Differences in Zwitterionic Sulfobetaine and Carboxybetaine Dextran-Based Hydrogels

Area of Science:

• Materials Science
• Polymer Chemistry
• Biomedical Engineering

Background:

• Zwitterionic sulfobetaine (SB) and carboxybetaine (CB) compounds are known for antifouling properties.
• Differences between SB and CB materials, particularly zwitterionic polysaccharides, are understudied.
• Molecular simulations offer insights into structure-property relationships.

Purpose of the Study:

• To design and compare sulfobetaine dextran (SB-DEX) and carboxybetaine dextran (CB-DEX) hydrogels.
• To investigate the distinct properties arising from SB and CB functional groups in dextran hydrogels.
• To evaluate the potential of these zwitterionic hydrogels as drug delivery systems.

Main Methods:

• Synthesis of zwitterionic sulfobetaine and carboxybetaine dextran hydrogels.
• Characterization of hydrogel properties including equilibrium swelling ratio and pore size.
• Rheological analysis to determine mechanical properties.
• In vitro drug release studies under acidic conditions.

Main Results:

• SB-DEX hydrogels demonstrated significantly higher equilibrium swelling ratios and larger internal pores compared to CB-DEX hydrogels.
• SB-DEX hydrogels exhibited a lower rheological storage modulus due to increased water content.
• Both SB-DEX and CB-DEX hydrogels showed excellent biocompatibility.
• Sustained release of doxorubicin (DOX) was observed from both hydrogel types at pH 5.0.

Conclusions:

• The distinct chemical structures of SB and CB groups lead to significant differences in dextran hydrogel properties, including swelling, porosity, and mechanical characteristics.
• Zwitterionic dextran hydrogels possess favorable biocompatibility and controlled drug release capabilities, particularly under acidic conditions.
• These findings highlight the potential of SB and CB zwitterionic polysaccharides as advanced materials for biomedical applications, including drug delivery.