Dr Sean McGinty

Project Title: Mathematical modelling of sonoporation for a liquid crystal shell microbubble

In recent years, there has been significant interest in using thin-shelled microbubbles as a transportation mechanism for localised drug delivery, particularly in the context of cancer treatment. However, despite significant research activity, the full potential of this technology has not yet been realised. In this project, we proposed a radically new type of microbubble, and developed a mathematical model to assess its potential effectiveness.

Microbubbles loaded with drug can easily be added to the bloodstream. The key challenge lies in guiding the microbubbles through the lining of blood vessels so that they may deliver the drug at particular sites where cancer is present. Sonoporation, the subjection of the microbubbles to a localised high frequency signal, is one potential method of achieving this. Essentially, the force generated through sonoporation can create ‘gaps’ in the lining of the blood vessels, providing a doorway to the tumour.

Current microbubbles contain a protein shell. We hypothesised that an entirely different type of material – liquid crystal- may make for a more suitable candidate for localised drug delivery. Liquid crystals exhibit both liquid and solid like-characteristics. The unique material properties of the shell make the microbubble distinctly different from current commercial shelled microbubbles.

Our mathematical model for the sonoporation of a liquid crystalline microbubble considers how the various physical material parameters of the shell either enhance or diminish the wall shear stress. We have compared and contrasted our findings with a typical commercial shelled microbubble and have discovered that liquid crystalline shelled microbubbles may significantly enhance the wall shear stress by up to two orders of magnitude. This implies that our proposed new type of shelled microbubble may be much more effective at sonoporation than the commercial UCAs that are currently under study. Our findings have been published in the journal Ultrasonics [1]

[1] James Cowley and Sean McGinty (2019) A mathematical model of sonoporation using a liquid-crystalline shelled microbubble, Ultrasonics, 96:214-219, https://doi.org/10.1016/j.ultras.2019.01.004.