101
|
Petruczok CD, Yang R, Gleason KK. Controllable Cross-Linking of Vapor-Deposited Polymer Thin Films and Impact on Material Properties. Macromolecules 2013. [DOI: 10.1021/ma302566r] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Affiliation(s)
- Christy D. Petruczok
- Department
of Chemical Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge,
Massachusetts 02139, United States
| | - Rong Yang
- Department
of Chemical Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge,
Massachusetts 02139, United States
| | - Karen K. Gleason
- Department
of Chemical Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge,
Massachusetts 02139, United States
| |
Collapse
|
102
|
Popa EG, Caridade SG, Mano JF, Reis RL, Gomes ME. Chondrogenic potential of injectable κ-carrageenan hydrogel with encapsulated adipose stem cells for cartilage tissue-engineering applications. J Tissue Eng Regen Med 2013; 9:550-63. [PMID: 23303734 DOI: 10.1002/term.1683] [Citation(s) in RCA: 89] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2012] [Accepted: 11/14/2012] [Indexed: 11/11/2022]
Abstract
Due to the limited self-repair capacity of cartilage, regenerative medicine therapies for the treatment of cartilage defects must use a significant amount of cells, preferably applied using a hydrogel system that can promise their delivery and functionality at the specific site. This paper discusses the potential use of κ-carrageenan hydrogels for the delivery of stem cells obtained from adipose tissue in the treatment of cartilage tissue defects. The developed hydrogels were produced by an ionotropic gelation method and human adipose stem cells (hASCs) were encapsulated in 1.5% w/v κ-carrageenan solution at a cell density of 5 × 10(6) cells/ml. The results from the analysis of the cell-encapsulating hydrogels, cultured for up to 21 days, indicated that κ-carrageenan hydrogels support the viability, proliferation and chondrogenic differentiation of hASCs. Additionally, the mechanical analysis demonstrated an increase in stiffness and viscoelastic properties of κ-carrageenan gels with their encapsulated cells with increasing time in culture with chondrogenic medium. These results allowed the conclusion that κ-carrageenan exhibits properties that enable the in vitro functionality of encapsulated hASCs and thus may provide the basis for new successful approaches for the treatment of cartilage defects.
Collapse
Affiliation(s)
- Elena G Popa
- 3Bs Research Group - Biomaterials, Biodegradables and Biomimetics, University of Minho, Guimarães, Portugal; ICVS/3Bs - PT Government Associate Laboratory, Braga/Guimarães, Portugal
| | | | | | | | | |
Collapse
|
103
|
Baldwin AD, Kiick KL. Reversible maleimide-thiol adducts yield glutathione-sensitive poly(ethylene glycol)-heparin hydrogels. Polym Chem 2013; 4:133-143. [PMID: 23766781 DOI: 10.1039/c2py20576a] [Citation(s) in RCA: 123] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
We have recently reported that retro Michael-type addition reactions can be employed for producing labile chemical linkages with tunable sensitivity to physiologically relevant reducing potentials. We reasoned that such strategies would also be useful in the design of glutathione-sensitive hydrogels for a variety of targeted delivery and tissue engineering applications. In this report, we describe hydrogels in which maleimide-functionalized low molecular weight heparin (LMWH) is crosslinked with various thiol-functionalized poly(ethylene glycol) (PEG) multi-arm star polymers. Judicious selection of the chemical identity of the thiol permits tuning of degradation via previously unstudied, but versatile chemical methods. Thiol pKa and hydrophobicity affected both the gelation and degradation of these hydrogels. Maleimide-thiol crosslinking reactions and retro Michael-type addition reactions were verified with 1H NMR during the crosslinking and degradation of hydrogels. PEGs esterified with phenylthiol derivatives, specifically 4-mercaptophenylpropionic acid or 2,2-dimethyl-3-(4-mercaptophenyl)propionic acid, induced sensitivity to glutathione as shown by a decrease in hydrogel degradation time of 4-fold and 5-fold respectively, measured via spectrophotometric quantification of LMWH. The degradation proceeded through the retro Michael-type addition of the succinimide thioether linkage, with apparent pseudo-first order reaction constants derived from oscillatory rheology experiments of 0.039 ± 0.006 h-1 and 0.031 ± 0.003 h-1. The pseudo-first order retro reaction constants were approximately an order of magnitude slower than the degradation rate constants for hydrogels crosslinked via disulfide linkages, indicating the potential use of these Michael-type addition products for reduction-mediated release and/or degradation, with increased blood stability and prolonged drug delivery timescales compared to disulfide moieties.
Collapse
Affiliation(s)
- Aaron D Baldwin
- Department of Materials Science and Engineering, University of Delaware, 201 DuPont Hall, Newark, DE 19716, USA
| | | |
Collapse
|
104
|
Welzel PB, Grimmer M, Renneberg C, Naujox L, Zschoche S, Freudenberg U, Werner C. Macroporous StarPEG-Heparin Cryogels. Biomacromolecules 2012; 13:2349-58. [DOI: 10.1021/bm300605s] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Affiliation(s)
- Petra B. Welzel
- Leibniz
Institute of Polymer Research Dresden
(IPF), Max Bergmann Center of Biomaterials Dresden (MBC) and Technische Universität Dresden (TUD), Center for Regenerative Therapies Dresden (CRTD), Hohe Str.
6, 01069 Dresden, Germany
| | - Milauscha Grimmer
- Leibniz
Institute of Polymer Research Dresden
(IPF), Max Bergmann Center of Biomaterials Dresden (MBC) and Technische Universität Dresden (TUD), Center for Regenerative Therapies Dresden (CRTD), Hohe Str.
6, 01069 Dresden, Germany
| | - Claudia Renneberg
- Leibniz
Institute of Polymer Research Dresden
(IPF), Max Bergmann Center of Biomaterials Dresden (MBC) and Technische Universität Dresden (TUD), Center for Regenerative Therapies Dresden (CRTD), Hohe Str.
6, 01069 Dresden, Germany
| | - Lisa Naujox
- Leibniz
Institute of Polymer Research Dresden
(IPF), Max Bergmann Center of Biomaterials Dresden (MBC) and Technische Universität Dresden (TUD), Center for Regenerative Therapies Dresden (CRTD), Hohe Str.
6, 01069 Dresden, Germany
| | - Stefan Zschoche
- Leibniz
Institute of Polymer Research Dresden
(IPF), Max Bergmann Center of Biomaterials Dresden (MBC) and Technische Universität Dresden (TUD), Center for Regenerative Therapies Dresden (CRTD), Hohe Str.
6, 01069 Dresden, Germany
| | - Uwe Freudenberg
- Leibniz
Institute of Polymer Research Dresden
(IPF), Max Bergmann Center of Biomaterials Dresden (MBC) and Technische Universität Dresden (TUD), Center for Regenerative Therapies Dresden (CRTD), Hohe Str.
6, 01069 Dresden, Germany
| | - Carsten Werner
- Leibniz
Institute of Polymer Research Dresden
(IPF), Max Bergmann Center of Biomaterials Dresden (MBC) and Technische Universität Dresden (TUD), Center for Regenerative Therapies Dresden (CRTD), Hohe Str.
6, 01069 Dresden, Germany
| |
Collapse
|
105
|
Gaudet ID, Shreiber DI. Characterization of methacrylated type-I collagen as a dynamic, photoactive hydrogel. Biointerphases 2012; 7:25. [PMID: 22589068 DOI: 10.1007/s13758-012-0025-y] [Citation(s) in RCA: 74] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2011] [Accepted: 02/23/2012] [Indexed: 12/21/2022] Open
Abstract
Type-I collagen is an attractive scaffold material for tissue engineering due to its ability to self-assemble into a fibrillar hydrogel, its innate support of tissue cells through bioactive adhesion sites, and its biodegradability. However, a lack of control of material properties has hampered its utility as a scaffold. We have modified collagen via the addition of methacrylate groups to create collagen methacrylamide (CMA) using a synthesis reaction that allows retention of fundamental characteristics of native collagen, including spontaneous fibrillar self-assembly and enzymatic biodegradability. This method allows for a rapid, five-fold increase in storage modulus upon irradiation with 365 nm light. Fibrillar diameter of CMA was not significantly different from native collagen. Collagenolytic degradability of uncrosslinked CMA was minimally reduced, while photocrosslinked CMA was significantly more resistant to degradation. Live/Dead staining demonstrated that a large majority (71%) of encapsulated mesenchymal stem cells remained viable 24 h after photocrosslinking, which further increased to 81% after 72 h. This material represents a novel platform for creating mechanically heterogeneous environments.
