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Manyetit (Fe3O4) manyetik nanomalzemelerin boyut değişiminin çalışma koşullarına bağlı incelenmesi
Manyetik nanomalzemelerin (MNP) biyomedikal uygulamaları 30 yıldan fazla bir süredir araştırılmaktadır. MNP'ler tıpta; ilaç hedefleme sistemleri, hipertermi, biyosensör, manyetik hücre ayırma ve manyetik rezonans görüntülemede (MRG) kontrast ajanları gibi birçok alanda kullanılmaktadır. Özellikle vücut içi MNP kullanımında manyetik malzemelerin küçük boyutlu olması istenmektedir. Bu malzemelere kaplama yapıldığında ya da ilaç bağlandığında boyutu artmaktadır. MNP ne kadar küçük boyutta üretilirse kaplama sonrası vücut içi kullanım olasılığı o kadar artmaktadır. Bu çalışma MNP'lerin boyut değişiminin çalışma koşullarına bağlı değişimini incelemek amacıyla yapılmıştır. Birlikte çökelme yöntemi ile elde edilecek manyetik nanomalzemelerin pH, sıcaklık, karıştırma hızı ve kullanılan bazın türü gibi koşullar değiştirilerek boyut değişimi izlenmiştir. Ayrıca bu boyut değişimleri manyetik nanomalzemelerin termal özelliklerini, mekanik özelliklerini, optik özelliklerini elektrik özelliklerini ve manyetik özelliklerini değiştirecektir. Yeni özellikler yeni uygulama alanları doğuracaktır. Bu değişimler sayesinde hangi koşullarda en iyi özelliklere sahip olan ve en küçük boyutta manyetik nanomalzemenin oluştuğu tespit edilmiştir. Farklı çalışma koşulları kullanılarak elde edilen örneklerin karakterizasyon testlerinde; XRD ile sentezlenen MNP'lerin manyetit (Fe3O4) olup olmadığı kontrol edilmiştir. FESEM, demir oksit çekirdeğinin morfolojisini gözlemlemeye ve gerçek çapını tahmin etmeye izin verir. SEM analizinde MNP' lerin küresel yapıda olup olmadıkları ve MNP çekirdeklerin çapları dolayısıyla boyutları ölçülmüştür. MNP' lerin ön boyut incelenmesi dispersiyon durumundaki nanoparçacıkların hidrodinamik çapını ölçen dinamik ışık saçılımı (DLS) ile karakterize edilmiştir. VSM analizinde oda sıcaklığında elde edilen manyetizasyonun, manyetik alanla değişimine bakılarak MNP' lerin manyetik davranışları belirlenmiştir. Tanecikler arasındaki itme ve çekme değerine etkisi olan yüzey yükü zeta (ζ) potansiyel analizi ile karakterize edilmiştir.
Farklı katyonlarla çapraz bağlanmış aljinat boncuklarının şişme özelliklerinin karşılaştırılması
Polymers are widely employed in many different applications, they are difficult to recycle and generally are not biodegradable. Scientific interest in creating biodegradable and biocompatible polymers has increased, especially for use in biology and medicine, because they come from natural sources, also they are non-toxic and environmentally benign, so we can make hydrogel from them. Superabsorbent polymers can be made by improving the characteristics of hydrogels, which are three-dimensional cross-linked structures with exceptional water retention. It plays important role in nutrients, medical, tissue engineering and protection of the environment, naturally occurring polysaccharide that is derived from brown algae and bacteria. It is essential in biological uses like wound healing, medication delivery and tissue regeneration because it has special qualities like gelling, moisture retention and film-forming capacity. Aqueous alginate solutions are preferred due to the biocompatibility and flexibility in crosslinking. Also, their mechanical strength, permeability and functional properties through the incorporation of organic and inorganic materials or the application of diverse crosslinking strategies. They combined with synthetic polymers demonstrate enhanced mechanical strength and healing properties, facilitating increased tissue regeneration and regulated drug release. Even with specific disadvantages like lower carrying ability, novel developments in alginate compounds are expanding their uses, especially in the fields of renewable material development and wound healing. Alginate beads have been cross-linked using different cations, including calcium, which has strong antibacterial properties. Beads may affect the wound healing purposes and are increased by presence of certain particles, which have the ability to regulate or making small changes, typically, so as to improve it or take it less excessive to the immune system response and antibacterial properties. Flexible framework for creating biologically compatible substances have built-in antibacterial characteristics appropriate for a range of biomedical applications were provided using cation cross-linked alginate materials. In this study, 2% alginate solution was used for crosslinking with different cations to produce beads, these beads were applied by swelling test in different solution. And by comparing their antibacterial properties, the current study aims to figure out if the cation selection influences the antibacterial property of the beads and how they inhibit bacterial growth.
