Platelet-rich plasma, rhOP-1 (rhBMP-7) and frozen rib allograft for the reconstruction of bony mandibular defects in sheep. A pilot experimental study.
ABSTRACT A 6 cm bony defect in the mandible of 15 sheep, 8 years old, was reconstructed using variously allograft of frozen rib, rhOP-1 (rh BMP-7), platelet-rich plasma (PRP), and a combination of frozen rib allograft and rhOP-1. The histological, histomorphometric, immunohistochemical and radiographic features of reconstruction were analysed. The animals were euthanised at 2 months postoperatively. In the control and PRP groups, no bone formation was detected. The sheep receiving rhOP-1 showed some and those receiving both rhOP-1 and allograft showed most new bone formation; in both groups this was through endochondral and also fibrous ossification. The combination of bone allograft with growth factors demonstrated osteoconductive as well as osteoinductive properties, and is appealing in the management of problem fractures.
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ABSTRACT: Upon activation, platelets secrete an array of growth factors that contribute to bone regeneration. Combining platelet rich plasma (PRP) with bone graft substitutes has the potential to reduce or replace the reliance on autograft. Lack of standardisation and improper use may contribute to the conflicting outcomes reported within both pre-clinical and clinical investigations using PRP. This study investigates the effect of PRP dose for bone augmentation. Eighty critical size defects were created in the cancellous bone of the medial proximal tibia and distal femur of 20 five year old female sheep. The defects were treated with three doses of an autologous thrombin activated PRP combined with a biphasic calcium phosphate (BCP) or autograft and empty defects. Radiography, micro-computed tomography, histology, histomorphometry fluorochrome bone labels were examined at 4 weeks. The empty defects did not spontaneously heal. The highest dose of PRP treatment had a significantly greater micro-CT BV/TV compared to the BCP alone (PRP: 30.6±1.8%; BCP: 24.5±0.1%). All doses of PRP treatment were significantly greater than the BCP alone for histomorphometric new bone area (PRP: 14.5±1.3%; BCP: 9.7±1.5%) and bone ingrowth depth (PRP: 2288±210µm; BCP:1151±268µm). From week two onwards, PRP had a significant effect on the weekly bone ingrowth over BCP, however, autograft had the highest amount of weekly fluorescent bone labelling. PRP induces new bone formation with a dose dependant response at four weeks when used with a biphasic calcium phosphate in sheep.Tissue Engineering Part A 03/2014; DOI:10.1089/ten.TEA.2013.0737 · 4.64 Impact Factor
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ABSTRACT: The aim of the present study was to compare the potential for cartilage repair of fresh amniotic membrane (AM), cryopreserved AM and cryopreserved AM previously cultured with bone marrow mesenchymal stem cells (BM-MSCs) in an in vivo sheep animal model.Current Stem Cell Research & Therapy 07/2014; DOI:10.2174/1574888X09666140710120012 · 2.86 Impact Factor
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ABSTRACT: Gradual bone lengthening using distraction osteogenesis principles is the gold standard for the treatment of hypoplastic facial bones. However, the long treatment time is a major disadvantage of the lengthening procedures. The aim of this study is to review the current literature and summarize the cellular and molecular events occurring during membranous craniofacial distraction osteogenesis. Mechanical stimulation by distraction induces biological responses of skeletal regeneration that is accomplished by a cascade of biological processes that may include differentiation of pluripotential tissue, angiogenesis, osteogenesis, mineralization, and remodeling. There are complex interactions between bone-forming osteoblasts and other cells present within the bone microenvironment, particularly vascular endothelial cells that may be pivotal members of a complex interactive communication network in bone. Studies have implicated number of cytokines that are intimately involved in the regulation of bone synthesis and turnover. The gene regulation of numerous cytokines (transforming growth factor-β, bone morphogenetic proteins, insulin-like growth factor-1, and fibroblast growth factor-2) and extracellular matrix proteins (osteonectin, osteopontin) during distraction osteogenesis has been best characterized and discussed. Understanding the biomolecular mechanisms that mediate membranous distraction osteogenesis may guide the development of targeted strategies designed to improve distraction osteogenesis and accelerate bone regeneration that may lead to shorten the treatment duration.01/2014; 2(1):e98. DOI:10.1097/GOX.0000000000000043