Collapse
Affiliation(s)
- Ian D Gaudet
- Department of Biomedical Engineering, Rutgers, The State University of New Jersey, 599 Taylor Road, Piscataway, NJ 08854, USA
| | | |
Collapse
|
106
|
Molinos M, Carvalho V, Silva DM, Gama FM. Development of a Hybrid Dextrin Hydrogel Encapsulating Dextrin Nanogel As Protein Delivery System. Biomacromolecules 2012; 13:517-27. [DOI: 10.1021/bm2015834] [Citation(s) in RCA: 67] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Affiliation(s)
- Maria Molinos
- IBB, Institute for Biotechnology and Bioengineering,
Centre of Biological Engineering, Universidade do Minho, Campus de Gualtar, 4710-057, Braga, Portugal
| | - Vera Carvalho
- IBB, Institute for Biotechnology and Bioengineering,
Centre of Biological Engineering, Universidade do Minho, Campus de Gualtar, 4710-057, Braga, Portugal
| | - Dina M. Silva
- IBB, Institute for Biotechnology and Bioengineering,
Centre of Biological Engineering, Universidade do Minho, Campus de Gualtar, 4710-057, Braga, Portugal
| | - Francisco M. Gama
- IBB, Institute for Biotechnology and Bioengineering,
Centre of Biological Engineering, Universidade do Minho, Campus de Gualtar, 4710-057, Braga, Portugal
| |
Collapse
|
107
|
Xu J, Filion TM, Prifti F, Song J. Cytocompatible poly(ethylene glycol)-co-polycarbonate hydrogels cross-linked by copper-free, strain-promoted click chemistry. Chem Asian J 2011; 6:2730-7. [PMID: 21954076 PMCID: PMC3689886 DOI: 10.1002/asia.201100411] [Citation(s) in RCA: 84] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2011] [Indexed: 01/12/2023]
Abstract
Strategies to encapsulate cells in cytocompatible three-dimensional hydrogels with tunable mechanical properties and degradability without harmful gelling conditions are highly desired for regenerative medicine applications. Here we reported a method for preparing poly(ethylene glycol)-co-polycarbonate hydrogels through copper-free, strain-promoted azide-alkyne cycloaddition (SPAAC) click chemistry. Hydrogels with varying mechanical properties were formed by "clicking" azido-functionalized poly(ethylene glycol)-co-polycarbonate macromers with dibenzocyclooctyne-functionalized poly(ethylene glycol) under physiological conditions within minutes. Bone marrow stromal cells encapsulated in these gels exhibited higher cellular viability than those encapsulated in photo-cross-linked poly(ethylene glycol) dimethacrylate. The precise control over the macromer compositions, cytocompatible SPAAC cross-linking, and the degradability of the polycarbonate segments make these hydrogels promising candidates for scaffold and stem cell assisted tissue repair and regeneration.
Collapse
Affiliation(s)
| | | | | | - Jie Song
- Dr. J. Xu, T. M. Filion, F. Prifti and Prof. J. Song, Department of Orthopedics & Physical Rehabilitation, Department of Cell Biology, University of Massachusetts Medical School, 55 Lake Avenue North, Worcester, MA 01655 USA, Fax: (+1) 508-334-2770
| |
Collapse
|
108
|
King SM, Quartuccio S, Hilliard TS, Inoue K, Burdette JE. Alginate hydrogels for three-dimensional organ culture of ovaries and oviducts. J Vis Exp 2011:2804. [PMID: 21712801 DOI: 10.3791/2804] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
Ovarian cancer is the fifth leading cause of cancer deaths in women and has a 63% mortality rate in the United States(1). The cell type of origin for ovarian cancers is still in question and might be either the ovarian surface epithelium (OSE) or the distal epithelium of the fallopian tube fimbriae(2,3). Culturing the normal cells as a primary culture in vitro will enable scientists to model specific changes that might lead to ovarian cancer in the distinct epithelium, thereby definitively determining the cell type of origin. This will allow development of more accurate biomarkers, animal models with tissue-specific gene changes, and better prevention strategies targeted to this disease. Maintaining normal cells in alginate hydrogels promotes short term in vitro culture of cells in their three-dimensional context and permits introduction of plasmid DNA, siRNA, and small molecules. By culturing organs in pieces that are derived from strategic cuts using a scalpel, several cultures from a single organ can be generated, increasing the number of experiments from a single animal. These cuts model aspects of ovulation leading to proliferation of the OSE, which is associated with ovarian cancer formation. Cell types such as the OSE that do not grow well on plastic surfaces can be cultured using this method and facilitate investigation into normal cellular processes or the earliest events in cancer formation(4). Alginate hydrogels can be used to support the growth of many types of tissues(5). Alginate is a linear polysaccharide composed of repeating units of β-D-mannuronic acid and α-L-guluronic acid that can be crosslinked with calcium ions, resulting in a gentle gelling action that does not damage tissues(6,7). Like other three-dimensional cell culture matrices such as Matrigel, alginate provides mechanical support for tissues; however, proteins are not reactive with the alginate matrix, and therefore alginate functions as a synthetic extracellular matrix that does not initiate cell signaling(5). The alginate hydrogel floats in standard cell culture medium and supports the architecture of the tissue growth in vitro. A method is presented for the preparation, separation, and embedding of ovarian and oviductal organ pieces into alginate hydrogels, which can be maintained in culture for up to two weeks. The enzymatic release of cells for analysis of proteins and RNA samples from the organ culture is also described. Finally, the growth of primary cell types is possible without genetic immortalization from mice and permits investigators to use knockout and transgenic mice.
Collapse
Affiliation(s)
- Shelby M King
- Medicinal Chemistry and Pharmacognosy, University of Illinois at Chicago, USA
| | | | | | | | | |
Collapse
|
109
|
McKee CT, Last JA, Russell P, Murphy CJ. Indentation versus tensile measurements of Young's modulus for soft biological tissues. TISSUE ENGINEERING. PART B, REVIEWS 2011; 17:155-64. [PMID: 21303220 PMCID: PMC3099446 DOI: 10.1089/ten.teb.2010.0520] [Citation(s) in RCA: 393] [Impact Index Per Article: 30.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/01/2010] [Accepted: 02/07/2011] [Indexed: 12/21/2022]
Abstract
In this review, we compare the reported values of Young's modulus (YM) obtained from indentation and tensile deformations of soft biological tissues. When the method of deformation is ignored, YM values for any given tissue typically span several orders of magnitude. If the method of deformation is considered, then a consistent and less ambiguous result emerges. On average, YM values for soft tissues are consistently lower when obtained by indentation deformations. We discuss the implications and potential impact of this finding.