Aljinat-argil kompozitlerinde knisel bir kaplama yöntemiyle hazırlanan riboflavinin kontrollü salımı
Riboflavin is important for energy production and metabolic mechanisms and is considered an essential element. Alginate and montmorillonite are natural materials used as bio-based carriers due to their inherent properties. biocompatibility, and the ability to release active ingredients from the formulation in a controlled release. This study aimed to develop a controlled-release system for riboflavin using an encapsulation method using sodium alginate, which has high gelling properties, and montmorillonite (MMT), in the presence of carboxymethylcellulose (CMC), bound to calcium ions. The goal was to improve stability and bioavailability through a sustainable and biocompatible system. The release kinetic and encapsulation efficiency of beads were examined in simulated gastrointestinal media. The results. show that hydrogel matrix encapsulation of riboflavin ensures a sustained release rate and good pH protection, following zero-order kinetics. The formula in this study has a significant potential for applications in the pharmaceutical and food industries, as well as high-efficiency packaging solutions.
In-vitro effects of orange peel extracts on candida albicans, a major source of fungal infections
Candida albicans is the part of our natural microflora but also responsible for mucosal and systematic infections that can lead to death in individuals with malnutrition, diabetes and immunocompromised individuals. These are the most common species which cause nosocomial diseases and are capable of developing resistance to antifungal antibiotics. The mechanism of action of antifungal drugs to be used against fungal infections are different from antibacterial drugs as fungi are eukaryotes and bacteria are prokaryotes. It is the first study to identify the dose range with the antifungal effect of various orange peel extracts in Candida fungus and the most appropriate orange extract to be studied using infrared spectroscopy with chemometric analysis, to find out the structural and functional effects of orange extract in fungal biomolecules with detailed spectral characterization. Thus, a novel method that can monitor the antifungal effect can be proposed with this study. Based on the results of disc diffusion and microtubule dilution tests, we determined the concentration of the orange extract that we use for IR spectrum analysis which are OE50%, OE25%, OE12.5%, OE6% and two other groups named control (C) along with Candida (CA). Different orange extract doses can show antifungal effects on Candida albicans by effecting the molecular structure and composition of the components of yeast. The most effected components were seen as saturated and unsaturated lipids with triglycerides. In contrast, the protein components of yeast seem to be not affected significantly from the antifungal effects of OE. There is a dose difference in the antifungal effects of orange extract on Candida albicans samples. The best doses for the antifungal activity were determined as medium doses (25 % and 12,5 %) especially 25% OE dose. The highest (50%) and lowest (6%) doses show opposite effects on yeast when compared to the medium doses. The optimal antifungal effect was seen with medium OE doses (12,5% and 25%) by affecting the saturated and unsaturated lipid concentration and composition of C. albicans. The protein changes were related to the changes of lipid metabolism of yeast related to the enzymes and regulatory proteins of that metabolism. There was no dose effect in the changes of nucleic acid and carbohydrate contents except low dose of OE (6%) which shows opposite effect for those parameters when compared to the other doses of OE. The results of this study also showed that ATR-FTIR spectroscopy has the capacity to distinguish the antifungal effects of different doses of orange extract samples on the composition of Candida albicans species. Keywords: Candida Albicans, Orange Peel Extracts, Fungal Infections, FTIR Spectroscopy
Schizochytrium sp.'den ekstrakte edilen lipitlerin antimikrobiyal ve anti-biyofilm aktiviteleri. S31 mikroalgi
