Synthesis and characterization of photocrosslinkable gelatin and silk fibroin interpenetrating polymer network hydrogels.

To effectively repair or replace damaged tissues, it is necessary to design scaffolds with tunable structural and biomechanical properties that closely mimic the host tissue. In this paper, we describe a newly synthesized photocrosslinkable interpenetrating polymer network (IPN) hydrogel based on gelatin methacrylate (GelMA) and silk fibroin (SF) formed by sequential polymerization, which possesses tunable structural and biological properties. Experimental results revealed that IPNs, where both the GelMA and SF were independently crosslinked in interpenetrating networks, demonstrated a lower swelling ratio, higher compressive modulus and lower degradation rate as compared to the GelMA and semi-IPN hydrogels, where only GelMA was crosslinked. These differences were likely caused by a higher degree of overall crosslinking due to the presence of crystallized SF in the IPN hydrogels. NIH-3T3 fibroblasts readily attached to, spread and proliferated on the surface of IPN hydrogels, as demonstrated by F-actin staining and analysis of mitochondrial activity (MTT). In addition, photolithography combined with lyophilization techniques was used to fabricate three-dimensional micropatterned and porous microscaffolds from GelMA-SF IPN hydrogels, furthering their versatility for use in various microscale tissue engineering applications. Overall, this study introduces a class of photocrosslinkable, mechanically robust and tunable IPN hydrogels that could be useful for various tissue engineering and regenerative medicine applications.

[1]  A. Khademhosseini,et al.  Directed assembly of cell-laden microgels for fabrication of 3D tissue constructs , 2008, Proceedings of the National Academy of Sciences.

[2]  David L Kaplan,et al.  Functionalization of silk fibroin with NeutrAvidin and biotin. , 2011, Macromolecular bioscience.

[3]  David L Kaplan,et al.  Sonication-induced gelation of silk fibroin for cell encapsulation. , 2008, Biomaterials.

[4]  Paul A. Janmey,et al.  Soft biological materials and their impact on cell function. , 2007, Soft matter.

[5]  Ali Khademhosseini,et al.  Micro- and nanoscale control of the cardiac stem cell niche for tissue fabrication. , 2009, Tissue engineering. Part B, Reviews.

[6]  Xinqiao Jia,et al.  Hybrid multicomponent hydrogels for tissue engineering. , 2009, Macromolecular bioscience.

[7]  Keiji Numata,et al.  Mechanism of enzymatic degradation of beta-sheet crystals. , 2010, Biomaterials.

[8]  Yunxiao Liu,et al.  Hydrogel based on interpenetrating polymer networks of dextran and gelatin for vascular tissue engineering. , 2009, Biomaterials.

[9]  A. Khademhosseini,et al.  Cell-adhesive and mechanically tunable glucose-based biodegradable hydrogels. , 2011, Acta biomaterialia.

[10]  J. Vacanti,et al.  Tissue engineering. , 1993, Science.

[11]  R. Krishnamurthy,et al.  Study on influence of porosity, pore size, spatial and topological distribution of pores on microhardness of as plasma sprayed ceramic coatings , 2007 .

[12]  J. Kopeček.  Hydrogel biomaterials: a smart future? , 2007, Biomaterials.

[13]  A. Khademhosseini,et al.  Hydrogels in Biology and Medicine: From Molecular Principles to Bionanotechnology , 2006 .

[14]  David L. Kaplan,et al.  Water‐Stable Silk Films with Reduced β‐Sheet Content , 2005 .

[15]  Kristi S Anseth,et al.  Photocrosslinking of gelatin macromers to synthesize porous hydrogels that promote valvular interstitial cell function. , 2009, Tissue engineering. Part A.

[16]  A. Ahluwalia,et al.  Genipin-crosslinked chitosan/gelatin blends for biomedical applications , 2008, Journal of materials science. Materials in medicine.

[17]  Y. Ikada,et al.  Cross-linking of gelatin with carbodiimides. , 1996, Tissue engineering.

[18]  Biman B Mandal,et al.  Silk fibroin/gelatin multilayered films as a model system for controlled drug release. , 2009, European journal of pharmaceutical sciences : official journal of the European Federation for Pharmaceutical Sciences.

[19]  J. Vacanti,et al.  Tissue engineering : Frontiers in biotechnology , 1993 .

[20]  A. Metters,et al.  Synthetic matrix metalloproteinase-sensitive hydrogels for the conduction of tissue regeneration: Engineering cell-invasion characteristics , 2003, Proceedings of the National Academy of Sciences of the United States of America.

[21]  X Wang,et al.  Preparation of aligned porous gelatin scaffolds by unidirectional freeze-drying method. , 2010, Acta biomaterialia.

[22]  G. Vunjak‐Novakovic,et al.  Cartilage-like tissue engineering using silk scaffolds and mesenchymal stem cells. , 2006, Tissue engineering.

[23]  David L Kaplan,et al.  Porous 3-D scaffolds from regenerated silk fibroin. , 2004, Biomacromolecules.