Collapse
Affiliation(s)
- Clayton T. McKee
- Department of Surgical and Radiological Science, School of Veterinary Medicine, University of California Davis, Davis, California
| | - Julie A. Last
- Department of Chemical and Biological Engineering, University of Wisconsin–Madison, Madison, Wisconsin
| | - Paul Russell
- Department of Surgical and Radiological Science, School of Veterinary Medicine, University of California Davis, Davis, California
| | - Christopher J. Murphy
- Department of Surgical and Radiological Science, School of Veterinary Medicine, University of California Davis, Davis, California
- Department of Ophthalmology and Vision Science, School of Medicine, University of California Davis, Davis, California
| |
Collapse
|
110
|
Duan P, Qin L, Zhu X, Liu M. Hierarchical Self‐Assembly of Amphiphilic Peptide Dendrons: Evolution of Diverse Chiral Nanostructures Through Hydrogel Formation Over a Wide pH Range. Chemistry 2011; 17:6389-95. [DOI: 10.1002/chem.201003049] [Citation(s) in RCA: 98] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2010] [Indexed: 11/09/2022]
Affiliation(s)
- Pengfei Duan
- Beijing National Laboratory for Molecular Science, CAS Key Laboratory of Colloid Interface and Chemical Thermodynamics, Institute of Chemistry, Chinese Academy of Sciences, Beijing, 100190 (P.R. China), Fax: (+86) ‐10‐62569564
| | - Long Qin
- Beijing National Laboratory for Molecular Science, CAS Key Laboratory of Colloid Interface and Chemical Thermodynamics, Institute of Chemistry, Chinese Academy of Sciences, Beijing, 100190 (P.R. China), Fax: (+86) ‐10‐62569564
| | - Xuefeng Zhu
- Beijing National Laboratory for Molecular Science, CAS Key Laboratory of Colloid Interface and Chemical Thermodynamics, Institute of Chemistry, Chinese Academy of Sciences, Beijing, 100190 (P.R. China), Fax: (+86) ‐10‐62569564
| | - Minghua Liu
- Beijing National Laboratory for Molecular Science, CAS Key Laboratory of Colloid Interface and Chemical Thermodynamics, Institute of Chemistry, Chinese Academy of Sciences, Beijing, 100190 (P.R. China), Fax: (+86) ‐10‐62569564
| |
Collapse
|
111
|
Modulating Biofunctional starPEG Heparin Hydrogels by Varying Size and Ratio of the Constituents. Polymers (Basel) 2011. [DOI: 10.3390/polym3010602] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
|
112
|
Bidarra SJ, Barrias CC, Barbosa MA, Soares R, Granja PL. Immobilization of human mesenchymal stem cells within RGD-grafted alginate microspheres and assessment of their angiogenic potential. Biomacromolecules 2010; 11:1956-64. [PMID: 20690708 DOI: 10.1021/bm100264a] [Citation(s) in RCA: 119] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
In this work, human mesenchymal stem cells (hMSC) immobilized in RGD-coupled alginate microspheres, with a binary composition of high and low molecular weight alginate, were investigated. Cells immobilized within RGD-alginate microspheres (during 21 days) showed metabolic activity, with an overall viability higher than 90%, short cell extensions, and, when induced, they were able to differentiate into the osteogenic lineage. In osteogenic conditions (comparing to basal conditions), immobilized cells presented alkaline phosphatase (ALP) activity and an upregulation of ALP, collagen type I, and Runx 2 expression. Moreover, mineralization was also detected in immobilized cells under osteogenic stimulus. In addition, it was demonstrated for the first time that MSCs immobilized in this 3D matrix were able to enhance the ability of neighboring endothelial cells to form tubelike structures. Overall, these findings represent a step forward in the development of injectable stem cell carriers for bone tissue engineering.
Collapse
Affiliation(s)
- Sílvia J Bidarra
- INEB-Instituto de Engenharia Biomedica, Rua do Campo Alegre No. 823, 4150-180 Porto, Portugal
| | | | | | | | | |
Collapse
|
113
|
Lanasa SM, Hoffecker IT, Bryant SJ. Presence of pores and hydrogel composition influence tensile properties of scaffolds fabricated from well-defined sphere templates. J Biomed Mater Res B Appl Biomater 2010; 96:294-302. [PMID: 21210509 DOI: 10.1002/jbm.b.31765] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2010] [Revised: 06/30/2010] [Accepted: 07/07/2010] [Indexed: 01/16/2023]
Abstract
Sphere templating is an attractive method to produce porous polymeric scaffolds with well-defined and uniform pore structures for applications in tissue engineering. While high porosity is desired to facilitate cell seeding and enhance nutrient transport, the incorporation of pores will impact gross mechanical properties of tissue scaffolds and will likely be dependent on pore size. The goals of this study were to evaluate the effect of pores, pore diameter, and polymer composition on gross mechanical properties of hydrogels prepared from crosslinked poly(ethylene glycol) (PEG) and poly(2-hydroxyethyl methacrylate) (pHEMA). Sphere templates were fabricated from uncrosslinked poly(methyl methacrylate) spheres sieved between 53-63 and 150-180 μm. Incorporating pores into hydrogels significantly decreased the quasi-static modulus and ultimate tensile stress, but increased the ultimate tensile strain. For pHEMA, decreases in gel crosslinking density and increases in pore diameters followed similar trends. Interestingly, the mechanical properties of porous PEG hydrogels were less sensitive to changes in pore diameter for a given polymer composition. Additionally, pore diameter was shown to affect skeletal myoblast adhesion whereby many cells cultured in porous hydrogels with smaller pores were seen spanning across multiple pores, but lined the inside of larger pores. In summary, incorporation of pores and changes in pore diameter significantly affect the gross mechanical properties, but in a manner that is dependent on gel chemistry, structure, and composition. Together, these findings will help to design better hydrogel scaffolds for applications where gross mechanical properties and porosity are critical.
Collapse
Affiliation(s)
- Stephanie M Lanasa
- Department of Chemical and Biological Engineering, The University of Colorado at Boulder, Boulder, Colorado 80309, USA
| | | | | |
Collapse
|
114
|
Panda JJ, Dua R, Mishra A, Mittra B, Chauhan VS. 3D cell growth and proliferation on a RGD functionalized nanofibrillar hydrogel based on a conformationally restricted residue containing dipeptide. ACS APPLIED MATERIALS & INTERFACES 2010; 2:2839-2848. [PMID: 20886861 DOI: 10.1021/am1005173] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Three-dimensional (3D) hydrogels incorporating a compendium of bioactive molecules can allow efficient proliferation and differentiation of cells and can thus act as successful tissue engineering scaffolds. Self-assembled peptide-based hydrogels can be worthy candidates for such applications as peptides are biocompatible, biodegradable and can be easily functionalized with desired moieties. Here, we report 3D growth and proliferation of mammalian cells (HeLa and L929) on a dipeptide hydrogel chemically functionalized with a pentapeptide containing Arg-Gly-Asp (RGD) motif. The method of functionalization is simple, direct and can be adapted to other functional moieties as well. The functionalized gel was noncytotoxic, exhibited enhanced cell growth promoting properties, and promoted 3D growth and proliferation of cells for almost 2 weeks, with simultaneous preservation of their metabolic activities. The presence of effective cell growth supporting properties in a simple and easy to functionalize dipeptide hydrogel is unique and makes it a promising candidate for tissue engineering and cell biological applications.
Collapse
Affiliation(s)
- Jiban J Panda
- International Centre for Genetic Engineering and Biotechnology, New Delhi, India
| | | | | | | | | |
Collapse
|
115
|
Dave N, Chan MY, Huang PJJ, Smith BD, Liu J. Regenerable DNA-Functionalized Hydrogels for Ultrasensitive, Instrument-Free Mercury(II) Detection and Removal in Water. J Am Chem Soc 2010; 132:12668-73. [PMID: 20726570 DOI: 10.1021/ja106098j] [Citation(s) in RCA: 335] [Impact Index Per Article: 23.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- Neeshma Dave
- Department of Chemistry, Waterloo Institute for Nanotechnology, University of Waterloo, 200 University Avenue West, Waterloo, Ontario N2L 3G1, Canada
| | - Michelle Y. Chan
- Department of Chemistry, Waterloo Institute for Nanotechnology, University of Waterloo, 200 University Avenue West, Waterloo, Ontario N2L 3G1, Canada
| | - Po-Jung Jimmy Huang
- Department of Chemistry, Waterloo Institute for Nanotechnology, University of Waterloo, 200 University Avenue West, Waterloo, Ontario N2L 3G1, Canada
| | - Brendan D. Smith
- Department of Chemistry, Waterloo Institute for Nanotechnology, University of Waterloo, 200 University Avenue West, Waterloo, Ontario N2L 3G1, Canada
| | - Juewen Liu
- Department of Chemistry, Waterloo Institute for Nanotechnology, University of Waterloo, 200 University Avenue West, Waterloo, Ontario N2L 3G1, Canada
| |
Collapse
|
116
|
Fu J, Cai K, Johnston SA, Woodbury NW. Exploring peptide space for enzyme modulators. J Am Chem Soc 2010; 132:6419-24. [PMID: 20408521 DOI: 10.1021/ja100403a] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
A method is presented for screening high-density arrays to discover peptides that bind and modulate enzyme activity. A polyvinyl alcohol solution was applied to array surfaces to limit the diffusion of product molecules released from enzymatic reactions, allowing the simultaneous measurement of enzyme activity and binding at each peptide spot. For proof of concept, it was possible to identify peptides that bound to horseradish peroxidase, alkaline phosphatase, and beta-galactosidase and substantially altered enzyme activity by comparing the binding level of peptide to enzyme and bound enzyme activity. This basic technique may be generally applicable to find peptides or other small molecules that modify enzyme activity.
