One-pot synthesis of tunable fluorescent polyethylene glycol (PEG) polymer for antimicrobial and anticancer theranostics

Poly (ethylene glycol) (PEG), is a well-known biocompatible and biodegradable polymer with a wide range of applications such as surface coating of nano/micro materials for improving their biocompatibility, immunological inertness, and systemic circulation. However, PEG is a nonfluorescent material limiting its application in bioimaging. So herein, a novel fluorescent PEG polymer was synthesized using a facile method. For this, in-house water-soluble compound [4,5-bis-{(N- carboxy methyl benzimidazolium) methyl} acridine] dibromide}] (b-ACA) was synthesized and used to modify nonfluorescent PEG polymer into a novel fluorescent PEG polymer (PEG-b-ACA) by one-pot method. PEG-b-ACA displayed a range of fluorescence from green to red with respect to the concentration of b-ACA being used. The synthesized PEG-b-ACA mixture was evaluated for its antimicrobial and antiviral efficacy against E. coli, S. aureus, C. albicans, and Bacteriophage Lambda, and it showed significant inhibition of microbial and viral growth. The mixture was also evaluated for its cellular uptake and anticancer efficacy using 4T1 breast cancer cells, and it showed significant results in both. The results demonstrated that the PEG-b-ACA mixture is a potent antimicrobial, antiviral, and anticancer agent when compared with PEG and b-ACA alone. Therefore, the synthesized PEG-b-ACA mixture could be an effective material for various biomedical applications.