Antimicrobial sponge prepared by hydrophobically modified chitosan for bacteria removal

Area of Science:

• Biomaterials Science
• Environmental Engineering
• Microbiology

Background:

• Chitosan is a biocompatible polysaccharide with inherent antimicrobial properties.
• Developing advanced materials for efficient bacterial removal from aqueous solutions is crucial.
• Hydrophobic modification can enhance the functionality of chitosan-based materials.

Purpose of the Study:

• To synthesize and characterize hydrophobically modified chitosan (HMCS) sponge.
• To evaluate the efficacy of HMCS sponge in capturing and inactivating Escherichia coli (E. coli).
• To assess the reusability and operational stability of HMCS sponge for bacterial removal.

Main Methods:

• HMCS was prepared by reacting chitosan with dodecyl aldehyde.
• Stable HMCS foam was generated and freeze-dried to produce a lightweight sponge.
• Bacterial capture capacity, cell viability, and release were quantified.
• Regeneration and stability of the HMCS sponge were tested over multiple cycles.

Main Results:

• HMCS sponge exhibited a high density of 32 mg/ml and excellent foam stability.
• The sponge demonstrated significant E. coli capture capacity (∼4.0 × 10^8 cells/mg).
• Captured E. coli cells were predominantly dead, and easily released, allowing for surface regeneration (>90% capacity after 5 cycles).

Conclusions:

• HMCS sponge is a promising material for efficient and reusable bacterial removal.
• The hydrophobic dodecyl chains enhance E. coli capture and inactivation.
• HMCS sponge offers superior operational stability compared to unmodified chitosan sponge.