Photocrosslinkable laminin-functionalized polyethylene glycol hydrogel for intervertebral disc regeneration.

Intervertebral disc (IVD) disorders and age-related degeneration are believed to contribute to lower back pain. There is significant interest in cell-based strategies for regenerating the nucleus pulposus (NP) region of the disc; however, few scaffolds have been evaluated for their ability to promote or maintain an immature NP cell phenotype. Previous studies have shown that NP cell-laminin interactions promote cell adhesion and biosynthesis, which suggests a laminin-functionalized biomaterial may be useful for promoting or maintaining the NP cell phenotype. Here, a photocrosslinkable poly(ethylene glycol)-laminin 111 (PEG-LM111) hydrogel was developed. The mechanical properties of PEG-LM111 hydrogel could be tuned within the range of dynamic shear moduli values previously reported for human NP. When primary immature porcine NP cells were seeded onto PEG-LM111 hydrogels of varying stiffnesses, LM111-presenting hydrogels were found to promote cell clustering and increased levels of sGAG production as compared to stiffer LM111-presenting and PEG-only gels. When cells were encapsulated in 3-D gels, hydrogel formulation was found to influence NP cell metabolism and expression of proposed NP phenotypic markers, with higher expression of N-cadherin and cytokeratin 8 observed for cells cultured in softer (<1kPa) PEG-LM111 hydrogels. Overall, these findings suggest that soft, LM111-functionalized hydrogels may promote or maintain the expression of specific markers characteristic of an immature NP cell phenotype.

[1]  Van C. Mow,et al.  Is the Nucleus Pulposus a Solid or a Fluid? Mechanical Behaviors of the Nucleus Pulposus of the Human Intervertebral Disc , 1996, Spine.

[2]  H. Gruber,et al.  Cell-based tissue engineering for the intervertebral disc: in vitro studies of human disc cell gene expression and matrix production within selected cell carriers. , 2004, The spine journal : official journal of the North American Spine Society.

[3]  J. Urban,et al.  Differential expression level of cytokeratin 8 in cells of the bovine nucleus pulposus complicates the search for specific intervertebral disc cell markers , 2010, Arthritis research & therapy.

[4]  S. Eisenstein,et al.  Biochemical changes in intervertebral disc degeneration. , 1981, Biochimica et biophysica acta.

[5]  Christopher J Hunter,et al.  The Functional Significance of Cell Clusters in the Notochordal Nucleus Pulposus: Survival and Signaling in the Canine Intervertebral Disc , 2004, Spine.

[6]  T. Oegema,et al.  Notochordal cells interact with nucleus pulposus cells: regulation of proteoglycan synthesis. , 1999, Experimental cell research.

[7]  S. Nicoll,et al.  Photo-crosslinked alginate hydrogels support enhanced matrix accumulation by nucleus pulposus cells in vivo. , 2009, Osteoarthritis and cartilage.

[8]  Wan-Ju Li,et al.  Intervertebral disc tissue engineering using a novel hyaluronic acid-nanofibrous scaffold (HANFS) amalgam. , 2008, Tissue engineering. Part A.

[9]  F. Guilak,et al.  Monolayer cell expansion conditions affect the chondrogenic potential of adipose‐derived stem cells , 2008, Biotechnology and bioengineering.

[10]  Cari M Whyne,et al.  A Novel Thiol-Modified Hyaluronan and Elastin-Like Polypetide Composite Material for Tissue Engineering of the Nucleus Pulposus of the Intervertebral Disc , 2011, Spine.

[11]  P. Lonai,et al.  Expression and biological role of laminin-1. , 2003, Matrix biology : journal of the International Society for Matrix Biology.

[12]  Lawrence J. Bonassar,et al.  Tissue-engineered intervertebral discs produce new matrix, maintain disc height, and restore biomechanical function to the rodent spine , 2011, Proceedings of the National Academy of Sciences.

[13]  Ruth M Ripley,et al.  Metabolism of the Intervertebral Disc: Effects of Low Levels of Oxygen, Glucose, and pH on Rates of Energy Metabolism of Bovine Nucleus Pulposus Cells , 2005, Spine.

[14]  George M. Wahba,et al.  Intervertebral Disc Cell Therapy for Regeneration: Mesenchymal Stem Cell Implantation in Rat Intervertebral Discs , 2004, Annals of Biomedical Engineering.

[15]  M. Aebi,et al.  The human lumbar intervertebral disc: evidence for changes in the biosynthesis and denaturation of the extracellular matrix with growth, maturation, ageing, and degeneration. , 1996, The Journal of clinical investigation.

