title: In vitro and in vivo optimization of impaction allografting by demineralization and addition of rh-OP-1.
abstract: Impaction allografting is a bone tissue engineering technique currently used in lower limb reconstruction orthopedic surgery. Our hypothesis was that biological optimization can be achieved by demineralization and addition of osteogenic protein-1 (OP-1) to the allograft. The objective of our in vitro study was to evaluate human mesenchymal stem cell (MSC) proliferation (Alamar Blue assay, titrated thymidine assay, total DNA Hoechst 33258, and scanning electron microscopy) and osteogenic differentiation (alkaline phosphatase assay) in two types of impacted carrier, namely, demineralized bone matrix (DBM) and insoluble collagenous bone matrix (ICBM), with or without OP-1. The objective in vivo was to compare the osteogenic potential of impacted DBM with or without OP-1, with that of impacted fresh frozen allograft (FFA), again with or without OP-1. DBM + OP-1 optimized osteoinduction and significantly improved (p < 0.05) proliferation and differentiation in comparison to the majority of all other graft preparation in vitro. In addition, DBM + OP-1 was significantly superior, with regard to osteogenesis, compared to the impacted FFA alone (p < 0.001), FFA + OP-1 (p = 0.01) and DBM alone (p = 0.02) in vivo. We propose that partial demineralization and addition of OP-1 provides a good method for improving the osteoinductive properties of fresh allograft currently used in the impaction grafting technique.
authors.affiliation: Biomaterials and Biomimetics Group, King's College London, University of London, Guy's Hospital, London SE1 9RT, United Kingdom. etsiridis@doctors.org.uk
authors.forename: Eleftherios
authors.initials: E
authors.lastname: Tsiridis
authors.forename: Zubier
authors.initials: Z
authors.lastname: Ali
authors.forename: Amit
authors.initials: A
authors.lastname: Bhalla
authors.forename: Manolis
authors.initials: M
authors.lastname: Heliotis
authors.forename: Neelam
authors.initials: N
authors.lastname: Gurav
authors.forename: Sanjukta
authors.initials: S
authors.lastname: Deb
authors.forename: Lucy
authors.initials: L
authors.lastname: DiSilvio
mesh_terms: D000328:Adult; D000469:Alkaline Phosphatase / Q000378:metabolism; D000818:Animals; D018775:Bone Demineralization Technique; D001854:Bone Marrow Cells / Q000187:drug effects / Q000648:ultrastructure; D001857:Bone Matrix / Q000637:transplantation*; D055419:Bone Morphogenetic Protein 7; D019485:Bone Morphogenetic Proteins / Q000494:pharmacology*; D016025:Bone Transplantation / Q000295:instrumentation / Q000379:methods*; D002454:Cell Differentiation / Q000187:drug effects; D049109:Cell Proliferation / Q000187:drug effects; D002478:Cells, Cultured; D006801:Humans; D008297:Male; D059630:Mesenchymal Stem Cells / Q000187:drug effects / Q000201:enzymology / Q000648:ultrastructure; D010012:Osteogenesis / Q000187:drug effects / Q000502:physiology; D051381:Rats; D017208:Rats, Wistar; D023822:Tissue Engineering / Q000295:instrumentation / Q000379:methods*; D014184:Transplantation, Homologous
chemical_list: C525819:BMP7 protein, human; C525821:Bmp7 protein, rat; D055419:Bone Morphogenetic Protein 7; D019485:Bone Morphogenetic Proteins; D000469:Alkaline Phosphatase