A new biomaterial developed by scientists from Ireland can help regrow blood vessels and bone in patients with large bone defects. Bone has an innate capacity for regeneration when injured, but large bone defects caused by trauma, disease or tumour resection can’t heal on their own and remain a major clinical challenge. The research was led by the Royal College of Surgeons in Ireland (RCSI), which in earlier work had found that a protein-coding gene called the placental growth factor (PGF) grew new blood vessels and aided bone regeneration at different doses. With support from the EU-funded ReCaP project, the scientists used this knowledge to develop a biomaterial that delivers different doses of PGF to help repair bone defects that can’t heal spontaneously. The study was published in the ‘Journal of Controlled Release’. Mimicking natural bone regeneration, the biomaterial releases PGF at an initial high dose to promote blood vessel growth, and then follows this with a lower sustained PGF dose to promote bone regeneration. To make this possible, the research team incorporated PGF-loaded microparticles into a collagen/hydroxyapatite scaffold already containing directly incorporated PGF. While in vitro testing of the biomaterial showed only a moderate increase in bone regrowth, it resulted in robust bone regeneration when implanted in rats with bone defects. “More testing is needed before we can begin clinical trials, but if proven successful, this biomaterial could benefit patients when repairing bone defects by providing an alternative to current systems,” noted ReCaP project lead researcher Prof. Fergal O’Brien of the RCSI in a ‘EurekAlert!’ news release.
A mechanobiology-informed approach
To obtain these results, the researchers began with the hypothesis that the emerging scientific field of mechanobiology can be used to identify potential treatments that promote bone regeneration. Mechanobiology focuses on how physical forces and changes in the mechanical properties of cells influence cell behaviour, cell and tissue differentiation, and diseases related to these processes. “By using a mechanobiology-informed approach, we were able to identify a promising new therapeutic candidate for bone repair and also determine the optimal concentrations required to promote both angiogenesis and osteogenesis within a single biomaterial,” observed study first author Dr Eamon Sheehy of the RCSI and Trinity College Dublin in the news release. “The regeneration of large bone defects remains a significant clinical challenge, but hopefully our new biomaterial will continue to prove beneficial in further trials.” Besides repairing bone defects, the team’s mechanobiology-informed approach to regenerative medicine also “provides a new framework for evaluating regenerative biomaterials for other tissue engineering applications,” remarked Prof. O’Brien. “We are now applying this concept of ‘mechanobiology informed regenerative medicine’ to identify new therapeutics in other areas, including cartilage and spinal cord repair.” ReCaP (Regeneration of Articular Cartilage using Advanced Biomaterials and Printing Technology) aims to develop a paradigm-shifting disruptive technology that will revolutionise the treatment of joint injuries. The project ends in July 2023. For more information, please see: ReCaP project
ReCaP, bone, blood vessel, regeneration, defect, biomaterial, mechanobiology