Collapse
Affiliation(s)
- Jinglin Fu
- Center for Single Molecule Biophysics, Arizona State University, Tempe, Arizona 85287, USA
| | | | | | | |
Collapse
|
117
|
Yan T, Sun R, Li C, Tan B, Mao X, Ao N. Immobilization of type-I collagen and basic fibroblast growth factor (bFGF) onto poly (HEMA-co-MMA) hydrogel surface and its cytotoxicity study. JOURNAL OF MATERIALS SCIENCE. MATERIALS IN MEDICINE 2010; 21:2425-2433. [PMID: 20502949 DOI: 10.1007/s10856-010-4094-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/25/2010] [Accepted: 05/05/2010] [Indexed: 05/28/2023]
Abstract
Type-I collagen and bFGF were immobilized onto the surface of poly (HEMA-co-MMA) hydrogel by grafting and coating methods to improve its cytotoxicity. The multi-layered structure of the biocompatible layer was confirmed by FTIR, AFM and static water contact angles. The layers were stable in body-like environment (pH 7.4). Human skin fibroblast cells (HSFC) were seeded onto Col/bFGF-poly (HEMA-co-MMA), Col-poly (HEMA-co-MMA) and poly (HEMA-co-MMA) films for 1, 3 and 5 day. MTT assay was performed to evaluate the extraction toxicity of the materials. Results showed that the cell attachment, proliferation and differentiation on Col/bFGF-poly (HEMA-co-MMA) film were higher than those of the control group, which indicated the improvement of cell-material interaction. The extraction toxicity of the modified materials was also lower than that of the unmodified group. The protein and bFGF immobilized poly (HEMA-co-MMA) hydrogel might hold great promise to be a biocompatible material.
Collapse
Affiliation(s)
- Tuo Yan
- Department of Biomedical Engineering, Jinan University, Guangzhou, China.
| | | | | | | | | | | |
Collapse
|
118
|
Multiphysics modeling of responsive characteristics of ionic-strength-sensitive hydrogel. Biomed Microdevices 2010; 12:419-34. [PMID: 20195766 DOI: 10.1007/s10544-010-9399-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
A multiphysics model is developed in this paper for simulation of the volume transition mechanism of the smart hydrogel in response to the changes in the ionic strength of bathing solution as an important measure of the ionic concentration of that solution, which is termed the multi-effect-coupling ionic-strength-stimulus (MECis) model. In the present works, the ionic strength is treated as a main stimulus and incorporated into both the ionic convection-diffusion system in the Nernst-Planck flux and the fixed charge density equation characterized by Langmuir isotherm theory. Due to the diffusion and convection, the osmotic pressure is produced by the difference in the ionic concentration between the interior hydrogel and exterior solution, which drives the swelling of the smart hydrogel. The deformation of the ionic-strength-sensitive hydrogel is described by the momentum conservation law, in which the osmotic pressure is a main driving source. Apart from osmotic pressure, however, the repulsive force between the fixed charges is also considered in the mechanical equilibrium equation as another driving source for the swelling of the hydrogel. The simulation is conducted for one-dimensional steady-state problem, and then compared with the experimental data and other theories from open literature. The comparisons demonstrate that the MECis model can simulate well the swelling behavior of the ionic-strength-sensitive hydrogel qualitatively and quantitatively. Probably it is able to predict the responsive characteristics of the bathing solution including the distribution of diffusive ionic concentrations and electrical potential.
Collapse
|
119
|
Wang B, Liu P, Tang R. Cellular shellization: Surface engineering gives cells an exterior. Bioessays 2010; 32:698-708. [DOI: 10.1002/bies.200900120] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
|
120
|
Stella JA, D'Amore A, Wagner WR, Sacks MS. On the biomechanical function of scaffolds for engineering load-bearing soft tissues. Acta Biomater 2010; 6:2365-81. [PMID: 20060509 DOI: 10.1016/j.actbio.2010.01.001] [Citation(s) in RCA: 84] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2009] [Revised: 12/18/2009] [Accepted: 01/04/2010] [Indexed: 11/16/2022]
Abstract
Replacement or regeneration of load-bearing soft tissues has long been the impetus for the development of bioactive materials. While maturing, current efforts continue to be confounded by our lack of understanding of the intricate multi-scale hierarchical arrangements and interactions typically found in native tissues. The current state of the art in biomaterial processing enables a degree of controllable microstructure that can be used for the development of model systems to deduce fundamental biological implications of matrix morphologies on cell function. Furthermore, the development of computational frameworks which allow for the simulation of experimentally derived observations represents a positive departure from what has mostly been an empirically driven field, enabling a deeper understanding of the highly complex biological mechanisms we wish to ultimately emulate. Ongoing research is actively pursuing new materials and processing methods to control material structure down to the micro-scale to sustain or improve cell viability, guide tissue growth, and provide mechanical integrity, all while exhibiting the capacity to degrade in a controlled manner. The purpose of this review is not to focus solely on material processing but to assess the ability of these techniques to produce mechanically sound tissue surrogates, highlight the unique structural characteristics produced in these materials, and discuss how this translates to distinct macroscopic biomechanical behaviors.
Collapse
Affiliation(s)
- John A Stella
- Department of Bioengineering, Swanson School of Engineering, University of Pittsburgh, Pittsburgh, PA 15219, USA
| | | | | | | |
Collapse
|
121
|
Forster REJ, Thürmer F, Wallrapp C, Lloyd AW, Macfarlane W, Phillips GJ, Boutrand JP, Lewis AL. Characterisation of physico-mechanical properties and degradation potential of calcium alginate beads for use in embolisation. JOURNAL OF MATERIALS SCIENCE. MATERIALS IN MEDICINE 2010; 21:2243-2251. [PMID: 20411308 PMCID: PMC2898106 DOI: 10.1007/s10856-010-4080-y] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/01/2010] [Accepted: 04/01/2010] [Indexed: 05/29/2023]
Abstract
High molecular weight alginate beads with 59% mannuronic acid content or 68% guluronic acid were prepared using a droplet generator and crosslinked in calcium chloride. The alginate beads were compared to current embolisation microspheres for compressibility and monitored over 12 weeks for size and weight change at 37 degrees C in low volumes of ringers solutions. A sheep uterine model was used to analyse bead degradation and inflammatory response over 12 weeks. Both the in vitro and in vivo data show good delivery, with a compressibility similar to current embolic beads. In vitro, swelling was noted almost immediately and after 12 weeks the first signs of degradation were noted. No difference was noted in vivo. This study has shown that high molecular weight alginate gel beads were well tolerated by the body, but beads associated with induced thrombi were susceptible to inflammatory cell infiltration. The beads were shown to be easy to handle and were still observable after 3 months in vivo. The beads were robust enough to be delivered through a 2.7 Fr microcatheter. This study has demonstrated that high molecular weight, high purity alginate bead can be considered as semi-permanent embolisation beads, with the potential to bioresorb over time.
