CNRS, LAAS, Toulouse, France.
Nanotechnology. 2011 Sep 30;22(39):395102. doi: 10.1088/0957-4484/22/39/395102. Epub 2011 Sep 2.
Immobilization of live micro-organisms on solid substrates is an important prerequisite for atomic force microscopy (AFM) bio-experiments. The method employed must immobilize the cells firmly enough to enable them to withstand the lateral friction forces exerted by the tip during scanning but without denaturing the cell interface. In this work, a generic method for the assembly of living cells on specific areas of substrates is proposed. It consists in assembling the living cells within the patterns of microstructured, functionalized poly-dimethylsiloxane (PDMS) stamps using convective/capillary deposition. This versatile approach is validated by applying it to two systems of foremost importance in biotechnology and medicine: Saccharomyces cerevisiae yeasts and Aspergillus fumigatus fungal spores. We show that this method allows multiplexing AFM nanomechanical measurements by force spectroscopy on S. cerevisiae yeasts and high-resolution AFM imaging of germinated Aspergillus conidia in buffer medium. These two examples clearly demonstrate the immense potential of micro-organism assembly on functionalized, microstructured PDMS stamps by convective/capillary deposition for performing rigorous AFM bio-experiments on living cells.
将活微生物固定在固体基质上是原子力显微镜（AFM）生物实验的重要前提。所采用的方法必须将细胞固定得足够牢固，以使其能够承受针尖在扫描过程中施加的侧向摩擦力，但又不会使细胞界面变性。在这项工作中，提出了一种将活细胞组装到基质特定区域的通用方法。它包括使用对流/毛细沉积将活细胞组装到微结构化、功能化的聚二甲基硅氧烷（PDMS）印章的图案中。这种多功能方法通过将其应用于生物技术和医学中两个最重要的系统（酿酒酵母和烟曲霉真菌孢子）得到了验证。我们表明，该方法允许通过力谱法对酿酒酵母进行多重 AFM 纳米力学测量，并在缓冲介质中对发芽的曲霉菌进行高分辨率 AFM 成像。这两个例子清楚地表明了通过对流/毛细沉积将微生物组装到功能化、微结构化的 PDMS 印章上的巨大潜力，可用于对活细胞进行严格的 AFM 生物实验。
