Effects on Lettuce Yield Parameters and Toxicological Safety Assessment of a Plant-Derived Formulation Based on Rosemary and Eucalyptus Essential Oils

Essential oils from medicinal and aromatic plants are increasingly recognized as a promising class of green molecules for use in crop production. In many cases, the beneficial aspects of a substance are not supported by sufficient toxicological safety testing, even though recent reports suggest that some compounds may be toxic to terrestrial or aquatic non-target species. It is, therefore, essential to investigate the possibility of adverse effects on non-target animals and humans exposed to these substances through the consumption of fruit and/or vegetables. The present study aims to examine the potential effects on yield and quality parameters and investigate the level of in vitro and in vivo toxicity of an Eco-product (EP) based on rosemary and eucalyptus essential oils, to provide a measure for safe use in the agricultural sector. The product was evaluated in lettuce crop production and indicated that one-time application of the EP formula increases yield, activating various secondary metabolism pathways of the plant to cope with oxidative stress. Cytotoxicity assays and in vivo acute oral and dermal toxicity studies suggest that the tested compound does not pose any significant health hazard, and the dissolved product can be classified in Category 5, according to the Globally Harmonized System of Classification and Labelling of Chemicals (GHS)

Inverted Perovskite Photovoltaics Using Flame Spray Pyrolysis Solution Based CuAlO2/Cu−O Hole-Selective Contact

We present the functionalization process of a conductive and transparent CuAlO2/Cu-O hole-transporting layer (HTL). The CuAlO2/Cu-O powders were developed by flame spray pyrolysis and their stabilized dispersions were treated by sonication and centrifugation methods. We show that when the supernatant part of the treated CuAlO2/Cu-O dispersions is used for the development of CuAlO2/Cu-O HTLs the corresponding inverted perovskite-based solar cells show improved functionality and power conversion efficiency of up to 16.3% with negligible hysteresis effect

Coronary Stents Crack and Corrode in vivo: A Structural Integrity and Tissue Inflammation Analysis

Even though stents are routinely used in the majority of cardiovascular catheterization procedures to treat stenotic arteries, their clinical effectiveness is hindered by numerous post deployment complications such as biocorrosion and structural failure, which may lead to inflammation, thrombosis and ultimately in-stent restenosis (ISR). Recent studies on explanted stents obtained from human cadavers have revealed that stents undergo corrosion and fatigue-induced fracture in vivo, with significant release of metallic ions into surrounding tissues. Corrosion by-products such as metallic ions and particulates could alter the local tissue environment leading to upregulation of proinflammatory factors and potentially promoting ISR. To investigate the role of biomechanical loading and its contribution to increased fatigue wear of stents, accelerated pulsatile durability tests were carried out on commercially available stents in a simulated physiological environment. Potential spatial variations in the mechanical properties on stent struts and their role in the observed premature failures of the stent devices during operation were also examined. Fretting wear and fatigue-induced fractures were found on stent surfaces after exposure to cyclic loading similar to that arising in vivo. Biomechanical factors such as arterial curvature combined with stent overlapping enhance the incidence and degree of wear and fatigue fracture. Nanoindentation studies performed on various locations along the stent struts have shown that the hardness of specific stent locations significantly increases after mechanical expansion. The increase in hardness was associated with a reduction of the material‘s ability to dissipate energy in plastic deformations, therefore an increased vulnerability to fracture and fatigue. It was concluded that the locations of fatigue fractures in stent struts are controlled not only by the geometrically-driven stress concentrations developing during cyclic loading but also by the local material mechanical changes that are imparted on various parts of the stent during the deployment process. Additionally, the project focused on investigating potential mechanisms and regulatory factors involved in the development of in-stent restenosis. The effect of stent corrosion was investigated in an animal model in order to explore a possible link between metal ion release, inflammation, and factors thought to initiate ISR. To evaluate the vessel inflammatory response, miniature stents with active corrosion were implanted in mice abdominal aortas and novel in vivo imaging techniques were employed to assess the trafficking and accumulation of fluorescent donor monocytes as well as the proliferation of vascular smooth muscle cells at the implantation site. The in vivo imaging analysis revealed that elevated metal particle contamination, prompted by corroded stents, triggers an inflammatory response and promotes monocyte recruitment and neointimal proliferation at the site of injury. The results suggest that when stents corrode in vivo, the generated active microenvironment promotes inflammation that may lead to the development of in-stent restenosis. The project findings are consistent with what has been recently reported regarding the condition of explanted stents from human cadavers, proposing the need for optimization of future stent designs and modification of current regulatory testing guidelines. Future work will focus on developing novel strategies to address the serious complications arising from the ubiquitous use of cardiovascular stent implants. This will eventually lead to the design of new biofunctional stent platforms that will help the millions of cardiac patients worldwide who suffer from ISR complications.Committee Member (President) Andrew Nicolaides, Committee MemberTasos GeorgiadesComplete

