Magnetic microbubbles for localised imaging and drug delivery: Development, characterisation and preliminary application in vivo.
Stride E., Owen J., Mulvana H., Pankhurst Q., Tang M., Eckersley R.
The use of coated microbubbles in therapeutic applications, in particular drug delivery and gene therapy, has become a highly active area of research. There remain, however, some significant challenges to be overcome in order to fully realise the potential of microbubbles in these applications. In particular, the difficulty in controlling the concentration of microbubbles at a given site and in ensuring sufficient proximity between bubbles and target cells, has frequently led to disappointing results from in vivo studies. Recent work has indicated that incorporating magnetic nanoparticles into the microbubble coating may provide an effective strategy for overcoming these challenges. Further investigation to fully understand the mechanisms of enhancement and hence optimise the delivery protocols is however required and this is the aim of the present study. Results will be presented from flow phantom studies demonstrating manipulation of bubble suspensions under physiological flow conditions, from high speed imaging used to investigate the dynamic behaviour of single microbubbles and theoretical modelling conducted to support and interpret the experimental findings. Finally results demonstrating in vivo transfection in a mouse model will be presented confirming successful localisation of the transfection site.