RESUMEN
The use of natural polymers, such as gelatin and other proteins, has increased in an attempt to replace part of the consumption of petroleum-based packaging. This study evaluated the influence of green tea extract and lemon nanoemulsion on mechanical, thermal and permeability properties of gelatin matrix. The results showed that green tea increased the gelatin tensile strength (TS) from 86 ± 7 MPa to 101 ± 5 MPa, on the other hand, the nanoemulsion decreases to 78 ± 8 MPa. The incorporation of green tea and nanoemulsion enhanced the water vapor permeability of gelatin film; this could be due to the interacting with the hydrophobic domains of gelatin. This was indicated by melting point (Tm) in differential scanning calorimetry (DSC) and degradation temperatures in the thermogravimetric analysis (TG), respectively. Changes in FTIR spectra of gelatin film were observed when the green tea and nanoemulsion were incorporated. Therefore, this study showed a new characterization and formulation of gelatin films incorporated by green tea extract and lemon nanoemulsion and their potential for edible film.
RESUMEN
The use of edible films has garnered significant interest in the food and environmental sectors due to their potential to prevent food deterioration and their biodegradability. This study aimed to develop and characterize edible films based on camu-camu residue, gelatin, and glycerol, evaluating their solubility, thermal, degradability, antioxidant, and water vapor permeability properties of the gelatin matrix. This is the first study incorporating camu-camu into a gelatin and glycerol matrix. The films produced with camu-camu residue were manageable and soluble, with some non-soluble residues, providing a shiny and well-presented appearance. In the biodegradation results, samples 3 and 4 appeared to degrade the most, being two of the three most affected samples in the triplicate. The films showed degradation modifications from the third day of the experiment. In the germination and plant growth analysis, sample 4 exhibited satisfactory development compared to the other samples, emerging as the sample with the best overall result in the analyses, attributed to a 13.84 cm increase in the growth of the upper part of the seedling. These results indicate that the produced materials have potential for food packaging applications.
RESUMEN
Hybrid nanocomposite hydrogels, as admixtures for internal curing of cementitious materials, have been widely studied. This study analyzes the effect of applying 0.5% (wt/wt cement) of pre-soaked hydrogels based on polyacrylamide, carboxymethylcellulose, and three different concentrations of Cloisite-Na+ (0, 10, and 20% wt/wt) on the fresh and hardened properties of cementitious mortars. In general, all mortars with hydrogel decreased the consistency index, mainly M20, due to the high concentration of Cloisite-Na+ that modifies the release kinect of the hydrogel. The results showed a slight variation, with an overall average value of 99% water retention in all mortars. This behavior is due to the portion of hydrogel-mortars dosage water retained to reduce the availability of free water in the mixture because this amount of water is stored, a priori, within the polymer particles. At 28 d, the mortars produced with hydrogels containing 20% of nanoclay (M20) exhibit mechanical behavior similar to the reference mortar (M), which corroborates the percentage of voids found. Scanning electron microscope images confirm that the M and M20 mortars are uniform and possess few pores or microcracks. Thus, these hybrid hydrogels have the potential to be innovative materials for water control improvements in cementitious materials technology.
RESUMEN
OBJECTIVES: The use of chitosan nanoparticles (CNPs) in endodontics is of interest due to their antibiofilm properties. This study was to investigate the ability of bioactive CNPs to remove the smear layer and inhibit bacterial recolonization on dentin. MATERIALS AND METHODS: One hundred bovine dentin sections were divided into five groups (n = 20 per group) according to the treatment. The irrigating solutions used were 2.5% sodium hypochlorite (NaOCl) for 20 min, 17% ethylenediaminetetraacetic acid (EDTA) for 3 min and 1.29 mg/mL CNPs for 3 min. The samples were irrigated with either distilled water (control), NaOCl, NaOCl-EDTA, NaOCl-EDTA-CNPs or NaOCl-CNPs. After the treatment, half of the samples (n = 50) were used to assess the chelating effect of the solutions using portable scanning electronic microscopy, while the other half (n = 50) were infected intra-orally to examine the post-treatment bacterial biofilm forming capacity. The biovolume and cellular viability of the biofilms were analysed under confocal laser scanning microscopy. The Kappa test was performed for examiner calibration, and the non-parametric Kruskal-Wallis and Dunn tests (p < 0.05) were used for comparisons among the groups. RESULTS: The smear layer was significantly reduced in all of the groups except the control and NaOCl groups (p < 0.05). The CNPs-treated samples were able to resist biofilm formation significantly better than other treatment groups (p < 0.05). CONCLUSIONS: CNPs could be used as a final irrigant during root canal treatment with the dual benefit of removing the smear layer and inhibiting bacterial recolonization on root dentin.