Vitamin-D Binding Protein Does Not Enhance Healing in Rat Bone Defects: A Pilot Study

Abstract

Vitamin D-binding protein (DBP) has an anabolic effect on the skeleton and reportedly enhances bone ingrowth. We used an in vivo critical bone defect model to determine whether local administration of DBP promotes bone defect healing. We created a 5-mm segmental bone defect in the radial shaft in a rat model. Forty-eight rats were assigned to eight groups: local application of 1 microg, 5 microg, 10 microg, or 50 microg DBP (DBP-1, DBP-5, DBP-10, DBP-50), autogenous bone marrow mononuclear cells with or without 10 microg DBP (BM-DBP-10, BM), 80 microg BMP-2 delivered in gelatin sponge (BMP-2), and the sham operated group. Radiographic evaluation, histological stains, and epifluorescence microscopy were performed. Grossly, all bone gaps of the BMP-2 group were solidly bridged by callus, while all those in the sham operated group remained unhealed by 9 weeks. Only one specimen of the BM-DBP-10 and DBP-50 groups and three specimens of the BM group were solidly healed; pseudarthroses occurred in all of the other specimens. Histological study and radiographs of the specimens showed similar results. We did not observe the enhanced bone healing reported in a previous study.

Behind the scenes of vitamin D binding protein: More than vitamin D binding

“…Administration of a synthetic peptide fragment (consisting of 14 amino acids) derived from the human amino acid sequence at the site of glycosylation in the third domain of native DBP, to newborn rats (0.4 ng/g body weight) resulted in osteoinduction of the marrow cavity and osteogenesis of surrounding cortical and metaphyseal bone [116]. Those results could not be confirmed in an in vivo critical bone defect model, investigating the bone healing capacity of DBP [117]. However this study had several limitations.…”

Overexpression of Insulin-Like Growth Factor 1 Enhanced the Osteogenic Capability of Aging Bone Marrow Mesenchymal Stem Cells

“…Bone graft materials are often required for the treatment of large bone defects 40, 41. Producing appropriate bioactive bone graft materials for bone regeneration is a crucial issue in orthopedics.…”

Methodological Consideration of Various Intraosseous and Heterotopic Bone Grafts Implantation in Animal Models

“…Recent development in tissue regeneration provided biomaterials for slow release of proteins over a period of time, thus giving cells continuous stimuli to differentiate into desired cells [60,65,66,68,70,73,75,76,78,92,[98][99][100]109,[116][117][118][119][120][121]. The level of gene expression in the surrounding tissue to regenerate bone can be enhanced by delivery of plasmid DNA using hydrogel microspheres, more than plasmid DNA solution.…”

“…The level of gene expression in the surrounding tissue to regenerate bone can be enhanced by delivery of plasmid DNA using hydrogel microspheres, more than plasmid DNA solution. BMP 2 -incorporated gelatin/ β-TCP scaffolds lead to significantly increased osteogenesis compared to the chem- ical induced osteogenesis in specimens [60,65,66,68,70,75,76,78,92,[98][99][100]109,[116][117][118][119][120][121]. In previous studies, various groups showed a continuous release of BMP2 in vitro and in vivo [65,66,68,70,73,75,76,92,[98][99][100]109,[119][120][121].…”