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Baker BM, Trappmann B, Wang WY, Sakar MS, Kim IL, Shenoy VB, Burdick JA, Chen CS. Cell-mediated fibre recruitment drives extracellular matrix mechanosensing in engineered fibrillar microenvironments. Nat Mater 2015; 14:1262-8. [PMID: 26461445 PMCID: PMC4654682 DOI: 10.1038/nmat4444] [Citation(s) in RCA: 347] [Impact Index Per Article: 38.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/10/2014] [Accepted: 08/28/2015] [Indexed: 05/17/2023]
Abstract
To investigate how cells sense stiffness in settings structurally similar to native extracellular matrices, we designed a synthetic fibrous material with tunable mechanics and user-defined architecture. In contrast to flat hydrogel surfaces, these fibrous materials recapitulated cell-matrix interactions observed with collagen matrices including stellate cell morphologies, cell-mediated realignment of fibres, and bulk contraction of the material. Increasing the stiffness of flat hydrogel surfaces induced mesenchymal stem cell spreading and proliferation; however, increasing fibre stiffness instead suppressed spreading and proliferation for certain network architectures. Lower fibre stiffness permitted active cellular forces to recruit nearby fibres, dynamically increasing ligand density at the cell surface and promoting the formation of focal adhesions and related signalling. These studies demonstrate a departure from the well-described relationship between material stiffness and spreading established with hydrogel surfaces, and introduce fibre recruitment as a previously undescribed mechanism by which cells probe and respond to mechanics in fibrillar matrices.
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Affiliation(s)
- Brendon M. Baker
- Tissue Microfabrication Lab, Department of Biomedical Engineering, Boston University, Boston, MA 02215
- Wyss Institute for Biologically Inspired Engineering, Center for Life Science Boston Building, 5th Floor, 3 Blackfan Circle, Boston, MA 02115
- Corresponding Authors: Christopher S. Chen, M.D., Ph.D., Department of Biomedical Engineering, Boston University, SLB201, 36 Cummington Mall, Boston, MA 02215, Phone: (617) 353-1699, Fax: (617) 353-6766, , Brendon M. Baker, Ph.D., Department of Biomedical Engineering, Boston University, SLB304, 36 Cummington Mall, Boston, MA 02215, Phone: (617) 353-1699, Fax: (617) 353-6766,
| | - Britta Trappmann
- Tissue Microfabrication Lab, Department of Biomedical Engineering, Boston University, Boston, MA 02215
- Wyss Institute for Biologically Inspired Engineering, Center for Life Science Boston Building, 5th Floor, 3 Blackfan Circle, Boston, MA 02115
| | - William Y. Wang
- Tissue Microfabrication Lab, Department of Biomedical Engineering, Boston University, Boston, MA 02215
| | - Mahmut S. Sakar
- Institute of Robotics and Intelligent Systems, Eidgenössische Technische Hochschule Zürich, CH-8092 Zürich, Switzerland
| | - Iris L. Kim
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA 19104
| | - Vivek B. Shenoy
- Department of Mechanical Engineering, University of Pennsylvania, Philadelphia, PA 19104
| | - Jason A. Burdick
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA 19104
| | - Christopher S. Chen
- Tissue Microfabrication Lab, Department of Biomedical Engineering, Boston University, Boston, MA 02215
- Wyss Institute for Biologically Inspired Engineering, Center for Life Science Boston Building, 5th Floor, 3 Blackfan Circle, Boston, MA 02115
- Corresponding Authors: Christopher S. Chen, M.D., Ph.D., Department of Biomedical Engineering, Boston University, SLB201, 36 Cummington Mall, Boston, MA 02215, Phone: (617) 353-1699, Fax: (617) 353-6766, , Brendon M. Baker, Ph.D., Department of Biomedical Engineering, Boston University, SLB304, 36 Cummington Mall, Boston, MA 02215, Phone: (617) 353-1699, Fax: (617) 353-6766,
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Kim IL, Pfeifer CG, Fisher MB, Saxena V, Meloni GR, Kwon MY, Kim M, Steinberg DR, Mauck RL, Burdick JA. Fibrous Scaffolds with Varied Fiber Chemistry and Growth Factor Delivery Promote Repair in a Porcine Cartilage Defect Model. Tissue Eng Part A 2015; 21:2680-90. [PMID: 26401910 DOI: 10.1089/ten.tea.2015.0150] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Current clinically approved methods for cartilage repair are generally based on either endogenous cell recruitment (e.g., microfracture) or chondrocyte delivery (e.g., autologous chondrocyte implantation). However, both methods culminate in repair tissue with inferior mechanical properties and the addition of biomaterials to these clinical interventions may improve their efficacy. To this end, the objective of this study was to investigate the ability of multipolymer acellular fibrous scaffolds to improve cartilage repair when combined with microfracture in a large animal (i.e., minipig) model. Composite scaffolds were formulated from a combination of hyaluronic acid (HA) fibers and poly(ɛ-caprolactone) (PCL) fibers, either with or without transforming growth factor-β3 (TGFβ3). After 12 weeks in vivo, material choice and TGFβ3 delivery had a significant impact on outcomes; specifically, PCL scaffolds without TGFβ3 had inferior gross appearance and reduced mechanical properties, whereas HA scaffolds that released TGFβ3 resulted in improved histological scores and increased type 2 collagen content. Importantly, analysis of the overall dataset revealed that histology, but not gross appearance, was a better predictor of mechanical properties. This study highlights the importance of scaffold properties on in vivo cartilage repair as well as the need for numerous quantitative outcome measures to fully evaluate treatment methods.
