by Lucas Johnson, Vanderbilt University

Wirelessly controlled millimeter-scale soft capsules for local liquid sampling in deep, tight and tortuous body sites. Credit: Science Advances (2024). DOI: 10.1126/sciadv.adp2758

Vanderbilt researchers have developed technology for sampling body liquids in tortuous and narrow spaces that could lead to early detection of diseases like cancer.

The research led by Xiaoguang Dong, assistant professor of mechanical and biomedical engineering, and his team was recently featured in Science Advances.

Body liquids—such as blood, pancreatic juice, urine, and mucus—are rich resources of information regarding chemical composition, biomarkers, bacteria colonies, and other crucial components. This information helps researchers understand the mechanism of various diseases, such as cancer, and track the health condition of patients.

To collect these liquids, wireless mobile robots at the millimeter scale have proven to be effective in navigating confined spaces because of their diminutive size and agile locomotion. However, the function of sampling liquids is missing in such devices due to the absence of effective triggering and sealing mechanisms at small scales.

Dong and his team have addressed this issue with the creation of millimeter-scale soft capsules featuring hydrogel-and-elastomer hybrids controlled by external magnetic fields. The researchers said such devices could be delivered and retrieved by a thin catheter and adeptly locomote in tubular structures inaccessible to the catheters. The soft capsules have a specifically coated wetting property, allowing them to pump liquids inside efficiently.

The integration of on-demand triggering, sampling, and sealing mechanism and the agile group locomotion has allowed the researchers to demonstrate precise control of the soft capsules, navigating and sampling body fluids in a phantom and animal organ ex vivo, guided by ultrasound and X-ray medical imaging.

"The millimeter-scale soft capsules introduced in this work opens avenues for minimally invasive and targeted liquid biopsy in confined spaces such as the pancreas duct, enabling early disease diagnosis and providing insights into disease development through the sampling, retrieval, and analysis of abundant chemicals within organs," said Dong, who is also a core member of the Vanderbilt Institute for Surgery and Engineering (VISE).

Dong plans to pursue a project about "Wirelessly Actuated Ciliary Stent for Minimally Invasive Treatment of Cilia Dysfunction."

The project aims to develop implantable airway stents with integrated artificial cilia to overcome the limitations of existing stents, such as tissue ingrowth and cilia impairment, and allow for minimally invasive removal of excess mucus in the airway. This innovation addresses the current challenges of excessive mucus accumulation in patients with central airway obstruction due to chronic obstructive pulmonary disease (COPD), lung cancer, cystic fibrosis, and other lung conditions.

More information: Xiaoguang Dong et al, Millimeter-scale soft capsules for sampling liquids in fluid-filled confined spaces, Science Advances (2024). DOI: 10.1126/sciadv.adp2758

Journal information: Science Advances 

Provided by Vanderbilt University