs with covalently cross-linked biofunctional polyethylene glycol (PEG hydrogel. Silanized MIONPs were derivatized with eosin Y, and the covalently cross-linked biofunctional PEG hydrogel coating was achieved via surface-initiated photopolymerization of PEG diacrylate in aqueous solution. The thickness of the PEG hydrogel coating, between 23 and 126 nm, was tuned with laser exposure time. PEG hydrogel-coated MIONPs were further functionalized with the fibronectin-derived arginine-glycine-aspartic acid-serine (RGDS sequence, in order to achieve a biofunctional PEG hydrogel layer around the nanoparticles. RGDS-bound PEG hydrogel-coated MIONPs showed a 17-fold higher uptake by the human cervical cancer HeLa cell line than that of amine-coated MIONPs. This novel method allows for the coating of MIONPs with nano-thin biofunctional hydrogel layers that may prevent undesirable cell and protein adhesion and may allow for cellular uptake in target tissues in a specific manner. These findings indicate that the further biofunctional PEG hydrogel coating of MIONPs is a promising platform for enhanced specific cell targeting in biomedical imaging and cancer therapy.Keywords: PEG hydrogel, surface-initiated photopolymerization, nanoparticle encapsulation, agglomeration

  15. Effect of Nano-HA/Collagen Composite Hydrogels on Osteogenic Behavior of Mesenchymal Stromal Cells.

    Science.gov (United States)

    Hayrapetyan, Astghik; Bongio, Matilde; Leeuwenburgh, Sander C G; Jansen, John A; van den Beucken, Jeroen J J P

    2016-06-01

    This study aimed to comparatively evaluate the in vitro effect of nanosized hydroxyapatite and collagen (nHA/COL) based composite hydrogels (with different ratios of nHA and COL) on the behavior of human mesenchymal stromal cells (MSCs), isolated from either adipose tissue (AT-MSCs) or bone marrow (BM-MSCs). We hypothesized that (i) nHA/COL composite hydrogels would promote the osteogenic differentiation of MSCs in an nHA concentration dependent manner, and that (ii) AT-MSCs would show higher osteogenic potential compared to BM-MSCs, due to their earlier observed higher proliferation and osteogenic differentiation potential in 2D in vitro cultures [1]. The obtained results indicated that AT-MSCs show indeed high proliferation, differentiation and mineralization capacities in nHA/COL constructs compared to BM-MSCs, but this effect was irrespective of nHA concentration. Based on the results of alkaline phosphatase (ALP) activity and osteocalcin (OCN) protein level, the osteogenic differentiation of BM-MSCs started in the beginning of the culture period and for AT-MSCs at the end of the culture period. At a molecular level, both cell types showed high expression of osteogenic markers (bone morphogenic protein 2 [BMP2], runt-related transcription factor 2 [RUNX2], OCN or COL1) in both an nHA concentration and time dependent manner. In conclusion, AT-MSCs demonstrated higher osteogenic potential in nHA/COL based 3D micro-environments compared to BM-MSCs, in which proliferation and osteogenic differentiation were highly promoted in a time dependent manner, irrespective of nHA amount in the constructs. The fact that AT-MSCs showed high proliferation and mineralization potential is appealing for their application in future pre-clinical research as an alternative cell source for BM-MSCs. PMID:26803618

  16. Injectable skeletal muscle matrix hydrogel promotes neovascularization and muscle cell infiltration in a hindlimb ischemia model

    Directory of Open Access Journals (Sweden)

    JA DeQuach

    2012-06-01

    Full Text Available Peripheral artery disease (PAD currently affects approximately 27 million patients in Europe and North America, and if untreated, may progress to the stage of critical limb ischemia (CLI, which has implications for amputation and potential mortality. Unfortunately, few therapies exist for treating the ischemic skeletal muscle in these conditions. Biomaterials have been used to increase cell transplant survival as well as deliver growth factors to treat limb ischemia; however, existing materials do not mimic the native skeletal muscle microenvironment they are intended to treat. Furthermore, no therapies involving biomaterials alone have been examined. The goal of this study was to develop a clinically relevant injectable hydrogel derived from decellularized skeletal muscle extracellular matrix and examine its potential for treating PAD as a stand-alone therapy by studying the material in a rat hindlimb ischemia model. We tested the mitogenic activity of the scaffold’s degradation products using an in vitro assay and measured increased proliferation rates of smooth muscle cells and skeletal myoblasts compared to collagen. In a rat hindlimb ischemia model, the femoral artery was ligated and resected, followed by injection of 150 µL of skeletal muscle matrix or collagen 1 week post-injury. We demonstrate that the skeletal muscle matrix increased arteriole and capillary density, as well as recruited more desmin-positive and MyoD-positive cells compared to collagen. Our results indicate that this tissue-specific injectable hydrogel may be a potential therapy for treating ischemia related to PAD, as well as have potential beneficial effects on restoring muscle mass that is typically lost in CLI.

  17. 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. ...

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

    OpenAIRE

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

    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-li...

  19. Sustained presentation of BMP-2 enhances osteogenic differentiation of human adipose-derived stem cells in gelatin hydrogels.

    Science.gov (United States)

    Samorezov, Julia E; Headley, Emma B; Everett, Christopher R; Alsberg, Eben

    2016-06-01

    Human adipose-derived stem cells (hASCs) show great potential for healing bone defects. Bone morphogenetic protein-2 (BMP-2) has been reported to stimulate their osteogenic differentiation both in vitro and in vivo. Here, methacrylated gelatin (GelMA) hydrogels were evaluated as a system to deliver BMP-2 to encapsulated hASCs from two different donors, and BMP-2 delivered from the hydrogels was compared to BMP-2 presented exogenously in culture media. GelMA hydrogels were shown to provide sustained, localized presentation of BMP-2 due to electrostatic interactions between the growth factor and biomaterial after an initial burst release. Both donors exhibited similar responses to the loaded and exogenous growth factor; BMP-2 from the hydrogels had a statistically significant effect on hASC osteogenic differentiation compared to exogenous BMP-2. Expression of alkaline phosphatase was accelerated, and cells in hydrogels with loaded BMP-2 deposited more calcium at one, two, and four weeks than cells without BMP-2 or with the growth factor presented in the media. There were no statistically significant differences in calcium content between groups with 25, 50, or 100 µg/mL loaded BMP-2, suggesting that using a lower growth factor dose may be as effective as a higher loading amount in this system. Taken together, these findings suggest that controlled delivery of BMP-2 from the GelMA enhances its osteogenic bioactivity compared to free growth factor presented in the media. Thus, the GelMA system is a promising biomaterial for BMP-2-mediated hASC osteogenesis. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 104A: 1387-1397, 2016. PMID:26822338

  20. Fabrication and optimization of alginate hydrogel constructs for use in 3D neural cell culture

    International Nuclear Information System (INIS)

    Two-dimensional (2D) culture systems provide useful information about many biological processes. However, some applications including tissue engineering, drug transport studies, and analysis of cell growth and dynamics are better studied using three-dimensional (3D) culture systems. 3D culture systems can potentially offer higher degrees of organization and control of cell growth environments, more physiologically relevant diffusion characteristics, and permit the formation of more extensive 3D networks of cell-cell interactions. A 3D culture system has been developed using alginate as a cell scaffold, capable of maintaining the viability and function of a variety of neural cell types. Alginate was functionalized by the covalent attachment of a variety of whole proteins and peptide epitopes selected to provide sites for cell attachment. Alginate constructs were used to entrap a variety of neural cell types including astroglioma cells, astrocytes, microglia and neurons. Neural cells displayed process outgrowth over time in culture. Cell-seeded scaffolds were characterized in terms of their biochemical and biomechanical properties, effects on seeded neural cells, and suitability for use as 3D neural cell culture models.

  1. Fabrication and optimization of alginate hydrogel constructs for use in 3D neural cell culture

    Energy Technology Data Exchange (ETDEWEB)

    Frampton, J P; Hynd, M R; Shain, W [Department of Biomedical Sciences, School of Public Health, State University of New York at Albany, Albany, NY 12210 (United States); Shuler, M L, E-mail: jf7674@albany.edu [Department of Biomedical Engineering, 270 Olin Hall, Cornell University, Ithaca, NY 14850 (United States)

    2011-02-15

    Two-dimensional (2D) culture systems provide useful information about many biological processes. However, some applications including tissue engineering, drug transport studies, and analysis of cell growth and dynamics are better studied using three-dimensional (3D) culture systems. 3D culture systems can potentially offer higher degrees of organization and control of cell growth environments, more physiologically relevant diffusion characteristics, and permit the formation of more extensive 3D networks of cell-cell interactions. A 3D culture system has been developed using alginate as a cell scaffold, capable of maintaining the viability and function of a variety of neural cell types. Alginate was functionalized by the covalent attachment of a variety of whole proteins and peptide epitopes selected to provide sites for cell attachment. Alginate constructs were used to entrap a variety of neural cell types including astroglioma cells, astrocytes, microglia and neurons. Neural cells displayed process outgrowth over time in culture. Cell-seeded scaffolds were characterized in terms of their biochemical and biomechanical properties, effects on seeded neural cells, and suitability for use as 3D neural cell culture models.

  2. Culture of nucleus pulposus cells from intervertebral disc on self-assembling KLD-12 peptide hydrogel scaffold

    International Nuclear Information System (INIS)

    KLD-12 peptide is a new self-assembling biomaterial and it has been used as cell scaffold for cartilage repair. In this study, self-assembled KLD-12 peptide nanofiber was fabricated and the biocompatibility of this scaffold for nucleus pulposus (NP) cells was evaluated. The structure of this scaffold was characterized by atomic force microscopy (AFM). This hydrogel was structurally integral and homogeneous. KLD-12 peptide was able to self-assemble into nanofibers with a diameter of 10-30 nm (mean: 13.7 ± 4.7 nm) and a length of hundreds of nanometers. Two-week culture of rabbits NP cells in this scaffold showed that the self-assembled hydrogel maintained the live cell number by 93% and the cell viability increased gradually with the culture time. The expression of type II collagen mRNA was further confirmed by reverse transcription polymerase chain reaction (RT-PCR). The expression of type II collagen was high in the hydrogel, however, type I collagen expression was observed in few cells. Furthermore, GAG content increased gradually accompanied with the extension of culture time. In conclusion, this self-assembled nanofiber scaffold provided a conducive microenvironment for NP cell to survive and proliferate in vitro.

  3. Fibrin hydrogels for non-viral vector delivery in vitro.

    Science.gov (United States)

    des Rieux, Anne; Shikanov, Ariella; Shea, Lonnie D

    2009-06-01

    Fibrin based hydrogels have been employed in vitro as a scaffold to promote tissue formation and investigate underlying molecular mechanisms. These hydrogels support a variety of cellular processes, and are being developed to enhance the presentation of biological cues, or to tailor the biological cues for specific tissues. The presentation of these cues could alternatively be enhanced through gene delivery, which can be employed to induce the expression of tissue inductive factors in the local environment. This report investigates gene delivery within fibrin hydrogels for two in vitro models of tissue growth: i) cell encapsulation within and ii) cell seeding onto the hydrogel. Naked plasmid and lipoplexes can be efficiently entrapped within the hydrogel, and after 1 day in solution more than 70% of the entrapped DNA is retained within the gel, with a sustained release observed for at least 19 days. Encapsulated lipoplexes did not aggregate and retain their original size. Transgene expression in vitro by delivery of lipoplexes was a function of the fibrinogen and DNA concentration. For encapsulated cells, all cells had intracellular plasmid and transgene expression persisted for at least 10 days, with maximal levels achieved at day 1. For cell infiltration, expression levels were less than those observed for encapsulation, and expression increased throughout the culture period. The increasing expression levels suggest that lipoplexes retain their activity after encapsulation; however, interactions between fibrin and the lipoplexes likely limit internalization. The inclusion of non-viral vectors into fibrin-based hydrogels can be employed to induce transgene expression of encapsulated and infiltrating cells, and may be employed with in vitro models of tissue growth to augment the intrinsic bioactivity of fibrin. PMID:19232532

  4. Osteogenic induction of human bone marrow-derived mesenchymal progenitor cells in novel synthetic polymer-hydrogel matrices

    OpenAIRE

    Endres, M; Hutmacher, D.W.; Salgado, A. J.; Kaps, C; RINGE, J; Reis, R. L.; Sittinger, M; Brandwood, A.; Schantz, J. T.

    2003-01-01

    The aim of this project was to investigate the in vitro osteogenic potential of human mesenchymal progenitor cells in novel matrix architectures built by means of a three-dimensional bioresorbable synthetic framework in combination with a hydrogel. Human mesenchymal progenitor cells (hMPCs) were isolated from a human bone marrow aspirate by gradient centrifugation. Before in vitro engineering of scaffold-hMPC constructs, the adipogenic and osteogenic differentiation potential was demonstrated...

  5. Thermally triggered injectable hydrogel, which induces mesenchymal stem cell differentiation to nucleus pulposus cells: Potential for regeneration of the intervertebral disc.

    Science.gov (United States)

    Thorpe, A A; Boyes, V L; Sammon, C; Le Maitre, C L

    2016-05-01

    There is an urgent need for new therapeutic options for low back pain, which target degeneration of the intervertebral disc (IVD). Here, we investigated a pNIPAM hydrogel system, which is liquid at 39°C ex vivo, where following injection into the IVD, body temperature triggers gelation. The combined effects of hypoxia (5% O2) and the structural environment of the hydrogel delivery system on the differentiation of human mesenchymal stem cells (hMSCs), towards an NP cell phenotype was investigated. hMSCs were incorporated into the liquid hydrogel, the mixture solidified and cultured for up to 6weeks under 21% O2 or 5% O2 where viability was maintained. Immunohistochemistry revealed significant increases in NP matrix components: aggrecan; collagen type II and chondroitin sulphate after culture for 1week in 5% O2, accompanied by increased matrix staining for proteoglycans and collagen, observed histologically. NP markers HIF1α, PAX1 and FOXF1 were also significantly increased where hMSC were incorporated into hydrogels with accelerated expression observed when cultured in 5% O2. hMSCs cultured under hypoxic conditions, which mimic the native disc microenvironment, accelerate differentiation of hMSCs within the hydrogel system, towards the NP phenotype without the need for chondrogenic inducing medium or additional growth factors, thus simplifying the treatment strategy for the repair of IVD degeneration. PMID:26996377

  6. Synthetic Biodegradable Hydrogels with Excellent Mechanical Properties and Good Cell Adhesion Characteristics Obtained by the Combinatorial Synthesis of Photo-Cross-Linked Networks.

    Science.gov (United States)

    Zant, Erwin; Grijpma, Dirk W

    2016-05-01

    Major drawbacks of synthetic hydrogels are their poor mechanical properties and their limited ability to allow cell attachment and proliferation. By photo-cross-linking mixtures of dimethacrylate-functionalized oligomers (macromers) in a combinatorial manner in solution, synthetic hydrogels with high water uptake and the remarkable ability to promote cell adhesion and proliferation were prepared. A total of 255 different networks based on poly(trimethylene carbonate) (PTMC)-, poly(d,l-lactide) (PDLLA)-, poly(ε-caprolactone) (PCL)- and poly(ethylene glycol) (PEG) macromers were synthesized simultaneously and screened for their ability to allow the adhesion of human mesenchymal stem cells (hMSCs) in a high throughput-like manner. Of these networks, several hydrogels could be identified that were able to take up large amounts of water while at the same time allowed the adhesion of cells. By synthesizing these hydrogel networks anew and analyzing the cell adhesion and proliferation behavior of human mesenchymal stem cells to these synthetic hydrogels in more detail, it was confirmed that mixed-macromer hydrogel networks prepared from equal amounts of PTMC-dMA 4k, PDLLA-dMA 4k, PCL-dMA 4k, PEG-dMA 4k, and PEG-dMA 10k and hydrogel networks prepared from PTMC-dMA 4k, PDLLA 4k, PEG-dMA 4k, PTMC-dMA 10k and PEG-dMA 10k were highly hydrophilic (water uptake was respectively 181 ± 2 and 197 ± 18 wt % water) and allowed very good cell adhesion and proliferation. Furthermore, these networks were extremely resilient in the hydrated state, with tearing energies of respectively 0.64 ± 0.34 and 0.27 ± 0.04 kJ/m(2). This is much higher than other synthetic hydrogels described in literature and close to articular cartilage (1 kJ/m(2)). PMID:27077699

  7. JSR photolithography based microvessel scaffold fabrication and cell seeding.

    Science.gov (United States)

    Wang, Gou-Jen; Hsu, Yi-Feng; Hsu, Shan-Hui; Horng, Ray Hua

    2006-03-01

    A simple and inexpensive lithograph approach, in which the PMMA polymer was selected to be the substrate, the negative photoresist JSR was employed to form the microchannel structure, was adopted to fabricate the microvessel scaffold. In addition, a soft PDMS based microvessel scaffold was built by using a mold that was made up of the negative photoresist JSR. With O(2) plasma treatment, the PDMS based microvessel scaffold became more hydrophilic such that the cell culture could be easier to conduct. During cell culture, it was found that the fabricated scaffold enabled the bovine endothelial cells (BEC) to statically grow. However, the overall exchange of nutrient and oxygen was inefficient. Dynamic seeding by a novel apparatus was further conducted to have better circulation of culture medium. The bovine endothelial cells could successfully be cultivated in the microvessel scaffold by dynamic seeding. PMID:16491327

  8. Critical early events in hematopoietic cell seeding and engraftment.

    OpenAIRE

    Jerry Stein; Isaac Yaniv; Nadir Askenasy

    2005-01-01

    Durable hematopoietic stem cell engraftment requires efficient homing to and seeding in the recipient bone marrow. Dissection of cellular and molecular mechanisms by retrospective analysis of functional engraftment studies imposes severe limitations on the understanding of the early stages of this process. We have established an experimental approach for in vivo functional imaging of labeled cells at the level of recipient bone marrow in real time. The adhesive interaction of hematopoietic ce...

  9. Enhanced mechanical properties of thermosensitive chitosan hydrogel by silk fibers for cartilage tissue engineering

    Energy Technology Data Exchange (ETDEWEB)

    Mirahmadi, Fereshteh [Faculty of Biomedical Engineering, Amirkabir University of Technology, Tehran (Iran, Islamic Republic of); National Cell Bank of Iran, Pasteur Institute of Iran, Tehran (Iran, Islamic Republic of); Tafazzoli-Shadpour, Mohammad, E-mail: Tafazoli@aut.ac.ir [Faculty of Biomedical Engineering, Amirkabir University of Technology, Tehran (Iran, Islamic Republic of); Shokrgozar, Mohammad Ali, E-mail: mashokrgozar@pasteur.ac.ir [National Cell Bank of Iran, Pasteur Institute of Iran, Tehran (Iran, Islamic Republic of); Bonakdar, Shahin [National Cell Bank of Iran, Pasteur Institute of Iran, Tehran (Iran, Islamic Republic of)

    2013-12-01

    Articular cartilage has limited repair capability following traumatic injuries and current methods of treatment remain inefficient. Reconstructing cartilage provides a new way for cartilage repair and natural polymers are often used as scaffold because of their biocompatibility and biofunctionality. In this study, we added degummed chopped silk fibers and electrospun silk fibers to the thermosensitive chitosan/glycerophosphate hydrogels to reinforce two hydrogel constructs which were used as scaffold for hyaline cartilage regeneration. The gelation temperature and gelation time of hydrogel were analyzed by the rheometer and vial tilting method. Mechanical characterization was measured by uniaxial compression, indentation and dynamic mechanical analysis assay. Chondrocytes were then harvested from the knee joint of the New Zealand white rabbits and cultured in constructs. The cell proliferation, viability, production of glycosaminoglycans and collagen type II were assessed. The results showed that mechanical properties of the hydrogel were significantly enhanced when a hybrid with two layers of electrospun silk fibers was made. The results of GAG and collagen type II in cell-seeded scaffolds indicate support of the chondrogenic phenotype for chondrocytes with a significant increase in degummed silk fiber–hydrogel composite for GAG content and in two-layer electrospun fiber–hydrogel composite for Col II. It was concluded that these two modified scaffolds could be employed for cartilage tissue engineering. - Highlights: • Chitosan hydrogel composites fabricated by two forms of silk fiber • Silk fibers provide structural support for the hydrogel matrix. • The mechanical properties of hydrogel significantly improved by associating with silk. • Production of GAG and collagen type II was demonstrated within the scaffolds.

  10. Quantitative analysis of the effects of biofunctional and physical gradients on cell behavior in poly (ethylene glycol) diacrylate hydrogels

    Science.gov (United States)

    Turturro, Michael

    The continued enhancement of tissue engineered scaffolds relies on their ability to stimulate the formation of a stable microvascular network within the biomaterial. In vivo, the spatial presentation of immobilized extracellular matrix cues and matrix mechanical properties play an important role in directed and guided cell behavior and neovascularization. The overall goals of this thesis are to develop a technique for the generation of gradients of physical properties and incorporated biofunctionality within poly(ethylene glycol) diacrylate (PEGDA) scaffolds and to investigate the effects of these gradients on 3D cell invasion and neovascularization. To this end, a novel photopolymerization technique for generating spatial variations in matrix properties and incorporated biofunctionality within synthetic PEGDA hydrogels, perfusion-based frontal polymerization (PBFP), was developed. This technique relies on the controlled perfusion of a photoinitiator to a reaction chamber containing a precursor solution and results in the propagation of a polymer reaction front that travels through the monomer solution creating a gradient in hydrogel crosslinking. Manipulation of the magnitude of the gradient can be achieved through alterations in the polymerization conditions. Scaffolds with embedded gradients were designed and optimized based on a range of properties shown to support 2D cell adhesion, proliferation, and 3D vascular cell invasion in bulk photopolymerized hydrogels with homogeneous properties. An in vitro model of neovascularization was used to evaluate the effect of these gradients on vascular sprout formation. Sprout invasion in gradient hydrogels occurred bi-directionally with sprout alignment observed in the direction parallel to the gradient while control hydrogels with homogeneous properties resulted in uniform invasion. In PBFP gradient hydrogels, sprout length was found to be twice as long in the direction parallel to the gradient as compared to the

  11. Development of Hydrogel with Anti-Inflammatory Properties Permissive for the Growth of Human Adipose Mesenchymal Stem Cells

    Directory of Open Access Journals (Sweden)

    R. Sánchez-Sánchez

    2016-01-01

    Full Text Available Skin wound repair requires the development of different kinds of biomaterials that must be capable of restoring the damaged tissue. Type I collagen and chitosan have been widely used to develop scaffolds for skin engineering because of their cell-related signaling properties such as proliferation, migration, and survival. Collagen is the major component of the skin extracellular matrix (ECM, while chitosan mimics the structure of the native polysaccharides and glycosaminoglycans in the ECM. Chitosan and its derivatives are also widely used as drug delivery vehicles since they are biodegradable and noncytotoxic. Regulation of the inflammatory response is crucial for wound healing and tissue regeneration processes; and, consequently, the development of biomaterials such as hydrogels with anti-inflammatory properties is very important and permissive for the growth of cells. In the last years, it has been shown that mesenchymal stem cells have clinical importance in the treatment of different pathologies, for example, skin injuries. In this paper, we describe the anti-inflammatory activity of collagen type 1/chitosan/dexamethasone hydrogel, which is permissive for the culture of human adipose-derived mesenchymal stem cells (hADMSC. Our results show that hADMSC cultured in the hydrogel are viable, proliferate, and secrete the anti-inflammatory cytokine interleukin-10 (IL-10 but not the inflammatory cytokine Tumor Necrosis Factor-alpha (TNF-α.

  12. Cell-on-hydrogel platform made of agar and alginate for rapid, low-cost, multidimensional test of antimicrobial susceptibility.

    Science.gov (United States)

    Sun, Han; Liu, Zhengzhi; Hu, Chong; Ren, Kangning

    2016-08-01

    Antimicrobial resistance (AMR) is a rapidly increasing threat to the effective treatment of infectious diseases worldwide. The two major remedies include: (1) using narrow-spectrum antibiotics based on rapid diagnosis; and (2) developing new antibiotics. A key part of both remedies is the antimicrobial susceptibility test (AST). However, the current standard ASTs that monitor colony formation are costly and time-consuming and the new strategies proposed are not yet practical to be implemented. Herein, we report a strategy to fabricate whole-hydrogel microfluidic chips using alginate-doped agar. This agar-based microfabrication makes it possible to prepare inexpensive hydrogel devices, and allows a seamless link between microfluidics and conventional agar-based cell culture. Different from common microfluidic systems, in our system the cells are cultured on top of the device, similar to normal agar plate culture; on the other hand, the microfluidic channels inside the hydrogel allow precise generation of linear gradient of drugs, thus giving a better performance than the conventional disk diffusion method. Cells in this system are not exposed to any shear flow, which allows the reliable tracking of individual cells and AST results to be obtained within 2-3 hours. Furthermore, our system could test the synergistic effect of drugs through two-dimensional gradient generation. Finally, the platform could be directly implemented to new drug discovery and other applications wherein a fast, cost-efficient method for studying the response of microorganisms upon drug administration is desirable. PMID:27452345

  13. Characterizing natural hydrogel for reconstruction of three-dimensional lymphoid stromal network to model T-cell interactions.

    Science.gov (United States)

    Kim, Jiwon; Wu, Biming; Niedzielski, Steven M; Hill, Matthew T; Coleman, Rhima M; Ono, Akira; Shikanov, Ariella

    2015-08-01

    Hydrogels have been used in regenerative medicine because they provide a three-dimensional environment similar to soft tissues, allow diffusion of nutrients, present critical biological signals, and degrade via endogenous enzymatic mechanisms. Herein, we developed in vitro system mimicking cell-cell and cell-matrix interactions in secondary lymphoid organs (SLOs). Existing in vitro culture systems cannot accurately represent the complex interactions happening between T-cells and stromal cells in immune response. To model T-cell interaction in SLOs in vitro, we encapsulated stromal cells in fibrin, collagen, or fibrin-collagen hydrogels and studied how different mechanical and biological properties affect stromal network formation. Overall, fibrin supplemented with aprotinin was superior to collagen and fibrin-collagen in terms of network formation and promotion of T-cell penetration. After 8 days of culture, stromal networks formed through branching and joining with other adjacent cell populations. T-cells added to the newly formed stromal networks migrated and attached to stromal cells, similar to the T-cell zones of the lymph nodes in vivo. Our results suggest that the constructed three-dimensional lymphoid stromal network can mimic the in vivo environment and allow the modeling of T-cell interaction in SLOs. PMID:25649205

  14. 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

  15. Hydrogel Microwell Arrays Allow the Assessment of Protease-Associated Enhancement of Cancer Cell Aggregation and Survival

    Directory of Open Access Journals (Sweden)

    Dietmar W. Hutmacher

    2013-08-01

    Full Text Available Current routine cell culture techniques are only poorly suited to capture the physiological complexity of tumor microenvironments, wherein tumor cell function is affected by intricate three-dimensional (3D, integrin-dependent cell-cell and cell-extracellular matrix (ECM interactions. 3D cell cultures allow the investigation of cancer-associated proteases like kallikreins as they degrade ECM proteins and alter integrin signaling, promoting malignant cell behaviors. Here, we employed a hydrogel microwell array platform to probe using a high-throughput mode how ovarian cancer cell aggregates of defined size form and survive in response to the expression of kallikreins and treatment with paclitaxel, by performing microscopic, quantitative image, gene and protein analyses dependent on the varying microwell and aggregate sizes. Paclitaxel treatment increased aggregate formation and survival of kallikrein-expressing cancer cells and levels of integrins and integrin-related factors. Cancer cell aggregate formation was improved with increasing aggregate size, thereby reducing cell death and enhancing integrin expression upon paclitaxel treatment. Therefore, hydrogel microwell arrays are a powerful tool to screen the viability of cancer cell aggregates upon modulation of protease expression, integrin engagement and anti-cancer treatment providing a micro-scaled yet high-throughput technique to assess malignant progression and drug-resistance.

  16. 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.

  17. Poly (vinyl alcohol) hydrogel membrane as electrolyte for direct borohydride fuel cells

    Indian Academy of Sciences (India)

    N A Choudhury; S K Prashant; S Pitchumani; P Sridhar; A K Shukla

    2009-09-01

    A direct borohydride fuel cell (DBFC) employing a poly (vinyl alcohol) hydrogel membrane electrolyte (PHME) is reported. The DBFC employs an AB5 Misch metal alloy as anode and a goldplated stainless steel mesh as cathode in conjunction with aqueous alkaline solution of sodium borohydride as fuel and aqueous acidified solution of hydrogen peroxide as oxidant. Room temperature performances of the PHME-based DBFC in respect of peak power outputs; ex-situ cross-over of oxidant, fuel, anolyte and catholyte across the membrane electrolytes; utilization efficiencies of fuel and oxidant, as also cell performance durability are compared with a similar DBFC employing a Nafion®-117 membrane electrolyte (NME). Peak power densities of ∼30 and ∼40 mW cm-2 are observed for the DBFCs with PHME and NME, respectively. The crossover of NaBH4 across both the membranes has been found to be very low. The utilization efficiencies of NaBH4 and H2O2 are found to be ∼24 and ∼59%, respectively for the PHME-based DBFC; ∼18 and ∼62%, respectively for the NME-based DBFC. The PHME and NME-based DBFCs exhibit operational cell potentials of ∼ 1.2 and ∼ 1.4 V, respectively at a load current density of 10 mA cm-2 for ∼100 h.

  18. Comparative study on seeding methods of human bone marrow stromal cells in bone tissue engineering

    Institute of Scientific and Technical Information of China (English)

    齐欣; 刘建国; 常颖; 徐莘香

    2004-01-01

    Background In general the traditional static seeding method has its limitation while the dynamic seeding method reveals its advantages over traditional static method. We compared static and dynamic seeding method for human bone marrow stromal cells (hBMSCs) in bone tissue engineering.Methods DNA assay was used for detecting the maximal initial seeding concentration for static seeding. Dynamic and static seeding methods were compared, when scaffolds were loaded with hBMSCs at this maximal initial cell seeding concentration. Histology and scanning electron microscope (SEM) were examined to evaluate the distribution of cells inside the constructs. Markers encoding osteogenic genes were measured by fluorescent RT-PCR. The protocol for dynamic seeding of hBMSCs was also investigated.Results DNA assay showed that the static maximal initial seeding concentration was lower than that in dynamic seeding. Histology and SEM showed even distribution and spread of cells in the dynamically seeded constructs, while their statically seeded counterparts showed cell aggregation.Fluorescent RT-PCR again showed stronger osteogenic potential of dynamically seeded constructs.Conclusion dynamic seeding of hBMSCs is a promising technique in bone tissue engineering.

  19. Vitronectin-Based, Biomimetic Encapsulating Hydrogel Scaffolds Support Adipogenesis of Adipose Stem Cells.

    Science.gov (United States)

    Clevenger, Tracy N; Hinman, Cassidy R; Ashley Rubin, Rebekah K; Smither, Kate; Burke, Daniel J; Hawker, Craig J; Messina, Darin; Van Epps, Dennis; Clegg, Dennis O

    2016-04-01

    Soft tissue defects are relatively common, yet currently used reconstructive treatments have varying success rates, and serious potential complications such as unpredictable volume loss and reabsorption. Human adipose-derived stem cells (ASCs), isolated from liposuction aspirate have great potential for use in soft tissue regeneration, especially when combined with a supportive scaffold. To design scaffolds that promote differentiation of these cells down an adipogenic lineage, we characterized changes in the surrounding extracellular environment during adipogenic differentiation. We found expression changes in both extracellular matrix proteins, including increases in expression of collagen-IV and vitronectin, as well as changes in the integrin expression profile, with an increase in expression of integrins such as αVβ5 and α1β1. These integrins are known to specifically interact with vitronectin and collagen-IV, respectively, through binding to an Arg-Gly-Asp (RGD) sequence. When three different short RGD-containing peptides were incorporated into three-dimensional (3D) hydrogel cultures, it was found that an RGD-containing peptide derived from vitronectin provided strong initial attachment, maintained the desired morphology, and created optimal conditions for in vitro 3D adipogenic differentiation of ASCs. These results describe a simple, nontoxic encapsulating scaffold, capable of supporting the survival and desired differentiation of ASCs for the treatment of soft tissue defects. PMID:26956095

  20. Osteogenic differentiation of human bone marrow mesenchymal stem cells in hydrogel containing nacre powder.

    Science.gov (United States)

    Flausse, Alicia; Henrionnet, Christel; Dossot, Manuel; Dumas, Dominique; Hupont, Sébastien; Pinzano, Astrid; Mainard, Didier; Galois, Laurent; Magdalou, Jacques; Lopez, Evelyne; Gillet, Pierre; Rousseau, Marthe

    2013-11-01

    Nacre (or mother of pearl) can facilitate bone cell differentiation and can speed up their mineralization. Here we report on the capability of nacre to induce differentiation of human bone marrow mesenchymal stem cells (hBM-MSCs) and the production of extracellular matrix. hBM-MSCs were encapsulated in an alginate hydrogel containing different concentrations of powdered nacre and cultured in the same environment until Day 28. Analysis of osteogenic gene expression, histochemistry, second harmonic generation (SHG) microscopy, and Raman scattering spectroscopy were used to characterize the synthesis of the extracellular matrix. In the presence of nacre powder, a significant increase in matrix synthesis from D21 in comparison with pure alginate was observed. Histochemistry revealed the formation of a new tissue composed of collagen fibers in the presence of nacre (immunostaining and SHG), and hydroxyapatite crystals (Raman) in the alginate beads. These results suggest that nacre is efficient in hBM-MSCs differentiation, extracellular matrix production and mineralization in alginate 3D biomaterials. PMID:23554327

  1. Digital microfabrication of user-defined 3D microstructures in cell-laden hydrogels.

    Science.gov (United States)

    Soman, Pranav; Chung, Peter H; Zhang, A Ping; Chen, Shaochen

    2013-11-01

    Complex 3D interfacial arrangements of cells are found in several in vivo biosystems such as blood vasculature, renal glomeruli, and intestinal villi. Current tissue engineering techniques fail to develop suitable 3D microenvironments to evaluate the concurrent effects of complex topography and cell encapsulation. There is a need to develop new fabrication approaches that control cell density and distribution within complex 3D features. In this work, we present a dynamic projection printing process that allows rapid construction of complex 3D structures using custom-defined computer-aided-design (CAD) files. Gelatin-methacrylate (GelMA) constructs featuring user-defined spiral, pyramid, flower, and dome micro-geometries were fabricated with and without encapsulated cells. Encapsulated cells demonstrate good cell viability across all geometries both on the scaffold surface and internal to the structures. Cells respond to geometric cues individually as well as collectively throughout the larger-scale patterns. Time-lapse observations also reveal the dynamic nature of mechanical interactions between cells and micro-geometry. When compared to conventional cell-seeding, cell encapsulation within complex 3D patterned scaffolds provides long-term control over proliferation, cell morphology, and geometric guidance. Overall, this biofabrication technique offers a flexible platform to evaluate cell interactions with complex 3D micro-features, with the ability to scale-up towards high-throughput screening platforms. PMID:23686741

  2. Rapid prototyping of tough hydrogels with encapsulated stem cells for design of load-bearing tissues

    OpenAIRE

    Sycks, Dalton

    2014-01-01

    As the world’s population ages, regenerative medicine continues to rise in importance. An important aspect of this is developing the ability to reconstitute load bearing tissue such as articulating cartilage, which often cannot replenish themselves or gradually fail to do so in old age. To rectify this, much research has focused on developing hydrogels either as replacement for lost tissue or to serve as a cellular matrix encouraging the production of native tissue. However, hydrogels are nat...

  3. Polyglycerol Based Hydrogels for the Immobilization of Catalytically Active Enzymes and as Scaffolds for Cells

    OpenAIRE

    Dey, Pradip

    2015-01-01

    Im Rahmen dieser Doktorarbeit wurden Hydrogele basierend auf dendritischem Polyglycerol (dPG) entwickelt, welche unter Verwendung verschiedener Vernetzungsreaktionen, wie z. B. durch Amidverknüpfung oder durch ringspannungsvermittelte Azid-Alkin Cycloaddition (strain promoted azide alkyne cycloaddition, SPAAC), hergestellt wurden. Das Anwendungsspektrum dieser Hydrogele reicht von der Entwicklung enzymbasierter Biosensoren bis hin zu Trägermaterialien für Knorpelzellen. Enzymbasierte Bios...

  4. Injectable hydrogel as stem cell scaffolds from the thermosensitive terpolymer of NIPAAm/AAc/HEMAPCL

    Directory of Open Access Journals (Sweden)

    Lian S

    2012-09-01

    Full Text Available Sheng Lian,1Yan Xiao,1 Qingqing Bian,1Yu Xia,2 Changfa Guo,2 Shenguo Wang,2 Meidong Lang11Shanghai Key Laboratory of Advanced Polymeric Materials, Key Laboratory for Ultrafine Materials of Ministry of Education, School of Materials Science and Engineering, East China University of Science and Technology, Shanghai, People's Republic of China; 2Department of Cardiac Surgery, Zhongshan Hospital, Fudan University and Shanghai Institute of Cardiovascular Diseases, Shanghai, People's Republic of ChinaAbstract: A series of biodegradable thermosensitive copolymers was synthesized by free radical polymerization with N-isopropylacrylamide (NIPAAm, acrylic acid (AAc and macromer 2-hydroxylethyl methacrylate-poly(ε-caprolactone (HEMAPCL. The structure and composition of the obtained terpolymers were confirmed by proton nuclear magnetic resonance spectroscopy, while their molecular weight was measured using gel permeation chromatography. The copolymers were dissolved in phosphate-buffered saline (PBS solution (pH = 7.4 with different concentrations to prepare hydrogels. The lower critical solution temperature (LCST, cloud point, and rheological property of the hydrogels were determined by differential scanning calorimetry, ultraviolet-visible spectrometry, and rotational rheometry, respectively. It was found that LCST of the hydrogel increased significantly with the increasing NIPAAm content, and hydrogel with higher AAc/HEMAPCL ratio exhibited better storage modulus, water content, and injectability. The hydrogels were formed by maintaining the copolymer solution at 37°C. The degradation experiment on the formed hydrogels was conducted in PBS solution for 2 weeks and demonstrated a less than 20% weight loss. Scanning electron microscopy was also used to study the morphology of the hydrogel. The copolymer with NIPAAm/AAc/HEMAPCL ratio of 88:9.6:2.4 was bioconjugated with type I collagen for the purpose of biocompatibility enhancement. In-vitro cytotoxicity

  5. Elastic hydrogel as a sensor for detection of mechanical stress generated by single cells grown in three-dimensional environment.

    Science.gov (United States)

    Huang, Jianyong; Wang, Liangli; Xiong, Chunyang; Yuan, Fan

    2016-08-01

    Cell volume growth occurs in all living tissues. The growth exerts mechanical stresses on surrounding tissues that may alter tissue microenvironment, and have significant implications in health and diseases. However, the level of growth stress generated by single cells in three-dimensional (3D) environment remains to be determined. To this end, we developed a growth force microscopy technique to determine 3D distribution of the stress. The technique was based on encapsulation of cells in elastic hydrogels, and involved 3D particle tracking and mechanical analysis of gel deformation. Data from the study demonstrated that the growth stress was dynamic, and the stress distribution at the gel-cell interface was correlated inversely to the mean surface curvature or the distance to the geometric center of the cell. The stress averaged over the cell surface increased with increasing gel stiffness, suggesting that cells could alter growth stress in response to stiffness change in microenvironment. These findings suggested that the elastic hydrogel-based microscopy technique had a potential to provide new insights into mechanisms of mechanical interactions between cell and its microenvironment. PMID:27182812

  6. 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.

