A pH-responsive supramolecular polymer gel as an enteric elastomer for use in gastric devices

Abstract

Devices resident in the stomach --which are used for a variety of clinical applications including nutritional modulation for bariatrics, ingestible electronics for diagnosis and monitoring, and gastric retentive dosage forms for prolonged drug delivery --typically incorporate elastic polymers to compress the devices during delivery through the esophagus and other narrow orifices in the digestive system. However, in the event of accidental device fracture or migration, the nondegradable nature of these materials risks intestinal obstruction. Here, we show that an elastic, pHresponsive supramolecular gel remains stable and elastic in the acidic environment of the stomach but can be dissolved in the neutral-pH environment of the small and large intestines. In a large Users may view, print, copy, and download text and data-mine the content in such documents, for the purposes of academic research, subject always to the full Conditions of use

In vivo gastrointestinal drug-release monitoring through second near-infrared window fluorescent bioimaging with orally delivered microcarriers

“…In contrast, the 1,000-nm microcarriers used in our protein delivery experiments exhibited many advantages as good oral drug carriers, such as extended retention times reaching 72 h and minimal deposition (<0.1%) in the visceral organs. The long retention behaviour of the drug carrier can be exploited for prolonged drug delivery systems, which have more flexibility in their dosage design than conventional drug delivery systems48. In addition, we also noticed that the mice in our experiments did not show any signs of discomfort and that their weight gain was normal (average weight increase of ∼200% after three months).…”

Designing hydrogels for controlled drug delivery

“…The extent of swelling of a hydrogel is a balance between forces that constrain network deformation and the osmosis that leads to water absorption 126,127 . The swelling behaviour can be sensitive to various external conditions, including temperature 128 , glucose 129,130 , pH 131 , ionic strength 132 , light 120 , and electric fields 133 . These cues have been widely exploited in drug delivery.…”

Biomimicry, Biofabrication, and Biohybrid Systems: The Emergence and Evolution of Biological Design

“…Langer and co-workers have developed a supramolecular polymer gel, combining poly(acryloyl-6-aminocaproic acid) and poly(methacrylic acid-co-ethyl acrylate), capable of tunable elasticity in response to an external pH stimulus. [30] These gels retain their morphology and elasticity at acidic pH levels, as found in the stomach, and dissolve in neutral pH environments, as found Adv. Healthcare Mater.…”

“…[31] They have engineered a device that is swallowed as a capsule and unfolds into a star-shaped structure in the stomach, allowing for prolonged gastric residence by preventing passage through the pylorus. [134] After delivering drugs over a period of several weeks, the pH-responsive components of the star-shaped structure dissolve, allowing safe passage through the intestines.…”