A Window to Understanding Abiotic-Biotic Interfaces, Creation of Nanostructured Interface Arrays for Multimodal Imaging and Characterization of Pathogen-Surface Interactions

Optimizing the surface topography and chemistry of materials that contact biological systems is profoundly important to our energy, health, and food securities. Whether one is trying to promote growth or prevent fouling, garnering a deeper understanding of the fundamental mechanisms for biological attachment and the subsequent cascade of physical and chemical events that shape biological processes is essential to optimizing the design and manufacturing of materials. Here we describe efforts to enable an integrated workflow focused on developing detailed information about the mechanisms of protein adsorption, initial attachment, propagation, and persistence of pathogens on abiotic interfaces while also accelerating the design and manufacturing of materials that inhibit those events. Specifically, we describe the development of nanostructured interface arrays that are built to display multiple, well-tuned topographies and surface chemistries and their use in enabling rapid screening and multimodal characterization of pathogen-material interactions. Work describes the design, fabrication, and testing of these nanostructured arrays, created on suspended silicon nitride membranes, for their durability and compatibility with optical, atomic force, and electron microscopy. Successful treatment and testing of the interface arrays to understand biofilm formation has been demonstrated in both stagnant and controlled flow conditions, using microfluidics. The 40 nm-thick silicon nitride membranes are robust and can withstand all the soaking, rinsing, and drying steps necessary for collecting time-course measurements of the dynamic biofilm formation process. Nanostructuring of the surfaces does not compromise the mechanical stability of the suspended membranes and allows rapid screening of the impact of surface topography on biofilm formation via correlated optical and multimodal large area atomic force microscopy (AFM) imaging. Interface arrays and sample holders that enable analysis across sample characterization modalities will allow rapid study of the dynamic nature of pathogen-surface interactions and will be made broadly available through the user program at the Center for Nanophase Materials Sciences. To interpret our direct observations, we are using simulations along with artificial intelligence and machine learning (AI/ML) to predict dynamic processes, link together ‘snapshots,’ and feedback into interface design. Ultimately, we will connect observed molecular and structural changes at the pathogen-material interface with biological and chemical signatures associated with changes in phenotype.