84 / 2018-06-18 18:50:49

OPTIMISATION OF 3D PRINTING PROCESS FOR PATIENT SPECIFIC BONE REGENERATION

3d printing,biomaterial,surgery,bone regeneration

全体主题 > ii. Biomaterials and formulation of novel “bioinks” for tissue-specific applications

Introduction
3D (bio) printing provides a unique opportunity to print on demand tissues (soft or hard) and organs, which can be used for tissue regeneration or organ restoration. However, there are number of challenges which need to be overcome before this technology can be successfully translated to clinical bench side [1]. The current work investigates a hard ink based on clinically approved hydroxyapatite (HA) for its printing accuracy, reproducibility and biocompatibility using extrusion based 3D printing process. Its printability and sintering have been optimised to match surgical requirements. Its translation into clinic is described and validated with an example of a clinical case of a radius surgery, where starting from the patient CT scan, a graft matching the defect was created and 3D printed.

Materials and Methods
Using extrusion based printer (INKREDIBLE+, Cellink), the ink based on clinically approved HA powder (Ceramysis Ltd.) was developed and tested. Its printability, shape accuracy, printing reproducibility and biocompatibility were tested as well as its sintering process. Finally, starting from a radius CT scan, a patient’s defect was reconstructed and its complementary graft was accurately designed. The defect was printed with a high resolution printer (SLA, Formlabs) and the graft was printed with HA ink. After sintering it was inserted in the defect and a CT-scan of the construct was taken for quality control and analysed (using Simpleware and ParaView softwares)

Results and Discussion
The developed HA ink is suitable for 3D printing and biocompatible. Scaffolds mechanical properties and volume shrinkage post-sintering depend on the infill density used. These parameters were quantified to tailor graft designs matching surgical requirements. Finally, the process starting from patient medical images to graft printing has been optimised and validated. The graft showed 96% matching with the defect.

Conclusions
Understanding the effect of infill density on volume shrinkage and mechanical properties helps matching surgical requirements and tailoring patient specific graft design. HA ink is biocompatible and can be used to print complex bony structures starting from patient's medical images.