Hydroxyapatite (HA) promotes excellent bone regeneration in bone-tissue engineering, due to its similarity to bone mineral and its ability to connect to living tissues. These factors promote the osteointegration process. This process can be enhanced by the presence of electrical charges, stored in the HA. Furthermore, several ions can be added to the HA structure to promote specific biological responses, such as magnesium ions. The main objective of this work was to extract hydroxyapatite from sheep femur bones and to study their structural and electrical properties by adding different amounts of magnesium oxide. The thermal and structural characterizations were performed using DTA, XRD, density, Raman spectroscopy and FTIR analysis. The morphology was studied using SEM, and the electrical measurements were registered as a function of frequency and temperature. Results show that: (i) an increase of MgO amount indicates that the solubility of MgO is below 5%wt for heat treatments at 600 °C; (ii) the rise of MgO content increases the capacity for electrical charge storage; (iii) sheep hydroxyapatite presents itself as a natural source of hydroxyapatite, environmentally sustainable and low cost, and promising for applications in regenerative medicine.

Three-dimensional (3D) printing technology allows foods to be shaped into unique and complex. Chocolate is frequently used in food printing due to its extrusion melting capacity and attractiveness. In this study, chocolates enriched with ω-3 were produced with 3D printing technology. Using electrospraying, ω-3 was encapsulated within sodium alginate (SA) microparticles, and 3D printed chocolates were coated with those microparticles. Then, the ω-3 blend and ω-3-SA coated chocolates were compared. Before printing, the rheological properties of chocolate were analysed. In addition to their characteristics, the printed chocolates were evaluated for total phenolic content (TPC) and antioxidant capacity, in vitro gastrointestinal digestion, and ω-3 release profile. Fourier transform infrared (FTIR) spectroscopy indicated that ω-3 was successfully incorporated into the SA particles. According to the mechanical testing, the chocolate structures coated with ω-3-SA exhibited higher compressive strength than structures mixed with ω-3. The results revealed that the incorporation of alginate into pure chocolate scaffolds through the coating process resulted in an increase in compressive strength. The TPC and antioxidant capacities of ω-3-SA microparticles (NP) coated and ω-3 mixed chocolate samples were also significantly increased compared to those of pure chocolate after in vitro digestion. ω-3-SA NP-coated chocolate appeared to have a lower quality release profile. The faster release of encapsulated ω-3 at a pH value of 7 may be attributed to the fact that sodium alginate particles dissolve faster in high pH environments. This study revealed that 3D printing technology could be actively leveraged to create food-based products with the necessary ingredients to meet consumer demand.

Subchondral plate degeneration presents significant challenges in the treatment of osteochondral defects and requires innovative approaches for effective regeneration. The cooperative existence of multiple layer types with different characteristics makes it difficult to meet the mechanical and biochemical requirements of subchondral tissue. Direct Ink Writing (DIW) allows complex, structured scaffolds to be fabricated at room temperature while preserving material integrity and bioactivity. The aim of this study was to produce a bilayered scaffold based on poly(e-caprolactone), polyethylene glycol and hydroxyapatite that mimics the characteristics of subchondral bone and calcified cartilage in the native subchondral plate. Printability tests were performed to determine the optimal polymer concentration. The morphological and chemical properties of the 3D-printed scaffolds were analyzed using Scanning Electron Microscopy (SEM) and Fourier Transform Infrared Spectroscopy (FTIR). The presence of hydroxyapatite was found to enhance the swelling and degradation properties of the scaffolds. Mechanical characterization revealed distinct tensile strength and stiffness gradients between the bone layer (BL) and the calcified cartilage layer (CCL). The BL exhibited a Young’s modulus of 167.45 ± 57.51 MPa and a tensile strength of 4.05 ± 0.27 MPa. In contrast, the CCL showed a lower modulus of 21.95 ± 0.43 MPa and a tensile strength of 2.33 ± 0.25 MPa. These values align with the mechanical gradient of native tissue. Numerical analysis predicted the scaffold’s behavior under compressive force. Furthermore, in vitro cell culture studies demonstrated biocompatibility, showing that all scaffolds were biocompatible with cell viability exceeding 83% after seven days. Overall, the developed bilayered, 3D-printed scaffolds could be a potential tissue-engineered solution for treating subchondral plate degeneration.

This study focuses on the fabrication and comprehensive characterization of electrospun nanofibrous scaffolds composed of based on PLA/CH/GelMA, and varying concentrations of HAP (0.1, 0.3, and 0.5% w/v) for bone tissue engineering.