  7. Band gap control using electric field of photonic gel cells fabricated with block copolymer and hydrogel.

    Science.gov (United States)

    Lee, Sung Nam; Baek, Young Bin; Shin, Dong Myung

    2014-08-01

    Optical and electrical characteristics of the devices using photonic gel film and hydrogel electrolyte were studied. Poly(styrene-b-2-vinylpyridine) (PS-b-P2VP) lamellar film with alternating hydrophobic block and hydrophilic polyelectrolyte block polymers (52 kg/mol-b-57 kg/mol) were prepared for the photonic gel. Poly(isobutylene-co-maleic acid) sodium salts were prepared for the hydrogel. This hydrogel fiber is common water swelling material and it owned ions for a device has conductivity. Photonic gel and hydrogel was spin coating onto Indium-tin-oxide (ITO) glass for make electric fields. The reflectance maximum wavelength of photonic crystal device shifted from 538 nm and reached to 557 nm, 585 nm and 604 nm during 30 min voltage applying time. The bandwidth variation was very limited. Loss of electrolyte was much less with hydrogel compared to the pure water. We can control color of hydrogel used photonic device by electric field with reasonable time range under moderate electric field by applying 2 V between two facing electrodes. PMID:25936055

  8. Muscle Tissue Engineering Using Gingival Mesenchymal Stem Cells Encapsulated in Alginate Hydrogels Containing Multiple Growth Factors.

    Science.gov (United States)

    Ansari, Sahar; Chen, Chider; Xu, Xingtian; Annabi, Nasim; Zadeh, Homayoun H; Wu, Benjamin M; Khademhosseini, Ali; Shi, Songtao; Moshaverinia, Alireza

    2016-06-01

    Repair and regeneration of muscle tissue following traumatic injuries or muscle diseases often presents a challenging clinical situation. If a significant amount of tissue is lost the native regenerative potential of skeletal muscle will not be able to grow to fill the defect site completely. Dental-derived mesenchymal stem cells (MSCs) in combination with appropriate scaffold material, present an advantageous alternative therapeutic option for muscle tissue engineering in comparison to current treatment modalities available. To date, there has been no report on application of gingival mesenchymal stem cells (GMSCs) in three-dimensional scaffolds for muscle tissue engineering. The objectives of the current study were to develop an injectable 3D RGD-coupled alginate scaffold with multiple growth factor delivery capacity for encapsulating GMSCs, and to evaluate the capacity of encapsulated GMSCs to differentiate into myogenic tissue in vitro and in vivo where encapsulated GMSCs were transplanted subcutaneously into immunocompromised mice. The results demonstrate that after 4 weeks of differentiation in vitro, GMSCs as well as the positive control human bone marrow mesenchymal stem cells (hBMMSCs) exhibited muscle cell-like morphology with high levels of mRNA expression for gene markers related to muscle regeneration (MyoD, Myf5, and MyoG) via qPCR measurement. Our quantitative PCR analyzes revealed that the stiffness of the RGD-coupled alginate regulates the myogenic differentiation of encapsulated GMSCs. Histological and immunohistochemical/fluorescence staining for protein markers specific for myogenic tissue confirmed muscle regeneration in subcutaneous transplantation in our in vivo animal model. GMSCs showed significantly greater capacity for myogenic regeneration in comparison to hBMMSCs (p < 0.05). Altogether, our findings confirmed that GMSCs encapsulated in RGD-modified alginate hydrogel with multiple growth factor delivery capacity is a promising

  9. Polyglycerol dendrimers immobilized on radiation grafted poly-HEMA hydrogels: Surface chemistry characterization and cell adhesion

    International Nuclear Information System (INIS)

    Radiation induced grafting of poly(2-hydroxyethylmethacrylate) (PHEMA) on low density polyethylene (LDPE) films and subsequent immobilization of poly(glycerol) dendrimer (PGLD) has been performed with the aim to improve cell adhesion and proliferation on the surface of the polymer, in order to enhance their properties for bone tissue engineering scaffolding applications. Radiation grafting of PHEMA onto LDPE was promoted by γ-ray radiation. The covalent immobilization of PGLD on LDPE-g-PHEMA surface was performed by using a dicyclohexyl carbodiimide (DCC)/N,N-dimethylaminopyridine (DMAP) method. The occurrence of grafting polymerization of PHEMA and further immobilization of PGLD was quantitatively confirmed by photoelectron spectroscopy (XPS) and fluorescence, respectively. The LDPE-g-PHEMA surface topography after PGLD coupling was studied by atomic force microscopy (AFM). The hydrophilicity of the LDPE-g-PHEMA film was remarkably improved compared to that of the ungrafted LDPE. The core level XPS ESCA spectrum of PHEMA-grafted LDPE showed two strong peaks at 286.6 eV (from hydroxyl groups and ester groups) and 289.1 eV (from ester groups) due to PHEMA brushes grafted onto LDPE surfaces. The results from the cell adhesion studies show that MCT3-E1 cells tended to spread more slowly on the LDPE-g-PHEMA than on the LDPE-g-PHEMA-i-PGLD. - Highlights: • Radiation-grafted PHEMA hydrogels have been obtained by simultaneous gamma-irradiation of LDPE and HEMA monomer. • PGLD dendrimer was immobilized onto PHEMA for application in tissue engineering. • The microstructural characterization of LDPE-g-PHEMA-i-PGLD by RMN, XPS, AFM and MALDI-TOF are made. • Measurements of water uptake and contact angle of LDPE-g-PHEMA are compared to those of LDPE-g-PHEMA-i-PGLD. • The MC3T-E1 osteoblast cell adhesion and growth on LDPE-g-PHEMA-i-PGLD were studied

  10. Seed coat mucilage cells of Arabidopsis thaliana as a model for plant cell wall research.

    Science.gov (United States)

    Arsovski, Andrej A; Haughn, George W; Western, Tamara L

    2010-07-01

    Plant cells are encased within a complex polysaccharide wall that strengthens the cell and has key roles in all aspects of plant cell growth, differentiation, and interaction with the environment. This dynamic structure is under continual modification during plant development, and its synthesis and modification require the activity of a myriad of enzymes. The mucilage secretory cells (MSCs) of the Arabidopsis thaliana seed coat provide a model for the discovery of novel genes involved in the synthesis, secretion and modification of cell wall components, particularly pectin. These cells synthesize copious amounts of pectinaceous mucilage during development and, upon hydration of the desiccated seed, the mucilage rapidly swells, bursts from the MSCs and surrounds the seed in a gelatinous capsule. Several genes affecting MSC differentiation, pectin synthesis, and mucilage release have been identified and additional genes involved in these and related processes including pectin secretion and the mechanical alteration of cell walls await to be discovered. PMID:20505351

  11. A Hyaluronan-Based Injectable Hydrogel Improves the Survival and Integration of Stem Cell Progeny following Transplantation

    Directory of Open Access Journals (Sweden)

    Brian G. Ballios

    2015-06-01

    Full Text Available The utility of stem cells and their progeny in adult transplantation models has been limited by poor survival and integration. We designed an injectable and bioresorbable hydrogel blend of hyaluronan and methylcellulose (HAMC and tested it with two cell types in two animal models, thereby gaining an understanding of its general applicability for enhanced cell distribution, survival, integration, and functional repair relative to conventional cell delivery in saline. HAMC improves cell survival and integration of retinal stem cell (RSC-derived rods in the retina. The pro-survival mechanism of HAMC is ascribed to the interaction of the CD44 receptor with HA. Transient disruption of the retinal outer limiting membrane, combined with HAMC delivery, results in significantly improved rod survival and visual function. HAMC also improves the distribution, viability, and functional repair of neural stem and progenitor cells (NSCs. The HAMC delivery system improves cell transplantation efficacy in two CNS models, suggesting broad applicability.

  12. Microscale characterization of the viscoelastic properties of hydrogel biomaterials using dual-mode ultrasound elastography.

    Science.gov (United States)

    Hong, Xiaowei; Stegemann, Jan P; Deng, Cheri X

    2016-05-01

    Characterization of the microscale mechanical properties of biomaterials is a key challenge in the field of mechanobiology. Dual-mode ultrasound elastography (DUE) uses high frequency focused ultrasound to induce compression in a sample, combined with interleaved ultrasound imaging to measure the resulting deformation. This technique can be used to non-invasively perform creep testing on hydrogel biomaterials to characterize their viscoelastic properties. DUE was applied to a range of hydrogel constructs consisting of either hydroxyapatite (HA)-doped agarose, HA-collagen, HA-fibrin, or preosteoblast-seeded collagen constructs. DUE provided spatial and temporal mapping of local and bulk displacements and strains at high resolution. Hydrogel materials exhibited characteristic creep behavior, and the maximum strain and residual strain were both material- and concentration-dependent. Burger's viscoelastic model was used to extract characteristic parameters describing material behavior. Increased protein concentration resulted in greater stiffness and viscosity, but did not affect the viscoelastic time constant of acellular constructs. Collagen constructs exhibited significantly higher modulus and viscosity than fibrin constructs. Cell-seeded collagen constructs became stiffer with altered mechanical behavior as they developed over time. Importantly, DUE also provides insight into the spatial variation of viscoelastic properties at sub-millimeter resolution, allowing interrogation of the interior of constructs. DUE presents a novel technique for non-invasively characterizing hydrogel materials at the microscale, and therefore may have unique utility in the study of mechanobiology and the characterization of hydrogel biomaterials. PMID:26928595

  13. Three-dimensional printing of stem cell-laden hydrogels submerged in a hydrophobic high-density fluid

    International Nuclear Information System (INIS)

    Over the last decade, bioprinting technologies have begun providing important tissue engineering strategies for regenerative medicine and organ transplantation. The major drawback of past approaches has been poor or inadequate material-printing device and substrate combinations, as well as the relatively small size of the printed construct. Here, we hypothesise that cell-laden hydrogels can be printed when submerged in perfluorotributylamine (C12F27N), a hydrophobic high-density fluid, and that these cells placed within three-dimensional constructs remain viable allowing for cell proliferation and production of extracellular matrix. Human mesenchymal stem cells and MG-63 cells were encapsulated into agarose hydrogels, and subsequently printed in high aspect ratio in three dimensional structures that were supported in high density fluorocarbon. Three-dimensional structures with various shapes and sizes were manufactured and remained stable for more than six months. Live/dead and DAPI stainings showed viable cells 24 h after the printing process, as well as after 21 days in culture. Histological and immunohistochemical analyses after 14 and 21 days revealed viable cells with marked matrix production and signs of proliferation. The compressive strength values of the printed gels consequently increased during the two weeks in culture, revealing encouraging results for future applications in regenerative medicine. (paper)

  14. Novel three-dimensional cocoon-like hydrogels for soft tissue regeneration

    International Nuclear Information System (INIS)

    Large three-dimensional hydrogels (> 150 cm3) of bacterial cellulose (BC) were synthesized by using Gluconacetobacter hansenii ATCC 23769 under controlled agitated culture conditions. The macroscopic cocoon-like structures are gelatinous and translucent and may find applications in several areas, particularly in tissue and organ engineering. Internal microstructure was investigated by scanning electron microscopy (SEM) and field emission scanning electron microscopy (FESEM), which revealed that the cocoons are composed of cellulosic nanofibres randomly and three-dimensionally dispersed. The macroscopic bodies are delimited by a dense semi-permeable membrane with thickness between 0.2 and 2 mm, also composed of cellulosic nanofibres. Endothelial cells were seeded on the hydrogels and incubated for 7 days. HUVECs grew and migrated into the inner part of the structure. The three-dimensional BC hydrogel structures can be directly implanted in tissue deficient regions as scaffolds containing the appropriate cultured cells.

  15. Novel three-dimensional cocoon-like hydrogels for soft tissue regeneration

    Energy Technology Data Exchange (ETDEWEB)

    Recouvreux, Derce O.S. [Integrated Technologies Laboratory, Chemical and Food Engineering Department, Federal University of Santa Catarina, Florianopolis-SC (Brazil); Rambo, Carlos R., E-mail: rambo@intelab.ufsc.br [Integrated Technologies Laboratory, Chemical and Food Engineering Department, Federal University of Santa Catarina, Florianopolis-SC (Brazil); Berti, Fernanda V.; Carminatti, Claudimir A. [Integrated Technologies Laboratory, Chemical and Food Engineering Department, Federal University of Santa Catarina, Florianopolis-SC (Brazil); Antonio, Regina V. [Biochemistry and Molecular Biology of Microorganisms Laboratory, Biochemistry Department, Federal University of Santa Catarina, Florianopolis-SC (Brazil); Porto, Luismar M. [Integrated Technologies Laboratory, Chemical and Food Engineering Department, Federal University of Santa Catarina, Florianopolis-SC (Brazil); Biomedical Engineering Centre, Harvard-MIT Health Sciences and Technology Division, Cambridge-MA (United States)

    2011-03-12

    Large three-dimensional hydrogels (> 150 cm{sup 3}) of bacterial cellulose (BC) were synthesized by using Gluconacetobacter hansenii ATCC 23769 under controlled agitated culture conditions. The macroscopic cocoon-like structures are gelatinous and translucent and may find applications in several areas, particularly in tissue and organ engineering. Internal microstructure was investigated by scanning electron microscopy (SEM) and field emission scanning electron microscopy (FESEM), which revealed that the cocoons are composed of cellulosic nanofibres randomly and three-dimensionally dispersed. The macroscopic bodies are delimited by a dense semi-permeable membrane with thickness between 0.2 and 2 mm, also composed of cellulosic nanofibres. Endothelial cells were seeded on the hydrogels and incubated for 7 days. HUVECs grew and migrated into the inner part of the structure. The three-dimensional BC hydrogel structures can be directly implanted in tissue deficient regions as scaffolds containing the appropriate cultured cells.

  16. Pumpkin seed extract: Cell growth inhibition of hyperplastic and cancer cells, independent of steroid hormone receptors.

    Science.gov (United States)

    Medjakovic, Svjetlana; Hobiger, Stefanie; Ardjomand-Woelkart, Karin; Bucar, Franz; Jungbauer, Alois

    2016-04-01

    Pumpkin seeds have been known in folk medicine as remedy for kidney, bladder and prostate disorders since centuries. Nevertheless, pumpkin research provides insufficient data to back up traditional beliefs of ethnomedical practice. The bioactivity of a hydro-ethanolic extract of pumpkin seeds from the Styrian pumpkin, Cucurbita pepo L. subsp. pepo var. styriaca, was investigated. As pumpkin seed extracts are standardized to cucurbitin, this compound was also tested. Transactivational activity was evaluated for human androgen receptor, estrogen receptor and progesterone receptor with in vitro yeast assays. Cell viability tests with prostate cancer cells, breast cancer cells, colorectal adenocarcinoma cells and a hyperplastic cell line from benign prostate hyperplasia tissue were performed. As model for non-hyperplastic cells, effects on cell viability were tested with a human dermal fibroblast cell line (HDF-5). No transactivational activity was found for human androgen receptor, estrogen receptor and progesterone receptor, for both, extract and cucurbitin. A cell growth inhibition of ~40-50% was observed for all cell lines, with the exception of HDF-5, which showed with ~20% much lower cell growth inhibition. Given the receptor status of some cell lines, a steroid-hormone receptor independent growth inhibiting effect can be assumed. The cell growth inhibition for fast growing cells together with the cell growth inhibition of prostate-, breast- and colon cancer cells corroborates the ethnomedical use of pumpkin seeds for a treatment of benign prostate hyperplasia. Moreover, due to the lack of androgenic activity, pumpkin seed applications can be regarded as safe for the prostate. PMID:26976217

  17. Desiccation sensitivity and cell cycle aspects in seeds of Inga vera subsp. affinis

    NARCIS (Netherlands)

    Faria, J.M.R.; Lammeren, van A.A.M.; Hilhorst, H.W.M.

    2004-01-01

    The desiccation sensitivity of seeds of Inga vera Willd. subsp. affinis, a recalcitrant-seeded tree from Brazil, was analysed, focusing on water relations and cell-cycle aspects, including DNA content and the microtubular cytoskeleton. Seeds were collected at four developmental stages, dried to diff

  18. Hydrogel based occlusion systems

    OpenAIRE

    Stam, F.A.; Jackson, N.; Dubruel, P.; Adesanya, K.; Embrechts, A.; Mendes, E.; Neves, H.P.; Herijgers, P.; Verbrugghe, Y.; Shacham, Y; Engel, L.; Krylov, V.

    2013-01-01

    A hydrogel based occlusion system, a method for occluding vessels, appendages or aneurysms, and a method for hydrogel synthesis are disclosed. The hydrogel based occlusion system includes a hydrogel having a shrunken and a swollen state and a delivery tool configured to deliver the hydrogel to a target occlusion location. The hydrogel is configured to permanently occlude the target occlusion location in the swollen state. The hydrogel may be an electro-activated hydrogel (EAH) which could be ...

  19. Stiffness-Independent Highly Efficient On-Chip Extraction of Cell-Laden Hydrogel Microcapsules from Oil Emulsion into Aqueous Solution by Dielectrophoresis.

    Science.gov (United States)

    Huang, Haishui; Sun, Mingrui; Heisler-Taylor, Tyler; Kiourti, Asimina; Volakis, John; Lafyatis, Gregory; He, Xiaoming

    2015-10-28

    A dielectrophoresis (DEP)-based method achieves highly efficient on-chip extraction of cell-laden microcapsules of any stiffness from oil into aqueous solution. The hydrogel microcapsules can be extracted into the aqueous solution by DEP and interfacial tension forces with no trapped oil, while the encapsulated cells are free from electrical damage due to the Faraday cage effect. PMID:26297051

  20. A feeder-free, human plasma-derived hydrogel for maintenance of a human embryonic stem cell phenotype in vitro

    Directory of Open Access Journals (Sweden)

    Lewis Fiona C

    2012-08-01

    Full Text Available Abstract Background Human embryonic stem cells (hESCs represent a tremendous resource for cell therapies and the study of human development; however to maintain their undifferentiated state in vitro they routinely require the use of mouse embryonic fibroblast (MEF feeder-layers and exogenous protein media supplementation. Results These well established requirements can be overcome and in this study, it will be demonstrated that phenotypic stability of hESCs can be maintained using a novel, human plasma protein-based hydrogel as an extracellular culture matrix without the use of feeder cell co-culture. hESCs were resuspended in human platelet poor plasma (PPP, which was gelled by the addition of calcium containing DMEM-based hESC culture medium. Phenotypic and genomic expression of the pluripotency markers OCT4, NANOG and SOX2 were measured using immunohistochemistry and qRT-PCR respectively. Typical hESC morphology was demonstrated throughout in vitro culture and both viability and phenotypic stability were maintained throughout extended culture, up to 25 passages. Conclusions PPP-derived hydrogel has demonstrated to be an efficacious alternative to MEF co-culture with its hydrophilicity allowing for this substrate to be delivered via minimally invasive procedures in a liquid phase with polymerization ensuing in situ. Together this provides a novel technique for the study of this unique group of stem cells in either 2D or 3D both in vitro and in vivo.

  1. Functionalization, preparation and use of cell-laden gelatin methacryloyl-based hydrogels as modular tissue culture platforms.

    Science.gov (United States)

    Loessner, Daniela; Meinert, Christoph; Kaemmerer, Elke; Martine, Laure C; Yue, Kan; Levett, Peter A; Klein, Travis J; Melchels, Ferry P W; Khademhosseini, Ali; Hutmacher, Dietmar W

    2016-04-01

    Progress in advancing a system-level understanding of the complexity of human tissue development and regeneration is hampered by a lack of biological model systems that recapitulate key aspects of these processes in a physiological context. Hence, growing demand by cell biologists for organ-specific extracellular mimics has led to the development of a plethora of 3D cell culture assays based on natural and synthetic matrices. We developed a physiological microenvironment of semisynthetic origin, called gelatin methacryloyl (GelMA)-based hydrogels, which combine the biocompatibility of natural matrices with the reproducibility, stability and modularity of synthetic biomaterials. We describe here a step-by-step protocol for the preparation of the GelMA polymer, which takes 1-2 weeks to complete, and which can be used to prepare hydrogel-based 3D cell culture models for cancer and stem cell research, as well as for tissue engineering applications. We also describe quality control and validation procedures, including how to assess the degree of GelMA functionalization and mechanical properties, to ensure reproducibility in experimental and animal studies. PMID:26985572

  2. Treating spinal cord injury in rats with a combination of human fetal neural stem cells and hydrogels modified with serotonin

    Czech Academy of Sciences Publication Activity Database

    Růžička, Jiří; Romanyuk, Nataliya; Hejčl, Aleš; Vetrík, Miroslav; Hrubý, Martin; Cocks, G.; Cihlář, J.; Přádný, Martin; Price, J.; Syková, Eva; Jendelová, Pavla

    2013-01-01

    Roč. 73, č. 1 (2013), s. 102-115. ISSN 0065-1400 R&D Projects: GA ČR GAP108/10/1560; GA ČR(CZ) GPP304/11/P633; GA ČR GA13-00939S; GA AV ČR IAA500390902 Grant ostatní: GA MŠk(CZ) GAUK521712 Institutional support: RVO:68378041 ; RVO:61389013 Keywords : spinal cord hemisection * SPC-01 neural stem cells * hydrogel Subject RIV: FH - Neurology; CD - Macromolecular Chemistry (UMCH-V) Impact factor: 2.244, year: 2013

  3. Hydrogels for Engineering of Perfusable Vascular Networks

    Directory of Open Access Journals (Sweden)

    Juan Liu

    2015-07-01

    Full Text Available Hydrogels are commonly used biomaterials for tissue engineering. With their high-water content, good biocompatibility and biodegradability they resemble the natural extracellular environment and have been widely used as scaffolds for 3D cell culture and studies of cell biology. The possible size of such hydrogel constructs with embedded cells is limited by the cellular demand for oxygen and nutrients. For the fabrication of large and complex tissue constructs, vascular structures become necessary within the hydrogels to supply the encapsulated cells. In this review, we discuss the types of hydrogels that are currently used for the fabrication of constructs with embedded vascular networks, the key properties of hydrogels needed for this purpose and current techniques to engineer perfusable vascular structures into these hydrogels. We then discuss directions for future research aimed at engineering of vascularized tissue for implantation.

  4. The influence of the scaffold design on the distribution of adhering cells after perfusion cell seeding

    NARCIS (Netherlands)

    Melchels, Ferry P.W.; Tonnarelli, Beatrice; Olivares, Andy L.; Martin, Ivan; Lacroix, Damien; Feijen, Jan; Wendt, David J.; Grijpma, Dirk W.

    2011-01-01

    In natural tissues, the extracellular matrix composition, cell density and physiological properties are often non-homogeneous. Here we describe a model system, in which the distribution of cells throughout tissue engineering scaffolds after perfusion seeding can be influenced by the pore architectur

  5. Seed coat mucilage cells of Arabidopsis thaliana as a model for plant cell wall research

    OpenAIRE

    Arsovski, Andrej A; Haughn, George W; Western, Tamara L.

    2010-01-01

    Plant cells are encased within a complex polysaccharide wall that strengthens the cell and has key roles in all aspects of plant cell growth, differentiation and interaction with the environment. This dynamic structure is under continual modification during plant development, and its synthesis and modification require the activity of a myriad of enzymes. The mucilage secretory cells (MSCs) of the Arabidopsis thaliana seed coat provide a model for the discovery of novel genes involved in the s...

  6. Fibronectin- and collagen-mimetic ligands regulate bone marrow stromal cell chondrogenesis in three-dimensional hydrogels

    Directory of Open Access Journals (Sweden)

    JT Connelly

    2011-09-01

    Full Text Available Modification of tissue engineering scaffolds with bioactive molecules is a potential strategy for modulating cell behavior and guiding tissue regeneration. While adhesion to RGD peptides has been shown to inhibit in vitro chondrogenesis, the effects of extracellular matrix (ECM-mimetic ligands with complex secondary and tertiary structures are unknown. This study aimed to determine whether collagen- and fibronectin-mimetic ligands would retain biologic functionality in three-dimensional (3D hydrogels, whether different ECM-mimetic ligands differentially influence in vitro chondrogenesis, and if effects of ligands on differentiation depend on soluble biochemical stimuli. A linear RGD peptide, a recombinant fibronectin fragment containing the seven to ten Type III repeats (FnIII7-10 and a triple helical, collagen mimetic peptide with the GFOGER motif were covalently coupled to agarose gels using the sulfo-SANPAH crosslinker, and bone marrow stromal cells (BMSCs were cultured within the 3D hydrogels. The ligands retained biologic functionality within the agarose gels and promoted density-dependent BMSC spreading. Interactions with all adhesive ligands inhibited stimulation by chondrogenic factors of collagen Type II and aggrecan mRNA levels and deposition of sulfated glycosaminoglycans. In medium containing fetal bovine serum, interactions with the GFOGER peptide enhanced mRNA expression of the osteogenic gene osteocalcin whereas FnIII7-10 inhibited osteocalcin expression. In conclusion, modification of agarose hydrogels with ECM-mimetic ligands can influence the differentiation of BMSCs in a manner that depends strongly on the presence and nature of soluble biochemical stimuli.

  7. Direct hydrogel encapsulation of pluripotent stem cells enables ontomimetic differentiation and growth of engineered human heart tissues.

    Science.gov (United States)

    Kerscher, Petra; Turnbull, Irene C; Hodge, Alexander J; Kim, Joonyul; Seliktar, Dror; Easley, Christopher J; Costa, Kevin D; Lipke, Elizabeth A

    2016-03-01

    Human engineered heart tissues have potential to revolutionize cardiac development research, drug-testing, and treatment of heart disease; however, implementation is limited by the need to use pre-differentiated cardiomyocytes (CMs). Here we show that by providing a 3D poly(ethylene glycol)-fibrinogen hydrogel microenvironment, we can directly differentiate human pluripotent stem cells (hPSCs) into contracting heart tissues. Our straight-forward, ontomimetic approach, imitating the process of development, requires only a single cell-handling step, provides reproducible results for a range of tested geometries and size scales, and overcomes inherent limitations in cell maintenance and maturation, while achieving high yields of CMs with developmentally appropriate temporal changes in gene expression. We demonstrate that hPSCs encapsulated within this biomimetic 3D hydrogel microenvironment develop into functional cardiac tissues composed of self-aligned CMs with evidence of ultrastructural maturation, mimicking heart development, and enabling investigation of disease mechanisms and screening of compounds on developing human heart tissue. PMID:26826618

  8. Human dental pulp stem cell is a promising autologous seed cell for bone tissue engineering

    Institute of Scientific and Technical Information of China (English)

    LI Jing-hui; LIU Da-yong; ZHANG Fang-ming; WANG Fan; ZHANG Wen-kui; ZHANG Zhen-ting

    2011-01-01

    Background The seed cell is a core problem in bone tissue engineering research.Recent research indicates that human dental pulp stem cells (hDPSCs) can differentiate into osteoblasts in vitro,which suggests that they may become a new kind of seed cells for bone tissue engineering.The aim of this study was to evaluate the osteogenic differentiation of hDPSCs in vitro and bone-like tissue formation when transplanted with three-dimensional gelatin scaffolds in vivo,and hDPSCs may become appropriate seed cells for bone tissue engineering.Methods We have utilized enzymatic digestion to obtain hDPSCs from dental pulp tissue extracted during orthodontic treatment.After culturing and expansion to three passages,the cells were seeded in 6-well plates or on three-dimensional gelatin scaffolds and cultured in osteogenic medium.After 14 days in culture,the three-dimensional gelatin scaffolds were implanted subcutaneously in nude mice for 4 weeks.In 6-well plate culture,osteogenesis was assessed by alkaline phosphatase staining,Von Kossa staining,and reverse transcription-polymerase chain reaction (RT-PCR) analysis of the osteogenesis-specific genes type I collagen (COL l),bone sialoprotein (BSP),osteocalcin (OCN),RUNX2,and osterix (OSX).In three-dimensional gelatin scaffold culture,X-rays,hematoxylin/eosin staining,and immunohistochemical staining were used to examine bone formation.Results In vitro studies revealed that hDPSCs do possess osteogenic differentiation potential.In vivo studies revealed that hDPSCs seeded on gelatin scaffolds can form bone structures in heterotopic sites of nude mice.Conclusions These findings suggested that hDPSCs may be valuable as seed cells for bone tissue engineering.As a special stem cell source,hDPSCs may blaze a new path for bone tissue engineering.

  9. F2 excimer laser (157 nm) radiation modification and surface ablation of PHEMA hydrogels and the effects on bioactivity: Surface attachment and proliferation of human corneal epithelial cells

    International Nuclear Information System (INIS)

    Physical and chemical changes at the surface of poly(2-hydroxyethyl methacrylate) (PHEMA) hydrogels modified by ablation with an F2 excimer laser were investigated experimentally. An important observation was that only the outer exposed surface layers of the hydrogel were affected by the exposure to 157 nm radiation. The effect of the surface changes on the tendency of cells to adhere to the PHEMA was also investigated. A 0.5 cm2 area of the hydrogel surfaces was exposed to laser irradiation at 157 nm to fluences of 0.8 and 4 J cm-2. The changes in surface topography were analysed by light microscopy and atomic force microscopy, while the surface chemistry was characterized by attenuated total reflection infrared and X-ray photoelectron spectroscopies. Cell-interfacial interactions were examined based on the proliferation of human corneal limbal epithelial (HLE) cells cultured on the laser-modified hydrogels, and on the unexposed hydrogels and tissue culture plastic for comparison. It was observed that the surface topography of laser-exposed hydrogels showed rippled patterns with a surface roughness increasing at the higher exposure dose. The changes in surface chemistry were affected not only by an indirect effect of hydrogen and hydroxyl radicals, formed by water photolysis, on the PHEMA, but also by the direct action of laser radiation on PHEMA if the surface layers of the gel become depleted of water. The laser treatment led to a change in the surface characteristics, with a lower concentration of ester side-chains and the formation of new oxygenated species at the surface. The surface also became more hydrophobic. Most importantly, the surface chemistry and the newly created surface topographical features were able to improve the attachment, spreading and growth of HLE cells.

  10. 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

  11. Programmed cell death during development of cowpea (Vigna unguiculata (L.) Walp.) seed coat.

    Science.gov (United States)

    Lima, Nathália Bastos; Trindade, Fernanda Gomes; da Cunha, Maura; Oliveira, Antônia Elenir Amâncio; Topping, Jennifer; Lindsey, Keith; Fernandes, Kátia Valevski Sales

    2015-04-01

    The seed coat develops primarily from maternal tissues and comprises multiple cell layers at maturity, providing a metabolically dynamic interface between the developing embryo and the environment during embryogenesis, dormancy and germination of seeds. Seed coat development involves dramatic cellular changes, and the aim of this research was to investigate the role of programmed cell death (PCD) events during the development of seed coats of cowpea [Vigna unguiculata (L.) Walp.]. We demonstrate that cells of the developing cowpea seed coats undergo a programme of autolytic cell death, detected as cellular morphological changes in nuclei, mitochondria, chloroplasts and vacuoles, DNA fragmentation and oligonucleosome accumulation in the cytoplasm, and loss of membrane viability. We show for the first time that classes 6 and 8 caspase-like enzymes are active during seed coat development, and that these activities may be compartmentalized by translocation between vacuoles and cytoplasm during PCD events. PMID:25142352

  12. Evaluation of hela cell lineage response to β radiation from Holmium-166 embedded in ceramic seeds

    Directory of Open Access Journals (Sweden)

    Eduardo Sarmento Valente

    2011-10-01

    Full Text Available This work studied the effects of β radiation of Ho-166 embedded in ceramic seeds on HeLa cells. Methodology consisted in the production of ceramic seeds with holmium-165 by sol-gel route. Chemical and physical characterizations of the seeds were performed. Subsequently, nuclear characterization was performed by gamma spectrometry. Experimental and theoretical activities were defined and initial dose rate were evaluated by MIRD (Medical Internal Radiation Dose Committee methodology. The seeds were placed in confluent culture flasks and remained for six radionuclide half-lives. Biological results were represented by a clean 6 mm diameter area around the seed where the tumour cells were killed. The initial dose rate was 15.5 Gy. h-1. The maximum absorbed dose was 591.3 Gy. The features of the Ho-166 seeds suggested that such ceramic seeds were suitable for high dose rate brachytherapy.

  13. Comparison of articular cartilage repair with different hydrogel-human umbilical cord blood-derived mesenchymal stem cell composites in a rat model

    OpenAIRE

    Chung, Jun Young; Song, Minjung; Ha, Chul-Won; Kim, Jin-A; Lee, Choong-Hee; Park, Yong-Beom

    2014-01-01

    Introduction The present work was designed to explore the feasibility and efficacy of articular cartilage repair using composites of human umbilical cord blood derived mesenchymal stem cells (hUCB-MSCs) and four different hydrogels in a rat model. Methods Full-thickness articular cartilage defects were created at the trochlear groove of femur in both knees of rats. Composites of hUCB-MSCs and four different hydrogels (group A, 4% hyaluronic acid; group B, 3% alginate:30% pluronic (1:1, v/v); ...

  14. Pulmonary heart valve replacement using stabilized acellular xenogeneic scaffolds; effects of seeding with autologous stem cells

    Directory of Open Access Journals (Sweden)

    Harpa Marius Mihai

    2015-12-01

    Full Text Available Background: We hypothesized that an ideal heart valve replacement would be acellular valve root scaffolds seeded with autologous stem cells. To test this hypothesis, we prepared porcine acellular pulmonary valves, seeded them with autologous adipose derived stem cells (ADSCs and implanted them in sheep and compared them to acellular valves.

  15. Two cationic peroxidases from cell walls of Araucaria araucana seeds.

    Science.gov (United States)

    Riquelme, A; Cardemil, L

    1995-05-01

    We have previously reported the purification and partial characterization of two cationic peroxidases from the cell walls of seeds and seedlings of the South American conifer, Araucaria araucana. In this work, we have studied the amino acid composition and NH2-terminal sequences of both enzymes. We also compare the data obtained from these analyses with those reported for other plant peroxidases. The two peroxidases are similar in their amino acid compositions. Both are particularly rich in glycine, which comprises more than 30% of the amino acid residues. The content of serine is also high, ca 17%. The two enzymes are different in their content of arginine, alanine, valine, phenylalanine and threonine. Both peroxidases have identical NH2-terminal sequences, indicating that the two proteins are genetically related and probably are isoforms of the same kind of peroxidase. The amino acid composition and NH2-terminal sequence analyses showed marked differences from the cationic peroxidases from turnip and horseradish. PMID:7786490

  16. Designed biodegradable hydrogel structures prepared by stereolithography using poly(ethylene glycol)/poly(D,L-lactide)-based resins.

    Science.gov (United States)

    Seck, Tetsu M; Melchels, Ferry P W; Feijen, Jan; Grijpma, Dirk W

    2010-11-20

    Designed three-dimensional biodegradable poly(ethylene glycol)/poly(D,L-lactide) hydrogel structures were prepared for the first time by stereolithography at high resolutions. A photo-polymerisable aqueous resin comprising PDLLA-PEG-PDLLA-based macromer, visible light photo-initiator, dye and inhibitor in DMSO/water was used to build the structures. Porous and non-porous hydrogels with well-defined architectures and good mechanical properties were prepared. Porous hydrogel structures with a gyroid pore network architecture showed narrow pore size distributions, excellent pore interconnectivity and good mechanical properties. The structures showed good cell seeding characteristics, and human mesenchymal stem cells adhered and proliferated well on these materials. PMID:20659509

  17. Synthetic poly(amino acid) hydrogels with incorporated cell-adhesion peptides for tissue engineering

    Czech Academy of Sciences Publication Activity Database

    Studenovská, Hana; Vodička, Petr; Proks, Vladimír; Hlučilová, Jana; Motlík, Jan; Rypáček, František

    2010-01-01

    Roč. 4, č. 6 (2010), s. 454-463. ISSN 1932-6254 R&D Projects: GA AV ČR KJB400500801; GA MŠk 1M0538 Institutional research plan: CEZ:AV0Z40500505; CEZ:AV0Z50450515 Keywords : polyamino acid * hydrogel * porosity Subject RIV: CD - Macromolecular Chemistry Impact factor: 3.534, year: 2010

  18. Microfabrication of a tunable collagen/alginate-chitosan hydrogel membrane for controlling cell-cell interactions.

    Science.gov (United States)

    Song, Yizhe; Zhang, Demeng; Lv, Yan; Guo, Xin; Lou, Ruyun; Wang, Shujun; Wang, Xiuli; Yu, Weiting; Ma, Xiaojun

    2016-11-20

    Indirect cell contact co-culture system is increasingly becoming more attractable owing to their advantages of easy cell separation and desirable outcomes for cell-cell interactions. However, how to precisely control the spatial position of cells within multicellular co-cultures is still experimentally challenging due to the incapability of the conventional methods in vitro. In the present study, a tunable collagen/alginate-chitosan (Col/Alg-Chi) membrane was established, which was capable of controlling intercellular distance between the neighboring cells at a level of micrometer resolution. It was showed that intercellular distance between the hepatocytes and the fibroblasts exerted significant influence on hepatic function in vitro. In particular, maintenance of the functionality of primary hepatocytes requires direct contact between the hepatocytes and their supportive stromal cells, and their effective contact distance is within 30μm. This technical platform would potentially enable investigations of dynamic cell-cell interaction in a multitude of applications including organogenesis, development or even neoplastic transformation. PMID:27561537

  19. Hydrogel based occlusion systems

    NARCIS (Netherlands)

    Stam, F.A.; Jackson, N.; Dubruel, P.; Adesanya, K.; Embrechts, A.; Mendes, E.; Neves, H.P.; Herijgers, P.; Verbrugghe, Y.; Shacham, Y.; Engel, L.; Krylov, V.

    2013-01-01

    A hydrogel based occlusion system, a method for occluding vessels, appendages or aneurysms, and a method for hydrogel synthesis are disclosed. The hydrogel based occlusion system includes a hydrogel having a shrunken and a swollen state and a delivery tool configured to deliver the hydrogel to a tar

  20. Optimization of process parameters for the continuous ethanol production by Kluyveromyces lactis immobilized cells in hydrogel copolymer carrier.

    Science.gov (United States)

    Deriase, S F; Farahat, L M; El-Batal, A I

    2001-01-01

    In the present study the optimized parameters for highest ethanol productivity by Kluyveromyces lactis immobilized cells bioreactor were obtained using the method of Lagrange multipliers. Immobilized growing yeast cells in PVA: HEMA (7%: 10%, w/w) hydrogel copolymer carrier produced by radiation polymerization were used in a packed-bed column reactor for the continuous production of ethanol from lactose at different levels of concentrations (50, 100 and 150) gL(-1). The results indicate that volumetric ethanol productivity is influenced by substrate concentration and dilution rate. The highest value 7.17 gL(-1) h(-1) is obtained at higher lactose concentration (150 gL(-1)) in feed medium and 0.3 h(-1) dilution rate. The same results have been obtained through the application of "LINGO" software for mathematical optimization. PMID:11518393

  1. Electrically conductive gold nanoparticle-chitosan thermosensitive hydrogels for cardiac tissue engineering.

    Science.gov (United States)

    Baei, Payam; Jalili-Firoozinezhad, Sasan; Rajabi-Zeleti, Sareh; Tafazzoli-Shadpour, Mohammad; Baharvand, Hossein; Aghdami, Nasser

    2016-06-01

    Injectable hydrogels that resemble electromechanical properties of the myocardium are crucial for cardiac tissue engineering prospects. We have developed a facile approach that uses chitosan (CS) to generate a thermosensitive conductive hydrogel with a highly porous network of interconnected pores. Gold nanoparticles (GNPs) were evenly dispersed throughout the CS matrix in order to provide electrical cues. The gelation response and electrical conductivity of the hydrogel were controlled by different concentrations of GNPs. The CS-GNP hydrogels were seeded with mesenchymal stem cells (MSCs) and cultivated for up to 14days in the absence of electrical stimulations. CS-GNP scaffolds supported viability, metabolism, migration and proliferation of MSCs along with the development of uniform cellular constructs. Immunohistochemistry for early and mature cardiac markers showed enhanced cardiomyogenic differentiation of MSCs within the CS-GNP compared to the CS matrix alone. The results of this study demonstrate that incorporation of nanoscale electro-conductive GNPs into CS hydrogels enhances the properties of myocardial constructs. These constructs could find utilization for regeneration of other electroactive tissues. PMID:27040204

  2. The Effect of Cumin Seed Extracts against Herpes Simplex Virus Type 1 in Vero Cell Culture

    OpenAIRE

    Mohammad Motamedifar; Narjes Ghafari; Pedram Talezadeh Shirazi

    2010-01-01

    Background: Cumin (Cuminum cyminum L. [family Apiaceae])seed essential oil is reported to have antiseptic activity.Until now the antiviral properties of cumin seed extracts onviruses such as herpes simplex virus-1 (HSV-1) have not beenstudied. The objective of this study was to investigate the invitro effects of aqueous, methanolic and hydroalcoholic extractsof cumin seed on HSV-1 growth in Vero cell line.Methods: Antiviral activity of various concentrations aqueous,hydroalcoholic and methano...