Biotechnology has been developing tools and procedures for the benefit of living things for many years. In most of these studies, the production of essential metabolic compounds is prioritized for human health. One of the crucial substances for human health that has gained popularity recently is omega-3 fatty acids. Alternative sources of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) have been searched since fish oils, the main commercial sources of omega-3 fatty acids, have heavy metal content, especially mercury, limited availability, and an unpleasant odor. Schizochytrium sp. S31 is a microalga with a high concentration of polyunsaturated fatty acids, particularly DHA. Because of its high DHA content and low heavy metal levels, heterotrophic cultivation of Schizochytrium sp. S31 provides an excellent opportunity to provide alternative omega-3 sources. It also contains a variety of bioactive substances that can be utilized as medicinal raw materials, food additives, animal feed, biodiesel and antimicrobial agents. In this study, optimum conditions were applied to cultivate Schizochytrium sp. S31 heterotrophically and the nutritional composition of the dry biomass were analysed. According to the results, 45% protein, 5% total fat and 37% carbohydrate were obtained. Downstream processes, including cell lysis and lipid extraction, were adjusted in order to increase overall lipid content of Schizochytrium sp. S31. Five distinct solvent mixtures—hexane, hexane/ethanol (2:1), ethanol, methanol, and hexane/methanol (2:1)—as well as two different cell lysis techniques —mortar and pestle and ultrasonication—were examined and compared. Based on the results of cell lysis and lipid extraction, ultrasonication of hexane /methanol (2:1) enhanced the total lipid yields to 34% with a transparent appearance. According to the GCMS analysis results, 10.4% DHA and 16.11% EPA fatty acids were obtained. Total Omega-3 Fatty Acids and Total Omega-3 + Omega-6 Fatty Acids ratio were calculated as 27.42% and 32.15% respectively. The antibacterial effects of Schizochytrium sp. S31 oil samples were also investigated on Gram-negative pathogens, Pseudomonas aeruginosa, Escherichia coli 35218 and Klebsiella pneumonia, which cause many different human infections, as well as the Gram-positive pathogen Streptococcus mutans. At the same time, their effects on biofilm formation in Pseudomonas aeruginosa, Escherichia coli 35218 bacteria were investigated. The Schizochytrium sp. S31 oil sample was found to have anti-pathogenic activity on pathogenic bacteria of Pseudomonas aeruginosa, Escherichia coli 35218, Klebsiella pneumonia and Streptococcus mutans. The surface adhesion ability and biofilm formation capability of P. aeruginosa and Escherichia coli 35218 strain, which are widely employed as model bacteria in biofilm research, were dramatically inhibited in the presence of a Schizochytrium sp. S31 oil sample.
Detection of chemometric markers in liver tissue using infrared spectroscopy
Among the leading contributors of fetal alcohol spectrum disorder (FASD) is perinatal alcohol usage, which is characterized by neurodevelopmental dysfunction and growth retardation. Studies have mostly examined how alcohol affects the tissues of the brain. The effects of alcohol usage during pregnancy on the fetal liver are yet unknown at the molecular level. The aim of the study is to determine spectroscopic biomarkers referring to the results of prenatal exposure to alcohol in the liver of newborn mice. There were three main groups of samples: Negative control group, gavage control group (positive control), and group with gavage + alcohol. which is treated between postnatal days (PD) 3 and 20 with 3.0 g/kg body weight of ethanol in a liter of artificially enhanced milk (.02 ml/g). In accordance with that, there were three different groups of samples, for these groups, these three different groups of samples were measured using FTIR spectra, and in statistical analysis, these spectral data were evaluated. In the classification of spectral data, three main regions were significant: Fingerprint region (800 to 1800 cm-1), lipid region (3000 to 2800 cm-1) and water region and O-H stretch region (3000 to 3600 cm-1). For normalization, a standard normal variate (SNV) normalization technique was evaluated after the baseline correction. For statistical analysis, principal component analysis (PCA) was evaluated using R statistical language with FactoMineR package. According to the results of this study, it can be proposed that FTIR is an effective tool for development of chemometric markers in liver tissue, especially for the observation of the consequences of consuming alcohol on female rats. Possible chemometric biomarkers detected in this study are related to the lipids and found as follows: 2960 cm-1, 2873 cm-1, 1454 cm-1 and 1398 cm-1. Further studies can reveal the levels of alcohol consumption and detection of other markers.
