title: Remineralization of demineralized bone matrix (DBM) via alternating solution immersion (ASI).
abstract: In order to achieve successful clinical outcomes, biomaterials used for bone grafts must possess a number of traits including biocompatibility and osteoconductivity. These materials must also demonstrate appropriate mechanical stability to withstand handling as well as support potentially significant stresses at the implant site. Synthetic and natural polymer scaffolds used for bone tissue engineering (BTE) often lack necessary mechanical properties. Our goal was to internally mineralize natural collagenous matrix, thereby increasing mechanical properties of the material to useful levels. Published methods for intrafibrillar collagen mineralization were applied to clinically relevant-sized constructs but did not successfully deposit mineral in the interior of the constructs. To address this limitation, we developed a new technique for the remineralization of demineralized bone matrix (DBM) based on alternating solution immersion, or ASI. Mineral was removed from equine bone specimens, leaving behind a demineralized bone matrix (DBM). This matrix provides a framework for the nucleation and growth of a replacement mineral phase. Plain film radiography and microcomputed tomography (microCT) indicated accumulation of mineral within the DBM, and mechanical testing (3 point bending and compression) revealed a significant increase in stiffness between the DBM and the remineralized bone matrix (RBM). We believe this remineralization process will be useful in the preparation of stiff and strong allografts for clinical application.
authors.affiliation: Department of Orthopaedic Surgery, University of California, Davis School of Medicine, USA. masoicher@ucdavis.edu
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: David P
authors.initials: DP
authors.lastname: Fyhrie
mesh_terms: D000818:Animals; D001857:Bone Matrix / Q000000981:diagnostic imaging / Q000187:drug effects / Q000378:metabolism / Q000502:physiology*; D001861:Bone Regeneration / Q000187:drug effects; D016025:Bone Transplantation; D002113:Calcification, Physiologic / Q000187:drug effects; D003094:Collagen / Q000378:metabolism; D019245:Compressive Strength / Q000187:drug effects; D060748:Fetuins / Q000494:pharmacology; D006736:Horses; D007101:Immersion; D012996:Solutions; D013718:Tensile Strength / Q000187:drug effects; D055114:X-Ray Microtomography
chemical_list: D060748:Fetuins; D012996:Solutions; D003094:Collagen
keywords: ASI; BTE; Bone graft; Collagen; DBM; HA; MC3; MVF; Matrix; Mineralization; RBM; SDS; Tissue engineering; alternating solution immersion; bone tissue engineering; demineralized bone matrix; hydroxyapatite; mineral volume fraction; remineralized bone matrix; sodium dodecyl sulfate; third metacarpal bone