Ispitivanje mogućnosti korišćenja nanočestica TiO2 kao nosača za ciljanu i kontrolisanu dostavu lekova na bazi kompleksa prelaznih metala

Sinteza i primena kompleksa prelaznih metala u lečenju kancera je predmet istraživanja velikog broja naučnika. Potreba za razvojem novih citostatika proizilazi iz želje da se prevaziđu nedostaci već postojećih, kao što su rezistencija, toksičnost i uzak terapeutski opseg (aktivnost protiv malog broja tipova tumora). Tako se pored kompleksa platine, i dalje najčešće korišćenih citostatika u kliničkoj praksi, razvila čitava serija novih kompleksa redizajniranjem već postojećih izmenom liganada i/ili izmenom centralnog metalnog jona. Posebno su se izdvojili kompleksi rutenijuma zbog manje toksičnosti, aktivnosti na metastazama i tumorima na kojima su dotadašnji citostatici bili neaktivni, a neki od njih su pokazali aktivnost tek kada se ozrače svetlošću odgovarajuće talasne dužine i potencijal za primenu u fotodinamičkoj terapiji. Uprkos razvoju novih generacija citostatika s poboljšanim karakteristikama, kao problem ostaje kontrola postizanja maksimalne koncentracije leka u tumorskom tkivu. Na putu do ciljnog, tumorskog tkiva i ciljnih biomolekula, lek interaguje i s brojnim drugim biomolekulima što za posledicu može imati toksičnost, pojavu rezistencije, inaktivaciju leka i smanjenje njegove efektivne koncentracije na željenom mestu dejstva. Potreba za prevazilaženjem ovog problema dovela je do brzog razvoja nosača za lekove. Njihova uloga je da vežu ili inkapsuliraju lek, nose ga do tumorskog tkiva sprečavajući njegovu interakciju s okolnim biomolekulima i zatim ga otpuste, aktivnim ili pasivnim mehanizmom, u ciljnom tumorskom tkivu. Cilj upotrebe ovakvih sistema je smanjenje štetnog dejstva leka na zdravo tkivo, mogućnost kontrole doziranja leka tj. postizanje njegove optimalne koncentracije u tumorskom tkivu, a samim tim i postizanje veće efikasnosti terapije. Nosači koji se testiraju za mogućnost primene u kontrolisanoj i ciljanoj dostavi medikamenata su uglavnom na bazi organskih i neorganskih nanomaterijala, međutim mali broj njih je u kliničkoj upotrebi (lipozomi i polimerni nanomaterijali). U fazi ispitivanja su mnogobrojni nosači koji reaguju na stimulanse kao što su pH sredine, ultrazvuk, temperatura i svetlost. U novijim istraživanjima veliku pažnju kao nosači za lekove zauzimaju nanočestice TiO2 zbog svoje biokompatibilnosti, fotoaktivnosti, dostupnosti i mogućnosti modifikacije površine.A significantly rising interest in the design and use of metal complexes for cancer treatment is currently observed in the area of scientific inquiry. There has been a growing demand for development and improvement of metal-based compounds used in routine clinical practice in order to overcome disadvantages and limitations such as resistance, toxicity and narrow spectrum of activity (activity against a small number of tumor types). Beside platinum complexes, the leading agents in clinical use, many more metal-based compounds have been synthesized by redesigning the existing chemical structure through ligand substitution and/or central metal ion switching. Among them ruthenium complexes have been investigated as one of the most promising candidates because they shown less toxicity, significant activity against cancer metastases, and activity on tumors that were resistant to a variety of standard chemotherapeutic agents. Moreover, some of them are light sensitive drugs i.e. their functions is triggered once they are activated by light of a specific wavelength which make them promising candidates for photodynamic therapy. Despite fast development of new generation of cytostatics with better characteristics, there are still areas where substantial improvements need to be made. One such area is achievement of a maximum concentration of the drug on tumor site. Once the drug enters the systemic circulation, it could face a number of challenges. Drug could react with nontarget biomolecules on its way to target biomolecules in tumor tissue which could cause severe side effects such as toxicity, resistance, inactivation of the drug and reduction of its effective concentration at the target tumor site. One way to solve these problems is the development of drug delivery systems which consist of drug and drug carrier. Role of drug carriers is to bind or encapsulate the drug, prevent its interaction with non-target biomolecules, to carry the drug to the target tumor tissue and then release it with active or passive mechanism. The main advantages of using drug delivery systems are reduction of side effects of drug onto the healthy tissue, dosage control, optimal concentration of drug in the tumor tissue, and more effective treatment which could improve outcome of therapy. Many organic and inorganic nanoparticles have been tested as drug carriers, but just few of them are in clinical use (liposomes and polymers). In recent years smart nanosystems for targeted drug delivery that respond to various stimuli including pH, ultrasound, temperature and light irradiation are in the center of many investigations

