Monitoring and control of microbioreactors: an expert opinion on development needs.

This perspective article is based on an expert panel review on microbioreactor applications in biochemical and biomedical engineering that was organized by the M³C (measurement, monitoring, modelling and control) Working Group of the European Section of Biochemical Engineering Science (ESBES) in the European Federation of Biotechnology (EFB). The aim of the panel was to provide an updated view on the present status of the subject and to identify critical needs and issues for furthering the successful development of microbioreactor monitoring and control. This will benefit future bioprocess development and in vitro toxicity testing. The article concludes with a set of recommendations for extended use and further development of microbioreactors.

Proliferating and differentiating effects of three different growth factors on pluripotent mesenchymal cells and osteoblast like cells.

Growth factors are in clinical use to stimulate bone growth and regeneration. BMP-2 is used in long bone and spinal surgery, PDGFbb for the treatment of periodontal defects and children with growth hormone receptor deficiency are treated with IGF-I.Aim of the present study was the comparative analysis of the effect of these growth factors released from a local drug delivery system on cells of the osteogenic lineage at differing differentiation stages.The experiments with the mesenchymal cell line C2C12 revealed a proliferating effect of all three growth factors and a differentiating effect of BMP-2 with a dramatic increase in alkaline phosphatase activity. None of the growth factors stimulated cell migration.Human osteoblast like cells showed similar results with an increase in proliferation after stimulation with IGF-I or PDGFbb. The enzymatic activity of alkaline phosphatase was enhanced only in the cells stimulated with BMP-2. This group showed also more mineralized matrix compared to the other groups.In conclusion, the growth factors IGF-I and PDGFbb delivered with a local drug delivery system stimulated cell proliferation, whereas BMP-2 showed a dramatic effect on differentiation on osteoblast precursor cells and osteoblast like cells.