Fibrin-loaded porous poly(ethylene glycol) hydrogels as scaffold materials for vascularized tissue formation.

Vascular network formation within biomaterial scaffolds is essential for the generation of properly functioning engineered tissues. In this study, a method is described for generating composite hydrogels in which porous poly(ethylene glycol) (PEG) hydrogels serve as scaffolds for mechanical and structural support, and fibrin is loaded within the pores to induce vascularized tissue formation. Porous PEG hydrogels were generated by a salt leaching technique with 100-150-μm pore size and thrombin (Tb) preloaded within the scaffold. Fibrinogen (Fg) was loaded into pores with varying concentrations and polymerized into fibrin due to the presence of Tb, with loading efficiencies ranging from 79.9% to 82.4%. Fibrin was distributed throughout the entire porous hydrogels, lasted for greater than 20 days, and increased hydrogel mechanical stiffness. A rodent subcutaneous implant model was used to evaluate the influence of fibrin loading on in vivo response. At weeks 1, 2, and 3, all hydrogels had significant tissue invasion, but no difference in the depth of invasion was found with the Fg concentration. Hydrogels with fibrin loading induced more vascularization, with a significantly higher vascular density at 20 mg/mL (week 1) and 40 mg/mL (weeks 2 and 3) Fg concentration compared to hydrogels without fibrin. In conclusion, we have developed a composite hydrogel that supports rapid vascularized tissue ingrowth, and thus holds great potential for tissue engineering applications.

[1]  S. Lord,et al.  Molecular Mechanisms Affecting Fibrin Structure and Stability , 2011, Arteriosclerosis, thrombosis, and vascular biology.

[2]  A novel composite construct increases the vascularization potential of PEG hydrogels through the incorporation of large fibrin ribbons. , 2010, Journal of biomedical materials research. Part A.

[3]  Ming-Huei Cheng,et al.  The role of pore size on vascularization and tissue remodeling in PEG hydrogels. , 2011, Biomaterials.

[4]  Jan P Stegemann,et al.  Influence of thrombin concentration on the mechanical and morphological properties of cell-seeded fibrin hydrogels. , 2007, Acta biomaterialia.

[5]  S. Coughlin,et al.  Thrombin signalling and protease-activated receptors , 2000, Nature.

[6]  S. Coughlin.  Sol Sherry lecture in thrombosis: how thrombin 'talks' to cells: molecular mechanisms and roles in vivo. , 1998, Arteriosclerosis, thrombosis, and vascular biology.

[7]  C. Patrick,et al.  Three-Dimensional, Quantitative Analysis of Desmin and Smooth Muscle Alpha Actin Expression During Angiogenesis , 2004, Annals of Biomedical Engineering.

[8]  M. Mosesson.  Fibrinogen and fibrin structure and functions , 2005, Journal of thrombosis and haemostasis : JTH.

[9]  Ge Zhang,et al.  Multimodal release of transforming growth factor-β1 and the BB isoform of platelet derived growth factor from PEGylated fibrin gels. , 2010, Journal of controlled release : official journal of the Controlled Release Society.

[10]  J. Weisel,et al.  The mechanical properties of fibrin for basic scientists and clinicians. , 2004, Biophysical chemistry.

[11]  Lie Ma,et al.  Fabrication and physical and biological properties of fibrin gel derived from human plasma , 2008, Biomedical materials.

[12]  D. Sierra,et al.  Fibrin Sealant Adhesive Systems: A Review of Their Chemistry, Material Properties and Clinical Applications , 1993, Journal of biomaterials applications.

[13]  Michael J. Miller,et al.  Periosteum-Guided Prefabrication of Vascularized Bone of Clinical Shape and Volume , 2009, Plastic and reconstructive surgery.

[14]  J. Hubbell,et al.  Mechanical properties, proteolytic degradability and biological modifications affect angiogenic process extension into native and modified fibrin matrices in vitro. , 2005, Biomaterials.

[15]  K. Siebenlist,et al.  The Structure and Biological Features of Fibrinogen and Fibrin , 2001, Annals of the New York Academy of Sciences.

[16]  M. Hincke,et al.  Fibrin: a versatile scaffold for tissue engineering applications. , 2008, Tissue engineering. Part B, Reviews.

[17]  L. McIntire,et al.  Therapeutic neovascularization: contributions from bioengineering. , 2005, Tissue engineering.

[18]  Z. Kam,et al.  Engineering vessel-like networks within multicellular fibrin-based constructs. , 2011, Biomaterials.

[19]  Jia-cong Shen,et al.  A polylactide/fibrin gel composite scaffold for cartilage tissue engineering: fabrication and an in vitro evaluation , 2009, Journal of materials science. Materials in medicine.

[20]  Catalina Wong,et al.  Fibrin-based biomaterials to deliver human growth factors , 2003, Thrombosis and Haemostasis.

[21]  P. Janmey,et al.  Fibrin gels and their clinical and bioengineering applications , 2009, Journal of The Royal Society Interface.

[22]  S. Hollister.  Porous scaffold design for tissue engineering , 2005, Nature materials.

[23]  Antonios G Mikos,et al.  Uncultured marrow mononuclear cells delivered within fibrin glue hydrogels to porous scaffolds enhance bone regeneration within critical-sized rat cranial defects. , 2010, Tissue engineering. Part A.

[24]  Monica L Moya,et al.  Synthesis of multilayered alginate microcapsules for the sustained release of fibroblast growth factor-1. , 2010, Journal of biomedical materials research. Part A.

[25]  Dai Fukumura,et al.  Engineering vascularized tissue , 2005, Nature Biotechnology.

[26]  E. Brey,et al.  Endothelial cell-matrix interactions in neovascularization. , 2008, Tissue engineering. Part B, Reviews.

[27]  Jeffrey A. Hubbell,et al.  Biomaterials in Tissue Engineering , 1995, Bio/Technology.

[28]  E. Brey,et al.  Generation of porous poly(ethylene glycol) hydrogels by salt leaching. , 2010, Tissue engineering. Part C, Methods.

[29]  Antonios G Mikos,et al.  Biomimetic materials for tissue engineering. , 2003, Biomaterials.