Simultaneous Purification of Human Interferon Alpha-2b and Serum Albumin Using Bioprivileged Fluorinated Ionic Liquid-Based Aqueous Biphasic Systems.

Interferon alpha-2b (IFN-α2b) is an essential cytokine widely used in the treatment of chronic hepatitis C and hairy cell leukemia, and serum albumin is the most abundant plasma protein with numerous physiological functions. Effective single-step aqueous biphasic system (ABS) extraction for the simultaneous purification of IFN-α2b and BSA (serum albumin protein) was developed in this work. Effects of the ionic liquid (IL)-based ABS functionalization, fluorinated ILs (FILs; [C​2C​1Im][C​4F​9SO​3] and [N​1112(OH)][C​4F​9SO​3]) vs. mere fluoro-containing IL ([C​4C​1Im][CF​3SO​3]), in combination with sucrose or [N​1112(OH)][H​2PO​4] (well-known globular protein stabilizers), or high-charge-density salt K​3PO​4 were investigated. The effects of phase pH, phase water content (%wt), phase composition (%wt), and phase volume ratio were investigated. The phase pH was found to have a significant effect on IFN-α2b and BSA partition. Experimental results show that simultaneous single-step purification was achieved with a high yield (extraction efficiency up to 100%) for both proteins and a purification factor of IFN-α2b high in the enriched IFN-α2b phase (up to 23.22) and low in the BSA-enriched phase (down to 0.00). SDS-PAGE analysis confirmed the purity of both recovered proteins. The stability and structure of IFN-α2b and BSA were preserved or even improved (FIL-rich phase) during the purification step, as evaluated by CD spectroscopy and DSC. Binding studies of IFN-α2b and BSA with the ABS phase-forming components were assessed by MST, showing the strong interaction between FILs aggregates and both proteins. In view of their biocompatibility, customizable properties, and selectivity, FIL-based ABSs are suggested as an improved purification step that could facilitate the development of biologics.

Ionogels Derived from Fluorinated Ionic Liquids to Enhance Aqueous Drug Solubility for Local Drug Administration.

Gelatin is a popular biopolymer for biomedical applications due to its harmless impact with a negligible inflammatory response in the host organism. Gelatin interacts with soluble molecules in aqueous media as ionic counterparts such as ionic liquids (ILs) to be used as cosolvents to generate the so-called Ionogels. The perfluorinated IL (FIL), 1-ethyl-3-methylpyridinium perfluorobutanesulfonate, has been selected as co-hydrosolvent for fish gelatin due to its low cytotoxicity and hydrophobicity aprotic polar structure to improve the drug aqueous solubility. A series of FIL/water emulsions with different FIL content and their corresponding shark gelatin/FIL Ionogel has been designed to enhance the drug solubility whilst retaining the mechanical structure and their nanostructure was probed by simultaneous SAXS/WAXS, FTIR and Raman spectroscopy, DSC and rheological experiments. Likewise, the FIL assisted the solubility of the antitumoural Doxorubicin whilst retaining the performing mechanical properties of the drug delivery system network for the drug storage as well as the local administration by a syringe. In addition, the different controlled release mechanisms of two different antitumoral such as Doxorubicin and Mithramycin from two different Ionogels formulations were compared to previous gelatin hydrogels which proved the key structure correlation required to attain specific therapeutic dosages.

Disclosing the Potential of Fluorinated Ionic Liquids as Interferon-Alpha 2b Delivery Systems.

