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In this paper it is reported the preparation of a food packaging based on isotactic polypropylene (PP) coated with layered double hydroxide (LDH) hosting sorbate as active molecule. The active nano-hybrid (LDH-sorbate) was dispersed into a food grade resin and used as coating. The release of the sorbate anchored to the LDH was compared to the release of the molecule free dispersed into the food grade resin and resulted much slower. It was evaluated the efficiency of the active packaging to inhibit Salmonella enterica subsp. arizonae, Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, Campylobacter jejuni, and the global migration using two food simulant (i.e. poly (2,6-diphenyl-p-phenylene oxide) and vegetable oil). Experimental data, in compliance with the migration limits of the European Union regulation, demonstrated the suitability of the prepared material for food contact. White bread was packed into the active PP film and untreated PP, as control. Organoleptic characteristics, moisture analysis, peroxide evolution and mold count showed that the bread packaged in the active film retained its starting characteristics up to 12 days of storage at ambient temperature.

Resin-based composites are widely used as dental restorative materials due to their excellent properties. They must have high modulus, high hardness, and be chemically inert while minimizing moisture uptake. To fulfill these higher standard prerequisites and properties, continuous improvements in each of their components are required. This study develops novel composites with multiple biofunctions. Light-cured Bis-GMA/TEGDMA dental resin (RK)/layered double hydroxide intercalated with fluoride ions (LDH-F)/calcium bentonite (Bt) hybrid composites were prepared. The loading ratio of LDH-F to Bt was varied, ranging from 2.5/2.5 to 10/10 parts per hundred RK and structural, mechanical, and biological properties were studied. The incorporation of even small mass fractions (e.g., 2.5 wt % of LDH-F and 2.5 wt % of Bt) in RK dental resin significantly improved the mechanical properties of the pristine resin. The synthetized materials showed antibacterial and antibiofilm effects against three bacterial strains isolated from healthy volunteers&rsquo, saliva (Streptococcus spp., Bacteroides fragilis, and Staphylococcus epidermidis) without affecting its ability to induce dental pulp stem cells differentiation into odontoblast-like cells. The capability to balance between the antibiofilm activity and dental pulp stem cells differentiation in addition with improved mechanical properties make these materials a promising strategy in preventive and restorative dentistry.

Layered double hydroxide (LDH) nanofillers were considered as hosts of p-hydroxybenzoate as an antimicrobial molecule for active coating. A food grade resin with LDH-p-hydroxybenzoate and two different types of food grade zeolites was used to prepare active coatings for Polyethylene terephthalate (PET) trays. The release kinetics of the active molecule were followed using UV spectrophotometry and the experimental results were analyzed with the Gallagher&ndash, Corrigan model. The thermal properties of the coating mixtures and the PET coating were analyzed and found to be dependent on the coating&rsquo, s composition. On the basis of CO2 transmission rate and off-odors tests, the best coating composition was selected. Global migration in ethanol (10% v/v), acetic acid (3% w/v), and vegetable oil, and specific migration of p-hydroxybenzoic acid revealed the suitability of the material for food contact. Antimicrobial tests on the packaging demonstrated a good inhibition against Salmonella spp. and Campylobacter jejuni. Red meat was packed into the selected active materials and results were compared to uncoated PET packaging. Color tests (browning of the meat) and analysis of Enterobacteriaceae spp. and total viable count evolution up to 10 days of storage demonstrated the capability of the considered active packaging in prolonging the shelf life of red meat.

Fluoride-releasing restorative dental materials can be beneficial to remineralize dentin and help prevent secondary caries. However, the effects of fluoride release from dental materials on the activity of dental pulp stem cells are not known. Here we investigate whether different fluoride release kinetics from dental resins supplemented with modified hydrotalcite (RK-F10) or fluoride-glass filler (RK-FG10) could influence the behavior of a human dental pulp stem cell subpopulation (STRO-1+ cells) known for its ability to differentiate toward an odontoblast-like phenotype. The 2 resins, characterized by similar physicochemical properties and fluoride content, exhibited different long-term fluoride release kinetics. Our data demonstrate that long-term exposure of STRO-1+ cells to a continuous release of a low amount of fluoride by RK-F10 increases their migratory response to transforming growth factor β1 (TGF-β1) and stromal cell–derived factor 1 (SDF-1), both important promoters of pulp stem cell recruitment. Moreover, the expression patterns of dentin sialoprotein ( dspp), dentin matrix protein 1 ( dmp1), osteocalcin ( ocn), and matrix extracellular phosphoglycoprotein ( mepe) indicate a complete odontoblast-like cell differentiation only when STRO-1+ cells were cultured on RK-F10. On the contrary, RK-FG10, characterized by an initial fluoride release burst and reduced lifetime of the delivery, did not elicit any significant effect on both STRO-1+ cell migration and differentiation. Taken together, our results highlight the importance of taking into account fluoride release kinetics in addition to fluoride concentration when designing new fluoride-restorative materials.