[16]  J. Ralphs,et al.  The development of fibrocartilage in the rat intervertebral disc , 1995, Anatomy and Embryology.

[17]  S. Nicoll,et al.  Characterization of novel photocrosslinked carboxymethylcellulose hydrogels for encapsulation of nucleus pulposus cells. , 2010, Acta biomaterialia.

[18]  P. Roughley,et al.  The potential of chitosan-based gels containing intervertebral disc cells for nucleus pulposus supplementation. , 2006, Biomaterials.

[19]  C. Gilchrist,et al.  Functional integrin subunits regulating cell–matrix interactions in the intervertebral disc , 2007, Journal of orthopaedic research : official publication of the Orthopaedic Research Society.

[20]  Lori A. Setton,et al.  Molecular phenotypes of notochordal cells purified from immature nucleus pulposus , 2006, European Spine Journal.

[21]  Dawn M. Elliott,et al.  Material properties in unconfined compression of human nucleus pulposus, injectable hyaluronic acid-based hydrogels and tissue engineering scaffolds , 2007, European Spine Journal.

[22]  L. Setton,et al.  Early metabolite levels predict long-term matrix accumulation for chondrocytes in elastin-like polypeptide biopolymer scaffolds. , 2009, Tissue engineering. Part A.

[23]  L. Setton,et al.  Conditioned Medium Differentially Regulates Matrix Protein Gene Expression in Cells of the Intervertebral Disc , 2004, Spine.

[24]  Sally Roberts,et al.  Degeneration of the intervertebral disc , 2003, Arthritis research & therapy.

[25]  D. Seliktar,et al.  Biosynthetic hydrogel scaffolds made from fibrinogen and polyethylene glycol for 3D cell cultures. , 2005, Biomaterials.

[26]  C. Gilchrist,et al.  Expression of laminin isoforms, receptors, and binding proteins unique to nucleus pulposus cells of immature intervertebral disc. , 2009, Connective tissue research.

[27]  W. Erwin,et al.  Notochord Cells Regulate Intervertebral Disc Chondrocyte Proteoglycan Production and Cell Proliferation , 2006, Spine.

[28]  Pierre Weiss,et al.  An injectable vehicle for nucleus pulposus cell-based therapy. , 2011, Biomaterials.

[29]  J. Miner,et al.  Laminin functions in tissue morphogenesis. , 2004, Annual review of cell and developmental biology.

[30]  D. Sakai,et al.  A phenotypic comparison of intervertebral disc and articular cartilage cells in the rat , 2007, European Spine Journal.

[31]  D. Sakai,et al.  Differential Phenotype of Intervertebral Disc Cells: Microarray and Immunohistochemical Analysis of Canine Nucleus Pulposus and Anulus Fibrosus , 2009, Spine.

[32]  G. Fischer,et al.  Intermediate filament typing of the human embryonic and fetal notochord , 1995, Cell and Tissue Research.

[33]  M. Alini,et al.  Thermoreversible hyaluronan-based hydrogel supports in vitro and ex vivo disc-like differentiation of human mesenchymal stem cells. , 2013, The spine journal : official journal of the North American Spine Society.

[34]  J. Hubbell,et al.  Characterization of permeability and network structure of interfacially photopolymerized poly(ethylene glycol) diacrylate hydrogels. , 1998, Biomaterials.

[35]  M. Cohn,et al.  Identification of nucleus pulposus precursor cells and notochordal remnants in the mouse: Implications for disk degeneration and chordoma formation , 2008, Developmental dynamics : an official publication of the American Association of Anatomists.

[36]  A. Freemont,et al.  Human mesenchymal stem cell differentiation to NP-like cells in chitosan-glycerophosphate hydrogels. , 2008, Biomaterials.

[37]  V C Mow,et al.  The viscoelastic behavior of the non-degenerate human lumbar nucleus pulposus in shear. , 1997, Journal of biomechanics.

[38]  Kenneth M. Yamada,et al.  Taking Cell-Matrix Adhesions to the Third Dimension , 2001, Science.

[39]  R. Mutter,et al.  Emergency Department Visits and Inpatient Stays Related to Back Problems, 2008 , 2011 .

[40]  Charles A Vacanti,et al.  Tissue-Engineered Composites of Anulus Fibrosus and Nucleus Pulposus for Intervertebral Disc Replacement , 2004, Spine.

[41]  Xinyan Tang,et al.  Changes in the Molecular Phenotype of Nucleus Pulposus Cells with Intervertebral Disc Aging , 2012, PloS one.

[42]  J. Ralphs,et al.  Role of actin stress fibres in the development of the intervertebral disc: Cytoskeletal control of extracellular matrix assembly , 1999, Developmental dynamics : an official publication of the American Association of Anatomists.

