Many parameters of fused deposition modeling (FDM) influence the resulting mechanical properties. This can become a key factor if those parts are intended for commercial applications. This study focuses on the influence of nozzle temperature and infill line orientations for parts made with short carbon fiber (CF)-reinforced polylactic acid (PLA). Tests bars made of PLA and PLA-CF composite were produced under carefully selected conditions. As expected, PLA-CF yields higher tensile properties compared to PLA, owing to the strengthening effect of high modulus CFs. Maximum tensile properties are attained for a nozzle temperature of 230°C, for both PLA and PLA-CF. This temperature was thus selected for probing the effects of infill orientations in test bars. Among the multiple orientations tested, the combination [0°, 15°, −15°] relative to the long axis of the test bar yields the highest levels of tensile properties for both PLA and PLA-CF over the “all-purpose” [45°, 135°] orientation. Annealing can also affect crystallinity and mechanical properties of manufactured parts. Through differential scanning calorimetric analyses, the degree of crystallinity was assessed for samples annealed under various conditions. Results show that annealing increases crystallinity in PLA and PLA-CF samples, with a lower cooling rate yielding higher values. The Young’s modulus exhibits the same behavior for annealed and as printed parts, with a lower cooling rate yielding higher modulus values. This is attributed to a relaxation of the material structure as well as to the orientation of polymer chains toward the CFs.

The effects of the magnesium doping of binary glass (Si–Ca) on particle texture, on the biomineralization process in simulated body fluid (SBF) as well as on drug loading and release were examined. For this purpose, magnesium-doped binary bioglass nanoparticles (85SiO₂–(15 − x)CaO–xMgO, with x = 1, 3, 5 and 10 mol%) were prepared by a base catalysed sol–gel method. N₂ adsorption isotherm analysis showed an enhancement in specific surface area as the Mg molar fraction increased. In addition, the FTIR spectra of the samples after soaking in SBF for various periods of time confirmed the presence of new chemical bonds related to the apatite phase, as was also confirmed by SEM observations. XRD patterns of the samples after soaking revealed that the crystallization to form a more stable apatite-like phase was hindered with increasing magnesium content in the glass composition. Furthermore, it was proved that the kinetics of drug release improved with increasing magnesium content. The porosity and the specific surface area were found to be responsible for this improvement.

Because of their excellent biologically active qualities, bioactive glasses (BGs) have been extensively used in the biomedical domain, leading to better tissue–implant interactions and promoting bone regeneration and wound healing. Aside from having attractive characteristics, BGs are appealing as a porous scaffold material. On the other hand, such porous scaffolds should enable tissue proliferation and integration with the natural bone and neighboring soft tissues and degrade at a rate that allows for new bone development while preventing bacterial colonization. Therefore, researchers have recently become interested in a different BG composition based on borate (B₂O₃) rather than silicate (SiO₂). Furthermore, apatite synthesis in the borate-based bioactive glass (BBG) is faster than in the silicate-based bioactive glass, which slowly transforms to hydroxyapatite. This low chemical durability of BBG indicates a fast degradation process, which has become a concern for their utilization in biological and biomedical applications. To address these shortcomings, glass network modifiers, active ions, and other materials can be combined with BBG to improve the bioactivity, mechanical, and regenerative properties, including its degradation potential. To this end, this review article will highlight the details of BBGs, including their structure, properties, and medical applications, such as bone regeneration, wound care, and dental/bone implant coatings. Furthermore, the mechanism of BBG surface reaction kinetics and the role of doping ions in controlling the low chemical durability of BBG and its effects on osteogenesis and angiogenesis will be outlined.