DOI:10.1111/j.1532-950X.2013.12123.x Objective: To describe a surgical technique using a regenerative approach and internal fixation for immediate reconstruction of critical size bone defects after segmental mandibulectomy in dogs. Study Design: Prospective case series. Animals: Dogs (n 4) that had reconstruction after segmental mandibulectomy for treatment of malignant or benign tumors. Methods: Using a combination of extraoral and intraoral approaches, a locking titanium plate was contoured to match the native mandible. After segmental mandibulectomy, the plate was secured and a compression resistant matrix (CRM) infused with rhBMP‐2, implanted in the defect. The implant was then covered with a soft tissue envelope followed by intraoral and extraoral closure. Results: All dogs that had mandibular reconstruction healed with intact gingival covering over the mandibular defect and had immediate return to normal function and occlusion. Mineralized tissue formation was observed clinically within 2 weeks and

While testing regenerative medicine strategies, the use of animal models that match the research questions and that are related to clinical translation is crucial. During the initial stage of evaluating new strategies for bone repair, the main goal is to state whether the strategies efficiently induce the formation of new bone tissue at an orthotopic site. Here, we present a subperiosteal model in rat calvaria that allow the evaluation of a broad range of approaches including bone augmentation, replacement and regeneration. The model is a fast to perform, minimally invasive, and has clearly defined control groups. The procedure enables to evaluate the outcomes quantitatively using micro-computed tomography and qualitatively by histology and immunohistochemistry. We established this new model, using bone morphogenetic protein-2 as an osteoinductive factor and hyaluronic acid hydrogel as injectable biomaterial. We showed that this subperiosteal cranial model offers a minimally invasive and promising solution for a rapid initial evaluation of injectables for bone repair. We believe that this approach could be a powerful platform for orthopedic research and regenerative medicine.

Recent progress in human embryonic and adult stem cell research is a cause for much enthusiasm in bone and joint surgery. Stem cells have therapeutic potential in the realm of orthopaedic surgery because of their capacity to self-renew and differentiate into various types of mature cells and tissues, including bone. Because nonunions re-main a clinically important problem, there is interest in the use of cell-based strategies to augment fracture repair. Such strategies are being investigated with variations in the model systems, sources of stem cells, and methods for the application and enhancement of osseous healing, including genetic modifications and tissue-engineering. This review highlights the recent progress in the utilization of stem cells and cell-based gene therapy in promoting fracture-healing and its potential utility in the clinical setting. New Strategies in the Treatment of Nonunions lthough new technologies and advances in ortho-paedic surgery have substantially enhanced fracture-healing and surgical outcomes, there is a subset of fractures that continue to be deficient in bone repair and culminate in nonunion. Four elements are integral to bone repair: an osteoconductive matrix, osteoinductive signals, os-

We report a facile approach to preparing laponite (LAP) bioceramics via sintering LAP powder compacts for bone tissue engineering applications. The sintering behavior and mechanical properties of LAP compacts under different temperatures, heating rates, and soaking times were investigated. We show that LAP bioceramic with a smooth and porous surface can be formed at 800uC with a heating rate of 5uC/h for 6 h under air. The formed LAP bioceramic was systematically characterized via different methods. Our results reveal that the LAP bioceramic possesses an excellent surface hydrophilicity and serum absorption capacity, and good cytocompatibility and hemocompatibility as demonstrated by resazurin reduction assay of rat mesenchymal stem cells (rMSCs) and hemolytic assay of pig red blood cells, respectively. The potential bone tissue engineering applicability of LAP bioceramic was explored by studying the surface mineralization behavior via soaking in simulated body fluid (SBF), as well as the surface cellular response of rMSCs. Our results suggest that LAP bioceramic is able to induce hydroxyapatite deposition on its surface when soaked in SBF and rMSCs can proliferate well on the LAP bioceramic surface. Most strikingly, alkaline phosphatase activity together with alizarin red staining results reveal that the produced LAP bioceramic is able to induce osteoblast differentiation of rMSCs in growth medium without any inducing factors. Finally, in vivo animal implantation, acute systemic toxicity test and hematoxylin and eosin (H&E)-staining data

The main objective of periodontal treatment is not only to relieve symptoms but also to regenerate the destroyed tissues. Many methods have been in-troduced for regenerating damaged periodontal

A critical size bony defect (CSD) is defined as the smallest intra-osseous wound characterized by an absence of spontaneous healing, which would not heal by bone formation during the lifetime (Schmitz

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This work focuses on the development of a candidate material for temporary synthetic bone. The material is a particulate filled composite based on an unsaturated linear polyester. The components are mixed with a monomer that cross links the double bonds of the unsaturated polyester. Degradation occurs via hydrolytic degradation of backbone polymer's ester linkages. This strategy of prepolymer synthesis via condensation polymerization in the laboratory followed by cross linking the unsaturated prepolymer via radical polymerization at surgery offers design flexibility. The radical polymerization allows curing during surgery to facilitate reconstruction of various shaped bone defects. The laboratory synthesis of the prepolymer allows alterations of its composition and physical properties to effect desired properties in the resulting composite material. The effects of several composite material formulation recipes on

The effect of particle size on the osteointegration of injectable silicate-substituted calcium phosphate bone substitute materials

Animal fracture models have been extensively applied to preclinical research as a platform to identify and charac-terize normal and abnormal physiological processes and to develop specific maneuvers that alter the biology and biomechanics being examined. The choice of animal model employed in a study bears a direct relationship to the specific intervention being analyzed. The animal models employed should be described clearly, control-group data should be established, and reproducibility should be defined from experiment to experiment and from institution to institution so that quantitative and qualitative outcomes can be reliably compared and contrasted to other related studies. Background Information nimal fracture models have been extensively applied to preclinical research as a platform to identify and characterize normal and abnormal physiological pro-cesses and to develop specific maneuvers that alter the biology and biomechanics being examined. By facilitating the transla-tion of in vitro discovery into in vivo testing, animal fracture models allow researchers to establish strategies to further un-