Chlorin e6 conjugated chitosan as an efficient photoantimicrobial agent

The development of antibacterial agents with high bacteria-binding capability and antibacterial efficiency is highly desirable. Herein, cationic polysaccharide chitosan (CS) was combined with photosensitizer Chlorin e6 (Ce6) to construct a novel photodynamic antibacterial agent (CS-Ce6 conjugates) for combating gram-positive bacteria Staphylococcus aureus (S. aureus) and gram-negative bacteria Escherichia coli (E. coli). CS-Ce6 conjugates with different degrees of substitution (DS) were synthesized and characterized by a spectroscopic method and organic elemental analysis to understand the relationship between structure and antibacterial effect. CS-Ce6 conjugates revealed good reactive oxygen species (ROS) generation ability and photodynamic antibacterial effect. Meanwhile, they both were positively correlated with DS in the range of 4.81% similar to 11.56% resulting in stronger photodynamic antibacterial ability. These findings highlight that CS-Ce6 conjugates have the potential as an effective photodynamic bactericidal agent in the antibacterial field. (C) 2021 Elsevier B.V. All rights reserved.

Automated summary

The study developed a novel photodynamic antibacterial agent CS-Ce6 conjugates by combining cationic polysaccharide chitosan with photosensitizer Chlorin e6 for combating gram-positive and gram-negative bacteria. The results demonstrated that the photodynamic antibacterial effect of CS-Ce6 conjugates was positively correlated with the degree of substitution (DS). This research highlights the potential of CS-Ce6 conjugates as effective photodynamic bactericidal agents.