Increasing the Bile Acid Sequestration Performance of Cationic Hydrogels by Using an Advanced/Controlled...

Area of Science:

• Polymer Chemistry
• Biomaterials Science
• Drug Delivery Systems

Background:

• Bile acid sequestrants (BAS) are crucial for managing hyperlipidemia.
• Hydrogels offer potential as effective BAS due to their tunable properties.
• Optimizing hydrogel composition and synthesis is key to enhancing BAS performance.

Purpose of the Study:

• To evaluate the impact of polymerization technique and hydroxyl group content on PAMPMTA-co-PHEA hydrogel performance as BAS.
• To compare the bile acid binding capacity of hydrogels synthesized via free radical polymerization (FRP) and supplemental activator and reducing agent atom transfer radical polymerization (SARA ATRP).
• To assess the in vitro degradation of these novel hydrogels in simulated gastrointestinal environments.

Main Methods:

• PAMPMTA-co-PHEA hydrogels were synthesized using FRP and SARA ATRP.
• Fourier-transform infrared spectroscopy (FTIR) and solid-state nuclear magnetic resonance (ssNMR) confirmed hydrogel structure and composition.
• High-performance liquid chromatography (HPLC) measured sodium cholate binding in simulated intestinal fluid.
• In vitro degradation studies were conducted in simulated gastric and intestinal fluids.

Main Results:

• Increased 2-hydroxyethyl acrylate (HEA) content in hydrogels decreased bile acid binding capacity.
• Hydrogels synthesized via SARA ATRP exhibited significantly higher binding capacity compared to those from FRP.
• PAMPMTA-co-PHEA hydrogels demonstrated excellent stability, showing no degradation in simulated stomach and intestinal environments.

Conclusions:

• SARA ATRP is a superior polymerization technique for developing high-performance BAS hydrogels.
• Hydrogel composition, specifically HEA content, directly influences binding efficacy.
• These novel hydrogels show promise as stable and effective bile acid sequestrants.