Senzor na bazi mezoporozne silike za kolorimetrijsko određivanje boje Basic Yellow 28 u vodenim rastvorima

The textile industry is one of the largest water-consuming industries in the world. The wastewater generated by the textile industry is a major source of pollution, containing mostly dyes, but also detergents, and heavy metals. Since dyes can have a negative impact on the environment, human and aquatic life, it is really important to find proper solutions for removal of these pollutants from wastewater. In addition, special attention is given to the discovery of new and fast "in situ" methods for identification and quantification of pollutants from wastewater. In this paper, SBA-15, mesoporous silica material, was used as sorbent for removal of Basic Yellow 28 from aqueous solutions. In addition, colored SBA-15 after sorption process was subjected to image analysis, to evaluate if it was possible to quantify sorbed dye on sorbent based on intensity of SBA-15 coloration. The obtained results revealed that SBA-15 could remove 99% of dye within 5 min. The highest efficiency of dye removal was at pH8, using 200 mg of sorbent. According to the Langmuir isotherm model, the theoretical maximum sorption capacity was 909 mg/g. Image-Pro software confirmed that it would be possible to quantify sorbed dye onto SBA-15 with accuracy of 0.98. Overall, SBA-15 demonstrated to be efficient sorbent in removal of Basic Yellow 28 from water, but also to be potential carrier as a sensor for detection of colored pollutants in water.Tekstilna industrija je jedna od najvećih potrošača vode u odnosu na druge industrijske grane. Otpadne vode iz tekstilne industrije su jedan od glavnih izvora zagađenja i uglavnom sadrže boje, ali takođe i deterdžente i teške metale. Pošto boje mogu imati negativan uticaj na životnu sredinu, ljude i vodeni svet, važno je pronaći odgovarajuća rešenja za uklanjanje ovih zagađivača iz otpadnih voda. Pored toga, posebna pažnja je posvećena otkrivanju novih i brzih „in situ” metoda za identifikaciju i kvantifikaciju zagađivača iz otpadnih voda. U ovom radu kao sorbent za uklanjanje Basic Yellow 28 boje iz vodenih rastvora korišćen je SBA-15, mezoporozni silika materijal. Pored toga, obojeni SBA-15 nakon procesa sorpcije podvrgnuti su analizi slike, kako bi se procenilo da li je moguće kvantifikovati sorbovanu boju na sorbentu na osnovu intenziteta obojenosti SBA-15. Dobijeni rezultati su pokazali da SBA-15 može ukloniti 99% boje u roku od 5 minuta. Najveća efikasnost uklanjanja boje bila je pri pH 8, korišćenjem 200 mg sorbenta. Prema Langmuirovom modelu, teoretski maksimalni kapacitet sorpcije bio je 909 mg/g. Softver Image-Pro je potvrdio da je moguće kvantifikovati boju na SBA-15 sa tačnošću od 0,98. SBA-15 se pokazao kao efikasan sorbent u uklanjanju Basic Yellow 28 boje iz vode, ali i kao potencijalni senzor za detekciju obojenih zagađivača u vodi

Characterization of soil for production of cabbage

This paper reviews a part of analyses of soils used for production of cabbage in the production fields around the village of Futog near Novi Sad. The analyzed soils are heterogeneous but invariably of light mechanical composition. The topsoils have unfavorable water/air properties, low total porosity (from 36.82% to 42.70%) and medium water permeability (from 10-3 to 10-5 cm/s). Low humus content (from 1.62% to 2.17%), highly variable phosphorus content (from 6.5 to 107.0 mg 100-1 g of soil) and medium to high potassium content (from 15.5 to 70.0 mg 100-1 g of soil) are common properties of the surface soil layers of all soil profiles studied. Based on the proportion and biodiversity of the studied groups of microorganisms and dehydrogenase activity, it has been concluded that the analyzed soils have a high biological value

