RESUMO
The aim of this study was to evaluate the effects of an osteogenic medium supplemented with platelet-derived growth factor (PDGF) BB and osteogenic protein (OP) 1 on the proliferation and differentiation of mesenchymal stem cells (MSCs) in an anorganic bovine cancellous bone scaffold. At day 7, there was a statistically significant increase in the number of cells in the scaffolds in the group treated with the medium supplemented with both PDGF-BB and OP-1 when compared with the control groups. The highest alkaline phosphate levels, at 14 and 21 days, were recorded for the samples in medium supplemented with OP-1 alone reflecting osteogenic differentiation. The results commend OP-1, as well as PDGF-BB, for incorporation into porous mineral scaffolds for vertical ridge augmentation.
Assuntos
Indutores da Angiogênese/farmacologia , Matriz Óssea , Proteína Morfogenética Óssea 7/farmacologia , Células-Tronco Mesenquimais/efeitos dos fármacos , Proteínas Proto-Oncogênicas c-sis/farmacologia , Alicerces Teciduais , Fosfatase Alcalina/análise , Animais , Becaplermina , Matriz Óssea/química , Bovinos , Adesão Celular/efeitos dos fármacos , Contagem de Células , Técnicas de Cultura de Células , Diferenciação Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Meios de Cultura , DNA/análise , Feminino , Cabras , Microscopia Eletrônica de Varredura , Minerais/química , Osteogênese/efeitos dos fármacos , Porosidade , Compostos Radiofarmacêuticos , Proteínas Recombinantes , Medronato de Tecnécio Tc 99m , Fatores de Tempo , Engenharia Tecidual , Alicerces Teciduais/químicaRESUMO
While the infection rate of orthopedic implants is low, the required treatment, which can involve six weeks of antibiotic therapy and two additional surgical operations, is life threatening and expensive, and thus motivates the development of a one-stage re-implantation procedure. Polyelectrolyte multilayers incorporating gentamicin were fabricated using the layer-by-layer deposition process for use as a device coating to address an existing bone infection in a direct implant exchange operation. The films eluted about 70% of their payload in vitro during the first three days and subsequently continued to release drug for more than four additional weeks, reaching a total average release of over 550 microg/cm(2). The coatings were demonstrated to be bactericidal against Staphylococcus aureus, and degradation products were generally nontoxic towards MC3T3-E1 murine preosteoblasts. Film-coated titanium implants were compared to uncoated implants in an in vivo S. aureus bone infection model. After a direct exchange procedure, the antimicrobial-coated devices yielded bone homogenates with a significantly lower degree of infection than uncoated devices at both day four (p < 0.004) and day seven (p < 0.03). This study has demonstrated that a self-assembled ultrathin film coating is capable of effectively treating an experimental bone infection in vivo and lays the foundation for development of a multi-therapeutic film for optimized, synergistic treatment of pain, infection, and osteomyelitis.