Enzymatic Mineralization of Hydrogels for Bone Tissue Engineering by Incorporation of Alkaline Phosphatase

• Published in: Macromolecular bioscience Vol. 12; no. 8; pp. 1077 - 1089
• Main Authors: Douglas, Timothy E. L., Messersmith, Philip B., Chasan, Safak, Mikos, Antonios G., de Mulder, Eric L. W., Dickson, Glenn, Schaubroeck, David, Balcaen, Lieve, Vanhaecke, Frank, Dubruel, Peter, Jansen, John A., Leeuwenburgh, Sander C. G.
• Format: Journal Article
• Language: English
• Published: Weinheim WILEY-VCH Verlag 01.08.2012; WILEY‐VCH Verlag; Wiley-VCH
• Subjects: Alkaline Phosphatase - chemistry; Alkaline Phosphatase - metabolism; Applied sciences; Biocompatible Materials - chemistry; Biocompatible Materials - metabolism; Biological and medical sciences; biomaterials; biomineralization; Bone and Bones - chemistry; Calcification, Physiologic; Calcium Phosphates - chemistry; Collagen Type I - chemistry; composites; Elastic Modulus; enzymes; Exact sciences and technology; Fumarates - chemistry; Humans; Hydrogels; Materials Testing; Medical sciences; Microscopy, Electron, Scanning; Natural polymers; Organic polymers; Physicochemistry of polymers; Polyethylene Glycols - chemistry; Polymerization; Properties and characterization; Proteins; Solution and gel properties; Spectroscopy, Fourier Transform Infrared; Surgery (general aspects). Transplantations, organ and tissue grafts. Graft diseases; Technology. Biomaterials. Equipments; Tissue Engineering - methods; Tissue Scaffolds; X-Ray Diffraction; Alkaline phosphatase; Strengthening; Support; In situ; Phosphoric monoester hydrolases; Esterases; Ethylene oxide polymer; Colloidal gel; Collagen type I; Mineralization; Fumarate copolymer; Biomaterial; Framework; Release; Enzyme; Tissue engineering; Biomineralization; Mechanical properties; Calcium phosphate; Ethylene oxide copolymer; Experimental study; Protein; Biological activity; Ester copolymer; Hydrolases; Kinetics; Hydrogel; Osseous tissue; Immobilized enzyme; Comparative study
• ISSN: 1616-5187; 1616-5195; 1616-5195
• DOI: 10.1002/mabi.201100501

Alkaline phosphatase (ALP), an enzyme involved in mineralization of bone, is incorporated into three hydrogel biomaterials to induce their mineralization with calcium phosphate (CaP). These are collagen type I, a mussel‐protein‐inspired adhesive consisting of PEG substituted with catechol groups, cPEG, and the PEG/fumaric acid copolymer OPF. After incubation in Ca‐GP solution, FTIR, EDS, SEM, XRD, SAED, ICP‐OES, and von Kossa staining confirm CaP formation. The amount of mineral formed decreases in the order cPEG > collagen > OPF. The mineral:polymer ratio decreases in the order collagen > cPEG > OPF. Mineralization increases Young's modulus, most profoundly for cPEG. Such enzymatically mineralized hydrogel/CaP composites may find application as bone regeneration materials. Enzymatic mineralization of three hydrogel biomaterials with calcium phosphate (CaP) is achieved by functionalization with alkaline phosphatase (ALP). Characterization of the hydrogels collagen type I, cPEG, and OPF reveals different degrees of mineralization, suggesting the possibility of enhancing mineralization for bone tissue engineering by the choice of hydrogel.