Difference of adherence, proliferation and osteogenesis of mesenchymal stem cells cultured on different HA/ZrO2 composites / 中华创伤杂志(英文版)

ABSTRACT

<p><b>OBJECTIVE</b>To study the adherence, proliferation and osteogenesis of mesenchymal stem cells (MSCs) cultured on different HA/ZrO2 composites.</p><p><b>METHODS</b>The simplex and graded HA/ZrO2 compo-sites were prepared using dry-laid method. The surface topography of the composites was observed by scanning electron microscope (SEM). The MSCs were isolated from rabbits and cultured on experimental groups (simplex HA/ZrO2 composite, graded HA/ZrO2 composite, pure HA or pure ZrO2 coatings respectively) and control group (ordinary culture plate). Then, we observed the adherence, proliferation and osteogenesis of the MSCs, detected the cellular alkaline phosphatase (ALP) activities, extracted total RNA and detected the mRNA expression of collagen I, osteocalcin and osteopontin using the reverse transcription and polymerase chain reaction (RT-PCR) method.</p><p><b>RESULTS</b>The SEM images confirmed that the surface of the simplex HA/ZrO2 composite was coverd by discon-tiguous HA layer with clear visualization of the partial ZrO2 matrix, while the surface of the graded HA/ZrO2 composite was fairly rough with porosity. X-ray diffraction showed that after high temperature sintering, the ZrO2 phase still remained, while the HA phase was transformed to beta-Ca3(PO4)2 , alpha-Ca3(PO4)2 and CaZrO3 phases on the surface of both composites. Cell culture indicated that the HA/ZrO2 composites supported cell attachment. Neither ALP expression nor mRNA expression of collagen I, osteocalcin or osteopontin from RT-PCR results showed significant deviation among four groups.</p><p><b>CONCLUSION</b>Among these four composites, the graded HA/ZrO2 composite promotes the MSCs proliferation and the osteogenic differentiation to a certain extent.</p>