  3. ANTICANCER ACTIVITY OF PONGAMIA GLABRA V. SEED OIL EXTRACT AGAINST SELECTED HUMAN CANCER CELL LINES

    OpenAIRE

    Chinnasamy Arulvasu; Subramanian Vasantha suppriya; Gajendran Babu

    2012-01-01

    Screening of the seed oil extract from Pongamia glabra V. (Fabaceae) has been carried out for antiproliferative activity of cancer cells. The seed oil was extracted with methanol and then persuasive activity was tested on human cancer cell lines MCF-7 and HeLa. The cell growth inhibitory effects of seed oil extract was observed. The cell viability was assessed using trypan blue dye exclusion method and 3-(4, 5- Dimethyl thiazol-2yl)-2, 5-dimethyltetrazolium bromide (MTT) assay. The IC50 value...

  4. Avidity-controlled hydrogels for injectable co-delivery of induced pluripotent stem cell-derived endothelial cells and growth factors.

    Science.gov (United States)

    Mulyasasmita, Widya; Cai, Lei; Dewi, Ruby E; Jha, Arshi; Ullmann, Sabrina D; Luong, Richard H; Huang, Ngan F; Heilshorn, Sarah C

    2014-10-10

    To translate recent advances in induced pluripotent stem cell biology to clinical regenerative medicine therapies, new strategies to control the co-delivery of cells and growth factors are needed. Building on our previous work designing Mixing-Induced Two-Component Hydrogels (MITCHs) from engineered proteins, here we develop protein-polyethylene glycol (PEG) hybrid hydrogels, MITCH-PEG, which form physical gels upon mixing for cell and growth factor co-delivery. MITCH-PEG is a mixture of C7, which is a linear, engineered protein containing seven repeats of the CC43 WW peptide domain (C), and 8-arm star-shaped PEG conjugated with either one or two repeats of a proline-rich peptide to each arm (P1 or P2, respectively). Both 20kDa and 40kDa star-shaped PEG variants were investigated, and all four PEG-peptide variants were able to undergo a sol-gel phase transition when mixed with the linear C7 protein at constant physiological conditions due to noncovalent hetero-dimerization between the C and P domains. Due to the dynamic nature of the C-P physical crosslinks, all four gels were observed to be reversibly shear-thinning and self-healing. The P2 variants exhibited higher storage moduli than the P1 variants, demonstrating the ability to tune the hydrogel bulk properties through a biomimetic peptide-avidity strategy. The 20kDa PEG variants exhibited slower release of encapsulated vascular endothelial growth factor (VEGF), due to a decrease in hydrogel mesh size relative to the 40kDa variants. Human induced pluripotent stem cell-derived endothelial cells (hiPSC-ECs) adopted a well-spread morphology within three-dimensional MITCH-PEG cultures, and MITCH-PEG provided significant protection from cell damage during ejection through a fine-gauge syringe needle. In a mouse hindlimb ischemia model of peripheral arterial disease, MITCH-PEG co-delivery of hiPSC-ECs and VEGF was found to reduce inflammation and promote muscle tissue regeneration compared to a saline control. PMID

  5. The root canal system: A channel through which we can seed cells into grafts

    OpenAIRE

    Cheng, Gu; Li, Zu-bing

    2014-01-01

    Bone tissue engineering is bringing hope to patients with jawbone defects, but this technology works well only for small- to moderate-sized jawbone defects. For large segmental jawbone defects, it is difficult to form the functional vascular networks within the graft due to limited diffusion of nutrition and uneven distribution of seed cells. From the standpoint of bionics, seed cells should be continuously transmitted into the graft to replace the necrotic cells during the entire process of ...

  6. Biomimetic coating of apatite/collagen composite on poly L-lactic acid facilitates cell seeding

    OpenAIRE

    Chen, Y; Mak, AFT; Wang, M; Li, J.

    2005-01-01

    Collagen and apatite were co-precipitated as a composite coating on poly L-lactic acid (PLLA) in an accelerated biomimetic process. The coating formed on PLLA films after 24 hours incubation was characterized. Saos-2 osteoblast-like cells were used to evaluate the cell seeding on this biomimetic composite coating. It was shown that cell seeding on PLLA films with the composite coating was greatly improved. PLLA coated with submicron collagen fibrils and submicron apatite paticulates can facil...

  7. In vivo cell wall loosening by hydroxyl radicals during cress seed germination and elongation growth

    OpenAIRE

    Müller, Kerstin; Linkies, Ada; Vreeburg, Robert A. M.; Fry, Stephen C; Krieger-Liszkay, Anja; Leubner-Metzger, Gerhard

    2009-01-01

    Loosening of cell walls is an important developmental process in key stages of plant life cycles, including seed germination, elongation growth and fruit ripening. Here we report direct in vivo evidence for hydroxyl radical (•OH)-mediated cell wall loosening during plant seed germination and seedling growth. We used electron paramagnetic resonance (EPR)-spectroscopy to show that •OH is generated in the cell wall during radicle elongation and weakening of the endosperm of cress (Lepidium sativ...

  8. Starting to Gel: How Arabidopsis Seed Coat Epidermal Cells Produce Specialized Secondary Cell Walls

    Directory of Open Access Journals (Sweden)

    Cătălin Voiniciuc

    2015-02-01

    Full Text Available For more than a decade, the Arabidopsis seed coat epidermis (SCE has been used as a model system to study the synthesis, secretion and modification of cell wall polysaccharides, particularly pectin. Our detailed re-evaluation of available biochemical data highlights that Arabidopsis seed mucilage is more than just pectin. Typical secondary wall polymers such as xylans and heteromannans are also present in mucilage. Despite their low abundance, these components appear to play essential roles in controlling mucilage properties, and should be further investigated. We also provide a comprehensive community resource by re-assessing the mucilage phenotypes of almost 20 mutants using the same conditions. We conduct an in-depth functional evaluation of all the SCE genes described in the literature and propose a revised model for mucilage production. Further investigation of SCE cells will improve our understanding of plant cell walls.

  9. Porous Hydrogels

    Czech Academy of Sciences Publication Activity Database

    Přádný, Martin; Michálek, Jiří; Širc, Jakub

    New York: Nova Science Publishers, 2009 - (Acosta, J.; Camacho, A.), s. 57-74 ISBN 978-1-60741-401-8 R&D Projects: GA AV ČR 1QS400500558; GA MŠk 1M0538 Institutional research plan: CEZ:AV0Z40500505 Keywords : hydrogels * porous * tissue engineering Subject RIV: CD - Macromolecular Chemistry

  10. Fabrication and development of artificial osteochondral constructs based on cancellous bone/hydrogel hybrid scaffold.

    Science.gov (United States)

    Song, Kedong; Li, Liying; Yan, Xinyu; Zhang, Yu; Li, Ruipeng; Wang, Yiwei; Wang, Ling; Wang, Hong; Liu, Tianqing

    2016-06-01

    Using tissue engineering techniques, an artificial osteochondral construct was successfully fabricated to treat large osteochondral defects. In this study, porcine cancellous bones and chitosan/gelatin hydrogel scaffolds were used as substitutes to mimic bone and cartilage, respectively. The porosity and distribution of pore size in porcine bone was measured and the degradation ratio and swelling ratio for chitosan/gelatin hydrogel scaffolds was also determined in vitro. Surface morphology was analyzed with the scanning electron microscope (SEM). The physicochemical properties and the composition were tested by using an infrared instrument. A double layer composite scaffold was constructed via seeding adipose-derived stem cells (ADSCs) induced to chondrocytes and osteoblasts, followed by inoculation in cancellous bones and hydrogel scaffolds. Cell proliferation was assessed through Dead/Live staining and cellular activity was analyzed with IpWin5 software. Cell growth, adhesion and formation of extracellular matrix in composite scaffolds blank cancellous bones or hydrogel scaffolds were also analyzed. SEM analysis revealed a super porous internal structure of cancellous bone scaffolds and pore size was measured at an average of 410 ± 59 μm while porosity was recorded at 70.6 ± 1.7 %. In the hydrogel scaffold, the average pore size was measured at 117 ± 21 μm and the porosity and swelling rate were recorded at 83.4 ± 0.8 % and 362.0 ± 2.4 %, respectively. Furthermore, the remaining hydrogel weighed 80.76 ± 1.6 % of the original dry weight after hydration in PBS for 6 weeks. In summary, the cancellous bone and hydrogel composite scaffold is a promising biomaterial which shows an essential physical performance and strength with excellent osteochondral tissue interaction in situ. ADSCs are a suitable cell source for osteochondral composite reconstruction. Moreover, the bi-layered scaffold significantly enhanced cell proliferation compared to

  11. Bacterial cellulose-polyaniline nano-biocomposite: A porous media hydrogel bioanode enhancing the performance of microbial fuel cell

    Science.gov (United States)

    Mashkour, Mehrdad; Rahimnejad, Mostafa; Mashkour, Mahdi

    2016-09-01

    Microbial fuel cells (MFCs) are one of the possible renewable energy supplies which microorganisms play an active role in bio-oxidize reactions of a substrate such as glucose. Electrode materials and surface modifications are highly effective tools in enhancing MFCs' Performance. In this study, new composite anodes are fabricated. Bacterial cellulose (BC) is used as continuous phase and polyaniline (PANI) as dispersed one which is synthesized by in situ chemical oxidative polymerization on BC's fibers. With hydrogel nature of BC as a novel feature and polyaniline conductivity there meet the favorable conditions to obtain an active microbial biofilm on anode surface. Maximum power density of 117.76 mW/m2 in current density of 617 mA/m2 is achieved for BC/PANI anode. The amounts demonstrate a considerable enhancement compared with graphite plate (1 mW/m2 and 10 mA/m2).

  12. Cytotoxic activity of kenaf (Hibiscus cannabinus L.) seed extract and oil against human cancer cell lines

    Institute of Scientific and Technical Information of China (English)

    Yu Hua Wong; Wai Yan Tan; Chin Ping Tan; Kamariah Long; Kar Lin Nyam

    2014-01-01

    Objective: To examine the cytotoxic properties of both the kenaf (Hibiscus cannabinus L.) seed extract and kenaf seed oil on human cervical cancer, human breast cancer, human colon cancer and human lung cancer cell lines.Methods:kenaf seed oil on human cancer cell lines was evaluated by using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide and sulforhodamine B assays. Cell morphological changes were observed by using an inverted light microscope.Results:The in vitro cytotoxic activity of the kenaf (Hibiscus cannabinus L.) seed extract and cancer cell lines. Morphological alterations in the cell lines after KSE and KSO treatment were observed. KSE and KSO possessed effective cytotoxic activities against all the cell lines been selected.Conclusions:KSE and KSO could be potential sources of natural anti-cancer agents. Further The kenaf seed extract (KSE) exhibited a lower IC50 than kenaf seed oil (KSO) in all of the investigations on using kenaf seeds for anti-proliferative properties are warranted.

  13. Effects of 125I seed on apoptosis and cell cycle of esophageal carcinoma Eca-109 cell line

    International Nuclear Information System (INIS)

    To determine the effects of 125I seed on apoptosis and cell cycle of esophageal carcinoma Eca-109 cell line in vitro, cells were divided randomly into four groups: untreated cell (group A), treated cell with 0.2mCi 125I seed (group B), treated cell with 0.4mCi 125I seed (group C) and treated cell with 0.8mCi 125I seed (group D). After 7 days, the apoptosis and cell cycle of Eca-109 cells were detected by flow cytometry. The results showed that the apoptosis index (AI) in group B, C and D were statistically higher than that of control group A (P 0.05). G2/M phase cells increased with the dose enhancing of the 125I seed(P125I seed could induce apoptosis of esophageal carcinoma cells Eca-109 in vitro, and it may work through cell cycle G2/M phase block. (authors)

  14. Adjusting the Chemical and Physical Properties of Hydrogels Leads to Improved Stem Cell Survival and Tissue Ingrowth in Spinal Cord Injury Reconstruction: A Comparative Study of Four Methacrylate Hydrogels

    Czech Academy of Sciences Publication Activity Database

    Hejčl, Aleš; Růžička, Jiří; Kapcalová, Miroslava; Turnovcová, Karolína; Krumbholcová, Eva; Přádný, Martin; Michálek, Jiří; Cihlář, J.; Jendelová, Pavla; Syková, Eva

    2013-01-01

    Roč. 22, č. 20 (2013), s. 2794-2805. ISSN 1547-3287 R&D Projects: GA AV ČR IAA500390902; GA ČR(CZ) GPP304/11/P633; GA ČR GAP108/10/1560 Grant ostatní: GA UK(CZ) 521712 Institutional support: RVO:68378041 ; RVO:61389013 Keywords : spinal cord injury * hydrogel * mesenchymal stem cells Subject RIV: FH - Neurology; CD - Macromolecular Chemistry (UMCH-V) Impact factor: 4.202, year: 2013

  15. Tunable hydrogel composite with two-step processing in combination with innovative hardware upgrade for cell-based three-dimensional bioprinting.

    Science.gov (United States)

    Wüst, Silke; Godla, Marie E; Müller, Ralph; Hofmann, Sandra

    2014-02-01

    Three-dimensional (3-D) bioprinting is the layer-by-layer deposition of biological material with the aim of achieving stable 3-D constructs for application in tissue engineering. It is a powerful tool for the spatially directed placement of multiple materials and/or cells within the 3-D sample. Encapsulated cells are protected by the bioink during the printing process. Very few materials are available that fulfill requirements for bioprinting as well as provide adequate properties for cell encapsulation during and after the printing process. A hydrogel composite including alginate and gelatin precursors was tuned with different concentrations of hydroxyapatite (HA) and characterized in terms of rheology, swelling behavior and mechanical properties to assess the versatility of the system. Instantaneous as well as long-term structural integrity of the printed hydrogel was achieved with a two-step mechanism combining the thermosensitive properties of gelatin with chemical crosslinking of alginate. Novel syringe tip heaters were developed for improved temperature control of the bioink to avoid clogging. Human mesenchymal stem cells mixed into the hydrogel precursor survived the printing process and showed high cell viability of 85% living cells after 3 days of subsequent in vitro culture. HA enabled the visualization of the printed structures with micro-computed tomography. The inclusion of HA also favors the use of the bioink for bone tissue engineering applications. By adding factors other than HA, the composite could be used as a bioink for applications in drug delivery, microsphere deposition or soft tissue engineering. PMID:24157694

  16. In vivo study on the survival of neural stem cells transplanted into the rat brain with a collagen hydrogel that incorporates laminin-derived polypeptides.

    Science.gov (United States)

    Nakaji-Hirabayashi, Tadashi; Kato, Koichi; Iwata, Hiroo

    2013-11-20

    Poor viability of cells transplanted into the brain has been the critical problem associated with stem cell-based therapy for Parkinson's disease. To overcome this problem, a collagen hydrogel incorporating an integrin-binding protein complex was prepared and used as a carrier for neural stem cells. The protein complex consisted of two polypeptides containing the G3 domain of a laminin α1 chain and the C-terminal oligopeptide of a laminin γ1 chain. These polypeptides were fused with α-helical segments which spontaneously formed a coiled-coil heterodimer and with the collagen-binding peptide that facilitated the binding of the heterodimer to collagen networks. In this study, neural stem cells stably expressing the enhanced green fluorescent protein (EGFP) were suspended in the hydrogel and transplanted into the striatum of healthy rats. The viability of transplanted cells was evaluated by histological analysis and quantitative reverse-transcriptase polymerase chain reaction for EGFP mRNA present in the tissue explants. Our results showed that the collagen hydrogel incorporating the integrin-binding protein complex serves to improve the viability of neural stem cells (NSCs) in the early stage after transplantation into the striatum. PMID:23991904

  17. Fabrication of keratin-silica hydrogel for biomedical applications.

    Science.gov (United States)

    Kakkar, Prachi; Madhan, Balaraman

    2016-09-01

    In the recent past, keratin has been fabricated into different forms of biomaterials like scaffold, gel, sponge, film etc. In lieu of the myriad advantages of the hydrogels for biomedical applications, a keratin-silica hydrogel was fabricated using tetraethyl orthosilicate (TEOS). Textural analysis shed light on the physical properties of the fabricated hydrogel, inturn enabling the optimization of the hydrogel. The optimized keratin-silica hydrogel was found to exhibit instant springiness, optimum hardness, with ease of spreadability. Moreover, the hydrogel showed excellent swelling with highly porous microarchitecture. MTT assay and DAPI staining revealed that keratin-silica hydrogel was biocompatible with fibroblast cells. Collectively, these properties make the fabricated keratin-silica hydrogel, a suitable dressing material for biomedical applications. PMID:27207052

  18. Using of Hydrogel to Increase Maize Salt Tolerance

    International Nuclear Information System (INIS)

    Seeds of two cultivars (Giza 122 and 129) of Zea mays L. were sown in pots. Pots were divided into two sets; soils of one mixed with hydrogel and the other set considered as control. After germination, pots were irrigated by tap water or by 4500 ppm NaCI solution. The results indicated that salt stress reduced growth characters significantly. Addition of hydrogel to the soil improved growth character especially in cultivar 129, hydrogel ameliorates the harmful effect of salt on plant. In the two cultivars, proline contents increased under salt stress but the presence of hydrogel reduced these contents significantly. Also, the presence of hydrogel appeared to reduce phenol content significantly under salt stress in cultivar (129) or insignificantly in cultivar (122).The appearance or disappearance of protein bands and the alterations in peroxidase and esterase pattern could be used as molecular marker for salt stress and hydrogel

  19. The Effect of Cumin Seed Extracts against Herpes Simplex Virus Type 1 in Vero Cell Culture

    Directory of Open Access Journals (Sweden)

    Mohammad Motamedifar

    2010-12-01

    Full Text Available Background: Cumin (Cuminum cyminum L. [family Apiaceae]seed essential oil is reported to have antiseptic activity.Until now the antiviral properties of cumin seed extracts onviruses such as herpes simplex virus-1 (HSV-1 have not beenstudied. The objective of this study was to investigate the invitro effects of aqueous, methanolic and hydroalcoholic extractsof cumin seed on HSV-1 growth in Vero cell line.Methods: Antiviral activity of various concentrations aqueous,hydroalcoholic and methanolic extracts of cumin seed in Verocells were studied using plaque reduction assays. The 50%cytotoxic concentration (CC50, 50% inhibitory concentration(IC50, and therapeutic index of the effective extracts were calculated.Results: Methanolic extract of cumin seed showed a significantantiviral activity on HSV-1 in Vero cell line. Its CC50 forVero cells, IC50 and the therapeutic index for HSV-1 were0.45, 0.18 mg/mL and 2.5, respectively. Aqueous and hydroalcoholicextracts of cumin seeds showed no inhibitory effecton HSV-1.Conclusion: The methanolic extract of cumin seed producesanti-HSV-1 effect. Probable interference of phenolic compoundswith fusion of Vero cell membrane and HSV-1 envelopemight be the mechanism of such inhibitory effect. Furtherstudies are required to ascertain its in vivo antiviral propertiesand potential toxicity.Iran J Med Sci 2010; 35(4: 304-309.

  20. Development of bioartificial myocardium by electrostimulation of 3D collagen scaffolds seeded with stem cells

    OpenAIRE

    Alain Carpentier; Juan C. Chachques; Fabien Legrand; Samira Benadda; Nermine Lila; Kanwal Haneef

    2012-01-01

    Electrostimulation (ES) can be defined as a safe physical method to induce stem cell differentiation. The aim of this study is to evaluate the effectiveness of ES on bone marrow mesenchymal stem cells (BMSCs) seeded in collagen scaffolds in terms of proliferation and differentiation into cardiomyocytes. BMSCs were isolated from Wistar rats and seeded into 3D collagen type 1 templates measuring 25 x 25 x 6 mm. Bipolar in vitro ES was performed during 21 days. Electrical im...

  1. Antileukemic Potential of Momordica charantia Seed Extracts on Human Myeloid Leukemic HL60 Cells

    OpenAIRE

    Ramani Soundararajan; Punit Prabha; Umesh Rai; Aparna Dixit

    2012-01-01

    Momordica charantia (bitter gourd) has been used in the traditional system of medicine for the treatment of various diseases. Anticancer activity of M. charantia extracts has been demonstrated by numerous in vitro and in vivo studies. In the present study, we investigated the differentiation inducing potential of fractionated M. charantia seed extracts in human myeloid HL60 cells. We found that the HL60 cells treated with the fractionated seed extracts differentiated into granulocytic lineage...

  2. Injectable cell/hydrogel microspheres induce the formation of fat lobule-like microtissues and vascularized adipose tissue regeneration

    International Nuclear Information System (INIS)

    In this paper, we demonstrated that collagen/alginate microspheres could be generated by a non-contact microfabrication device and serve as excellent cell embedding and delivery devices as they were porous, injectable and able to provide growth- and differentiation-supporting matrix for human adipose-derived stem cells (hASCs). The microsphere matrix demonstrated highly porous structure and mechanical stability for as long as 90 days. hASCs demonstrated high viability after microsphere formation as well as higher proliferation and more mature adipocytes induction compared to two-dimensional culture. After four weeks culture in adipogenic differentiation medium, adipocytes/collagen/alginate microspheres highly mimicking natural fat lobules were obtained and injected subcutaneously into the head of node mice. The in vivo study demonstrated vascularized adipose tissue formation in four weeks. The regenerated vasculature among the transplantation showed functional anastomosis with host vasculature, suggesting that these cell/hydrogel microspheres present injectable adipocytes delivery devices capable of generating vascularized adipose tissue in vivo and thus suitable for cell transplantation and tissue regeneration. (paper)

  3. FGL-functionalized self-assembling nanofiber hydrogel as a scaffold for spinal cord-derived neural stem cells

    International Nuclear Information System (INIS)

    A class of designed self-assembling peptide nanofiber scaffolds has been shown to be a good biomimetic material in tissue engineering. Here, we specifically made a new peptide hydrogel scaffold FGLmx by mixing the pure RADA16 and designer functional peptide RADA16-FGL solution, and we analyzed the physiochemical properties of each peptide with atomic force microscopy (AFM) and circular dichroism (CD). In addition, we examined the biocompatibility and bioactivity of FGLmx as well as RADA16 scaffold on spinal cord-derived neural stem cells (SC-NSCs) isolated from neonatal rats. Our results showed that RADA16-FGL displayed a weaker β-sheet structure and FGLmx could self-assemble into nanofibrous morphology. Moreover, we found that FGLmx was not only noncytotoxic to SC-NSCs but also promoted SC-NSC proliferation and migration into the three-dimensional (3-D) scaffold, meanwhile, the adhesion and lineage differentiation of SC-NSCs on FGLmx were similar to that on RADA16. Our results indicated that the FGL-functionalized peptide scaffold might be very beneficial for tissue engineering and suggested its further application for spinal cord injury (SCI) repair. - Highlights: • RADA16 and RADA16-FGL peptides were synthesized and characterized. • Rat spinal cord neural stem cells were successfully isolated and characterized. • We provided an induction method for mixed differentiation of neural stem cells. • FGL scaffold had good biocompatibility and bioactivity with neural stem cells

  4. Steric Interference of Adhesion Supports In-Vitro Chondrogenesis of Mesenchymal Stem Cells on Hydrogels for Cartilage Repair

    Science.gov (United States)

    Goldshmid, Revital; Cohen, Shlomit; Shachaf, Yonatan; Kupershmit, Ilana; Sarig-Nadir, Offra; Seliktar, Dror; Wechsler, Roni

    2015-01-01

    Recent studies suggest the presence of cell adhesion motifs found in structural proteins can inhibit chondrogenesis. In this context, the current study aims to determine if a polyethylene glycol (PEG)-modified fibrinogen matrix could support better chondrogenesis of human bone marrow mesenchymal stem cells (BM-MSC) based on steric interference of adhesion, when compared to a natural fibrin matrix. Hydrogels used as substrates for two-dimensional (2D) BM-MSC cultures under chondrogenic conditions were made from cross-linked PEG-fibrinogen (PF) and compared to thrombin-activated fibrin. Cell morphology, protein expression, DNA and sulfated proteoglycan (GAG) content were correlated to substrate properties such as stiffness and adhesiveness. Cell aggregation and chondrogenic markers, including collagen II and aggrecan, were observed on all PF substrates but not on fibrin. Shielding fibrinogen’s adhesion domains and increasing stiffness of the material are likely contributing factors that cause the BM-MSCs to display a more chondrogenic phenotype. One composition of PF corresponding to GelrinC™—a product cleared in the EU for cartilage repair—was found to be optimal for supporting chondrogenic differentiation of BM-MSC while minimizing hypertrophy (collagen X). These findings suggest that semi-synthetic biomaterials based on ECM proteins can be designed to favourably affect BM-MSC towards repair processes involving chondrogenesis. PMID:26411496

  5. ANTICANCER ACTIVITY OF PONGAMIA GLABRA V. SEED OIL EXTRACT AGAINST SELECTED HUMAN CANCER CELL LINES

    Directory of Open Access Journals (Sweden)

    Chinnasamy Arulvasu

    2012-08-01

    Full Text Available Screening of the seed oil extract from Pongamia glabra V. (Fabaceae has been carried out for antiproliferative activity of cancer cells. The seed oil was extracted with methanol and then persuasive activity was tested on human cancer cell lines MCF-7 and HeLa. The cell growth inhibitory effects of seed oil extract was observed. The cell viability was assessed using trypan blue dye exclusion method and 3-(4, 5- Dimethyl thiazol-2yl-2, 5-dimethyltetrazolium bromide (MTT assay. The IC50 value of the methanolic seed oil extract against MCF-7 and HeLa was found to be 6 mg/ml and 6 mg/ml respectively after 48 hours of incubation. The P.glabra seed oil extract increased the proportion of DNA fragmentation in MCF-7 and HeLa cancer cell lines. Moreover, the inhibitory effect is correlated with DNA fragmentation. These results suggest that the P.glabra seed oil extract has an inhibitory effect on human cancer cell lines MCF-7 and HeLa.

  6. Effect of cold storage on collagen-based hydrogels for the three-dimensional culture of adipose-derived stem cells

    International Nuclear Information System (INIS)

    Collagen gels have been extensively used as three-dimensional (3D) cell culture systems. To enhance their mechanical properties, the manufacture of collagen-based gels with agarose has been proposed. However, little is known about the stability of these gels under cold storage conditions. The consequences of cold storage on biological tissues for clinical applications are known to be significant; yet, they have not been considered on hydrogels used for in vitro experiments. This work studies the effect of extended cold storage on the stability of collagen and collagen-agarose hydrogels using rheometry and scanning electron microscopy. In addition, cell-matrix interactions of adipose-derived stem cells (ADSC) have been studied using these gels. Results show that both the storage modulus (G′) and loss modulus (G″) of pure collagen gels gradually decrease with extended cold storage along the 30 days of the study, while G′ and G″ increase in collagen-agarose gels under the same conditions. Moreover, significant changes in both moduli of collagen-agarose gels were only found after 30 days of cold storage, while in the case of collagen gels significant changes were already detected after 7 days. Finally, a reduction in the ability of ADSC to remodel the gel after prolonged cold storage was observed. To the best of our knowledge, this is the first work proving that cold storage of hydrogels prior to cell culture might have a significant impact on their mechanical properties and cell–matrix interactions. (paper)

  7. BMP2 induced osteogenic differentiation of human umbilical cord stem cells in a peptide-based hydrogel scaffold

    Science.gov (United States)

    Lakshmana, Shruthi M.

    Craniofacial tissue loss due to traumatic injuries and congenital defects is a major clinical problem around the world. Cleft palate is the second most common congenital malformation in the United States occurring with an incidence of 1 in 700. Some of the problems associated with this defect are feeding difficulties, speech abnormalities and dentofacial anomalies. Current treatment protocol offers repeated surgeries with extended healing time. Our long-term goal is to regenerate bone in the palatal region using tissue-engineering approaches. Bone tissue engineering utilizes osteogenic cells, osteoconductive scaffolds and osteoinductive signals. Mesenchymal stem cells derived from human umbilical cord (HUMSCs) are highly proliferative with the ability to differentiate into osteogenic precursor cells. The primary objective of the study was to characterize HUMSCs and culture them in a 3D hydrogel scaffold and investigate their osteogenic potential. PuraMatrix(TM) is an injectable 3D nanofiber scaffold capable of self-assembly when exposed to physiologic conditions. Our second objective was to investigate the effect of Bone Morphogenic Protein 2 (BMP2) in enhancing the osteogenic differentiation of HUMSCs encapsulated in PuraMatrix(TM). We isolated cells isolated from Wharton's Jelly region of the umbilical cord obtained from NDRI (New York, NY). Isolated cells satisfied the minimal criteria for mesenchymal stem cells (MSCs) as defined by International Society of Cell Therapy in terms of plastic adherence, fibroblastic phenotype, surface marker expression and osteogenic differentiation. Flow Cytometry analysis showed that cells were positive for CD73, CD90 and CD105 while negative for hematopoietic marker CD34. Alkaline phosphatase activity (ALP) of HUMSCs showed peak activity at 2 weeks (p<0.05). Cells were encapsulated in 0.2% PuraMatrix(TM) at cell densities of 10x104, 20x104, 40x10 4 and 80x104. Cell viability with WST and proliferation with Live-Dead cell assays

  8. Biologically engineered protein-graft-poly(ethylene glycol) hydrogels: A cell-adhesive and plasmin-degradable biosynthetic material for tissue repair

    Science.gov (United States)

    Halstenberg, Sven

    2002-01-01

    The goal of the research presented in this dissertation was to create a biomimetic artificial material that exhibits functions of extracellular matrix relevant for improved nerve regeneration. Neural adhesion peptides were photoimmobilized on highly crosslinked poly(ethylene glycol)-based substrates that were otherwise non-adhesive. Neurons adhered in two-dimensional patterns for eleven hours, but no neurites extended. To enable neurite extension and nerve regeneration in three dimensions, and to address the need for specifically cell adhesive and cell degradable materials for clinical applications in tissue repair in general, an artificial protein was recombinantly expressed and purified that consisted of a repeating amino acid sequence based on fibrinogen and anti-thrombin III. The recombinant protein contained integrin-binding RGD sites, plasmin degradation sites, heparin binding sites, and six thiol-containing cysteine residues as grafting sites for poly(ethylene glycol) diacrylate via Michael-type conjugate addition. The resulting protein-graft-poly(ethylene glycol)acrylates were crosslinked by photopolymerization to form hydrogels. Although three-dimensional, RGD mediated and serine protease-dependent ingrowth of human fibroblasts into protein-graft-poly(ethylene glycol) hydrogels occurred, only surface neurite outgrowth was observed from chick dorsal root ganglia. Axonal outgrowth depended on the concentration of matrix-bound heparin, suggesting that improved mechanical strength of the hydrogels and possible immobilization of neuroactive factors due to the presence of heparin promoted neurite outgrowth. Together, the above results show that specific biological functions can be harnessed by protein-graft-poly(ethylene glycol) hydrogels to serve as matrices for tissue repair and regeneration. In particular, the two design objectives, specific cell adhesion and degradability by cell-associated proteases, were fulfilled by the material. In the future, this and

  9. RGDS-functionalized polyethylene glycol hydrogel-coated magnetic iron oxide nanoparticles enhance specific intracellular uptake by HeLa cells

    OpenAIRE

    Nazli C; Ergenc TI; Yar Y; Acar HY; Kizilel S

    2012-01-01

    © 2012 Nazli et al, publisher and licensee Dove Medical Press Ltd. This is an Open Access article which permits unrestricted noncommercial use, provided the original work is properly cited. International Journal of Nanomedicine 2012:7 1903–1920 International Journal of Nanomedicine RGDS-functionalized polyethylene glycol hydrogel-coated magnetic iron oxide nanoparticles enhance specific intracellular uptake by HeLa cells Caner Nazli1 Tugba Ipek Ergenc2 Yasemin Ya...

  10. The influence of electrical charge on the growth of bone marrow stromal cells in macroporous polymer hydrogels based on 2-hydroxyethylmethacrylate and in polyelectrolyte complexes

    Czech Academy of Sciences Publication Activity Database

    Lesný, P.; Přádný, Martin; Fiala, J.; Michálek, Jiří; Syková, E.

    Leipzig : University of Leipzig, Biomedical Biotechnological Center, 2003. s. 865. [World Congress on Regenerative Medicine /1./. 09.05.2003-12.05.2003, Leipzig] R&D Projects: GA ČR GA304/03/1189; GA MŠk LN00A065; GA ČR GA203/01/0737 Institutional research plan: CEZ:AV0Z4050913 Keywords : macroporous polymer hydrogels * 2-hydroxyethylmethacrylate * bone marrow stromal cells Subject RIV: FJ - Surgery incl. Transplants

  11. Engineered 3D bioimplants using elastomeric scaffold, self-assembling peptide hydrogel, and adipose tissue-derived progenitor cells for cardiac regeneration

    OpenAIRE

    Soler-Botija, Carolina; Bagó, Juli R; Llucià-Valldeperas, Aida; Vallés-Lluch, Ana; Castells-Sala, Cristina; Martínez-Ramos, Cristina; Fernández-Muiños, Teresa; Chachques, Juan Carlos; Pradas, Manuel Monleón; Semino, Carlos E; Bayes-Genis, Antoni

    2014-01-01

    Contractile restoration of myocardial scars remains a challenge with important clinical implications. Here, a combination of porous elastomeric membrane, peptide hydrogel, and subcutaneous adipose tissue-derived progenitor cells (subATDPCs) was designed and evaluated as a bioimplant for cardiac regeneration in a mouse model of myocardial infarction. SubATDPCs were doubly transduced with lentiviral vectors to express bioluminescent-fluorescent reporters driven by constitutively active, cardiac...

  12. Cranberry and Grape Seed Extracts Inhibit the Proliferative Phenotype of Oral Squamous Cell Carcinomas

    Directory of Open Access Journals (Sweden)

    Kourt Chatelain

    2011-01-01

    Full Text Available Proanthocyanidins, compounds highly concentrated in dietary fruits, such as cranberries and grapes, demonstrate significant cancer prevention potential against many types of cancer. The objective of this study was to evaluate cranberry and grape seed extracts to quantitate and compare their anti-proliferative effects on the most common type of oral cancer, oral squamous cell carcinoma. Using two well-characterized oral squamous cell carcinoma cell lines, CAL27 and SCC25, assays were performed to evaluate the effects of cranberry and grape seed extract on phenotypic behaviors of these oral cancers. The proliferation of both oral cancer cell lines was significantly inhibited by the administration of cranberry and grape seed extracts, in a dose-dependent manner. In addition, key regulators of apoptosis, caspase-2 and caspase-8, were concomitantly up-regulated by these treatments. However, cranberry and grape seed extracts elicited differential effects on cell adhesion, cell morphology, and cell cycle regulatory pathways. This study represents one of the first comparative investigations of cranberry and grape seed extracts and their anti-proliferative effects on oral cancers. Previous findings using purified proanthocyanidin from grape seed extract demonstrated more prominent growth inhibition, as well as apoptosis-inducing, properties on CAL27 cells. These observations provide evidence that cranberry and grape seed extracts not only inhibit oral cancer proliferation but also that the mechanism of this inhibition may function by triggering key apoptotic regulators in these cell lines. This information will be of benefit to researchers interested in elucidating which dietary components are central to mechanisms involved in the mediation of oral carcinogenesis and progression.

  13. Orthogonal Enzymatic Reactions to Control Supramolecular Hydrogelations%Orthogonal Enzymatic Reactions to Control Supramolecular Hydrogelations

    Institute of Scientific and Technical Information of China (English)

    陈国钦; 任春华; 王玲; 徐兵; 杨志谋

    2012-01-01

    Enzyme-responsive hydrogels have great potential in applications of controlled drug release, tissue engineering, etc. In this study, we reported on a supramolecular hydrogel that showed responses to two enzymes, phosphatase which was used to form the hydrogels and esterase which could trigger gelsol phase transitions. The gelation process and visco-elasticity property of the resulting gel, morphology of the nanostructures in hydrogel, and peptide conformation in the self-assembled nanostructure were characterized by theology, transmission electron microscope (TEM), and circular dichroism (CD), respectively. Potential application of the enzyme-responsive hydrogel in drug release was also demonstrated in this study. Though only one potential application of drug release was proved in this study, the responsive hydrogel system in this study might have potentials for the applications in fields of cell culture, controlled-drug release, etc.

  14. Behavior of Jatropha curcas L. seeds under osmotic stress: germination and cell cycle activity

    Directory of Open Access Journals (Sweden)

    Cristiane Dantas de Brito

    2015-08-01

    Full Text Available Jatropha curcas is an oil-rich Euphorbiaceae seed species renowned for its apparent tolerance to environmental stresses. It is considered a promising source of renewable feedstock for biodiesel production in the Brazilian semiarid region where crop establishment requires a better understanding of the mechanisms leading to proper seed and plant behavior under water restrictive conditions. This study describes physiological and cytological profiles of J. curcas seeds imbibed in water restriction conditions by means of osmotic stress or osmoconditioning. Seeds were characterized by size, weight, moisture content and dry mass, germinability, and cell cycle activation by means of tubulin and microtubule cytoskeleton accumulation. Osmoconditioning at -0.8 MPa did not induce priming effects as it did not improve the physiological quality of the seed lots. Western blotting and immunocytochemical analysis revealed an increasing accumulation of tubulin and microtubule cytoskeleton in seeds imbibed in water for 48h onwards, culminating in the onset of mitotic configurations after germination. Only cortical microtubules were observed during seed osmoconditioning, whereas mitotic microtubules only occurred after re-imbibition of osmoconditioned seeds in water and subsequent germination.

