Design and Synthesis of Six‐Armed Antimicrobial Polymer to Battle Against Nosocomial Pathogens

ABSTRACT The world is under threat from microorganisms that have evolved resistance to currently available medicinal drugs and multidrug resistance among bacterial pathogens is becoming to be a serious public health issue worldwide. It is imperative to find or develop new antibiotics against Enterococcus faecium , Staphylococcus aureus , Klebsiella pneumoniae , Acinetobacter baumannii , Pseudomonas aeruginosa , and Enterobacter species (ESKAPE) pathogens because they exhibit multidrug resistance and virulence through a variety of mechanisms. ESKAPE infections are often associated with increased global healthcare costs, morbidity, and illnesses. As a result, the utilization of naturally occurring bioactive agents offers a solution since these molecules are widely available and safe to employ during their use. Ricinoleic acid, an extract of seed oil that contains an unsaturated omega‐9 fatty acid and hydroxy acid, has garnered increasing interest due to its wide‐range antibacterial properties. Herein, we report the synthesis of polyethyleneimine‐ricinoleic acid‐based polymer (PEIRA) to battle against Methicillin‐resistant Staphylococcus aureus (MRSA), Acinetobacter baumannii (one among ESKAPE) and Staphylococcus aureus . The synthesized polymer showed efficient activity against MRSA, Acinetobacter baumannii , and Staphylococcus aureus . A noticeable percentage inhibition against MRSA (74%), A . baumannii (73%), and S . aureus (81%) was achieved at 2.5 mg/mL. The time‐kill assay revealed that the PEIRA polymer exhibited a bacteriostatic effect against all the tested pathogens. Cytotoxicity assay on human dermal fibroblast (HDF) cell lines revealed the PEIRA has an IC 50 of 31.7 μg/mL and exhibited above 75% cell viability at the concentration 5 and 10 μg/mL were deemed nontoxic on HDF. Based on the investigation, the synthesized PEIRA polymer may have promising applications in the biomedical sector and hospital‐acquired infections (HAIs).