Patterning Cells with Sound

Dr James Armstrong, Bristol University, Autumn 2023

In September 2023, we held a three-day event entitled “TCESNet Summer School: Patterning Cells with Sound” in which we taught nine participants how to design, build and apply ultrasound devices to remotely manipulate cells. Acoustic cell patterning was a biotechnology that I developed for engineering structured musculoskeletal tissues during my time at Imperial College London. The concept is that unlabelled, living cells in an ultrasound standing wave can experience an acoustic radiation force that can rapidly push them towards the acoustic pressure nodes – an effect that can be used to create geometric cell arrays.

These patterned cell populations can then be captured in different biomaterials and used to engineer structured tissue constructs (e.g., Armstrong et al. “Engineering Anisotropic Muscle Tissue using Acoustic Cell Patterning” Advanced Materials 2018; Armstrong et al. “Tissue Engineering Cartilage with Deep Zone Cytoarchitecture by High-Resolution Acoustic Cell Patterning” Advanced Healthcare Materials 2022). I am now continuing to develop this technology and apply it to different tissues in my laboratory at the University of Bristol (www.TheArmstrongGroup.co.uk).

The idea behind this summer school event came during the TERMIS meeting in Manchester in March 2023. After presenting our latest work in this area, I was approached by a number of academics that were interested in applying this method to their own experiments. While the technique is reasonably simple to operate and the components are not restrictively high cost, the need to design and assemble your own devices has acted as a technical barrier to entry for those wishing to use this method. 

A summer school thus seemed to be the perfect opportunity to train up a cohort of individuals all at once and to potentially kick-start some exciting new research projects. Things moved very quickly from this point onwards: I applied for TCESNet funding in April 2023, received a positive outcome in June 2023, advertised on social media over the summer and held the event in the middle of September 2023. The funding provided by TCES allowed us to purchase some basic consumables that we needed to run the event as well as lunchtime catering for the three days.

We were delighted to welcome participants from a breadth of UK universities (Cambridge, Surrey, Oxford, Bristol, Imperial) and companies (QinetiQ), as well as two registrants from European universities (Basque, Aachen).

We started off with the participants giving short presentations about themselves and what they hoped to gain from the summer school. We then moved onto a series of fantastic short talks from Dr Luke Cox “Principles of acoustic patterning”, Dr Madeline Nichols “Acoustic microfabrication of soft materials”, Ricky Hunter “Patterning active matter” and Alex Doulah “Acoustic patterning the glomerulus.” We then had a keynote address from Prof. Bruce Drinkwater on the subject of “Acoustic tweezing: current and future possibilities.”

This half-day of talks were intended to provide a fundamental grounding in the principles of acoustic manipulation and provide inspiration for how the participants’ might apply these methods to their own work.

During the rest of the summer school, we provided hands-on training in how to design, build and test an acoustic cell patterning devices, and how to pattern cells in two different biomaterials (GelMA and fibrin) and how to set up patterning within a sterile tissue culture environment. For these training sessions, we split into groups of three and worked in rotating groups led by myself and two members of my group (Dr Aya Elghajiji, Martha Lavelle).

This allowed us to have very focussed and interactive sessions with plenty of opportunity for hands-on device building and operation. At the end of the summer school, the participants were fully trained up and each left with their own acoustic patterning device that they had built themselves. Surprisingly (given the perverse nature of science!) the event went without any hitch and the feedback we received from participants was overwhelmingly positive.

It was fantastic to see so many people interested in using the technique and in particular the diversity of proposed applications, including some ideas that I had never previously considered. This event very much fuelled my desire to get this technology out of my own laboratory and into the hands of scientists across the UK and beyond. We are now looking to set up an online community to support those that are interested in using this technique, and if there was enough interest, we would be very interested in hosting another similar event in the future. We would like to extend our thanks to TCESNet for enabling and promoting this event and to our invited speakers for their contribution.