  15. Cetuximab affects the capacity of DNA repair in colorectal cancer cells after 125I seeds irradiation

    International Nuclear Information System (INIS)

    Objective: To investigate the effect of C225 on DNA repair and molecular pathways in CL187 colorectal cancer cells after irradiated by 125I radioactive seeds. Methods: In the experiment involved were four groups:control group, 100 nmol/L C225 treatment group,125I radioactive seeds continuous low-dose rate irradiation group and C225 combined with 125I radioactive seeds continuous low dose rate irradiation group. Cells were collected at 48 h after 4 Gy irradiation, and γH2AX foci/cell and γH2AX foci positive cells were counted with immunofluorescence. At the same time, DNA repair proteins were detected by Western blot. Cells were analyzed immediately after 4 Gy irradiation,and changes in EGFR downstream signaling molecules were detected by Western blot. Results: Compared with 125I seeds irradiated cells,cells treated with C225 and 125I seeds irradiation showed more γH2AX foci per cell (t=8.0, P=0.05), and more γH2AX foci positive cells (t=6.8, P<0.05) and less expression of Ku70 (t=6.6, P<0.05) and DNA-PKcs (t=5.6, P<0.05). Combined with 125I-CLDR irradiation, C225 reduced cellular EGFR level (t=4.9, P<0.05) and inhibited the activation of Akt (t=5.5, P<0.05). Conclusions: In the condition of 125I seeds irradiation, C225 reduced the expression of Ku70 and DNA-PKcs, inhibited the activation of Akt and attenuated the DNA damage repair capacity in CL187 colorectal cancer cells. (authors)

  16. Direct electron transfer from native human hemoglobin using a glassy carbon electrode modified with chitosan and a poly(N,N-diethylacrylamide) hydrogel containing red blood cells

    International Nuclear Information System (INIS)

    We report on a new whole cell biosensor for hydrogen peroxide. A chitosan-coated glassy carbon electrode (GCE) was modified with poly(N,N-diethylacrylamide) (PDEA) hydrogel containing human red blood cells (RBCs). The morphology of RBCs in the hydrogel was investigated using scanning electron microscopy (SEM). Fourier transform infrared spectroscopy and SEM were applied to study the association of the PDEA chains and RBCs. Uncompromised bioactivity of native human hemoglobin in the RBCs on the modified GCE was confirmed by cyclic voltammetry. The modified electrode showed a faster electron transfer rate and better electrocatalytic activity in the reduction of H2O2 than previously reported sensors. A linear relationship is found between the response to H2O2 and its concentration in the range from 0.11 μM to 12.7 mM. The detection limit is 55 nM at an SNR of 3. It is assumed that the improvement of the biosensor results from the porosity and conductivity of the PDEA hydrogel. (author)

  17. Poloxamer bioadhesive hydrogel for buccal drug delivery: Cytotoxicity and trans-epithelial permeability evaluations using TR146 human buccal epithelial cell line.

    Science.gov (United States)

    Zeng, Ni; Mignet, Nathalie; Dumortier, Gilles; Olivier, Elodie; Seguin, Johanne; Maury, Marc; Scherman, Daniel; Rat, Patrice; Boudy, Vincent

    2015-11-30

    A salbutamol sulfate (SS)-Poloxamer bioadhesive hydrogel specially developed for buccal administration was investigated by studying interactions with TR146 human buccal epithelium cells (i.e. cellular toxicity (i) and trans-epithelial SS diffusion (ii)). The assessment of cell viability (MTT, Alamar Blue), membrane integrity (Neutral Red), and apoptosis assay (Hoechst 33342), were performed and associated to Digital Holographic Microscopy analysis. After the treatment of 2h, SS solution induced drastic cellular alterations that were prevented by hydrogels in relation with the concentrations of poloxamer and xanthan gum. The formulation containing P407 19%/P188 1%/Satiaxane 0.1% showed the best tolerance after single and multiple administrations and significantly reduced the trans-epithelial permeability from 5.00±0.29 (×10(3)) (SS solution) to 1.83±0.22 cm/h. Digital Holographic Microscopy images in good agreement with the viability data confirmed the great interest of this direct technique. In conclusion, the proposed hydrogels represent a safe and efficient buccal drug delivery platform. PMID:26403384

  18. Anatomy and cell wall polysaccharides of almond (Prunus dulcis D. A. Webb) seeds

    OpenAIRE

    Dourado, Fernando; Barros, António; Mota, M.; Coimbra, Manuel A.; Gama, F. M.

    2004-01-01

    The anatomy of Prunus dulcis was analyzed by applying several differential staining techniques and light microscopy. Prunus dulcis seed has a thin and structurally complex seed coat, with lignified cellulosic tissue. The embryo has two voluminous cotyledons. Cotyledon cells have a high number of protein and lipid bodies, some of which have phytin. The provascular tissue, located in the cotyledons, is oriented in small bundles perpendicular to the transverse embryonic axis. Prunus ...

  19. PRAGMATIC HYDROGELS

    OpenAIRE

    Patil S.A.; Rane B.R.; Bakliwal S.R.; Pawar S.P.

    2011-01-01

    Man has always been plagued with many ailments and diseases. The field of pharmaceutical science has today become more invaluable in helping to keep us healthy and prevent disease. The availability of large molecular weight protein and peptide-based drugs due to the recent advances has given us a new ways to treat a number of diseases. I wish to present new and promising techniques for the production of drug and protein delivery formulations that have been developed that is Hydrogel. These ar...

  20. Fiber diameter and seeding density influence chondrogenic differentiation of mesenchymal stem cells seeded on electrospun poly(ε-caprolactone) scaffolds

    International Nuclear Information System (INIS)

    Chondrogenic differentiation of mesenchymal stem cells is strongly influenced by the surrounding chemical and structural milieu. Since the majority of the native cartilage extracellular matrix is composed of nanofibrous collagen fibrils, much of recent cartilage tissue engineering research has focused on developing and utilizing scaffolds with similar nanoscale architecture. However, current literature lacks consensus regarding the ideal fiber diameter, with differences in culture conditions making it difficult to compare between studies. Here, we aimed to develop a more thorough understanding of how cell–cell and cell-biomaterial interactions drive in vitro chondrogenic differentiation of bone-marrow-derived mesenchymal stem cells (MSCs). Electrospun poly(ε-caprolactone) microfibers (4.3  ±  0.8 µm diameter, 90 μm2 pore size) and nanofibers (440  ±  20 nm diameter, 1.2 μm2 pore size) were seeded with MSCs at initial densities ranging from 1  ×  105 to 4  ×  106 cells cm−3-scaffold and cultured under transforming growth factor-β (TGF-β) induced chondrogenic conditions for 3 or 6 weeks. Chondrogenic gene expression, cellular proliferation, as well as sulfated glycosaminoglycan and collagen production were enhanced on microfiber in comparison to nanofiber scaffolds, with high initial seeding densities being required for significant chondrogenic differentiation and extracellular matrix deposition. Both cell–cell and cell–material interactions appear to play important roles in chondrogenic differentiation of MSCs in vitro and consideration of several variables simultaneously is essential for understanding cell behavior in order to develop an optimal tissue engineering strategy. (paper)

  1. Application of Vascular grafts od Polyvinyl alcohol hydrogel associated to mesenchymal stem cells from whartons jelly in an animal model.

    OpenAIRE

    Alexandre, Nuno; Lopes, Ascensão; Nunes, Natacha; Amorim, Irina; Maurício, Ana Colette; Santos, José Domingos; Luís, Ana Lúcia

    2013-01-01

    Application of vascular grafts of the polyvinyl alcohol hydrogel (PVA) associated with MSCs from Wharton jelly in an animal model (sheep). N Alexandre, MA Lopes, N Fernandes, M Rodrigues, I Amorim, AC Mauricio, AL Luís Introduction: There is a great demand for new artificial vascular grafts of small diameter (< 6 mm) due to the functional limitations of the currently used biomaterials (ePTFE and Dacron). Polyvinyl alcohol hydrogel (PVA) is a biomaterial that has been used for several b...

  2. Controlled Release of Simvastatin from In situ Forming Hydrogel Triggers Bone Formation in MC3T3-E1 Cells

    OpenAIRE

    Park, Yoon Shin; David, Allan E.; Park, Kyung Min; Lin, Chia-Ying; Than, Khoi D.; Lee, Kyuri; Park, Jun Beom; Jo, Inho; Park, Ki Dong; Yang, Victor C.

    2012-01-01

    Simvastatin (SIM), a drug commonly administered for the treatment of hypercholesterolemia, has been recently reported to induce bone regeneration/formation. In this study, we investigated the properties of hydrogel composed of gelatin–poly(ethylene glycol)–tyramine (GPT) as an efficient SIM delivery vehicle that can trigger osteogenic differentiation. Sustained delivery of SIM was achieved through its encapsulation in an injectable, biodegradable GPT-hydrogel. Cross-linking of the gelatin-bas...

  3. Hydrogel-laden paper scaffold system for origami-based tissue engineering.

    Science.gov (United States)

    Kim, Su-Hwan; Lee, Hak Rae; Yu, Seung Jung; Han, Min-Eui; Lee, Doh Young; Kim, Soo Yeon; Ahn, Hee-Jin; Han, Mi-Jung; Lee, Tae-Ik; Kim, Taek-Soo; Kwon, Seong Keun; Im, Sung Gap; Hwang, Nathaniel S

    2015-12-15

    In this study, we present a method for assembling biofunctionalized paper into a multiform structured scaffold system for reliable tissue regeneration using an origami-based approach. The surface of a paper was conformally modified with a poly(styrene-co-maleic anhydride) layer via initiated chemical vapor deposition followed by the immobilization of poly-l-lysine (PLL) and deposition of Ca(2+). This procedure ensures the formation of alginate hydrogel on the paper due to Ca(2+) diffusion. Furthermore, strong adhesion of the alginate hydrogel on the paper onto the paper substrate was achieved due to an electrostatic interaction between the alginate and PLL. The developed scaffold system was versatile and allowed area-selective cell seeding. Also, the hydrogel-laden paper could be folded freely into 3D tissue-like structures using a simple origami-based method. The cylindrically constructed paper scaffold system with chondrocytes was applied into a three-ring defect trachea in rabbits. The transplanted engineered tissues replaced the native trachea without stenosis after 4 wks. As for the custom-built scaffold system, the hydrogel-laden paper system will provide a robust and facile method for the formation of tissues mimicking native tissue constructs. PMID:26621717

  4. Thin Film Solar Cells Prepared on Low Thermal Budget Polycrystalline Silicon Seed Layers

    Science.gov (United States)

    Jaeger, Christian; Matsui, Takuya; Takeuchi, Masayoshi; Karasawa, Minoru; Kondo, Michio; Stutzmann, Martin

    2010-11-01

    In this work, we present data from solar cells with Si grown by plasma-enhanced chemical vapour deposition as the absorber material prepared on polycrystalline silicon seed layers. For the seed layer preparation, the reverse aluminum-induced layer exchange (R-ALILE) process is used. In contrast to the conventional ALILE process, the R-ALILE results in a smooth top surface of the polycrystalline silicon and to the automatic formation of an Al-back contact, which both are beneficial for solar cell preparation. We found that the proper treatment of the seed layers prior to the absorber layer deposition is crucial for a good solar cell performance. Here, we investigated different wet chemical methods (HF-solution, Al-etch) and the influence of an H2-plasma treatment. Furthermore, we studied the influence of an additional Ag/indium tin oxide (ITO)-back contact on the solar cell performance. We find that solar cell efficiencies over 5% can be obtained using the presented seed layer concept. The results obtained in this work can help to improve the epitaxial overgrowth of seed layers.

  5. FGL-functionalized self-assembling nanofiber hydrogel as a scaffold for spinal cord-derived neural stem cells

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Jian [Department of Orthopedics, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022 (China); Zheng, Jin [Department of Neurology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022 (China); Zheng, Qixin, E-mail: zheng-qx@163.com [Department of Orthopedics, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022 (China); Wu, Yongchao; Wu, Bin; Huang, Shuai; Fang, Weizhi; Guo, Xiaodong [Department of Orthopedics, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022 (China)

    2015-01-01

    A class of designed self-assembling peptide nanofiber scaffolds has been shown to be a good biomimetic material in tissue engineering. Here, we specifically made a new peptide hydrogel scaffold FGLmx by mixing the pure RADA{sub 16} and designer functional peptide RADA{sub 16}-FGL solution, and we analyzed the physiochemical properties of each peptide with atomic force microscopy (AFM) and circular dichroism (CD). In addition, we examined the biocompatibility and bioactivity of FGLmx as well as RADA{sub 16} scaffold on spinal cord-derived neural stem cells (SC-NSCs) isolated from neonatal rats. Our results showed that RADA{sub 16}-FGL displayed a weaker β-sheet structure and FGLmx could self-assemble into nanofibrous morphology. Moreover, we found that FGLmx was not only noncytotoxic to SC-NSCs but also promoted SC-NSC proliferation and migration into the three-dimensional (3-D) scaffold, meanwhile, the adhesion and lineage differentiation of SC-NSCs on FGLmx were similar to that on RADA{sub 16}. Our results indicated that the FGL-functionalized peptide scaffold might be very beneficial for tissue engineering and suggested its further application for spinal cord injury (SCI) repair. - Highlights: • RADA{sub 16} and RADA{sub 16}-FGL peptides were synthesized and characterized. • Rat spinal cord neural stem cells were successfully isolated and characterized. • We provided an induction method for mixed differentiation of neural stem cells. • FGL scaffold had good biocompatibility and bioactivity with neural stem cells.

  6. Enzyme-catalysed assembly of DNA hydrogel

    Science.gov (United States)

    Um, Soong Ho; Lee, Jong Bum; Park, Nokyoung; Kwon, Sang Yeon; Umbach, Christopher C.; Luo, Dan

    2006-10-01

    DNA is a remarkable polymer that can be manipulated by a large number of molecular tools including enzymes. A variety of geometric objects, periodic arrays and nanoscale devices have been constructed. Previously we synthesized dendrimer-like DNA and DNA nanobarcodes from branched DNA via ligases. Here we report the construction of a hydrogel entirely from branched DNA that are three-dimensional and can be crosslinked in nature. These DNA hydrogels were biocompatible, biodegradable, inexpensive to fabricate and easily moulded into desired shapes and sizes. The distinct difference of the DNA hydrogel to other bio-inspired hydrogels (including peptide-based, alginate-based and DNA (linear)-polyacrylamide hydrogels) is that the crosslinking is realized via efficient, ligase-mediated reactions. The advantage is that the gelling processes are achieved under physiological conditions and the encapsulations are accomplished in situ-drugs including proteins and even live mammalian cells can be encapsulated in the liquid phase eliminating the drug-loading step and also avoiding denaturing conditions. Fine tuning of these hydrogels is easily accomplished by adjusting the initial concentrations and types of branched DNA monomers, thus allowing the hydrogels to be tailored for specific applications such as controlled drug delivery, tissue engineering, 3D cell culture, cell transplant therapy and other biomedical applications.

  7. The dynamics of surface acoustic wave-driven scaffold cell seeding.

    NARCIS (Netherlands)

    Bok, M.H.H.; Li, H.; Yeo, L.Y.; Friend, J.R.

    2009-01-01

    Flow visualization using fluorescent microparticles and cell viability investigations are carried out to examine the mechanisms by which cells are seeded into scaffolds driven by surface acoustic waves. The former consists of observing both the external flow prior to the entry of the suspension into

  8. Novel Hydrogels from Renewable Resources

    Science.gov (United States)

    Karaaslan, Muzafer Ahmet

    2011-12-01

    The cell wall of most plant biomass from forest and agricultural resources consists of three major polymers, cellulose, hemicellulose and lignin. Of these, hemicelluloses have gained increasing attention as sustainable raw materials. In the first part of this study, novel pH-sensitive semi-IPN hydrogels based on hemicelluloses and chitosan were prepared using glutaraldehyde as the crosslinking agent. The hemicellulose isolated from aspen was analyzed for sugar content by HPLC, and its molecular weight distribution was determined by high performance size exclusion chromatography. Results revealed that hemicellulose had a broad molecular weight distribution with a fair amount of polymeric units, together with xylose, arabinose and glucose. The effect of hemicellulose content on mechanical properties and swelling behavior of hydrogels were investigated. The semi-IPNs hydrogel structure was confirmed by FT-IR, X-ray study and ninhydrin assay method. X-ray analysis showed that higher hemicellulose contents yielded higher crystallinity. Mechanical properties were mainly dependent on the crosslink density and average molecular weight between crosslinks. Swelling ratios increased with increasing hemicellulose content and were high at low pH values due to repulsion between similarly charged groups. In vitro release study of a model drug showed that these semi-IPN hydrogels could be used for controlled drug delivery into gastric fluid. The aim of the second part of this study was to control the crosslink density and the mechanical properties of hemicellulose/chitosan semi-IPN hydrogels by changing the crosslinking sequence. It has been hypothesized that by performing the crosslinking step before introducing hemicellulose, covalent crosslinking of chitosan would not be hindered and therefore more and/or shorter crosslinks could be formed. Furthermore, additional secondary interactions and crystalline domains introduced through hemicellulose could be favorable in terms of

  9. Photochemical Patterning of Ionically Cross-Linked Hydrogels

    Directory of Open Access Journals (Sweden)

    Marion Bruchet

    2013-08-01

    Full Text Available Iron(III cross-linked alginate hydrogel incorporating sodium lactate undergoes photoinduced degradation, thus serving as a biocompatible positive photoresist suitable for photochemical patterning. Alternatively, surface etching of iron(III cross-linked hydrogel contacting lactic acid solution can be used for controlling the thickness of the photochemical pattering. Due to biocompatibility, both of these approaches appear potentially useful for advanced manipulation with cell cultures including growing cells on the surface or entrapping them within the hydrogel.

  10. Mesenchymal Stem Cell Seeding of Porcine Small Intestinal Submucosal Extracellular Matrix for Cardiovascular Applications

    Science.gov (United States)

    Chang, Chia Wei; Petrie, Tye; Clark, Alycia; Lin, Xin; Sondergaard, Claus S.; Griffiths, Leigh G.

    2016-01-01

    In this study, we investigate the translational potential of a novel combined construct using an FDA-approved decellularized porcine small intestinal submucosa extracellular matrix (SIS-ECM) seeded with human or porcine mesenchymal stem cells (MSCs) for cardiovascular indications. With the emerging success of individual component in various clinical applications, the combination of SIS-ECM with MSCs could provide additional therapeutic potential compared to individual components alone for cardiovascular repair. We tested the in vitro effects of MSC-seeding on SIS-ECM on resultant construct structure/function properties and MSC phenotypes. Additionally, we evaluated the ability of porcine MSCs to modulate recipient graft-specific response towards SIS-ECM in a porcine cardiac patch in vivo model. Specifically, we determined: 1) in vitro loading-capacity of human MSCs on SIS-ECM, 2) effect of cell seeding on SIS-ECM structure, compositions and mechanical properties, 3) effect of SIS-ECM seeding on human MSC phenotypes and differentiation potential, and 4) optimal orientation and dose of porcine MSCs seeded SIS-ECM for an in vivo cardiac application. In this study, histological structure, biochemical compositions and mechanical properties of the FDA-approved SIS-ECM biomaterial were retained following MSCs repopulation in vitro. Similarly, the cellular phenotypes and differentiation potential of MSCs were preserved following seeding on SIS-ECM. In a porcine in vivo patch study, the presence of porcine MSCs on SIS-ECM significantly reduced adaptive T cell response regardless of cell dose and orientation compared to SIS-ECM alone. These findings substantiate the clinical translational potential of combined SIS-ECM seeded with MSCs as a promising therapeutic candidate for cardiac applications. PMID:27070546

  11. Pepper seed extract suppresses invasion and migration of human breast cancer cells.

    Science.gov (United States)

    Kim, Hyeon-A; Kim, Min-Sook; Kim, Sang-Hyun; Kim, Yoo Kyeong

    2014-01-01

    This study was performed to determine the antimetastatic activities of chili pepper seed on human breast cancer cells. The water extract of chili pepper seeds was prepared and it contained a substantial amount of phenols (131.12 mg%) and no capsaicinoids. Pepper seed extract (PSE) suppressed the proliferation of MDA-MB-231 and MCF-7 cells at the concentration of 10, 25, and 50 μg/ml (MDA-MB-231: IC50 = 20.1 μg/ml, MCF-7: IC50 = 14.7 μg/ml). PSE increased the expression level of E-cadherin up to 1.2-fold of the control in MCF-7 cells. PSE also decreased the secretion of matrix metalloproteinase (MMP)-2 and MMP-9 in MDA-MB-231 and MCF-7 cells at the concentration of 25 and 50 μg/ml. PSE treatment significantly suppressed the invasion of MDA-MB-231 and MCF-7 cells in a dose-dependent manner. The motility of cancer cells was apparently retarded in the wound healing assay by the PSE treatment. Although our data collectively demonstrate that PSE inhibits invasion and migration of breast cancer cells, further study is needed to identify specific mechanisms and bioactive components contributing to antimetastatic effects of chili pepper seed. PMID:24341783

  12. A 3D printed microfluidic device for production of functionalized hydrogel microcapsules for culture and differentiation of human Neuronal Stem Cells (hNSC).

    Science.gov (United States)

    Alessandri, Kevin; Feyeux, Maxime; Gurchenkov, Basile; Delgado, Christophe; Trushko, Anastasiya; Krause, Karl-Heinz; Vignjević, Daniela; Nassoy, Pierre; Roux, Aurélien

    2016-04-26

    We present here a microfluidic device that generates sub-millimetric hollow hydrogel spheres, encapsulating cells and coated internally with a layer of reconstituted extracellular matrix (ECM) of a few microns thick. The spherical capsules, composed of alginate hydrogel, originate from the spontaneous instability of a multi-layered jet formed by co-extrusion using a coaxial flow device. We provide a simple design to manufacture this device using a DLP (digital light processing) 3D printer. Then, we demonstrate how the inner wall of the capsules can be decorated with a continuous ECM layer that is anchored to the alginate gel and mimics the basal membrane of a cellular niche. Finally, we used this approach to encapsulate human Neural Stem Cells (hNSC) derived from human Induced Pluripotent Stem Cells (hIPSC), which were further differentiated into neurons within the capsules with negligible loss of viability. Altogether, we show that these capsules may serve as cell micro-containers compatible with complex cell culture conditions and applications. These developments widen the field of research and biomedical applications of the cell encapsulation technology. PMID:27025278

  13. Human iPSC-Derived Endothelial Cell Sprouting Assay in Synthetic Hydrogel Arrays

    Science.gov (United States)

    Activation of vascular endothelial cells (ECs) by growth factors initiates a cascade of events in vivo consisting of EC tip cell selection, sprout formation, EC stalk cell proliferation, and ultimately vascular stabilization by support cells. Although EC functional assays can rec...

  14. Self-assembling Fmoc dipeptide hydrogel for in situ 3D cell culturing

    OpenAIRE

    Akpe Victor; Rydholm Susanna; Liebmann Thomas; Brismar Hjalmar

    2007-01-01

    Abstract Background Conventional cell culture studies have been performed on 2D surfaces, resulting in flat, extended cell growth. More relevant studies are desired to better mimic 3D in vivo tissue growth. Such realistic environments should be the aim of any cell growth study, requiring new methods for culturing cells in vitro. Cell biology is also tending toward miniaturization for increased efficiency and specificity. This paper discusses the application of a self-assembling peptide-derive...

  15. A Self-Folding Hydrogel In Vitro Model for Ductal Carcinoma.

    Science.gov (United States)

    Kwag, Hye Rin; Serbo, Janna V; Korangath, Preethi; Sukumar, Saraswati; Romer, Lewis H; Gracias, David H

    2016-04-01

    A significant challenge in oncology is the need to develop in vitro models that accurately mimic the complex microenvironment within and around normal and diseased tissues. Here, we describe a self-folding approach to create curved hydrogel microstructures that more accurately mimic the geometry of ducts and acini within the mammary glands, as compared to existing three-dimensional block-like models or flat dishes. The microstructures are composed of photopatterned bilayers of poly (ethylene glycol) diacrylate (PEGDA), a hydrogel widely used in tissue engineering. The PEGDA bilayers of dissimilar molecular weights spontaneously curve when released from the underlying substrate due to differential swelling ratios. The photopatterns can be altered via AutoCAD-designed photomasks so that a variety of ductal and acinar mimetic structures can be mass-produced. In addition, by co-polymerizing methacrylated gelatin (methagel) with PEGDA, microstructures with increased cell adherence are synthesized. Biocompatibility and versatility of our approach is highlighted by culturing either SUM159 cells, which were seeded postfabrication, or MDA-MB-231 cells, which were encapsulated in hydrogels; cell viability is verified over 9 and 15 days, respectively. We believe that self-folding processes and associated tubular, curved, and folded constructs like the ones demonstrated here can facilitate the design of more accurate in vitro models for investigating ductal carcinoma. PMID:26831041

  16. 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

  17. A Supramolecular Hydrogel Inspired by Elastin

    Institute of Scientific and Technical Information of China (English)

    丁磊; 王淑芳; 武文洁; 胡月晗; 杨翠红; 谭鸣; 孔德领; 杨志谋

    2011-01-01

    Self-assembly prevails in nature and learning from nature will lead to biofunctional materials. Inspired by the protein of elastin, we reported in this study on a supramolecular hydrogel beating the elastin repeating peptide of VPGAG. The visco-elasticity property, morphology of the nanostructures, and aromatic stacking in the self-assembled nanostructure were characterized by a rheometry, transmission electron microscope (TEM), and fluorescence microscope, respectively. The biocompatibility of the gelator was also proved by an MTT assay. Though the supramolecular hydrogel failed to exhibit a high elasticity like elastin, the thixotropic hydrogel might have potentials for the applications in fields of cell culture, controlled-drug release, etc.

  18. Apoptosis of hepatoma cells SMMC-7721 induced by Ginkgo biloba seed polysaccharide

    Institute of Scientific and Technical Information of China (English)

    Qun Chen; Gui-Wen Yang; Li-Guo An

    2002-01-01

    AIM: To study the apoptosis of hepatoma cells SMMC-7721induced by polysaccharide isolated from Ginkgo biloba seed.METHODS: Ginkgo biloba seed polysaccharide (GBSP) wasisolated by ethanol fractionation of Ginkgo biloba seed andpurified by Sephadex G-200 chromatography. The purity ofGBSP was verified by reaction with iodine-potassium iodideand ninhydrin and confirmed by UV spectrophotometer,cellulose acetate membrane electrophoresis and Sepharose4B gel filtration chromatography. The Scanning ElectronMicroscope (SEM) and Flow Cytometrv (FCM) were used toexamine the SMMC-7721 cells with and without GBSPtreatment at 500 mg/ml for 36 h.RESULTS: GBSP product obtained was of high purity withthe average molecular weight of 1.86 × 105. Quantitativeanalysis of SMMC-7721 cells in vitro with FCM showed thatthe percentages of G2-M cells without and with GBSPtreatment were 17.01±1.28 % and 11.77±1.50% (P<0.05),the debds ratio of the cells were 0.46±0.12 % and 0.06±0 .06 %(P<0.01), and the apoptosis ratio of cells was 3.84±0 .55 %and 9.13±1.48 %(P<0.01) respectively. Following GBSPtreatment, microvilli of SMMC-7721 cells appeared thinnerand the number of spherical cells increased markedly. Mostsignificantly, the apoptosis bodies were formed on andaround the spherical cells treated with GBSP.CONCLUSION: GBSP could potentially induce the apoptosisof SMMC-7721 cells.

  19. Studies on the PEO-PPO-PEO Block Copolymer Release from Alginate Hydrogel

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    @@ Introduction Alginate hydrogel is one of the most widely used carriers for the immobilization of micro bial cells. If surfactants are encapsulated with alginate hydrogel, increasing temperature or concentration can make the encapsulated surfactants aggregate and form micelle.

  20. In vitro evaluation of cell-seeded chitosan films for peripheral nerve tissue engineering

    OpenAIRE

    Wrobel, Sandra; Serra, Sofia Cristina; Samy, S. M.; Sousa, Nuno; Heimann, Claudia; Barwig, Christina; Grothe, Claudia; Salgado, A. J.; Talini, Kirsten Haastert

    2014-01-01

    Natural biomaterials have attracted an increasing interest in the field of tissue-engineered nerve grafts, representing a possible alternative to autologous nerve transplantation. With the prospect of developing a novel entubulation strategy for transected nerves with cell-seeded chitosan films, we examined the biocompatibility of such films in vitro. Different types of rat Schwann cells (SCs)—immortalized, neonatal, and adult—as well as rat bone-marrow-derived mesenchymal stromal cells (BMSC...

  1. Growth Factors Polymerized Within Fibrin Hydrogel Promote Amylase Production in Parotid Cells

    OpenAIRE

    McCall, Andrew D.; Joel W. Nelson; Leigh, Noel J.; Duffey, Michael E.; Lei, Pedro; Andreadis, Stelios T.; Baker, Olga J.

    2013-01-01

    Salivary gland cell differentiation has been a recurring challenge for researchers as primary salivary cells show a loss of phenotype in culture. Particularly, parotid cells show a marked decrease in amylase expression, the loss of tight junction organization and proper cell function. Previously, Matrigel has been used successfully as an extracellular matrix; however, it is not practical for in vivo applications as it is tumorigenic. An alternative method could rely on the use of fibrin hydro...

  2. Oscillating hydrogel based bioreactors for chondrogenic differentiation of mesenchymal stem cells

    OpenAIRE

    Neiman, Veronica Juliet

    2010-01-01

    Harnessing the differentiative potential of stem cells for use in tissue repair could be a powerful therapy for debilitating diseases. However, one of the bottlenecks of stem cell based therapeutics and tissue engineering is inefficient and homogeneous stem cell differentiation. Various physico-chemical cues such as mechanical strain, chemical components, and soluble factors have been shown to direct stem cell differentiation. This study developed a multifunctional polymer-based artificial EC...

  3. Preparation, characterization and protein sorption of photo-crosslinked cell membrane-mimicking chitosan-based hydrogels.

    Science.gov (United States)

    Zhao, Yunfei; Ma, Liubo; Zeng, Rong; Tu, Mei; Zhao, Jianhao

    2016-10-20

    Photocrosslinkable biomimetic chitosan derivative, glycidyl methacrylate-phosphorylcholine-chitosan (PCCs-GMA) was synthesized through the combination of Atherton-Todd reaction for coupling phosphorylcholine and ring opening reaction of epoxides for attaching GMA, and confirmed by (1)H and (31)P NMR and Fourier transform infrared (FTIR) spectroscopy. The photo-crosslinking reaction of PCCs-GMA with different degree of substitution (DS) of GMA allowed the formation of biomimetic hydrogels with tunable mechanical and swelling properties. Cold crystallization behaviors ascribed to their restrained freezing bound water were investigated using differential scanning calorimetry (DSC). The rheological and swelling behaviors, hemolysis as well as protein sorption of PCCs-GMA hydrogels were investigated in terms of the DS of GMA, using fibrinogen, bovine serum albumin and lysozyme as model proteins. Low irreversible protein sorption and non hemolytic results indicated that photo-crosslinked PCCs-GMA hydrogels may offer a promising candidate material with resistance to protein fouling in biomedical applications. PMID:27474563

  4. Human adipose-derived stromal cells in a clinically applicable injectable alginate hydrogel

    DEFF Research Database (Denmark)

    Larsen, Bjarke Follin; Juhl, Morten; Cohen, Smadar;

    2015-01-01

    BACKGROUND AIMS: Clinical trials have documented beneficial effects of mesenchymal stromal cells from bone marrow and adipose tissue (ASCs) as treatment in patients with ischemic heart disease. However, retention of transplanted cells is poor. One potential way to increase cell retention is to in...... and alginate is non-immunogenic and, in fact, immunosuppressive....

  5. Anticancer activity of Petroselinum sativum seed extracts on MCF-7 human breast cancer cells.

    Science.gov (United States)

    Farshori, Nida Nayyar; Al-Sheddi, Ebtesam Saad; Al-Oqail, Mai Mohammad; Musarrat, Javed; Al-Khedhairy, Abdulaziz Ali; Siddiqui, Maqsood Ahmed

    2013-01-01

    Pharmacological and preventive properties of Petroselinum sativum seed extracts are well known, but the anticancer activity of alcoholic extracts and oil of Petroselinum sativum seeds on human breast cancer cells have not been explored so far. Therefore, the present study was designed to investigate the cytotoxic activities of these extracts against MCF-7 cells. Cells were exposed to 10 to 1000 μg/ml of alcoholic seed extract (PSA) and seed oil (PSO) of Petroselinum sativum for 24 h. Post-treatment, percent cell viability was studied by 3-(4, 5-dimethylthiazol-2yl)-2, 5-biphenyl tetrazolium bromide (MTT) and neutral red uptake (NRU) assays, and cellular morphology by phase contrast inverted microscopy. The results showed that PSA and PSO significantly reduced cell viability, and altered the cellular morphology of MCF-7 cells in a concentration dependent manner. Concentrations of 50 μg/ml and above of PSA and 100 μg/ml and above of PSO were found to be cytotoxic in MCF-7 cells. Cell viability at 50, 100, 250, 500 and 1000 μg/ml of PSA was recorded as 81%, 57%, 33%, 8% and 5%, respectively, whereas at 100, 250, 500, and 1000 μg/ml of PSO values were 90%, 78%, 62%, and 8%, respectively by MTT assay. MCF-7 cells exposed to 250, 500 and 1000 μg/ml of PSA and PSO lost their typical morphology and appeared smaller in size. The data revealed that the treatment with PSA and PSO of Petroselinum sativum induced cell death in MCF-7 cells. PMID:24289568

  6. Nanostructuring PEG-fibrinogen hydrogels to control cellular morphogenesis.

    Science.gov (United States)

    Frisman, Ilya; Seliktar, Dror; Bianco-Peled, Havazelet

    2011-11-01

    The nanostructuring of hydrogel scaffolds used in tissue engineering aims to provide an ability to control cellular morphogenesis through defined cell-matrix interactions. Toward this objective, we developed a method that alters the molecular network structure of biosynthetic hydrogel scaffolds made from crosslinked poly(ethylene glycol)-fibrinogen conjugates (PEG-fibrinogen, PF). The modifications were based on Pluronic(®) F127 micelles that were formed in the hydrogel precursor solution and that altered the hydrogel network assembly during photopolymerization crosslinking. Two variations of the cell-encapsulating hydrogels (high and low crosslinking density) were prepared with three concentrations of Pluronic(®) F127 (3%, 7%, 10% w/v). Quantitative morphometrics were used to characterize fibroblast shape parameters (both transient and stable) in all hydrogels, and rheological characterizations were used to measure the elastic (storage) component of the complex shear modulus of these hydrogels. The morphometric data was then correlated to both the nanostructure and modulus of the hydrogels for day 1 and day 4 in culture. These correlations revealed that structural features imparted by the Pluronic(®) F127 micelles were able to reverse the normally strong correlations found between indicators of cell spreading and the hydrogel's mechanical properties. Therefore, the data supports the conclusion that nanostructural features in the encapsulating hydrogel culture environment can facilitate better cell spreading in a dense hydrogel milieu, simply by introducing imperfections into the network structure. This research also provides further prospective regarding biocompatible approaches toward making structural modifications to hydrogel scaffolds for the purpose of 3-D cell culture and tissue engineering. PMID:21784517

  7. A soap technique for cell separation to study the seed coat of Sesbania punicea.

    Science.gov (United States)

    Bevilacqua, L; Massa, G; Modenesi, P; Fossati, F

    1993-05-01

    A technique is described for separating plant cells used for morphological studies. The plant material is placed in a concentrated solution of olive oil castile soap for 1-2 days or more. The material is then thoroughly washed and placed between two glass slides. The upper glass slide is lifted from the lower one, then gently pressed down several times. Through this procedure Malpighian cells of the seed coat of Sesbania punicea, mesophyll cells of Euphorbia peplus and of Trifolium pratense and cortical cells of the aerial roots of Monstera deliciosa have been separated. Various shapes of the Malpighian cells of the Sesbania punicea seed coat can be observed along with intermediates. PMID:7687883

  8. Development of Hydrophobized Alginate Hydrogels for the Vessel-Simulating Flow-Through Cell and Their Usage for Biorelevant Drug-Eluting Stent Testing

    OpenAIRE

    Semmling, Beatrice; Nagel, Stefan; Sternberg, Katrin; Weitschies, Werner; Seidlitz, Anne

    2013-01-01

    The vessel-simulating flow-through cell (vFTC) has been used to examine release and distribution from drug-eluting stents in an in vitro model adapted to the stent placement in vivo. The aim of this study was to examine the effect of the admixture of different hydrophobic additives to the vessel wall simulating hydrogel compartment on release and distribution from model substance-coated stents. Four alginate-based gel formulations containing reversed-phase column microparticles LiChroprep® RP...

  9. Facile preparation of photodegradable hydrogels by photopolymerization

    OpenAIRE

    Ki, Chang Seok; Shih, Han; Lin, Chien-Chi

    2013-01-01

    Photodegradable hydrogels have emerged as a powerful material platform for studying and directing cell behaviors, as well as for delivering drugs. The premise of this technique is to use a cytocompatible light source to cleave linkers within a hydrogel, thus causing reduction of matrix stiffness or liberation of matrix-tethered biomolecules in a spatial-temporally controlled manner. The most commonly used photodegradable units are molecules containing nitrobenzyl moieties that absorb light in...

  10. Apoptosis-inducing effects of jujube (Zǎo) seed extracts on human Jurkat leukemia T cells

    OpenAIRE

    Taechakulwanijya, Natthanan; Weerapreeyakul, Natthida; Barusrux, Sahapat; Siriamornpun, Sirithorn

    2016-01-01

    Background Jujube (Zǎo) seeds exhibited anticancer effects and used in Chinese medicine for many years. This study aims to investigate the apoptosis-inducing effects of seed extracts from eight different cultivated species (‘Apple’, ‘Bombay’, ‘Jumbo’, ‘Kaew’, ‘Nomsod’, ‘Rianthong’, ‘Samros’, and ‘Taiwan’) on human Jurkat leukemia T cells. Methods We evaluated the effects of seed extracts from eight jujube cultivated species on human Jurkat leukemia T cells. The crude seed extracts were prepar...

  11. Cartilage constructs from human cord blood stem cells seeded in structurally-graded polycaprolactone scaffolds

    DEFF Research Database (Denmark)

    Munir, Samir; Koch, Thomas Gadegaard; Foldager, Casper Bindzus;

    stimulation. This study demonstrated the chondrogenic potential of human cord blood-derived Multi-Lineage Progenitor Cells (MLPCs) under normoxic and hypoxic culture conditions. Second, MLPCs were seeded in a novel, structurally graded polycaprolactone (SGS-PCL) scaffold and chondrogenesis was evaluated...

  12. Micropatterned 3-Dimensional Hydrogel System to Study Human Endothelial-Mesenchymal Stem Cell Interactions

    OpenAIRE

    Trkov, Sasa; Eng, George; Di Liddo, Rosa; Parnigotto, Pier Paolo; Vunjak-Novakovic, Gordana

    2010-01-01

    The creation of vascularized engineered tissues of clinically relevant size is a major challenge of tissue engineering. While it is known that endothelial and mural vascular cells are integral to the formation of stable blood vessels, the specific cell type and optimal conditions for engineered vascular networks are poorly understood. To this end, we investigated the vasculogenic potential of human mesenchymal stem cell (MSC) populations derived from three different sources: (i) bone marrow a...

