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Poly(3-hydroxybutyrate) (PHB)-based films containing Poly(ethylene glycol) (PEG), esterified sodium alginate (ALG-e) and polymeric additives loaded with Ag nanoparticles (AgNPs) were obtained by a conventional casting method. AgNPs were produced in aqueous suspension and added to polymeric gels using a phase exchange technique. Composite formation was confirmed by finding the Ag peak in the XRD pattern of PHB. The morphological analysis showed that the inclusion of PEG polymer caused the occurrence of pores over the film surface, which were overshadowed by the addition of ALG-e polymer. The PHB functional groups were dominating the FTIR spectrum, whose bands associated with the crystalline and amorphous regions increased after the addition of PEG and ALG-e polymers. Thermal analysis of the films revealed a decrease in the degradation temperature of PHB containing PEG/AgNPs and PEG/ALG-e/AgNPs, suggesting a catalytic effect. The PHB/PEG/ALG-e/AgNPs film combined the best properties of water vapor permeability and hydrophilicity of the different polymers used. All samples showed good antimicrobial activity in vitro, with the greater inhibitory halo observed for the PEG/PEG/AgNPs against Gram positive S. aureus microorganisms. Thus, the PHB/PEG/ALG-e/AgNPs composite demonstrated here is a promising candidate for skin wound healing treatment.

Produced water, a mixture of inorganic and organic components, comprises the largest effluent stream from oil and gas activities. The removal of contaminants from this wastewater is receiving special attention of the researchers since most of them are persistent and difficult to remove with simple techniques. Several technologies from conventional to advanced oxidation processes have been employed to treat produced water. However, the achievement of greater efficiency may be conditioned to a combination of different wastewater treatment techniques. Hereupon, the present paper discusses three important aspects regarding produced water treatment: analytical methods used for characterization, relevant aspects regarding photochemical systems used for advanced oxidation processes, and combined techniques for treating oil field wastewaters. Analytical methods employed for the quantification of the main species contained in produced water are presented for a proper characterization. Photochemical aspects of the reaction systems such as operating conditions, types of irradiation sources, and technical details of reactors are also addressed. Finally, research papers concerning combined treatment techniques are discussed focusing on the essential contributions. Thus, this manuscript aims to assist in the development of novel techniques and the improvement of produced water treatment to obtain a high-quality treated effluent and reduce environmental impacts.

This paper proposes a novel approach to the development of magnetic nanoparticles (MNPs) for drug delivery systems. The nanocarriers are made from FeFe2O4 and CoFe2O4 MNPs that were synthesized by combustion, coated with silica derivatives, and then conjugated to ciprofloxacin. The drug release tests were performed into simulated body fluid consisted of ciprofloxacin adsorbed onto MNPs composites with various mass ratios of hydroxyapatite:FeFe2O4 (M) and hydroxyapatite:CoFe2O4 (C), evaluated by pharmacokinetic models, and regression analysis. The MNPs were characterized by morphological and structural characterizations. Drug release was measured with a discontinuous method (paddle apparatus) and with a continuous method simulating a blood vessel. XRD and FTIR showed that all of the MNPs were successfully synthesized, coated, and drug conjugated. VSM exhibited superparamagnetic characteristics, with saturation magnetization varying between 9.74 and 32.90 emu/g and 9.65–30.00 emu/g for FeFe2O4 and CoFe2O4, respectively, as a function of the MNPs mass ratio on the nanocarrier. The discontinuous method showed drug release over 80% (FeFe2O4), while the CoFe2O4-based achieved over 40%, which indicates that the incorporation of hydroxyapatite favors the carrying of ciprofloxacin. The continuous method showed a drug release under 14% and 14.5% for the FeFe2O4 and CoFe2O4 based nanocarriers respectively, and this reduction of the desorbed drug compared to the discontinuous method may have occurred due to the action of the applied magnetic field. The mathematical model provided the release speed and time to reach the maximum fraction desorbed (

Human milk fat (HMF) triacylglycerols (TAGs) mainly contain palmitic acid esterified at the sn-2 position while oleic and other unsaturated fatty acids are located at positions sn-1,3. This study aimed at the production of HMF substitutes (HMFS) by lipase-catalyzed acidolysis of tripalmitin with oleic acid, in a solvent-free medium. Burkholderia cepacia lipase (BCL) was immobilized in silica (prepared with protic or aprotic ionic liquids) by covalent binding or encapsulation and used as biocatalyst. The supports and immobilized biocatalysts were characterized by FTIR, TGA, and SEM. Molecular docking analysis showed that BCL preferentially attacks oleic acid rather than tripalmitin, due to the lower free energy of hydrophobic binding with this acid (−6.5 kcal·mol−1) than with tripalmitin (5.4 kcal·mol−1). Therefore, the tripalmitin attack by BCL and subsequent HMFS production only occurs after the binding to most of the oleic acid molecules. The highest acidolysis activity was obtained with BCL immobilized by covalent binding in prepared silica with aprotic ionic liquid. A central composite rotatable design, as a function of temperature (58–72 °C) and oleic acid/tripalmitin molar ratio (MR = 2:1–6.8:1), was performed for acidolysis optimization. Under optimized conditions (58 °C and MR = 4:1 or 60 °C and MR = 2:1), the oleic acid incorporation of 28 mol.% was achieved after 48 h.

Aqueous two-phase systems (ATPS) consisting of potassium phosphate salt + alcohol or polyethylene glycol were investigated to extract gallic acid. The partitioning process was studied using purity gallic acid (GA). The constituents either promote the partition process of GA to bottom or top phase, leading to the creation of versatile systems. The salt acts as a drive force of process because it influences the value of phase pH, and consequently the deprotonation of biomolecule and its partition. The results using GA from guava are in close agreement with the model systems, validating the experimental data and supporting their applicability in real systems.

Extraction of rutin from acerola waste was investigated using alcohol-salt-based aqueous two-phase systems (ATPS). Initially, the partitioning was studied using model systems with pure and commercial rutin. The impact of the ATPS constituents and composition, initial amount of rutin, temperature and addition of electrolytes was evaluated. Rutin can be recovered either in the alcohol-or-salt-rich phase depending on the salt used. To validate the optimization process, rutin extraction from acerola waste was carried out further. The results obtained with the real samples are in close agreement with the model systems and validate the optimization tests and support their applicability in bioresource-related processes.

A single-step selective separation of two food additives was investigated using alcohol-salt aqueous two-phase systems (ATPS). The selective partitioning of two of the most used additives from a processed food waste material, vanillin and l-ascorbic acid, was successfully accomplished. The results obtained prove that alcohol-salt ATPS can be easily applied as cheaper processes for the selective recovery of valuable chemical products from food wastes and other sources. As a first approach, the phase diagrams of ATPS composed of different alcohol+inorganic salt+water were determined at 298 (± 1)K and atmospheric pressure. The influence of methanol, ethanol, 1-propanol, and 2-propanol and K(3)PO(4), K(2)HPO(4) or KH(2)PO(4)/K(2)HPO(4) in the design of the phase diagrams was addressed. After the evaluation of the phase diagrams behaviour, the influence of the phase forming constituents was assessed towards the partition coefficients and recovery percentages of vanillin and l-ascorbic acid among the coexisting phases. Both model systems and real processed food waste materials were employed. Using these ATPS as partitioning systems it is possible to recover and separate vanillin, which migrates for the alcohol-rich phase, from l-ascorbic acid, which preferentially partitions for the salt-rich phase. published