Research

Research context / Theoretical framework Controlling and understanding adhesion of cells on artificial surfaces remains as a critical topic in materials and life sciences. In this regard, combination of top-down (contact printing) and bottom-up approaches (ATRP polymerization + layer-by-layer adsorption of polyelectrolytes and proteins) appears as a promising strategy for the design and fabrication of cell-appealing interfaces. Interestingly, this methodology allows going from 2D to 3D-like hierarchical structures of hybrid content (niches) that influence a subsequent cell attachment on top, by better exposing the specific binding sites (RGD, IKVAV moieties) towards target membrane receptors (i.e. integrins, CD44). Complementary use of Atomic Force Microscopy (AFM), with a living cell as probe, together with Quartz Crystal Microbalance with Dissipation (QCM-D), will enable an early-stage analysis and quantification of these cell-substrate interactions on the nanoscale. Hypotheses/ Research questions / Objectives The main hypotheses of the project are the following: i) Combination of substrate-anchored polymer brushes and layer-by-layer deposited polyelectrolyte chains give rise to soft 3D niches for the enhanced adsorption of ECM proteins. The transformation of 2D interfaces into 3D-like architectures will, in turn, enhance cell attachment and proliferation of cells, with particular impact on both cell morphology and the number of cell-substrate connections formed; ii) The use of Contact-Printing techniques before the grafting-from of the brushes allows the fabrication of localized individual 3D attachment points. The localized presence of specific molecules will influence the cell-substrate affinity with final impact on cell morphology and the establishment of a different number of cell-surface contacts; iii) Single-Cell Probe Force Spectroscopy (SCPFS) technique is sensitive enough to identify early stage attachment events in cell-substrate contacts. The use of a living cell acting as indenting probe will determine events taking place on the nano- and microscale. Approach / Methods The following methods will be used to study substrate preparation and cell adhesive behaviour: Atomic force microscopy (AFM) in SCPFS mode, (confocal) fluorescence microscopy, quartz crystal microbalance with dissipation (QCMD), scanning electron microscopy (SEM), and cell culture protocols.

Nanomaterials and other innovative materials (advanced materials) offer interesting application possibilities and functions. They are therefore increasingly being used in new products and in many industrial sectors. However, the possible undesirable consequences must also be carefully studied and evaluated. The accompanying project to NanoTrust-Advanced investigates safety and risk-relevant aspects of nanomaterials and advanced materials, which are regularly published in the established NanoTrust dossiers and fed into the national Nanoinformation Commission of the Ministry of Health, the working group on nano-worker protection of the AUVA or the standardization group "Nanotechnology" of the Austrian Standards Institute. The inter- and transdisciplinary exchange of knowledge and experience that takes place here at many levels and in numerous committees thus contributes to the safe and sustainable development of these new materials.

The basis for our technology is the so-called inline holography microscopy. We shine coherent light through a transparent volume with microscopic objects like bacteria, spores, algae, microplastics, etc. in it. These objects scatter a small amount of this light. The scattered light interferes with the illumination beam, creating interference patterns that are recorded by a camera. The breakthrough technology to be further developed in this project uses recorded in-line holograms to calculate the full light field in the entire sample volume by backpropagation or numerical refocusing. This offers several advantages: 1. the ability to numerically refocus after image acquisition greatly simplifies data acquisition. 2. cells and environmental particles can be observed in their natural 3D environment. 3. it is possible to observe many more objects simultaneously than is possible with conventional microscopy, and it is possible to record a continuous flow of an analyzed fluid. Based on the data collected with this technology, Holloid aims to develop algorithms that will allow researchers and environmental analysts to simultaneously detect and quantify bacteria and microparticles using a microscope/sensor suitable for environmental monitoring, including groundwater. This will provide a new means for those responsible for water quality in the environment and, ultimately, in drinking water to gain insights with significant implications for the health of our ecosystems and people. Ultimately, the results of this project can form the basis for numerous other applications in environmental monitoring and beyond.