Why does an orthopaedic biofabrication project have polymers at its heart

Biofabrication of Orthopaedics in a New Era (BONE) will study how biodegradable polymers with bioactive properties can steer cell activity and tissue regeneration.

A European transnational consortium led by Maastricht University (UM) will spend the next four years developing innovative bone implants. These implants will become an alternative for repeat surgeries, prolonged medication use and donor tissue implementation following complex bone fractures. The BONE partnership will also provide the participating regions with a significant economic boost, where advances in polymer processing will be central to innovation.

Bone implants and consortium

Research has demonstrated that residents of Northwestern Europe are more likely to develop degenerative bone disorders in comparison with their EU counterparts. As a result, this region has the highest number of bone fractures and bone defects within Europe, which has evident social and economic consequences. In the field of regenerative medicine, researchers have been working hard to create innovative bone implants that can enhance recovery times and reduce health care costs. In addition to UM, this international partnership consists of the universities of Leuven (Belgium) and Lille (France), Fraunhofer Institute for Laser Technology ILT in Aachen (Germany), Medicen Paris Region, a leading biomedical cluster in Paris (France) and enabling technology companies The Electrospinning Company (UK), NKT Photonics (International) and Spraybase (Ireland). Over the next four years, these partners will work together developing the technology needed to produce these implants. The project initiators will also establish a roadmap to manufacture and market these implants at the end of the project, to ensure long term impact of their actions.

Technology

At the basis of these smart bone implants lies an innovative technology, known as electrospinning. This technology enables researchers to create implants that have the potential to help the regeneration of healthy bone tissue. The surface properties of newly developed bone implants will be improved by providing enhanced bioactivity to a library of biodegradable polymers. The project will evaluate, in particular, polyesters, polyurethanes and copolymers. These classes of biodegradable and biocompatible polymers already have applications in a number of medical devices. Yet, the bone regeneration market is mostly comprised by autologic or allogenic bone grafts as golden standard clinical procedures, and by bone morphogenetic protein formulations and ceramics as alternative biologic and synthetic products.

Whereas bone grafts are still linked to drawbacks such as morbidity (i.e. the lack of a bony site where bone could be taken), lack of revascularization and integration with the surrounding tissues, and risks of disease transmissions, their synthetic counterparts are costly (in case of bone morphogenetic proteins) and suffer from low mechanical properties (brittleness in case of ceramics).

Polymers could provide a cost-effective solution. By engineering the surface properties of the above mentioned targeted polymers, the project aims to obtain similar biological activity as bone grafts and bone morphogenetic proteins, while improving upon the mechanical properties of ceramics.

Furthermore, polymers offer the high flexibility to be synthesised with tailored end groups that could offer multiple sites for biological functionalisation. This could offer an appealing route to direct not only bone regeneration, but also vascularisation and innervation, aiming at an improved integration with the surrounding tissue.