Special Issue: Design of Bioreactor Systems for Tissue Engineering

Tissue engineering and, more broadly, regenerative medicine is moving into a phase where we are seeing potential therapies moving 'slowly but surely' from the laboratory into the clinic, i.e., from research to the clinic and into manufacturing. The numbers of cells required for cell therapy protocols can vary from tens of millions, to billions [1], and it is widely considered that such cell numbers can be produced in bioreactor systems. Thus, the bioreactor is becoming a key tool for culturing clinical numbers of human cells and the regenerative medicine industry will become increasingly reliant on such systems at the centre of cell therapy production and tissue engineering. This Special Issue of Processes contains papers in the area of " Design of Bioreactor Systems for Tissue Engineering ". Here we showcase the diversity and advances in research that contribute to developing effective systems for the culture and controlled differentiation of stem cells, or the combination of cells and biomaterials into functional tissue. Bioreactors are a mature technology in the more traditional biotechnology and bioprocessing industries, but in regenerative medicine they are still developing. There is an observable evolution to bioreactor systems technology in tissue engineering: their use as a research tool for cell culture; innovative modifications to enable 3D tissue culture and the provision of mechanical stimuli; a maturing of our understanding to enable rational modelling, design and optimisation of bioreactor systems. This evolution is reflected in the papers we have published in this Special Issue of Processes. The primary role for the use of bioreactors has been as a research tool and as a technique to facilitate cell culture. This Special Issue contains a comprehensive review of bioreactor systems, as applied to human bone tissue production. Sladkova and de Peppo [2] report how bioreactor systems have helped to advance the culture of cells on scaffolds. They discuss the principle types of bioreactors, considerations of their design and physiological relevance, and the perspectives for clinical translation.