Low proliferation and high apoptosis of osteoblastic cells on hydrophobic surface are associated with defective Ras signaling

<b>Enhancing osteoblast-affinity of titanium scaffolds for bone engineering by use of ultraviolet light tr</b><b>eatment </b>

“…The combined use of a rough surface and UV treatment might be the reasonable solution to achieve both promoted differentiation of osteoblasts and a hydrophilic property. Scaffold materials suitable for bone engineering are required to possess the ability to attract cells to their surface because osteoblasts are anchorage-dependent cells that need an appropriate adhesion signaling to proliferate (4,6,23). UV treatment promotes cell attraction and adhesion through electrostatic mechanisms (15).…”

“…The UV treatment induces various physicochemical changes to the surface of titanium as follows: 1) removing accumulating carbon, 2) converting the hydrophilicity from hydrophobic to hydrophilic, and 3) converting the electrical charge from electro-negative to electropositive (2,3,17,19). These surface properties of UV-treated titanium are considered advantageous for osteoblast affinity (4,11,15). Furthermore, UV treatment can be applied to all titanium devices of any design surface topography.…”

Mechanisms by which the inhibition of specific intracellular signaling pathways increase osteoblast proliferation on apatite surfaces

“…Previously, we showed that adequate adhesion signaling is necessary for a cell to progress into cell cycle and that growth factordependent signaling alone cannot induce cell cycle progression on a hydrophobic surface where cell-adhesion signaling is weak [5]. Recently, we reported that proliferation and migration of osteoblasts were markedly improved after Rho-associated kinase (ROCK) inhibition on hydrophobic surfaces although the molecular mechanisms of ROCK in osteoblast proliferation are not known [6].…”

O bombardeamento da superfície de titânio com íons de argônio influencia a resposta biológica de pré-osteoblastos

“…A maior molhabilidade das superfícies tratadas também favoreceu a maior proliferação dos pré-osteblastos, o que estaria de acordo com Chang et al (2005) que observaram alto crescimento de osteoblastos MG-63 em superfícies hidrofílicas.…”

“…Os autores demonstraram que as superfícies hidrofóbicas prejudicaram a ativação de AKt e ERK, os quais são responsáveis pela progressão do ciclo celular, já que são necessárias para induzir a síntese de ciclina D, que por sua vez desencadeia a mudança da fase G1 para S promovendo a proliferação celular (CHANG et al, 2005).…”