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Affiliation(s)
- Iris L Kim
- 1 Department of Bioengineering, University of Pennsylvania , Philadelphia, Pennsylvania.,2 Translational Musculoskeletal Research Center, Philadelphia VA Medical Center , Philadelphia, Pennsylvania
| | - Christian G Pfeifer
- 2 Translational Musculoskeletal Research Center, Philadelphia VA Medical Center , Philadelphia, Pennsylvania.,3 McKay Orthopaedic Research Laboratory, Department of Orthopaedic Surgery, Perelman School of Medicine, University of Pennsylvania , Philadelphia, Pennsylvania
| | - Matthew B Fisher
- 2 Translational Musculoskeletal Research Center, Philadelphia VA Medical Center , Philadelphia, Pennsylvania.,3 McKay Orthopaedic Research Laboratory, Department of Orthopaedic Surgery, Perelman School of Medicine, University of Pennsylvania , Philadelphia, Pennsylvania
| | - Vishal Saxena
- 2 Translational Musculoskeletal Research Center, Philadelphia VA Medical Center , Philadelphia, Pennsylvania.,3 McKay Orthopaedic Research Laboratory, Department of Orthopaedic Surgery, Perelman School of Medicine, University of Pennsylvania , Philadelphia, Pennsylvania
| | - Gregory R Meloni
- 2 Translational Musculoskeletal Research Center, Philadelphia VA Medical Center , Philadelphia, Pennsylvania.,3 McKay Orthopaedic Research Laboratory, Department of Orthopaedic Surgery, Perelman School of Medicine, University of Pennsylvania , Philadelphia, Pennsylvania
| | - Mi Y Kwon
- 1 Department of Bioengineering, University of Pennsylvania , Philadelphia, Pennsylvania
| | - Minwook Kim
- 2 Translational Musculoskeletal Research Center, Philadelphia VA Medical Center , Philadelphia, Pennsylvania.,3 McKay Orthopaedic Research Laboratory, Department of Orthopaedic Surgery, Perelman School of Medicine, University of Pennsylvania , Philadelphia, Pennsylvania
| | - David R Steinberg
- 2 Translational Musculoskeletal Research Center, Philadelphia VA Medical Center , Philadelphia, Pennsylvania.,3 McKay Orthopaedic Research Laboratory, Department of Orthopaedic Surgery, Perelman School of Medicine, University of Pennsylvania , Philadelphia, Pennsylvania
| | - Robert L Mauck
- 1 Department of Bioengineering, University of Pennsylvania , Philadelphia, Pennsylvania.,2 Translational Musculoskeletal Research Center, Philadelphia VA Medical Center , Philadelphia, Pennsylvania.,3 McKay Orthopaedic Research Laboratory, Department of Orthopaedic Surgery, Perelman School of Medicine, University of Pennsylvania , Philadelphia, Pennsylvania
| | - Jason A Burdick
- 1 Department of Bioengineering, University of Pennsylvania , Philadelphia, Pennsylvania.,2 Translational Musculoskeletal Research Center, Philadelphia VA Medical Center , Philadelphia, Pennsylvania
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Dong X, Zhang L, Liu Z, Yang M, Duan Z, Hou K, Liu B, Kim IL. MgCl2-supported TiCl4catalysts containing diethyl norbornene-2,3-dicarboxylate internal electron donor for 1-butene polymerization: Effects of internal electron donor configuration. J Appl Polym Sci 2014. [DOI: 10.1002/app.40758] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Xiaofang Dong
- School of Chemical Engineering and Technology; Hebei University of Technology; Tianjin 300130 China
| | - Li Zhang
- School of Chemical Engineering and Technology; Hebei University of Technology; Tianjin 300130 China
| | - Zhibo Liu
- School of Chemical Engineering and Technology; Hebei University of Technology; Tianjin 300130 China
| | - Min Yang
- School of Chemical Engineering and Technology; Hebei University of Technology; Tianjin 300130 China
| | - Zhongyu Duan
- School of Chemical Engineering and Technology; Hebei University of Technology; Tianjin 300130 China
| | - Kaihu Hou
- School of Chemical Engineering and Technology; Hebei University of Technology; Tianjin 300130 China
| | - Binyuan Liu
- School of Chemical Engineering and Technology; Hebei University of Technology; Tianjin 300130 China
| | - IL Kim
- BK21 PLUS Centre for Advanced Chemical Technology; Department of Polymer Science and Engineering; Pusan National University; Busan 609-735 Korea
