The 3D printing process offers several advantages to the medical industry by producing complex and bespoke devices that accurately reproduce customized patient geometries. Despite the recent developments that strongly enhanced the dominance of additive manufacturing (AM) techniques over conventional methods, processes need to be continually optimized and controlled to obtain implants that can fulfill all the requirements of the surgical procedure and the anatomical district of interest. The best outcomes of an implant derive from optimal compromise and balance between a good interaction with the surrounding tissue through cell attachment and reduced inflammatory response mainly caused by a weak interface with the native tissue or bacteria colonization of the implant surface. For these reasons, the chemical, morphological, and mechanical properties of a device need to be designed in order to assure the best performances considering the in vivo environment components. In particular, complex 3D geometries can be produced with high dimensional accuracy but inadequate surface properties due to the layer manufacturing process that always entails the use of post-processing techniques to improve the surface quality, increasing the lead times of the whole process despite the reduction of the supply chain. The goal of this work was to provide a comparison between Ti6Al4V samples fabricated by selective laser melting (SLM) and electron beam melting (EBM) with different building directions in relation to the building plate. The results highlighted the influence of the process technique on osteoblast attachment and mineralization compared with the building orientation that showed a limited effect in promoting a proper osseointegration over a long-term period.

Cobalt-chromium-molybdenum (Co-Cr-Mo) alloys are very promising materials, in particular, in the biomedical field where their unique properties of biocompatibility and wear resistance can be exploited for surgery applications, prostheses, and many other medical devices. While Additive Manufacturing is a key technology in this field, micro-milling can be used for the creation of micro-scale details on the printed parts, not obtainable with Additive Manufacturing techniques. In particular, there is a lack of scientific research in the field of the fundamental material removal mechanisms involving micro-milling of Co-Cr-Mo alloys. Therefore, this paper presents a micro-milling characterization of Co-Cr-Mo samples produced by Additive Manufacturing with the Selective Laser Melting (SLM) technique. In particular, microchannels with different depths were made in order to evaluate the material behavior, including the chip formation mechanism, in micro-milling. In addition, the resulting surface roughness (Ra and Sa) and hardness were analyzed. Finally, the cutting forces were acquired and analyzed in order to ascertain the minimum uncut chip thickness for the material. The results of the characterization studies can be used as a basis for the identification of a machining window for micro-milling of biomedical grade cobalt-chromium-molybdenum (Co-Cr-Mo) alloys.

The term “tissue engineering” refers to applications related with the repair or replacement of portions or whole tissue (i.e., bone, cartilage, blood vessels, skin, muscle etc.). Often, the tissues involved require certain mechanical and structural properties for their proper functioning. This leads to three-dimensional scaffolds fabrication to support cellular in-growth and proliferation. Scaffolds having tailored, biomimetic (across multiple scales) geometries have become important. Various technologies come together to construct porous scaffolds to regenerate the tissues and also for controlled and targeted release of bioactive agents in tissue engineering applications. The objective of the present work is to produce porous polymeric scaffolds made of Poly (ɛ-Caprolactone) (PCL), by electrospinning. Electrospinning is a process whereby ultra-fine fibers are formed in a high-voltage electrostatic field. The electrospun structure has a morphology similar to the extracellular matrix (ECM) of natural tissue, which is characterized by a wide range of pore diameters distribution, high porosity, and effective mechanical properties and is capable of supporting cells attachment and proliferation. The effects of process variables such as voltage, solution concentration and deposition distance on the structure have been studied. A combination of elongated beads and fibers, known as the bead-on-string morphology is also observed under many conditions. The fibrous structure is stabilized at high concentrations and voltages. The functional complexity of electrospun scaffolds provides significant advantages over other techniques. The wide range of structural characteristics that may be obtained in an electrospun polymer makes it suitable for many biomedical applications including medical textiles, drug delivery, membrane separation and organ regeneration. However, improvements are required before optimal utilization in vivo becomes routine. Improved deposition efficiency is necessary to maintain the attractiveness of this technique