Collapse
Affiliation(s)
- Richard E. J. Forster
- Biocompatibles UK Ltd., Farnham Business Park, Weydon Lane, Farnham, Surrey GU9 8QL UK
- Biomedical Materials Research Group, School of Pharmacy and Biomolecular Sciences, University of Brighton, Mouslecoomb, Brighton, E.Sussex BN2 4GJ UK
| | - Frank Thürmer
- CellMed AG, Industriestraße 19, 63755 Alzenau, Germany
| | | | - Andrew W. Lloyd
- Biomedical Materials Research Group, School of Pharmacy and Biomolecular Sciences, University of Brighton, Mouslecoomb, Brighton, E.Sussex BN2 4GJ UK
| | - Wendy Macfarlane
- Biomedical Materials Research Group, School of Pharmacy and Biomolecular Sciences, University of Brighton, Mouslecoomb, Brighton, E.Sussex BN2 4GJ UK
| | - Gary J. Phillips
- Biomedical Materials Research Group, School of Pharmacy and Biomolecular Sciences, University of Brighton, Mouslecoomb, Brighton, E.Sussex BN2 4GJ UK
| | - Jean-Pierre Boutrand
- Biomatech S.A., Zone Industrielle de I’Islon, 115 Rue Pasteur, 38670 Chasse-sur-Rhone, France
| | - Andrew L. Lewis
- Biocompatibles UK Ltd., Farnham Business Park, Weydon Lane, Farnham, Surrey GU9 8QL UK
| |
Collapse
|
122
|
Lai F, Li H. Transient modeling for kinetic swelling/deswelling of the ionic-strength-sensitive hydrogel. THE EUROPEAN PHYSICAL JOURNAL. E, SOFT MATTER 2010; 31:269-274. [PMID: 20229014 DOI: 10.1140/epje/i2010-10572-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/01/2009] [Revised: 01/25/2010] [Accepted: 01/26/2010] [Indexed: 05/28/2023]
Abstract
The multi-effect-coupling ionic-strength-stimulus (MECis) model is presented for transient simulation of the kinetic deformation behavior of the ionic-strength-sensitive hydrogel, based on the laws of conservation of mass and momentum, where the chemical, electrical and mechanical effects are considered on the kinetics of the hydrogel. The simulated kinetic swelling/shrinking characteristics by the MECis model are compared with the experiments. It is concluded that the model is able to predict well the responsive variation of the ionic-strength-sensitive hydrogel with time.
Collapse
Affiliation(s)
- Fukun Lai
- School of Mechanical and Aerospace Engineering, Nanyang Technological University, 50 Nanyang Avenue, 639798, Singapore, Singapore
| | | |
Collapse
|
123
|
Leick S, Henning S, Degen P, Suter D, Rehage H. Deformation of liquid-filled calcium alginate capsules in a spinning drop apparatus. Phys Chem Chem Phys 2010; 12:2950-8. [DOI: 10.1039/b921116k] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
124
|
Scharnagl N, Lee S, Hiebl B, Sisson A, Lendlein A. Design principles for polymers as substratum for adherent cells. ACTA ACUST UNITED AC 2010. [DOI: 10.1039/c0jm00997k] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
|
125
|
Rago AP, Chai PR, Morgan JR. Encapsulated arrays of self-assembled microtissues: an alternative to spherical microcapsules. Tissue Eng Part A 2009; 15:387-95. [PMID: 19193131 DOI: 10.1089/ten.tea.2008.0107] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Micro-encapsulation and immuno-isolation of allogenic and xenogenic tissues and cells is a promising method for the treatment of a variety of metabolic disorders. Many years have been spent optimizing spherical microcapsules, yet micro-encapsulation has not achieved its full clinical potential. As an alternative to spherical microcapsules, this study presents an alginate-encapsulated array of self-assembled three-dimensional (3D) microtissues. Monodispersed HepG2 cells were seeded onto a micro-molded agarose gel. Cells settled to the bottom of the mold recesses and self-assembled 3D microtissues (n = 822) within 24 h. This array of densely packed microtissues was encapsulated in situ using alginate. When separated from the agarose micro-mold, the encapsulated array had HepG2 microtissues in close proximity to its surface. This surface could be further modified by a simple dipping process. Microtissue size, viability, and albumin secretion were all controllable by the number of cells seeded onto the original agarose micro-mold, and microtissue shape and spacing were controllable by the design of the micro-mold. This approach to encapsulation and the use of self-assembled/self-packing 3D microtissues offers new design possibilities that may help to address certain limitations of conventional microcapsules.
Collapse
Affiliation(s)
- Adam P Rago
- Department of Molecular Pharmacology, Physiology, and Biotechnology, Center for Biomedical Engineering, Brown University, Providence, Rhode Island 02912, USA
| | | | | |
Collapse
|
126
|
Buscemi S, Lazzara G, Milioto S, Palumbo Piccionello A. Extended investigation of the aqueous self-assembling behavior of a newly designed fluorinated surfactant. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2009; 25:13368-13375. [PMID: 19689146 DOI: 10.1021/la9019487] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
The physicochemical behavior of the newly synthesized fluorinated 5-hydroxyamino-3-perfluoroheptyl-1,2,4-oxadiazin-6-one (PFHO) surfactant was investigated. Thermal analysis showed that the pure surfactant is thermally stable under an inert atmosphere to 135 degrees C, which is several degrees higher than the melting point (99 degrees C). PFHO is rather active at the water/air interface where it assumes a standing up configuration. It exhibits an enhanced self-assembling behavior; accordingly, the critical micellar concentrations at some temperatures are 2 orders of magnitude lower than those of a similar surfactant having the same phobicity, such as sodium perfluorooctanoate. Even in the dilute domains, PFHO forms large micelles, detected by dynamic light scattering studies, that are precursors of the gel occurring at rather low composition (only 2.0% w/w at 25 degrees C). Optical microscopy evidenced cylindrical aggregates in gel systems whereas differential scanning calorimetry and viscosity showed that the gels are stable over a wide temperature range to ca. 70 degrees C where they undergo a reversible gel --> fluid transition. Finally, percolation theory combined with data provided by the experimental studies enabled us to predict the PFHO gelation process correctly, in very good agreement with the experimental findings.
Collapse
Affiliation(s)
- S Buscemi
- Dipartimento di Chimica Organica E. Paternò, Università degli Studi di Palermo, Viale delle Scienze, Parco D'Orleans II, 90128 Palermo, Italy
| | | | | | | |
Collapse
|
127
|
Liao SW, Yu TB, Guan Z. De Novo Design of Saccharide−Peptide Hydrogels as Synthetic Scaffolds for Tailored Cell Responses. J Am Chem Soc 2009; 131:17638-46. [DOI: 10.1021/ja907097t] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Affiliation(s)
- Sophia W. Liao
- Department of Biomedical Engineering, University of California, 3120 Natural Sciences 2, Irvine, California 92697-2715 and Department of Chemistry, University of California, 1102 Natural Sciences 2, Irvine, California 92697-2025
| | - Ting-Bin Yu
- Department of Biomedical Engineering, University of California, 3120 Natural Sciences 2, Irvine, California 92697-2715 and Department of Chemistry, University of California, 1102 Natural Sciences 2, Irvine, California 92697-2025
| | - Zhibin Guan
- Department of Biomedical Engineering, University of California, 3120 Natural Sciences 2, Irvine, California 92697-2715 and Department of Chemistry, University of California, 1102 Natural Sciences 2, Irvine, California 92697-2025
| |
Collapse
|
128
|
Yu Y, Cui S. Facile preparation of chemically cross-linked microgels by irradiation of visible light at room temperature. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2009; 25:11272-11275. [PMID: 19719163 DOI: 10.1021/la9026464] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
We report on the facile preparation of chemically cross-linked microgels in mild conditions by using the reversed microemulsion technique. Sodium alginate has been modified by partially grafting phenol groups to the backbone, on the basis of which microgels have been prepared by the irradiation of visible light in the presence of catalyst Ru(II) complex at room temperature. The irradiation of visible light instead of UV light or gamma rays brings many advantages. The mean diameters of the microgels are 15-40 microm in aqueous solution and 5-15 microm in the dried state. Although the size of the microgel is sensitive to the environment change, it presents excellent size stability in a broad range that covers the physiological condition. The applications of this biocompatible and biodegradable microgel in biology are greatly anticipated.
