Antibacterial activity of chitosan nanofiber meshes with liposomes immobilized releasing gentamicin

Chitsan (Ch) nanofiber mesh (NFM) is a material with natural characteristics favoring its use in human

wound dressing. The present work proposes a gentamicin-loaded liposome immobilized at the surface

of Ch NFMs to promote its antibacterial activity. To achieve this purpose, Ch NFMs were functionalized

with thiol groups, and gentamicin-loaded liposomes were covalently immobilized by the reaction of

the SH groups with maleimide. The maximum concentration of SH groups (55.52 ± 11.19 nmol cm2)

was obtained at pH 7. A fluorescent dye was covalently bound to the SH groups present at the surface

of electrospun Ch NFMs. Their spatial distribution was uniform throughout the NFMs when analyzed

by fluorescence microscopy. Gentamicin was successfully encapsulated into the liposomes with an efficiency

of 17%. Gentamicin-loaded liposomes were uniformly distributed at the surface of the Ch NFMs

and the drug release kinetic showed a sustained release of gentamicin during 16 h, achieving a steady

state at 24 h. The in vitro susceptibility tests confirmed that the gentamicin released from the liposomes

immobilized at the surface of electrospun Ch NFM has bactericidal activity against Escherichia coli,

Pseudomonas aeruginosa and Staphylococcus aureus. The results show that the developed system has

promising performance for wound dressing applications, avoiding infections caused by these common

pathogens.