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Purcell BP, Kim IL, Chuo V, Guinen T, Dorsey SM, Burdick JA. Incorporation of Sulfated Hyaluronic Acid Macromers into Degradable Hydrogel Scaffolds for Sustained Molecule Delivery. Biomater Sci 2014; 2:693-702. [PMID: 24955239 DOI: 10.1039/c3bm60227c] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Synthetically sulfated hyaluronic acid (HA) has been shown to bind proteins with high affinity through electrostatic interactions. While HA-based hydrogels have been used widely in recent years for drug delivery and tissue engineering applications, incorporation of sulfated HA into these networks to attenuate the release of proteins has yet to be explored. Here, we developed sulfated and methacrylate-modified HA macromers and incorporated them into HA hydrogels through free radical-initiated crosslinking. The sulfated HA macromers bound a heparin-binding protein (i.e., stromal cell-derived factor 1-α, SDF-1α) with an affinity comparable to heparin and did not alter the gelation behavior or network mechanics when copolymerized into hydrogels at low concentrations. Further, these macromers were incorporated into electrospun nanofibrous hydrogels to introduce sulfate groups into macroporous scaffolds. Once incorporated into either uniform or fibrous HA hydrogels, the sulfated HA macromers significantly slowed encapsulated SDF-1α release over 12 days. Thus, these macromers provide a useful way to introduce heparin-binding features into radically-crosslinked hydrogels to alter protein interactions for a range of applications.
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Affiliation(s)
- Brendan P Purcell
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA
| | - Iris L Kim
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA
| | - Vanessa Chuo
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA
| | - Theodore Guinen
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA
| | - Shauna M Dorsey
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA
| | - Jason A Burdick
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA
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Abstract
Aligned nanofibrous substrates can be created by electrospinning, but methods for creating multilamellar structures of aligned fibers are limited. Here, apposed nanofibrous scaffolds with pendant β-cyclodextrin (CD) were adhered together by adamantane (Ad) modified hyaluronic acid, exploiting the guest-host interactions of CD and Ad for macroscopic assembly. Stable user-defined multi-layered scaffolds were formed for cell culture or tissue engineering.
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Affiliation(s)
- Christopher B. Highley
- Department of Bioengineering, University of Pennsylvania, 240 Skirkanich Hall, 210 South 33 Street, Philadelphia, PA 19104, USA
| | - Christopher B. Rodell
- Department of Bioengineering, University of Pennsylvania, 240 Skirkanich Hall, 210 South 33 Street, Philadelphia, PA 19104, USA
| | - Iris L. Kim
- Department of Bioengineering, University of Pennsylvania, 240 Skirkanich Hall, 210 South 33 Street, Philadelphia, PA 19104, USA
| | - Ryan J. Wade
- Department of Bioengineering, University of Pennsylvania, 240 Skirkanich Hall, 210 South 33 Street, Philadelphia, PA 19104, USA
| | - J.A. Burdick
- Department of Bioengineering, University of Pennsylvania, 240 Skirkanich Hall, 210 South 33 Street, Philadelphia, PA 19104, USA
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Gramlich WM, Kim IL, Burdick JA. Synthesis and orthogonal photopatterning of hyaluronic acid hydrogels with thiol-norbornene chemistry. Biomaterials 2013; 34:9803-11. [PMID: 24060422 PMCID: PMC3830935 DOI: 10.1016/j.biomaterials.2013.08.089] [Citation(s) in RCA: 211] [Impact Index Per Article: 19.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2013] [Accepted: 08/30/2013] [Indexed: 11/26/2022]
Abstract
The patterning of chemical and mechanical signals within hydrogels permits added complexity towards their use as cell microenvironments for biomedical applications. Specifically, photopatterning is emerging to introduce heterogeneity in hydrogel properties; however, currently employed systems are limited in the range of properties that can be obtained, as well as in decoupling mechanical properties from changes in chemical signals. Here, we present an orthogonal photopatterning system that utilizes thiol-norbornene chemistry and permits extensive hydrogel modification, including with multiple signals, due to the number of reactive handles accessible for secondary reaction. Hyaluronic acid was functionalized with norbornene groups (NorHA) and reacted with di-thiols to create non-toxic hydrogels with a wide range of mechanical properties. For example, for 4 wt% NorHA at 20% modification, hydrogel mechanics from ≈ 1 kPa up to ≈ 70 kPa could be obtained by simply changing the amount of crosslinker. By limiting the initial extent of crosslinking, NorHA gels were synthesized with remaining pendent norbornene groups that could be reacted with thiol containing molecules in the presence of light and an initiator, including with spatial control. Secondary reactions with a di-thiol crosslinker changed mechanical properties, whereas reaction with mono-thiol peptides had no influence on the gel elastic modulus. This orthogonal chemistry was used sequentially to pattern multiple peptides into a single hydrogel, demonstrating the robustness of this system for the formation of complex hydrogels.
