title: Mesenchymal stem cells-seeded bio-ceramic construct for bone regeneration in large critical-size bone defect in rabbit.
abstract: Bone marrow derived mesenchymal stem cells (BMSC) represent an attractive cell population for tissue engineering purpose. The objective of this study was to determine whether the addition of recombinant human bone morphogenetic protein (rhBMP-2) and insulin-like growth factor (IGF-1) to a silica-coated calcium hydroxyapatite (HASi) - rabbit bone marrow derived mesenchymal stem cell (rBMSC) construct promoted bone healing in a large segmental bone defect beyond standard critical -size radial defects (15mm) in rabbits. An extensively large 30mm long radial ostectomy was performed unilaterally in thirty rabbits divided equally in five groups. Defects were filled with a HASi scaffold only (group B); HASi scaffold seeded with rBMSC (group C); HASi scaffold seeded with rBMSC along with rhBMP-2 and IGF-1 in groups D and E respectively. The same number of rBMSC (five million cells) and concentration of growth factors rhBMP-2 (50µg) and IGF-1 (50µg) was again injected at the site of bone defect after 15 days of surgery in their respective groups. An empty defect served as the control group (group A). Radiographically, bone healing was evaluated at 7, 15, 30, 45, 60 and 90 days post implantation. Histological qualitative analysis with microCT (µ-CT), haematoxylin and eosin (H & E) and Masson's trichrome staining were performed 90 days after implantation. All rhBMP-2-added constructs induced the formation of well-differentiated mineralized woven bone surrounding the HASi scaffolds and bridging bone/implant interfaces as early as eight weeks after surgery. Bone regeneration appeared to develop earlier with the rhBMP-2 constructs than with the IGF-1 added construct. Constructs without any rhBMP-2 or IGF-1 showed osteoconductive properties limited to the bone junctions without bone ingrowths within the implantation site. In conclusion, the addition of rhBMP-2 to a HASi scaffold could promote bone generation in a large critical-size-defect.
authors.affiliation: Principal Scientist, Surgery Division, Indian Veterinary Research Institute, Izatnagar, 243122, Uttar-Pradesh, India.
authors.forename: Swapan Kumar
authors.initials: SK
authors.lastname: Maiti
authors.affiliation: Ph.D Scholars, Surgery Division, Indian Veterinary Research Institute, Izatnagar, 243122, Uttar-Pradesh, India.
authors.forename: Ajantha Ravindran
authors.initials: AR
authors.lastname: Ninu
authors.affiliation: Ph.D Scholars, Surgery Division, Indian Veterinary Research Institute, Izatnagar, 243122, Uttar-Pradesh, India.
authors.forename: Palakkara
authors.initials: P
authors.lastname: Sangeetha
authors.affiliation: Ph.D Scholars, Surgery Division, Indian Veterinary Research Institute, Izatnagar, 243122, Uttar-Pradesh, India.
authors.forename: Dayamon D
authors.initials: DD
authors.lastname: Mathew
authors.affiliation: Ph.D Scholars, Surgery Division, Indian Veterinary Research Institute, Izatnagar, 243122, Uttar-Pradesh, India.
authors.forename: Paramasivam
authors.initials: P
authors.lastname: Tamilmahan
authors.affiliation: Senior Research Fellow, Surgery Division, Indian Veterinary Research Institute, Izatnagar, 243122, Uttar-Pradesh, India.
authors.forename: Deepika
authors.initials: D
authors.lastname: Kritaniya
authors.affiliation: Principal Scientist, Surgery Division, Indian Veterinary Research Institute, Izatnagar, 243122, Uttar-Pradesh, India.
authors.forename: Naveen
authors.initials: N
authors.lastname: Kumar
authors.affiliation: Director, Institute of Neurophysiology, Universität zu Köln, Robert-Koch-Strasse 39, D-50931, Köln, Germany.
authors.forename: Jurgen
authors.initials: J
authors.lastname: Hescheler
keywords: Insulin like growth factor; Mesenchymal stem cells; Recombinant human bone morphogenetic protein; Silica-coated calcium