探討奈米材料nanosponge在生物醫學上的應用

Abstract

奈米材料具有獨特的物理和化學特性非常適合發展生物醫學的應用。Nanosponge 是一種嶄新的材料，經由蝕刻氧化矽表面得到的奈米結構，可以呈現出粗糙或光滑的表面，也可以設計成所需的圖案，並且表面非常容易進行化學官能基修飾。這個表面特殊的奈米結構，在可見光波段有極低的反射率，也因為生物相容性好，亦可以當作細胞生長的平台。反射式顯微鏡是生物影像上經常使用的研究工具，我們假設nanosponge的高吸光率可以幫助降低背景反射並提高訊號和雜訊的比率。為了證明這個假設，我們比較了將傳統的0.17 mm蓋玻片或nanosponge墊在150 nm 奈米銀、6 μ聚本乙烯微米球甚至是170mm螢光奈米求底下，都能在nanosponge上得到比較集中的訊號以及比較強對比度的影像。除此之外，我們先證明了nanosponge的生物相容性是非常好的，更進一步想發展nanosponge在生物醫學方面的應用。根據實驗結果我們發現，nanosponge似乎能夠當作一個生物支持的平台，讓分泌性的胰島素瘤細胞持續穩定分泌胰島素。本研究證明了奈米蝕刻的nanosponge不論在光學或生物醫學上都非常具有發展潛力。

The unique physical and chemical properties presented by nanomaterials envision powerful applications in biomedicine. For instance, custom designed optical properties through nano-topography may provide revolutionary impact on bioimaging and medical diagnostics. Nanosponge is a novel nano-topographic oxidized silicon material that is capable of robust and versatile surface chemical modifications. Its characteristic surface nanostructure renders minimal optical reflection at the visible light spectrum, while the silicon nature of the material provides good support for cell growth and biocompatibility. Since reflection mode microscopy represents one of the most important research tools for direct visualization of life processes, we reasoned that the light absorbing nature of the nanosponge may help reduce background illumination resulting in improved signal to noise ratio during reflection mode imaging. To test this hypothesis, we compared reflection mode signals derived from standardized materials when padded on conventional cover glass or nanosponge. Our data suggest that reflection visualization of 150 nm silver nanoparticles, 6 μm polystyrene microspheres as well as fluorescence emission by 170 nm fluoresecent microspheres, result in an increased optical density and contrast of their signals over a reduced general background. In addition, according to our characterization on the in vitro biocompatibility of the nanosponge, we were curious about the possible applications of the nanosponge in biomedicine. Our results shown nanosponge may display as a biosupport platform of secreting cells. This study demonstrates the potential developments of nano-topography nanosponge in optics and biomedicine.