Krsko Peter, Kaplan Jeffrey B, Libera Matthew
Department of Chemical Engineering and Materials Science, Stevens Institute of Technology, 1 Castle Point Terrace, Hoboken, NJ 07030, USA.
Acta Biomater. 2009 Feb;5(2):589-96. doi: 10.1016/j.actbio.2008.08.025. Epub 2008 Sep 21.
We constructed surface-patterned hydrogels using low-energy focused electron beams to locally crosslink poly(ethylene glycol) (PEG) thin films on silanized glass substrates. Derived from electron-beam lithography, this technique was used to create patterned hydrogels with well-defined spatial positions and degrees of swelling. We found that cells of the bacterium Staphylococcus epidermidis adhered to and grew on the silanized glass substrates. These cells did not, however, adhere to surfaces covered by high-swelling lightly crosslinked PEG hydrogels. This finding is consistent with the cell-repulsiveness generally attributed to PEGylated surfaces. In contrast, S. epidermidis cells did adhere to surfaces covered by low-swelling highly crosslinked hydrogels. By creating precise patterns of repulsive hydrogels combined with adhesive hydrogels or with exposed glass substrate, we were able to spatially control the adhesion of S. epidermidis. Significantly, adhesive areas small enough to trap single bacterial cells could be fabricated. The results suggest that the lateral confinement imposed by cell-repulsive hydrogels hindered the cell proliferation and development into larger bacterial colonies.
我们使用低能聚焦电子束构建了表面图案化水凝胶，以局部交联硅烷化玻璃基板上的聚乙二醇（PEG）薄膜。源自电子束光刻技术，该技术用于创建具有明确空间位置和溶胀度的图案化水凝胶。我们发现表皮葡萄球菌细胞粘附在硅烷化玻璃基板上并在其上生长。然而，这些细胞并未粘附在高溶胀轻度交联的PEG水凝胶覆盖的表面上。这一发现与通常归因于聚乙二醇化表面的细胞排斥性一致。相比之下，表皮葡萄球菌细胞确实粘附在低溶胀高度交联水凝胶覆盖的表面上。通过创建排斥性水凝胶与粘附性水凝胶或暴露玻璃基板相结合的精确图案，我们能够在空间上控制表皮葡萄球菌的粘附。重要的是，可以制造出小到足以捕获单个细菌细胞的粘附区域。结果表明，细胞排斥性水凝胶施加的侧向限制阻碍了细胞增殖并发展成更大的细菌菌落。
