Blending rules for 3-D printing bone

By combining synthetic polymers and natural materials it is possible to increase the range of characteristics that might be fabricated using 3-D printing of components, according to research published in the International Journal of Nano and Biomaterials. In a proof of principle, the team has demonstrated how one such blend emulates the material properties of bone.

Gajanan Thokal and Chandrakant Patil of Amravati University in Maharashtra, India, have investigated the potential of blends of polyamide (PA12) and nanocrystalline cellulose (NCC) with formic acid solution. The team used scanning electron microscopy (SEM) to investigate the structures of the components they produced using 3-D printing of these blends. Standard stress and strength tests were also carried out as well as porosity measurements.

Ultimately, the team demonstrated that certain formulations could mimic the structure and characteristics of bone, perhaps opening up the possibility of printing 3-D prosthetic bone parts for surgical repair and replacement. Such materials might have greater biocompatibility than conventional metal implants, the team suggests. There are also the advantages of improving the load bearing and re-implantation opportunities when a prosthetic implant ultimately wears out with use. In addition, such blended materials might well have improved bonding and implantation with the surrounding tissue due to their porous nature when compared with solid metal components.

The team points out that the specific type of bone their blended material emulates is that of the goat. As such animal trials of implants based on this substance might be carried out in this animal prior to their being used in humans although the specific formulation would inevitably require some modification for human use.