Alginate hydrogels coated with chitosan for wound dressing

Area of Science:

• Biomaterials Science
• Drug Delivery Systems
• Tissue Engineering

Background:

• Alginate hydrogels are widely used but have limitations in drug release control and antimicrobial properties.
• Chitosan is a biocompatible polymer with known antibacterial activity and mucoadhesive properties.

Purpose of the Study:

• To develop and characterize chitosan-coated alginate hydrogels for enhanced drug delivery.
• To evaluate the antibacterial activity and in vitro toxicity of the coated hydrogels.
• To assess the sustained release of hydrophilic drugs from the coated hydrogels.

Main Methods:

• Alginate hydrogels with varying calcium content were prepared using the internal setting method.
• Hydrogels were coated with chitosan hydrochloride (CH-Cl) via immersion.
• Morphological analysis was performed using cryo-scanning electron microscopy.
• In vitro cytotoxicity was assessed using human mesenchymal stromal cells (MSC).
• Swelling, stability, drug release (rhodamine B), and antibacterial activity (Escherichia coli) were evaluated.

Main Results:

• Chitosan coating altered the hydrogel morphology.
• Chitosan hydrochloride exhibited no cytotoxicity to MSCs.
• Coated hydrogels demonstrated reduced swelling and improved stability in physiological solution.
• Sustained release of rhodamine B was observed from coated hydrogels compared to uncoated ones.
• Effective antibacterial activity against Escherichia coli was confirmed.

Conclusions:

• Chitosan-coated alginate hydrogels offer a promising platform for advanced wound dressings.
• The coating enhances drug release control and provides intrinsic antimicrobial benefits.
• This approach integrates sustained drug delivery with antibacterial efficacy for improved therapeutic outcomes.