Tufts researchers develop smart ingestible pills

Addressing gastrointestinal issues due to pathogenic microbes such as E. coli bacteria can be challenging. Current methods analyze fecal samples, which may not show the presence of the microbe early in the infection. Moreover, those methods cannot identify where along the digestive tract the harmful bacteria was located. Fecal samples provide an overall picture of the digestive system, but don’t provide an accurate assessment of the small intestine microbiome. More accurate methods such as surgery tend to be invasive and expensive. 

In response to this challenge, researchers in Professor Sameer Sonkusale’s NanoLab and colleagues from Tufts’ Cummings School of Veterinary Medicine are developing a non-invasive, novel method of E. coli detection in the small intestine using an ingestible pill. The team recently published its work in Advanced Functional Materials. The group included Sonkusale, lead authors Research Assistant Professor Kawin Khachornsakkul and postdoctoral scholar Ruben Del-Rio-Ruiz, PhD candidate Wenxin Zeng, and postdoctoral scholar Danilo Martins Dos Santos, all from Tufts NanoLab; working alongside research scholar Debora Regina Romualdo da Silva and Professor Giovanni Widmer from the Cummings School of Veterinary Medicine.

Users swallow the pill which travels through their digestive tract. When it reaches the small intestine, the pH-sensitive coating activates the sensor and collects localized samples. The pill is made up of threads that contain fluorescent gold nanoclusters. Each of the threads has specific polymers that act as a receptor for the E. coli bacteria. If the pill captures a sample that includes the target bacteria, it will bind to the polymer and activate the fluorescent thread. The more E. coli found in the sample, the more threads will turn fluorescent.

The pill is designed to provide a low-cost, quick, and accurate analysis of the small intestinal colonization. After collecting the samples, the pill self-seals using hydrophilic beads to ensure that the samples remain localized. On recovery of the pill from the feces, UV light is used to illuminate the pill and the fluorescence intensity data is displayed on a smartphone for easy access and interpretation. While the researchers’ work is specifically focused on E. coli bacteria in the small intestine, the design has the potential to target a range of harmful gastrointestinal infections. Possible uses include rapidly diagnosing gastrointestinal-related medical conditions and studying host-microbiome interactions.

In addition to ingestible pills, researchers in Tufts’ NanoLab use unconventional materials such as paper, textile, or threads to develop smart bandages, surgical sutures, and microneedles. Director Sameer Sonkusale of the Department of Electrical and Computer Engineering and fellow NanoLab researchers prioritize work on interdisciplinary problems with implications for health and the environment. They design miniaturized nano-enabled sensors, low power circuits that can compute at a fraction of a volt, and imagers that can see the invisible terahertz band and even detect fluorescence lifetime, among other things.