Preclinical studies for new drug development include cell culture and animal studies. Cell culture methods are just culturing living cells on a dish; the conditions are different from cells in a real organ. In addition, the data from animal studies are not always predictive of human responses, given the different physiology and cellular functions. Only 2% of drug development failures are screened in the preclinical stage. Therefore, we need real human organ–like devices that are superior to animal models. The Organ-on-a-chip (OOC) technology has shown strong promise in mimicking the complexity of native tissues and recently significant advances have been made in applying this technology to studies of the kidney and its diseases. The main role of the kidneys is to clear endogenous waste products from the body. Exogenous drugs and toxins are often cleared via the same elimination route, making the kidney susceptible to drug-induced aberrations. The kidney-on-a-chip platform to be developed in this master thesis is fabricated using soft lithography. It consists of an apical channel separated from a bottom reservoir by an ECM-coated porous membrane upon which primary human epithelial cells are cultured. For the creation of the upper flow channel, master molds are created through photolithography of the dry photoresist Ordyl on the surface of PCB and then PDMS is cast on the masters. The bottom structure is made from a cured PDMS slab with a cut-out rectangle to serve as a medium reservoir directly beneath the microfluidic channel. Both the top and bottom structures are plasma treated to facilitate tight bonding to a porous polyester membrane in between the two compartments. The OOC model of renal nephrotoxicity is considered the most suitable model to mimic kidney physiology for drug screening, yet the lack of real-time monitoring is one of the biggest challenges in OOC technology. Currently, most approaches rely on off-chip analysis and imaging techniques. However, the urgent demand for continuous, noninvasive, and real-time monitoring of cell growth and cell response to drugs constructs requires the direct integration of biosensors. KIM-1 (kidney injury molecule 1) is a protein that is expressed at low levels in the kidney, but it is significantly upregulated when the kidney undergoes injury. Therefore, KIM-1 is a promising biomarker for the early detection of acute kidney injury. In this work, KIM-1 sensors based on graphene oxide will be developed, on which immobilization of probe biomolecules (antibodies against KIM-1) will occur. Thus KIM-1 will be captured by the probe biomolecules immobilized on the sensor and a resistance reduction will be measured, signaling cell damage.

The MSc Thesis of Giorgos Baklαvas concerns the study of intermolecular interactions between metal clusters in the crystal lattice by using the Hirshfeld method. The MSc thesis is in progress and will be submitted to the Department of Chemistry of the National and Kapodistrian University of Athens.

Many composite and natural materials have a fibrous structure, i.e. they consist of complex networks of fibres in different layers. In the case that the diameter of fibres is less than 100nm we are talking about nanofibrous materials. One of the common methods to characterize and study these materials is their imaging with top-down Scanning Electron Microscope images. 

The first aim of this work is to investigate the randomness of the fibrous network and its effects on the spatial dispersion of the intersections of the fibres and the characteristics (density, size) of the pores. Secondly, to identify the presence of randomness in the limited field of SEM images and to define criteria for its recognition and methods for its quantification by means of such SEM images.