  13. Horseradish peroxidase/catalase-mediated cell-laden alginate-based hydrogel tube production in two-phase coaxial flow of aqueous solutions for filament-like tissues fabrication

    International Nuclear Information System (INIS)

    We report a method for preparing cell-laden hydrogel tubes. This method uses a coaxial double-orifice spinneret, simpler than triple-orifice spinnerets which have been used for preparing similar constructs. The intended application was to create a template for preparing filament-like structures composed of two heterogeneous living cell layers. An aqueous solution containing an alginate derivative possessing phenolic hydroxyl moieties (Alg-Ph), catalase and horseradish peroxidase (HRP) was extruded into an ambient flow of H2O2 aqueous solution. This operation enabled the Alg-Ph solution to be gellable through a HRP-catalyzed reaction, cross-linking the Ph moieties together. By altering flow rates of the Alg-Ph and H2O2 solutions along with the concentrations of catalase and H2O2, the diameter and membrane thickness of the hydrogel tubes were controllable between 250–550 µm and 70–140 µm, respectively. The viability of the HeLa cells enclosed in the hydrogel tubes with a diameter of 300 µm and a membrane thickness of 80 µm was 95.4%. Subsequently, the enclosed HeLa cells grew and filled the hollow core. A filament-like structure of HeLa cells covered with a layer of fibroblast 10T1/2 cells was obtained when confluency of fibroblast 10T1/2 cells was reached and the hydrogel matrix was degraded with alginate lyase. (paper)

  14. Fabrication of dye-sensitized solar cell (DSSC) using annato seeds (Bixa orellana Linn)

    International Nuclear Information System (INIS)

    The Fabrication of dye sensitized solar cell (DSSC) using Annato seeds has been conducted in this study. Annato seeds (Bixa orellana Linn) used as a sensitizer for dye sensitized solar cell. The experimental parameter was concentration of natural dye. Annato seeds was extracted using etanol solution and the concentration was controlled by varying mass of Annato seeds. A semiconductor TiO2 was prepared by a screen printing method for coating glass use paste of TiO2. Construction DSSC used layered systems (sandwich) consists of working electrode (TiO2 semiconductor-dye) and counter electrode (platina). Both are placed on conductive glass and electrolytes that occur electrons cycle. The characterization of thin layer of TiO2 was conducted using SEM (Scanning Electron Microscpy) analysis showed the surface morphology of TiO2 thin layer and the cross section of a thin layer of TiO2 with a thickness of 15–19 μm. Characterization of natural dye extract was determined using UV-Vis spectrometry analysis shows the wavelength range annato seeds is 328–515 nm, and the voltage (Voc) and electric current (Isc) resulted in keithley test for 30 gram, 40 gram, and 50 gram were 0,4000 V; 0,4251 V; 0,4502 V and 0,000074 A; 0,000458 A; 0,000857 A, respectively. The efficiencies of the fabricated solar cells using annato seeds as senstizer for each varying mass are 0,00799%, 0,01237%, and 0,05696%

  15. Memory T-cell competition for bone marrow seeding.

    Science.gov (United States)

    Di Rosa, Francesca; Santoni, Angela

    2003-03-01

    The presence in the bone marrow of memory CD8 T cells is well recognized. However, it is still largely unclear how T-cell migration from the lymphoid periphery to the bone marrow is regulated. In the present report, we show that antigen-specific CD4 T cells, as well as antigen-specific CD8 T cells, localize to the bone marrow of immunized mice, and are sustained there over long periods of time. To investigate the rules governing T-cell migration to the bone marrow, we generated chimeric mice in which the lymphoid periphery contained two genetically or phenotypically distinct groups of T cells, one of which was identical to the host. We then examined whether a distinct type of T cell had an advantage over the others in the colonization of bone marrow. Our results show that whereas ICAM1 and CD18 molecules are both involved in homing to lymph nodes, neither is crucial for T-cell bone marrow colonization. We also observed that memory-phenotype CD44high T cells, but not virgin-type CD44-/low T cells, preferentially home to the bone marrow upon adoptive transfer to normal young mice, but not to thymectomized old recipients where an existing memory T-cell pool precludes their free access. Thus, T-cell colonization of the bone marrow uses distinct molecules from those implicated in lymph node homing, and is regulated both by the properties of the T cell and by the competitive efficacy of other T cells inhabiting the same, saturable niche. This implies that the homing potential of an individual lymphocyte is not merely an intrinsic property of the cell, but rather a property of the lymphoid system taken as a whole. PMID:12603595

  16. Stress-stiffening-mediated stem-cell commitment switch in soft responsive hydrogels

    Science.gov (United States)

    Das, Rajat K.; Gocheva, Veronika; Hammink, Roel; Zouani, Omar F.; Rowan, Alan E.

    2016-03-01

    Bulk matrix stiffness has emerged as a key mechanical cue in stem cell differentiation. Here, we show that the commitment and differentiation of human mesenchymal stem cells encapsulated in physiologically soft (~0.2-0.4 kPa), fully synthetic polyisocyanopeptide-based three-dimensional (3D) matrices that mimic the stiffness of adult stem cell niches and show biopolymer-like stress stiffening, can be readily switched from adipogenesis to osteogenesis by changing only the onset of stress stiffening. This mechanical behaviour can be tuned by simply altering the material’s polymer length whilst maintaining stiffness and ligand density. Our findings introduce stress stiffening as an important parameter that governs stem cell fate in a 3D microenvironment, and reveal a correlation between the onset of stiffening and the expression of the microtubule-associated protein DCAMKL1, thus implicating DCAMKL1 in a stress-stiffening-mediated, mechanotransduction pathway that involves microtubule dynamics in stem cell osteogenesis.

  17. Ectopic bone formation using an injectable biphasic calcium phosphate/Si-HPMC hydrogel composite loaded with undifferentiated bone marrow stromal cells.

    Science.gov (United States)

    Trojani, Christophe; Boukhechba, Florian; Scimeca, Jean-Claude; Vandenbos, Fanny; Michiels, Jean-François; Daculsi, Guy; Boileau, Pascal; Weiss, Pierre; Carle, Georges F; Rochet, Nathalie

    2006-06-01

    We have used a new synthetic injectable composite constituted of hydroxyapatite/tricalcium phosphate (HA/TCP) particles in suspension in a self-hardening Si-hydroxypropylmethylcellulose (HPMC) hydrogel. The aim of this study was to evaluate in vivo the biocompatibility and the new bone formation efficacy of this scaffold loaded with undifferentiated bone marrow stromal cells (BMSCs). This biomaterial was mixed extemporaneously with BMSCs prepared from C57BL/6 mice, injected in subcutaneous and intramuscular sites and retrieved 4 and 8 weeks after implantation. Dissection of the implants revealed a hard consistency and the absence of a fibrous capsule reflecting a good integration into the host tissues. Histological analysis showed mineralized woven bone in the granule inter-space with numerous active osteoclasts attached to the particles as assessed by the presence of multinucleated cells positively stained for TRAP activity and for the a3 subunit of the V-ATPase. Small vessels were homogenously distributed in the whole implants. Similar results were obtained in SC and IM sites and no bone formation was observed in the control groups when cell-free and particle-free transplants were injected. These results indicate that this injectable biphasic calcium phosphate-hydrogel composite mixed with undifferentiated BMSCs is a new promising osteoinductive bone substitute. It also provides with an original in vivo model of osteoclast differentiation and function. PMID:16510180

  18. Macroporous 2-hydroxyethyl methacrylate hydrogels of dual porosity for cell cultivation: morphology, swelling, permeability, and mechanical behavior

    Czech Academy of Sciences Publication Activity Database

    Přádný, Martin; Dušková-Smrčková, Miroslava; Dušek, Karel; Janoušková, Olga; Sadakbayeva, Zhansaya; Šlouf, Miroslav; Michálek, Jiří

    2014-01-01

    Roč. 21, č. 11 (2014), 579_1-579_12. ISSN 1022-9760 R&D Projects: GA ČR GAP108/12/1538 Institutional support: RVO:61389013 Keywords : hydrogel * 2-hydroxyethyl methacrylate * porosity Subject RIV: CD - Macromolecular Chemistry Impact factor: 1.920, year: 2014

  19. The design of reversible hydrogels to capture extracellular matrix dynamics

    Science.gov (United States)

    Rosales, Adrianne M.; Anseth, Kristi S.

    2016-02-01

    The extracellular matrix (ECM) is a dynamic environment that constantly provides physical and chemical cues to embedded cells. Much progress has been made in engineering hydrogels that can mimic the ECM, but hydrogel properties are, in general, static. To recapitulate the dynamic nature of the ECM, many reversible chemistries have been incorporated into hydrogels to regulate cell spreading, biochemical ligand presentation and matrix mechanics. For example, emerging trends include the use of molecular photoswitches or biomolecule hybridization to control polymer chain conformation, thereby enabling the modulation of the hydrogel between two states on demand. In addition, many non-covalent, dynamic chemical bonds have found increasing use as hydrogel crosslinkers or tethers for cell signalling molecules. These reversible chemistries will provide greater temporal control of adhered cell behaviour, and they allow for more advanced in vitro models and tissue-engineering scaffolds to direct cell fate.

  20. Inhibitory effects of guarana seed extract on passive cutaneous anaphylaxis and mast cell degranulation.

    Science.gov (United States)

    Jippo, Tomoko; Kobayashi, Yuko; Sato, Harumi; Hattori, Atsushi; Takeuchi, Hiroaki; Sugimoto, Keiichiro; Shigekawa, Munekazu

    2009-09-01

    This study investigated the effects of guarana seed extract (GSE) on an anti-allergic mechanism. GSE orally administered inhibited the anti-dinitrophenol IgE-induced passive cutaneous anaphylaxis reaction in mice. Furthermore, it inhibited the degranulation of rat basophilic leukemia RBL-2H3 cells. It had no cytotoxicity on RBL-2H3 cells. These results show that GSE is a candidate for effective therapeutic material for allergic diseases. PMID:19734657

  1. Promoting Cell Survival and Proliferation in Degradable Poly(vinyl alcohol)-Tyramine Hydrogels.

    Science.gov (United States)

    Lim, Khoon S; Ramaswamy, Yogambha; Roberts, Justine J; Alves, Marie-Helene; Poole-Warren, Laura A; Martens, Penny J

    2015-10-01

    A photopolymerizable-tyraminated poly(vinyl alcohol) (PVA-Tyr) system that has the ability to covalently bind proteins in their native state was evaluated as a platform for cell encapsulation. However, a key hurdle to this system is the radicals generated during the cross-linking that can cause oxidative stress to the cells. This research hypothesized that incorporation of anti-oxidative proteins (sericin and gelatin) into PVA-Tyr gels would mitigate any toxicity caused by the radicals. The results showed that although incorporation of 1 wt% sericin promoted survival of the fibroblasts, both sericin and gelatin acted synergistically to facilitate long-term 3D cell function. The encapsulated cells formed clusters with deposition of laminin and collagen, as well as remaining metabolically active after 21 d. PMID:26097045

  2. Optimization of Seeding Density in Microencapsulated Recombinant CHO Cell Culture

    OpenAIRE

    Zhang, Ying; Zhou, Jing; Zhang, Xulang; Yu, Weiting; Guo, Xin; Wang, Wei; Ma, Xiaojun

    2008-01-01

    Microencapsulation technology is an alternative large-scale mammalian cell culture method. The semi-permeable membrane of the microcapsule allows free diffusion of nutrients, oxygen and toxic metabolites to support cell growth, and the microcapsule membrane can protect the cells from the mechanical damage of shear forces associated with agitation and aeration. Many polymers have been used to make microcapsules, such as chitosan, polyacrylates, alginate, polyamino acids, and polyamides. One of...

  3. Cell Migration on Planar and Three-Dimensional Matrices: A Hydrogel-Based Perspective

    OpenAIRE

    Vu, Lucas T.; Jain, Gaurav; Veres, Brandon D.; Rajagopalan, Padmavathy

    2014-01-01

    The migration of cells is a complex process that is dependent on the properties of the surrounding environment. In vivo, the extracellular environment is complex with a wide range of physical features, topographies, and protein compositions. There have been a number of approaches to design substrates that can recapitulate the complex architecture in vivo. Two-dimensional (2D) substrates have been widely used to study the effect of material properties on cell migration. However, such substrate...

  4. A composite hydrogel platform for the dissection of tumor cell migration at tissue interfaces

    OpenAIRE

    Rape, AD; Kumar, S.

    2014-01-01

    Glioblastoma multiforme (GBM), the most prevalent primary brain cancer, is characterized by diffuse infiltration of tumor cells into brain tissue, which severely complicates surgical resection and contributes to tumor recurrence. The most rapid mode of tissue infiltration occurs along blood vessels or white matter tracts, which represent topological interfaces thought to serve as "tracks" that speed cell migration. Despite this observation, the field lacks experimental paradigms that capture ...

  5. Assessment of Lemon Balm (Melissa officinalis L. Hydrogels: Quality and Bioactivity in Skin Cells

    Directory of Open Access Journals (Sweden)

    Kristina Ramanauskienė

    2015-01-01

    Full Text Available The aim of the study was to design gels with lemon balm extract, assess their quality, and investigate the effect of rosmarinic acid on skin cells in normal conditions and under oxidative stress. Methods. The quantities of rosmarinic acid (RA released from gels were evaluated by applying the HPLC technique. HaCaT cell viability was assessed by using the MTT method. ROS generation was measured using DCFH-DA dye. The results showed that the gelling material affected the release of RA content from gels. Lower and slower RA content release was determined in carbomer-based gels. After 6 hours of biopharmaceutical research in vitro, at least 4% of RA was released from the gel. The results of the biological studies on HaCaT cells demonstrated that, in the oxidative stress conditions, RA reduced intracellular ROS amounts to 28%; 0.25–0.5 mg/mL of RA increased cell viability by 10–24% and protected cells from the damage caused by H2O2. Conclusions. According to research results, it is appropriate to use a carbomer as the main gelling material, and its concentration should not exceed 1.0%. RA, depending on the concentration, reduces the amount of intracellular ROS and enhances cell viability in human keratinocytes in oxidative stress conditions.

  6. Study on apoptosis of prostate cancer cell induced by 125I seed irradiation

    International Nuclear Information System (INIS)

    Objective: To explore the mechanism of apoptosis induced by 125I seed irradiation on PC3 cells. Methods: Human prostate cancer cell line PC3 was treated by irradiation of 125I (2.77 cGy/h) with various dose. Agarose gel electrophoresis of DNA and flows cytometry were used to detect the apoptosis of PC3 cells and indirect immunofluorescence assay was used to detect the expression of Bcl-2. The activity of Caspase-3 was measured by Caspase Colorimetric Assay Kits. Results: Apoptosis of PC3 cells could be efficiently induced by 125I seed irradiation. The apoptotic peaks were found by flow cytometry and DNA ladder appeared on 1.8% agarose gel. The activity of Caspase-3 on PC3 cells treated by 125I seed irradiation was not changed significantly. Bcl-2 gene expression was down-regulated with the sample concentration increased. Conclusion: 125I irradiation can induce the apoptosis of PC3 cells and the mechanism of apoptosis is related with down regulation of Bcl-2 gene expression and is not related with Caspase-3 activity. (authors)

  7. Induced Pluripotent Stem Cell-derived Mesenchymal Stem Cell Seeding on Biofunctionalized Calcium Phosphate Cements

    Institute of Scientific and Technical Information of China (English)

    WahWah TheinHan; Jun Liu; Minghui Tang; Wenchuan Chen; Linzhao Cheng; Hockin H. K. Xu

    2013-01-01

    Induced pluripotent stem cells (iPSCs) have great potential due to their proliferation and differentiation capability. The objectives of this study were to generate iPSC-derived mesenchymal stem cells (iPSC-MSCs), and investigate iPSC-MSC proliferation and osteogenic differentiation on calcium phosphate cement (CPC) containing biofunctional agents for the first time. Human iPSCs were derived from marrow CD34+ cells which were reprogrammed by a single episomal vector. iPSCs were cultured to form embryoid bodies (EBs), and MSCs migrated out of EBs. Five biofunctional agents were incorporated into CPC:RGD (Arg-Gly-Asp) peptides, fibronectin (Fn), fibronectin-like engineered polymer protein (FEPP), extracellular matrix Geltrex, and platelet concentrate. iPSC-MSCs were seeded on five biofunctionalized CPCs:CPC-RGD, CPC-Fn, CPC-FEPP, CPC-Geltrex, and CPC-Platelets. iPSC-MSCs on biofunctional CPCs had enhanced proliferation, actin fiber expression, osteogenic differentiation and mineralization, compared to control. Cell proliferation was greatly increased on biofunctional CPCs. iPSC-MSCs underwent osteogenic differentiation with increased alkaline phosphatase, Runx2 and collagen-I expressions. Mineral synthesis by iPSC-MSCs on CPC-Platelets was 3-fold that of CPC control. In conclusion, iPSCs showed high potential for bone engineering. iPSC-MSCs on biofunctionalized CPCs had cell proliferation and bone mineralization that were much better than traditional CPC. iPSC-MSC-CPC constructs are promising to promote bone regeneration in craniofacial/orthopedic repairs.

  8. Immobilization of yeast cells with ionic hydrogel produced by radiation polymerization

    International Nuclear Information System (INIS)

    The mixture of an ionic monomer of 2-acrylamido 2-methylpropane-sulfonic acid and a series of polyethylene glycol dimethacrylate monomer were polymerized at-78 deg C with 60Co γ-rays and were used for immobilization of yeast cells. The immobilized yeast cells with these carriers had higher ethanol productivity than that without any carriers. The yield of ethanol with poly TBAS-14G carrier was the highest, and increased by 3.5 times compared with the free yeast cells. It was found that the ethanol yield increased with the increase of the glycol number in polyethylene glycol dimethacrylate. The state of the immobilized cells was observed with microscope and it was found that the difference in the ethanol productivity was mainly due to the difference in the internal structure and the properties of polymer carrier. It was considered that the polymer carrier had a proper hydrophilicity, swelling ability, cation in the surface and porousity in the internal structure for immobilizing yeast cells

  9. Biodegradable Cell-Seeded Nanofiber Scaffolds for Neural Repair

    Directory of Open Access Journals (Sweden)

    Karen C. Cheung

    2011-10-01

    Full Text Available Central and peripheral neural injuries are traumatic and can lead to loss of motor and sensory function, chronic pain, and permanent disability. Strategies that bridge the site of injury and allow axonal regeneration promise to have a large impact on restoring quality of life for these patients. Engineered materials can be used to guide axonal growth. Specifically, nanofiber structures can mimic the natural extracellular matrix, and aligned nanofibers have been shown to direct neurite outgrowth and support axon regeneration. In addition, cell-seeded scaffolds can assist in the remyelination of the regenerating axons. The electrospinning process allows control over fiber diameter, alignment, porosity, and morphology. Biodegradable polymers have been electrospun and their use in tissue engineering has been demonstrated. This paper discusses aspects of electrospun biodegradable nanofibers for neural regeneration, how fiber alignment affects cell alignment, and how cell-seeded scaffolds can increase the effectiveness of such implants.

  10. Dye-sensitized solar cells with natural dyes extracted from plant seeds

    Science.gov (United States)

    El-Ghamri, Hatem S.; El-Agez, Taher M.; Taya, Sofyan A.; Abdel-Latif, Monzir S.; Batniji, Amal Y.

    2014-12-01

    The application of natural dyes extracted from plant seeds in the fabrication of dye-sensitized solar cells (DSSCs) has been explored. Ten dyes were extracted from different plant seeds and used as sensitizers for DSSCs. The dyes were characterized using UV-Vis spectrophotometry. DSSCs were prepared using TiO2 and ZnO nanostructured mesoporous films. The highest conversion efficiency of 0.875 % was obtained with an allium cepa (onion) extract-sensitized TiO2 solar cell. The process of TiO2-film sintering was studied and it was found that the sintering procedure significantly affects the response of the cell. The short circuit current of the DSSC was found to be considerably enhanced when the TiO2 semiconducting layer was sintered gradually.

  11. A composite hydrogel platform for the dissection of tumor cell migration at tissue interfaces.

    Science.gov (United States)

    Rape, Andrew D; Kumar, Sanjay

    2014-10-01

    Glioblastoma multiforme (GBM), the most prevalent primary brain cancer, is characterized by diffuse infiltration of tumor cells into brain tissue, which severely complicates surgical resection and contributes to tumor recurrence. The most rapid mode of tissue infiltration occurs along blood vessels or white matter tracts, which represent topological interfaces thought to serve as "tracks" that speed cell migration. Despite this observation, the field lacks experimental paradigms that capture key features of these tissue interfaces and allow reductionist dissection of mechanisms of this interfacial motility. To address this need, we developed a culture system in which tumor cells are sandwiched between a fibronectin-coated ventral surface representing vascular basement membrane and a dorsal hyaluronic acid (HA) surface representing brain parenchyma. We find that inclusion of the dorsal HA surface induces formation of adhesive complexes and significantly slows cell migration relative to a free fibronectin-coated surface. This retardation is amplified by inclusion of integrin binding peptides in the dorsal layer and expression of CD44, suggesting that the dorsal surface slows migration through biochemically specific mechanisms rather than simple steric hindrance. Moreover, both the reduction in migration speed and assembly of dorsal adhesions depend on myosin activation and the stiffness of the ventral layer, implying that mechanochemical feedback directed by the ventral layer can influence adhesive signaling at the dorsal surface. PMID:25047626

  12. Stem Cells and Hydrogel Bridges for the Treatment of Acute and Chronic Spinal Cord Injury

    Czech Academy of Sciences Publication Activity Database

    Syková, Eva; Jendelová, Pavla; Hejčl, Aleš; Kozubenko, Nataliya; Amemori, Takashi

    Roč. 19, č. 3 (366), s. 366. ISSN 0963-6897. [Annual Meeting of the American-Society-for-Neural-Therapy-and-Repair /17./. 29.04.2010-01.05.2010, Clearwater Beach] Institutional research plan: CEZ:AV0Z50390703 Keywords : stem cells * tissue engineering Subject RIV: FH - Neurology

  13. Physically crosslinked-sacran hydrogel films for wound dressing application.

    Science.gov (United States)

    Wathoni, Nasrul; Motoyama, Keiichi; Higashi, Taishi; Okajima, Maiko; Kaneko, Tatsuo; Arima, Hidetoshi

    2016-08-01

    The thin hydrogel films consisting of water-swollen polymer networks can potentially be applied for biomedical fields. Recently, natural polysaccharides have great attentions to be developed as wound healing and protection. In the present study, we newly prepared and characterized a physically crosslinked-hydrogel film composed of a novel megamolecular polysaccharide sacran for wound dressing application. We successfully fabricated a physically crosslinked-sacran hydrogel film by a solvent-casting method. The thickness of a sacran hydrogel film was lower than that of a sodium alginate (Na-alginate) film. Importantly, the swollen ratio of a sacran hydrogel film in water at 24h was 19-fold, compared to initial weight. Meanwhile, a Na-alginate hydrogel film was completely broken apart after rehydration. Moreover, a sacran hydrogel film did not show any cytotoxicity on NIH3T3 cells, a murine fibroblast cell line. The in vivo skin hydration study revealed that a sacran hydrogel film significantly increased the moisture content on hairless mice skin and considerably improved wound healing ability, compared to control (non-treated), probably due to not only the moisturing effect but also the anti-inflammatory effect of sacran. These results suggest that sacran has the potential properties as a basic biomaterial in a hydrogel film for wound dressing application. PMID:27151668

  14. Microemulsion-based hydrogel formulation for transdermal delivery of dexamethasone

    Directory of Open Access Journals (Sweden)

    Chandra Amrish

    2009-01-01

    Full Text Available The purpose of this study was to construct a microemulsion-based hydrogel formulation for the transdermal delivery of dexamethasone. Almond oil, olive oil, linseed oil, and nutmeg oil were screened as the oil phase. A microemulsion-based system was chosen due to its good solubilizing capacity and skin permeation capabilities. The pseudoternary phase diagrams for microemulsion regions were constructed using various oils, egg lecithin as the surfactant, isopropyl alcohol (IPA as the cosurfactant, and distilled water as the aqueous phase. Microemulsion gel formulations were prepared using Carbopol and filled into a reservoir-type transdermal system. The ability of various microemulsion formulations to deliver dexamethasone through the rat skin was evaluated in vitro using Keshary Chien diffusion cells. In order to enhance permeation, the skin was treated with an abrading gel (apricot seed powder in hydrogel base. The in vitro permeation data showed that microemulsions increased the permeation rate of dexamethasone compared with the control. The optimum formulation consisting of 0.1% dexamethasone, 10% olive oil, 70% egg lecithin:IPA (2:1, and water showed a permeation rate of 54.9 µg/cm 2 /h. The studied microemulsion-based hydrogel was stable toward centrifugation test and was nonirritating to the skin. The pharmacodynamic studies indicated that microemulsion based on nutmeg oil demonstrated a significantly ( P < 0.05 higher anti-inflammatory potential. The nutmeg oil-based transdermal microemulsion gel system demonstrated 73.6% inhibition in rat paw edema. Thus, microemulsion-based transdermal systems are a promising formulation for dermal delivery of dexamethasone.

  15. Antianaphylactic and mast cell stabilization activity of Strychnos potatorum Linn. seed

    Directory of Open Access Journals (Sweden)

    Umesh Jayantarao Patil

    2011-01-01

    Full Text Available Aim: The antianaphylactic activity of Strychnos potatorum Linn seed extract was evaluated by using compound 48/80 induced anaphylaxis and mast cell stabilization was studied by using peritoneal mast cells of rats. The possible antianaphylactic and mast cell stabilization mechanism was evaluated by using compound 48/80 induced mast cell activation and level of nitric oxide in rat peritoneal mast cells. Materials and Methods: Anaphylactic shock in mice was induced by the intraperitoneal administration of 8 mg/kg compound 48/80, prior to induction of anaphylaxis the animals were treated with S. potatorum Linn. seed extract administered orally 1 h before administration of compound 48/80, the rate mortality was observed in each group of animals. Mast cell stabilization was seen by preincubation of mast cells with the compound 48/80 and the extracts. Results: This study indicates that the chloroform, petroleum ether, and methanolic extracts were shown potent and has significant (P < 0.01 and P < 0.001 inhibitory effects on compound 48/80 induced anaphylactic reaction and mast cell activation. This compound also inhibited significantly compound 48/80 induced increased level of nitric oxide in rat peritoneal mast cells. Conclusion: We conclude from this study that the different extracts of S. potatorum seed have potent antianaphylactic activity through mast cell stabilization and inhibition of nitric oxide synthesis. The inhibitory effect of S. potatorum Linn. on release of histamine and nitric oxide protects from compound 48/80 induced anaphylactic reaction may be through blocking vasodilatation, decrease vascular resistance, hypotension and tachycardia induced by immunogenic agent used in this study.

  16. Percutaneous Cell Delivery Into the Heart Using Hydrogels Polymerizing In Situ

    OpenAIRE

    Martens, Timothy P.; Godier, Amandine F. G.; Parks, Jonathan J.; Wan, Leo Q.; Koeckert, Michael S; Eng, George M.; Hudson, Barry I.; Sherman, Warren; Vunjak-Novakovic, Gordana

    2009-01-01

    Heart disease is the leading cause of death in the US. Following an acute myocardial infarction, a fibrous, noncontractile scar develops, and results in congestive heart failure in more than 500,000 patients in the US each year. Muscle regeneration and the induction of new vascular growth to treat ischemic disorders of the heart can have significant therapeutic implications. Early studies in patients with chronic ischemic SLVD using skeletal myoblasts or bone marrow-derived cells report impro...

  17. QHREDGS Enhances Tube Formation, Metabolism and Survival of Endothelial Cells in Collagen-Chitosan Hydrogels

    OpenAIRE

    Miklas, Jason W.; Dallabrida, Susan M.; Reis, Lewis A.; Nesreen Ismail; Maria Rupnick; Milica Radisic

    2013-01-01

    Cell survival in complex, vascularized tissues, has been implicated as a major bottleneck in advancement of therapies based on cardiac tissue engineering. This limitation motivates the search for small, inexpensive molecules that would simultaneously be cardio-protective and vasculogenic. Here, we present peptide sequence QHREDGS, based upon the fibrinogen-like domain of angiopoietin-1, as a prime candidate molecule. We demonstrated previously that QHREDGS improved cardiomyocyte metabolism an...

  18. Boron nitride nanotube-mediated stimulation of cell co-culture on micro-engineered hydrogels.

    Directory of Open Access Journals (Sweden)

    Leonardo Ricotti

    Full Text Available In this paper, we describe the effects of the combination of topographical, mechanical, chemical and intracellular electrical stimuli on a co-culture of fibroblasts and skeletal muscle cells. The co-culture was anisotropically grown onto an engineered micro-grooved (10 µm-wide grooves polyacrylamide substrate, showing a precisely tuned Young's modulus (∼ 14 kPa and a small thickness (∼ 12 µm. We enhanced the co-culture properties through intracellular stimulation produced by piezoelectric nanostructures (i.e., boron nitride nanotubes activated by ultrasounds, thus exploiting the ability of boron nitride nanotubes to convert outer mechanical waves (such as ultrasounds in intracellular electrical stimuli, by exploiting the direct piezoelectric effect. We demonstrated that nanotubes were internalized by muscle cells and localized in both early and late endosomes, while they were not internalized by the underneath fibroblast layer. Muscle cell differentiation benefited from the synergic combination of topographical, mechanical, chemical and nanoparticle-based stimuli, showing good myotube development and alignment towards a preferential direction, as well as high expression of genes encoding key proteins for muscle contraction (i.e., actin and myosin. We also clarified the possible role of fibroblasts in this process, highlighting their response to the above mentioned physical stimuli in terms of gene expression and cytokine production. Finally, calcium imaging-based experiments demonstrated a higher functionality of the stimulated co-cultures.

  19. 3D-printed microfluidic chips with patterned, cell-laden hydrogel constructs.

    Science.gov (United States)

    Knowlton, Stephanie; Yu, Chu Hsiang; Ersoy, Fulya; Emadi, Sharareh; Khademhosseini, Ali; Tasoglu, Savas

    2016-01-01

    Three-dimensional (3D) printing offers potential to fabricate high-throughput and low-cost fabrication of microfluidic devices as a promising alternative to traditional techniques which enables efficient design iterations in the development stage. In this study, we demonstrate a single-step fabrication of a 3D transparent microfluidic chip using two alternative techniques: a stereolithography-based desktop 3D printer and a two-step fabrication using an industrial 3D printer based on polyjet technology. This method, compared to conventional fabrication using relatively expensive materials and labor-intensive processes, presents a low-cost, rapid prototyping technique to print functional 3D microfluidic chips. We enhance the capabilities of 3D-printed microfluidic devices by coupling 3D cell encapsulation and spatial patterning within photocrosslinkable gelatin methacryloyl (GelMA). The platform presented here serves as a 3D culture environment for long-term cell culture and growth. Furthermore, we have demonstrated the ability to print complex 3D microfluidic channels to create predictable and controllable fluid flow regimes. Here, we demonstrate the novel use of 3D-printed microfluidic chips as controllable 3D cell culture environments, advancing the applicability of 3D printing to engineering physiological systems for future applications in bioengineering. PMID:27321481

  20. Mucin-Inspired Thermoresponsive Synthetic Hydrogels Induce Stasis in Human Pluripotent Stem Cells and Human Embryos

    Science.gov (United States)

    2016-01-01

    Human pluripotent stem cells (hPSCs; both embryonic and induced pluripotent) rapidly proliferate in adherent culture to maintain their undifferentiated state. However, for mammals exhibiting delayed gestation (diapause), mucin-coated embryos can remain dormant for days or months in utero, with their constituent PSCs remaining pluripotent under these conditions. Here we report cellular stasis for both hPSC colonies and preimplantation embryos immersed in a wholly synthetic thermoresponsive gel comprising poly(glycerol monomethacrylate)-poly(2-hydroxypropyl methacrylate) [PGMA55-PHPMA135] diblock copolymer worms. This hydroxyl-rich mucin-mimicking nonadherent 3D gel maintained PSC viability and pluripotency in the quiescent G0 state without passaging for at least 14 days. Similarly, gel-coated human embryos remain in a state of suspended animation (diapause) for up to 8 days. The discovery of a cryptic cell arrest mechanism for both hPSCs and embryos suggests an important connection between the cellular mechanisms that evoke embryonic diapause and pluripotency. Moreover, such synthetic worm gels offer considerable utility for the short-term (weeks) storage of either pluripotent stem cells or human embryos without cryopreservation.

  1. Mucin-Inspired Thermoresponsive Synthetic Hydrogels Induce Stasis in Human Pluripotent Stem Cells and Human Embryos.

    Science.gov (United States)

    Canton, Irene; Warren, Nicholas J; Chahal, Aman; Amps, Katherine; Wood, Andrew; Weightman, Richard; Wang, Eugenia; Moore, Harry; Armes, Steven P

    2016-02-24

    Human pluripotent stem cells (hPSCs; both embryonic and induced pluripotent) rapidly proliferate in adherent culture to maintain their undifferentiated state. However, for mammals exhibiting delayed gestation (diapause), mucin-coated embryos can remain dormant for days or months in utero, with their constituent PSCs remaining pluripotent under these conditions. Here we report cellular stasis for both hPSC colonies and preimplantation embryos immersed in a wholly synthetic thermoresponsive gel comprising poly(glycerol monomethacrylate)-poly(2-hydroxypropyl methacrylate) [PGMA55-PHPMA135] diblock copolymer worms. This hydroxyl-rich mucin-mimicking nonadherent 3D gel maintained PSC viability and pluripotency in the quiescent G0 state without passaging for at least 14 days. Similarly, gel-coated human embryos remain in a state of suspended animation (diapause) for up to 8 days. The discovery of a cryptic cell arrest mechanism for both hPSCs and embryos suggests an important connection between the cellular mechanisms that evoke embryonic diapause and pluripotency. Moreover, such synthetic worm gels offer considerable utility for the short-term (weeks) storage of either pluripotent stem cells or human embryos without cryopreservation. PMID:27163030

  2. Rotary culture promotes the proliferation of MCF-7 cells encapsulated in three-dimensional collagen–alginate hydrogels via activation of the ERK1/2-MAPK pathway

    International Nuclear Information System (INIS)

    Rotary cell culture systems (RCCS) have been shown to be promising for promoting three-dimensional (3D) cell growth and assembly of cells into functional tissues. In this study, 3D tissue-like spheroids of MCF-7 cells were constructed by encapsulating the cells in the collagen–alginate hydrogel, and then cultured in a RCCS to investigate the proliferation of MCF-7 cells. The results from the MTT assay showed that the proliferation rate of MCF-7 cells cultured in the RCCS was higher than that of the static culture control group, and the results from the flow cytometry revealed that the cells in S and G2/M phase were significantly increased compared to the control group. The expression of cell proliferation antigen PCNA and cyclin D1 was also examined with the results further supporting the enhanced proliferation of MCF-7 cells by the RCCS. The results from indirect immunofluorescence revealed that the rotary culture altered neither the cytoskeleton distribution nor the assembly of mitotic spindle. By examination, it was also shown that the rotary culture induced the ERK1/2-MAPK pathway. Taken together, this study demonstrated that the rotary culture could promote the proliferation of MCF-7 cells by inducing the ERK1/2 pathway. (paper)

  3. Differentiation of human gingival mesenchymal stem cells into neuronal lineages in 3D bioconjugated injectable protein hydrogel construct for the management of neuronal disorder.

    Science.gov (United States)

    Rao, Suresh Ranga; Subbarayan, Rajasekaran; Dinesh, Murugan Girija; Arumugam, Gnanamani; Raja, Selvaraj Thirupathi Kumara

    2016-01-01

    The success of regeneration attempt is based on an ideal combination of stem cells, scaffolding and growth factors. Tissue constructs help to maintain stem cells in a required area for a desired time. There is a need for easily obtainable cells, potentially autologous stem cells and a biologically acceptable scaffold for use in humans in different difficult situations. This study aims to address these issues utilizing a unique combination of stem cells from gingiva and a hydrogel scaffold, based on a natural product for regenerative application. Human gingival mesenchymal stem cells (HGMSCs) were, with due induction, differentiated to neuronal lineages to overcome the problems associated with birth tissue-related stem cells. The differentiation potential of neuronal lineages was confirmed with suitable specific markers. The properties of mesenchymal stem cells in encapsulated form were observed to be similar to free cells. The encapsulated cells (3D) were then subjected to differentiation into neuronal lineages with suitable inducers, and the morphology and gene expression of transient cells were analyzed. HGMSCs was differentiated into neuronal lineages as both free and encapsulated forms without any significant differences. The presence of Nissl bodies and the neurite outgrowth confirm the differentiation. The advantages of this new combination appear to make it a promising tissue construct for translational application. PMID:26869025

  4. Differentiation of human gingival mesenchymal stem cells into neuronal lineages in 3D bioconjugated injectable protein hydrogel construct for the management of neuronal disorder

    Science.gov (United States)

    Rao, Suresh Ranga; Subbarayan, Rajasekaran; Dinesh, Murugan Girija; Arumugam, Gnanamani; Raja, Selvaraj Thirupathi Kumara

    2016-01-01

    The success of regeneration attempt is based on an ideal combination of stem cells, scaffolding and growth factors. Tissue constructs help to maintain stem cells in a required area for a desired time. There is a need for easily obtainable cells, potentially autologous stem cells and a biologically acceptable scaffold for use in humans in different difficult situations. This study aims to address these issues utilizing a unique combination of stem cells from gingiva and a hydrogel scaffold, based on a natural product for regenerative application. Human gingival mesenchymal stem cells (HGMSCs) were, with due induction, differentiated to neuronal lineages to overcome the problems associated with birth tissue-related stem cells. The differentiation potential of neuronal lineages was confirmed with suitable specific markers. The properties of mesenchymal stem cells in encapsulated form were observed to be similar to free cells. The encapsulated cells (3D) were then subjected to differentiation into neuronal lineages with suitable inducers, and the morphology and gene expression of transient cells were analyzed. HGMSCs was differentiated into neuronal lineages as both free and encapsulated forms without any significant differences. The presence of Nissl bodies and the neurite outgrowth confirm the differentiation. The advantages of this new combination appear to make it a promising tissue construct for translational application. PMID:26869025

  5. A new seed-train expansion method for recombinant mammalian cell lines.

    Science.gov (United States)

    Heidemann, Rüdiger; Mered, Mokhtar; Wang, D Q; Gardner, Bruce; Zhang, Chun; Michaels, James; Henzler, Hans-Jürgen; Abbas, Nada; Konstantinov, Konstantin

    2002-01-01

    A new approach has been developed and used to minimize the timeand more carefully monitor and control the seed-train expansionprocess of recombinant mammalian cell lines. The process uses 50or 100 ml cryo-bags that contain frozen cells at high cell densities of 20 x 10(6) ml(-1) (100 ml bags) or 40 x 10(6) cells ml(-1) (50 ml bags). The frozen bag cell suspension is thawed and transferred directly into a bioreactorthat has been modified such that pH, DO and temperature can becontrolled at the initial volume of two liters (the working volume eventually increases to 12 l). The successful use of thesecryo-bags and the modified ;inoculation' bioreactor to initiate anew seed train expansion of rBHK or rCHO cells is described herein. The interval between cell thawing and the accumulation ofsufficient cell mass to inoculate a production reactor is reducedby at least 25 to 30 days compared to the conventional method that begins with the thaw of 1-2 ml cryo-vials. This ;one-step'technology leads to a much more consistent scale-up by reducingmanual operations and avoiding subjective decisions during the scale-up phase. The cell metabolic rates and product integritywere similar to the control experiments. Furthermore, it was found that it is not necessary to include a wash step to removeDMSO prior to the inoculation. PMID:19003091

  6. Combined effects of C225 and 125-iodine seed radiation on colorectal cancer cells

    International Nuclear Information System (INIS)

    To characterize the effect of combined treatment of the anti-epidermal growth factor receptor (EGFR) monoclonal antibody C225 and 125-iodine (125I) seed radiation in human colorectal cancer. We treated LS180 cells with 125I continuous low dose rate radiation in the presence and absence of 100 nM C225. The clonogenic capacity, cellular proliferation, cell cycle distribution, apoptosis, and molecular pathways of the cells following the treatments were analyzed in vitro. The sensitizer enhancement ratio of C225 was approximately 1.4. Treatment with C225 and radiation alone produced significant inhibition of cell growth, but combination therapy produced greater inhibition than either treatment administered alone. C225 increased the radiation-induced apoptosis and the fraction of γ-H2AX foci positive cells at 48 h after treatment. The Akt phosphorylation level was lower in the cells receiving the combination treatment than in the cells treated with radiation or C225 alone. These findings indicate that C225 sensitizes LS180 cells to 125I seed radiation. Growth inhibition is mediated by inducing apoptosis and not cell cycle arrest. Additionally, we confirmed that C225 impairs DNA repair by reducing the cellular level of the DNA-PKcs and Ku70 proteins. Furthermore, the inhibition of Akt signaling activation may be responsible for the C225-mediated radiosensitization

  7. Printing thermoresponsive reverse molds for the creation of patterned two-component hydrogels for 3D cell culture.

    Science.gov (United States)

    Müller, Michael; Becher, Jana; Schnabelrauch, Matthias; Zenobi-Wong, Marcy

    2013-01-01

    Bioprinting is an emerging technology that has its origins in the rapid prototyping industry. The different printing processes can be divided into contact bioprinting(1-4) (extrusion, dip pen and soft lithography), contactless bioprinting(5-7) (laser forward transfer, ink-jet deposition) and laser based techniques such as two photon photopolymerization(8). It can be used for many applications such as tissue engineering(9-13), biosensor microfabrication(14-16) and as a tool to answer basic biological questions such as influences of co-culturing of different cell types(17). Unlike common photolithographic or soft-lithographic methods, extrusion bioprinting has the advantage that it does not require a separate mask or stamp. Using CAD software, the design of the structure can quickly be changed and adjusted according to the requirements of the operator. This makes bioprinting more flexible than lithography-based approaches. Here we demonstrate the printing of a sacrificial mold to create a multi-material 3D structure using an array of pillars within a hydrogel as an example. These pillars could represent hollow structures for a vascular network or the tubes within a nerve guide conduit. The material chosen for the sacrificial mold was poloxamer 407, a thermoresponsive polymer with excellent printing properties which is liquid at 4 °C and a solid above its gelation temperature ~20 °C for 24.5% w/v solutions(18). This property allows the poloxamer-based sacrificial mold to be eluted on demand and has advantages over the slow dissolution of a solid material especially for narrow geometries. Poloxamer was printed on microscope glass slides to create the sacrificial mold. Agarose was pipetted into the mold and cooled until gelation. After elution of the poloxamer in ice cold water, the voids in the agarose mold were filled with alginate methacrylate spiked with FITC labeled fibrinogen. The filled voids were then cross-linked with UV and the construct was imaged with an

  8. Layer by Layer Three-dimensional Tissue Epitaxy by Cell-Laden Hydrogel Droplets

    OpenAIRE

    Moon, SangJun; Hasan, Syed K.; Song, Young S.; Xu, Feng; Keles, Hasan Onur; Manzur, Fahim; Mikkilineni, Sohan; Hong, Jong Wook; Nagatomi, Jiro; Haeggstrom, Edward; Khademhosseini, Ali; Demirci, Utkan

    2009-01-01

    The ability to bioengineer three-dimensional (3D) tissues is a potentially powerful approach to treat diverse diseases such as cancer, loss of tissue function, or organ failure. Traditional tissue engineering methods, however, face challenges in fabricating 3D tissue constructs that resemble the native tissue microvasculature and microarchitectures. We have developed a bioprinter that can be used to print 3D patches of smooth muscle cells (5 mm × 5 mm × 81 μm) encapsulated within collagen. Cu...

