Ingestible hydrogel device

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.

Muscle-like fatigue-resistant hydrogels by mechanical training

“…Moreover, despite their high water content of around 75 wt % (3), skeletal muscles can sustain a high stress of 1 MPa over 1 million cycles per year, with a fatigue resistance over 1,000 J/m 2 (4). The combinational properties of skeletal muscles (i.e., high fatigue resistance, high strength, superior compliance, and high water content) are highly desirable for hydrogels' nascent applications in soft biological devices, such as load-bearing artificial tissues (5), hydrogel bioelectronics (6)(7)(8)(9), hydrogel optical fibers (10,11), ingestible hydrogel devices (12), robust hydrogel coatings on medical devices (13)(14)(15)(16)(17), and hydrogel soft robots (18)(19)(20).…”

Biohybrid Design Gets Personal: New Materials for Patient‐Specific Therapy

“…Liu et al, inspired by the defensive response of pufferfish, used PAA as the basis for a fast‐swelling gastro‐retentive implantable device . Pufferfish stomachs are highly elastic and, when the fish are confronted by predators, can be rapidly filled with water and inflated to a spherical form that proves dangerous and hard to digest.…”

“…a) Pufferfish‐inspired design of a rapidly inflating hydrogel device designed for gastric residence. Adapted with permission . Copyright 2019, Springer Nature.…”

Retentive drug delivery systems based on shape memory materials

“…Expansion‐dependent retention tools also underlie a number of cutting‐edge engineered devices, and related construction materials, aimed at gastric residence times beyond 24 h up to several weeks . In this respect, star‐shaped and spherical fenestrated structures, subject to in situ reversible expansion due to elastic unfolding, and a pufferfish‐like hydrogel system having high‐speed, high‐ratio, and durable water swelling have been described, for human and/or veterinary application . All of them would notably match the "Ultra‐long‐acting oral formulation" category of FDA's Emerging Technology Program, which has been launched by the agency to endorse adoption of innovative pharmaceutical design and manufacturing schemes entailing purposely set regulatory evaluation approaches .…”