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21	Osseointegration of Temporary Anchorage Devices Using Recombinant Human Bone Morphogenetic Protein-2 Cruz, Erin E 01 May 2010 (has links) (PDF) Over the past 5 years, the use of titanium implants as temporary anchorage devices (TADs) has become an important tool in clinical orthodontic practices. The use of TADs have provided orthodontists a way of moving teeth against fixed objects rather than against the surrounding teeth, which tend to counteract desired motion. At present, viable attachment of TADs involves direct insertion through gingival tissue and piercing of the bone. Surface modifications such as sandblasted and acid-etched treatment or bone morphogenetic protein surface treatment, however, can be applied to the TADs to promote enhanced osseointegration, thereby allowing the TADs to serve as stable anchors while avoiding bone puncture. In this study, a comparison was made between sandblasted/acid-etched TADs and sandblasted/acid-etched/recombinant human bone morphogenetic protein-2 (rhBMP-2) treated TADs to determine whether rhBMP-2 promotes enhanced osseointegration. A total of 10 rats (4 controls and 6 treated with rhBMP-2) were used in the study, with 1 TAD placed on the skull of each rat. At the end of 6 weeks, the animals were euthanized by carbon dioxide asphyxiation, and bone blocks, each containing a TAD, were prepared for histological examination and biomechanical characterization. The results of this study showed that TADs treated with rhBMP-2 had greater bone formation at the bone-implant interface and an increase in total implant stability. osseointegration temporary anchorage device sandblasted and acid etched titanium Orthodontics and Orthodontology
22	Reduced Burst Release of Bioactive rhBMP-2 from a Three-phase Composite Scaffold Grant, David William 31 December 2010 (has links) Recombinant human bone morphogenic proteins (rhBMPs) are extensively studied and employed clinically for treatment of various bone defects. Current clinical delivery vehicles suffer wasteful burst releases that mandate supra-physiological dosing driving concerns over safety and cost. It was therefore investigated whether a unique drug delivery vehicle sequestered within a composite scaffold could lower the burst release of rhBMP-2. PLGA-calcium phosphate tri-phasic composite scaffolds delivered model protein BSA with burst release of ~13% and sustained kinetics of 0.5-1.5% BSA/day up to 45 days. rhBMP-2 was delivered with zero burst release however at much lower levels, totaling 0.09% to 0.9 % release over 10 days, but had up to 6.3-fold greater bioactivity than fresh rhBMP-2 (p<0.05). In conclusion, the three-phase composite scaffold can deliver bioactive proteins with a reduced burst release and sustained secondary kinetics. Drug delivery Bone Bone morphogenic protein BMP BMP-2 rhBMP-2 bone graft tissue engineering scaffold bone tissue engineering regenerative medicine osteoinduction osteoconduction osteogenesis generative surgery autoraft replacement synthetic autograft replacement morphogenic bioactivity assay protein release kinetics bovine serum albumin model protein biomaterials biomaterial surface analysis scanning electron microscope application accelerating voltage application burst release sustained kinetics sustained delivery composite scaffold three phase scaffold PLGA calcium phosphate mineral-polymer composite sterilization BMP sterilization long-term storage BMP storage 0541
23	Reduced Burst Release of Bioactive rhBMP-2 from a Three-phase Composite Scaffold Grant, David William 31 December 2010 (has links) Recombinant human bone morphogenic proteins (rhBMPs) are extensively studied and employed clinically for treatment of various bone defects. Current clinical delivery vehicles suffer wasteful burst releases that mandate supra-physiological dosing driving concerns over safety and cost. It was therefore investigated whether a unique drug delivery vehicle sequestered within a composite scaffold could lower the burst release of rhBMP-2. PLGA-calcium phosphate tri-phasic composite scaffolds delivered model protein BSA with burst release of ~13% and sustained kinetics of 0.5-1.5% BSA/day up to 45 days. rhBMP-2 was delivered with zero burst release however at much lower levels, totaling 0.09% to 0.9 % release over 10 days, but had up to 6.3-fold greater bioactivity than fresh rhBMP-2 (p<0.05). In conclusion, the three-phase composite scaffold can deliver bioactive proteins with a reduced burst release and sustained secondary kinetics. Drug delivery Bone Bone morphogenic protein BMP BMP-2 rhBMP-2 bone graft tissue engineering scaffold bone tissue engineering regenerative medicine osteoinduction osteoconduction osteogenesis generative surgery autoraft replacement synthetic autograft replacement morphogenic bioactivity assay protein release kinetics bovine serum albumin model protein biomaterials biomaterial surface analysis scanning electron microscope application accelerating voltage application burst release sustained kinetics sustained delivery composite scaffold three phase scaffold PLGA calcium phosphate mineral-polymer composite sterilization BMP sterilization long-term storage BMP storage 0541

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