  9. Cytotoxicity activities of chloroform extract of Cichorium intybus seed against HCT-15 and Vero cell line

    Directory of Open Access Journals (Sweden)

    Prashant Y Mali

    2015-01-01

    Full Text Available Background: Cichorium intybus L., (Asteraceae is well-known as a coffee substitute but is also widely used medicinally to treat various ailments ranging from wounds to diabetes. Other plant parts are also used for liver and cancer disorder. Objective: The objective was to study the cytotoxic potential of chloroform extract of C. intybus seed against HCT-15 and Vero (normal cell line. Materials and Methods: Fourier transform infrared spectroscopy (FTIR analysis of the extract was performed. 3-(4, 5-dimethylthiazol-2-yl-2, 5-diphenyl tetrazolium bromide assay was used for evaluation of the cytotoxic potential of chloroform extract of C. intybus seed. Doxorubicin was considered as standard reference drug. The concentrations 1000–0.05 μg/ml was used in the experiment. Result and Discussion: FTIR spectrum showed 1025.363, 1083.126, 1291.366, 1389.144, and 1569.294 peaks/centers in the wavelength region of 4,000.00–650.00 cm−1. The chloroform extract of C. intybus seed and doxorubicin was showed 1411.37 μg/ml and 460.13 μg/ml 50% cell growth inhibition (IC50 against the HCT-15 cell line. Both extract and doxorubicin were safe against the Vero (normal cell line. Conclusion: It can be concluded that the chloroform extract of C. intybus seed was not efficient against the HCT-15 cell line at the concentrations used in the experiment. Furthermore, there is no need to explore the said studies by in vivo models.

  10. Tunable Biodegradable Nanocomposite Hydrogel for Improved Cisplatin Efficacy on HCT-116 Colorectal Cancer Cells and Decreased Toxicity in Rats.

    Science.gov (United States)

    Abdel-Bar, Hend Mohamed; Osman, Rihab; Abdel-Reheem, Amal Youssef; Mortada, Nahed; Awad, Gehanne A S

    2016-02-01

    This work describes the development of a modified nanocomposite thermosensitive hydrogel for controlled cisplatin release and improved cytotoxicity with decreased side effects. The system was characterized in terms of physical properties, morphological architecture and in vitro cisplatin release. Cytotoxicity was tested against human colorectal carcinoma HCT-116. In vivo studies were conducted to evaluate the acute toxicity in terms of rats' survival rate and body weight loss. Nephro and hepatotoxicities were evaluated followed by histopathological alterations of various tissue organs. Nanocomposite thermosensitive hydrogel containing nanosized carrier conferred density and stiffness allowing a zero order drug release for 14 days. Enhanced cytotoxicity with 2-fold decrease in cisplatin IC50 was accomplished. A linear in vivo-in vitro correlation was proved for the system degradation. Higher animal survival rate and lower tissue toxicities proved the decreased toxicity of cisplatin nanocomposite compared to its solution. PMID:26709447

  11. Biomimetic hydrogel materials

    Science.gov (United States)

    Bertozzi, Carolyn; Mukkamala, Ravindranath; Chen, Qing; Hu, Hopin; Baude, Dominique

    2000-01-01

    Novel biomimetic hydrogel materials and methods for their preparation. Hydrogels containing acrylamide-functionalized carbohydrate, sulfoxide, sulfide or sulfone copolymerized with a hydrophilic or hydrophobic copolymerizing material selected from the group consisting of an acrylamide, methacrylamide, acrylate, methacrylate, vinyl and a derivative thereof present in concentration from about 1 to about 99 wt %. and methods for their preparation. The method of use of the new hydrogels for fabrication of soft contact lenses and biomedical implants.

  12. Aligned 3D human aortic smooth muscle tissue via layer by layer technique inside microchannels with novel combination of collagen and oxidized alginate hydrogel.

    Science.gov (United States)

    Rayatpisheh, Shahrzad; Poon, Yin Fun; Cao, Ye; Feng, Jie; Chan, Vincent; Chan-Park, Mary B

    2011-08-01

    Tissue engineering of the small diameter blood vessel medial layer has been challenging. Recreation of the circumferentially aligned multilayer smooth muscle tissue has been one of the major technical difficulties. Some research has utilized cyclic stress to align smooth muscle cells (SMCs) but due to the long time conditioning needed, it was not possible to use primary human cells because of expeditious senescence occurred . We demonstrate rapid buildup of a homogeneous relatively thick (30-40 μm) aligned smooth muscle tissue via layer by layer (LBL) technique within microchannels and a soft cell-adhesive hydrogel. Using a microchannelled scaffold with gapped microwalls, two layers of primary human SMCs separated by an interlayer hydrogel were cultured to confluence within the microchannels. The SMCs aligned along the microchannels because of the physically constraining microwalls. A novel double layered gel consisting of a mixture of pristine and oxidized alginate hydrogel coated with collagen was designed to place between each layer of cells, leading to a thicker tissue in a shorter time. The SMCs penetrated the soft thin interlayer hydrogel within 6 days of seeding of the 2nd cell layer so that the entire construct became more or less homogeneously populated by the SMCs. The unique LBL technique applied within the micropatterned scaffold using a soft cell-adhesive gel interlayer allows rapid growth and confluence of SMCs on 2D surface but at the same time aligns the cells and builds up multiple layers into a 3D tissue. This pseudo-3D buildup method avoids the typical steric resistance of hydrogel embedding. PMID:21548018

  13. Incorporation of bioactive ligand to methacrylate hydrogel surface through avidin-biotin complex for targeted cell cultivation

    Czech Academy of Sciences Publication Activity Database

    Hobzová, Radka; Kostina, Nina Yu.; Mareková, Dana; Širc, Jakub; Michálek, Jiří

    Kathmandu : Nepal Polymer Institute, 2011. s. 194. ISBN 9937-2-3292-9. [POLYCHAR 19 - World Forum on Advanced Materials. 20.03.2011-24.03.2011, Kathmandu] R&D Projects: GA ČR GA304/07/1129; GA MŠk 1M0538 Institutional research plan: CEZ:AV0Z40500505; CEZ:AV0Z50390703 Keywords : hydrogels * surface * modification Subject RIV: FJ - Surgery incl. Transplants

  14. Microfluidic monitoring of programmed cell death in living plant seed tissue

    DEFF Research Database (Denmark)

    Mark, Christina; Heiskanen, Arto; Zor, Kinga;

    Programmed cell death (PCD) is a highly regulated process in which cells are dismantled. Reactive oxygen species (ROS) are involved in PCD in plants, but the relationship between and mechanisms behind ROS and PCD are only poorly understood in plant cells compared to in animal cells (Gechev, Tsanko......, et al., (2006), BioEssays, 28, p. 1091). Microfluidic cell culture enables in vitro experiments to approach in vivo conditions. Combining microfluidics with the Lab-On-a-Chip concept allows implementing a wide range of assays for real-time monitoring of effects in a biological system of factors such...... as concentration of selected compounds, external pH, oxygen consumption, redox state and cell viability. The aleurone layer of the barley seed is a 2-3 single cell type thick tissue that can be dissected from the embryo and starchy endosperm. During incubation in vitro this mechanically very robust...

  15. Tumor Cell Seeding During Surgery—Possible Contribution to Metastasis Formations

    Energy Technology Data Exchange (ETDEWEB)

    Katharina, Pachmann [Department of Experimental Hematology and Oncology, Clinic for Internal Medicine II, Friedrich Schiller University, Jena D-07747 (Germany)

    2011-06-08

    In spite of optimal local control in breast cancer, distant metastases can develop as a systemic part of this disease. Surgery is suspected to contribute to metastasis formation activating dormant tumor cells. Here we add data that seeding of cells during surgery may add to the risk of metastasis formation. The change in circulating epithelial tumor cells (CETC) was monitored in 66 breast cancer patients operated on with breast conserving surgery or mastectomy and during the further course of the disease, analyzing CETC from unseparated white blood cells stained with FITC-anti-EpCAM. An increase in cell numbers lasting until the start of chemotherapy was observed in about one third of patients. It was more preeminent in patients with low numbers of CETC before surgery and, surprisingly, in patients without involved lymph nodes. Patients with the previously reported behavior—Reincrease in cell numbers during adjuvant chemotherapy and subsequent further increase during maintenance therapy—were at increased risk of relapse. In addition to tumor cells already released during growth of the tumor, cell seeding during surgery may contribute to the early peak of relapses observed after removal of the primary tumor and chemotherapy may only marginally postpone relapse in patients with aggressively growing tumors.

  16. Tumor Cell Seeding During Surgery—Possible Contribution to Metastasis Formations

    International Nuclear Information System (INIS)

    In spite of optimal local control in breast cancer, distant metastases can develop as a systemic part of this disease. Surgery is suspected to contribute to metastasis formation activating dormant tumor cells. Here we add data that seeding of cells during surgery may add to the risk of metastasis formation. The change in circulating epithelial tumor cells (CETC) was monitored in 66 breast cancer patients operated on with breast conserving surgery or mastectomy and during the further course of the disease, analyzing CETC from unseparated white blood cells stained with FITC-anti-EpCAM. An increase in cell numbers lasting until the start of chemotherapy was observed in about one third of patients. It was more preeminent in patients with low numbers of CETC before surgery and, surprisingly, in patients without involved lymph nodes. Patients with the previously reported behavior—Reincrease in cell numbers during adjuvant chemotherapy and subsequent further increase during maintenance therapy—were at increased risk of relapse. In addition to tumor cells already released during growth of the tumor, cell seeding during surgery may contribute to the early peak of relapses observed after removal of the primary tumor and chemotherapy may only marginally postpone relapse in patients with aggressively growing tumors

  17. Antiproliferative and Apoptotic Effects Triggered by Grape Seed Extract (GSE versus Epigallocatechin and Procyanidins on Colon Cancer Cell Lines

    Directory of Open Access Journals (Sweden)

    Simona Dinicola

    2012-01-01

    Full Text Available Grape seed extract has been proven to exert anticancer effects on different tumors. These effects are mainly ascribed to catechin and procyanidin content. Analytical studies demonstrated that grape seed extract composition is complex and it is likely other components could exert biological activities. Using cell count and flow cytometry assays, we evaluated the cytostatic and apoptotic effects produced by three different grape seed extracts from Italia, Palieri and Red Globe cultivars, on Caco2 and HCT-8 colon cancer cells. These effects were compared to those induced by epigallocatechin and procyanidins, alone or in association, on the same cell lines. All the extracts induced growth inhibition and apoptosis in Caco2 and HCT-8 cells, along the intrinsic apoptotic pathway. On both cell lines, growth inhibition induced by Italia and Palieri grape seed extracts was significantly higher than that it has been recorded with epigallocatechin, procyanidins and their association. In Caco2 cells, the extract from Red Globe cultivar was less effective in inducing growth inhibition than procyanidins alone and in association with epigallocatechin, whereas, in HCT-8 cells, only the association of epigallocatechin and procyanidins triggers a significant proliferation decrease. On both cell lines, apoptosis induced by Italia, Palieri and Red Globe grape seed extracts was considerably higher than has been recorded with epigallocatechin, procyanidins and their association. These data support the hypothesis by which other compounds, present in the grape seed extracts, are likely to enhance the anticancer effects.

  18. PVA/atapulgite hydrogels

    International Nuclear Information System (INIS)

    PVA hydrogels can be used as wound-healing as a consequence of their biocompatibility, flexibility, etc. In order to improve mechanical resistance of wound-healing, polymeric hydrogels reinforced with clay have been studied. Among national clays, attapulgite stands out. Once it is a natural material, acid treatment can be required in order to remove impurities. In the present work, PVA hydrogels reinforced with attapulgite were produced and they were characterized by swelling behavior, XRD, DSC and traction test. Among all properties studied, hydrogels reinforced with activated attapulgite showed better mechanical resistance and Young module than the other samples. (author)

  19. Dyes extracted from Trigonella seeds as photosensitizers for dye-sensitized solar cells

    Science.gov (United States)

    Batniji, Amal; Abdel-Latif, Monzir S.; El-Agez, Taher M.; Taya, Sofyan A.; Ghamri, Hatem

    2016-06-01

    In this paper, the extract of Trigonella seeds was used as sensitizer for dye-sensitized solar cells (DSSCs). The natural dye was extracted from the seeds using water and alcohol as solvents for the raw material. The UV-Vis absorption spectra of Trigonella extract solution and dye adsorbed on TiO2 film were measured. DSSCs sensitized by Trigonella extracted using water as a solvent exhibited better performance with efficiency of 0.215 %. The performance of the fabricated DSSCs was attempted to enhance by acid treatment of the FTO substrates with HNO3, H3PO4, and H2SO4. Electrochemical impedance spectroscopy of the fabricated cells was also carried out.

  20. Study On The Application Of Nutrient Immobilized Hydrogel As A Substrate For Hydroponics Culture

    International Nuclear Information System (INIS)

    The aim of this study is preparation of a nutrient hydrogel from CMC by irradiation for hydroponics culture. The hydrogel with different swelling prepared from CMC combined with PAM, nutrient and alginate by gamma-Co-60 irradiation. The hydrogel prepared by irradiation of the component with 20% CMC, 20% PAM, 1% alginate and nutrients at 15 kGy was suitable for the growth and development of plants. In particularly, the hydrogel showed a positive effect on germination ratio of seeds, the growth of 14 days seedling and the growth of lettuce and Chinese mustard in hydroponics cultivation. The hydrogel was completely collapsed after 5 weeks use in a hydroponics culture. The hydrogel showed a promising for application in hydroponics culture, a new technique for production of high yield and high quality vegetables. (NHA)

  1. Effect of 211At treating pollen and stigma on generative cells and seed setting of rice

    Institute of Scientific and Technical Information of China (English)

    JinJian-Nan; ChenFang; 等

    1998-01-01

    Low specific radioactivity (7.4kBq/ml) 211At treating pollen and stigma can obviously affect morphological structures and physiological functions of pollen,stigma and ovule or embryo sac cells,and cause injury.Results showed that because of the radiation effects the seed setting rate of rice was decreased,and the development of some embryos were affected and others became abnormal.

  2. Cytotoxicity activities of chloroform extract of Cichorium intybus seed against HCT-15 and Vero cell line

    OpenAIRE

    Prashant Y Mali

    2015-01-01

    Background: Cichorium intybus L., (Asteraceae) is well-known as a coffee substitute but is also widely used medicinally to treat various ailments ranging from wounds to diabetes. Other plant parts are also used for liver and cancer disorder. Objective: The objective was to study the cytotoxic potential of chloroform extract of C. intybus seed against HCT-15 and Vero (normal) cell line. Materials and Methods: Fourier transform infrared spectroscopy (FTIR) analysis of the extract was performed....

  3. PlGF-MMP9-engineered iPS cells supported on a PEG-fibrinogen hydrogel scaffold possess an enhanced capacity to repair damaged myocardium

    OpenAIRE

    C Bearzi; Gargioli, C; Baci, D.; Fortunato, O; K. Shapira-Schweitzer; Kossover, O.; M. Latronico; Seliktar, D.; Condorelli, G; Rizzi, R

    2014-01-01

    Cell-based regenerative therapies are significantly improved by engineering allografts to express factors that increase vascularization and engraftment, such as placental growth factor (PlGF) and matrix metalloproteinase 9 (MMP9). Moreover, the seeding of therapeutic cells onto a suitable scaffold is of utmost importance for tissue regeneration. On these premises, we sought to assess the reparative potential of induced pluripotent stem (iPS) cells bioengineered to secrete PlGF or MMP9 and del...

  4. Biodistribution and Toxicity Studies of PRINT Hydrogel Nanoparticles in Mosquito Larvae and Cells.

    Science.gov (United States)

    Phanse, Yashdeep; Dunphy, Brendan M; Perry, Jillian L; Airs, Paul M; Paquette, Cynthia C H; Carlson, Jonathan O; Xu, Jing; Luft, J Christopher; DeSimone, Joseph M; Beaty, Barry J; Bartholomay, Lyric C

    2015-05-01

    Mosquito-borne diseases continue to remain major threats to human and animal health and impediments to socioeconomic development. Increasing mosquito resistance to chemical insecticides is a great public health concern, and new strategies/technologies are necessary to develop the next-generation of vector control tools. We propose to develop a novel method for mosquito control that employs nanoparticles (NPs) as a platform for delivery of mosquitocidal dsRNA molecules to silence mosquito genes and cause vector lethality. Identifying optimal NP chemistry and morphology is imperative for efficient mosquitocide delivery. Toward this end, fluorescently labeled polyethylene glycol NPs of specific sizes, shapes (80 nm x 320 nm, 80 nm x 5000 nm, 200 nm x 200 nm, and 1000 nm x 1000 nm) and charges (negative and positive) were fabricated by Particle Replication in Non-Wetting Templates (PRINT) technology. Biodistribution, persistence, and toxicity of PRINT NPs were evaluated in vitro in mosquito cell culture and in vivo in Anopheles gambiae larvae following parenteral and oral challenge. Following parenteral challenge, the biodistribution of the positively and negatively charged NPs of each size and shape was similar; intense fluorescence was observed in thoracic and abdominal regions of the larval body. Positively charged NPs were more associated with the gastric caeca in the gastrointestinal tract. Negatively charged NPs persisted through metamorphosis and were observed in head, body and ovaries of adults. Following oral challenge, NPs were detected in the larval mid- and hindgut. Positively charged NPs were more efficiently internalized in vitro than negatively charged NPs. Positively charged NPs trafficked to the cytosol, but negatively charged NPs co-localized with lysosomes. Following in vitro and in vivo challenge, none of the NPs tested induced any cytotoxic effects. PMID:25996390

  5. Development of bioartificial myocardium by electrostimulation of 3D collagen scaffolds seeded with stem cells

    Directory of Open Access Journals (Sweden)

    Alain Carpentier

    2012-06-01

    Full Text Available Electrostimulation (ES can be defined as a safe physical method to induce stem cell differentiation. The aim of this study is to evaluate the effectiveness of ES on bone marrow mesenchymal stem cells (BMSCs seeded in collagen scaffolds in terms of proliferation and differentiation into cardiomyocytes. BMSCs were isolated from Wistar rats and seeded into 3D collagen type 1 templates measuring 25 x 25 x 6 mm. Bipolar in vitro ES was performed during 21 days. Electrical impedance and cell proliferation were measured. Expression of cardiac markers was assessed by immunocytochemistry. Viscoelasticity of collagen matrix was evaluated. Electrical impedance assessments showed a low resistance of 234±41 Ohms which indicates good electrical conductivity of collagen matrix. Cell proliferation at 570 nm as significantly increased in ES groups after seven day (ES 0.129±0.03 vs non-stimulated control matrix 0.06±0.01, P=0.002 and after 21 days, (ES 0.22±0.04 vs control 0.13±0.01, P=0.01. Immunocytochemistry of BMSCs after 21 days ES showed positive staining of cardiac markers, troponin I, connexin 43, sarcomeric alpha-actinin, slow myosin, fast myosin and desmin. Staining for BMSCs marker CD29 after 21 days was negative. Electrostimulation of cell-seeded collagen matrix changed stem cell morphology and bio- chemical characteristics, increasing the expression of cardiac markers. Thus, MSC-derived differentiated cells by electrostimulation grafted in biological scaffolds might result in a convenient tissue engineering source for myocardial diseases.

  6. Evaluation of fibroblasts adhesion and proliferation on alginate-gelatin crosslinked hydrogel.

    Directory of Open Access Journals (Sweden)

    Bapi Sarker

    Full Text Available Due to the relatively poor cell-material interaction of alginate hydrogel, alginate-gelatin crosslinked (ADA-GEL hydrogel was synthesized through covalent crosslinking of alginate di-aldehyde (ADA with gelatin that supported cell attachment, spreading and proliferation. This study highlights the evaluation of the physico-chemical properties of synthesized ADA-GEL hydrogels of different compositions compared to alginate in the form of films. Moreover, in vitro cell-material interaction on ADA-GEL hydrogels of different compositions compared to alginate was investigated by using normal human dermal fibroblasts. Viability, attachment, spreading and proliferation of fibroblasts were significantly increased on ADA-GEL hydrogels compared to alginate. Moreover, in vitro cytocompatibility of ADA-GEL hydrogels was found to be increased with increasing gelatin content. These findings indicate that ADA-GEL hydrogel is a promising material for the biomedical applications in tissue-engineering and regeneration.

  7. Bio-functionalized silk hydrogel microfluidic systems.

    Science.gov (United States)

    Zhao, Siwei; Chen, Ying; Partlow, Benjamin P; Golding, Anne S; Tseng, Peter; Coburn, Jeannine; Applegate, Matthew B; Moreau, Jodie E; Omenetto, Fiorenzo G; Kaplan, David L

    2016-07-01

    Bio-functionalized microfluidic systems were developed based on a silk protein hydrogel elastomeric materials. A facile multilayer fabrication method using gelatin sacrificial molding and layer-by-layer assembly was implemented to construct interconnected, three dimensional (3D) microchannel networks in silk hydrogels at 100 μm minimum feature resolution. Mechanically activated valves were implemented to demonstrate pneumatic control of microflow. The silk hydrogel microfluidics exhibit controllable mechanical properties, long-term stability in various environmental conditions, tunable in vitro and in vivo degradability in addition to optical transparency, providing unique features for cell/tissue-related applications than conventional polydimethylsiloxane (PDMS) and existing hydrogel-based microfluidic options. As demonstrated in the work here, the all aqueous-based fabrication process at ambient conditions enabled the incorporation of active biological substances in the bulk phase of these new silk microfluidic systems during device fabrication, including enzymes and living cells, which are able to interact with the fluid flow in the microchannels. These silk hydrogel-based microfluidic systems offer new opportunities in engineering active diagnostic devices, tissues and organs that could be integrated in vivo, and for on-chip cell sensing systems. PMID:27077566

  8. Engineered Polymeric Hydrogels for 3D Tissue Models

    Directory of Open Access Journals (Sweden)

    Sujin Park

    2016-01-01

    Full Text Available Polymeric biomaterials are widely used in a wide range of biomedical applications due to their unique properties, such as biocompatibility, multi-tunability and easy fabrication. Specifically, polymeric hydrogel materials are extensively utilized as therapeutic implants and therapeutic vehicles for tissue regeneration and drug delivery systems. Recently, hydrogels have been developed as artificial cellular microenvironments because of the structural and physiological similarity to native extracellular matrices. With recent advances in hydrogel materials, many researchers are creating three-dimensional tissue models using engineered hydrogels and various cell sources, which is a promising platform for tissue regeneration, drug discovery, alternatives to animal models and the study of basic cell biology. In this review, we discuss how polymeric hydrogels are used to create engineered tissue constructs. Specifically, we focus on emerging technologies to generate advanced tissue models that precisely recapitulate complex native tissues in vivo.

  9. Hydrogels Constructed from Engineered Proteins.

    Science.gov (United States)

    Li, Hongbin; Kong, Na; Laver, Bryce; Liu, Junqiu

    2016-02-24

    Due to their various potential biomedical applications, hydrogels based on engineered proteins have attracted considerable interest. Benefitting from significant progress in recombinant DNA technology and protein engineering/design techniques, the field of protein hydrogels has made amazing progress. The latest progress of hydrogels constructed from engineered recombinant proteins are presented, mainly focused on biorecognition-driven physical hydrogels as well as chemically crosslinked hydrogels. The various bio-recognition based physical crosslinking strategies are discussed, as well as chemical crosslinking chemistries used to engineer protein hydrogels, and protein hydrogels' various biomedical applications. The future perspectives of this fast evolving field of biomaterials are also discussed. PMID:26707834

  10. Experiments with hydrogel pearls

    OpenAIRE

    Pavlin, Jerneja

    2015-01-01

    Hydrogels are very attractive materials since they can absorb large quantities of water. They also have very interesting optical properties which can be easily shown. The experiments with hydrogel pearls related to the absorption of water, density, optical properties and influence of pH are presented in the contribution.

  11. Rapid 3D printing of anatomically accurate and mechanically heterogeneous aortic valve hydrogel scaffolds

    International Nuclear Information System (INIS)

    The aortic valve exhibits complex three-dimensional (3D) anatomy and heterogeneity essential for the long-term efficient biomechanical function. These are, however, challenging to mimic in de novo engineered living tissue valve strategies. We present a novel simultaneous 3D printing/photocrosslinking technique for rapidly engineering complex, heterogeneous aortic valve scaffolds. Native anatomic and axisymmetric aortic valve geometries (root wall and tri-leaflets) with 12–22 mm inner diameters (ID) were 3D printed with poly-ethylene glycol-diacrylate (PEG-DA) hydrogels (700 or 8000 MW) supplemented with alginate. 3D printing geometric accuracy was quantified and compared using Micro-CT. Porcine aortic valve interstitial cells (PAVIC) seeded scaffolds were cultured for up to 21 days. Results showed that blended PEG-DA scaffolds could achieve over tenfold range in elastic modulus (5.3±0.9 to 74.6±1.5 kPa). 3D printing times for valve conduits with mechanically contrasting hydrogels were optimized to 14 to 45 min, increasing linearly with conduit diameter. Larger printed valves had greater shape fidelity (93.3±2.6, 85.1±2.0 and 73.3±5.2% for 22, 17 and 12 mm ID porcine valves; 89.1±4.0, 84.1±5.6 and 66.6±5.2% for simplified valves). PAVIC seeded scaffolds maintained near 100% viability over 21 days. These results demonstrate that 3D hydrogel printing with controlled photocrosslinking can rapidly fabricate anatomical heterogeneous valve conduits that support cell engraftment. (paper)

  12. Antileukemic Potential of Momordica charantia Seed Extracts on Human Myeloid Leukemic HL60 Cells

    Directory of Open Access Journals (Sweden)

    Ramani Soundararajan

    2012-01-01

    Full Text Available Momordica charantia (bitter gourd has been used in the traditional system of medicine for the treatment of various diseases. Anticancer activity of M. charantia extracts has been demonstrated by numerous in vitro and in vivo studies. In the present study, we investigated the differentiation inducing potential of fractionated M. charantia seed extracts in human myeloid HL60 cells. We found that the HL60 cells treated with the fractionated seed extracts differentiated into granulocytic lineage as characterized by NBT staining, CD11b expression, and specific esterase activity. The differentiation inducing principle was found to be heat-stable, and organic in nature. The differentiation was accompanied by a downregulation of c-myc transcript, indicating the involvement of c-myc pathway, at least in part, in differentiation. Taken together these results indicate that fractionated extracts of M. charantia seeds possess differentiation inducing activity and therefore can be evaluated for their potential use in differentiation therapy for leukemia in combination with other inducers of differentiation.

  13. Deleterious effects on MDAMB-231 breast adenocarcinoma cell lineage submitted to Ho-166 radioactive seeds at very low activity

    International Nuclear Information System (INIS)

    Herein, the deleterious effect of ionizing radiation provided by Ho-166 radioactive seeds at low activity were addressed, based on experimental in vitro assays at the MDA MB231 cell lineage, a breast adenocarcinoma, compared to PBMC - peripheral blood cells. The methodology involves of the MDBMB-231 and PBMC expansion in culture in suitable environment in 30mm well plates and T-25 flasks. Seeds were synthesized with Ho-165 incorporated and characterized previously. Activation was processed at IPR1 reactor at the peripheral table, at 8h exposition. Three groups of seeds were tested: 0,34 mCi, 0,12 mCi activity, and control group. Such seeds were placed on culture and held to a period of 05 half-lives of the radionuclide. The biological responses at these exposure were documented by inverse microscopic photographic in time. Also, MTT essay were performed. A fast response in producing deleterious effects at cancer cell was observed even if for the low activity seeds. Also, a biological response dependent to a radial distance of the seed was observed. At conclusion, viability clonogenic control of MDAMB231 is identified at the exposition to Ho-166 ceramic seeds, even if at low activity of 0,1 to 0,3mCi. (author)

  14. Deleterious effects on MDAMB-231 breast adenocarcinoma cell lineage submitted to Ho-166 radioactive seeds at very low activity

    Energy Technology Data Exchange (ETDEWEB)

    Falcao, Patricia L.; Campos, Tarcisio P.R., E-mail: campos@nuclear.ufmg.br [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Dept. de Engenharia Nuclear; Sarmento, Eduardo V. [Centro de Desenvolvimento de Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil); Cuperschmid, Ethel M. [Universidade Federal de Minas Gerais (CEMEMOR/UFMG), Belo Horizonte, BR (Brazil). Fac. de Medicina. Centro de Memoria da Medicina

    2011-07-01

    Herein, the deleterious effect of ionizing radiation provided by Ho-166 radioactive seeds at low activity were addressed, based on experimental in vitro assays at the MDA MB231 cell lineage, a breast adenocarcinoma, compared to PBMC - peripheral blood cells. The methodology involves of the MDBMB-231 and PBMC expansion in culture in suitable environment in 30mm well plates and T-25 flasks. Seeds were synthesized with Ho-165 incorporated and characterized previously. Activation was processed at IPR1 reactor at the peripheral table, at 8h exposition. Three groups of seeds were tested: 0,34 mCi, 0,12 mCi activity, and control group. Such seeds were placed on culture and held to a period of 05 half-lives of the radionuclide. The biological responses at these exposure were documented by inverse microscopic photographic in time. Also, MTT essay were performed. A fast response in producing deleterious effects at cancer cell was observed even if for the low activity seeds. Also, a biological response dependent to a radial distance of the seed was observed. At conclusion, viability clonogenic control of MDAMB231 is identified at the exposition to Ho-166 ceramic seeds, even if at low activity of 0,1 to 0,3mCi. (author)

  15. Fiber-reinforced tough hydrogels

    OpenAIRE

    Illeperuma, Widusha Ruwangi Kaushalya; Sun, Jeong-Yun; Suo, Zhigang; Vlassak, Joost J.

    2014-01-01

    Using strong fibers to reinforce a hydrogel is highly desirable but difficult. Such a composite would combine the attributes of a solid that provides strength and a liquid that transports matter. Most hydrogels, however, are brittle, allowing the fibers to cut through the hydrogel when the composite is loaded. Here we circumvent this problem by using a recently developed tough hydrogel. We fabricate a composite using an alginate-polyacrylamide hydrogel reinforced with a random network of stai...

  16. Preparation and characterization of cellulose composite hydrogels from tea residue and carbohydrate additives.

    Science.gov (United States)

    Liu, Zhijun; Huang, Huihua

    2016-08-20

    Composite hydrogels were prepared from tea cellulose in ionic liquid of 1-allyl-3-methylimidazolium chloride and effect of κ-carrageenan, chitosan, guar gum and soluble starch on characteristics of the prepared hydrogels were investigated. The prepared hydrogels were characterized via Fourier transform infrared, thermogravimetry analysis, differential scanning calorimetry. Sodium salicylate was used as the model drug to compare the swelling, drug loading and releasing kinetics of the prepared hydrogels. Thiazolyl blue tetrazolium bromide assay and relative growth rates were adopted to evaluate cell cytotoxicity and biocompatibility of the prepared hydrogels. Chitosan and guar gum could improve thermostability and mechanical characteristics of the composite hydrogels, while κ-carrageenan or soluble starch could improve equilibrium swelling ratio, sodium salicylate loading and releasing. Guar gum and chitosan could increase permeation resistance and were beneficial for release control of the hydrogels. Addition of chitosan, κ-carrageenan, guar gum and soluble starch were proven cell compatibility and non-cytotoxicity. PMID:27178928

  17. Direct influence of culture dimensionality on human mesenchymal stem cell differentiation at various matrix stiffnesses using a fibrous self-assembling peptide hydrogel.

    Science.gov (United States)

    Hogrebe, Nathaniel J; Gooch, Keith J

    2016-09-01

    Much is unknown about the effects of culture dimensionality on cell behavior due to the lack of biomimetic substrates that are suitable for directly comparing cells grown on two-dimensional (2D) and encapsulated within three-dimensional (3D) matrices of the same stiffness and biochemistry. To overcome this limitation, we used a self-assembling peptide hydrogel system that has tunable stiffness and cell-binding site density as well as a fibrous microarchitecture resembling the structure of collagen. We investigated the effect of culture dimensionality on human mesenchymal stem cell differentiation at different values of matrix stiffness (G' = 0.25, 1.25, 5, and 10 kPa) and a constant RGD (Arg-Gly-Asp) binding site concentration. In the presence of the same soluble induction factors, culture on top of stiff gels facilitated the most efficient osteogenesis, while encapsulation within the same stiff gels resulted in a switch to predominantly terminal chondrogenesis. Adipogenesis dominated at soft conditions, and 3D culture induced better adipogenic differentiation than 2D culture at a given stiffness. Interestingly, initial matrix-induced cell morphology was predictive of these end phenotypes. Furthermore, optimal culture conditions corresponded to each cell type's natural niche within the body, highlighting the importance of incorporating native matrix dimensionality and stiffness into tissue engineering strategies. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 104A: 2356-2368, 2016. PMID:27163888

  18. Exploring the Anticancer Activity of Grape Seed Extract on Skin Cancer Cell Lines A431

    Directory of Open Access Journals (Sweden)

    V. Mohansrinivasan

    2015-08-01

    Full Text Available In this study, grape seeds were extracted using ethyl acetate and petroleum ether by solvent-solvent extraction method. The phytochemical tests were performed to identify different phytochemical compounds present in the grape seed extract (GSE. Antibacterial activity of the GSE was determined using agar diffusion method against Gram- positive and Gram-negative bacteria. Gas chromatography-mass spectrometry (GC-MS and Fourier transform infrared spectroscopy (FTIR analysis was done to identify the presence of bioactive compounds and their functional groups. The GC-MS results revealed a total of four compounds, known to have potent activity against cancer cells, viz, squalene, the most potent compound found in ethyl acetate extract and diethyl phthalate, ethyl-9- cis -11- trans octadecadienoate and (R-(--14,-methyl-8-Hexadecyn-1-ol in petroleum ether extract. Cytotoxic activity of the GSE was observed against skin cancer cell lines A4321 using 3-(4, 5-dimethylthiazol-2-yl-2-5-diphenyl tetrazolium bromide MTT assay. The IC50 value of the GSE against A431 skin cancer cell line was 480 µg/mL. This is first such report against A4321 cell lines. The study gives the overall perception about importance of GSE in medicine and nutraceuticals purposes.

  19. Enhancement of cetuximab on radiosensitivity of colorectal cancer cells exposed to 125I seeds

    International Nuclear Information System (INIS)

    Objective: To investigate the effect of cetuximab (C225) on the radiosensitivity of colorectal cancer cells CL187 and underlying mechanism. Methods: Cell survival was detected by colony forming assay. The levels of apoptosis and cell cycle distribution were determined by flow cytometer. The mitotic ratio was measured by Wright's-Giemsa mixed coloring method. The protein levels of Bax and Bcl2 were detected by Western blot. Results: The sensitizing enhancement ratio of C225 was approximately 1.4. C225 treatment and 125I seed radiation induced G1 cell cycle arrest individually. C225 increased the radiation-induced apoptosis (t =6.6, P<0.05) and cellular Bax/Bcl-2 ratio (t =9.4, P<0.05), but did not increase radiation-induced G1 arrest. In addition, there was no difference in mitotic index among different groups. Conclusions: C225 sensitizes CL187 to 125I seed irradiation,which might be related with increase of radiation-induced apoptosis. (authors)

  20. Polyurethane scaffolds seeded with CD34(+) cells maintain early stem cells whilst also facilitating prolonged egress of haematopoietic progenitors.

