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Highlights-PLA nanoparticles loaded with Thymol were prepared for the first time.-The PLA was found to be the key variable in optimizing the nanoparticle preparation.-The nanoparticles exhibited a high storage stability over a wide range of pHs.-The antimicrobial activity of the nanoparticles was tested on apple pieces.

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Vanillin is a natural compound easily extracted from plants. It has neuroprotective, anti-carcinogenic, antioxidant, antimicrobial, and anti-biofilm properties. It also presents high volatility, high hydrophilicity, and low bioavailability. Nanomaterials can be used to improve pharmacodynamics, solubility, and stability and to enhance pharmacokinetics. In this work, non-ionic surfactant vesicles were synthesized as vanillin carriers: neutral niosomes formed by Span60 and cholesterol, positive charged niosomes formulated with cetyltrimethylammonium bromide (CTAB), and negatively charged niosomes formulated with sodium dodecyl sulfate (SDS). Niosomes synthesis was carried out with two commonly used methods: thin film hydration (TFH) and ethanol injection method (EIM). The niosomes synthesized were used to prepare two different materials: (i) a powder containing the lyophilized noisome with vanillin systems and (ii) a gelatin matrix film containing niosomes with vanillin. Lyophilization was carried out using maltodextrin as a cryoprotectant. The lyophilization of colloidal structures allows for storage at room temperature for long periods of time, keeping their organoleptic characteristics invariable. Niosomes were characterized before and after the lyophilization process in terms of morphological characterization, size, polydispersity index (PDI), and zeta potential. Moreover, niosomes cargo was evaluated by calculating the encapsulation efficiency (EE) and loading capacity (LC). Results showed that the use of the TFH method allowed us to obtain niosomes of 255 nm with high EE (up to 40%) and LC values higher than EIM. The lyophilization process decreased the LC of the vesicles prepared, but this decrease was mitigated by up to 20% when ionic surfactants were used on the membrane bilayer. Gelatin films are biodegradable materials suitable for food packing applications. The incorporation of a natural compound with antimicrobial activity would be a clear advantage for such an application. The films prepared were characterized in terms of morphology, water solubility, color, and transparency. Niosomes synthesized by thin film hydration had better chemical and physical properties to load vanillin. Especially in the case of application in films, niosomes with a negative charge, formed by SDS, and vanillin loaded gave better mechanical and chemical characteristics to the film.

After the incorporation of the polyaniline (PANI), polymethyl methacrylate (PMMA) composites with outstanding electrical conductivity had been widely used in sensors. However, the flame retardancy of PMMA composites seriously restrained its further application. Thus, phosphorus‐containing polyaniline (FR‐PANI) was successfully prepared and combined with PMMA. The flame retardancy, electrical conductivity, thermal stability, and fire behavior of the resultant PMMA/FR‐PANI composites were systematically studied. When the loading amount of FR‐PANI was controlled at 20 wt%, the PMMA matrix was endowed with dramatic flame retardancy, exhibiting a limiting oxygen index of 29.1% and a UL‐94 V‐0 rating in vertical burning tests. Meanwhile, the volume resistivity was also reduced up to 0.5 MΩ. The thermal stability of the PMMA/FR‐PANI composites was enhanced by the formation of abundant char residue, which improved the fire behavior of the PMMA matrix. The effect of FR‐PANI on the flame retardancy of the PMMA matrix was deduced on the basis of thermogravimetry‐infrared, Fourier transform infrared, and scanning electron microscopic analyses. The phosphorus‐containing functional groups in the FR‐PANI molecular chain underwent thermal degradation in the condensed phase and promoted the formation of a char layer. The char layer, in turn, prevented heat transfer into the interior of the PMMA composites, serving as a barrier to the volatilization of flammable micromolecules. Therefore, FR‐PANI is an important candidate to extend the range of applications of PMMA to include multifunctional intelligent sensors.

Proteins, such as those in blood from slaughterhouses, are a good option for developing edible films. However, films made exclusively from proteins have low strength and high water solubility, which makes them difficult to use in the food industry. The use of cellulosic material, such as nanofibrillated cellulose (NFC), can improve the properties of these films. In the present work, bovine plasma was acidified and treated with ethanol to precipitate its proteins, and these proteins were used to prepare films reinforced with several concentrations of NFC. In addition, control films prepared with untreated bovine plasma and reinforced with NFC were prepared as well. These new edible films were characterized according to their mechanical properties, water vapor permeability, light transmittance, and microstructure. Furthermore, the film with the best properties was selected to be additivated with nisin to test its antimicrobial properties by wrapping meat previously contaminated with Staphylococcus aureus. In this sense, films prepared with the extracted proteins showed better properties than the films prepared with untreated plasma. In addition, the results showed that the reinforcement of the films with a 10% (w/w) of NFC decreased their water solubility and improved their puncture strength and water vapor barrier properties. Finally, the addition of nisin to the films prepared with extracted protein from bovine plasma and NFC gave them antimicrobial properties against S. aureus.