Development and characterization of novel packaging films from composite mixtures of rice-starch, tara gum and pectin.

Biodegradable films intend to replace polymers derived from petroleum. The effect of pectin and Tara gum on the properties of films prepared with rice starch and glycerol was studied in this context. FTIR analysis determined the presence of complex interactions between the components. SEM showed regular film surface with minor roughness. The evaluation of mechanical properties of the films proved the importance of pectin, Tara gum and glycerol concentration. When the proportion of pectin to Tara gum was 1:1, the tension at break, the elongation and the solubility reached the highest values while the water vapor permeability dropped to a minimum. Statistical analysis demonstrated non-linear behavior between composition and properties of the films and stated the importance of interactions between the components. Films produced from rice starch and glycerol in combination with pectin and Tara gum present competitive properties in terms of elongation, tensile stress, permeability to water vapor and solubility, displaying a uniform structure suitable for the packaging of food materials.

Li-doped bioglass® 45S5 for potential treatment of prevalent oral diseases.

OBJECTIVES: Despite the excellent properties of both pure bioglasses (BG) and BG doped with therapeutic ions (such as Li) in hard tissue applications, there is not enough information about their role in the remineralization and bacterial-growth in oral diseases. The aim of this contribution is to evaluate the effect of both pure BG and BG doped with 5-wt% of Li (BGLi) on both the remineralization of in vitro demineralized human-teeth and the antimicrobial behavior against strains from caries and periodontitis. METHODS: Bioglass® 45S5 (BG) and BGLi were synthesized by the sol-gel method. The remineralization tests were carried out using in vitro demineralized enamel teeth and evaluated by Electron Microscopy (SEM) and Vickers micro-hardness (HV). The antimicrobial behavior of the particles was evaluated against S. mutans, A. actinomycetemcomitans, and P. gingivalis, representing pathogens from caries and periodontitis. RESULTS: Enamel lesion was partially remineralized when both bioglasses (BG and BGLi) were applied on its surface with micro-hardness recoveries around 45 %. They further inhibited the growth of S. mutans and P. gingivalis, at 50 and 200 mg/mL, respectively. BGLi presented a higher toxicity against A. actinomycetemcomitans than BG, with inhibition concentrations of 20 mg/mL and 100 mg/mL, respectively. CONCLUSIONS: Bioglasses could be used in the treatment of two of the most prevalent oral diseases: caries and periodontitis, promoting the remineralization of the teeth and killing the main pathogens. The presence of Li did not affect the bioactivity of the bioglass and improved the antibacterial effect over A. actinomycetemcomitans strain.