pH-Sensitive Fluorine-Containing Hydrogel System for Enhanced Intestinal Computed Tomography Imaging.

Area of Science:

• Biomaterials Science
• Radiology
• Drug Delivery

Background:

• Iohexol (IOH) is a nonionic contrast agent with limitations in intestinal CT imaging due to poor retention.
• Current contrast agents face challenges with prolonged circulation and inadequate gastrointestinal retention.

Purpose of the Study:

• To develop an intestinal-targeting system for improved oral nonionic contrast agent delivery.
• To enhance the effectiveness of iohexol for intestinal CT imaging.

Main Methods:

• Development of pH-sensitive hydrogels encapsulating perfluorocarbon droplets for iohexol delivery.
• Evaluation of structural stability using temperature-responsive phase transitions.
• Assessment of iohexol release profiles in simulated gastric (pH 1.2) and intestinal (pH 7.4) fluids.
• Testing of cellular CT contrast enhancement and cell morphology preservation.

Main Results:

• The hydrogel system showed minimal iohexol release (9%) in simulated gastric fluid within 60 minutes.
• Rapid and significant iohexol release (80% in 30 minutes) was observed in simulated intestinal fluid (pH 7.4).
• The formulation enhanced cellular CT contrast without altering cell morphology.

Conclusions:

• The developed intestinal-targeting system effectively delivers iohexol with pH-dependent release characteristics.
• This system shows potential as an improved oral nonionic contrast agent for diagnosing intestinal diseases.
• Perfluorocarbon-encapsulated hydrogels offer enhanced structural stability and targeted drug release.