Engineering a novel antibacterial agent with multifunction: Protocatechuic acid-grafted-quaternized chitosan

Area of Science:

• Biomaterials Science
• Antimicrobial Agents
• Polymer Chemistry

Background:

• Hydroxypropyltrimethyl ammonium chloride chitosan (HACC) demonstrates efficacy against gram-positive bacteria but lacks activity against gram-negative bacteria.
• Existing antibacterial agents often face challenges with cytotoxicity and resistance development.

Purpose of the Study:

• To enhance the antibacterial spectrum of HACC by grafting protocatechuic acid (PA).
• To evaluate the antibacterial efficacy, antioxidant capacity, anti-inflammatory properties, and cytocompatibility of the novel PA-g-HACC conjugate.

Main Methods:

• Grafting of protocatechuic acid (PA) onto hydroxypropyltrimethyl ammonium chloride chitosan (HACC) to synthesize PA-g-HACC.
• Antibacterial assays were performed against Staphylococcus aureus (S. aureus), methicillin-resistant Staphylococcus aureus (MRSA), and E. coli.
• Antioxidant capacity, anti-inflammatory properties, and cytocompatibility were assessed.

Main Results:

• PA-g-HACC exhibited high antibacterial rates (>92%) against S. aureus and MRSA.
• The antibacterial efficacy against E. coli increased with the grafting ratio of PA.
• PA-g-HACC demonstrated favorable antioxidant and anti-inflammatory properties, with cytocompatibility dependent on the grafting ratio.

Conclusions:

• PA-g-HACC represents a promising antibacterial agent with a broadened spectrum of activity.
• The optimal grafting ratio of PA provides a balance of potent antibacterial effects, pharmacological benefits, and acceptable cytocompatibility.
• PA-g-HACC holds potential for developing novel therapeutic agents to combat bacterial infections.