RESUMO
Skeletal stem cell (SSC) growth on a novel porous HA/TCP scaffold has been investigated in vivo. The effect of porosity on osteogenic differentiation was assessed by comparing two groups of scaffolds with differing porosity but controlled pore size. Histology, microCT, scanning electron microscopy, and biochemical analysis were used to assess SSC proliferation and differentiation. The 45 pores per inch (ppi) scaffold demonstrated a greater increase in density than the 30 ppi scaffold following in vivo culture, and a reduction in dimensions of the pores and channels of the higher porosity scaffold was observed, indicating generation of new tissue within the pores. All scaffolds supported SSC proliferation but the higher scaffold porosity augmented osteogenic differentiation. ALP specific activity was enhanced on the 45 ppi scaffold compared to the 30 ppi scaffold. These studies demonstrate the importance of porosity in scaffold design and impact therein for tissue engineering application.
Assuntos
Diferenciação Celular/efeitos dos fármacos , Cerâmica/farmacologia , Músculo Esquelético/citologia , Células-Tronco/citologia , Alicerces Teciduais/química , Adulto , Animais , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Humanos , Masculino , Camundongos , Camundongos Nus , Microscopia Eletrônica de Varredura , Porosidade , Coloração e Rotulagem , Células-Tronco/efeitos dos fármacos , Células-Tronco/metabolismo , Microtomografia por Raio-XRESUMO
Electrically active ceramics are of interest as bone graft substitute materials. This study investigated the ferroelectric properties of hydroxyapatite-barium titanate (HABT) composites and the behaviour of osteoblast-like cells seeded on their surfaces. A piezoelectric coefficient (d(33)) of 57.8 pCN(-1) was observed in HABT discs prepared for cell culture. The attachment, proliferation, viability, morphology and metabolic activity of cells cultured on unpoled HABT were comparable to those observed on commercially available hydroxyapatite at all time points. No indication of the cytotoxicity of HABT was detected. At one day after seeding, cell attachment was modified on both the positive and negative surfaces of poled HABT. After longer incubations, all parameters observed were comparable on poled and unpoled ceramics. The results indicate that HABT ceramics are biocompatible in the short term in vitro and that further investigation of cell responses to these materials under mechanical load and at longer incubation times is warranted.