In vitro cytotoxicity assessment of monocationic and dicationic pyridinium-based ionic liquids on HeLa, MCF-7, BGM and EA.hy926 cell lines

Dicationic ionic liquids (ILs) generally possess higher thermal and electrochemical stability than the analogous monocationic ILs, which makes them more suitable for high-temperature applications as solvents for organic reactions, lubricants or stationary phase in gas chromatography. However, knowledge on dicationic IL cytotoxicity is still scarce. Here we explore the cytotoxicity of twelve mono- and dicationic pyridinium-based ILs on HeLa, MCF-7, BGM and EA.hy926 cells. The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, cell cycle arrest assays, apoptosis experiments and orange staining were carried out. The results showed that dicationic ILs are generally less cytotoxic than their monocationic counterparts. In monocationic ILs, cytotoxicity was stronger when they contain long alkyl chains, because of their higher lipophilicity. However, the full effect of the length of the linkage alkyl chain of dicationic ILs on cytotoxicity is not clear probably because the chain is “trapped” between both cationic moieties. IL cytotoxicity is highly dependent on the cell type, and HeLa cells exposed to [C12Pyr]Br die via apoptosis. The present study increases our knowledge of IL cytotoxicity on human and monkey cells and clarifies the cell death mechanism. The results suggest that dicationic ILs offer the potential to replace some monocationic ILs because of their lower cytotoxicity.This work was partially supported by the European Commission (FEDER/ERDF) and the Spanish MINECO (Ref. CTQ2017-87708-R) and the research support programme of the Seneca Foundation of Science and Technology of Murcia, Spain (Ref. 20977/PI/18). M. G. Montalbán acknowledges support from MINECO (Juan de la Cierva-Formación contract, Ref. FJCI-2016-28081), P. Licence acknowledges EPSRC and BBSRC for support (EP/S005080/1, EP/P013341/1, BB/L013940/1)

Green synthesis of cellulose Nanoparticles for their use in biomedicine

Recently, nanoscience has been developed as a new branch of science to obtain material at the nanometre scale. Cellulose is a polysaccharide whose molecular structure consists of D-glucopyranose units linked by β(1→4) glycosidic bonds that form a linear structure. The use of cellulose, a biodegradable and biocompatible biopolymer [1], for the synthesis of nanoparticles, together with a synthesis procedure with low energy demand and the use of ionic liquids as solvents for the biopolymer [2], meets both the requirements of nanomedicine and the principles of green chemical engineering. In this work, the synthesis of cellulose nanoparticles (CNPs) using the ionic liquid 1-ethyl-3-methylimidazolium acetate has been investigated and optimised to obtain nanoparticles with good capability for drug carrying. Two types of cellulose purchased from different suppliers were tested. Cell viability studies have been performed with a cancer cell line (HeLa) and with a healthy cell line (EA.hy926). To obtain the CNPs the experimental setup used was previously described by Fuster et al. [3] to obtain silk fibroin nanoparticles, with modifications as shown in Scheme 1.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Predicting Density and Refractive Index of Ionic Liquids

The determination of the physicochemical properties of ionic liquids (ILs), such as density and refractive index, is essential for the design of processes that involve ILs. Density has been widely studied in ILs because of its importance whereas refractive index has received less attention even though its determination is rapid, highly accurate and needs a small amount of sample in most techniques. Due to the large number of possible cation and anion combinations, it is not practical to use trial and error methods to find a suitable ionic liquid for a given function. It would be preferable to predict physical properties of ILs from their structure. We compile in this work different methods to predict density and refractive index of ILs from literature. Especially, we describe the method developed by the authors in a previous work for predicting density of ILs through their molecular volume. We also correlate our experimental measurements of density and refractive index of ILs in order to predict one of the parameters knowing the other one as a function of temperature. As the measurement of refractive index is very fast and needs only a drop of the ionic liquid, this is also a very useful approach

Nanoparticles as Drug Delivery Systems

This chapter presents a review on the design of nanoparticles which have been proposed as drug delivery systems in biomedicine. It will begin with a brief historical review of nanotechnology including the most common types of nanoparticles (metal nanoparticles, liposomes, nanocrystals and polymeric nanoparticles) and their advantages as drug delivery systems. These advantages include the mechanism of increased penetration and retention, the transport of insoluble drugs and the controlled release. Next, the nanoparticle design principles and the routes of administration of nanoparticles (parental, oral, pulmonary and transdermal) are discussed. Different routes of elimination of nanoparticles (renal and hepatic) are also analyzed