Interferon-alpha 2b (IFN-α 2b) is a therapeutic protein used for the treatment of cancer, viral infections, and auto-immune diseases. Its application is hindered by a low bioavailability and instability in the bloodstream, and the search for new strategies for a target delivery and stabilization of IFN-α 2b to improve its therapeutic efficacy is crucial. Fluorinated ionic liquids (FILs) are promising biomaterials that: (i) can form self-assembled structures; (ii) have complete miscibility in water; and (iii) can be designed to have reduced toxicity. The influence of IFN-α 2b in the aggregation behaviour of FILs and the interactions between them were investigated through conductivity and surface tension measurements, and using electron microscopic and spectroscopy techniques to study FILs feasibility as an interferon-alpha 2b delivery system. The results show that the presence of IFN-α 2b influences the aggregation behaviour of FILs and that strong interaction between the two compounds occurs. The protein might not be fully encapsulated by FILs. However, the FIL can be tailored in the future to carry IFN-α 2b by the formation of a conjugate, which prevents the aggregation of this protein. This work constitutes a first step toward the design and development of FIL-based IFN-α 2b delivery systems.

Design of Ionic Liquids for Fluorinated Gas Absorption: COSMO-RS Selection and Solubility Experiments.

In recent years, the fight against climate change and the mitigation of the impact of fluorinated gases (F-gases) on the atmosphere is a global concern. Development of technologies that help to efficiently separate and recycle hydrofluorocarbons (HFCs) at the end of the refrigeration and air conditioning equipment life is a priority. The technological development is important to stimulate the F-gas capture, specifically difluoromethane (R-32) and 1,1,1,2-tetrafluoroethane (R-134a), due to their high global warming potential. In this work, the COSMO-RS method is used to analyze the solute-solvent interactions and to determine Henry's constants of R-32 and R-134a in more than 600 ionic liquids. The three most performant ionic liquids were selected on the basis of COSMO-RS calculations, and F-gas absorption equilibrium isotherms were measured using gravimetric and volumetric methods. Experimental results are in good agreement with COSMO-RS predictions, with the ionic liquid tributyl(ethyl)phosphonium diethyl phosphate, [P2444][C2C2PO4], being the salt presenting the highest absorption capacities in molar and mass units compared to salts previously tested. The other two ionic liquids selected, trihexyltetradecylphosphonium glycinate, [P66614][C2NO2], and trihexyl(tetradecyl)phosphonium 2-cyano-pyrrole, [P66614][CNPyr], may be competitive as far as their absorption capacities are concerned. Future works will be guided on evaluating the performance of these ionic liquids at an industrial scale by means of process simulations, in order to elucidate the role in process efficiency of other relevant absorbent properties such as viscosity, molar weight, or specific heat.

Integration of Stable Ionic Liquid-Based Nanofluids into Polymer Membranes. Part II: Gas Separation Properties toward Fluorinated Greenhouse Gases.

Membrane technology can play a very influential role in the separation of the constituents of HFC refrigerant gas mixtures, which usually exhibit azeotropic or near-azeotropic behavior, with the goal of promoting the reuse of value-added compounds in the manufacture of new low-global warming potential (GWP) refrigerant mixtures that abide by the current F-gases regulations. In this context, the selective recovery of difluorometane (R32, GWP = 677) from the commercial blend R410A (GWP = 1924), an equimass mixture of R32 and pentafluoroethane (R125, GWP = 3170), is sought. To that end, this work explores for the first time the separation performance of novel mixed-matrix membranes (MMMs) functionalized with ioNanofluids (IoNFs) consisting in a stable suspension of exfoliated graphene nanoplatelets (xGnP) into a fluorinated ionic liquid (FIL), 1-ethyl-3-methylpyridinium perfluorobutanesulfonate ([C2C1py][C4F9SO3]). The results show that the presence of IoNF in the MMMs significantly enhances gas permeation, yet at the expense of slightly decreasing the selectivity of the base polymer. The best results were obtained with the MMM containing 40 wt% IoNF, which led to an improved permeability of the gas of interest (PR32 = 496 barrer) with respect to that of the neat polymer (PR32= 279 barrer) with a mixed-gas separation factor of 3.0 at the highest feed R410A pressure tested. Overall, the newly fabricated IoNF-MMMs allowed the separation of the near-azeotropic R410A mixture to recover the low-GWP R32 gas, which is of great interest for the circular economy of the refrigeration sector.

