Sustainable Cyclodextrin Modification and Alginate Incorporation: Viscoelastic Properties, Release Behavior, and...

Area of Science:

• Materials Science
• Biotechnology
• Polymer Chemistry

Background:

• Ionically crosslinked polysaccharide matrices, like alginate hydrogels, are promising for carrier systems.
• Cyclodextrins (CDs) can be incorporated to enhance matrix properties, but compatibility can be an issue.
• Tuning rheological properties and ensuring biocompatibility are key for effective carrier systems.

Purpose of the Study:

• To develop modified cyclodextrins (CDs) for improved compatibility with alginate hydrogels.
• To investigate the impact of modified CDs on hydrogel properties, including gelation kinetics and rheology.
• To assess the controlled release and retention of modified CDs within alginate microbeads.

Main Methods:

• Solvent-free synthesis of citric acid-functionalized (CDC) and maleic anhydride-functionalized (CDM) β-cyclodextrins.
• Characterization of modified CDs using FTIR, 1H NMR, DLS, zeta potential, and MS.
• Rheological analysis of alginate hydrogels incorporating native and modified CDs.
• Fabrication of alginate microbeads via vibrational prilling and assessment of CD retention and release.

Main Results:

• Successful esterification of β-cyclodextrin with citric acid and maleic anhydride confirmed.
• Modified CDs (CDC, CDM) delayed alginate gelation and reduced gel strength compared to native CDs.
• Alginate microbeads exhibited controlled size (800-1000 µm) and high CD retention (>80% after 28 h).
• Modified CDs showed slightly greater release rates than native CDs.

Conclusions:

• Solvent-free modification of CDs offers a sustainable method to tailor alginate hydrogel properties.
• Modified CDs effectively modulate gelation kinetics, viscoelasticity, and release behavior.
• This approach provides a versatile, food- and health-compliant platform for controlled delivery applications.