[43]  Junmin Zhu,et al.  Bioactive modification of poly(ethylene glycol) hydrogels for tissue engineering. , 2010, Biomaterials.

[44]  Francesco M Veronese,et al.  PEGylation, successful approach to drug delivery. , 2005, Drug discovery today.

[45]  J A Buckwalter,et al.  Aging and degeneration of the human intervertebral disc. , 1995, Spine.

[46]  A. Freemont,et al.  Open Access Research Article Transcriptional Profiling of Bovine Intervertebral Disc Cells: Implications for Identification of Normal and Degenerate Human Intervertebral Disc Cell Phenotypes , 2022 .

[47]  L. Setton,et al.  Matrix protein gene expression in intervertebral disc cells subjected to altered osmolarity. , 2002, Biochemical and biophysical research communications.

[48]  L. Liotta,et al.  Isolation and characterization of type IV procollagen, laminin, and heparan sulfate proteoglycan from the EHS sarcoma. , 1982, Biochemistry.

[49]  D. Seliktar,et al.  Protein-polymer conjugates for forming photopolymerizable biomimetic hydrogels for tissue engineering. , 2007, Biomaterials.

[50]  H. Gruber,et al.  Human disc cells in monolayer vs 3D culture: cell shape, division and matrix formation , 2000, BMC musculoskeletal disorders.

[51]  C. Gilchrist,et al.  Integrin‐mediated interactions with extracellular matrix proteins for nucleus pulposus cells of the human intervertebral disc , 2013, Journal of orthopaedic research : official publication of the Orthopaedic Research Society.

[52]  Damien M O'Halloran,et al.  Tissue-engineering approach to regenerating the intervertebral disc. , 2007, Tissue engineering.

[53]  K. Ando,et al.  Atelocollagen for culture of human nucleus pulposus cells forming nucleus pulposus-like tissue in vitro: influence on the proliferation and proteoglycan production of HNPSV-1 cells. , 2006, Biomaterials.

[54]  Farshid Guilak,et al.  Injectable laminin-functionalized hydrogel for nucleus pulposus regeneration. , 2013, Biomaterials.

[55]  A. Javed,et al.  Osteogenic differentiation of human mesenchymal stem cells synergistically enhanced by biomimetic peptide amphiphiles combined with conditioned medium. , 2011, Acta biomaterialia.

[56]  Kevin F. Spratt,et al.  Classification of Age-Related Changes in Lumbar Intervertebral Discs , 2002 .

[57]  Kytai Truong Nguyen,et al.  Photopolymerizable hydrogels for tissue engineering applications. , 2002, Biomaterials.

[58]  Laura M. Marquardt,et al.  Student award winner in the undergraduate's degree category for the Society for Biomaterials 35th Annual Meeting, Orlando, Florida, April 13-16, 2011. Neurite growth in PEG gels: effect of mechanical stiffness and laminin concentration. , 2011, Journal of biomedical materials research. Part A.

[59]  S Holm,et al.  Nutrition of the intervertebral disc: solute transport and metabolism. , 1981, Connective tissue research.

[60]  R. Scott,et al.  Characterization of poly(ethylene glycol) gels with added collagen for neural tissue engineering. , 2010, Journal of biomedical materials research. Part A.

[61]  Jiyoung M Dang,et al.  Temperature-responsive hydroxybutyl chitosan for the culture of mesenchymal stem cells and intervertebral disk cells. , 2006, Biomaterials.

[62]  V C Mow,et al.  Alterations in the mechanical behavior of the human lumbar nucleus pulposus with degeneration and aging , 1997, Journal of orthopaedic research : official publication of the Orthopaedic Research Society.

[63]  L. Setton,et al.  Integrin expression in cells of the intervertebral disc , 2004, Journal of anatomy.

[64]  C. Gilchrist,et al.  Extracellular Matrix Ligand and Stiffness Modulate Immature Nucleus Pulposus Cell-Cell Interactions , 2011, PloS one.

[65]  J. Taboas,et al.  Notochordal cell conditioned medium stimulates mesenchymal stem cell differentiation toward a young nucleus pulposus phenotype , 2010, Stem Cell Research & Therapy.

[66]  J A Buckwalter,et al.  Ultrastructure of the human intervertebral disc. I. Changes in notochordal cells with age. , 1982, Tissue & cell.

[67]  C. Gilchrist,et al.  Nucleus pulposus cell-matrix interactions with laminins. , 2011, European cells & materials.

[68]  S. A. Shirazi-Adl,et al.  Nutrient supply and intervertebral disc metabolism. , 2006, The Journal of bone and joint surgery. American volume.