DETERMINATION OF CONTENT AND ANTIOXIDANT CAPACITY OF NATURAL FOOD COLORS E160A AND E160D IN KETCHUP

After potato, tomato (Solanum lycopersicum) is the world’s second-largest vegetable crop. More than 80% of tomato consumption comes from processed products such as ketchup, tomato juice, pickled tomatoes, sauces, paste, purée. Samples of mild ketchup from two different manufacturers (A and B) were selected for the analysis of the content of natural food colors E160a and E160d. Using a UV-Vis spectrophotometric method and Lambert-Beer law, a system of two linear equations with two unknowns was set up, which was used to determine the concentrations of colors E160a and E160d. The antioxidant capacity of the two selected samples was determined using the DPPH assay. The obtained results indicated that the content of colors E160a and E160d was higher in the sample of ketchup B. Also, the DPPH assay showed that the sample of ketchup B had a higher antioxidant capacity

Cancer cell death induced by ruthenium complexes

Summary. Cancer is a complex and often fatal disease characterized by uncontrolled cell division. The most commonly used chemotherapeutics target rapidly dividing cancer cells but, at the same time, damage healthy dividing cells. New metal-based complexes, such as ruthenium complexes, that possess cytotoxic properties, have been developed to overcome these challenges. Ruthenium complexes achieve their antitumor effect mainly by inducing apoptosis. In recent years, induction of other types of cell death, such as ferroptosis and autophagy, was also reported. The dual role of autophagy in cancer cells is a major challenge for the application of metallocomplexes in cancer treatment, either as inducers or inhibitors of autophagy. Also, the effect of ruthenium complexes on other cellular processes such as cell cycle, cell migration, and adhesion are promising approaches in cancer treatment. Our results indicated a significant influence of Ru(II) complexes on these processes in melanoma, cervical and pancreatic cancer. The aim of this review is to summarize the latest data on the effect of ruthenium complexes on different types of cell death

The interaction between variously shaped TiO2 nanoparticles with UV laser determines the quality of the mass spectra of carbohydrates

The important factor that determines the process of the laser-induced desorption and ionization of molecules for the mass spectrometric analysis is the interaction between the laser light and the substrate. It is of importance that substrate efficiently absorbs laser energy, which will be further rapidly transferred to the analyte. The overall goal in this process is to obtain good quality mass spectrum with low degree of fragmentation. Whereas the application of organic matrices instead of substrates results in the numerous undesired polymerization reactions, which complicate the spectra, and in some cases, even prevent the detection of the ions of interests, nanoparticles as substrates are convenient due to a lower number of background signals and low onset of fragmentation reactions in the gas phase. Titanium dioxide (TiO2) is semiconductor-based and widely used substrate for laser desorption and ionization ((SA)LDI), and when it is in the excited state it transfers an electron or energy into the ground state molecule. This process is called sensitized photoreaction [1]. The desorption/ionization processes on TiO2 nanoparticles are related to the physical properties of the substrate such as ability to absorb and dissipate energy from the irradiating laser light source [2]. TiO2 has a large band gap (bulk anatase: 3.2 eV), and can therefore be used as a SALDI matrix with the N2 laser (337 nm) [3]. The aim of our study is to investigate the influence, which the interaction of the UV laser with TiO2 nanoparticles of various shapes and size has on the quality of the mass spectra of carbohydrates: D-(+)-glucose, D-(+)-maltose, raffinose, arabinose, β-ciclodextrine, substances which are otherwise difficult for mass spectrometric analysis. For this purpose, we used small, nearly spherically shaped colloidal TiO2 nanoparticles (average diameter ~ 5 nm), prolate nanospheroids (length: 40–50 nm, the lateral dimension: 14–16 nm) and nanotubes (length: 100-150 nm, average diameter 11 nm). For comparison, the spectra are acquired also with traditionally used organic matrices. The spectra of carbohydrates with organic matrices are overloaded with matrix signals, in which case the signals arising from the analyte of interest are suppressed, or it is possible to detect only adducts with matrix. Laser-induced ionization on nanostructures offers alternative ionization pathways through the formation of Na+ and K+ adducts with appreciable yield [4]. TiO2 nanotubes showed extraordinary properties for detection of carbohydrates. Arabinose was detectable only with TiO2, and D-(+)-glucose and D-(+)-maltose were detected in negative ion mode, which was not the case with other organic matrices and substrates. Not only the highest intensities of mass peaks but also the smallest coefficient of variation was achieved with TiO2 nanotubes. Taken toghether, TiO2 nanotubes, due to their size and the shape, have the most suitable physical properties for the substrate in the SALDI technique. The laser intensity was kept as low as possible in order to prevent fragmentaion. Higher laser intensity is required for the process of desorption/ionization when TiO2 NPs are used (2400 i.u.), but for TiO2 PNSs and TiO2 nanotubes were lower and nearly the same 1950 and 2000 i.u., respectively. In conclusion, larger, tube-shaped TiO2 substrates more efficiently absorb the laser energy and transfer it to the carbohydrates, enabling their desorption/ionization and preventing their fragmentation.V International School and Conference on Photonics and COST actions: MP1204, BM1205 and MP1205 and the Second international workshop "Control of light and matter waves propagation and localization in photonic lattices" : PHOTONICA2015 : book of abstracts; August 24-28, 2015; Belgrad

