Greca Luiz G, Rafiee Mahdi, Karakoç Alp, Lehtonen Janika, Mattos Bruno D, Tardy Blaise L, Rojas Orlando J
Department of Bioproducts and Biosystems, School of Chemical Engineering, Aalto University, P.O. Box 16300, FI-00076 Aalto, Finland.
Department of Communications and Networking, School of Electrical Engineering, Aalto University, P.O. Box 15500, FI-00076 Aalto, Finland.
ACS Nano. 2020 Oct 27;14(10):12929-12937. doi: 10.1021/acsnano.0c03999. Epub 2020 Oct 5.
Superhydrophobic surfaces are promising for preventing fouling and the formation of biofilms, with important implications in the food chain, maritime transport, and health sciences, among others. In this work, we exploit the interplay between wetting principles of superhydrophobic surfaces and microbial fouling for advanced three-dimensional (3D) biofabrication of biofilms. We utilize hydrostatic and capillary pressures to finely control the air-water interface and the aerotaxis-driven biofabrication on superhydrophobic surfaces. Superhydrophobic 3D molds are produced by a simple surface modification that partially embeds hydrophobic particles in silicone rubber. Thereafter, the molds allow the templating of the air-water interface of the culture medium, where the aerobic nanocellulose-producing bacteria () are incubated. The biofabricated replicas are hollow and seamless nanofibrous objects with a controlled morphology. Gradients of thickness, topographical feature size, and fiber orientation on the biofilm are obtained by controlling wetting, incubation time, and nutrient availability. Furthermore, we demonstrate that capillary length limitations are overcome by using pressurized closed molds, whereby a persistent air plastron allows the formation of 3D microstructures, regardless of their morphological complexity. We also demonstrate that interfacial biofabrication is maintained for at least 12 days without observable fouling of the mold surface. In summary, we achieve controlled biofouling of the air-water interface as imposed by the experimental framework under controlled wetting. The latter is central to both microorganism-based biofabrication and fouling, which are major factors connecting nanoscience, synthetic biology, and microbiology.
超疏水表面在防止污垢和生物膜形成方面具有广阔前景，在食物链、海上运输和健康科学等领域有着重要意义。在这项工作中，我们利用超疏水表面的润湿性原理与微生物污垢之间的相互作用，进行生物膜的先进三维（3D）生物制造。我们利用静水压力和毛细管压力来精确控制空气 - 水界面以及超疏水表面上的趋气性驱动生物制造。超疏水3D模具通过简单的表面改性制备，即将疏水颗粒部分嵌入硅橡胶中。此后，这些模具能够对培养基的空气 - 水界面进行模板化，在此界面上培养产有氧纳米纤维素的细菌（）。生物制造的复制品是具有可控形态的中空无缝纳米纤维物体。通过控制润湿性、培养时间和养分可用性，可在生物膜上获得厚度、地形特征尺寸和纤维取向的梯度。此外，我们证明通过使用加压封闭模具可以克服毛细管长度限制，由此一个持久的空气层允许形成3D微结构，无论其形态复杂性如何。我们还证明界面生物制造至少可维持12天，模具表面无明显污垢。总之，我们在受控润湿性下实现了实验框架所要求的空气 - 水界面的受控生物污垢。后者对于基于微生物的生物制造和污垢形成都至关重要，而这两者是连接纳米科学、合成生物学和微生物学的主要因素。
