DEAE/Catechol-Chitosan Conjugates as Bioactive Polymers: Synthesis, Characterization, and Potential Applications.

Area of Science:

• Biomaterials Science
• Polymer Chemistry
• Nanotechnology

Background:

• Chitosan (Cs) is a biocompatible polysaccharide with inherent antimicrobial properties.
• Modifications are needed to enhance chitosan's solubility and antioxidant capacity for broader applications.

Purpose of the Study:

• To synthesize and characterize novel water-soluble chitosan derivatives (Cs-DC) by conjugating diethylaminoethyl (DEAE) and catechol groups.
• To evaluate the antioxidant, antimicrobial, and cytotoxic properties of the synthesized Cs-DC.
• To develop and characterize multifunctional nanoparticles from Cs-DC.

Main Methods:

• Synthesis of chitosan-DEAE-catechol (Cs-DC) derivatives.
• Spectroscopic analysis (degree of substitution), X-ray diffraction, and thermogravimetric analysis for characterization.
• Antioxidant activity assays (EC50), antimicrobial tests, and cytotoxicity assessments.
• Nanoparticle formation via ionotropic gelation and hyaluronic acid coating.

Main Results:

• Successful synthesis of Cs-DC with DEAE (35.46%) and catechol (2.53%) substitution.
• Increased water solubility at pH > 7, maintained antimicrobial activity, and enhanced radical scavenging capacity.
• Cs-DC derivatives exhibited low cytotoxicity and reduced reactive oxygen species by 40% at 4 μg/mL.
• Stable, ~200 nm multifunctional nanoparticles with narrow size distribution and negative ζ-potential were produced.

Conclusions:

• The novel Cs-DC derivatives possess combined antioxidant and antimicrobial properties with improved solubility and low cytotoxicity.
• The developed multifunctional nanoparticles demonstrate enhanced stability and potential for biomedical applications.
• This work presents a promising strategy for developing advanced chitosan-based biomaterials.