The main objectives of this study were to develop and characterize hydrophilic polymeric membranes impregnated with poly-lactic acid (PLA) nanoparticles (NPs) combined with red propolis (RP). Ultrasonic-assisted extraction was used to obtain 30% (w/v) red propolis hydroalcoholic extract (RPE). The NPs (75,000 g mol⁻¹) alone and incorporated with RP (NPRP) were obtained using the solvent emulsification and diffusion technique. Biopolymeric hydrogel membranes (MNPRP) were obtained using carboxymethylcellulose (CMC) and NPRP. Their characterization was performed using thermal analysis, Fourier transform infrared (FTIR), total phenols (TPC) and flavonoids contents (TFC), and antioxidant activity through the radical scavenging assay with 2,2-diphenyl-1-picrylhydrazyl radical (DPPH) and Ferric reducing antioxidant power (FRAP). The identification and quantification of significant RP markers were performed through UPLC-DAD. The NPs were evaluated for particle size, polydispersity index, and zeta potential. The TPC for RPE, NPRP, and MNPRP was 240.3 ± 3.4, 191.7 ± 0.3, and 183.4 ± 2.1 mg EGA g⁻¹, while for TFC, the value was 37.8 ± 0.9, 35 ± 3.9, and 26.8 ± 1.9 mg EQ g⁻¹, respectively. Relevant antioxidant activity was also observed by FRAP, with 1400.2 (RPE), 1294.2 (NPRP), and 696.2 µmol Fe2+ g⁻¹ (MNPRP). The primary markers of RP were liquiritigenin, isoliquiritigenin, and formononetin. The particle sizes were 194.1 (NPs) and 361.2 nm (NPRP), with an encapsulation efficiency of 85.4%. Thermal analysis revealed high thermal stability for the PLA, nanoparticles, and membranes. The DSC revealed no interaction between the components. FTIR allowed for characterizing the RPE encapsulation in NPRP and CMC for the MNPRP. The membrane loaded with NPRP, fully characterized, has antioxidant capacity and may have application in the treatment of skin wounds.

Alginate encapsulates loaded with clove essential oil (CEO) were prepared by ionic gelation, with subsequent freeze-drying. The objective of the present work was to develop a product with the ability to protect CEO against its easy volatility and oxidation. The following techniques were used to characterize the formulations: eugenol release, degree of swelling, GC/MS, TGA/DSC, and SEM. The alginate solution (1.0%) containing different concentrations of CEO (LF1: 1.0%; LF2: 0.5%; LF3: 0.1%) was dropped into a 3.0% CaCl₂ solution. After lyophilization, the encapsulated samples were wrinkled and rigid, with high encapsulation power (LF3: 76.9% ± 0.5). Three chemical components were identified: eugenol (the major one), caryophyllene, and humulene. The antioxidant power (LF1: DPPH IC₅₀ 18.1 µg mL⁻¹) was consistent with the phenol content (LF1: 172.2 mg GAE g⁻¹). The encapsulated ones were thermally stable, as shown by analysis of FTIR peaks, eugenol molecular structure was kept unaltered. The degree of swelling was 19.2% (PBS). The release of eugenol (92.5%) in the PBS solution was faster than in the acidic medium. It was concluded that the low-cost technology used allows the maintenance of the content and characteristics of CEO in the three concentrations tested, offering a basis for further research with essential oil encapsulates.

Publique sua obra como capitulo de livro no SCISAÚDE. DOI. Ficha Catalográfica. ISBN. Fique por dentro de nosso congressos @scisaude

The objective of this work was to develop a product capable of protecting Syzygium aromaticum (clove) essential oil against high volatility. Clove oil (CEO) was encapsulated in alginate by ionic gelation with subsequent freeze-drying. Characterization was carried out by GC/MS, TGA/DSC and antioxidant (DPPH), and total phenol (Folin-Ciocalteau) analysis. Eugenol was the majority (81.5%) and the encapsulation efficiency varied between 14.0%+0.96 (F1: 1.0% alginate) and 9.8%+0.35 (F2: 2.0% alginate) in wet encapsulates, and 23.5%+0.14 (LF1: 1.0% alginate) and 16.9%+0.16 (LF2: 2.0% alginate) in freeze-dried encapsulates. The total phenol content reached 714.8+0.97 EAG g-1 in LF1, with strong inhibition of the DPPH radical (71.4%). Freeze-drying provided a higher percentage of active ingredients per gram of encapsulated and it was possible to identify high thermal stability in LF1 (mass loss: 81.8%; 258.9 °C) compared to wet encapsulates (mass loss: 86.5%; 65.8°C). The use of the lowest concentration of alginate seems to have been favorable. In this way, the accessible technology used allows preserving the content and properties of the CEO, offering a basis for new encapsulated research.