Researchers pioneer method for measuring the stiffness of liver tissues without damage

Researchers pioneer method for measuring the stiffness of liver tissues without damage

Researchers in South Korea have developed an organoid disease model and non-destructive stiffness analysis technology to evaluate the effectiveness of new drugs for fatty liver disease.

That from Dr. Hyunwoo Kim and Dr. Myungae Bae from Korea Research Institute of Chemical Technology (KRICT) led the research team developed the nano-probe-based quantitative stiffness measurement technique to minimize the artificial organoid model while minimizing the damage to the tissues.

Nonalcoholic fatty liver disease occurs when excess fat builds up in liver cells from overeating or lack of exercise, making the liver softer. Over time, the condition can lead to fibrosis, cirrhosis and ultimately life-threatening diseases such as liver cancer. Therefore, it is crucial to identify effective treatments in the early stages of fatty liver disease in drug development for liver diseases.

Drug development for liver disease involves repeated testing of candidate drugs against disease-causing organoids and analysis of their responses. In particular, the physical stiffness of liver tissues is useful manufacturer, indicating the progress of NAFLD. However, continuous and in-situ measurements of their stiffness are challenging because current measurement methods rely mainly on the entire organoid area until destruction.

The research team has developed a technique that enables non-destructive and in situ measurement of liver organoids modeled with fatty liver disease while maintaining them alive. By applying some nano-Newton forces to the probe-organoid interface using nano-probes, the team was able to quantitatively measure the localized stiffness without damaging the organoid.

To demonstrate the feasibility of the nano-probe-based local stiffness measurement technique, they stained the artificial organoid with a dye to identify high-fat rich/poor regions where strong/weak fluorescence intensities are observed.

For stiffness measurement, “nano-probe” was slowly inserted into organoid tissue using a nanometer-sized tip attached to a tiny cantilever.

The degree of bending of the nano-probe while squeezing the organoid was accurately measured by laser reflection on the probe surface. By correlating the degree of bending to stiffness, the quantified stiffness value was obtained as parameterized in Young's modulus.

Unlike traditional methods that required chemical fixation that killed the organoid, the new nano-probe technique allows “live” measurements while maintaining the viability of the organoid in culture media. By applying a shallow indentation of approximately 5 microns, the method does not damage liver tissue at all.

Applying the newly developed “nano-probe stiffness measurement technology” to non-alcoholic fatty liver organoid models revealed that the stiffness of fat-accumulated regions was approximately 35% softer compared to areas with weak fluorescence. This confirms the ability to precisely target specific regions.

Using fluorescence imaging of lipid accumulation to determine measurement sites reduced the total measurement time by more than half compared to random sampling methods. In addition, liver cell viability was maintained at over 97% after measurement, showing minimal tissue damage.

In the future, the research team aims to develop a continuous drug evaluation system that allows non-destructive monitoring of disease progression in a single organoid across multiple stages.

The research team explained: “This technology enables convenient analysis of disease model changes during fatty liver drug development. Krict President Lee Young-Kook added.” We expect this technology to be applicable not only to the development of liver diseases but also to other advances in disease treatment.“

Sources: