title: Novel Perfused Compression Bioreactor System as an in vitro Model to Investigate Fracture Healing.
abstract: Secondary bone fracture healing is a physiological process that leads to functional tissue regeneration via endochondral bone formation. In vivo studies have demonstrated that early mobilization and the application of mechanical loads enhances the process of fracture healing. However, the influence of specific mechanical stimuli and particular effects during specific phases of fracture healing remain to be elucidated. In this work, we have developed and provided proof-of-concept of an in vitro human organotypic model of physiological loading of a cartilage callus, based on a novel perfused compression bioreactor (PCB) system. We then used the fracture callus model to investigate the regulatory role of dynamic mechanical loading. Our findings provide a proof-of-principle that dynamic mechanical loading applied by the PCB can enhance the maturation process of mesenchymal stromal cells toward late hypertrophic chondrocytes and the mineralization of the deposited extracellular matrix. The PCB provides a promising tool to study fracture healing and for the in vitro assessment of alternative fracture treatments based on engineered tissue grafts or pharmaceutical compounds, allowing for the reduction of animal experiments.
authors.affiliation: Department of Biomedicine, University Hospital Basel , Basel , Switzerland ; Department of Surgery, University Hospital Basel , Basel , Switzerland ; School of Life Sciences, Institute for Medical and Analytical Technologies, University of Applied Sciences Northwestern Switzerland , Muttenz , Switzerland.
authors.forename: Waldemar
authors.initials: W
authors.lastname: Hoffmann
authors.affiliation: Department of Biomedicine, University Hospital Basel , Basel , Switzerland ; Department of Surgery, University Hospital Basel , Basel , Switzerland.
authors.forename: Sandra
authors.initials: S
authors.lastname: Feliciano
authors.affiliation: Department of Biomedicine, University Hospital Basel , Basel , Switzerland ; Department of Surgery, University Hospital Basel , Basel , Switzerland.
authors.forename: Ivan
authors.initials: I
authors.lastname: Martin
authors.affiliation: School of Life Sciences, Institute for Medical and Analytical Technologies, University of Applied Sciences Northwestern Switzerland , Muttenz , Switzerland.
authors.forename: Michael
authors.initials: M
authors.lastname: de Wild
authors.affiliation: Department of Biomedicine, University Hospital Basel , Basel , Switzerland ; Department of Surgery, University Hospital Basel , Basel , Switzerland.
authors.forename: David
authors.initials: D
authors.lastname: Wendt
keywords: bioreactor; fracture healing; hypertrophy; in vitro model; mechanical loading