Efficiency of Expired Drugs Used as Corrosion Inhibitors: A Review.

Corrosion inhibitors represent one of the most commonly used methods for significantly reducing the corrosion rate of metals and alloys. Adsorption inhibitors have a wide range of applications in cooling water systems, deicing solutions for aircrafts, airports and ways, etching and degreasing solutions, oil pipelines, paints and coatings and metal processing solutions. Adsorption corrosion inhibitors of metals and alloys are generally organic compounds that contain structures with heteroatoms (N, P, S, As, O) in their molecules, having lone pair electrons or π electrons in aromatic rings or multiple bonds. They enable relatively strong interactions between the metal atoms and organic molecules, resulting in a protective layer of organic molecules adsorbed at the metal-corrosive solution interface. Most molecules of active substances from drugs contain similar structures, which is why many drugs have been already tested as corrosion inhibitors. One of the major disadvantages of using drugs for this purpose is their particularly high price. To overcome this impediment, the possibility of using expired drugs as corrosion inhibitors has been investigated since 2009. The present paper is an exhaustive compilation of the scientific published papers devoted to the use of expired drugs as corrosion inhibitors in various aggressive solutions. The inhibitory efficiencies of expired drugs are presented as a function of the studied metal or alloy and the nature of the aggressive solution, as well as the concentration of the inhibitor in such a solution. Research has especially been focused on mild and carbon steel and less on stainless steel, as well as on some metals such as copper, zinc, nickel, tin and aluminum and its alloys. The experimental methods used to assess the inhibitory efficiencies of expired drugs are briefly discussed. Also, the available information on the stability of the active substances in the drugs is presented, although most authors were not concerned with this aspect. Finally, several actions are revealed that must be undertaken by researchers so that the results obtained in the study of the anticorrosive action of expired drugs can be applied at the industrial level and not remain only an academic concern.

In Vitro Study of the Multimodal Effect of Na+/K+ ATPase Blocker Ouabain on the Tumor Microenvironment and Malignant Cells.

Na+/K+ ATPase is a protein involved in the active transport of ions across the cellular membrane. Ouabain is a cardiotonic glycoside that, by inhibiting the Na+/K+ pump, interferes with cell processes mediated directly by the pump, but also indirectly influences other cellular processes such as cell cycle and proliferation, growth, cell differentiation, angiogenesis, migration, adhesion, and invasion. We used the SK-BR-3 breast cancer cell line, mesenchymal stem cells (MSCs), and tumor-associated fibroblasts (TAFs) in vitro to determine the effects of ouabain exposure on these cellular types. The results showed a multi-level effect of ouabain mainly on tumor cells, in a dose-dependent manner, while the TAFs and their normal counterparts were not significantly influenced. Following exposure to ouabain, the SK-BR-3 cells changed their morphologic appearance, decreased the expression of immunophenotypic markers (CD29, Her2, VEGF), the proliferation rate was significantly decreased (Ki67 index), the cells were blocked in the G0 phase of the cell cycle and suffered necrosis. These data were correlated with the variable expression of α and ß Na+/K+ pump subunits in tumor cells, resulting in decreased ability to adhere to the VCAM-1 substrate in functional flow chamber studies. Being indicative of the pro-apoptotic and inhibitory effect of ouabain on tumor invasion and metastasis, the results support the addition of ouabain to the oncological therapeutic arsenal, trailing the "repurposing drugs" approach.

Decellularized Extracellular Matrix Scaffolds for Cardiovascular Tissue Engineering: Current Techniques and Challenges.

Cardiovascular diseases are the leading cause of global mortality. Over the past two decades, researchers have tried to provide novel solutions for end-stage heart failure to address cardiac transplantation hurdles such as donor organ shortage, chronic rejection, and life-long immunosuppression. Cardiac decellularized extracellular matrix (dECM) has been widely explored as a promising approach in tissue-regenerative medicine because of its remarkable similarity to the original tissue. Optimized decellularization protocols combining physical, chemical, and enzymatic agents have been developed to obtain the perfect balance between cell removal, ECM composition, and function maintenance. However, proper assessment of decellularized tissue composition is still needed before clinical translation. Recellularizing the acellular scaffold with organ-specific cells and evaluating the extent of cardiomyocyte repopulation is also challenging. This review aims to discuss the existing literature on decellularized cardiac scaffolds, especially on the advantages and methods of preparation, pointing out areas for improvement. Finally, an overview of the state of research regarding the application of cardiac dECM and future challenges in bioengineering a human heart suitable for transplantation is provided.

Optimization of Complete Rat Heart Decellularization Using Artificial Neural Networks.

