Basingstoke, December 2014: Strengthening its continued design and build expertise for biomedical motion applications, LG Motion Limited has just completed the supply of a customised positioning system for the bioengineering innovator MICA BioSystems Ltd. Formed in 2010 by Keele University Professors Jon Dobson and Alicia J El Haj, the spin-out Company has developed a ‘mechanical conditioning bioreactor’ to support a patented technology invented at Keele’s Institute of Science and Technology in Medicine (ISTM). The benchtop laboratory machine aims to control cell behaviour by applying time varying magnetic forces to magnetic nanoparticles targeted to cell membrane receptors. The particles are oscillated by a motion controlled magnet array to vary the magnetic force and exposure factors applied. The technique is of wide interest for biomedical research and has very promising opportunities for the emerging technology fields of tissue engineering and regenerative medicine as well as providing an important tool for drug screening.
The MICA™ (Magnetic Ion Channel Activation) Bioreactor includes is specially designed incubator with provision for cell growth chambers or multi-well plates to be loaded and located in its upper area whilst the magnetic array is mounted beneath on the, LG Motion designed, motorised linear positioning stage. With its microstepping drive and integral indexer housed in a separate desktop console, researchers can initiate and adjust the stage speed and position using GUI software from a standard PC to set the oscillation rate, amplitude and duration parameters of the magnetic array – and thus produce the exact magnetic stress profile required for the application.
LG Motion was contacted by MICA BioSystems following successful design and supply to Prof. Dobson’s earlier spin-out company, nanoTherics, who also benefitted from a technology transfer initiative from Keele University. LG Motion’s work with nanoTherics included development for a similar oscillation process for gene transfection and they were able to bring this experience into the project for MICA.
The basic specification covered a single-axis positioning stage with travel range of 50 mm and positional repeatability to within 10 microns, with support frame and control electronics. During the early proposal stages of the project it was established that the Basingstoke based motion specialist could add value by including the bioreactor cabinet and the mounting bracketry for the magnet arrays as part of the scope of supply. As the bioreactor needed to be restricted to a convenient benchtop size, the aluminium machine framing support structure for the mechanical system was used to fix the cabinet’s fabricated steel panelling. This allowed a smart and attractive curved design style to be included with a reasonable build cost.
The vertical orientation of the stage and the relatively heavy overhung payload of the various interchangeable magnet arrays necessitated a robust design with a long-life capability to endure extended periods of oscillation over its working life. A dual linear bearing arrangement based on linear motion guides was preferred along with a rolled quality ballscrew that would economically provide the precision required. The microstepping motor driven stage includes adjustable over travel limit switches to protect the magnets and the incubator from collision whilst a home sensor maintains a datum position on initialisation as part of the routine to set up an oscillation profile. Other customer specified additions included water cooling inlet and outlet connections.
The single axis drive and indexer that includes a 230V AC power supply is installed in a smart benchtop mounted cabinet that meets BSI EN60204‐1 for EMC and LVD directives. A two metre cable connects the bioreactor to the control cabinet which includes a removable front panel with a safety reed switch to ensure that it is screwed in place before bioreactor operation. As with all LG Motion systems, wiring diagrams and user operation guidelines as well as programming and set-up software with full documentation is included.