A new photoactive water-soluble polypropylene imine dendrimer modified with 1,8-naphthalimide and N-glucosamine for light-driven self-sterilizing cotton fabrics

Abstract

Antimicrobial photodynamic therapy is one of the effective strategies for facing the resistance of pathogenic microorganisms of traditional antibiotics. In connection with this, new effective compounds are being sought, increasing their biological activity upon irradiation. In this work, a new polypropylene imine (PPI) from the first generation was synthesized and modified with 1,8-naphthalimide, to which a sulfonyl chloride group (D1) was introduced at the C-4 atom, from which after interaction with glucosamine, a dendrimer containing a sulphonamide group (D2) was obtained. The photophysical characteristics of dendrimer D2 were investigated in five organic solvents of different polarity and aqueous media. It was found that the absorption and fluorescence maxima are slightly affected by the polarity of the solvents. Excimer and monomeric fluorescence were also recorded with dendrimer D2 in an aqueous solution. Dendrimer D2 was deposited on the surface of the cotton fabric, and its release from the cotton fabric was studied for 4 h in a phosphate buffer at 37 °C. The antimicrobial activity of dendrimer D2 was investigated in meat-peptone broth (MPB) against Gram-positive B. cereus and Gram-negative P. aeruginosa and on cotton fabric compared in the dark and after irradiation with sunlight. It has been found that after irradiation with light, the activity of D2 and cotton fabrics is enhanced due to their antimicrobial photodynamic activity. Additionally, light can be utilized to self-sterilize cotton fabrics when treated with D2.