Low temperature additive manufacturing of three dimensional scaffolds for bone-tissue engineering applications: Processing related challenges and property assessment

Morphological, mechanical and biological assessment of PCL/pristine graphene scaffolds for bone regeneration

“…In this approach, scaffolds provide an initial biochemical substrate for the novel tissue until cells can produce their own extra-cellular matrix. An ideal scaffold for bone tissue engineering must be designed according to the following requirements [3,10,11,15,16] :  The scaffold material must be non-toxic and allow cell attachment, proliferation, and differentiation;  The scaffold material must degrade into non-toxic products under a controlled degradation rate;  The scaffolds should promote osteointegration, which corresponds to the formation of a chemical bond between bone and the surface of the implanted scaffold without the formation of fibrous tissue. They must also promote osteoconduction and osteogenesis, inducing chemical stimulation of human mesenchymal stem cells into bone-forming osteoblasts;  Scaffolds must be able to deliver growth factors, cytokines, and antibacterial materials.…”

Fabrication of 3D calcium phosphates based scaffolds using bacterial cellulose as template

“…The traditional synthetic porous scaffolds for bone implants present a number of disadvantages, which can be overcome by designing and fabricating new biomimetic architectures with appropriate compositional, microstructural, mechanical and biological features [31,32]. In this context, we report for the first time on the fabrication of calcium phosphates based scaffolds with controlled morphology starting from BC -calcium phosphates composites which were afterwards subjected to thermal treatment at high temperatures with the aim of completely remove the organic component and ensure the promotion of a 3D porous resistance structure.…”

Application of 3D printing technology in bone tissue engineering

“…In addition to macroscopically connected pores (pore size > 50 μm) for excellent vessel growth and material transport [6], suitable microscopic pores (pore size < 50 μm) are also key to optimal osteogenesis [24]. Pore structure parameters, including pore size, porosity, connectivity between pores, degree of distortion of connected pores, and surface area, affect osteogenesis.…”

“…Three-dimensional powder printing experiences the stages of binder spray, impacting on powder bed, expansion, fusion and curing. Each stage may affect the forming quality [6], such as the satellite droplets generated during the injection, the compressive load generated when impacting the powder bed that will cause the longitudinal displacement of the printed thin layer, the excessive diffusion of the binder on the powder bed and the strength of the bond. To obtain scaffold with the desired accuracy and strength, it is necessary to study the influencing factors and find specific solution for each molding method.…”