Design of pH-responsive antimicrobial nanocomposite as dual drug delivery system for tumor therapy

A novel antibacterial clay/polymer nanocomposite with average particle size of 20-40 nm and two cationic compartments in polymer was synthesized via ion exchange. The structure of the nanocomposites was characterized by XRD, FT-IR, TG-DTA, and SEM. This multifunctional nanocomposite was used for dual drug delivery of anticancer drug methotrexate (MTX) and an antibacterial agent ciprofloxacin (CIP) with encapsulation efficiency of > 90% for both drugs. The in vitro antimicrobial activity of the clay/polymer nanocomposites was studied against Escherichia coli and Pseudomonas aeruginosa bacteria by a well diffusion method. The nanocomposite showed good or moderate antimicrobial activities. However, CIP loaded nanocomposites showed enhanced antimicrobial activity in comparison to free CIP. The potential antitumoral activity of this clay/polymer nanocomposite system was evaluated against MCF7 cell lines by MTT assay and cell cycle studies. The cytotoxicity studies demonstrated enhanced cytotoxicity of developed MTX loaded nanocomposite in comparison to free MTX. Cell cycle study showed that MTX-loaded nanocomposite caused S-phased arrest in MCF-7 cells compared to control non-treated cells (P < 0.001). Therefore, dual drug-loaded antibacterial nanocomposite has the potential to be used for cancer therapy.