[24]  Wei Liu,et al.  Development and evaluation of silk fibroin-based nerve grafts used for peripheral nerve regeneration. , 2007, Biomaterials.

[25]  A. Mathur,et al.  Structural and mechanical characteristics of silk fibroin and chitosan blend scaffolds for tissue regeneration. , 2005, Journal of biomedical materials research. Part A.

[26]  David L Kaplan,et al.  Silk-based biomaterials. , 2003, Biomaterials.

[27]  R. Spontak,et al.  Swelling behavior and morphological evolution of mixed gelatin/silk fibroin hydrogels. , 2005, Biomacromolecules.

[28]  Farshid Guilak,et al.  A biomimetic three-dimensional woven composite scaffold for functional tissue engineering of cartilage. , 2007, Nature materials.

[29]  Ali Khademhosseini,et al.  Microengineered hydrogels for tissue engineering. , 2007, Biomaterials.

[30]  G. Vunjak‐Novakovic,et al.  Stem cell-based tissue engineering with silk biomaterials. , 2006, Biomaterials.

[31]  Biman B Mandal,et al.  Silk fibroin/polyacrylamide semi-interpenetrating network hydrogels for controlled drug release. , 2009, Biomaterials.

[32]  Ali Khademhosseini,et al.  Directed 3D cell alignment and elongation in microengineered hydrogels. , 2010, Biomaterials.

[33]  R. Spontak,et al.  Effect of beta-sheet crystals on the thermal and rheological behavior of protein-based hydrogels derived from gelatin and silk fibroin. , 2005, Macromolecular bioscience.

[34]  A. Bigi,et al.  Mechanical and thermal properties of gelatin films at different degrees of glutaraldehyde crosslinking. , 2001, Biomaterials.

[35]  A. Khademhosseini,et al.  Cell-laden microengineered gelatin methacrylate hydrogels. , 2010, Biomaterials.

[36]  T. Nicolai,et al.  Structure and gelation mechanism of silk hydrogels. , 2010, Physical chemistry chemical physics : PCCP.

[37]  Ali Khademhosseini,et al.  Progress in tissue engineering. , 2009, Scientific American.

[38]  David L Kaplan,et al.  Vortex-induced injectable silk fibroin hydrogels. , 2009, Biophysical journal.

[39]  D. Mooney,et al.  Hydrogels for tissue engineering. , 2001, Chemical reviews.

[40]  R. Spontak,et al.  Mixed protein blends composed of gelatin and Bombyx mori silk fibroin: effects of solvent-induced crystallization and composition. , 2006, Biomacromolecules.

[41]  A. Hoffman.  Hydrogels for Biomedical Applications , 2001, Advanced drug delivery reviews.

[42]  Jacqueline T Johanas,et al.  Dynamic culture conditions to generate silk-based tissue-engineered vascular grafts. , 2009, Biomaterials.

[43]  David L Kaplan,et al.  Silk fibroin microtubes for blood vessel engineering. , 2007, Biomaterials.

[44]  Chun-Hsu Yao,et al.  An in vivo evaluation of a biodegradable genipin-cross-linked gelatin peripheral nerve guide conduit material. , 2005, Biomaterials.

[45]  D. Kaplan,et al.  Electrospun silk biomaterial scaffolds for regenerative medicine. , 2009, Advanced drug delivery reviews.

[46]  Andrew Gouldstone,et al.  Mechanically strong double network photocrosslinked hydrogels from N,N-dimethylacrylamide and glycidyl methacrylated hyaluronan. , 2008, Biomaterials.

[47]  Ali Khademhosseini,et al.  Modified Gellan Gum hydrogels with tunable physical and mechanical properties. , 2010, Biomaterials.

[48]  M Cornelissen,et al.  Structural and rheological properties of methacrylamide modified gelatin hydrogels. , 2000, Biomacromolecules.

[49]  Jason A Burdick,et al.  Review: photopolymerizable and degradable biomaterials for tissue engineering applications. , 2007, Tissue engineering.

[50]  Liu Yaxiong,et al.  Fabrication and characterization of chitosan/gelatin porous scaffolds with predefined internal microstructures , 2007 .

[51]  Ali Khademhosseini,et al.  Mechanically robust and bioadhesive collagen and photocrosslinkable hyaluronic acid semi-interpenetrating networks. , 2009, Tissue engineering. Part A.

[52]  Q. Feng,et al.  Preparation of 3-D regenerated fibroin scaffolds with freeze drying method and freeze drying/foaming technique , 2006, Journal of materials science. Materials in medicine.

[53]  Christine E Schmidt,et al.  Photopatterned collagen-hyaluronic acid interpenetrating polymer network hydrogels. , 2009, Acta biomaterialia.

[54]  Farshid Guilak,et al.  Advanced tools for tissue engineering: scaffolds, bioreactors, and signaling. , 2006, Tissue engineering.

[55]  A. Khademhosseini,et al.  Modular Tissue Engineering: Engineering Biological Tissues from the Bottom Up. , 2009, Soft matter.

[56]  Mingzhong Li,et al.  Enzymatic degradation behavior of porous silk fibroin sheets. , 2003, Biomaterials.