Research Article
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Published Online: 17 July 2013

A Facile Method to Fabricate Hydrogels with Microchannel-Like Porosity for Tissue Engineering

Publication: Tissue Engineering Part C: Methods
Volume 20, Issue Number 2

Abstract

Hydrogels are widely used as three-dimensional (3D) tissue engineering scaffolds due to their tissue-like water content, as well as their tunable physical and chemical properties. Hydrogel-based scaffolds are generally associated with nanoscale porosity, whereas macroporosity is highly desirable to facilitate nutrient transfer, vascularization, cell proliferation and matrix deposition. Diverse techniques have been developed for introducing macroporosity into hydrogel-based scaffolds. However, most of these methods involve harsh fabrication conditions that are not cell friendly, result in spherical pore structure, and are not amenable for dynamic pore formation. Human tissues contain abundant microchannel-like structures, such as microvascular network and nerve bundles, yet fabricating hydrogels containing microchannel-like pore structures remains a great challenge. To overcome these limitations, here we aim to develop a facile, cell-friendly method for engineering hydrogels with microchannel-like porosity using stimuli-responsive microfibers as porogens. Microfibers with sizes ranging 150–200 μm were fabricated using a coaxial flow of alginate and calcium chloride solution. Microfibers containing human embryonic kidney (HEK) cells were encapsulated within a 3D gelatin hydrogel, and then exposed to ethylenediaminetetraacetic acid (EDTA) solution at varying doses and duration. Scanning electron microscopy confirmed effective dissolution of alginate microfibers after EDTA treatment, leaving well-defined, interconnected microchannel structures within the 3D hydrogels. Upon release from the alginate fibers, HEK cells showed high viability and enhanced colony formation along the luminal surfaces of the microchannels. In contrast, HEK cells in non-EDTA treated control exhibited isolated cells, which remained entrapped in alginate microfibers. Together, our results showed a facile, cell-friendly process for dynamic microchannel formation within hydrogels, which may simultaneously release cells in 3D hydrogels in a spatiotemporally controlled manner. This platform may be adapted to include other cell-friendly stimuli for porogen removal, such as Matrix metalloproteinase-sensitive peptides or photodegradable gels. While we used HEK cells in this study as proof of principle, the concept described in this study may also be used for releasing clinically relevant cell types, such as smooth muscle and endothelial cells that are useful for repairing tissues involving tubular structures.

