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A new procedure for the bioactivation of alumina-based porous ceramic constructs was introduced. The constructs were built with the aim of mimicking the structural and mechanical properties of the human cortical bone. Bioactivation was achieved by adding wollastonite and acidic surface treatment (piranha solution). Structural studies (SEM, CAT) confirmed that adequate pore size and interconnectivity were obtained. Uniaxial compression tests showed that the values of Young's moduli and compressive strength were reduced, from 5 to 1 GPa, and from 45 to 15 MPa, respectively, as the wollastonite content increased from 0 to 40 wt.%. Proliferative, histological and fluorescence results confirmed that cell proliferation rate of bone-marrow-derived mesenchymal stem cells were significantly enhanced by increasing wollastonite content. No cytotoxic effect was observed. In summary, the fabricated bioceramics exhibited suggestive structural and mechanical properties and they could be useful for the practical bone tissue engineering applications without any adverse biological effects.

In this work, a procedure for fabricating porous alumina with the use of a carbon sacrificial template has been tested in order to optimize the fabrication of porous structures mimicking the porosity and mechanical properties of the human cortical bone. Two different sources of sacrificial carbon were used and compared, and different sintering and calcination routes were considered. The porosity of the alumina structures studied by Hg porosimetry revealed that the amount of porosity and the size and shape of the pores are still below the required values, although some acicular pores were clearly observed by SEM. Moreover, measured mechanical properties (Young’s modulus) remained below that of the bone, suggesting the need for further consolidation treatments. In summary, these encouraging results drive the optimization of future fabrication routes.

Nowadays, there exists a huge interest in producing innovative, high-performance, biofunctional, and cost-efficient electrospun biomaterials based on the association of biocompatible polymers with bioactive molecules. Such materials are well-known to be promising candidates for three-dimensional biomimetic systems for wound healing applications because they can mimic the native skin microenvironment; however, many open questions such as the interaction mechanism between the skin and the wound dressing material remain unclear. Recently, several biomolecules were intended for use in combination with poly(vinyl alcohol) (PVA) fiber mats to improve their biological response; nevertheless, retinol, an important biomolecule, has not been combined yet with PVA to produce tailored and biofunctional fiber mats. Based on the abovementioned concept, the present work reported the fabrication of retinol-loaded PVA electrospun fiber mats (RPFM) with a variable content of retinol (0 ≤ Ret ≤ 25 wt.%), and their physical–chemical and biological characterization. SEM results showed that fiber mats exhibited diameters distribution ranging from 150 to 225 nm and their mechanical properties were affected with the increasing of retinol concentrations. In addition, fiber mats were able to release up to 87% of the retinol depending on both the time and the initial content of retinol. The cell culture results using primary mesenchymal stem cell cultures proved the biocompatibility of RPFM as confirmed by their effects on cytotoxicity (low level) and proliferation (high rate) in a dose-dependent manner. Moreover, the wound healing assay suggested that the optimal RPFM with retinol content of 6.25 wt.% (RPFM-1) enhanced the cell migratory activity without altering its morphology. Accordingly, it is demonstrated that the fabricated RPFM with retinol content below the threshold 0 ≤ Ret ≤ 6.25 wt.% would be an appropriate system for skin regenerative application.

A cellular automata model has been developed to study the sintering behavior of ceramic particles. In this model, the only physical rule that drives the evolution of the system is to reduce the energy at the interface between the mass cells and the void cells. The meaning of several computational parameters, such as particle size or computational temperature, were investigated. Experiments of partial sintering of spherical particles of silica were performed and it was verified that this model successfully mimics the neck formation. Moreover, other experimental evidences of the stages of the densification, such as the formation of the intermediate vermicular microstructure or the dependence of porosity with temperature, were also qualitatively simulated.

In this work, a procedure for fabricating porous alumina with the use of a carbon sacrificial template has been tested in order to optimize the fabrication of porous structures mimicking the porosity and mechanical properties of the human cortical bone. Two different sources of sacrificial carbon were used and compared, and different sintering and calcination routes were considered. The porosity of the alumina structures studied by Hg porosimetry revealed that the amount of porosity and the size and shape of the pores are still below the required values, although some acicular pores were clearly observed by SEM. Moreover, measured mechanical properties (Young’s modulus) remained below that of the bone, suggesting the need for further consolidation treatments. In summary, these encouraging results drive the optimization of future fabrication routes.