Controlling Cartilage to Bone Transitions for Improved Treatment of Bone Defects and Osteoarthritis

Project Information

CarBon

Grant agreement ID: 721432

DOI

10.3030/721432

Project closed

EC signature date 25 August 2016

Start date 1 January 2017

End date 31 December 2020

Funded under

• EXCELLENT SCIENCE - Marie Skłodowska-Curie Actions

Total cost

€ 3 607 596,36

EU contribution

€ 3 607 596,36

Coordinated by

ERASMUS UNIVERSITAIR MEDISCH CENTRUM ROTTERDAM
Netherlands

Periodic Reporting for period 2 - CarBon (Controlling Cartilage to Bone Transitions for Improved Treatment of Bone Defects and Osteoarthritis)

Reporting period: 2019-01-01 to 2020-12-31

Summary of the context and overall objectives of the project

CarBon was a Marie Curie Innovative Training Network. The aims were to increase our understanding of how cartilage turns into bone. Cartilage and bone are inextricably linked during development, pathology and repair. During skeletal development most bones of the body are formed via a cartilage intermediate through the process of endochondral ossification. In the context of bone healing, endochondral ossification is also critically important. At the joint surface, in the absence of disease, cartilage is a stable tissue that provides the mechanical environment required for joint motion. However, in osteoarthritis, undesirable endochondral ossification occurs whereby the cartilage becomes vascularised, mineralised and is eventually replaced by bone. Damage and disease related to cartilage and bone as described above place a huge burden on society in socioeconomic terms.
We investigated the role of cell behaviour, the extracellular matrix and the mechanical environment in cartilage formation and cartilage to bone transition, in order to ultimately develop new treatment options for large bone defect repair and the prevention or treatment of osteoarthritis. Important critical biological steps during the formation of cartilage and bone, such as cellular differentiation, the migration of cells and the generation of a vasculature were investigated using a broad range of models.
To achieve these aims, 14 early stage researchers (ESRs) were employed. The combination of biologists and engineers, academics and non-academics created a dynamic environment in which these researchers could develop their ideas. The first 3 workpackages (WPs) investigated the role of cell-secreted signaling molecules, extracellular matrix components and mechanical loading. WP4 and WP5 linked all knowledge using various types of models.
CarBon has delivered a new generation of scientists, skilled in multi-disciplinary research and well educated in economic, clinical and societal valorisation. As a result of the research activities, new targets have been discovered for further development of novel therapies for bone and cartilage repair.

Work performed from the beginning of the project to the end of the period covered by the report and main results achieved so far

In WP1 we aimed to identify cell-secreted factors that stimulate or inhibit the process of cartilage to bone transition. Interesting molecules were identified using data mining on large genetic screens performed prior to this project. With a specific focus on the role of inflammation and angiogenesis, the involvement of the specific cell-secreted molecules was determined using in-vitro and in-vivo assays. This led to two potential target molecules that could be used to enhance vascularization and improve bone repair and a molecule that could be used in the treatment of osteoarthritis. Next to molecules, cells also secrete extracellular vesicles, which carry a wide range of signaling molecules that can affect cellular processes. We found that inflammatory conditions can affect the release profile of these extracellular vesicles by mesenchymal stem cells and that these vesicles could enhance bone repair.

In WP2 we examined the role of several cartilage matrix molecules and their degradation products in the induction and maintenance of cartilage and bone formation in development and disease. The impact of 3 selected matrix molecules was characterised. Two novel matrix molecules were identified as promising candidates to modulate processes involved with the maintenance of stable cartilage and regulation of bone formation. Furthermore, candidate molecules were incorporated into existing collagen type 1 based scaffolds, and the ability of such factors to exert beneficial effects on cartilage repair was determined.

In WP3 the role of mechanical stimulation in cartilage formation and endochondral ossification was examined. Many of the mechanisms behind this are still poorly understood. The effect of different forms and magnitudes of mechanical stimulation towards cellular behaviour and cartilage stability was determined using different in-vitro, ex-vivo and in-vivo models. A specific bioreactor system was developed and optimized for loading tissues and mechanical stimulation of an appropriate magnitude was found to protect from inflammation-induced cartilage damage. Specific pathways that are regulated by mechanical stimuli were identified, revealing specific drug targets for potential novel therapies to improve bone formation or cartilage stability.

In WP4 two different platforms for computational modeling of cell and tissue behaviour in cartilage were developed based on existing knowledge from the labs, literature and new data generated in the consortium. The first platform has revealed several pathways that might be of importance for cartilage to bone transition and drug combinations that were tested using in vitro models set up in the consortium. The other platform incorporated multi-scale physiological mechanical cues and predicted the fate of cartilage cells due to abnormal mechanical loading. This WP demonstrated the suitability of the generated computational platforms to identify key molecules and help select conditions for further testing towards therapy development.

WP5 represented the culmination of the work performed within this project to test novel findings from the other workpackages in small animal models. The potential of drug targets identified in WP1 and WP3 for osteoarthritis and fracture healing were determined. A new model for bone defect repair was established and evaluated as a useful tool. Furthermore, as a result of this WP, a drug discovery pipeline was successfully developed, utilising different techniques established by CarBon consortium partners.

CarBon has identified potential areas for exploitation and dissemination: The inclusion of novel molecules to biomaterial scaffolds represents an exploitable option for the development of “off the shelf” implantable biomaterials for the treatment of cartilage defects; The identification of new drug targets for the treatment of osteoarthritis; The development of devices for research or screening of new materials for the repair of cartilage or bone defects.

Progress beyond the state of the art and expected potential impact (including the socio-economic impact and the wider societal implications of the project so far)

The CarBon project has laid the foundation for further development of novel therapies for bone and cartilage repair, and treatment of osteoarthritis. We made use of pre-existing knowledge with the use of computational models for different biological processes. This enabled consortium members to identify candidate molecules and processes and to test different hypotheses more targeted and much faster in the laboratory. New molecules and pathways have been identified for further research as well as for developments of new treatments. Upon completion of the project, ESRs had progressed to positions in industry, academia and education, further enhancing the progress each of these societal partners. Furthermore, the active involvement of non-academic partners in the project has brought an industrial perspective to the consortium, while also directly benefiting these companies through the expansion of their technical service portfolio. With disorders of the musculoskeletal system affecting millions of patients worldwide, further development of therapeutic targets identified by the CarBon project may offer novel strategies for the successful treatment of such diseases, creating a very large socio-economic impact.

CarBon Consortium Meeting in Eindhoven February 2020

Scheme of coherence of CarBon workpackages

CarBon ESRs on a road trip in Ireland, March 2018