Chitosan/organic rectorite nanocomposite films: Structure, characteristic and drug delivery behaviour

Rectorite is a kind of layered silicate, with the structure and characteristic much like those of montmorillonite. It is a regularly interstratified clay mineral with alternate pairs of dioctahedral mica-like layers (nonexpansible) and dioctahedral montmorillonite-like layers (expansible) in a 1:1 ratio. Chitosan/organic rectorite (chitosan/OREC) nanocomposite films with different mass ratios of chitosan to organic rectorite and corresponding drug-loaded films were successfully obtained by a casting/solvent evaporation method. The structures of the films were evaluated by FTIR-ATR, XRD and SEM. A wide variety of material characteristics for the chitosan/OREC nanocomposite films were investigated, including the water resistance, mechanical property, optical transmittance, anti-ultraviolet capacity and bactericidal activity. The characteristics of the nanocomposite films were related to the amount and the interlayer distance of OREC in them. In vitro drug-controlled release studies showed a slower and more continuous release for the nanocomposite films in comparison with pure chitosan film, and the drug-delivery cumulative release was proportional to the amount and the interlayer distance of OREC. The chitosan/OREC nanocomposites films provide promising applications as antimicrobial agents, water-barrier compounds, anti-ultraviolet compounds, and drug-controlled release carriers in antimicrobial food packaging and drug-delivery system.