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Affiliation(s)
- William M. Gramlich
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Iris L. Kim
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Jason A. Burdick
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA 19104, USA
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Kim IL, Khetan S, Baker BM, Chen CS, Burdick JA. Fibrous hyaluronic acid hydrogels that direct MSC chondrogenesis through mechanical and adhesive cues. Biomaterials 2013; 34:5571-80. [PMID: 23623322 PMCID: PMC3652578 DOI: 10.1016/j.biomaterials.2013.04.004] [Citation(s) in RCA: 170] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2013] [Accepted: 04/03/2013] [Indexed: 12/15/2022]
Abstract
Electrospinning has recently gained much interest due to its ability to form scaffolds that mimic the nanofibrous nature of the extracellular matrix, such as the size and depth-dependent alignment of collagen fibers within hyaline cartilage. While much progress has been made in developing bulk, isotropic hydrogels for tissue engineering and understanding how the microenvironment of such scaffolds affects cell response, these effects have not been extensively studied in a nanofibrous system. Here, we show that the mechanics (through intrafiber crosslink density) and adhesivity (through RGD density) of electrospun hyaluronic acid (HA) fibers significantly affect human mesenchymal stem cell (hMSC) interactions and gene expression. Specifically, hMSC spreading, proliferation, and focal adhesion formation were dependent on RGD density, but not on the range of fiber mechanics investigated. Moreover, traction-mediated fiber displacements generally increased with more adhesive fibers. The expression of chondrogenic markers, unlike trends in cell spreading and cytoskeletal organization, was influenced by both fiber mechanics and adhesivity, in which softer fibers and lower RGD densities generally enhanced chondrogenesis. This work not only reveals concurrent effects of mechanics and adhesivity in a fibrous context, but also highlights fibrous HA hydrogels as a promising scaffold for future cartilage repair strategies.
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Affiliation(s)
- Iris L. Kim
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA [Tel: 215-898-8537; Fax: 215-573-2071]
| | - Sudhir Khetan
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA [Tel: 215-898-8537; Fax: 215-573-2071]
| | - Brendon M. Baker
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA [Tel: 215-898-8537; Fax: 215-573-2071]
| | - Christopher S. Chen
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA [Tel: 215-898-8537; Fax: 215-573-2071]
| | - Jason A. Burdick
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA [Tel: 215-898-8537; Fax: 215-573-2071]
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Lu HD, Soranno DE, Rodell CB, Kim IL, Burdick JA. Secondary photocrosslinking of injectable shear-thinning dock-and-lock hydrogels. Adv Healthc Mater 2013; 2:1028-36. [PMID: 23299998 DOI: 10.1002/adhm.201200343] [Citation(s) in RCA: 69] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2012] [Revised: 10/26/2012] [Indexed: 01/09/2023]
Abstract
Shear-thinning hydrogels are useful in numerous applications, including as injectable carriers that act as scaffolds to support cell and drug therapies. Here, we describe the engineering of a self-assembling Dock-and-Lock (DnL) system that forms injectable shear-thinning hydrogels using molecular recognition interactions that also possess photo-triggerable secondary crosslinks. These DnL hydrogels are fabricated from peptide-modified hyaluronic acid (HA) and polypeptide precursors, can self-heal immediately after shear induced flow, are cytocompatible, and can be stabilized through light-initiated radical polymerization of methacrylate functional groups to tune gel mechanics and erosion kinetics. Secondary crosslinked hydrogels retain self-adhesive properties and exhibit cooperative physical and chemical crosslinks with moduli as high as ∼10 times larger than moduli of gels based on physical crosslinking alone. The extent of reaction and change in properties are dependent on whether the methacrylate is incorporated either at the terminus of the peptide or directly to the HA backbone. Additionally, the gel erosion can be monitored through an incorporated fluorophore and physical-chemical gels remain intact in solution over months, whereas physical gels that are not covalently crosslinked erode completely within days. Mesenchymal stem cells exhibit increased viability when cultured in physical- chemical gels, compared with those cultured in gels based on physical crosslinks alone. The physical properties of these DnL gels may be additionally tuned by adjusting component compositions, which allows DnL gels with a wide range of physical properties to be constructed for use.
