Our laboratory invents noninvasive microsurgical devices that operate on organs without having to cut through tissue. These procedures would be pain-less and infection-free techniques; and enable therapeutic and diagnostic capabilities never achieved before. Using a bottom-up research strategy, we study the physics of how non-invasive energies interact with tissue, invent technologies that control these interactions, and then package the technologies into purpose-designed devices. Once a device has developed far enough, we translate the device into medical use - treating, diagnosing, and understanding diseases.
A Capillary Permeabilisier for Drug Delivery
We are developing a technology that can noninvasively and locally deliver drugs to diseased regions. This is achieved by using ultrasound and sonosensitive particles to locally alter the permeability of capillaries in different organs. We have performed initial proof of concept studies in vitro and in vivo; and are now pushing this technology towards clinical trials. If successful, we'll sort through a decade worth of powerful drugs that have been shelved due to poor permeability, and deliver them noninvasively and locally to where they are needed. This technology is being developed for the treatment of paediatric brain cancer and Alzheimer's disease.
An Acoustic Micropump for Drug Enhancement
By using ultrasound alone, we can enhance the distribution of drugs through tissue microenvironments. We are developing methods to enhance the distribution of molecules and nanoparticles. This technology is being developed for a range of diseases that includes cancer.
An Acoustic Particle Palpator for Measuring Tissue Elasticity
Devices and methods are also being developed to push tissue and track its displacement and relaxation to determine stiffness. This elasticity imaging technique provides a quantitative measure of a property, which has been linked to the progression of several diseases. This technology is being developed for early detection of liver diseases, such as liver fibrosis and hepatocellular carcinoma.
How it Works
Sound has the unique property of traveling through materials, which is the reason you can often hear your neighbour through opaque walls. Higher sound frequencies attenuate through the wall more so than lower frequencies. This is why you can hear lower tones from sources such as subwoofers.
In biomedical acoustics, very high frequencies known as ultrasound (0.25 to 10 MHz) are focused through several layers of tissue to converge to a small focal volume. This limits ultrasound-induced effects to a confined area while not affecting the surrounding healthy tissue. Ultrasound has unique properties when compared to other kinds of energy (e.g., light, magnetism):
Deep penetration (several centimetres)
Localisation (safety below certain intensities has been established)
Ultrasonically Generated Forces Triggers Biological Effects
The focus of our laboratory is to functionally alter or probe biological tissue in a way that (1) is safe and temporary and (2) controllable at the micron- and nano-scale. We do NOT research high-intensity focused ultrasound (HIFU) or lithotripsy, which both use ultrasound to destroy tissue. In fact, we use pulse sequences, which more closely resemble ultrasound imaging pulses, which have an established safety profile. By carefully designing ultrasonic pulse sequences, we generate a wide range of ultrasonic phenomena within the focal volume:
Heating (mild levels)
Our laboratory has an in-depth understanding of how the physics and biology are interacting with each other. We have the necessary balance of engineering, physics, and biology. Thus our manipulation and probing techniques are not limited to the size of the focal volume, but can be refined down to molecular and cellular behaviours through compartmentalisation of the phenomena (e.g., vascular, interstitial, and cellular compartments) and the use of sono-sensitive nano- and micro-particles (e.g., expansion and contraction of a microbubble). We can produce a range of safe and reversible bioeffects:
Increased vascular permeability
Increased cell membrane permeability
Displacement of fluid
Displacement of tissue