Search

This work aimed to develop gastro-resistant capsules, based on alginate (Alg), as an oral delivery system for enhanced bioavailability of proteins. Bovine Serum Albumin (BSA), selected as a model protein, has been encapsulated inside calcium alginate capsules, which have been coated with a thin layer of chitosan (CHT) to improve its robustness and delivery profile. BSA and sodium alginate aqueous mixtures were characterized by optical microscopy and dynamic light scattering, suggesting that BSA and sodium alginate form water-in-water coacervate droplets by ionic complexation. Encapsulation of BSA-Alg colloidal dispersions was performed by introducing the BSA-Alg mixtures in CaCl2 solutions. Thus, calcium alginate capsules were formed, which were subsequently coated with CHT. Encapsulation of BSA achieved ≈99 % efficiency, the water content of capsules was ≈95 wt % and the amount of chitosan coating in wet capsules was <0.032 wt %. The stability of the capsules and the release of BSA were studied by several in vitro techniques, in simulated gastric and intestinal fluids. The addition of CHT as a coating material greatly improved the performance of the capsules, compared to that of capsules without CHT. The results of calcium alginate-chitosan capsules showed that they are stable in water at neutral pH and remain almost intact in simulated gastric fluid, but rapidly disintegrate when further treated with simulated intestinal fluid. These results demonstrated that calcium alginate-chitosan capsules can protect proteins from harsh gastric conditions and release their content at intestinal pH, demonstrating their potential application in the field of oral protein delivery.

Many advanced wound healing dressings exist, but there is little high-quality evidence to support them. To determine the performance of a novel amorphous hydrogel (EHO-85) in relation to its application, we compared its rheological properties with those of other standard hydrogels (SH), and we assessed the induction of acceleration of the early stages of wound healing as a secondary objective of a prospective, multicenter, randomized, observer-blinded, controlled trial. The patients were recruited if they had pressure, venous, or diabetic foot ulcers and were treated with EHO-85 (n = 103) or VariHesive® (SH) (n = 92), and their response was assessed by intention-to-treat as wound area reduction (WAR (%)) and healing rate (HR mm2/day) in the second and fourth weeks of treatment. Results: EHO-85 had the highest shear thinning and G′/G″ ratio, the lowest viscous modulus, G″, and relatively low cohesive energy; EHO-85 had a significantly superior effect over SH in WAR and HR, accelerating wound healing in the second and fourth weeks of application (p: 0.002). This superiority is likely based on its optimal moisturizing capacity and excellent pH-lowering and antioxidant properties. In addition, the distinct shear thinning of EHO-85 facilitates spreading by gentle hand pressure, making it easier to apply to wounds. These rheological properties contribute to its improved performance.

Many advanced wound healing dressings exist, but there is little high-quality evidence to support them. To determine the performance of a novel amorphous hydrogel (EHO-85) in relation to its application, we compared its rheological properties with those of other standard hydrogels (SH), and we assessed the induction of acceleration of the early stages of wound healing as a secondary objective of a prospective, multicenter, randomized, observer-blinded, controlled trial. The patients were recruited if they had pressure, venous, or diabetic foot ulcers and were treated with EHO-85 (n = 103) or VariHesive® (SH) (n = 92), and their response was assessed by intention-to-treat as wound area reduction (WAR (%)) and healing rate (HR mm2/day) in the second and fourth weeks of treatment. Results: EHO-85 had the highest shear thinning and G'/G″ ratio, the lowest viscous modulus, G″, and relatively low cohesive energy; EHO-85 had a significantly superior effect over SH in WAR and HR, accelerating wound healing in the second and fourth weeks of application (p: 0.002). This superiority is likely based on its optimal moisturizing capacity and excellent pH-lowering and antioxidant properties. In addition, the distinct shear thinning of EHO-85 facilitates spreading by gentle hand pressure, making it easier to apply to wounds. These rheological properties contribute to its improved performance.