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Affiliation(s)
- Hoang D Lu
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA 19104, USA
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Lee SW, Tettey KE, Kim IL, Burdick JA, Lee D. Controlling the Cell-Adhesion Properties of Poly(acrylic acid)/Polyacrylamide Hydrogen-Bonded Multilayers. Macromolecules 2012. [DOI: 10.1021/ma301025a] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Affiliation(s)
- Sang-Wook Lee
- Department
of Chemical and Biomolecular Engineering and ‡Department of Bioengineering, University of Pennsylvania, Philadelphia,
Pennsylvania 19104, United States
| | - Kwadwo E. Tettey
- Department
of Chemical and Biomolecular Engineering and ‡Department of Bioengineering, University of Pennsylvania, Philadelphia,
Pennsylvania 19104, United States
| | - Iris L. Kim
- Department
of Chemical and Biomolecular Engineering and ‡Department of Bioengineering, University of Pennsylvania, Philadelphia,
Pennsylvania 19104, United States
| | - Jason A. Burdick
- Department
of Chemical and Biomolecular Engineering and ‡Department of Bioengineering, University of Pennsylvania, Philadelphia,
Pennsylvania 19104, United States
| | - Daeyeon Lee
- Department
of Chemical and Biomolecular Engineering and ‡Department of Bioengineering, University of Pennsylvania, Philadelphia,
Pennsylvania 19104, United States
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Lu HD, Charati MB, Kim IL, Burdick JA. Injectable shear-thinning hydrogels engineered with a self-assembling Dock-and-Lock mechanism. Biomaterials 2012; 33:2145-53. [DOI: 10.1016/j.biomaterials.2011.11.076] [Citation(s) in RCA: 154] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2011] [Accepted: 11/28/2011] [Indexed: 01/06/2023]
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Kim IL, Mauck RL, Burdick JA. Hydrogel design for cartilage tissue engineering: a case study with hyaluronic acid. Biomaterials 2011; 32:8771-82. [PMID: 21903262 DOI: 10.1016/j.biomaterials.2011.08.073] [Citation(s) in RCA: 336] [Impact Index Per Article: 25.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2011] [Accepted: 08/23/2011] [Indexed: 11/16/2022]
Abstract
Hyaline cartilage serves as a low-friction and wear-resistant articulating surface in load-bearing, diarthrodial joints. Unfortunately, as the avascular, alymphatic nature of cartilage significantly impedes the body's natural ability to regenerate, damage resulting from trauma and osteoarthritis necessitates repair attempts. Current clinical methods are generally limited in their ability to regenerate functional cartilage, and so research in recent years has focused on tissue engineering solutions in which the regeneration of cartilage is pursued through combinations of cells (e.g., chondrocytes or stem cells) paired with scaffolds (e.g., hydrogels, sponges, and meshes) in conjunction with stimulatory growth factors and bioreactors. A variety of synthetic and natural materials have been employed, most commonly in the form of hydrogels, and these systems have been tuned for optimal nutrient diffusion, connectivity of deposited matrix, degradation, soluble factor delivery, and mechanical loading for enhanced matrix production and organization. Even with these promising advances, the complex mechanical properties and biochemical composition of native cartilage have not been achieved, and engineering cartilage tissue still remains a significant challenge. Using hyaluronic acid hydrogels as an example, this review will follow the progress of material design specific to cartilage tissue engineering and propose possible future directions for the field.
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Affiliation(s)
- Iris L Kim
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA 19104, USA
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Kim EM, Bang SY, Kim IL, Shin HD, Park BL, Lee HS, Bae SC. Different genetic effect of PXK on systemic lupus erythematosus in the Korean population. Rheumatol Int 2011; 32:277-80. [DOI: 10.1007/s00296-010-1789-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2010] [Accepted: 12/30/2010] [Indexed: 11/30/2022]
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