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References

1.
Nguyen K.T., and West J.L. Photopolymerizable hydrogels for tissue engineering applications. Biomaterials 23, 4307, 2002.
2.
Langer R., and Vacanti J.P. Tissue engineering. Science 260, 920, 1993.
3.
Mosiewicz K.A., Johnsson K., and Lutolf M.P. Phosphopantetheinyl transferase-catalyzed formation of bioactive hydrogels for tissue engineering. J Am Chem Soc 132, 5972, 2010.
4.
DeForest C.A., Polizzotti B.D., and Anseth K.S. Sequential click reactions for synthesizing and patterning three-dimensional cell microenvironments. Nat Mater 8, 659, 2009.
5.
Flaim C.J., Chien S., and Bhatia S.N. An extracellular matrix microarray for probing cellular differentiation. Nat Methods 2, 119, 2005.
6.
Chan A.W., and Neufeld R.J. Modeling the controllable pH-responsive swelling and pore size of networked alginate based biomaterials. Biomaterials 30, 6119, 2009.
7.
Chan A.W., and Neufeld R.J. Tuneable semi-synthetic network alginate for absorptive encapsulation and controlled release of protein therapeutics. Biomaterials 31, 9040, 2010.
8.
Hollister S.J. Porous scaffold design for tissue engineering. Nat Mater 4, 518, 2005.
9.
Peppas N.A., Hilt J.Z., Khademhosseini A., and Langer R. Hydrogels in biology and medicine: from molecular principles to bionanotechnology. Adv Mater 18, 1345, 2006.
10.
Khademhosseini A., and Langer R. Microengineered hydrogels for tissue engineering. Biomaterials 28, 5087, 2007.
11.
Nichol J.W., and Khademhosseini A. Modular tissue engineering: engineering biological tissues from the bottom up. Soft Matter 5, 1312, 2009.
12.
Rouwkema J., Rivron N.C., and van Blitterswijk C.A. Vascularization in tissue engineering. Trends Biotechnol 26, 434, 2008.
13.
McGuigan A.P., and Sefton M.V. Vascularized organoid engineered by modular assembly enables blood perfusion. Proc Natl Acad Sci U S A 103, 11461, 2006.
14.
Reneker D.H., and Chun I. Nanometre diameter fibres of polymer, produced by electrospinning. Nanotechnology 7, 216, 1996.
15.
Yoshimoto H., Shin Y.M., Terai H., and Vacanti J.P. A biodegradable nanofiber scaffold by electrospinning and its potential for bone tissue engineering. Biomaterials 24, 2077, 2003.
16.
Xiao J., Duan H., Liu Z., Wu Z., Lan Y., Zhang W., et al. Construction of the recellularized corneal stroma using porous acellular corneal scaffold. Biomaterials 32, 6962, 2011.
17.
Choi S.W., Yeh Y.C., Zhang Y., Sung H.W., and Xia Y. Uniform beads with controllable pore sizes for biomedical applications. Small 6, 1492, 2010.
18.
Salerno A., Guarnieri D., Iannone M., Zeppetelli S., and Netti P.A. Effect of micro- and macroporosity of bone tissue three-dimensional-poly(epsilon-caprolactone) scaffold on human mesenchymal stem cells invasion, proliferation, and differentiation in vitro. Tissue Eng Part A 16, 2661, 2010.
19.
Fozdar D.Y., Soman P., Lee J.W., Han L.H., and Chen S. Three-dimensional polymer constructs exhibiting a tunable negative Poisson's ratio. Adv Funct Mater 21, 2712, 2011.
20.
Ovsianikov A., Schlie S., Ngezahayo A., Haverich A., and Chichkov B.N. Two-photon polymerization technique for microfabrication of CAD-designed 3D scaffolds from commercially available photosensitive materials. J Tissue Eng Regen Med 1, 443, 2007.
21.
Arcaute K., Mann B.K., and Wicker R.B. Stereolithography of three-dimensional bioactive poly(ethylene glycol) constructs with encapsulated cells. Ann Biomed Eng 34, 1429, 2006.
22.
Tsang V.L., and Bhatia S.N. Three-dimensional tissue fabrication. Adv Drug Deliv Rev 56, 1635, 2004.
23.
Houchin-Ray T., Swift L.A., Jang J.H., and Shea L.D. Patterned PLG substrates for localized DNA delivery and directed neurite extension. Biomaterials 28, 2603, 2007.
24.
Hong Y., Guan J., Fujimoto K.L., Hashizume R., Pelinescu A.L., and Wagner W.R. Tailoring the degradation kinetics of poly(ester carbonate urethane)urea thermoplastic elastomers for tissue engineering scaffolds. Biomaterials 31, 4249, 2010.
25.
Chen V.J., and Ma P.X. Nano-fibrous poly(L-lactic acid) scaffolds with interconnected spherical macropores. Biomaterials 25, 2065, 2004.
26.
Hwang C.M., Sant S., Masaeli M., Kachouie N.N., Zamanian B., Lee S.H., et al. Fabrication of three-dimensional porous cell-laden hydrogel for tissue engineering. Biofabrication 2, 035003, 2010.
27.
Scott E.A., Nichols M.D., Kuntz-Willits R., and Elbert D.L. Modular scaffolds assembled around living cells using poly(ethylene glycol) microspheres with macroporation via a non-cytotoxic porogen. Acta Biomater 6, 29, 2010.
28.
Niino T., Hamajima D., Montagne K., Oizumi S., Naruke H., Huang H., et al. Laser sintering fabrication of three-dimensional tissue engineering scaffolds with a flow channel network. Biofabrication 3, 034104, 2011.
29.
Suri S., and Schmidt C.E. Cell-laden hydrogel constructs of hyaluronic acid, collagen, and laminin for neural tissue engineering. Tissue Eng Part A 16, 1703, 2010.
