3DPRIN - 3DPRINting of multi-material parts for cranial implants

Abstract:

Additive Manufacturing is assessed as a competitive solution for fabricating customized and high-added-value products. For this reason, AM finds in the Medical sector one of the most prolific fields of application. Nevertheless, some aspects still need to be enhanced in biomedical applications.

This project will develop new AM solutions to overcome these limits. In particular, for fabricating parts made of heterogeneous materials, from polymers to metals, including customized biomedical, biocompatible and functionalized.

The case study selected for the project is related to Cranioplasty. Cranioplasty is a common procedure performed to repair cranial defects. When autologous bone is not available, a reconstruction with alloplastic materials can be realized. Customized cranial implants with PEEK (Polyether ether ketone) or titanium are valuable choices, achieving good aesthetic results. Indeed, their cost remains high. PMMA is often used to perform cranioplasty. It is biocompatible, easily shapeable and low-cost.

The novel engineered solution developed in the project consists in an implant made of a metal core embedded in polymeric shell that guarantees the required mechanical-biological properties. In fact, the polymeric material will be functionalized to enhance its biological interactions, to reduce the risk of post-surgery complications and to promote the osteointegration.

Because of the complexity of the problem, the product design involves many challenges such as anatomical fidelity, medical graded and functionalized materials, mechanical resistance, tissues reconstruction and interactions. Moreover, different fabrication process will be investigated: direct printing of implants, mold casting (e.g. of PMMA), implant production using rigid or flexible molds (e.g. made of silicone).

The Project involves partners with complementary skills and extensive backgrounds. Through an interdisciplinary approach, they will merge AM processes for customized materials, and the research value will be demonstrated by clinical cases with 2 levels of interest: planned and emergency surgeries. They share the same production approach in terms of types of product, design and production strategy. In fact, they need an implant and, eventually, a phantom of the patient for pre-surgery planning. Anatomical detailing and material requirements are calibrated on level of interest and clinical urgency. Parallel activities will be performed: i) biomaterials fabrication, customized mechanical and medical properties (antibacterial, drug release, in-vivo degradability, osteoconductivity, bioactivity); ii) process development and optimization; iii) development of implants for actual clinical cases; iv) validation of the implants by surgeons.

The continuous contribution of surgeons will allow to identify actual and significant clinical case-studies to demonstrate the consistency of the project results.