Collapse
Affiliation(s)
- You Yu
- Key Laboratory of Advanced Technologies of Materials (Ministry of Education), Southwest Jiaotong University, Chengdu 610031, China
| | | |
Collapse
|
129
|
Abraham S, Eroshenko N, Rao RR. Role of bioinspired polymers in determination of pluripotent stem cell fate. Regen Med 2009; 4:561-78. [PMID: 19580405 DOI: 10.2217/rme.09.23] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Human pluripotent stem cells, including embryonic and induced pluripotent stem cells, hold enormous potential for the treatment of many diseases, owing to their ability to generate cell types useful for therapeutic applications. Currently, many stem cell culture propagation and differentiation systems incorporate animal-derived components for promoting self-renewal and differentiation. However, use of these components is labor intensive, carries the risk of xenogeneic contamination and yields compromised experimental results that are difficult to duplicate. From a biomaterials perspective, the generation of an animal- and cell-free biomimetic microenvironment that provides the appropriate physical and chemical cues for stem cell self-renewal or differentiation into specialized cell types would be ideal. This review presents the use of natural and synthetic polymers that support propagation and differentiation of stem cells, in an attempt to obtain a clear understanding of the factors responsible for the determination of stem cell fate.
Collapse
Affiliation(s)
- Sheena Abraham
- Department of Chemical & Life Science Engineering, School of Engineering, Virginia Commonwealth University, Richmond, VA 23284, USA
| | | | | |
Collapse
|
130
|
Vrana NE, O'Grady A, Kay E, Cahill PA, McGuinness GB. Cell encapsulation within PVA-based hydrogels via freeze-thawing: a one-step scaffold formation and cell storage technique. J Tissue Eng Regen Med 2009; 3:567-72. [DOI: 10.1002/term.193] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
|
131
|
Bencherif SA, Washburn NR, Matyjaszewski K. Synthesis by AGET ATRP of Degradable Nanogel Precursors for In Situ Formation of Nanostructured Hyaluronic Acid Hydrogel. Biomacromolecules 2009; 10:2499-507. [DOI: 10.1021/bm9004639] [Citation(s) in RCA: 88] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Sidi A. Bencherif
- Department of Chemistry and Department of Biomedical Engineering, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213
| | - Newell R. Washburn
- Department of Chemistry and Department of Biomedical Engineering, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213
| | - Krzysztof Matyjaszewski
- Department of Chemistry and Department of Biomedical Engineering, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213
| |
Collapse
|
132
|
Chang Y, Xiao L, Tang Q. Preparation and characterization of a novel thermosensitive hydrogel based on chitosan and gelatin blends. J Appl Polym Sci 2009. [DOI: 10.1002/app.29954] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
|
133
|
Chu YF, Hsu CH, Soma PK, Lo YM. Immobilization of bioluminescent Escherichia coli cells using natural and artificial fibers treated with polyethyleneimine. BIORESOURCE TECHNOLOGY 2009; 100:3167-3174. [PMID: 19285859 DOI: 10.1016/j.biortech.2009.01.072] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/21/2008] [Revised: 01/12/2009] [Accepted: 01/20/2009] [Indexed: 05/27/2023]
Abstract
Biosensors based on whole-cell bioluminescence have the potential to become a cost-effective alternative to conventional detection methods upon validation of target selectivity and sensitivity. However, quantitative analysis of bioluminescence is greatly hindered due to lack of control over the total number of cells in a suspending culture. In this study, the effect of surface properties of genetically engineered luminous E. coli cells and fibrous matrices on the immobilization capacity and effectiveness under various environmental conditions were characterized. Four different fibers, including cotton, polyester, viscose rayon, and silk, were investigated. Although cell adhesion was observed on untreated viscose and cotton fibers, viscose fiber pretreated with 0.667% polyethyleneimine (PEI) was found capable of immobilizing the most viable E. coli DPD2234 cells, followed by viscose treated with 0.33% and 1% PEI. The cells immobilized on PEI-treated viscose remained viable and yielded 20% or more bioluminescence signals immediately upon contact with the inducer up to 72 h without feeding nutrients to the cells, suggesting that viscose treated with 0.667% PEI could provide a stable immobilization mechanism for bioluminescent E. coli cells with long sensing period, quick response time, and good signal reproducibility.
Collapse
Affiliation(s)
- Yi-Fang Chu
- Department of Animal and Food Sciences, University of Delaware, Newark, DE 19717, USA
| | | | | | | |
Collapse
|
134
|
Morimoto Y, Tan WH, Takeuchi S. Three-dimensional axisymmetric flow-focusing device using stereolithography. Biomed Microdevices 2009; 11:369-77. [PMID: 19009352 DOI: 10.1007/s10544-008-9243-y] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
This paper describes a three-dimensional microfluidic axisymmetric flow-focusing device (AFFD) fabricated using stereolithography. Using this method, we can fabricate AFFDs rapidly and automatically without cumbersome alignment needed in conventional methods. The AFFDs are able to be fabricated reproducibly with a micro-sized orifice of diameter around 250 mum. Using this device, we are able to produce monodisperse water-in-oil (W/O) droplets with a coefficient of variation (CV) of less than 4.5%, W/O droplets with encapsulated microbes (CV < 4.9%) and oil-in-water (O/W) droplets (CV < 3.2%) without any surface modifications. The diameter of these droplets range from 54 to 244 mum with respect to the flow rate ratio of the fluids used; these results are in good agreement with theoretical behavior. For applications of the AFFD, we demonstrate that these devices can be used to produce double emulsions and monodisperse hydrogel beads.
Collapse
Affiliation(s)
- Yuya Morimoto
- Center for International Research on MicroMechatronics (CIRMM), Institute of Industrial Science (IIS), The University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo 153-8505, Japan
| | | | | |
Collapse
|
135
|
Hunt NC, Shelton RM, Grover L. An alginate hydrogel matrix for the localised delivery of a fibroblast/keratinocyte co-culture. Biotechnol J 2009; 4:730-7. [DOI: 10.1002/biot.200800292] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
|
136
|
Metal Nanocrystals Embedded within Polymeric Nanostructures: Effect of Polymer-Metal Compound Interactions. Top Catal 2009. [DOI: 10.1007/s11244-008-9172-2] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
|
137
|
Oliveira JT, Martins L, Picciochi R, Malafaya PB, Sousa RA, Neves NM, Mano JF, Reis RL. Gellan gum: A new biomaterial for cartilage tissue engineering applications. J Biomed Mater Res A 2009; 93:852-63. [DOI: 10.1002/jbm.a.32574] [Citation(s) in RCA: 81] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
|
138
|
Pfluger CA, Carrier RL, Sun B, Ziemer KS, Burkey DD. Cross-Linking and Degradation Properties of Plasma Enhanced Chemical Vapor Deposited Poly(2-hydroxyethyl methacrylate). Macromol Rapid Commun 2008; 30:126-32. [PMID: 21706587 DOI: 10.1002/marc.200800647] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2008] [Accepted: 10/23/2008] [Indexed: 11/09/2022]
Abstract
Plasma Enhanced Chemical Vapor Deposition (PECVD) of poly-2-hydroxyethyl methacrylate (pHEMA) biocompatible, biodegradable polymer films were produced alone and cross-linked with ethylene glycol diacrylate (EGDA). Degree of cross-linking was controlled via manipulation of the EGDA flow rate, which influenced the amount of swelling and the extent of degradation of the films in an aqueous solution over time. Noncross-linked pHEMA films swelled 10% more than cross-linked films after 24 h of incubation in an aqueous environment. Increasing degree of film cross-linking decreased degradation over time. Thus, PECVD pHEMA films with variable cross-linking properties enable tuning of gel formation and degradation properties, making these films useful in a variety of biologically significant applications.