Determination of the role of pyridostigmine treatment in myasthenia gravis disease at molecular level by infrared spectroscopy
Myasthenia gravis, one of the neuromuscular junction diseases, is a rare autoimmune disease with extensiveness of 15-20 per 100,000 people. Ptosis and skeletal muscle weakness are the most characteristic features of this antibody-mediated disease. Although skeletal and extraocular muscles are mostly affected in patients, violent involvement of respiratory muscles is observed in some of the patients. Due to the violent involvement of the muscles used in breathing, complications called myasthenic crisis, which can be fatal, develop. The illness may progress from ocular MG to generalized MG after at least two years. People with ocular symptoms may receive therapy with acetylcholinesterase inhibitors, called symptomatic therapy since ocular symptoms are characteristic signs of the disease. Pyridostigmine is the most commonly used medicine for this treatment. The quantity of acetylcholine is increased at the neuromuscular junction by inhibition of the enzyme acetylcholinesterase, which hydrolyzes acetylcholine. Thus, neuromuscular transmission is supported. In this thesis study, the role of pyridostigmine treatment in the pathogenesis of MG was investigated at the molecular level by infrared spectroscopy by comparing the serum of patients using and not using pyridostigmine and control. Our results revealed that the use of pyridostigmine reduced the elevated effect of MG on saturated lipid, DNA concentration, and protein phosphorylation and approaches the control values. These results clearly indicate that Pyridostigmine has a recovery impact against MG-induced alterations in serum biomolecules.
Protein birikimlerinin tespiti için fiber optik biyosensör geliştirilmesi
α-synuclein oligomers play a crucial role in the early diagnosis of Parkinson's disease (PD). In this study, a mercaptoundecanoic acid (MUA)-capped gold nanorod (GNR)-coated and chitosan (CH)-immobilized fiber optic probe has shown considerable sensitivity of its detection. The proposed U-shaped fiber optic biosensor based on localized surface plasmon resonance (LSPR) was applied to detect α-syn oligomer (OA) biomarker. By analyzing OA concentrations, the biosensor achieved a limit of detection of (LOD) 11 pM within the concentration range of 10-100 pM and the sensitivity value was found as 502.69 ∆λ/RIU. Upon analysis of the CV% (coefficient of variation) and accuracy/recovery values, it is revealed that the sensor successfully fulfilled the criteria for success, displaying accuracy/recovery values within the range of 80%-120% and CV% values below 20%. This sensor presents significant advantages, including high sensitivity, specificity, and ability to detect very low concentrations of OA. In conclusion, the suggested U-shaped fiber optic biosensor has the potential to be valuable in the early detection of PD from a clinical perspective.
Nanoparçacık temelli manyetik hipertermi cihazlarının tasarım ve optimizasyonu
Compared to their healthy counterparts, cancer cells are affected more adversely by higher temperatures which can be achieved with magnetic nanoparticle magnetic hyperthermia (MNP–MH) by elevating the temperature to 41 − 45 o C range. In MNP–MH the energy is transferred between an applied alternating magnetic field (AMF) and MNPs' magnetization. Accordingly, devices producing AMFs are designed around dedicated coils driven by RF amplifiers. Herein, new analytical coil performance criteria were conceived and used in assessing the performance of different coil geometries that were numerically simulated. Subsequently, three best performing geometries were physically implemented and experiments were realized using a novel placeholder grid for physical performance measurements and validating newly defined criteria. An economically viable RF amplifier was designed and built.