Silk Fibroin Nanoparticles: Synthesis and Applications as Drug Nanocarriers

The use of nanoparticles in biomedical fields is a very promising scientific area and has aroused the interest of researchers in the search for new biodegradable, biocompatible and non-toxic materials. This chapter is based on the features of the biopolymer silk fibroin and its applications in nanomedicine. Silk fibroin, obtained from the Bombyx mori silkworm, is a natural polymeric biomaterial whose main features are its amphiphilic chemistry, biocompatibility, biodegradability, excellent mechanical properties in various material formats, and processing flexibility. All of these properties make silk fibroin a useful candidate to act as nanocarrier. In this chapter, the structure of silk fibroin, its biocompatibility and degradability are reviewed. In addition, an intensive review on the silk fibroin nanoparticle synthesis methods is also presented. Finally, the application of the silk fibroin nanoparticles for drug delivery acting as nanocarriers is detailed

Effect of Degumming in the Characteristics of Silk Fibroin Nanoparticles

Several studies have stated that the process used for sericin removal, or degumming, from silk cocoons has a strong impact on the silk fibroin integrity and consequently in their mechanical or biochemical properties after processing it into several biomaterials (e.g., fibers, films or scaffolds) but still, there is a lack of information of the impact on the features of silk nanoparticles. In this work, silk cocoons were degummed following four standard methods: autoclaving, short alkaline (Na2CO3) boiling, long alkaline (Na2CO3) boiling, and ultrasounds. The resultant silk fibroin fibers were dissolved in the ionic liquid 1-ethyl-3-methylimidazolium acetate and used for nanoparticle synthesis by rapid desolvation in polar organic solvents. The relative efficiencies of the degumming processes and the integrity of the resulting fibroin fibers obtained were analyzed by mass loss, optical microscopy, thermogravimetric analysis, infrared spectroscopy, and SDS-PAGE. Particle sizes and morphology were analyzed by Dynamic Light Scattering and Field Emission Scanning Electronic Microscopy. The results showed that the different treatments had a remarkable impact on the integrity of the silk fibroin chains, as confirmed by gel electrophoresis, which can be correlated with particle mean size and size distribution changes. The smallest nanoparticles (156 ± 3 nm) and the most negative Z potential (−30.2 ± 1.8 mV) were obtained with the combination of long treatment (2 h) of boiling in alkaline solution (Na2CO3 0.02 eq/L). The study confirms that parameters of the process, such as the composition of the solution and time of the degumming step, must be controlled in order to reach an optimum reproducibility of the nanoparticle production.This work has been partially supported (80%) by the European Commission ERDF/FEDER Operational Programme 'Murcia' CCI N° 2007ES161PO001 (Project No. 14-20/20), and the Spanish MINECO (Ref. CTQ2017-87708-R) and the programme of support to the research of the Seneca Foundation of Science and Technology of Murcia, Spain (Ref. 20977/PI/18). A.A.L.-P.’s research contract was partially supported (80%) by the ERDF/FEDER Operational Programme 'Murcia' CCI N° 2007ES161PO001 (Project No. 14-20/20),. M.G. Montalbán’s research contract is funded by the Spanish MINECO (Juan de la Cierva-Formación contract, Ref. FJCI-2016-28081). S.D.A.-C.’s research contract is funded by the program INIA-CCAA (DOC INIA 2015), announced by the National Institute for Agricultural and Food Research and Technology (INIA) and supported by the Spanish State Research Agency (AEI) under the Spanish Ministry of Economy, Industry and Competitiveness

Biopolymeric Nanoparticle Synthesis in Ionic Liquids

Recently, much research has focused on the use of biopolymers, which are regarded as biodegradable, natural, and environmentally friendly materials. In this context, biopolymeric nanoparticles have attracted great attention in the last few years due to their multiple applications especially in the field of biomedicine. Ionic liquids have emerged as promising solvents for use in a wide variety of chemical and biochemical processes for their extraordinary properties, which include negligible vapor pressure, high thermal and chemical stability, lower toxicity than conventional organic solvents, and the possibility of tuning their physical–chemical properties by choosing the appropriate cation and anion. We here review the published works concerning the synthesis of biopolymeric nanoparticles using ionic liquids, such as trimethylsilyl cellulose or silk fibroin. We also mention our recent studies describing how high-power ultrasounds are capable of enhancing the dissolution process of silk proteins in ionic liquids and how silk fibroin nanoparticles can be directly obtained from the silk fibroin/ionic liquid solution by rapid desolvation in polar organic solvents. As an example, their potential biomedical application of curcumin-loaded silk fibroin nanoparticles for cancer therapy is also discussed

