Structurally preserved TEMPO-oxidized succinoglycan enables dual pH/temperature-responsive hydrogels with intrinsic...

Area of Science:

• Biomaterials Science
• Polymer Chemistry
• Materials Engineering

Background:

• Developing stimuli-responsive hydrogels is crucial for advanced drug delivery systems.
• Microbial exopolysaccharides offer unique structural and bioactive properties for biomaterial applications.
• Maintaining the structural integrity and bioactivity of polysaccharides during modification is a significant challenge.

Purpose of the Study:

• To create a multifunctional hydrogel system with dual responsiveness to temperature and pH.
• To utilize TEMPO-oxidized succinoglycan (TEMPO-SG) as a structurally stable, antioxidant matrix.
• To investigate the impact of TEMPO-SG incorporation on hydrogel properties and drug release.

Main Methods:

• Selective oxidation of succinoglycan using TEMPO/NaClO/NaClO2 under mild conditions.
• Copolymerization of TEMPO-SG with poly(N-isopropylacrylamide) (pNIPAM) at varying concentrations.
• Characterization using acid-base titration, FTIR, NMR, rheology, swelling analysis, and in vitro drug release studies.

Main Results:

• TEMPO-SG was successfully synthesized, introducing carboxyl groups while preserving its molecular structure and antioxidant properties.
• Hydrogel mechanical properties, storage modulus, swelling behavior, and gel strength were enhanced with increasing TEMPO-SG content.
• The fabricated hydrogels exhibited dual responsiveness to both temperature and pH, demonstrated by controlled 5-fluorouracil release.

Conclusions:

• Mild oxidation of microbial polysaccharides provides a viable route to engineer antioxidant, stimuli-responsive hydrogels.
• The TEMPO-SG/pNIPAM hydrogel system demonstrates tunable mechanical properties and dual-stimuli responsiveness.
• This novel biomaterial platform holds significant promise for applications in controlled drug delivery, wound healing, and antioxidant biomaterials.