    Science.gov (United States)

    Severn, Charlotte E; Macedo, Hugo; Eagle, Mark J; Rooney, Paul; Mantalaris, Athanasios; Toye, Ashley M

    2016-01-01

    We describe a 3D erythroid culture system that utilises a porous polyurethane (PU) scaffold to mimic the compartmentalisation found in the bone marrow. PU scaffolds seeded with peripheral blood CD34(+) cells exhibit a remarkable reproducibility of egress, with an increased output when directly compared to human bone scaffolds over 28 days. Immunofluorescence demonstrated the persistence of CD34(+) cells within the scaffolds for the entirety of the culture. To characterise scaffold outputs, we designed a flow cytometry panel that utilises surface marker expression observed in standard 2D erythroid and megakaryocyte cultures. This showed that the egress population is comprised of haematopoietic progenitor cells (CD36(+)GPA(-/low)). Control cultures conducted in parallel but in the absence of a scaffold were also generally maintained for the longevity of the culture albeit with a higher level of cell death. The harvested scaffold egress can also be expanded and differentiated to the reticulocyte stage. In summary, PU scaffolds can behave as a subtractive compartmentalised culture system retaining and allowing maintenance of the seeded "CD34(+) cell" population despite this population decreasing in amount as the culture progresses, whilst also facilitating egress of increasingly differentiated cells. PMID:27573994

  1. Mandibular Jaw Bone Regeneration Using Human Dental Cell-Seeded Tyrosine-Derived Polycarbonate Scaffolds.

    Science.gov (United States)

    Zhang, Weibo; Zhang, Zheng; Chen, Shuang; Macri, Lauren; Kohn, Joachim; Yelick, Pamela C

    2016-07-01

    Here we present a new model for alveolar jaw bone regeneration, which uses human dental pulp cells (hDPCs) combined with tyrosine-derived polycarbonate polymer scaffolds [E1001(1k)] containing beta-tricalcium phosphate (β-TCP) [E1001(1k)/β-TCP]. E1001(1k)/β-TCP scaffolds (5 mm diameter × 1 mm thickness) were fabricated to fit a 5 mm rat mandibular ramus critical bone defect. Five experimental groups were examined in this study: (1) E1001(1k)/β-TCP scaffolds seeded with a high density of hDPCs, 5.0 × 10(5) hDPCs/scaffold (CH); (2) E1001(1k)/β-TCP scaffolds seeded with a lower density of hDPCs, 2.5 × 10(5) hDPCs/scaffold (CL); (3) acellular E1001(1k)/β-TCP scaffolds (SA); (4) acellular E1001(1k)/β-TCP scaffolds supplemented with 4 μg recombinant human bone morphogenetic protein-2 (BMP); and (5) empty defects (EDs). Replicate hDPC-seeded and acellular E1001(1k)/β-TCP scaffolds were cultured in vitro in osteogenic media for 1 week before implantation for 3 and 6 weeks. Live microcomputed tomography (μCT) imaging at 3 and 6 weeks postimplantation revealed robust bone regeneration in the BMP implant group. CH and CL groups exhibited similar uniformly distributed mineralized tissue coverage throughout the defects, but less than the BMP implants. In contrast, SA-treated defects exhibited sparse areas of mineralized tissue regeneration. The ED group exhibited slightly reduced defect size. Histological analyses revealed no indication of an immune response. In addition, robust expression of dentin and bone differentiation marker expression was observed in hDPC-seeded scaffolds, whereas, in contrast, BMP and SA implants exhibited only bone and not dentin differentiation marker expression. hDPCs were detected in 3-week but not in 6-week hDPC-seeded scaffold groups, indicating their survival for at least 3 weeks. Together, these results show that hDPC-seeded E1001(1k)/β-TCP scaffolds support the rapid regeneration of osteo

  2. [Grape seed proanthocyanidins inhibits the invasion and migration of A549 lung cancer cells].

    Science.gov (United States)

    Zhou, Yehan; Ye, Xiufeng; Shi, Yao; Wang, Ke; Wan, Dan

    2016-02-01

    Objective To explore the effect of grape seed proanthocyanidins (GSPs) on the invasion and migration of A549 lung cancer cells and the underlying mechanism. Methods Trypan blue dye exclusion assay was used to determine the cytotoxic effect of varying doses of GSPs on the BEAS-2B normal human pulmonary epithelial cells. After treated with 0, 10, 20, 40, 80 μg/mL GSP, the proliferation of A549 cells was detected by MTT assay; the invasion and migration of A549 cells were determined by Transwell(TM) assay and scratch wound assay, respectively. The levels of epithelial growth factor receptor (EGFR), E-cadherin, N-cadherin in A549 cells treated with GSPs were detected by Western blotting. Results (0-40) μg/mL GSPs had no significant toxic effect on BEAS-2B cells, while 80 μg/mL GSPs had significant cytotoxicity to BEAS-2B cells. The proliferation of A549 cells was significantly inhibited within limited dosage in a dose-dependent manner, and the abilities of invasion and migration of A549 cells were also inhibited. Western blotting showed that the expression of EGFR and N-cadherin decreased, while E-cadherin increased after GSPs treatment. Conclusion GSPs could inhibit the abilities of proliferation, invasion and migration of A549 cells, which might be related to the dow-regulation of EGFR and N-cadherin and the up-regulation of E-cadherin. PMID:26927375

  3. Inkjet-bioprinted acrylated peptides and PEG hydrogel with human mesenchymal stem cells promote robust bone and cartilage formation with minimal printhead clogging.

    Science.gov (United States)

    Gao, Guifang; Yonezawa, Tomo; Hubbell, Karen; Dai, Guohao; Cui, Xiaofeng

    2015-10-01

    Inkjet bioprinting is one of the most promising additive manufacturing approaches for tissue fabrication with the advantages of high speed, high resolution, and low cost. The limitation of this technology is the potential damage to the printed cells and frequent clogging of the printhead. Here we developed acrylated peptides and co-printed with acrylated poly(ethylene glycol) (PEG) hydrogel with simultaneous photopolymerization. At the same time, the bone marrow-derived human mesenchymal stem cells (hMSCs) were precisely printed during the scaffold fabrication process so the cells were delivered simultaneously with minimal UV exposure. The multiple steps of scaffold synthesis and cell encapsulation were successfully combined into one single step using bioprinting. The resulted peptide-conjugated PEG scaffold demonstrated excellent biocompatibility, with a cell viability of 87.9 ± 5.3%. Nozzle clogging was minimized due to the low viscosity of the PEG polymer. With osteogenic and chondrogenic differentiation, the bioprinted bone and cartilage tissue demonstrated excellent mineral and cartilage matrix deposition, as well as significantly increased mechanical properties. Strikingly, the bioprinted PEG-peptide scaffold dramatically inhibited hMSC hypertrophy during chondrogenic differentiation. Collectively, bioprinted PEG-peptide scaffold and hMSCs significantly enhanced osteogenic and chondrogenic differentiation for robust bone and cartilage formation with minimal printhead clogging. PMID:25641582

  4. Characterization of electroless nickel as a seed layer for silicon solar cell metallization

    Indian Academy of Sciences (India)

    Mehul C Raval; Chetan S Solanki

    2015-02-01

    Electroless nickel plating is a suitable method for seed layer deposition in Ni–Cu-based solar cell metallization. Nickel silicide formation and hence contact resistivity of the interface is largely influenced by the plating process and annealing conditions. In the present work, a thin seed layer is deposited from neutral pH and alkaline electroless nickel baths which are annealed in the range of 400–420°C for silicide morphology and contact resistivity studies. A minimum contact resistivity of 7 m cm2 is obtained for seed layer deposited from alkaline bath. Silicide formation for Pd-activated samples leads to uniform surface morphology as compared with unactivated samples due to non-homogeneous migration of nickel atoms at the interface. Formation of nickel phosphides during annealing and the presence of SiO2 at Ni–Si interface creates isolated Ni2Si–Si interface with limited supply of silicon. Such an interface leads to the formation of high resistivity metal-rich Ni3Si silicide phase which limits the reduction in contact resistivity.

  5. 5-FU-hydrogel inhibits colorectal peritoneal carcinomatosis and tumor growth in mice

    International Nuclear Information System (INIS)

    Colorectal peritoneal carcinomatosis (CRPC) is a common form of systemic metastasis of intra-abdominal cancers. Intraperitoneal chemotherapy is a preferable option for colorectal cancer. Here we reported that a new system, 5-FU-loaded hydrogel system, can improve the therapeutic effects of intraperitoneal chemotherapy. A biodegradable PEG-PCL-PEG (PECE) triblock copolymer was successfully synthesized. The biodegradable and temperature sensitive hydrogel was developed to load 5-FU. Methylene blue-loaded hydrogel were also developed for visible observation of the drug release. The effects and toxicity of the 5-FU-hydrogel system were evaluated in a murine CRPC model. The hydrogel system is an injectable flowing solution at ambient temperature and forms a non-flowing gel depot at physiological temperature. 5-FU-hydrogel was subsequently injected into abdominal cavity in mice with CT26 cancer cells peritoneal dissemination. The results showed that the hydrogel delivery system prolonged the release of methylene blue; the 5-FU-hydrogel significantly inhibited the peritoneal dissemination and growth of CT26 cells. Furthermore, intraperitoneal administration of the 5-FU-hydrogel was well tolerated and showed less hematologic toxicity. Our data indicate that the 5-FU-hydrogel system can be considered as a new strategy for peritoneal carcinomatosis, and the hydrogel may provide a potential delivery system to load different chemotherapeutic drugs for peritoneal carcinomatosis of cancers

  6. Inhibitory potential of rambutan seeds extract and fractions on adipogenesis in 3T3-L1 cell line

    OpenAIRE

    Sylvia Soeng; Endang Evacuasiany; Wahyu Widowati; Nurul Fauziah; Visi Tinta Manik; Maesaroh Maesaroh

    2015-01-01

    Objective: Type 2 diabetes is a global health problem with increasing prevalence related to several conditions; one of these is due to obesity. Rambutan (Nephelium lappaceum L) seeds contain various phenolic compounds. The present study was designed to evaluate the phytochemical content and the inhibitory potential of rambutan seeds extract and fractions on glucose-6-phosphate dehydrogenase (G6PDH), and #945;-glucosidase, and triglyceride activities ex vivo in 3T3-L1 cell line (pre-adipocyte...

  7. Polyurethane scaffolds seeded with CD34+ cells maintain early stem cells whilst also facilitating prolonged egress of haematopoietic progenitors

    Science.gov (United States)

    Severn, Charlotte E.; Macedo, Hugo; Eagle, Mark J.; Rooney, Paul; Mantalaris, Athanasios; Toye, Ashley M.

    2016-01-01

    We describe a 3D erythroid culture system that utilises a porous polyurethane (PU) scaffold to mimic the compartmentalisation found in the bone marrow. PU scaffolds seeded with peripheral blood CD34+ cells exhibit a remarkable reproducibility of egress, with an increased output when directly compared to human bone scaffolds over 28 days. Immunofluorescence demonstrated the persistence of CD34+ cells within the scaffolds for the entirety of the culture. To characterise scaffold outputs, we designed a flow cytometry panel that utilises surface marker expression observed in standard 2D erythroid and megakaryocyte cultures. This showed that the egress population is comprised of haematopoietic progenitor cells (CD36+GPA−/low). Control cultures conducted in parallel but in the absence of a scaffold were also generally maintained for the longevity of the culture albeit with a higher level of cell death. The harvested scaffold egress can also be expanded and differentiated to the reticulocyte stage. In summary, PU scaffolds can behave as a subtractive compartmentalised culture system retaining and allowing maintenance of the seeded “CD34+ cell” population despite this population decreasing in amount as the culture progresses, whilst also facilitating egress of increasingly differentiated cells. PMID:27573994

  8. Bioactive Gyroid Scaffolds Formed by Sacrificial Templating of Nanocellulose and Nanochitin Hydrogels as Instructive Platforms for Biomimetic Tissue Engineering

    OpenAIRE

    Torres-Rendon, Jose Guillermo; Femmer, Tim; De Laporte, Laura; Tigges, Thomas; Rahimi, Khoshrow; Gremse, Felix; Zafarnia, Sara; Lederle, Wiltrud; Ifuku, Shinsuke; Wessling, Matthias; Hardy, John G.; Walther, Andreas

    2015-01-01

    A sacrificial templating process using lithographically printed minimal surface structures allows complex de novo geometries of delicate hydrogel materials. The hydrogel scaffolds based on cellulose and chitin nanofibrils show differences in terms of attachment of human mesenchymal stem cells, and allow their differentiation into osteogenic outcomes. The approach here serves as a first example toward designer hydrogel scaffolds viable for biomimetic tissue engineering.

  9. Delivery of enteric neural progenitors with 5-HT4 agonist-loaded nanoparticles and thermosensitive hydrogel enhances cell proliferation and differentiation following transplantation in vivo.

    Science.gov (United States)

    Hotta, Ryo; Cheng, Lily S; Graham, Hannah K; Nagy, Nandor; Belkind-Gerson, Jaime; Mattheolabakis, George; Amiji, Mansoor M; Goldstein, Allan M

    2016-05-01

    Cell therapy offers an innovative approach for treating enteric neuropathies. Postnatal gut-derived enteric neural stem/progenitor cells (ENSCs) represent a potential autologous source, but have a limited capacity for proliferation and neuronal differentiation. Since serotonin (5-HT) promotes enteric neuronal growth during embryonic development, we hypothesized that serotonin receptor agonism would augment growth of neurons from transplanted ENSCs. Postnatal ENSCs were isolated from 2 to 4 week-old mouse colon and cultured with 5-HT4 receptor agonist (RS67506)-loaded liposomal nanoparticles. ENSCs were co-cultured with mouse colon explants in the presence of RS67506-loaded (n = 3) or empty nanoparticles (n = 3). ENSCs were also transplanted into mouse rectum in vivo with RS67506-loaded (n = 8) or blank nanoparticles (n = 4) confined in a thermosensitive hydrogel, Pluronic F-127. Neuronal density and proliferation were analyzed immunohistochemically. Cultured ENSCs gave rise to significantly more neurons in the presence of RS67506-loaded nanoparticles. Similarly, colon explants had significantly increased neuronal density when RS67506-loaded nanoparticles were present. Finally, following in vivo cell delivery, co-transplantation of ENSCs with 5-HT4 receptor agonist-loaded nanoparticles led to significantly increased neuronal density and proliferation. We conclude that optimization of postnatal ENSCs can support their use in cell-based therapies for neurointestinal diseases. PMID:26922325

  10. Multiplexed Dosing Assays by Digitally Definable Hydrogel Volumes

    DEFF Research Database (Denmark)

    Faralli, Adele; Melander, Fredrik; Larsen, Esben Kjær Unmack;

    2016-01-01

    Stable and low-cost multiplexed drug sensitivity assays using small volumes of cells or tissue are in demand for personalized medicine, including patientspecific combination chemotherapy. Spatially defined projected light photopolymerization of hydrogels with embedded active compounds is introduced...

  11. Dye-sensitized solar cells with natural dyes extracted from achiote seeds

    Energy Technology Data Exchange (ETDEWEB)

    Gomez-Ortiz, N.M.; Vazquez-Maldonado, I.A.; Azamar-Barrios, J.A.; Oskam, G. [Departamento de Fisica Aplicada, CINVESTAV-IPN, Merida, Yuc. 97310 (Mexico); Perez-Espadas, A.R.; Mena-Rejon, G.J. [Laboratorio de Quimica Organica de Investigacion, Facultad de Quimica, Universidad Autonoma de Yucatan, Merida, Yuc. 97150 (Mexico)

    2010-01-15

    We have explored the application of natural dyes extracted from the seeds of the achiote shrub (Bixa orellana L.) in dye-sensitized solar cells (DSCs). The main pigments are bixin and norbixin, which were obtained by separation and purification from the dark-red extract (annatto). The dyes were characterized using {sup 1}H-NMR, FTIR spectroscopy, and UV-Vis spectrophotometry. Solar cells were prepared using TiO{sub 2} and ZnO nanostructured, mesoporous films and the annatto, bixin, and norbixin as sensitizers. The best results were obtained with bixin-sensitized TiO{sub 2} solar cells with efficiencies of up to 0.53%, illustrating the importance of purification of dyes from natural extracts. (author)

  12. Quantitative evaluation of regularized phase retrieval algorithms on bone scaffolds seeded with bone cells.

    Science.gov (United States)

    Weber, L; Langer, M; Tavella, S; Ruggiu, A; Peyrin, F

    2016-05-01

    In the field of regenerative medicine, there has been a growing interest in studying the combination of bone scaffolds and cells that can maximize newly formed bone. In-line phase-contrast x-ray tomography was used to image porous bone scaffolds (Skelite(©)), seeded with bone forming cells. This technique allows the quantification of both mineralized and soft tissue, unlike with classical x-ray micro-computed tomography. Phase contrast images were acquired at four distances. The reconstruction is typically performed in two successive steps: phase retrieval and tomographic reconstruction. In this work, different regularization methods were applied to the phase retrieval process. The application of a priori terms for heterogeneous objects enables quantitative 3D imaging of not only bone morphology, mineralization, and soft tissue formation, but also cells trapped in the pre-bone matrix. A statistical study was performed to derive statistically significant information on the different culture conditions. PMID:27054380

  13. Quantitative evaluation of regularized phase retrieval algorithms on bone scaffolds seeded with bone cells

    Science.gov (United States)

    Weber, L.; Langer, M.; Tavella, S.; Ruggiu, A.; Peyrin, F.

    2016-05-01

    In the field of regenerative medicine, there has been a growing interest in studying the combination of bone scaffolds and cells that can maximize newly formed bone. In-line phase-contrast x-ray tomography was used to image porous bone scaffolds (Skelite©), seeded with bone forming cells. This technique allows the quantification of both mineralized and soft tissue, unlike with classical x-ray micro-computed tomography. Phase contrast images were acquired at four distances. The reconstruction is typically performed in two successive steps: phase retrieval and tomographic reconstruction. In this work, different regularization methods were applied to the phase retrieval process. The application of a priori terms for heterogeneous objects enables quantitative 3D imaging of not only bone morphology, mineralization, and soft tissue formation, but also cells trapped in the pre-bone matrix. A statistical study was performed to derive statistically significant information on the different culture conditions.

  14. The influence of hyaluronic acid hydrogel crosslinking density and macromolecular diffusivity on human MSC chondrogenesis and hypertrophy

    OpenAIRE

    Bian, Liming; Hou, Chieh; Tous, Elena; Rai, Reena; Mauck, Robert L.; Burdick, Jason A.

    2012-01-01

    Hyaluronic acid (HA) hydrogels formed via photocrosslinking provide stable 3D hydrogel environments that support the chondrogenesis of mesenchymal stem cells (MSCs). Crosslinking density has a significant impact on the physical properties of hydrogels, including their mechanical stiffness and macromolecular diffusivity. Variations in the HA hydrogel crosslinking density can be obtained by either changes in the HA macromer concentration (1, 3, or 5% w/v at 15 min exposure) or the extent of rea...

  15. Development of Thermosensitive Hydrogels of Chitosan, Sodium and Magnesium Glycerophosphate for Bone Regeneration Applications

    Science.gov (United States)

    Lisková, Jana; Bačaková, Lucie; Skwarczyńska, Agata L.; Musial, Olga; Bliznuk, Vitaliy; De Schamphelaere, Karel; Modrzejewska, Zofia; Douglas, Timothy E.L.

    2015-01-01

    Thermosensitive injectable hydrogels based on chitosan neutralized with sodium beta-glycerophosphate (Na-β-GP) have been studied as biomaterials for drug delivery and tissue regeneration. Magnesium (Mg) has been reported to stimulate adhesion and proliferation of bone forming cells. With the aim of improving the suitability of the aforementioned chitosan hydrogels as materials for bone regeneration, Mg was incorporated by partial substitution of Na-β-GP with magnesium glycerophosphate (Mg-GP). Chitosan/Na-β-GP and chitosan/Na-β-GP/Mg-GP hydrogels were also loaded with the enzyme alkaline phosphatase (ALP) which induces hydrogel mineralization. Hydrogels were characterized physicochemically with respect to mineralizability and gelation kinetics, and biologically with respect to cytocompatibility and cell adhesion. Substitution of Na-β-GP with Mg-GP did not negatively influence mineralizability. Cell biological testing showed that both chitosan/Na-β-GP and chitosan/Na-β-GP/Mg-GP hydrogels were cytocompatible towards MG63 osteoblast-like cells. Hence, chitosan/Na-β-GP/Mg-GP hydrogels can be used as an alternative to chitosan/Na-β-GP hydrogels for bone regeneration applications. However the incorporation of Mg in the hydrogels during hydrogel formation did not bring any appreciable physicochemical or biological benefit. PMID:25859630

  16. Development of Thermosensitive Hydrogels of Chitosan, Sodium and Magnesium Glycerophosphate for Bone Regeneration Applications

    Directory of Open Access Journals (Sweden)

    Jana Lisková

    2015-04-01

    Full Text Available Thermosensitive injectable hydrogels based on chitosan neutralized with sodium beta-glycerophosphate (Na-β-GP have been studied as biomaterials for drug delivery and tissue regeneration. Magnesium (Mg has been reported to stimulate adhesion and proliferation of bone forming cells. With the aim of improving the suitability of the aforementioned chitosan hydrogels as materials for bone regeneration, Mg was incorporated by partial substitution of Na-β-GP with magnesium glycerophosphate (Mg-GP. Chitosan/Na-β-GP and chitosan/Na-β-GP/Mg-GP hydrogels were also loaded with the enzyme alkaline phosphatase (ALP which induces hydrogel mineralization. Hydrogels were characterized physicochemically with respect to mineralizability and gelation kinetics, and biologically with respect to cytocompatibility and cell adhesion. Substitution of Na-β-GP with Mg-GP did not negatively influence mineralizability. Cell biological testing showed that both chitosan/Na-β-GP and chitosan/Na-β-GP/Mg-GP hydrogels were cytocompatible towards MG63 osteoblast-like cells. Hence, chitosan/Na-β-GP/Mg-GP hydrogels can be used as an alternative to chitosan/Na-β-GP hydrogels for bone regeneration applications. However the incorporation of Mg in the hydrogels during hydrogel formation did not bring any appreciable physicochemical or biological benefit.

  17. Double network hydrogel with high mechanical strength:Performance, progress and future perspective

    Institute of Scientific and Technical Information of China (English)

    CHEN YongMei; DONG Kun; LIU ZhenQi; XU Feng

    2012-01-01

    With high water content (~90 wt%) and significantly improved mechanical strength (~MPa),double network (DN) hydrogels have emerged as promising biomaterials with widespread applications in biomedicine.In recent years,DN hydrogels with extremely high mechanical strength have achieved great advance,and scientists have designed a series of natural and biomimetic DN hydrogels with novel functions including low friction,low wear,mechanical anisotropy and cell compatibility.These advances have also led to new design of biocompatible DN hydrogels for regeneration of tissues such as cartilage.In this paper,we reviewed the strategies of designing high-strength DN hydrogel and analyzed the factors that affect DN hydrogel properties.We also discussed the challenges and future development of the DN hydrogel in view of its potential as biomaterials for their biomedical applications.

  18. Use of radiation in the production of hydrogels

    International Nuclear Information System (INIS)

    The first hydrogel for wound dressing processed by radiation left the laboratories in Poland in 1986 by the hands of its inventor Janusz M. Rosiak and soon, after formal tests, arrived in the local market (1992). It was a technological breakthrough due to its product characteristics as pain reliever and enhanced healing properties besides its clever production process combining sterilization and crosslinking in a simultaneous operation. IAEA invited professor Rosiak to support the transference of his technology for many laboratories around the world. The laboratories of developing countries, which face all kinds of restrictions, were seduced by the simplicity of the process and low cost of its raw materials. This was the seed of the flourishing activities in hydrogel dressings in Brazil and other developing countries. The technology transfer of the radiation production of hydrogel dressings and other hydrogels to the Brazilian industry is under way. The usual issues associated with radiation processing arise from this experience, i.e. capital costs, misinformation about radiation and lack of expertise on radiation processing. Some other issues concerning local market and social peculiarities also add to the problem. Notwithstanding, many different opportunities arise from those challenges. These technical and commercial issues are roughly: (i) There are plenty of new hydrogels in the market and all say the same. What else radiation processed hydrogels can say? (ii) Regarding to hydrogels and its industrial production as market product, what are the unique characteristics of radiation processing? It was shown that the radiation is a powerful tool for producing hydrogels the same basic formula with improved flexibility, control and purity

  19. Transcriptome profiling reveals differential expression of interferon family induced by dengue virus 2 in human endothelial cells on tissue culture plastic and polyacrylamide hydrogel.

    Science.gov (United States)

    Pei, Hua; Zuo, Li; Ma, Jing; Cui, Lili; Yu, Fangfang; Lin, Yingzi

    2016-07-01

    A cell model is critical for studying the molecular mechanisms of dengue virus 2 (DENV-2) invasions and cell bioactivity can be easily affected by the substrate matrix. Tissue culture plastic (TCP) and polyacrylamide hydrogel (PAMH) are two kinds of matrices widely used for cells. The effects of different matrices on the cultured cells with DENV-2 invasion remain unknown. To address the issue, the effects of TCP and PAMH were explored in primary human umbilical vein endothelial cells (HUVECs) with DENV-2 invasion. HUVECs were assigned into four groups: group A (cultured on TCP), group B (cultured on PAMH), group C (cultured on TCP with DENV-2 invasion), and group D (cultured on PAMH with DENV-2 invasion). Flow cytometry was performed on HUVECs after 48-hr culture. Gene expression patterns were analyzed by gene microarray. The levels of interleukin-29 (IL-29) were measured by real-time qRT-PCR and ELISA. There were no cell apoptosis induced by DENV-2 in HUVECs cultured on TCP and PAMH (P > 0.05). After DENV-2 invasion, the up-regulated genes involve in the activities of oligoadenylate synthetase (OAS), interferon-related cytokine, and growth factors so on. The up-regulated pathways involve in the responses to DENV-2 and innate immunity. IL-29 was induced in the HUVECs on PAMH when compared with the cells on TCP (P < 0.05). Thus, different matrices cause different immune responses, which should be considered in the cell models for exploring the molecular mechanisms of DENV-induced diseases. J. Med. Virol. 88:1137-1151, 2016. © 2016 Wiley Periodicals, Inc. PMID:27061404

  20. Hydrogels contact lenses

    Czech Academy of Sciences Publication Activity Database

    Michálek, Jiří; Hobzová, Radka; Přádný, Martin; Dušková, Miroslava

    New York : Springer, 2010 - (Ottenbrite, R.; Park, K.; Okano, T.), s. 303-315 ISBN 978-1-4419-5918-8 R&D Projects: GA AV ČR KAN200520804 Institutional research plan: CEZ:AV0Z40500505 Keywords : contact lenses * hydrogels * silicone-hydrogels Subject RIV: EI - Biotechnology ; Bionics http://www.springerlink.com/content/l32kx3303v110unn/

  1. Injectable hyaluronic acid-dextran hydrogels and effects of implantation in ferret vocal fold.

    Science.gov (United States)

    Luo, Ying; Kobler, James B; Heaton, James T; Jia, Xinqiao; Zeitels, Steven M; Langer, Robert

    2010-05-01

    Injectable hydrogels may potentially be used for augmentation/regeneration of the lamina propria of vocal fold tissue. In this study, hyaluronic acid (HA) and dextran were chemically modified and subsequently crosslinked via formation of hydrazone bonds in phosphate buffer. Swelling ratios, degradation, and compressive moduli of the resulting hydrogels were investigated. It was found that the properties of HA-dextran hydrogels were variable and the trend of variation could be correlated with the hydrogel composition. The biocompatibility of three injectable HA-dextran hydrogels with different crosslinking density was assessed in the vocal fold region using a ferret model. It was found that HA-dextran hydrogels implanted for three weeks stimulated mild foreign-body reactions. Distinct tissue-material interactions were also observed for hydrogels made from different formulations: the hydrogel with the lowest crosslinking density was completely degraded in vivo; while material residues were visible for other types of hydrogel injections, with or without cell penetration into the implantation depending on the hydrogel composition. The in vivo results suggest that the HA-dextran hydrogel matrices can be further developed for applications of vocal fold tissue restoration. PMID:20151459

  2. Identification of a Bioactive Compound against Adult T-cell Leukaemia from Bitter Gourd Seeds

    Science.gov (United States)

    Kai, Hisahiro; Akamatsu, Ena; Torii, Eri; Kodama, Hiroko; Yukizaki, Chizuko; Akagi, Isao; Ino, Hisatoshi; Sakakibara, Yoichi; Suiko, Masahito; Yamamoto, Ikuo; Okayama, Akihiko; Morishita, Kazuhiro; Kataoka, Hiroaki; Matsuno, Koji

    2013-01-01

    In our previous report, an 80% ethanol bitter gourd seed extract (BGSE) was found to suppress proliferation of adult T-cell leukemia (ATL) cell lines. The present study aimed to identify the bioactive compounds from BGSE specific against ATL. From the result of an HPLC-MS analysis, α-eleostearic acid (α-ESA) was present in BGSE at 0.68% ± 0.0022% (±SD, n = 5). In the cell proliferation test, α-ESA potently suppressed proliferation of two ATL cell lines (ED and Su9T01; IC50 = 8.9 and 29.3 µM, respectively) more than several other octadecanoic acids. However, α-ESA moderately inhibited phytohemagglutinin-activated human peripheral blood mononuclear cells (PBMC; IC50 = 31.0 µM). These results suggest that BGSE-derived α-ESA has potential as a functional food constituent because of its activity against ATL, particularly against ED cells. Moreover, α-ESA might be effective for the prevention of moderate adverse effects of ATL on normal T cells.

  3. New antifouling silica hydrogel.

    Science.gov (United States)

    Beltrán-Osuna, Ángela A; Cao, Bin; Cheng, Gang; Jana, Sadhan C; Espe, Matthew P; Lama, Bimala

    2012-06-26

    In this work, a new antifouling silica hydrogel was developed for potential biomedical applications. A zwitterionic polymer, poly(carboxybetaine methacrylate) (pCBMA), was produced via atom-transfer radical polymerization and was appended to the hydrogel network in a two-step acid-base-catalyzed sol-gel process. The pCBMA silica aerogels were obtained by drying the hydrogels under supercritical conditions using CO(2). To understand the effect of pCBMA on the gel structure, pCBMA silica aerogels with different pCBMA contents were characterized using scanning electron microscopy (SEM), nuclear magnetic resonance (NMR) spectroscopy, and the surface area from Brauner-Emmet-Teller (BET) measurements. The antifouling property of pCBMA silica hydrogel to resist protein (fibrinogen) adsorption was measured using enzyme-linked immunosorbent assay (ELISA). SEM images revealed that the particle size and porosity of the silica network decreased at low pCBMA content and increased at above 33 wt % of the polymer. The presence of pCBMA increased the surface area of the material by 91% at a polymer content of 25 wt %. NMR results confirmed that pCBMA was incorporated completely into the silica structure at a polymer content below 20 wt %. A protein adsorption test revealed a reduction in fibrinogen adsorption by 83% at 25 wt % pCBMA content in the hydrogel compared to the fibrinogen adsorption in the unmodified silica hydrogel. PMID:22607091

  4. Preparing neural stem/progenitor cells in PuraMatrix hydrogel for transplantation after brain injury in rats: A comparative methodological study.

    Science.gov (United States)

    Aligholi, Hadi; Rezayat, Seyed Mahdi; Azari, Hassan; Ejtemaei Mehr, Shahram; Akbari, Mohammad; Modarres Mousavi, Seyed Mostafa; Attari, Fatemeh; Alipour, Fatemeh; Hassanzadeh, Gholamreza; Gorji, Ali

    2016-07-01

    Cultivation of neural stem/progenitor cells (NS/PCs) in PuraMatrix (PM) hydrogel is an option for stem cell transplantation. The efficacy of a novel method for placing adult rat NS/PCs in PM (injection method) was compared to encapsulation and surface plating approaches. In addition, the efficacy of injection method for transplantation of autologous NS/PCs was studied in a rat model of brain injury. NS/PCs were obtained from the subventricular zone (SVZ) and cultivated without (control) or with scaffold (three-dimensional cultures; 3D). The effect of different approaches on survival, proliferation, and differentiation of NS/PCs were investigated. In in vivo study, brain injury was induced 45 days after NS/PCs were harvested from the SVZ and phosphate buffered saline, PM, NS/PCs, or PM+NS/PCs were injected into the brain lesion. There was an increase in cell viability and proliferation after injection and surface plating of NS/PCs compared to encapsulation and neural differentiation markers were expressed seven days after culturing the cells. Using injection method, transplantation of NS/PCs cultured in PM resulted in significant reduction of lesion volume, improvement of neurological deficits, and enhancement of surviving cells. In addition, the transplanted cells could differentiate in to neurons, astrocytes, or oligodendrocytes. Our results indicate that the injection and surface plating methods enhanced cell survival and proliferation of NS/PCs and suggest the injection method as a promising approach for transplantation of NS/PCs in brain injury. PMID:27038753

  5. Bone marrow derived cell-seeded extracellular matrix: A novel biomaterial in the field of wound management

    Directory of Open Access Journals (Sweden)

    V. Remya

    2014-11-01

    Full Text Available Aim: Extensive or irreversible damage to the skin often requires additional skin substitutes for reconstruction. Biomaterials have become critical components in the development of effective new medical therapies for wound care. Materials and Methods: In the present study, a cell matrix construct (bone marrow-derived cells (BMdc seeded extracellular matrix [ECM] was used as a biological substitute for the repair of full-thickness skin wound. ECM was developed by decellularizing fish swim bladder (FSB. Goat bone marrow-derived cells (G-BMdc were seeded over this decellularized matrix. Efficacy of this cell matrix construct in wound repair was tested by implanting it over 20 mm2 × 20 mm2 size fullthickness skin wound created over the dorsum of rat. The study was conducted in 16 clinically healthy adult rats of either sex. The animals were randomly divided into 2 equal groups of 8 animals each. In Group I, animal’s wounds were repaired with a cellular FSB matrix. In Group II, wounds were repaired with G-BMdc seeded a cellular FSB matrix. Immune response and efficacy of healing were analyzed. Results: Quality of healing and immuno tolerance to the biological substitute was significantly better in Group II than Group I. Conclusion: Seeding with BMdc increases the wound healing potency and modulates the immune response to a significantly negligible level. The BMdc seeded acellular FSB matrix was found to be a novel biomaterial for wound management.

  6. Inhibitory potential of rambutan seeds extract and fractions on adipogenesis in 3T3-L1 cell line

    Directory of Open Access Journals (Sweden)

    Sylvia Soeng

    2015-03-01

    Full Text Available Objective: Type 2 diabetes is a global health problem with increasing prevalence related to several conditions; one of these is due to obesity. Rambutan (Nephelium lappaceum L seeds contain various phenolic compounds. The present study was designed to evaluate the phytochemical content and the inhibitory potential of rambutan seeds extract and fractions on glucose-6-phosphate dehydrogenase (G6PDH, and #945;-glucosidase, and triglyceride activities ex vivo in 3T3-L1 cell line (pre-adipocytes for an antidiabetic and antidiapogenesis agent screening. Methods: Phytochemical analysis was performed using modified Farnsworth method. Cytotoxicity or cell viability of rambutan seed extracts (distillated ethanol 70% and fractions (hexane, ethyl acetate, butanol and water fractions were assayed using MTS (3-(4,5-dimethylthiazol-2-yl-5-(3-carboxymethoxyphenyl-2-(4-sulfophenyl-2H-tetrazolium assay. Triglyceride (TG level, G6PDH and and #945;-glucosidase acitivity and inhibitory activities were determined by commercial assay kits. Results: Extract and fractions of rambutan seed contained alkaloid, terpenoid, triterpenoid and phenol; flavonoid, tannin, saponin and steroid were undetected. The lowest cytotoxic activity and safe substances on 3T3-L1 cell were rambutan seed extract and hexane fraction. Rambutan seed extract at the dose of 50 and micro;g/ml was the most active to lower G6PDH and and #945;-glucosidase as well as TG level. Conclusion: Rambutan seed extract and hexane fraction have the phytochemical bioactive content to posses inhibitory potential on G6PDH and and #945;-glucosidase as well as TG level in the present experimental set of 3T3-L1 cell lines. [J Exp Integr Med 2015; 5(1.000: 55-60

  7. Injectable osteogenic and angiogenic nanocomposite hydrogels for irregular bone defects.

    Science.gov (United States)

    Vishnu Priya, M; Sivshanmugam, A; Boccaccini, A R; Goudouri, O M; Sun, Wook; Hwang, Nathaniel; Deepthi, S; Nair, Shantikumar V; Jayakumar, R

    2016-01-01

    Injectable hydrogels with their 3D structure and good moldability serve as excellent scaffolding material for regenerating irregular non load-bearing bone defects. Most of the bone defects do not heal completely due to the lack of vasculature required for the transport of nutrients and oxygen to the regenerating tissues. To enhance vasculature, we developed an injectable hydrogel system made of chitin and poly (butylene succinate) (PBSu) loaded with 250  ±  20 nm sized fibrin nanoparticles (FNPs) and magnesium-doped bioglass (MBG). FNPs were expected to enhance vascularisation and MBG was expected to help induce early osteogenesis. Composite hydrogels were analysed using Fourier transform infra-red spectroscopy, scanning electron microscopy (SEM), energy dispersive x-ray spectroscopy, and rheology. Hydrogels with MBG showed a slightly rougher morphology upon SEM analysis. Composites containing 5% MBG and 2% FNPs showed good rheological properties, injectability, temperature stability, biomineralization and protein adsorption. Human umbilical vein endothelial cells (HUVECs) and rabbit-adipose derived mesenchymal stem cells (rASCs) were used for cyto-compatibility studies. Composite gels with 2% FNPs and 2% MBG (composite 1) were considered to be non-toxic to both the cells and were taken for further in vitro studies. Aortic ring assay was carried out to study the angiogenic potential of the hydrogels. The aorta placed with composite hydrogels showed enhanced sprouting of blood vessels. rASCs too showed good spreading on the composite hydrogels. Hydrogels containing MBG showed early initiation of differentiation and higher expression of alkaline phosphatase and osteocalcin confirming the osteoinductive property of MBG. These studies indicate that this composite hydrogel can be used for regenerating irregular bone defects. PMID:27305426

  8. Enhanced performance of flexible nanocrystalline silicon thin-film solar cells using seed layers with high hydrogen dilution.

    Science.gov (United States)

    Lee, Ji-Eun; Kim, Donghwan; Yoon, Kyung Hoon; Cho, Jun-Sik

    2013-12-01

    Flexible hydrogenated nanocrystalline (nc-Si:H) thin-film solar cells were prepared by very high frequency plasma enhanced chemical vapor deposition (VHF-PECVD), and the effect of highly crystalline intrinsic Si seed layers at the initial growth stage of i nc-Si:H absorbers on their structural and electrical properties and on the performance of solar cells was investigated. The crystallization of i nc-Si:H absorbers was significantly enforced by the introduction of highly crystalline seed layers, resulting in the reduction of defect-dense a-Si:H grain boundary and incubation layer thickness. The open circuit voltage of the nc-Si:H solar cells with the seed layers was improved by the decrease of charged defect density in the defect-rich amorphous region. PMID:24266159

  9. Catalysis of Supramolecular Hydrogelation.

    Science.gov (United States)

    Trausel, Fanny; Versluis, Frank; Maity, Chandan; Poolman, Jos M; Lovrak, Matija; van Esch, Jan H; Eelkema, Rienk

    2016-07-19

    One often thinks of catalysts as chemical tools to accelerate a reaction or to have a reaction run under more benign conditions. As such, catalysis has a role to play in the chemical industry and in lab scale synthesis that is not to be underestimated. Still, the role of catalysis in living systems (cells, organisms) is much more extensive, ranging from the formation and breakdown of small molecules and biopolymers to controlling signal transduction cascades and feedback processes, motility, and mechanical action. Such phenomena are only recently starting to receive attention in synthetic materials and chemical systems. "Smart" soft materials could find many important applications ranging from personalized therapeutics to soft robotics to name but a few. Until recently, approaches to control the properties of such materials were largely dominated by thermodynamics, for instance, looking at phase behavior and interaction strength. However, kinetics plays a large role in determining the behavior of such soft materials, for instance, in the formation of kinetically trapped (metastable) states or the dynamics of component exchange. As catalysts can change the rate of a chemical reaction, catalysis could be used to control the formation, dynamics, and fate of supramolecular structures when the molecules making up these structures contain chemical bonds whose formation or exchange are susceptible to catalysis. In this Account, we describe our efforts to use synthetic catalysts to control the properties of supramolecular hydrogels. Building on the concept of synthesizing the assembling molecule in the self-assembly medium from nonassembling precursors, we will introduce the use of catalysis to change the kinetics of assembler formation and thereby the properties of the resulting material. In particular, we will focus on the synthesis of supramolecular hydrogels where the use of a catalyst provides access to gel materials with vastly different appearance and mechanical

  10. Ionically cross-linked alginate hydrogels as tissue engineering scaffolds

    Science.gov (United States)

    Kuo, Catherine Kyleen

    Generation of living tissues through tissue engineering can be achieved via incorporation of cells into synthetic scaffolds designed to facilitate new tissue formation. Necessary characteristics of a scaffold include biocompatibility, high porosity with controllable pore size and interconnectivity, moldability, chemical and mechanical stability, and structural homogeneity. Hydrogels often possess many of the necessary characteristics and thus are favorable candidates for scaffolding. Alginate hydrogels are commonly made by ionically crosslinking with calcium ions from CaCl2 or CaSO4. These hydrogels are favored for their mild gel formation, however the gelation rate is rapid and uncontrollable (fast-gelation), resulting in varying crosslinking density throughout the gel. In this work, structurally homogeneous calcium alginate hydrogels were formed via a slow-gelation system that utilizes uniform mixing of CaCO3 with sodium alginate solution, and the addition of slowly hydrolyzing D-gluconic acid lactone to slowly release calcium ions for crosslinking. Homogeneity and mechanical properties of these hydrogels were shown to be superior to those of fast-gelled hydrogels. Gelation rate was controlled through the incorporation of CaSO4, and by varying total calcium content, polymer concentration and gelation temperature. Control over mechanical properties and diffusivity was demonstrated in the homogeneous hydrogels by adjusting compositional variables. Consistent control over solute diffusivity through gel discs reflected the structural homogeneity of the gels. To overcome the instability of ionically crosslinked gels in tissue culture medium, a method was developed to control the hydrogel dimensions by adjusting the ionic concentration of the medium. Stability of the hydrogels in this controlled environment was characterized through swelling experiments and mechanical testing. To provide for scaffold degradation and thereby promote tissue growth, alginate lyase was

  11. The Flocculating Cationic Polypetide from Moringa oleifera Seeds Damages Bacterial Cell Membranes by Causing Membrane Fusion.