Effects on Lettuce Yield Parameters and Toxicological Safety Assessment of a Plant-Derived Formulation Based on Rosemary and Eucalyptus Essential Oils

Essential oils from medicinal and aromatic plants are increasingly recognized as a promising class of green molecules for use in crop production. In many cases, the beneficial aspects of a substance are not supported by sufficient toxicological safety testing, even though recent reports suggest that some compounds may be toxic to terrestrial or aquatic non-target species. It is, therefore, essential to investigate the possibility of adverse effects on non-target animals and humans exposed to these substances through the consumption of fruit and/or vegetables. The present study aims to examine the potential effects on yield and quality parameters and investigate the level of in vitro and in vivo toxicity of an Eco-product (EP) based on rosemary and eucalyptus essential oils, to provide a measure for safe use in the agricultural sector. The product was evaluated in lettuce crop production and indicated that one-time application of the EP formula increases yield, activating various secondary metabolism pathways of the plant to cope with oxidative stress. Cytotoxicity assays and in vivo acute oral and dermal toxicity studies suggest that the tested compound does not pose any significant health hazard, and the dissolved product can be classified in Category 5, according to the Globally Harmonized System of Classification and Labelling of Chemicals (GHS)

Monitoring tumor burden by multicolor in vivo flow cytometry

In vivo measurement of tumor burden, both in cancer research models and in patients, is an important parameter for the accurate assessment of disease progression and the response to therapeutic intervention [1]. Several in vivo imaging modalities have been utilized in the assessment of tumor burden, including functional magnetic resonance imaging, computer tomography and positron emission tomography [2, 3], fluorescence imaging [4, 5], intravital microscopy [6] and bioluminescence imaging [7]. More recently, the detection/quantification of circulating cancer cells has been explored as a method to evaluate tumor burden in the context of assessing disease stage, prognosis as well as monitoring disease progression following therapeutic intervention in cancer patients [8, 9]. Clinically, various ex vivo assays have been developed to detect cancer cells shed in circulation by primary tumors, including breast cancer, prostate cancer and small-cell lung cancer [10, 11]. In vivo flow cytometry has been developed as a method for real-time detection of circulating cancer cells injected into the circulation of experimental animals. The method does not require extraction of blood samples and is therefore well suited for long-term monitoring of circulating tumor cells. In this report, we report on the development of a multichannel in vivo flow cytometer to detect and quantify circulating cancer cells as a means of assessing the tumor burden in animal models

Facilitating the development of novel therapeutic strategies via in vivo optical imaging techniques

The BioLISYS Laboratory at CUT is developing novel fluorescence-based techniques for in vivo imaging of small animals with applications in cardiovascular and cancer therapeutics. These include the development of an in vivo flow cytometer in order to monitor fluorescently labeled cells in circulation as well as a whole body reflectance imaging system for detection of fluorescence and bioluminescence signal from cells and tissues in murine models of disease. The in vivo flow cytometer has been designed as a minimally invasive optical tool for the real time detection/quantification of fluorescent cells in circulation of living animals without the need to sequentially extract blood samples or sacrifice animals. Thus the system allows for the continuous monitoring of a cell population of interest over long time periods in order to assess dynamic changes in circulation. The optical reflectance imaging system combines fluorescence and bioluminescence imaging capabilities with a large field of view in order to enable imaging over a wide area of the animal. The noninvasive, quantitative method enables longitudinal studies of physiological changes in disease and allows for continuous monitoring in the same mouse over an extended time period, in order to evaluate biodistribution and therapeutic response of experimental therapeutic agents. The imaging systems have been employed in the in vivo analysis of cardiovascular implants and novel biomaterials in order to evaluate the inflammatory response of vascular tissue to stent implantation and stent biocorrosion via the in vivo monitoring of the degree of inflammation, macrophage infiltration and cytokine expression in tissue surrounding stents deployed in mice abdominal aortas. In cancer therapeutics, the in vivo imaging systems have been used to develop a novel therapeutic system for targeted miRNA delivery to tumors, via microparticles that are derived from mesenchymal stem cells. Fluorescently labeled miRNA-loaded microparticles injected into the tail vein of tumor bearing mouse were monitored in circulation via the in vivo flow cytometer while their biodistribution and targeting specificity was detected in tumor sites via the fluorescence based whole body reflectance imaging system. Furthermore, tumor progression and therapeutic response to miRNA therapy delivered via local and systemic administration of the MSC-derived microparticles was monitored in real time via the imaging of fluorescence and bioluminescence expressing tumors by whole body reflectance imaging