Revealing the Influence of the Degumming Process in the Properties of Silk Fibroin Nanoparticles

Several studies have stated that the process used for sericin removal, or degumming, from silk cocoons has a strong impact in the silk fibroin integrity and consequently in their mechanical or biochemical properties after processing it into several biomaterials (e.g. fibers, films or scaffolds) but still, there is a lack of information of the impact on the features of silk nanoparticles. In this work, silk cocoons were degummed following four standard methods: autoclaving, short alkaline (Na2CO3) boiling, long alkaline (Na2CO3) boiling and ultrasounds. The resultant silk fibroin fibers were dissolved in the ionic liquid 1-ethyl-3-methylimidazolium acetate and used for nanoparticle synthesis by rapid desolvation in polar organic solvents. The relative efficiencies of the degumming processes and the integrity of the resulting fibroin fibers obtained were analyzed by mass loss, optical microscopy, thermogravimetric analysis, infrared spectroscopy and SDS-PAGE. Particle sizes and morphology were analyzed by Dynamic Light Scattering and Field Emission Scanning Electronic Microscopy. The results showed that the different treatments had a remarkable impact on the integrity of the silk fibroin chains, as confirmed by gel electrophoresis, which can be correlated with particle mean size and size distribution changes. The smallest nanoparticles (156 ± 3 nm) and the most negative Z potential (−30.2 ± 1.8 mV) were obtained with the combination of long treatment (2 h) of boiling in alkaline solution (Na2CO3 0.02 eq/L). The study confirms that parameters of the process, such as composition of the solution and time of the degumming step, must be controlled in order to reach an optimum reproducibility of the nanoparticle production.This work has been partially supported (80%) from the European Commission ERDF/FEDER Operational Programme 'Murcia' CCI N° 2007ES161PO001 (Project No. 14-20/20), and the Spanish MINECO (Ref. CTQ2017-87708-R) and the programme of support to the research of the Seneca Foundation of Science and Technology of Murcia, Spain (Ref. 20977/PI/18).A.A. Lozano-Pérez’s research contract was partially supported (80%) by the ERDF/FEDER Operational Programme 'Murcia' CCI N° 2007ES161PO001 (Project No. 14-20/20),. M.G. Montalbán’s research contract is funded by the Spanish MINECO (Juan de la Cierva-Formación contract, Ref. FJCI-2016-28081). S.D. Aznar-Cervantes’s research contract is funded by the program INIA-CCAA (DOC INIA 2015), announced by the National Institute for Agricultural and Food Research and Technology (INIA) and supported by The Spanish State Research Agency (AEI) under the Spanish Ministry of Economy, Industry and Competitiveness

Modelos de simulación de un reactor de pirólisis de nafta . Su ajuste experimental / María Gloria Villora Cano ; Dirección Antonio Bódalo Santoyo y Antonio López Cabanes.

Tesis - Universidad de Murcia.Consulte la tesis en: BCA. GENERAL. ARCHIVO UNIVERSITARIO. TM 3309

Supercritical Fluids: Properties and Applications

Currently, both humanity and the whole planet are living in a critical time, which leads us to look for more sustainable formulas to interact with the environment. One of the important changes in the design and operation of chemical processes is the search for environmentally friendly technologies. Many industrial processes are carried out under severe conditions or with reactants that involve the use of strong acids, toxic metal catalysts, organic solvents, and processes at high temperatures and/or pressures. Supercritical fluids (SCFs) and, among these, supercritical carbon dioxide (scCO2), have been revealed as promising environmentally friendly solvents, energy-efficient, selective, and capable of reducing waste, constituting an alternative to conventional organic solvents. The use of SCF, such as solvents and reaction media, makes it possible to work in less severe and more environmentally friendly conditions, even considerably increasing the efficiency of the processes. This chapter provides a brief review of the most important properties of SCF, with special emphasis on scCO2, as well as some of the most important applications