Process Evaluation of Fluorinated Ionic Liquids as F-Gas Absorbents.

The environmental impact of fluorinated gases (F-gases) necessitates the development of green technologies to mitigate them. Fluorinated ionic liquids (FIL/ILs) emerged as an alternative absorbent due to their unique and exceptional properties. In this work, a COSMO-based/Aspen Plus methodology was used to evaluate the performance of FIL/ILs as absorbents in the process scale of two F-gases: 1,1,1,2-tetrafluoroethane (R-134a) and difluoromethane (R-32). Results of the absorption column in equilibrium mode revealed that the behavior of FIL/ILs is similar under the same conditions, reaching higher efficiencies in the case of absorbing R-134a at a high F-gas partial pressure. Rate-based calculations in packing column demonstrated a kinetic control with highly viscous FIL/ILs, revealing higher performance differences between FIL/IL absorbents. The regeneration stage was also evaluated in near-industrial conditions. Operating conditions of the absorption column were optimized with a column of height 10 m and diameter ranging from 1.1 to 1.2 m at 10 bar total pressure, reaching 90% F gas recovery with an L/G range of 6-10. Finally, preliminary economic analysis revealed operating costs to recover 90% of F-gas of 70 $/ton (R-134a) and 130 $/ton (R-32) with the FIL/IL that revealed the best behavior, 1-ethyl-3-methylimidazolium triflate.

Human cytotoxicity and octanol/water partition coefficients of fluorinated ionic liquids.

The use of fluorinated ionic liquids (FILs) as novel materials in biological and pharmaceutical applications is an emerging research field. The knowledge of their cytotoxicity and that of 1-octanol/water partition coefficients are essential to assess their environmental risks, to estimate their toxicity and activity, or the hydrophilic/lipophilic balance, as well as to explore their properties as solvents in extraction processes or for successful drug design. The study of the cytotoxicity in four different human cell lines and the experimental measurement of the partition coefficient between 1-octanol and water (Po/w), using the slow-stirring method, were carried out for several FILs. In both studies, the effect of the cation ([C2C1Im]+, [C2C1py]+, [C4C1pyr]+, [N1112(OH)]+, or [N4444]+), the cationic alkyl side-chain length ([CnC1Im]+, with n = 2, 6, 8 or 12), and the anionic fluorinated chain length/anionic fluorinated domain size ([C4F9SO3]¯, [C8F17SO3]¯, or [N(C4F9SO3)2]¯) were analysed. The results reveal that both toxicity and partition properties are mainly influenced by the size of the cationic hydrogenated alkyl side-chain and that of the anionic fluorinated domain. The intrinsic tuneability of the FILs allows for their selection according to the lipophilic or hydrophilic character of the target biological system under consideration. The toxicity studies corroborate the biocompatible nature of some FILs tested in this work. Along, for all the FILs under study Po/w < 1.00. Accordingly, a decadic logarithm of the bioconcentration factor in fish of 0.5 would be estimated, which is below the regulatory endpoint used by regulatory agencies.

Rationalizing the diverse solid-liquid equilibria of binary mixtures of benzene and its fluorinated derivatives.

The solid-liquid phase behavior of benzene plus hexafluorobenzene binary mixtures is characterized by a stable congruent-melting binary solid, (C(6)H(6)·C(6)F(6)). In this work, differential scanning calorimetry (DSC) was used to build, for the first time, the temperature-composition phase diagrams of ten other binary mixtures involving benzene and its fluorinated derivatives. Distinct types of solid-liquid equilibria were observed, namely those exhibiting the usual eutectic behavior associated with ideal or quasi-ideal solubility conditions, or, in other cases, systems with equimolar congruent-melting solids. Data have been interpreted and rationalized using a unifying framework that takes into account the molecular dipole and quadrupole moments of the two components of each binary system and the structural motifs associated with each type of crystal.