30.
Chew S.Y., Mi R., Hoke A., and Leong K.W. Aligned protein-polymer composite fibers enhance nerve regeneration: a potential tissue-engineering platform. Adv Funct Mater 17, 1288, 2007.
31.
Miller J.S., Stevens K.R., Yang M.T., Baker B.M., Nguyen D.H., Cohen D.M., et al. Rapid casting of patterned vascular networks for perfusable engineered three-dimensional tissues. Nat Mater 11, 768, 2012.
32.
Radisic M., Yang L., Boublik J., Cohen R.J., Langer R., Freed L.E., et al. Medium perfusion enables engineering of compact and contractile cardiac tissue. Am J Physiol Heart Circ Physiol 286, H507, 2004.
33.
Chrobak K.M., Potter D.R., and Tien J. Formation of perfused, functional microvascular tubes in vitro. Microvasc Res 71, 185, 2006.
34.
Lynam D., Bednark B., Peterson C., Welker D., Gao M., and Sakamoto J.S. Precision microchannel scaffolds for central and peripheral nervous system repair. J Mater Sci Mater Med 22, 2119, 2011.
35.
Nichol J.W., Koshy S.T., Bae H., Hwang C.M., Yamanlar S., and Khademhosseini A. Cell-laden microengineered gelatin methacrylate hydrogels. Biomaterials 31, 5536, 2010.
36.
Golden A.P., and Tien J. Fabrication of microfluidic hydrogels using molded gelatin as a sacrificial element. Lab Chip 7, 720, 2007.
37.
Ling Y., Rubin J., Deng Y., Huang C., Demirci U., Karp J.M., et al. A cell-laden microfluidic hydrogel. Lab Chip 7, 756, 2007.
38.
Choi N.W., Cabodi M., Held B., Gleghorn J.P., Bonassar L.J., and Stroock A.D. Microfluidic scaffolds for tissue engineering. Nat Mater 6, 908, 2007.
39.
Cuchiara M.P., Allen A.C., Chen T.M., Miller J.S., and West J.L. Multilayer microfluidic PEGDA hydrogels. Biomaterials 31, 5491, 2010.
40.
Visconti R.P., Kasyanov V., Gentile C., Zhang J., Markwald R.R., and Mironov V. Towards organ printing: engineering an intra-organ branched vascular tree. Expert Opin Biol Ther 10, 409, 2010.
41.
Mondrinos M.J., Dembzynski R., Lu L., Byrapogu V.K., Wootton D.M., Lelkes P.I., et al. Porogen-based solid freeform fabrication of polycaprolactone-calcium phosphate scaffolds for tissue engineering. Biomaterials 27, 4399, 2006.
42.
Han L.H., Lai J.H., Yu S., and Yang F. Dynamic tissue engineering scaffolds with stimuli-responsive macroporosity formation. Biomaterials 34, 4251, 2013.
43.
Fairbanks B.D., Schwartz M.P., Bowman C.N., and Anseth K.S. Photoinitiated polymerization of PEG-diacrylate with lithium phenyl-2,4,6-trimethylbenzoylphosphinate: polymerization rate and cytocompatibility. Biomaterials 30, 6702, 2009.
44.
Shin S.J., Park J.Y., Lee J.Y., Park H., Park Y.D., Lee K.B., et al. “On the fly” continuous generation of alginate fibers using a microfluidic device. Langmuir 23, 9104, 2007.
45.
Graham F.L., Smiley J., Russell W.C., and Nairn R. Characteristics of a human cell line transformed by DNA from human adenovirus type 5. J Gen virol 36, 59, 1977.
46.
Bellan L.M., Pearsall M., Cropek D.M., and Langer R. A 3D interconnected microchannel network formed in gelatin by sacrificial shellac microfibers. Adv Mater 24, 5187, 2012.
47.
Anderson S.B., Lin C.C., Kuntzler D.V., and Anseth K.S. The performance of human mesenchymal stem cells encapsulated in cell-degradable polymer-peptide hydrogels. Biomaterials 32, 3564, 2011.
48.
Lutolf M.P., Lauer-Fields J.L., Schmoekel H.G., Metters A.T., Weber F.E., Fields G.B., et al. Synthetic matrix metalloproteinase-sensitive hydrogels for the conduction of tissue regeneration: engineering cell-invasion characteristics. Proc Natl Acad Sci U S A 100, 5413, 2003.

Information & Authors

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Published In

cover image Tissue Engineering Part C: Methods
Tissue Engineering Part C: Methods
Volume 20Issue Number 2February 2014
Pages: 169 - 176
PubMed: 23745610

History

Published in print: February 2014
Published online: 17 July 2013
Published ahead of production: 7 June 2013
Accepted: 29 May 2013
Received: 17 March 2013

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Joshua Hammer, BSc
*
School of Biological and Health Systems Engineering, Arizona State University, Tempe, Arizona.
Li-Hsin Han, PhD*
Department of Orthopaedic Surgery, Stanford University, Stanford, California.
Xinming Tong, PhD
Department of Orthopaedic Surgery, Stanford University, Stanford, California.
Fan Yang, PhD
Department of Orthopaedic Surgery, Stanford University, Stanford, California.
Department of Bioengineering, Stanford University, Stanford, California.

Notes

Address correspondence to:Fan Yang, PhDDepartment of BioengineeringStanford University300 Pasteur DriveEdwards R105, MC5341Stanford, CA 94305E-mail: [email protected]

Disclosure Statement

This work has been disclosed to the Office of Technology Licensing at Stanford University.

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