Collapse
Affiliation(s)
- Courtney A Pfluger
- Department of Chemical Engineering, Northeastern University, Boston, Massachusetts 02115, USA.
| | | | | | | | | |
Collapse
|
139
|
Cho NJ, Elazar M, Xiong A, Lee W, Chiao E, Baker J, Frank CW, Glenn JS. Viral infection of human progenitor and liver-derived cells encapsulated in three-dimensional PEG-based hydrogel. Biomed Mater 2008. [DOI: 10.1088/1748-6041/4/1/011001] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
|
140
|
Fierro S, Sánchez-Saavedra MDP, Copalcúa C. Nitrate and phosphate removal by chitosan immobilized Scenedesmus. BIORESOURCE TECHNOLOGY 2008; 99:1274-9. [PMID: 17531478 DOI: 10.1016/j.biortech.2007.02.043] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/26/2005] [Revised: 02/08/2007] [Accepted: 02/10/2007] [Indexed: 05/15/2023]
Abstract
The effect of chitosan immobilization of Scenedesmus spp. cells on its viability, growth and nitrate and phosphate uptake was investigated. Scenedesmus sp. (strains 1 and 2) and Scenedesmus obliquus immobilized in chitosan beads showed high viability after the immobilization process. Immobilized Scenedesmus sp. strain 1 had a higher growth rate than its free living counterpart. Nitrate and phosphate uptake by immobilized cells of Scenedesmus sp. (strain 1), freely suspended cells and blank chitosan beads (without cells) were evaluated. Immobilized cells accomplished a 70% nitrate and 94% phosphate removal within 12h of incubation while free-living cells removed 20% nitrate and 30% phosphate within 36 h of treatment. Blank chitosan beads were responsible for up to 20% nitrate and 60% phosphate uptake at the end of the experiment. Chitosan is a suitable matrix for immobilization of microalgae, particularly Scenedesmus sp., but this system should be improved before its application for water quality control.
Collapse
Affiliation(s)
- Sashenka Fierro
- Departamento de Acuicultura, Centro de Investigación y de Educación Superior de Ensenada (CICESE), Ensenada, 22860 Baja California, México
| | | | | |
Collapse
|
141
|
Plieva FM, Oknianska A, Degerman E, Mattiasson B. Macroporous gel particles as robust macroporous matrices for cell immobilization. Biotechnol J 2008; 3:410-7. [DOI: 10.1002/biot.200700134] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
|
142
|
Wong AP, Perez-Castillejos R, Christopher Love J, Whitesides GM. Partitioning microfluidic channels with hydrogel to construct tunable 3-D cellular microenvironments. Biomaterials 2008; 29:1853-61. [PMID: 18243301 DOI: 10.1016/j.biomaterials.2007.12.044] [Citation(s) in RCA: 159] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2007] [Accepted: 12/22/2007] [Indexed: 11/29/2022]
Abstract
Accurate modeling of the cellular microenvironment is important for improving studies of cell biology in vitro. Here, we demonstrate a flexible method for creating a cellular microenvironment in vitro that allows (i) controlled spatial distribution (patterning) of multiple types of cells within three-dimensional (3-D) matrices of a biologically derived, thermally curable hydrogel (Matrigel) and (ii) application of gradients of soluble factors, such as cytokines, across the hydrogel. The technique uses laminar flow to divide a microchannel into multiple subchannels separated by microslabs of hydrogel. It does not require the use of UV light or photoinitiators and is compatible with cell culture in the hydrogel. This technique makes it possible to design model systems to study cellular communication mediated by the diffusion of soluble factors within 3-D matrices. Such factors can originate either from secretions of neighboring cells patterned within the microchannel, or from an external source -- e.g., a solution of growth factors injected into a subchannel. This method is particularly useful for studying cells such as those of the immune system, which are often weakly adherent and difficult to position precisely with standard systems for cell culture. We demonstrated this application by co-culturing two types of macrophage-like cells (BAC1.2F5 and LADMAC cell lines) within spatially separated regions of a slab of hydrogel. This pair of cell lines represents a simple model system for intercellular communication: the LADMAC cells produce colony-stimulating factor 1 (CSF-1), which is required by the BAC cells for survival.
Collapse
Affiliation(s)
- Amy P Wong
- Harvard Biophysics Program, Harvard Medical School, Boston, MA 02115, USA
| | | | | | | |
Collapse
|
143
|
Mano J, Silva G, Azevedo H, Malafaya P, Sousa R, Silva S, Boesel L, Oliveira J, Santos T, Marques A, Neves N, Reis R. Natural origin biodegradable systems in tissue engineering and regenerative medicine: present status and some moving trends. J R Soc Interface 2008; 4:999-1030. [PMID: 17412675 PMCID: PMC2396201 DOI: 10.1098/rsif.2007.0220] [Citation(s) in RCA: 647] [Impact Index Per Article: 40.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
The fields of tissue engineering and regenerative medicine aim at promoting the regeneration of tissues or replacing failing or malfunctioning organs, by means of combining a scaffold/support material, adequate cells and bioactive molecules. Different materials have been proposed to be used as both three-dimensional porous scaffolds and hydrogel matrices for distinct tissue engineering strategies. Among them, polymers of natural origin are one of the most attractive options, mainly due to their similarities with the extracellular matrix (ECM), chemical versatility as well as typically good biological performance. In this review, the most studied and promising and recently proposed naturally derived polymers that have been suggested for tissue engineering applications are described. Different classes of such type of polymers and their blends with synthetic polymers are analysed, with special focus on polysaccharides and proteins, the systems that are more inspired by the ECM. The adaptation of conventional methods or non-conventional processing techniques for processing scaffolds from natural origin based polymers is reviewed. The use of particles, membranes and injectable systems from such kind of materials is also overviewed, especially what concerns the present status of the research that should lead towards their final application. Finally, the biological performance of tissue engineering constructs based on natural-based polymers is discussed, using several examples for different clinically relevant applications.
Collapse
Affiliation(s)
- J.F Mano
- 3B's Research Group—Biomaterials, Biodegradables and Biomimetics, Department of Polymer Engineering, University of Minho, Campus de Gualtar4710-057 Braga, Portugal
- IBB—Institute for Biotechnology and Bioengineering4710-057 Braga, Portugal
| | - G.A Silva
- 3B's Research Group—Biomaterials, Biodegradables and Biomimetics, Department of Polymer Engineering, University of Minho, Campus de Gualtar4710-057 Braga, Portugal
- IBB—Institute for Biotechnology and Bioengineering4710-057 Braga, Portugal
| | - H.S Azevedo
- 3B's Research Group—Biomaterials, Biodegradables and Biomimetics, Department of Polymer Engineering, University of Minho, Campus de Gualtar4710-057 Braga, Portugal
- IBB—Institute for Biotechnology and Bioengineering4710-057 Braga, Portugal
| | - P.B Malafaya
- 3B's Research Group—Biomaterials, Biodegradables and Biomimetics, Department of Polymer Engineering, University of Minho, Campus de Gualtar4710-057 Braga, Portugal
- IBB—Institute for Biotechnology and Bioengineering4710-057 Braga, Portugal
| | - R.A Sousa
- 3B's Research Group—Biomaterials, Biodegradables and Biomimetics, Department of Polymer Engineering, University of Minho, Campus de Gualtar4710-057 Braga, Portugal
- IBB—Institute for Biotechnology and Bioengineering4710-057 Braga, Portugal
| | - S.S Silva
- 3B's Research Group—Biomaterials, Biodegradables and Biomimetics, Department of Polymer Engineering, University of Minho, Campus de Gualtar4710-057 Braga, Portugal
- IBB—Institute for Biotechnology and Bioengineering4710-057 Braga, Portugal
| | - L.F Boesel
- 3B's Research Group—Biomaterials, Biodegradables and Biomimetics, Department of Polymer Engineering, University of Minho, Campus de Gualtar4710-057 Braga, Portugal
- IBB—Institute for Biotechnology and Bioengineering4710-057 Braga, Portugal
| | - J.M Oliveira
- 3B's Research Group—Biomaterials, Biodegradables and Biomimetics, Department of Polymer Engineering, University of Minho, Campus de Gualtar4710-057 Braga, Portugal
- IBB—Institute for Biotechnology and Bioengineering4710-057 Braga, Portugal
| | - T.C Santos
- 3B's Research Group—Biomaterials, Biodegradables and Biomimetics, Department of Polymer Engineering, University of Minho, Campus de Gualtar4710-057 Braga, Portugal
- IBB—Institute for Biotechnology and Bioengineering4710-057 Braga, Portugal
| | - A.P Marques
- 3B's Research Group—Biomaterials, Biodegradables and Biomimetics, Department of Polymer Engineering, University of Minho, Campus de Gualtar4710-057 Braga, Portugal
- IBB—Institute for Biotechnology and Bioengineering4710-057 Braga, Portugal
| | - N.M Neves
- 3B's Research Group—Biomaterials, Biodegradables and Biomimetics, Department of Polymer Engineering, University of Minho, Campus de Gualtar4710-057 Braga, Portugal
- IBB—Institute for Biotechnology and Bioengineering4710-057 Braga, Portugal
| | - R.L Reis
- 3B's Research Group—Biomaterials, Biodegradables and Biomimetics, Department of Polymer Engineering, University of Minho, Campus de Gualtar4710-057 Braga, Portugal
- IBB—Institute for Biotechnology and Bioengineering4710-057 Braga, Portugal
- Author for correspondence ()
| |
Collapse
|
144
|
Tan BH, Tam KC. Review on the dynamics and micro-structure of pH-responsive nano-colloidal systems. Adv Colloid Interface Sci 2008; 136:25-44. [PMID: 17707760 DOI: 10.1016/j.cis.2007.07.002] [Citation(s) in RCA: 112] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2007] [Revised: 07/05/2007] [Accepted: 07/05/2007] [Indexed: 11/30/2022]
Abstract
This review presents an overview on the research on pH-responsive microgel particles in the last 10 years. Microgels are cross-linked latex particles that are swollen in a good solvent. Significant quantitative studies have been conducted to investigate the swelling behavior (microscopic) and rheological (macroscopic) properties of the pH-responsive microgel particles as a function of neutralization degree, ionic strength, and cross-linked density. Mono-dispersed, alkali-swellable microgels containing carboxylic acid lattices, whose properties display extreme pH sensitivity in water is considered in detail in terms of swelling behavior and rheological properties. Their stability in solution and ability to undergo reversible volume phase transitions in response to pH makes them ideal model systems for the development of a semi-empirical as well as theoretical approach for predicting the viscosity of dilute and concentrated hard and soft sphere systems. The review concludes with a discussion of some recent applications of pH-responsive microgel particles.