    Science.gov (United States)

    Shebek, Kevin; Schantz, Allen B; Sines, Ian; Lauser, Kathleen; Velegol, Stephanie; Kumar, Manish

    2015-04-21

    A cationic protein isolated from the seeds of the Moringa oleifera tree has been extensively studied for use in water treatment in developing countries and has been proposed for use in antimicrobial and therapeutic applications. However, the molecular basis for the antimicrobial action of this peptide, Moringa oleifera cationic protein (MOCP), has not been previously elucidated. We demonstrate here that a dominant mechanism of MOCP antimicrobial activity is membrane fusion. We used a combination of cryogenic electron microscopy (cryo-EM) and fluorescence assays to observe and study the kinetics of fusion of membranes in liposomes representing model microbial cells. We also conducted cryo-EM experiments on E. coli cells where MOCP was seen to fuse the inner and outer membranes. Coarse-grained molecular dynamics simulations of membrane vesicles with MOCP molecules were used to elucidate steps in peptide adsorption, stalk formation, and fusion between membranes. PMID:25845029

  12. The healing of bony defects by cell-free collagen-based scaffolds compared to stem cell-seeded tissue engineered constructs.

    LENUS (Irish Health Repository)

    Lyons, Frank G

    2010-12-01

    One of the key challenges in tissue engineering is to understand the host response to scaffolds and engineered constructs. We present a study in which two collagen-based scaffolds developed for bone repair: a collagen-glycosaminoglycan (CG) and biomimetic collagen-calcium phosphate (CCP) scaffold, are evaluated in rat cranial defects, both cell-free and when cultured with MSCs prior to implantation. The results demonstrate that both cell-free scaffolds showed excellent healing relative to the empty defect controls and somewhat surprisingly, to the tissue engineered (MSC-seeded) constructs. Immunological analysis of the healing response showed higher M1 macrophage activity in the cell-seeded scaffolds. However, when the M2 macrophage response was analysed, both groups (MSC-seeded and non-seeded scaffolds) showed significant activity of these cells which are associated with an immunomodulatory and tissue remodelling response. Interestingly, the location of this response was confined to the construct periphery, where a capsule had formed, in the MSC-seeded groups as opposed to areas of new bone formation in the non-seeded groups. This suggests that matrix deposited by MSCs during in vitro culture may adversely affect healing by acting as a barrier to macrophage-led remodelling when implanted in vivo. This study thus improves our understanding of host response in bone tissue engineering.

  13. PVA-Sago starch hydrogel and the preliminary clinical animal study of the hydrogel

    Energy Technology Data Exchange (ETDEWEB)

    Hashim, Kamaruddin; Mohd Dahlan, Khairul Zaman [Malaysian Institute for Nuclear Technology Research, Bangi, Kajang (Malaysia); Halim, Ahmad Sukari; Md Nor, Mohd Tarmizi [Sciences University of Malaysia, School of Medical Sciences, Kerian, Kelantan (Malaysia); Yoshii, Fumio [Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Chemistry Research Establishment

    2002-03-01

    Sago starch granule dissolves in hot water to form physically crosslink semi-gel structure. Polyvinyl alcohol (PVA) in aqueous solution is chemically crosslink and form hydrogel after expose to gamma or electron beam irradiation. Combination of sago starch and PVA give tremendous improvement on strength and elasticity of the gel. Adding additive such as carboxymethyl cellulose enhance the swelling or absorption property of the gel. These properties of hydrogel are important for wound dressing application. The preliminary clinical animal study on the PVA Sago hydrogel dressing shows promising results of healing process in comparison with the conventional dressing using vaseline impregnated gauze acting as control dressing. This re-confirmed by biopsy tests on the wound tissue taking during the healing process. The tests show the increasing amount of fibroblast and endothelial cells on both wounds using hydrogel and jalonet during the healing process. Also, the rate of epitheliazation is almost completed for both wounds after 10 days of dressing and the lymphocytes cell increase tremendously for the first 14 days with hydrogel dressing. (author)

  14. PVA-Sago starch hydrogel and the preliminary clinical animal study of the hydrogel

    International Nuclear Information System (INIS)

    Sago starch granule dissolves in hot water to form physically crosslink semi-gel structure. Polyvinyl alcohol (PVA) in aqueous solution is chemically crosslink and form hydrogel after expose to gamma or electron beam irradiation. Combination of sago starch and PVA give tremendous improvement on strength and elasticity of the gel. Adding additive such as carboxymethyl cellulose enhance the swelling or absorption property of the gel. These properties of hydrogel are important for wound dressing application. The preliminary clinical animal study on the PVA Sago hydrogel dressing shows promising results of healing process in comparison with the conventional dressing using vaseline impregnated gauze acting as control dressing. This re-confirmed by biopsy tests on the wound tissue taking during the healing process. The tests show the increasing amount of fibroblast and endothelial cells on both wounds using hydrogel and jalonet during the healing process. Also, the rate of epitheliazation is almost completed for both wounds after 10 days of dressing and the lymphocytes cell increase tremendously for the first 14 days with hydrogel dressing. (author)

  15. Template-synthesized opal hydrogels

    Institute of Scientific and Technical Information of China (English)

    LI Jun; JI Lijun; RONG Jianhua; YANG Zhenzhong

    2003-01-01

    Opal hydrogels could be synthesized with polymer inverse opal template. A pH responsive opal N-iso- propylacrylamide/acrylic acid copolymerized hydrogel was prepared as an example. The ordered structure and response to pH were investigated. Through the sol-gel process of tetrabutyl titanate, opal titania was obtained with the opal hydrogel template.

  16. HLC/pullulan and pullulan hydrogels: their microstructure, engineering process and biocompatibility.

    Science.gov (United States)

    Li, Xian; Xue, Wenjiao; Liu, Yannan; Li, Weina; Fan, Daidi; Zhu, Chenhui; Wang, Yaoyu

    2016-01-01

    New locally injectable biomaterials that are suitable for use as soft tissue fillers are needed to address a significant unmet medical need. In this study, we used pullulan and human-like collagen (HLC) based hydrogels with various molecular weights (MWs) in combination therapy against tissue defects. Briefly, pullulan was crosslinked with NaIO4 to form a pullulan hydrogel and then may coupled with HLC using the reaction between the -NH2 end-group of HLC and the -CHO group present on the aldehyde pullulan to form the HLC/pullulan hydrogel, wherein the NaIO4 acted as the crosslinking and oxidizing agent. The good miscibility of pullulan and HLC in the hydrogels was confirmed via Fourier transform infrared spectroscopy, scanning electron microscopy, compression testing, enzyme degradation testing, cell adhesions, live/dead staining and subcutaneous filling assays. Here, pullulan hydrogels with various MWs were fabricated and physicochemically characterized. Limitations of the pullulan hydrogels included inflammation, poor mechanical strength, and degradation. By contrast, the properties of the HLC/pullulan hydrogels strongly enhanced. The efficacy of these hydrogels was evaluated both in vitro and in vivo. Our results indicate that HLC/pullulan hydrogels may have therapeutic value as efficient soft tissue fillers, with reduced inflammation, improved cell adhesion and delayed hydrogel degradation. PMID:26478402

  17. Bioactive Nanocomposite Poly (Ethylene Glycol) Hydrogels Crosslinked by Multifunctional Layered Double Hydroxides Nanocrosslinkers.

    Science.gov (United States)

    Huang, Heqin; Xu, Jianbin; Wei, Kongchang; Xu, Yang J; Choi, Chun Kit K; Zhu, Meiling; Bian, Liming

    2016-07-01

    Poly (ethylene glycol) (PEG) based hydrogels have been widely used in many biomedical applications such as regenerative medicine due to their good biocompatibility and negligible immunogenicity. However, bioactivation of PEG hydrogels, such as conjugation of bioactive biomolecules, is usually necessary for cell-related applications. Such biofunctionalization of PEG hydrogels generally involves complicated and time-consuming bioconjugation procedures. Herein, we describe the facile preparation of bioactive nanocomposite PEG hydrogel crosslinked by the novel multifunctional nanocrosslinkers, namely polydopamine-coated layered double hydroxides (PD-LDHs). The catechol-rich PD-LDH nanosheets not only act as effective nanocrosslinkers reinforcing the mechanical strength of the hydrogel, but also afford the hydrogels with robust bioactivity and bioadhesion via the cortical-mediated couplings. The obtained nanocomposite PEG hydrogels with the multifunctional PD-LDH crosslinking domains show tunable mechanical properties, self-healing ability, and bioadhesion to biological tissues. Furthermore, these hydrogels also promote the sequestration of proteins and support the osteogenic differentiation of human mesenchymal stem cells without any further bio-functionalization. Such facile preparation of bioactive and bioadhesive PEG hydrogels have rarely been achieved and may open up a new avenue for the design of nanocomposite PEG hydrogels for biomedical applications. PMID:27061462

  18. Anti-inflammatory drug delivery from hyaluronic acid hydrogels.

    Science.gov (United States)

    Hahn, Sei K; Jelacic, Sandra; Maier, Ronald V; Stayton, Patrick S; Hoffman, Allan S

    2004-01-01

    Two different types of hyaluronic acid (HA) hydrogels were synthesized by crosslinking HA with divinyl sulfone (DVS) and poly(ethylene glycol)-divinyl sulfone (VS-PEG-VS). Vitamin E succinate (VES), an anti-inflammatory drug, and bovine serum albumin (BSA), a model of anti-inflammatory protein drugs, were loaded into the gels and their release kinetics were measured in vitro. VES and BSA released with a burst from both HA hydrogels during the first few hours, and release continued gradually for several days. The rate of release from HA-VS-PEG-VS-HA hydrogels was faster than that from HA-DVS-HA hydrogels, presumably due to the lower crosslink density in the former. The anti-inflammatory action of released VES was tested by incubating peripheral blood mononuclear cells (PBMC) on HA hydrogels with and without VES in the gel. The number of cells adhering on HA hydrogels was very low compared to that on tissue culture polystyrene (TCPS), which might be one of the important advantages of using HA hydrogels for implant coatings or tissue engineering applications. ELISA test results showed that the tumor necrosis factor-alpha (TNF-alpha) concentration was very low in the supernatant of the wells containing the HA hydrogel with VES in contact with the activated macrophages compared to that without VES. This is probably the effect of the released VES reducing the production of anti-inflammatory cytokine, TNF-alpha. HA hydrogels containing anti-inflammatory drugs may have potential for use in tissue engineering and also as biocompatible coatings of implants. PMID:15503629

  19. Gelatin- and starch-based hydrogels. Part A: Hydrogel development, characterization and coating.

    Science.gov (United States)

    Van Nieuwenhove, Ine; Salamon, Achim; Peters, Kirsten; Graulus, Geert-Jan; Martins, José C; Frankel, Daniel; Kersemans, Ken; De Vos, Filip; Van Vlierberghe, Sandra; Dubruel, Peter

    2016-11-01

    The present work aims at constructing the ideal scaffold matrix of which the physico-chemical properties can be altered according to the targeted tissue regeneration application. Ideally, this scaffold should resemble the natural extracellular matrix (ECM) as close as possible both in terms of chemical composition and mechanical properties. Therefore, hydrogel films were developed consisting of methacrylamide-modified gelatin and starch-pentenoate building blocks because the ECM can be considered as a crosslinked hydrogel network consisting of both polysaccharides and structural, signaling and cell-adhesive proteins. For the gelatin hydrogels, three different substitution degrees were evaluated including 31%, 72% and 95%. A substitution degree of 32% was applied for the starch-pentenoate building block. Pure gelatin hydrogels films as well as interpenetrating networks with gelatin and starch were developed. Subsequently, these films were characterized using gel fraction and swelling experiments, high resolution-magic angle spinning (1)H NMR spectroscopy, rheology, infrared mapping and atomic force microscopy. The results indicate that both the mechanical properties and the swelling extent of the developed hydrogel films can be controlled by varying the chemical composition and the degree of substitution of the methacrylamide-modified gelatin applied. The storage moduli of the developed materials ranged between 14 and 63kPa. Phase separation was observed for the IPNs for which separated starch domains could be distinguished located in the surrounding gelatin matrix. Furthermore, we evaluated the affinity of aggrecan for gelatin by atomic force microscopy and radiolabeling experiments. We found that aggrecan can be applied as a bioactive coating for gelatin hydrogels by a straightforward physisorption procedure. Thus, we achieved distinct fine-tuning of the physico-chemical properties of these hydrogels which render them promising candidates for tissue engineering

  20. Induction of Angiogenesis by Matrigel Coating of VEGF-Loaded PEG/PCL-Based Hydrogel Scaffolds for hBMSC Transplantation.

    Science.gov (United States)

    Jung, Yeon Joo; Kim, Kyung-Chul; Heo, Jun-Young; Jing, Kaipeng; Lee, Kyung Eun; Hwang, Jun Seok; Lim, Kyu; Jo, Deog-Yeon; Ahn, Jae Pyoung; Kim, Jin-Man; Huh, Kang Moo; Park, Jong-Il

    2015-07-01

    hBMSCs are multipotent cells that are useful for tissue regeneration to treat degenerative diseases and others for their differentiation ability into chondrocytes, osteoblasts, adipocytes, hepatocytes and neuronal cells. In this study, biodegradable elastic hydrogels consisting of hydrophilic poly(ethylene glycol) (PEG) and hydrophobic poly(ε-caprolactone) (PCL) scaffolds were evaluated for tissue engineering because of its biocompatibility and the ability to control the release of bioactive peptides. The primary cultured cells from human bone marrow are confirmed as hBMSC by immunohistochemical analysis. Mesenchymal stem cell markers (collagen type I, fibronectin, CD54, integrin1β, and Hu protein) were shown to be positive, while hematopoietic stem cell markers (CD14 and CD45) were shown to be negative. Three different hydrogel scaffolds with different block compositions (PEG:PCL=6:14 and 14:6 by weight) were fabricated using the salt leaching method. The hBMSCs were expanded, seeded on the scaffolds, and cultured up to 8 days under static conditions in Iscove's Modified Dulbecco's Media (IMDM). The growth of MSCs cultured on the hydrogel with PEG/PCL= 6/14 was faster than that of the others. In addition, the morphology of MSCs seemed to be normal and no cytotoxicity was found. The coating of the vascular endothelial growth factor (VEGF) containing scaffold with Matrigel slowed down the release of VEGF in vitro and promoted the angiogenesis when transplanted into BALB/c nude mice. These results suggest that hBMSCs can be supported by a biode gradable hydrogel scaffold for effective cell growth, and enhance the angiogenesis by Matrigel coating. PMID:26159216

  1. Can retinal ganglion cell dipoles seed iso-orientation domains in the visual cortex?

    Directory of Open Access Journals (Sweden)

    Manuel Schottdorf

    Full Text Available It has been argued that the emergence of roughly periodic orientation preference maps (OPMs in the primary visual cortex (V1 of carnivores and primates can be explained by a so-called statistical connectivity model. This model assumes that input to V1 neurons is dominated by feed-forward projections originating from a small set of retinal ganglion cells (RGCs. The typical spacing between adjacent cortical orientation columns preferring the same orientation then arises via Moiré-Interference between hexagonal ON/OFF RGC mosaics. While this Moiré-Interference critically depends on long-range hexagonal order within the RGC mosaics, a recent statistical analysis of RGC receptive field positions found no evidence for such long-range positional order. Hexagonal order may be only one of several ways to obtain spatially repetitive OPMs in the statistical connectivity model. Here, we investigate a more general requirement on the spatial structure of RGC mosaics that can seed the emergence of spatially repetitive cortical OPMs, namely that angular correlations between so-called RGC dipoles exhibit a spatial structure similar to that of OPM autocorrelation functions. Both in cat beta cell mosaics as well as primate parasol receptive field mosaics we find that RGC dipole angles are spatially uncorrelated. To help assess the level of these correlations, we introduce a novel point process that generates mosaics with realistic nearest neighbor statistics and a tunable degree of spatial correlations of dipole angles. Using this process, we show that given the size of available data sets, the presence of even weak angular correlations in the data is very unlikely. We conclude that the layout of ON/OFF ganglion cell mosaics lacks the spatial structure necessary to seed iso-orientation domains in the primary visual cortex.

  2. Vapor of volatile oils from Litsea cubeba seed induces apoptosis and causes cell cycle arrest in lung cancer cells.

    Directory of Open Access Journals (Sweden)

    Soma Seal

    Full Text Available Non-small cell lung carcinoma (NSCLC is a major killer in cancer related human death. Its therapeutic intervention requires superior efficient molecule(s as it often becomes resistant to present chemotherapy options. Here we report that vapor of volatile oil compounds obtained from Litsea cubeba seeds killed human NSCLC cells, A549, through the induction of apoptosis and cell cycle arrest. Vapor generated from the combined oils (VCO deactivated Akt, a key player in cancer cell survival and proliferation. Interestingly VCO dephosphorylated Akt at both Ser(473 and Thr(308; through the suppression of mTOR and pPDK1 respectively. As a consequence of this, diminished phosphorylation of Bad occurred along with the decreased Bcl-xL expression. This subsequently enhanced Bax levels permitting the release of mitochondrial cytochrome c into the cytosol which concomitantly activated caspase 9 and caspase 3 resulting apoptotic cell death. Impairment of Akt activation by VCO also deactivated Mdm2 that effected overexpression of p53 which in turn upregulated p21 expression. This causes enhanced p21 binding to cyclin D1 that halted G1 to S phase progression. Taken together, VCO produces two prong effects on lung cancer cells, it induces apoptosis and blocked cancer cell proliferation, both occurred due to the deactivation of Akt. In addition, it has another crucial advantage: VCO could be directly delivered to lung cancer tissue through inhalation.

  3. Self-Healing Elastin-Bioglass Hydrogels.

    Science.gov (United States)

    Zeng, Qiongyu; Desai, Malav S; Jin, Hyo-Eon; Lee, Ju Hun; Chang, Jiang; Lee, Seung-Wuk

    2016-08-01

    Tailorable hydrogels that are mechanically robust, injectable, and self-healable, are useful for many biomedical applications including tissue repair and drug delivery. Here we use biological and chemical engineering approaches to develop a novel in situ forming organic/inorganic composite hydrogel with dynamic aldimine cross-links using elastin-like polypeptides (ELP) and bioglass (BG). The resulting ELP/BG biocomposites exhibit tunable gelling behavior and mechanical characteristics in a composition and concentration dependent manner. We also demonstrate self-healing in the ELP/BG hydrogels by successfully reattaching severed pieces as well as through rheology. In addition, we show the strength of genetic engineering to easily customize ELP by fusing cell-stimulating "RGD" peptide motifs. We showed that the resulting composite materials are cytocompatible as they support the cellular growth and attachment. Our robust in situ forming ELP/BG composite hydrogels will be useful as injectable scaffolds for delivering cell and drug molecules to promote soft tissue regeneration in the future. PMID:27380227

  4. Evaluation of early healing events around mesenchymal stem cell-seeded collagen-glycosaminoglycan scaffold. An experimental study in Wistar rats.

    LENUS (Irish Health Repository)

    Alhag, Mohamed

    2011-03-01

    Tissue engineering using cell-seeded biodegradable scaffolds offers a new bone regenerative approach that might circumvent many of the limitations of current therapeutic modalities. The aim of this experiment was to study the early healing events around mesenchymal stem cell-seeded collagen-glycosaminoglycan scaffolds.

  5. Optimizing cell seeding and retention in a three-dimensional bioengineered cardiac ventricle: The two-stage cellularization model.

    Science.gov (United States)

    Patel, Nikita M; Yazdi, Iman K; Tasciotti, Ennio; Birla, Ravi K

    2016-10-01

    Current cell seeding techniques focus on passively directing cells to a scaffold surface with the addition of dynamic culture to encourage cell permeation. In 3D tissue engineered constructs, cell retention efficiency is dependent on the cell delivery method, and biomaterial properties. Passive cell delivery relies on cell migration to the scaffold surface; biomaterial surface properties and porosity determine cell infiltration capacity. As a result, cell retention efficiencies remain low. The development of an effective two-stage cell seeding technique, coupled with perfusion culture, provides the potential to improve cellularization efficiency, and retention. This study, uses a chitosan bioengineered open ventricle (BEOV) scaffold to produce a two-stage perfusion cultured ventricle (TPCV). TPCV were fabricated by direct injection of 10 million primary rat neonatal cardiac cells, followed by wrapping of the outer scaffold surface with a 3D fibrin gel artificial heart muscle patch; TPCV were perfusion cultured for 3 days. The average biopotential output was 1.731 mV. TPCV cell retention following culture was approximately 5%. Cardiac cells were deposited on the scaffold surface and formed intercellular connections. Histological assessment displayed localized cell clusters, with some dissemination, and validated the observed presence of intercellular and gap-junction interactions. The study demonstrates initial effectiveness of our two-stage cell delivery concept, based on function and biological metrics. Biotechnol. Bioeng. 2016;113: 2275-2285. © 2016 Wiley Periodicals, Inc. PMID:27071026

  6. Chemically cross-linked silk fibroin hydrogel with enhanced elastic properties, biodegradability, and biocompatibility

    Directory of Open Access Journals (Sweden)

    Kim MH

    2016-06-01

    Full Text Available Min Hee Kim, Won Ho Park Department of Advanced Organic Materials and Textile Engineering System, Chungnam National University, Daejeon, Korea Abstract: In this study, the synthesis of silk fibroin (SF hydrogel via chemical cross-linking reactions of SF due to gamma-ray (γ-ray irradiation was investigated, as were the resultant hydrogel’s properties. Two different hydrogels were investigated: physically cross-linked SF hydrogel and chemically cross-linked SF hydrogel irradiated at different doses of γ-rays. The effects of the irradiation dose and SF concentration on the hydrogelation of SF were examined. The chemically cross-linked SF hydrogel was compared with the physically cross-linked one with regard to secondary structure and gel strength. Furthermore, the swelling behavior, crystallinity, and biodegradation of the SF hydrogels were characterized. To assay cell proliferation, the cell viability of human mesenchymal stem cells on the lyophilized SF hydrogel scaffolds was evaluated, and no significant cytotoxicity against human mesenchymal stem cells was observed. Keywords: silk fibroin, hydrogels, biodegradation rate, gamma irradiation, cross-linking

  7. Radioactive 125I seeds inhibit cell growth and epithelial-mesenchymal transition in human glioblastoma multiforme via a ROS-mediated signaling pathway

    International Nuclear Information System (INIS)

    Glioblastoma multiforme (GBM) is the most common primary central nervous system neoplasm in adults. Radioactive 125I seed implantation has been widely applied in the treatment of cancers. Moreover, previous clinical trials have confirmed that 125I seeds treatment was an effective therapy in GBM. We sought to investigate the effect of 125I seed on GBM cell growth and Epithelial-mesenchymal transition (EMT). Cells were exposed to irradiation at different doses. Colony-formation assay, EdU assay, cell cycle analysis, and TUNEL assay were preformed to investigate the radiation sensitivity. The effects of 125I seeds irradiation on EMT were measured by transwell, Boyden and wound-healing assays. The levels of reactive oxygen species (ROS) were measured by DCF-DA assay. Moreover, the radiation sensitivity and EMT were investigated with or without pretreatment with glutathione. Additionally, nude mice with tumors were measured after treated with radiation. Radioactive 125I seeds are more effective than X-ray irradiation in inhibiting GBM cell growth. Moreover, EMT was effectively inhibited by 125I seed irradiation. A mechanism study indicated that GBM cell growth and EMT inhibition were induced by 125I seeds with the involvement of a ROS-mediated signaling pathway. Radioactive 125I seeds exhibit novel anticancer activity via a ROS-mediated signaling pathway. These findings have clinical implications for the treatment of patients with GBM by 125I seeds

  8. Effect of standard and reversible arrangements of Ph.Eur./USP extraction cells during dissolution tests of calcium dobesilate in hydrogel formulation

    Directory of Open Access Journals (Sweden)

    Lisik Anna

    2015-06-01

    Full Text Available The aim of the study was to evaluate, in comparison to the reference product, the effect of the hydrophilic nonionic polymers: methylcellulose (MC and hydroxypropyl methylcellulose (HPMC, as well as the anionic polymers - copolymers of acrylic acid, on the release kinetics of a calcium dobesilate hydrogel formulation intended for application on the skin. In this work, we used an ointment cell for the release of the active pharmaceutical ingredient (API from the formulations. This release was performed by employing the paddle method at 100 rpm, with the extraction cells placed in the release vessels in two different positions: with the semipermeable membrane faced to the top, or to the bottom of the vessel. Released API percentage was assessed via the validated spectrophotometric method. In the study with standard placement of the ointment cell, the release rates ranged from 4.45×10-3 min-1 for a formulation containing polyacrylic acid (PA, to 6.96 × 10-3 min-1 for a formulation based on HPMC. In the group of nonionic polymers, the release rate is higher in the case of HPMC, and lower in the case of MC. In the group of anionic polymers, the release rate is higher with the formulation of a modified copolymer of acrylic acid 11 (PC11, while release from a formulation comprising a polymer PA is rather prolonged. We found that the placement of the extraction cell does not affect the alignment of the formulations investigated in terms of the release rates in the group of non-ionic formulations: HPMC > MC, and in the group of preparation of ionic polymers: PC11 > PA.

  9. Astrocytes alignment and reactivity on collagen hydrogels patterned with ECM proteins

    OpenAIRE

    Hsiao, Tony W.; Tresco, Patrick A.; Hlady, Vladimir

    2014-01-01

    To modulate the surface properties of collagen and subsequent cell-surface interactions, a method was developed to transfer protein patterns from glass coverslips to collagen type I hydrogel surfaces. Two proteins and one proteoglycan found in central nervous system extracellular matrix as well as fibrinogen were patterned in stripes onto collagen hydrogel and astrocytes were cultured on these surfaces. The addition of the stripe protein patterns to hydrogels created astrocyte layers in which...

  10. The effects of PEG hydrogel crosslinking density on protein diffusion and encapsulated islet survival and function

    OpenAIRE

    Weber, Laney M.; Lopez, Christina G.; Anseth, Kristi S.

    2009-01-01

    The rational design of immunoprotective hydrogel barriers for transplanting insulin-producing cells requires an understanding of protein diffusion within the hydrogel network and how alterations to the network structure affect protein diffusion. Hydrogels of varying crosslinking density were formed via the chain polymerization of dimethacrylated PEG macromers of varying molecular weight, and the diffusion of six model proteins with molecular weights ranging from 5,700 to 67,000 g/mol was obse...

  11. 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...

  12. Hydrogel Microwell Arrays Allow the Assessment of Protease-Associated Enhancement of Cancer Cell Aggregation and Survival

    OpenAIRE

    Dietmar W. Hutmacher; Lutolf, Matthias P.; Daniela Loessner; Judith A. Clements; Stefan Kobel

    2013-01-01

    Current routine cell culture techniques are only poorly suited to capture the physiological complexity of tumor microenvironments, wherein tumor cell function is affected by intricate three-dimensional (3D), integrin-dependent cell-cell and cell-extracellular matrix (ECM) interactions. 3D cell cultures allow the investigation of cancer-associated proteases like kallikreins as they degrade ECM proteins and alter integrin signaling, promoting malignant cell behaviors. Here, we employed a hydrog...

  13. Thermo-responsive hydrogels for intravitreal injection and biomolecule release

    Science.gov (United States)

    Drapala, Pawel

    In this dissertation, we develop an injectable polymer system to enable localized and prolonged release of therapeutic biomolecules for improved treatment of Age-Related Macular Degeneration (AMD). Thermo-responsive hydrogels derived from N-isopropylacrylamide (NIPAAm) and cross-linked with poly(ethylene glycol) (PEG) poly(L-Lactic acid) (PLLA) copolymer were synthesized via free-radical polymerization. These materials were investigated for (a) phase change behavior, (b) in-vitro degradation, (c) capacity for controlled drug delivery, and (d) biocompatibility. The volume-phase transition temperature (VPTT) of the PNIPAAm- co-PEG-b-PLLA hydrogels was adjusted using hydrophilic and hydrophobic moieties so that it is ca. 33°C. These hydrogels did not initially show evidence of degradation at 37°C due to physical cross-links of collapsed PNIPAAm. Only after addition of glutathione chain transfer agents (CTA)s to the precursor did the collapsed hydrogels become fully soluble at 37°C. CTAs significantly affected the release kinetics of biomolecules; addition of 1.0 mg/mL glutathione to 3 mM cross-linker accelerated hydrogel degradation, resulting in 100% release in less than 2 days. This work also explored the effect of PEGylation in order to tether biomolecules to the polymer matrix. It was demonstrated that non-site-specific PEGylation can postpone the burst release of solutes (up to 10 days in hydrogels with 0.5 mg/mL glutathione). Cell viability assays showed that at least two 20-minute buffer extraction steps were needed to remove cytotoxic elements from the hydrogels. Clinically-used therapeutic biomolecules LucentisRTM and AvastinRTM were demonstrated to be both stable and bioactive after release form PNIPAAm-co-PEG-b-PLLA hydrogels. The thermo-responsive hydrogels presented here offer a promising platform for the localized delivery of proteins such as recombinant antibodies.

  14. Estimation of cancerolytic properties of thionine from plants seeds by inclusion of C14-thymidine in tumoral cells

    International Nuclear Information System (INIS)

    Full text: It has been earlier shown that cysteine rich peptides - thionine from seeds of various plants possess expressed fungitoxic activity. It is connected to influence of thionine on cellular membranes of fungi. It was possible to assume that the substances showing cytotoxic activity will be active in relation to tumoral cells. We isolated peptide fractions from seeds bamia (Hibiscus esculentus), kenaf (Hibiscus cannabinus), abutilon (Abutilon theophrasti), euphorbia (Euphorbia virgata), palma Christi (Ricinus communis) and horse sorrel (Rumex confertus) and studied their antineoplastic and fungitoxic activity. Antiproliferative action of peptides to melanoma cells of mice was estimated in cytotoxic test by inclusion of C14-thymidine to DNA. This researches have shown that peptides from seeds of horse sorrel and palma Christi did not change a level of synthesis of DNA while peptides from euphorbia and bamia considerably reduced inclusion of labeled nucleotide to DNA and suppressed growth of tumoral cells on 14 and 39 % accordingly. Parallel tests of these peptides on fungitoxic activity in relation to virulent strains of Verticillium dahliae have shown suppression of conidial growth on 17 and 26 % accordingly. Thus, peptides from seeds of bamia and euphorbia possess the expressed property to suppress growth of tumoral cells and can be used at creation a new cancerolytic preparations for treatment of human cancer. Work is executed under the financial support of fundamental grants F - 4.19 and F-4.1.44

  15. Macroporous hydrogels based on 2-hydroxyethyl methacrylate. Part 4: Growth of rat bone marrow stromal cells in three-dimensional hydrogels with positive and negative surface charges and in polyelectrolyte complexes

    Czech Academy of Sciences Publication Activity Database

    Lesný, Petr; Přádný, Martin; Jendelová, Pavla; Michálek, Jiří; Vacík, Jiří; Syková, Eva

    2006-01-01

    Roč. 17, - (2006), s. 829-833. ISSN 0957-4530 R&D Projects: GA ČR GA203/01/0737; GA MŠk LN00A065; GA ČR(CZ) GA304/03/1189; GA AV ČR IBS4050005; GA MŠk 1M0538 Institutional research plan: CEZ:AV0Z50390512; CEZ:AV0Z40500505 Keywords : Macroporous hydrogels * HEMA Subject RIV: FH - Neurology Impact factor: 1.562, year: 2006

  16. Research on the printability of hydrogels in 3D bioprinting

    Science.gov (United States)

    He, Yong; Yang, FeiFei; Zhao, HaiMing; Gao, Qing; Xia, Bing; Fu, JianZhong

    2016-01-01

    As the biocompatible materials, hydrogels have been widely used in three- dimensional (3D) bioprinting/organ printing to load cell for tissue engineering. It is important to precisely control hydrogels deposition during printing the mimic organ structures. However, the printability of hydrogels about printing parameters is seldom addressed. In this paper, we systemically investigated the printability of hydrogels from printing lines (one dimensional, 1D structures) to printing lattices/films (two dimensional, 2D structures) and printing 3D structures with a special attention to the accurate printing. After a series of experiments, we discovered the relationships between the important factors such as air pressure, feedrate, or even printing distance and the printing quality of the expected structures. Dumbbell shape was observed in the lattice structures printing due to the hydrogel diffuses at the intersection. Collapses and fusion of adjacent layer would result in the error accumulation at Z direction which was an important fact that could cause printing failure. Finally, we successfully demonstrated a 3D printing hydrogel scaffold through harmonize with all the parameters. The cell viability after printing was compared with the casting and the results showed that our bioprinting method almost had no extra damage to the cells. PMID:27436509

  17. Research on the printability of hydrogels in 3D bioprinting.

    Science.gov (United States)

    He, Yong; Yang, FeiFei; Zhao, HaiMing; Gao, Qing; Xia, Bing; Fu, JianZhong

    2016-01-01

    As the biocompatible materials, hydrogels have been widely used in three- dimensional (3D) bioprinting/organ printing to load cell for tissue engineering. It is important to precisely control hydrogels deposition during printing the mimic organ structures. However, the printability of hydrogels about printing parameters is seldom addressed. In this paper, we systemically investigated the printability of hydrogels from printing lines (one dimensional, 1D structures) to printing lattices/films (two dimensional, 2D structures) and printing 3D structures with a special attention to the accurate printing. After a series of experiments, we discovered the relationships between the important factors such as air pressure, feedrate, or even printing distance and the printing quality of the expected structures. Dumbbell shape was observed in the lattice structures printing due to the hydrogel diffuses at the intersection. Collapses and fusion of adjacent layer would result in the error accumulation at Z direction which was an important fact that could cause printing failure. Finally, we successfully demonstrated a 3D printing hydrogel scaffold through harmonize with all the parameters. The cell viability after printing was compared with the casting and the results showed that our bioprinting method almost had no extra damage to the cells. PMID:27436509

  18. Research on the printability of hydrogels in 3D bioprinting

    Science.gov (United States)

    He, Yong; Yang, Feifei; Zhao, Haiming; Gao, Qing; Xia, Bing; Fu, Jianzhong

    2016-07-01

    As the biocompatible materials, hydrogels have been widely used in three- dimensional (3D) bioprinting/organ printing to load cell for tissue engineering. It is important to precisely control hydrogels deposition during printing the mimic organ structures. However, the printability of hydrogels about printing parameters is seldom addressed. In this paper, we systemically investigated the printability of hydrogels from printing lines (one dimensional, 1D structures) to printing lattices/films (two dimensional, 2D structures) and printing 3D structures with a special attention to the accurate printing. After a series of experiments, we discovered the relationships between the important factors such as air pressure, feedrate, or even printing distance and the printing quality of the expected structures. Dumbbell shape was observed in the lattice structures printing due to the hydrogel diffuses at the intersection. Collapses and fusion of adjacent layer would result in the error accumulation at Z direction which was an important fact that could cause printing failure. Finally, we successfully demonstrated a 3D printing hydrogel scaffold through harmonize with all the parameters. The cell viability after printing was compared with the casting and the results showed that our bioprinting method almost had no extra damage to the cells.

  19. Are bone marrow regenerative cells ideal seed cells for the treatment of cerebral ischemia?

    Institute of Scientific and Technical Information of China (English)

    Yi Li; Xuming Hua; Fang Hua; Wenwei Mao; Liang Wan; Shiting Li

    2013-01-01

    Bone marrow cells for the treatment of ischemic brain injury may depend on the secretion of a large number of neurotrophic factors. Bone marrow regenerative cells are capable of increasing the secretion of neurotrophic factors. In this study, after tail vein injection of 5-fluorouracil for 7 days, bone marrow cells and bone marrow regenerative cells were isolated from the tibias and femurs of rats, and then administered intravenously via the tail vein after focal cerebral ischemia. Immunohistological staining and reverse transcription-PCR detection showed that transplanted bone marrow cells and bone marrow regenerative cells could migrate and survive in the ischemic regions, such as the cortical and striatal infarction zone. These cells promote vascular endothelial cell growth factor mRNA expression in the ischemic marginal zone surrounding the ischemic penumbra of the cortical and striatal infarction zone, and have great advantages in promoting the recovery of neurological function, reducing infarct size and promoting angiogenesis. Bone marrow regenerative cells exhibited stronger neuroprotective effects than bone marrow cells. Our experimental findings indicate that bone marrow regenerative cells are preferable over bone marrow cells for cell therapy for neural regeneration after cerebral ischemia. Their neuroprotective effect is largely due to their ability to induce the secretion of factors that promote vascular regeneration, such as vascular endothelial growth factor.

  20. Hydrogels for in vivo-like three-dimensional cellular studies.

    Science.gov (United States)

    DeVolder, Ross; Kong, Hyun-Joon

    2012-01-01

    Extensive efforts have been made to understand the effects of extracellular microenvironments on phenotypic activities for a wide array of stem, progenitor, and precursor cells. Hydrogels have emerged as invaluable platforms for examining the effects of extracellular matrix (ECM) properties on cell activities because of their several advantageous features. Specifically, hydrogels are unique materials that enable cell studies in three-dimensional (3D) environments, similar to in vivo environments. Recently, there have been increasing efforts to assemble cell-encapsulating hydrogels; however, hydrogel design strategies for 3D cell cultures have not been systematically discussed to date. Therefore, this review article summarizes current hydrogel designs for 3D cell culture studies and further discusses current challenges and potential resolutions for enhancing the controllability of hydrogel properties and microstructures. The hydrogels discussed herein include those of natural polymers (e.g., collagen, fibrinogen, alginate, and hyaluronic acids), synthetic polymers [e.g., poly(ethylene glycol) (PEG) and its derivatives], and mixtures of natural and synthetic polymers. We envision that hydrogels that enable 3D studies will greatly assist in the understanding of emergent cell behaviors, and ultimately become important biomedical tools for enhancing the quality of in vitro drug screening and clinical treatments. PMID:22615143