Many advanced wound healing dressings exist, but there is little high-quality evidence to support them. To determine the performance of a novel amorphous hydrogel (EHO-85) in relation to its application, we compared its rheological properties with those of other standard hydrogels (SH), and we assessed the induction of acceleration of the early stages of wound healing as a secondary objective of a prospective, multicenter, randomized, observer-blinded, controlled trial. The patients were recruited if they had pressure, venous, or diabetic foot ulcers and were treated with EHO-85 (n = 103) or VariHesive® (SH) (n = 92), and their response was assessed by intention-to-treat as wound area reduction (WAR (%)) and healing rate (HR mm2/day) in the second and fourth weeks of treatment. Results: EHO-85 had the highest shear thinning and G′/G″ ratio, the lowest viscous modulus, G″, and relatively low cohesive energy; EHO-85 had a significantly superior effect over SH in WAR and HR, accelerating wound healing in the second and fourth weeks of application (p: 0.002). This superiority is likely based on its optimal moisturizing capacity and excellent pH-lowering and antioxidant properties. In addition, the distinct shear thinning of EHO-85 facilitates spreading by gentle hand pressure, making it easier to apply to wounds. These rheological properties contribute to its improved performance.

Mechanochemical synthesis methods are solid-state processes that constitute an alternative to those based on the use of liquid solvents. Mechanochemical methods have potential for industrial use as they are simple, scalable and environmental friendly. The solid-state reactions in mechanochemical synthesis can be used to obtain nanoparticles with small size and well-controlled crystallinity, at very low cost. Herein, we report on the mechanochemical synthesis of TiO2 photocatalytic nanoparticles, with controlled particle size and crystalline structure. Moreover, we also show that the bandgap of these TiO2 nanoparticles can be modified by carbon doping, so that they can display photocatalytic activity under visible light. The photocatalytic performance of various TiO2 nanoparticles has been evaluated by measuring the degradation of dyes. Moreover, upon convenient surface hydrophobization, the TiO2 nanoparticles can adsorb on liquid/liquid interfaces and become good stabilizers for highly concentrated emulsions. Such particle-stabilized emulsions were used as templates for the preparation of macroporous photocatalytic materials with a polymer matrix (photocatalytic polyHIPE).

Bitumen is a complex material with great interest because of technological applications in road construction. The properties of asphalt formulations greatly depend on adhesion of bitumen to gravel particles. In this context, colloidal and adhesion properties of bitumen are related to bitumen composition and surface tension. It is known that bitumen contain ionic species that define its interfacial properties. Many authors have denoted these molecules as “endogenous surfactants”, but nevertheless these ionic molecules might not be true surfactants. Herein, the physicochemical properties of bitumen are investigated at room temperature, which is not an easy task, since the extremely high viscosity of bitumen makes difficult to characterize its surface properties at low temperatures. First, characterization by FTIR, SWAXS, DSC and TGA has been performed. Zeta potential of bitumen-in-water emulsion droplets has also been measured as a function of a cationic surfactant concentration. It was found that zeta potential inverted from negative to positive, with surfactant addition. The point of charge inversion was used as a titration tool to determine the density of acid groups present on bitumen/water interface. Then, surface pH was calculated using the Ionizable Surface Group Model and Grahame equation. Ionic species of bitumen are partly soluble in water, and thus, able to decrease surface tension of water. The diffusion of these bitumen ionic species has been studied by measuring surface tension of water as a function of time, and applying Henry and Gibbs diffusion models. Regarding surface energy, it has been studied by depositing sessile drops of various liquids with different polarity, on bitumen thin films at room temperature, since this is the most appropriate method for highly viscous materials. The surface free energy and their respective polar and dispersive components, calculated by the Owens and Wendt approach, have been related to the chemical composition of bi

Nitrogen-doped nanoporous carbon fibers were prepared using chromonic perylene bisimide self-assemblies as templates. The method involves the formation of perylene-templated silica followed by carbonization and etching. This strategy does not require any additional carbon or nitrogen precursor and omits the associated impregnation step. The obtained carbon fibers were tested as electrode materials for supercapacitor applications. Owing to the high surface area (695 sq m/g) and well-developed porosity (pore volume ca.0.67 cu cm/g) with hierarchical micro- and mesopore structures, N-doping and high-wettability, amorphous carbon fibers showed excellent electrical double-layer capacitance with faradaic pseudocapacitance performance in an aqueous electrolyte solution (1M H2SO4). A working electrode prepared from the optimal sample achieved a high specific capacitance of 317 F/g at a current density of 1 A/g with excellent capacitance retention of 80% at a high current density of 50 A/g suggesting a fast electrolyte ion diffusion at the electrode surface. Also, the electrode showed outstanding cycle stability of 99% after 10,000 successive charge-discharge cycles. These results showed the high potential of chromonic-derived hierarchically porous carbon fibers as electrode materials for high-performance supercapacitors with advantages over electrospinning and catalytic fabrication methods, e.g., the absence of heavy metals and organic solvents in the preparation procedure.