Whole organ decellularization techniques have facilitated the fabrication of extracellular matrices (ECMs) for engineering new organs. Unfortunately, there is no objective gold standard evaluation of the scaffold without applying a destructive method such as histological analysis or DNA removal quantification of the dry tissue. Our proposal is a software application using deep convolutional neural networks (DCNN) to distinguish between different stages of decellularization, determining the exact moment of completion. Hearts from male Sprague Dawley rats (n = 10) were decellularized using 1% sodium dodecyl sulfate (SDS) in a modified Langendorff device in the presence of an alternating rectangular electric field. Spectrophotometric measurements of deoxyribonucleic acid (DNA) and total proteins concentration from the decellularization solution were taken every 30 min. A monitoring system supervised the sessions, collecting a large number of photos saved in corresponding folders. This system aimed to prove a strong correlation between the data gathered by spectrophotometry and the state of the heart that could be visualized with an OpenCV-based spectrometer. A decellularization completion metric was built using a DCNN based classifier model trained using an image set comprising thousands of photos. Optimizing the decellularization process using a machine learning approach launches exponential progress in tissue bioengineering research.

Development of a high-performance anesthesia ventilator for research in small animals.

INTRODUCTION: Small animal models are used extensively in basic research because of their low cost and possibility to mimic several human pathologies. These models are used to either analyze the underlying mechanisms and/or assess therapeutic approaches. In this respect, gentle and safe artificial ventilation is mandatory, especially for prolonged experimental procedures that require the survival of the animals. The aim of the present paper was to develop and validate a high-performance anesthesia ventilator for small animals. METHODS: A pressure-controlled ventilator with assisted ventilation and deep breath modulated on a scheduled basis and a PEEP facility for an improved anesthetic management was developed. Parameters of acid-base balance and arterial blood gases were measured initially at the end of arterial catheterization and monitored throughout the experiment. RESULTS: Our data show the following average values (mmHg) for pO2: 440 +/- 45 (initial), 378 +/- 24 (2 h), 373 +/- 22 (4 h), and 375 +/- 28 (6 h) and for pCO2: 35 +/- 3 (initial), 34 +/- 5 (2 h), 38 +/- 5 (4 h), and 40 +/- 6 (6 h), respectively. CONCLUSIONS: We describe the procedure for the manufacture of a reliable, high-performance anesthesia ventilator that facilitates recovery of spontaneous respiration at animal arousal with preservation of normal blood gases values and no damage to the lungs.

Adipocytes differentiated in vitro from rat mesenchymal stem cells lack essential free fatty acids compared to adult adipocytes.

Adult bone marrow mesenchymal stem cells (BMSCs) can be differentiated in vitro to become adipocyte-like cells with lipid vacuoles, similar to adipocytes derived from adult adipose tissue. Little is known regarding the composition of free fatty acids (FFAs) of the in vitro-differentiated adipocytes, or whether it resembles that of native adult adipocytes. We used gas chromatography-mass spectrometry to identify FFA species in BMSC-derived adipocytes and compared them with FFAs found in adipocytes derived from adult adipose tissue. We found that adult adipocytes contained significant percentages of saturated and monounsaturated FFAs, including palmitic acid (C16:0), stearic acid (C18:0), and oleic acid (C18:1); some polyunsaturated FFAs, such as linoleic acid (C18:2), a small percentage of arachidonic acid (C20:4), and very little linolenic acid (C18:3). In comparison, 80%-90% confluent BMSCs contained comparable percentages of palmitic and oleic acids, significantly more arachidonic and stearic acids, very little linoleic acid, and no linolenic acid. After differentiation, compared with adult adipocytes, BMSC-derived adipocytes contained a comparable percentage of palmitic acid, more stearic and arachidonic acids, less oleic acid, almost no linoleic acid, and no detectable linolenic acid. This composition was quite similar to that of undifferentiated BMSCs. The differentiation medium contained only palmitic and stearic acids, with traces of oleic acid; it did not contain the essential polyunsaturated fatty acids. Thus, the composition of FFAs in BMSC-derived adipocytes was altered compared with adult adipocytes. BMSC-derived adipocytes had an altered composition of saturated and monounsaturated FFAs and lacked essential FFAs that may directly affect signaling related to their lipolysis/lipogenesis functions.

Artificial device for extracorporeal blood oxygenation in rats.

Blood oxygenation devices are an essential component of any cardiopulomonary bypass circuit in various species of laboratory animals. When using larger animals like dogs or pigs, the human and pediatric blood oxygenators could be easily used, but the disadvantage of these species is the scarcity of biochemical and genetic assays for experimental follow-up. However, small rodents like rats have plenty of biochemical assays, but their size requires special oxygenators adapted for their small blood volume and often primed with blood of another animal or other physiological solution. We showed the new design of a blood oxygenator with direct blood-gas contact in an open circuit, specially designed for rats in which the blood oxygenation takes place in a slowly rotating plastic tube with blood spread onto its inner walls in a thin layer. The oxygenator is simple and efficient, does not require priming with the blood of another rat, has a small dead volume, is reusable, and easy to clean and sterilize.