[en] In this work, we focused on the potential of bioceramics from different marine sponges—namely Petrosia ficiformis , Agelas oroides and Chondrosia reniformis— for novel biomedical/industrial applications. The bioceramics from these sponges were obtained after calcination at 750 °C for 6 h in a furnace. The morphological characteristics were evaluated by scanning electron microscopy (SEM). The in vitro bioactivity of the bioceramics was evaluated in simulated body fluid (SBF) after 14 and 21 d. Observation of the bioceramics by SEM after immersion in SBF solution, coupled with spectroscopic elemental analysis (EDS), showed that the surface morphology was consistent with a calcium-phosphate (Ca/P) coating, similar to hydroxyapatite crystals (HA). Evaluation of the characteristic peaks of Ca/P crystals by Fourier transform infrared spectroscopy and x-ray diffraction further confirmed the existence of HA. Cytotoxicity studies were carried out with the different ceramics and these were compared with a commercially available Bioglass^®. In vitro tests demonstrated that marine bioceramics from these sponges are non-cytotoxic and have the potential to be used as substitutes for synthetic Bioglass^®. (paper)

[en] Highlights: • Densities of aqueous solutions of 1 ChCl + 4 Phenol were measured from 20 to 50 °C. • A comprehensive volumetric investigation was carried out on the investigated mixtures. • All of the investigated mixtures showed negative excess molar volumes. In this study, the densities of the pseudo-binary systems of water and the deep eutectic solvent, 1 choline chloride + 4 phenol were measured and reported for the first time in literature, and a comprehensive investigation on the various volumetric properties was carried out. Nine mixtures, with different compositions of water, were prepared. The densities of the prepared mixtures, as well as pure water and pure deep eutectic solvent (DES) were measured within a temperature range of 293.15–333.15 K at atmospheric pressure. Various volumetric properties, such as excess molar volumes and isobaric volume expansions, partial molar volumes and excess partial molar volumes were calculated for the investigated compositions. Furthermore, partial molar volumes and excess partial molar volumes at infinite dilution were estimated for water and the DES. By analysing the calculated properties, the interstitial accommodation effect was suggested for the investigated mixtures. The stronger tendency of water to be solvated in the mixture, as compared to the DES, was observed for all investigated temperatures. This suggests that, most probably, hydrogen bonds in the investigated mixtures are established in a manner in which water molecules are located at central positions, surrounded by the DES pseudo-molecules.

[en] The aim of this study was to develop a new process for the production of bioactive 3D scaffolds using a clean and environmentally friendly technology. The possibility of preparing composite scaffolds of Bioglass and a polymeric blend of starch and poly(L-lactic acid) (SPLA50) was evaluated. Supercritical phase-inversion technique was used to prepare inorganic particles loaded starch-based porous composite matrixes in a one-step process for bone tissue engineering purposes. Due to their osteoconductive properties some glasses and ceramics are interesting materials to be used for bone tissue engineering purposes; however their poor mechanical properties create the need of a polymeric support where the inorganic fraction can be dispersed. Samples impregnated with different concentrations of Bioglass (10 and 15% wt/wt polymer) were prepared at 200 bar and 55 deg. C. The presence of Bioglass did not affect the porosity or interconnectivity of the polymeric matrixes. Dynamic mechanical analysis has proven that the modulus of the SPLA50 scaffolds increases when glass particles are impregnated within the matrix. In vitro bioactivity studies were carried out using simulated body fluid and the results show that a calcium-phosphate layer started to be formed after only 1 day of immersion. Chemical analysis of the apatite layer formed on the surface of the scaffold was performed by different techniques, namely EDS and FTIR spectroscopy and X-ray diffraction (XRD). The ion concentration in the simulated body fluid was also carried out by ICP analysis. Results suggest that a bone-like apatite layer was formed. This study reports the feasibility of using supercritical fluid technology to process, in one step, a porous matrix loaded with a bioactive material for tissue engineering purposes.

[en] Highlights: • The eutectic blend presents a melting temperature near the physiological temperature. • Particls from gas saturated solution (PGSS) led to a heterogenous dispersion of eutectic blend and higher cytotoxicity. • Derived version of rapid expansion of supercritical solution (D-RESS) allows a homogeneous dispersion of the eutectic blend along the gauze surface. • The antibacterial properties of the eutectic blend were not comprised after the D-RESS process. -- Abstract: In order to limit bacterial infections during wound treatment, it is interesting to consider the concept of loading medical devices with antibacterial agents. With this in mind, an innovative system with thermosensitive properties was produced: loading a commercially available gauze with a fatty acid eutectic blend based on lauric acid (LA) and myristic acid (MA). This eutectic blend presents a melting point near physiological temperature, which together with its antibacterial properties make an appealing alternative in biomedical applications. At room temperature, the properties and the efficacy of the eutectic blend loaded onto gauzes are preserved, whereas at physiological temperature the eutectic blend undergoes a phase change that facilitates its diffusion from the gauze. The loading of the eutectic blend onto gauzes was performed using two different supercritical fluid technologies, namely, particle from gas saturated solutions (PGSS) and a derived version of rapid expansion of supercritical solution (D-RESS). The PGSS led to a heterogeneous dispersion of the eutectic blend in the gauze, whereas the D-RESS process led to the formation of a homogeneous dispersion along the surface of the gauze. Additionally, with D-RESS no phase separation of the eutectic blend occurred and the cytotoxicity was greatly improved compared with PGSS without compromising the antibacterial properties of the fatty acid eutectic blend. Hence, the present study highlights the potential use of the flexible D-RESS process to load the fatty acid eutectic blend with antibacterial properties onto medical devices in a controllable way. Overall, the effects produced by the loaded gauzes suggest the enormous potential of the developed technology in health-related areas.