Home About us Contact
|
Home About us Contact | ||
|
|
||
Osteoinductive Potential (osteoinductive + potential)
Selected AbstractsSubcutaneous-induced membranes have no osteoinductive effect on macroporous HA-TCP in vivoJOURNAL OF ORTHOPAEDIC RESEARCH, Issue 2 2009Sylvain Catros Abstract Induced Membranes Technique was first described to enhance bone reconstruction of large osseous defects. Previous in vitro studies established their osteoinductive potential, due to the presence of opteoblasts precursors and to high amounts of growth factors contained within. The purpose of this study was to test in vivo the osteoinductive properties of induced membranes on a macroporous HA-TCP in a nonosseous subcutaneous site. Subcutaneous-induced membranes were obtained in 21 rabbits; 1 month later, the membranes were filled with a biphasic calcium phosphate material composed of 75% hydroxyapatite (HA) and 25% ,-tricalcium phosphate associated or not with autograft. Histological and immunohistochemical studies were performed on membrane biopsies. Undecalcified and decalcified sections were qualitatively and quantitatively analyzed. 45Ca uptake was observed and quantified on the sections using microimager analysis. Dense vascularity was found in the induced membranes. New bone formation was detected in the HA-TCP,+,autograft samples and increased significantly from 3 to 6 months (p,<,0.05). No bone was detected in the biomaterial graft alone in the induced membranes at any time. This study showed that induced membranes placed in a nonosseous site have no osteoinductive properties on a macroporous biphasic calcium phosphate biomaterial. © 2008 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 27:155,161, 2009 [source] Relevance of Osteoinductive Biomaterials in Critical-Sized Orthotopic DefectJOURNAL OF ORTHOPAEDIC RESEARCH, Issue 5 2006Pamela Habibovic Abstract Several publications have shown the phenomenon of osteoinduction by biomaterials to be real. However, whether the ability of a biomaterial to initiate bone formation in ectopic implantation sites improves the performance of such osteoinductive biomaterial in clinically relevant orthotopic sites remains unclear. No studies have been published in which osteoinductive potential of a biomaterial is directly related to its performance orthotopically. In this study, we compared osteoinductive and nonosteoinductive biphasic calcium,phosphate (BCP) ceramics ectopically and in a clinically relevant critical-sized orthotopic defect in goats. The two materials, BCP1150 and BCP1300, had similar chemical compositions, crystallinities, and macrostructures, but their microstructures differed significantly. BCP1150, sintered at a lower temperature, had a large amount of micropores, small average crystal size, and hence a high specific surface area. In contrast, BCP1300, with few micropores, had a significantly lower specific surface area as compared to BCP1150. Twelve-week intramuscular implantation in goats (n,=,10) showed that bone was induced in all BCP1150 implants, while no signs of bone formation were found in any of the BCP1300 implants. After 12 weeks of implantation in a bilateral critical-sized iliac wing defect in the same goats, BCP1150 showed significantly more bone than BCP1300. In addition, the analysis of fluorochrome markers, which were administered to the animals 4, 6, and 8 weeks after implantation to follow the bone growth dynamics, showed an earlier start of bone formation in BCP1150 as compared to BCP1300. Significantly better performance of an osteoinductive ceramic in a critical-sized orthotopic defect in a large animal model in comparison to a nonosteoinductive ceramic suggests osteoinduction to be clinically relevant. Further improvement of material osteoinductive properties is thus a significant step forward in the search for alternatives for autologous bone graft. © 2006 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res [source] Functional and proteomic analysis of serum and cerebrospinal fluid derived from patients with traumatic brain injury: a pilot studyANZ JOURNAL OF SURGERY, Issue 7-8 2010Dieter Cadosch Abstract Background:, An enhanced fracture healing response has been reported in patients with traumatic brain injury (TBI). This has been attributed to circulating humoral factors that are thought to be proteins produced and released by the injured brain. However, these factors remain unknown. The aim of this study was to identify osteogenic factors in serum and cerebrospinal fluid (CSF) from TBI patients. This was carried out using in vitro proliferation assays with the human foetal osteoblastic 1.19 cell line (hFOB) combined with a novel proteomic approach. Methods:, Serum was collected from brain-injured (n = 12) and non-brain-injured (n = 9) patients with a comorbid femur shaft fracture. Similarly, CSF was obtained from TBI (n = 7) and non-TBI (n = 9) patients. The osteoinductive potential of these samples was determined by measuring the in vitro proliferation rate of hFOB cells. Highly osteogenic serum and CSF samples of TBI patients were chosen for protein analysis and were compared to those of non-brain-injured patients. A new hFOB cell-based method was used to enrich the proteins in these samples, which had a functional affinity for these osteoprogenitor cells. These enriched protein