Collapse
Affiliation(s)
- Beng H Tan
- School of Mechanical and Aerospace Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798, Singapore
| | | |
Collapse
|
145
|
Mathews DT, Birney YA, Cahill PA, McGuinness GB. Vascular cell viability on polyvinyl alcohol hydrogels modified with water-soluble and -insoluble chitosan. J Biomed Mater Res B Appl Biomater 2008; 84:531-40. [PMID: 17680667 DOI: 10.1002/jbm.b.30901] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Polyvinyl alcohol (PVA) hydrogels blended with chitosan or other biological macromolecules have shown promise for cell culture and tissue engineering. This study investigates the attachment and growth of bovine aortic endothelial (BAEC) and smooth muscle cells (BASMC) on the PVA hydrogels modified with water soluble and water insoluble chitosan. Cell adhesion on the surface of the membranes was examined by phase contrast microscopy while cell morphologies were studied using immunocytochemistry staining with EC and SMC specific biomarkers (F-actin and alpha actin respectively). Cells cultured on 6% PVA, 0.4% chitosan (water soluble and insoluble) hydrogel membranes displayed excellent adhesion and spreading characteristics, in addition to negligible cell structural morphological changes in comparison to a polystyrene control. Similar vascular cell adhesion features were apparent on PVA membranes blended with water-soluble and -insoluble chitosan. Fluorescent activated cell sorter (FACS) analysis was used to determine BAEC and BASMC proliferation and cell viability. Apoptotic levels in BAEC after 7 days were 12.8% +/- 2.5% on the PVA- chitosan WS-1 membrane and 10.1% +/- 1.5% on the control well (n = 3) while comparable results were also noted for BASMC. Equivalent proliferative activity was apparent for BAEC on the control and PVA-chitosan membrane after 7 days, while BASMC showed increased proliferative activity on the membranes. These results indicate that the PVA-chitosan blended hydrogel membranes show promise for cell culture and tissue engineering applications.
Collapse
Affiliation(s)
- D T Mathews
- School of Mechanical and Manufacturing Engineering, Dublin City University, Dublin 9, Ireland
| | | | | | | |
Collapse
|
146
|
El-Sherif H, El-Masry M. Biocatalytic hydrogels by template polymerization. POLYM ADVAN TECHNOL 2008. [DOI: 10.1002/pat.1011] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
|
147
|
Urciuolo F, Imparato G, Netti PA. Effect of dynamic loading on solute transport in soft gels implication for drug delivery. AIChE J 2008. [DOI: 10.1002/aic.11394] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
|
148
|
Román J, Cabañas MV, Peña J, Doadrio JC, Vallet-Regí M. An optimized β-tricalcium phosphate and agarose scaffold fabrication technique. J Biomed Mater Res A 2008; 84:99-107. [PMID: 17600331 DOI: 10.1002/jbm.a.31394] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Biodegradable scaffolds composed of beta-tricalcium phosphate, and a natural hydrogel, agarose, were prepared by a shaping method based on the thermal gelation of the polymeric component. This technique was modified to facilitate the inclusion, during the scaffold preparation stage, of therapeutic agents that could improve the graft performance. Vancomycin was included in materials containing different amounts of agarose and ceramic without affecting the scaffold consolidation process. These materials, easily injectable, behave like a reinforced hydrogel whose swelling behavior and drug release rate depend on their composition.
Collapse
Affiliation(s)
- J Román
- Departamento de Química Inorgánica y Bioinorgánica, Facultad de Farmacia, Universidad Complutense de Madrid, 28040 Madrid, Spain
| | | | | | | | | |
Collapse
|
149
|
Qin Y. The preparation and characterization of fiber reinforced alginate hydrogel. J Appl Polym Sci 2008. [DOI: 10.1002/app.27196] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
|
150
|
Kaihara S, Matsumura S, Fisher JP. Synthesis and characterization of cyclic acetal based degradable hydrogels. Eur J Pharm Biopharm 2008; 68:67-73. [PMID: 17888640 DOI: 10.1016/j.ejpb.2007.05.019] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2006] [Revised: 05/11/2007] [Accepted: 05/11/2007] [Indexed: 11/27/2022]
Abstract
While many synthetic, hydrolytically degradable hydrogels have been developed for biomedical applications, there are only a few examples whose polymer backbone does not form acidic products upon degradation. In order to address this concern, we proposed to develop a hydrogel based on a cyclic acetal unit that produces diols and propanals upon hydrolytic degradation. In particular, we proposed the fabrication of hydrogels formed by the free radical polymerization of two diacrylate monomers, 5-ethyl-5-(hydroxymethyl)-beta,beta-dimethyl-1,3-dioxane-2-ethanol diacrylate (EHD), a cyclic acetal having two acryl groups, and poly(ethylene glycol)diacrylate (PEGDA). However, the hydrophobicity of the EHD monomer inhibits hydrogel fabrication. Therefore this work develops a strategy to form hydrogels with a co-monomer system, one of which is hydrophobic, and subsequently describes the properties of the resulting hydrogel. Using benzoyl peroxide as an initiator and N,N-dimethyl-p-toluidine as an accelerator, the EHD and PEGDA monomers were reacted in an acetone/water co-solvent system. The chemical structure of the resulting EH-PEG [5-ethyl-5-(hydroxymethyl)-beta,beta-dimethyl-1,3-dioxane-2-ethanol-co-PEG] hydrogel was then characterized by FT-IR. Physicochemical properties of the EH-PEG hydrogel, including swelling degree, sol fraction, and contact angle, were determined so as to characterize the properties of these materials and ultimately investigate their use in drug delivery and tissue engineering applications. Results showed that EH-PEG hydrogel may be formed using the co-solvent system. Further results indicated that swelling degree is dependent upon initiator concentration, monomer concentration, and molar ratios of monomers, while sol fraction significantly depended on initiator concentration and monomer concentration, only. These results demonstrate the ability to fabricate hydrogels using EHD and PEGDA system as well as to control the properties of the resulting hydrophilic networks.
Collapse
Affiliation(s)
- Sachiko Kaihara
- Department of Applied Chemistry, Keio University, Yokohama, Japan
| | | | | |
Collapse
|