含二氧化矽材質常應用於骨組織工程，骨髓常因而與之接觸。臨床上，輻射治療會抑制紅血球分化，而先前 的研究發現二氧化矽顆粒可以刺激紅血球分化，但輻射照射時二氧化矽的生物效應則尚不清楚。本研究選取單核 球與紅白血球細胞株(HEL-92 cell line)的共同培養系統，探討二氧化矽對紅血球生成之效應；實驗上，利用MTT 法分析二氧化矽顆粒對單核球的細胞毒性，取安全劑量的二氧化矽顆粒探討紅血球生成的生物效應。實驗分成四 組，包括對照組、輻射處理組、二氧化矽處理組或輻射合併二氧化矽處理組，再以流式細胞儀分析血型糖蛋白A 的表現與細胞活性氧化物的生成。 在細胞培養的實驗中發現，輻射會抑制紅血球分化，在無毒性的濃度下，二氧化矽會增加紅血球分化。以流 式細胞儀分析顯示輻射會抑制血型糖蛋白A 的表現，而此生物效應會被二氧化矽顆粒所抑制。本研究結果顯示， 二氧化矽顆粒可能是藉由增加細胞中血型糖蛋白A 的表現提升輻射防護之作用。

Silica containing materials are commonly applied in bone tissue engineering and thereby bone marrow cells may contact with silica. Clinically, radiotherapy has been found able to inhibit erythrogenesis. In previous study, we found that silica particles can stimulate bone marrow to differentiate into erythrocytes; however, the biological effect of silicate remains unclear while ionizing radiation is applied. In this study, monocytes and erythroleukaemic cell line (HEL-92 cell line) were cocultured to evaluate the effect of silica particles on erythrogenesis. The toxicity of silica particles on monocytes was evaluted by MTT assay. Safe dose of silica particles were added into the culture medium to investigate the erythrogenesis. Four groups including the control, radiation treatment (5 Gy), silica treatment and a combinative treatment of radiation and silica were divided in the experiment. Analysis of the expression of glycophorin-A and the production of reactive oxygen species (ROS) were then carried out. In cells culture, the results indicated that radiation can inhibit the differentiation of erythrocytes, and the differentiation of erythrocytes was increased with the non-toxic concentration of silica particles. In flow cytometry assay, the glycophorin-A expression and the production of ROS were inhibited by radiation, whereas the effects were inhibited by the conditioned medium pretreated with silica. The results conclud that silica particles exert a radioprotective effect, which is probably via increasing the level of glycophorin-A expression within cells.