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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. [ABSTRACT FROM AUTHOR]

The present paper aims to overcome the problems related to previous use of autologous grafts using available synthetic grafts. To examine the optimum of the ideal vessel‐like constructs parameters are produced at 230 °C. At this production temperature, the elastic modulus values of the constructs ranges from 56 MPa to 174 MPa. The maximum cell proliferation is obtained from PCL/7wt.%CS/5wt.%H that is tested by mitochondrial dehydrogenase activity. The structures are visualized with all constructs after cell fixation by making use of the HUVEC cell line. In this study, multi component system containing Alginate, Hyaluronic Acid, Collagen type I, PCL and Chitosan intended to be used by 3D printing. The combination of Alginate, Hyaluronic Acid and Collagen type I was called hydrogel and the effects of hydrogel concentration on chemical, thermal, mechanical, morphological and biocompatibility properties of the fabricated vessel constructs were investigated. This multicomponent system combined with 3D printing can be used for vascular tissue engineering applications. [ABSTRACT FROM AUTHOR]

In recent years, 3D printed scaffolds becoming a widespread tool, which supports the repair mechanism of natural tissues. In order to support this knowledge, we used 3D printing methods to fabricated Chitosan (CH)/poly(vinyl alcohol)(PVA)-based scaffolds contains with a various ratio of hydroxyapatite (HA) (2.5, 5, 10, and 15 wt%). These composited scaffolds were further characterized for their chemical, morphological, mechanical, and biocompatibility properties. Scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), swelling test, and compressive strength test were performed to reveal structural, mechanical and chemical characteristics of scaffolds. Among others, 15 wt% HA contained group demonstrated significantly superior and beneficial features in printing quality. Also, the results reveal that scaffolds have similar elastic modulus to natural bone. Bone morphogenetic protein-2 (BMP-2) protein was added to the most successful mechanically produced sample. As a result, it was shown that Chitosan/PVA/HA (15 wt%) with BMP-2 tissue scaffold could form a three-dimensional natural extracellular scaffold suitable for human mesenchymal stem cells. Altogether, these results show that hydroxyapatite added scaffolds produced may be a promising approach for bone tissue engineering applications. • FTIR results showed that hydroxyapatite was successfully sintered at 600 °C and particles size were at about 55.54 μm. • The 36 layer of 15 wt.% of hydroxyapatite/Chitosan/PVA scaffolds were also successfully printed by a 3D printing. • Due to this structure, the elastic modulus of the scaffold was determined at 91.14 MPa. • 3D printed of CH/PVA/HA(15 wt.%) and CH/PVA/HA(15 wt.%)/BMP-2 scaffolds showed good biocompatibility, enhanced the attachment and proliferation of MSCs. [ABSTRACT FROM AUTHOR]