a b s t r a c tDiabetic foot ulcers (DFUs) are a chronic, non-healing complication of diabetes that lead to high hospital costs and, in extreme cases, to amputation. Diabetic neuropathy, peripheral vascular disease, abnormal cellular and cytokine/chemokine activity are among the main factors that hinder diabetic wound repair. DFUs represent a current and important challenge in the development of novel and efficient wound dressings. In general, an ideal wound dressing should provide a moist wound environment, offer protection from secondary infections, remove wound exudate and promote tissue regeneration. However, no existing dressing fulfills all the requirements associated with DFU treatment and the choice of the correct dressing depends on the wound type and stage, injury extension, patient condition and the tissues involved. Currently, there are different types of commercially available wound dressings that can be used for DFU treatment which differ on their application modes, materials, shape and on the methods employed for production. Dressing materials can include natural, modified and synthetic polymers, as well as their mixtures or combinations, processed in the form of films, foams, hydrocolloids and hydrogels. Moreover, wound dressings may be employed as medicated systems, through the delivery of healing enhancers and therapeutic substances (drugs, growth factors, peptides, stem cells and/or other bioactive substances). This work reviews the state of the art and the most recent advances in the development of wound dressings for DFU treatment. Special emphasis is given to systems employing new polymeric biomaterials, and to the latest and innovative therapeutic strategies and delivery approaches.

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Pressure-composition diagrams were measured at different temperatures ranging from 293.15 to 353.15 K for different perfluoroalkanes including linear (perfluoro-n-octane), cyclic (perfluorodecalin and perfluoromethylcyclohexane), and aromatic compounds (perfluorobenzene and perfluorotoluene), at pressures up to 100 bar. Measurements were performed using a high-pressure cell with a sapphire window that allows direct observation of the phase transition. The different molecular structures were chosen in order to check the influence of the nature of the solvent on the carbon dioxide solubility. The soft-statistical associating fluid theory (soft-SAFT) equation of state (EoS) was used to describe the phase behavior of the mixtures studied, searching for transferable parameters with predictive capability. Optimized values for the chain length, Lennard-Jones (LJ) diameter, and dispersive energy are provided for the different perfluoroalkanes and for carbon dioxide. The effect of the explicit inclusion of a quadrupole moment on carbon dioxide, perfluorobenzene, and perfluorotoluene was studied by adding a polar term to the original soft-SAFT EoS.

The solubility of oxygen in n-hexane and in n-perfluorohexane was determined experimentally and calculated by computer simulation. A precision apparatus based on a saturation method at constant pressure was used to measure the solubility at temperatures from 288 to 313 K and close to atmospheric pressure. Henry's law coefficients, H 2,1 (T,p sat 1 ), were obtained from the experimental data and their temperature dependence was represented by appropriate correlations. The precision of the results was characterised by average deviations of H 2,1 from these smoothing equations and is of AE0.5% and AE0.8% for oxygen in n-hexane and in n-perfluorohexane, respectively. From the temperature variation of the Henry's law coefficients, partial molar solvation quantities such as the variation of the Gibbs energy, enthalpy and entropy were derived. Molecular dynamics simulations with all-atom force fields, associated with Widom's test particle insertion method, were used to calculate the residual chemical potential of oxygen in the two solvents studied leading to Henry's law coefficients which were then compared to the experimental values. The difference between oxygen solubility in the two solvents was interpreted on the basis of solute-solvent interactions and structural properties such as solute-solvent radial distribution functions.

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