fractions were mapped using two-dimensional gel electrophoresis and protein imaging methods displaying serum and CSF proteins of brain-injured and control subjects that had an affinity for human osteoprogenitor cells. Results:, Serum and CSF derived from brain-injured patients demonstrated a greater osteoinductive potential (P < 0.05) than their non-brain-injured counterparts. Clear-cut differences in the pattern of proteins in two-dimensional gels were detected between TBI and control patients. Fourteen proteins were exclusively present in the serum of TBI patients, while other proteins were either up- or downregulated in samples collected from TBI patients (P < 0.05). Conclusion:, Osteoinductive factors are present in the serum and CSF of brain-injured patients. These may include one or more of those proteins identified as having an affinity for osteoprogenitor cells that are either exclusively present or up- or downregulated in the serum and CSF of brain-injured patients. [source] Bone Reformation and Implant Integration following Maxillary Sinus Membrane Elevation: An Experimental Study in PrimatesCLINICAL IMPLANT DENTISTRY AND RELATED RESEARCH, Issue 1 2006Vinicius C Palma DDS ABSTRACT Background:, Recent clinical studies have described maxillary sinus floor augmentation by simply elevating the maxillary sinus membrane without the use of adjunctive grafting materials. Purpose:, This experimental study aimed at comparing the histologic outcomes of sinus membrane elevation and simultaneous placement of implants with and without adjunctive autogenous bone grafts. The purpose was also to investigate the role played by the implant surface in osseointegration under such circumstances. Materials and Methods:, Four tufted capuchin primates had all upper premolars and the first molar extracted bilaterally. Four months later, the animals underwent maxillary sinus membrane elevation surgery using a replaceable bone window technique. The schneiderian membrane was kept elevated by insertion of two implants (turned and oxidized, Brånemark System®, Nobel Biocare AB, Göteborg, Sweden) in both sinuses. The right sinus was left with no additional treatment, whereas the left sinus was filled with autogenous bone graft. Implant stability was assessed through resonance frequency analysis (OsstellTM, Integration Diagnostics AB, Göteborg, Sweden) at installation and at sacrifice. The pattern of bone formation in the experimental sites and related to the different implant surfaces was investigated using fluorochromes. The animals were sacrificed 6 months after the maxillary sinus floor augmentation procedure for histology and histomorphometry (bone-implant contact, bone area in threads, and bone area in rectangle). Results:, The results showed no differences between membrane-elevated and grafted sites regarding implant stability, bone-implant contacts, and bone area within and outside implant threads. The oxidized implants exhibited improved integration compared with turned ones as higher values of bone-implant contact and bone area within threads were observed. Conclusions:, The amount of augmented bone tissue in the maxillary sinus after sinus membrane elevation with or without adjunctive autogenous bone grafts does not differ after 6 months of healing. New bone is frequently deposited in contact with the schneiderian membrane in coagulum-alone sites, indicating the osteoinductive potential of the membrane. Oxidized implants show a stronger bone tissue response than turned implants in sinus floor augmentation procedures. [source] The effect of enamel matrix proteins and deproteinized bovine bone mineral on heterotopic bone formationCLINICAL ORAL IMPLANTS RESEARCH, Issue 4 2006Nikolaos Donos Abstract Aim: To evaluate the osteoinductive potential of deproteinized bovine bone mineral (DBBM) and an enamel matrix derivative (EMD) in the muscle of rats. Material and methods: Sixteen rats were used in this study. The animals were divided in three groups. Group A: a pouch was created in one of the pectoralis profundis muscles of the thorax of the rats and DBBM particles (Bio-Oss®) were placed into the pouch. Healing: 60 days. Group B: a small pouch was created on both pectoralis profundis muscles at each side of the thorax midline. In one side, a mixture of EMD (Emdogain®) mixed with DBBM was placed into one of the pouches, whereas in the contralateral side of the thorax the pouch was implanted with DBBM mixed with the propylene glycol alginate (PGA , carrier for enamel matrix proteins of EMD). Healing: 60 days. Group C: the same procedure as group B, but with a healing period of 120 days. Qualitative histological analysis of the results was performed. Results: At 60 days, the histological appearance of the DBBM particles implanted alone was similar to that of the particles implanted together with EMD or PGA at both 60 and 120 days. The DBBM particles were encapsulated into a connective tissue stroma and an inflammatory infiltrate. At 120 days, the DBBM particles implanted together with EMD or PGA exhibited the presence of resorption lacunae in some cases. Intramuscular bone formation was not encountered in any group. Conclusion: The implantation of DBBM particles alone, combined with EMD or its carrier (PGA) failed to exhibit extraskeletal, bone-inductive properties. [source] | ||||||||||