In human daily life, bone cancer, osteosarcoma, osteomyelitis, artificial joint malfunction, bone fracture etc. are the reasons for bone defect. It is possible to prepare bone tissue from deceased donor patient although there is a risk of virus infection. In addition, that act itself might be difficult due to religious reasons. On the other hand, transplanting own ilium bone or calf bone, named as autologous bone graft is another way although one has to be aware of limited volume availability. Some studies are reporting that autologous bone graft operation could cause some pain afterwards.
In this respect, bone substitute material and artificial bone development could be promising technology. In the early development stage, metal such as titanium or ceramic materials have been studied in order to make robust artificial bone. However, their bone compatibility was not good and they were not suitable for long time usage especially for children. In the 1980s, artificial bones composed of hydroxyapatite or β-TCP (tricalcium phosphate) were developed and since then, the demand and expectation towards this type of artificial bone has grown rapidly.
Even though, they still had problems because those materials were solid and were hard to be adjusted to the desired shape. Thus, the powder, block and pumice stone formed hydroxyapatite or β-TCP were developed. Nevertheless, those materials did not satisfy the actual demand at surgery due to difficulty in terms of shape modification.
To reproduce body tissue which is similar to human bone, it is necessary to make precise three-dimensional structures so that one can apply them at actual surgery. In this regard, a 3D printer is the best choice to design complex desired structure for each patient. We can even expect to create custom made materials and structure for each patient expectation.
Poly lactic acid (PLA) is the biodegradable resin which can be used for human body and it has already been applied as bone junction material.
For these reasons, Dr. Ryohei Mori, Daiki Tanaka, Hirohisa Iwabayashi at Green Science Alliance have developed 3D printable PLA / Hydroxyapatite composite material to meet these demands and expectation.
In addition, recently, scaffold for tissue regenerative medicine has been an active research topic. As mentioned above, PLA possess biodegradability, human body compatibility although it does not respond to cell proliferation. Therefore, it cannot be applied to adhesion or joint material for cell culture or tissue regeneration. For this purpose, we can also expect same PLA / hydroxyapatite composite material to improve bone tissue, culture cell development because they contain hydroxyapatite.
Green Science Alliance is also planning to prepare biodegradable resin and some functional materials including β-TCP (β-tricalcium phosphate: this material has higher bone substitution ability then hydroxyapatite), collagen etc. in order to create further advanced biomaterials.