title: Remineralized bone matrix as a scaffold for bone tissue engineering.
abstract: There is a need for improved biomaterials for use in treating non-healing bone defects. A number of natural and synthetic biomaterials have been used for the regeneration of bone tissue with mixed results. One approach is to modify native tissue via decellularization or other treatment for use as natural scaffolding for tissue repair. In this study, our goal was to improve on our previously published alternating solution immersion (ASI) method to fabricate a robust, biocompatible, and mechanically competent biomaterial from natural demineralized bone matrix (DBM). The improved method includes an antigen removal (AR) treatment step which improves mineralization and stiffness while removing unwanted proteins. The chemistry of the mineral in the remineralized bone matrix (RBM) was consistent with dicalcium phosphate dihydrate (brushite), a material used clinically in bone healing applications. Mass spectrometry identified proteins removed from the matrix with AR treatment to include α-2 HS-glycoprotein and osteopontin, noncollagenous proteins (NCPs) and known inhibitors of biomineralization. Additionally, the RBM supported the survival, proliferation, and differentiation of human mesenchymal stromal cells (MSCs) in vitro as well or better than other widely used biomaterials including DBM and PLG scaffolds. DNA content increased more than 10-fold on RBM compared to DBM and PLG; likewise, osteogenic gene expression was significantly increased after 1 and 2 weeks. We demonstrated that ASI remineralization has the capacity to fabricate mechanically stiff and biocompatible RBM, a suitable biomaterial for cell culture applications.
authors.affiliation: Department of Orthopaedic Surgery, School of Medicine, University of California, Davis, California; Biomedical Engineering Graduate Group, University of California, Davis, California.
authors.forename: Matthew A
authors.initials: MA
authors.lastname: Soicher
authors.forename: Blaine A
authors.initials: BA
authors.lastname: Christiansen
authors.forename: Susan M
authors.initials: SM
authors.lastname: Stover
authors.forename: J Kent
authors.initials: JK
authors.lastname: Leach
authors.forename: Clare E
authors.initials: CE
authors.lastname: Yellowley
authors.forename: Leigh G
authors.initials: LG
authors.lastname: Griffiths
authors.forename: David P
authors.initials: DP
authors.lastname: Fyhrie
mesh_terms: D000818:Animals; D000943:Antigens, Differentiation / Q000096:biosynthesis; D002454:Cell Differentiation; D002478:Cells, Cultured; D005109:Extracellular Matrix / Q000737:chemistry*; D005786:Gene Expression Regulation; D006736:Horses; D006801:Humans; D059630:Mesenchymal Stem Cells / Q000166:cytology / Q000378:metabolism*; D050279:Metacarpal Bones / Q000737:chemistry*; D010012:Osteogenesis; D023822:Tissue Engineering / Q000379:methods*; D054457:Tissue Scaffolds / Q000737:chemistry*
chemical_list: D000943:Antigens, Differentiation
keywords: MSCs; bone graft; brushite; collagen; matrix; mineralization