Ingestible hydrogel device

Xinyue Liu,Christoph Steiger,Hyunwoo Yuk,Giovanni Traverso,Shaoting Lin,Siddartha Tamang,Nhi V Phan,Joy Collins,Ji Liu,Hon Fai Chan,Xuanhe Zhao,German Alberto Parada

doi:10.1038/s41467-019-08355-2

Abstract

Devices that interact with living organisms are typically made of metals, silicon, ceramics, and plastics. Implantation of such devices for long-term monitoring or treatment generally requires invasive procedures. Hydrogels offer new opportunities for human-machine interactions due to their superior mechanical compliance and biocompatibility. Additionally, oral administration, coupled with gastric residency, serves as a non-invasive alternative to implantation. Achieving gastric residency with hydrogels requires the hydrogels to swell very rapidly and to withstand gastric mechanical forces over time. However, high swelling ratio, high swelling speed, and long-term robustness do not coexist in existing hydrogels. Here, we introduce a hydrogel device that can be ingested as a standard-sized pill, swell rapidly into a large soft sphere, and maintain robustness under repeated mechanical loads in the stomach for up to one month. Large animal tests support the exceptional performance of the ingestible hydrogel device for long-term gastric retention and physiological monitoring.

Highlights

Devices that interact with living organisms are typically made of metals, silicon, ceramics, and plastics
The ideal hydrogel device needs to swell in the gastric environment from an orally administered pill to a size large enough to avoid passing through the pylorus[17], and fast enough to avert gastric emptying, which generally occurs 0.5–1.5 h after ingestion[18]
Tough hydrogels have been used for gastric retention[10], but their low swelling speed presents a challenge for clinical development

Summary

Introduction

Devices that interact with living organisms are typically made of metals, silicon, ceramics, and plastics. We introduce a hydrogel device that can be ingested as a standard-sized pill, swell rapidly into a large soft sphere, and maintain robustness under repeated mechanical loads in the stomach for up to one month. The hydrogel device can be ingested as a standard-sized pill (diameter of 1–1.5 cm), rapidly imbibe water and inflate (up to 100 times in volume within 10 min) into a large soft sphere (diameter of up to 6 cm, modulus of 3 kPa), and maintain robustness under repeated mechanical loads over a long time (more than 26,000 cycles of 20 N force over 2 weeks in vitro). This ingestible and gastric-retentive hydrogel device possesses a set of advantages over conventional ingestible devices made of other materials due to hydrogels’ biocompatibility, high water content, and tissue-like softness[1,3,16]

Methods

Results

Conclusion