Antimicrobial medicine and food packages based on bio-based film containing essential oils have attracted great attention worldwide. However, the controlled release of essential oils from these film nanocomposites is still a big challenge. In this study, a long-term antibacterial film nanocomposite composed of zein film and cinnamon essential oil (CEO) loaded MCM-41 silica nanoparticles was prepared. The CEO was loaded into MCM-41 particles via modified supercritical impregnation efficiently with a high drug load (>40 wt%). The morphologies of the prepared nanoparticles and film nanocomposite were characterized by a scanning electron microscope. The release behaviors of CEO under different temperatures, high humidity, continuous illumination and in phosphate buffer solution (PBS) solution were investigated. The results showed that the film nanocomposite had an outstanding release-control effect. The addition of MCM-41 nanoparticles also improved the mechanical properties of zein films. The antibacterial effect of CEO was significantly prolonged by the film nanocomposite; indicating the CEO film nanocomposite fabricated via modified supercritical CO2 impregnation was a potential long-term antibacterial medicine or food package material.

Biocompatible skin wound dressing materials with long-term therapeutic windows and anti-infection properties have attracted great attention all over the world. The cooperation between essential oil and non-toxic or bio-based polymers was a promising strategy. However, the inherent volatility and chemical instability of most ingredients in essential oils make the sustained pharmacological activity of essential oil-based biomaterials a challenge. In this study, a kind of film nanocomposite loaded with patchouli essential oil (PEO-FNC) was fabricated. PEO-loaded mesoporous silica nanoparticles (PEO-MSNs) with drug load higher than 40 wt% were firstly prepared using supercritical CO2 cyclic impregnation (SCCI), and then combined with the film matrix consisting of polyvinyl alcohol and chitosan. The morphology of PEO-MSNs and PEO-FNC was observed by transmission and scanning electron microscope. The mechanical properties, including hygroscopicity, tensile strength and elongation at break (%), were tested. The release behavior of PEO from the film nanocomposite showed that PEO could keep releasing for more than five days. PEO-FNC exhibited good long-term (>48 h) antibacterial effect on Staphylococcus aureus and non-toxicity on mouse fibroblast (L929 cells), making it a promising wound dressing material.

Introduction: The amentoflavone (AMF) loaded polymeric sub-micron particles were prepared using supercritical antisolvent (SAS) technology with the aim of improving the anticancer activity of AMF. Materials and Methods: Zein and phospholipid mixtures composed of hydrogenated phosphatidylcholine (HPC) and egg lecithin (EPC) were used as carrier materials and, the effects of carrier composition on the product morphology and drug release behavior were investigated. When the mass ratio of Zein/HPC/EPC was 7/2/1, the AMF loaded particles were spherical shape and sub-micron sized around 400 nm, with a drug load of 4.3±0.3 w% and entrapment efficacy of 87.8±1.8%. The in vitro drug release assay showed that adding EPC in the wall materials could improve the dispersion stability of the released AMF in an aqueous medium, and the introduction of HPC could accelerate the drug release speed. Results: MTT assay demonstrated that AMF-loaded micron particles have an improved inhibitory effect on A375 cells, whose IC50 was 37.39μg/ml, compared with that of free AMF(130.2μg/ml). Conclusion: It proved that the AMF loaded sub-micron particles prepared by SAS were a prospective strategy to improve the antitumor activity of AMF, and possibly promote the clinical use of AMF preparations.