Due to the fact of their ability to bond with human’s hard tissue, bioglasses have gained interest in the biomedical field with certain purposes regarding their usage in the replacement, healing or repair of bones. In the form of thin films, they trigger an increase in biocompatibility for the inert supports after implantation, based on surface engineering to ensure osteoinduction. For that, this research is focused on obtaining coatings based on cerium-enriched bioglass to generate bioactive and potential additional antimicrobial and antioxidant properties. The addressed oxide system was a novel and complex one, 46.10 SiO2–2.60 P2O5–16.90 CaO–10.00 MgO–19.40 Na2O–5.00 CeO2 (mol%), while two different synthesis methods, laser ablation and spin coating, were tackled comparatively. In the case of the first technique, substrate temperature was selected as variable parameter (room temperature or 300 °C). After conducting a complex characterization, films’ deposition was validated, their bioactive behaviour was proven by the formation of calcium phosphate after immersion in simulated body fluid for four weeks, while the impact exerted on the tested human fibroblast BJ cells (ATCC, CRL-2522) confirmed the applicative potential.
In this work, composite fibers connected in three-dimensional porous scaffolds were fabricated by electrospinning, starting from polycaprolactone and inorganic powders synthesized by the sol-gel method. The aim was to obtain materials dedicated to the field of bone regeneration, with controllable properties of bioresorbability and bioactivity. The employed powders were nanometric and of a glass-ceramic type, a fact that constitutes the premise of a potential attachment to living tissue in the physiological environment. The morphological characterization performed on the composite materials validated both the fibrous character and oxide powder distribution within the polymer matrix. Regarding the biological evaluation, the period of immersion in simulated body fluid led to the initiation of polymer degradation and a slight mineralization of the embedded particles, while the osteoblast cells cultured in the presence of these scaffolds revealed a spatial distribution at different depths and a primary networking tendency, based on the composites’ geometrical and dimensional features.
The main objective of the tissue engineering field is to regenerate the damaged parts of the body by developing biological substitutes that maintain, restore, or improve original tissue function. In this context, by using the electrospinning technique, composite scaffolds based on polycaprolactone (PCL) and inorganic powders were successfully obtained, namely: zinc oxide (ZnO), titanium dioxide (TiO2) and hydroxyapatite (HAp). The novelty of this approach consists in the production of fibrous membranes based on a biodegradable polymer and loaded with different types of mineral powders, each of them having a particular function in the resulting composite. Subsequently, the precursor powders and the resulting composite materials were characterized by the structural and morphological point of view in order to determine their applicability in the field of bone regeneration. The biological assays demonstrated that the obtained scaffolds represent support that is accepted by the cell cultures. Through simulated body fluid immersion, the biodegradability of the composites was highlighted, with fiber fragmentation and surface degradation within the testing period.
The current work focuses on the development of mineral scaffolds with complex composition and controlled morphology by using a polymeric template in the form of nonwoven fibre webs fabricated through electrospinning. By a cross-linking process, gelatine fibres stable in aqueous solutions were achieved, these being further subjected to a loading step with two types of mineral phases: calcium phosphates deposited by chemical reaction and barium titanate nanoparticles as decoration on the previously achieved structures. Thus, hybrid materials were obtained and subsequently processed in terms of freeze-drying and heat treating with the purpose of burning the template and consolidating the mineral part as potential bone implants with improved biological response by external stimulation. The results confirmed the tunable morphology, as well as the considerable applicability of both as-prepared and final samples for the development of medical devices, which encourages the continuation of research in the direction of assessing the synergistic contribution of barium titanate domains polarisation/magnetisation by external applied fields.
The current study reports on the fabrication of composite scaffolds based on polycaprolactone (PCL) and cerium (Ce)-containing powders, followed by their characterization from compositional, structural, morphological, optical and biological points of view. First, CeO2, Ce-doped calcium phosphates and Ce-substituted bioglass were synthesized by wet-chemistry methods (precipitation/coprecipitation and sol-gel) and subsequently loaded on PCL fibres processed by electrospinning. The powders were proven to be nanometric or micrometric, while the investigation of their phase composition showed that Ce was present as a dopant within the crystal lattice of the obtained calcium phosphates or as crystalline domains inside the glassy matrix. The best bioactivity was attained in the case of Ce-containing bioglass, while the most pronounced antibacterial effect was visible for Ce-doped calcium phosphates calcined at a lower temperature. The scaffolds were composed of either dimensionally homogeneous fibres or mixtures of fibres with a wide size distribution and beads of different shapes. In most cases, the increase in polymer concentration in the precursor solution ensured the achievement of more ordered fibre mats. The immersion in SBF for 28 days triggered an incipient degradation of PCL, evidenced mostly through cracks and gaps. In terms of biological properties, the composite scaffolds displayed a very good biocompatibility when tested with human osteoblast cells, with a superior response for the samples consisting of the polymer and Ce-doped calcium phosphates.
Three different inorganic scaffolds were obtained starting from the oxide system SiO2‒P2O5‒CaO‒MgO, to which Ce4+/Sm3+/Sr2+ cations were added in order to propose novel materials with potential application in the field of hard tissue engineering. Knowing the beneficial effects of each element, improved features in terms of mechanical properties, antibacterial activity and cellular response are expected. The compositions were processed in the form of scaffolds by a common sol-gel method, followed by a thermal treatment at 1000 and 1200 °C. The obtained samples were characterized from thermal, compositional, morphological and mechanical point of view. It was shown that each supplementary component triggers the modification of the crystalline phase composition, as well as microstructural details. Moreover, the shrinkage behavior is well correlated with the attained compression strength values. Sm was proven to be the best choice, since in addition to a superior mechanical resistance, a clear beneficial influence on the viability of 3T3 fibroblast cell line was observed.