Three-Dimensional Printed Polycaprolactone Scaffolds for Bone Regeneration Success and Future Perspective

Cells require a home. Three-dimensional printing provides the technology to enable the manufacture of 3D scaffolds with interconnected porosity. Three-dimensional printed medical grade polycaprolactone (mPCL) scaffolds were introduced more than 10 years ago as a scaffold for bone tissue engineering and implanted in more than 20,000 patients. The clinical successes from burr hole covers, dental ridge preservation, and customized cranioplasty to orbital floor repairs were attributed to the microstructure that mimics the trabecular bone, which encourages vascularization and cell-cell communications. The slow degradation of mPCL allows time for bone remodeling. Future perspective on translational bone tissue engineering will rely on the cocktail of cells (e.g., stem cells and neutrophils) that addresses angiogenesis from the beginning and the biodegradable products that can enhance the bone-forming cells. The latter is important as bone cells require trace elements of minerals such as magnesium to enable them to function in a sustainable manner. The effect of electromagnetic stimulation opens up new avenues. The search for clinical trials to directly assess the quality of the human bone safely in a manner that is approved by Ethics Committee has been one of the key focuses in many groups, and we propose the tooth socket dentoalveolar model. Impact Statement Cells need a home to proliferate and remodel; biomimicry of the microarchitecture and microenvironment is important, and with 10 years of history in more than 20,000 clinical applications of 3D printed medical grade polycaprolactone scaffolds, we present the lessons learnt and project the future.