Soil quality for sustainable production of sunflower and soybean

The production plots of three large sunflower and soybean growers in the Vojvodina Province (AIC "Bečej" in Bečej, "Agrodunav" in Karavukovo and "Graničar" in Adaševci) were analyzed in 2002 and 2003, as a part of the project titled "Soil characterization and land management for production of highvalue food from sunflower and soybean". Soil samples taken from profiles (24) and topsoil (55) were analyzed for more than 30 parameters, i.e. physical properties, main chemical properties, total contents of microelements and heavy metals, contents of polycyclic aromatic hydrocarbons (PAHs) and the activity concentration of radionuclides

Uticaj organske i konvencionalne proizvodnje na sadržaj organske materije u černozemu

In this paper, in on-farm research, the effects of organic and conventional production systems on content of organic matter in Chernozem were compared. Preliminary results indicate that there were significant differences between some locations. Significantly lower organic matter content was measured on location Ljutovo (2,49%), compared to Čenej (3,17%) and Bačko Gradište (3,14%). In organic production systems which include manure application content of organic matter is equal or higher compared to conventional production systems. The lowest organic matter content was measured in crop rotations which include summer barley, regardless production systems or location.U radu su istraživanjima na farmi upoređeni uticaji organske i konvencionalne proizvodnje na sadržaj organske materije (OM) u černozemu. Preliminarni rezultati ukazuju da postoje značajne razlike između pojedinih lokaliteta. Znatno niži sadržaj organske materije izmeren je na lokalitetu Ljutovo (2,49%) u odnosu na lokalitete Čenej (3,17%) i Bačko Gradište (3,14%). U sistemima organske proizvodnje koji uključuju stajnjak, sadržaj organske materije u zemljištu je jednak ili visi u odnosu na sisteme konvencionalne proizvodnje. Najniži sadržaj organske materije izmeren je na plodoredima sa jarim ječmom, bez obzira na sistem proizvodnje i lokalitet

Outer membrane vesicles of plant beneficial bacterial strain Paraburkholderia phytofirmans PsJN make a contact with Arabidopsis thaliana roots

Extracellular vesicles (EVs) are recognized as important mediators of intercellular communication in both eukaryotes and prokaryotes. These lipid membrane – coated spherical nanoparticles carry proteins, nucleic acids and other cellular products, and facilitate exchange of these biomolecules among cells within an organism, but also between cells of different organisms, belonging to different species and even kingdoms. Outer membrane vesicles (OMVs), EVs produced by Gram-negative bacteria, are a significant mediator of microbial communication, involved in biofilm formation, virulence, and modulation of host immunity. OMVs of both pathogenic and plant beneficial bacteria have been shown to elicit plant immune responses. Investigations on the modes of OMV-plant cells interactions are still in their infancy, but gain rising attention. Aiming to monitor the interaction between OMVs of Paraburkholderia phytofirmans PsJN, a plant growth promoting bacteria, and Arabidopsis thaliana roots, we isolated OMVs from bacterial culture in mineral medium, using an ion-exchange chromatography system. Isolated OMVs were labeled with lipid binding fluorescent dye Vybrant™ DiD and unbound dye was removed by washing vesicles on ultrafiltration columns. The same dye concentration in phosphate buffer saline, equivalently washed, was used as a control. A. thaliana roots, grown on Murashige and Skoog medium, were incubated with DiD-OMVs or control dye/buffer mixture, washed and observed under confocal laser scanning microscope. Red signals were observed in root hairs and epidermis in DiD-OMV treated plants, while in control-treated roots the same signals were missing. The results indicate direct contact of bacterial vesicles with epidermis and root hairs, which are indispensable for nutrient acquisition and plant-microbe interactions in rhizosphere. Further investigation will address the questions of the nature of OMVplant cell interaction, including potential delivery of OMVs cargo into host plant cells. Considering that OMVs are increasingly recognized as promising tools in biomedicine, exploring their potential for agronomical applications would be highly appreciated.Book of abstract: ICGEB WORKSHOP; Trends in microbial solutions for sustainable agriculture, 13 – 15 September 2023. Belgrade, Serbi