<i>In vitro</i> and <i>in vivo</i> evaluation of bioglass microspheres incorporated brushite cement for bone regeneration

다국어 초록 (Multilingual Abstract)

<P><B>Abstract</B></P> <P>Bioglass-calcium phosphate cement (CPC) composite materials have recently received increased attention for bone regeneration purposes, owing to their improved properties in term of biocompatibility and bone ingrowths. In this study, an injectable bone substitute (IBS) system which utilizes bioglass microspheres incorporated into brushite based cement, was evaluated. The microspheres were synthesized with a simple and low sintering temperature process; there was no significant phase difference shown from the powder and good interactivity with cells was obtained. Furthermore, physical properties were optimized in microsphere incorporated brushite cement in order to investigate <I>in vitro</I> and <I>in vivo</I> performance. Accordingly, setting time and compressive strength were hardly altered until a microsphere content of 40% (v/v) was reached. The brushite (BR)/bioglass microsphere (BM) system showed excellent bioactivity to the <I>in-vitro</I> simulated body fluid test: dissolution ions from composite materials influenced apatite growth, countered acidic pH, and increased material degradation. In an <I>in-vitro</I> study with preosteoblasts (MC3T3-E1), BR/BM supported cell adhesion and proliferation, while cell differentiation experiments without osteogenic supplements, demonstrated that BR/BM induced osteogenic differentiation. A post-implantation study conducted in femoral defects showed higher materials degradation and bone formation in BR/BM than in BR. The faster dissolution of bioglass microspheres increased BR/BM composite resorption and hence facilitated bone tissue integration. Our findings suggest that bioglass microspheres incorporated in cement could potentially be used as an injectable bone substitute for bone regeneration applications.</P> <P><B>Highlights</B></P> <P> <UL> <LI> 45S5 bioglass microspheres were fabricated with sintering temperature of a 950 °C in order to incorporate into brushite cement. </LI> <LI> In the composite IBS system, the microspheres (40%) were well distributed and retained good handling properties for clinical application. </LI> <LI> Microspheres releasing ions actively guided cellular behaviour and supported for osteoblast differentiation </LI> <LI> The empty space produced by the degradation of microspheres from brushite prompted to neovascularisations and bone tissue integration. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>