Poly(3-hydroxybutyrate)/polyethylene glycol-NiO nanocomposite for NOR delivery: Antibacterial activity and cytotoxic effect against cancer cell lines.

Norfloxacin (NOR), a well-known antibacterial agent is also known to have potential antitumor activity. In this study, NOR was immobilized into poly(3-hydroxybutyrate/polyethylene glycol‑nickel oxide (PHB/PEG-NiO) nanocomposites using different NiO contents. The NiO nanoparticles were prepared by sol-gel method and the nanocomposites were prepared by solution cast films. Physicochemical features of nanocomposites were monitored by XRD, FTIR, SEM, TEM and TGA. PHB/PEG-5%NiO nanocomposites showed high NOR loading efficiency (60%) and a long-sustained release in comparison with other carriers. The studies on the adsorption of NOR onto PHB/PEG-NiO nanocomposite revealed that the adsorption process obeyed second order kinetic and Temkin isotherm was applicable to describe the adsorption process. The mechanism of release was studied by using different kinetic equations. The loaded nanocomposites (NOR@PHB/PEG-NiO) showed effective antimicrobial activity towards gram-positive (Staphylococcus aureus), and gram-negative bacteria (E.coli and Klebsiella pneumonia). The in vitro cytotoxicity was conducted on four human cancer cell lines viz., liver Hepatocellular carcinoma, colon cancer cell, prostate cancer cell, and breast adenocarcinoma from human and one normal human amnion cell line using MTT assay. Cytotoxicity results demonstrated that NOR@PHB/PEG-NiO significantly reduced cell viability than free NOR. NOR@ PHB/PEG-NiO has about 2.5-fold more cytotoxicity as compared with free drug with a lack of cytotoxicity against normal cells.