Amphotericin B-loaded natural latex dressing for treating Candida albicans wound infections using Galleria mellonella model.

Amphotericin B (AmB) is the gold standard for antifungal drugs. However, AmB systemic administration is restricted because of its side effects. Here, we report AmB loaded in natural rubber latex (NRL), a sustained delivery system with low toxicity, which stimulates angiogenesis, cell adhesion and accelerates wound healing. Physicochemical characterizations showed that AmB did not bind chemically to the polymeric matrix. Electronic and topographical images showed small crystalline aggregates from AmB crystals on the polymer surface. About 56.6% of AmB was released by the NRL in 120 h. However, 33.6% of this antifungal was delivered in the first 24 h due to the presence of AmB on the polymer surface. The biomaterial's excellent hemo- and cytocompatibility with erythrocytes and human dermal fibroblasts (HDF) confirmed its safety for dermal wound application. Antifungal assay against Candida albicans showed that AmB-NRL presented a dose-dependent behavior with an inhibition halo of 30.0 ± 1.0 mm. Galleria mellonella was employed as an in vivo model for C. albicans infection. Survival rates of 60% were observed following the injection of AmB (0.5 mg.mL-1) in G. mellonella larvae infected by C. albicans. Likewise, AmB-NRL (0.5 mg.mL-1) presented survival rates of 40%, inferring antifungal activity against fungus. Thus, NRL adequately acts as an AmB-sustained release matrix, which is an exciting approach, since this antifungal is toxic at high concentrations. Our findings suggest that AmB-NRL is an efficient, safe, and reasonably priced ($0.15) dressing for the treatment of cutaneous fungal infections.

Eco-sustainable coatings based on chitosan, pectin, and lemon essential oil nanoemulsion and their effect on strawberry preservation.

Films and coatings manufactured with bio-based renewable materials, such as biopolymers and essential oils, could be a sustainable and eco-friendly alternative for protecting and preserving agricultural products. In this work, we developed films and coatings from pectin and chitosan to protect strawberries (Fragaria x ananassa Duch.) from spoilage and microbial contamination. We developed three coatings containing equal amounts of glycerol and Sicilian lemon essential oil (LEO) nanoemulsion. We identified seventeen chemicals from LEO by GC-MS chromatogram, including d-limonene, α-Pinene, ß-Pinene, and γ-Terpinene. The pectin and chitosan coatings were further characterized using different physicochemical, mechanical, and biological methods. The films demonstrated satisfactory results in strength and elongation at the perforation as fruit packaging. In addition, the coatings did not influence the weight and firmness of the strawberry pulps. We observed that 100 % essential oil was released in 1440 min resulting from the erosion process. Also, the oil preserved the chemical stability of the films. Antioxidant activity (AA), measured by Electron Paramagnetic Resonance (EPR), showed that the coatings loaded with 2 % LEO nanoemulsion (PC + oil) showed that almost 50 % of AA from LEO nanoemulsion was preserved. The chitosan and the pectin-chitosan coatings (PC + oil) inhibited filamentous fungi and yeast contaminations in strawberries for at least 14 days, showing a relationship between the AA and antimicrobial results.

Biocompatible anti-aging face mask prepared with curcumin and natural rubber with antioxidant properties.

Natural rubber latex (NRL) is a biopolymer widely used in biomedical applications. In this work, we propose an innovative cosmetic face mask, combining the NRL's biological properties with curcumin (CURC), which has a high level of antioxidant activity (AA) to provide anti-aging benefits. Chemical, mechanical and morphological characterizations were performed. The CURC released by the NRL was evaluated by permeation in Franz cells. Cytotoxicity and hemolytic activity assays were performed to assess safety. The findings showed that the biological properties of CURC were preserved after loading in the NRL. About 44.2 % of CURC was released within the first six hours, and in vitro permeation showed that 9.36 % ± 0.65 was permeated over 24h. CURC-NRL was associated with a metabolic activity higher than 70 % in 3 T3 fibroblasts, cell viability ≥95 % in human dermal fibroblasts, and a hemolytic rate ≤ 2.24 % after 24 h. Furthermore, CURC-NRL maintained the mechanical characteristics (range suitable) for human skin application. We observed that CURC-NRL preserved ~20 % antioxidant activity from curcumin-free after loading in the NRL. Our results suggest that CURC-NRL has the potential to be used in the cosmetics industry, and the experimental methodology utilized in this study can be applied to different kinds of face masks.