Antimicrobial Wound Dressings based on Bacterial Cellulose and Independently Loaded with Nutmeg and Fir Needle Essential Oils

Bacteria-Derived Cellulose Membranes Modified with Graphene Oxide-Silver Nanoparticles for Accelerating Wound Healing

This study reports on the modification of bacterial cellulose (BC) membranes produced by static fermentation of Komagataeibacter xylinus bacterial strains with graphene oxide-silver nanoparticles (GO-Ag) to yield skin wound dressings with improved antibacterial properties. The GO-Ag sheets were synthesized through chemical reduction with sodium citrate and were utilized to functionalize the BC membranes (BC/GO-Ag). The BC/GO-Ag composites were characterized to determine their surface charge, morphology, exudate absorption, antimicrobial activity, and cytotoxicity by using fibroblast cells. The antimicrobial activity of the wound dressings was assessed against Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa. The results indicate that the BC/GO-Ag dressings can inhibit ∼70% of E. coli cells. Our findings also revealed that the porous BC/GO-Ag antimicrobial dressings can efficiently retain 94% of exudate absorption after exposure to simulated body fluid (SBF) for 24 h. These results suggest that the dressings could absorb excess exudate from the wound during clinical application, maintaining adequate moisture, and promoting the proliferation of epithelial cells. The BC/GO-Ag hybrid materials exhibited excellent mechanical flexibility and low cytotoxicity to fibroblast cells, making excellent wound dressings able to control bacterial infectious processes and promote the fast healing of dermal lesions.

Development of silanized bacterial cellulose aerogels for the incorporation of natural oils with healing properties: Copaiba (Copaifera officinalis), bourbon geranium (Pelargonium X ssp.) essential oils and buriti (Mauritia flexuosa) vegetable oil

Bacterial cellulose (BC) represents a promising biomaterial, due to its unique and versatile properties. We report, herein, on purposely-designed structural modifications of BC that enhance its application as a wound dressing material. Chemical modification of the functional groups of BC was performed initially to introduce a hydrophobic/oleophilic character to its surface. Specifically, silanization was carried out in an aqueous medium using methyltrimethoxisilane (MTMS) as the silanizing agent, and aerogels were subsequently prepared by freeze-drying. The BC-MTMS aerogel obtained displayed a highly porous (99 %) and lightweight structure with an oil absorption capacity of up to 52 times its dry weight. The XRD pattern indicated that the characteristic crystallographic planes of the native BC were maintained after the silanization process. Thermal analysis showed that the thermal stability of the BC-MTMS aerogel increased, as compared to the pure BC aerogel (pBC). Moreover, the BC-MTMS aerogel was not cytotoxic to fibroblasts and keratinocytes. In the second step of the study, the incorporation of natural oils into the aerogel's matrix was found to endow antimicrobial and/or healing properties to BC-MTMS. Bourbon geranium (Pelargonium X ssp.) essential oil (GEO) was the only oil that exhibited antimicrobial activity against the tested microorganisms, whereas buriti (Mauritia flexuosa) vegetable oil (BVO) was non-cytotoxic to the cells. This study demonstrates that the characteristics of the BC structure can be modified, while preserving its intrinsic features, offering new possibilities for the development of BC-derived materials for specific applications in the biomedical field.

Wound healing effect of nutmeg (Myristica fragrans) cream on second-degree burn in animal model

Second-degree burn, the most common among burn degrees, underscores the importance of timely and proper treatment in influencing prognosis. Nutmeg (Myristica fragrans), renowned for its potent antibacterial and antifungal properties, also serves as an effective antiseptic for open wounds. The aim of this study was to identify the phytochemical constituents of nutmeg essential oil and analyze the wound healing effect of nutmeg cream on second-degree burns in an animal model. An experimental study with a completed randomized design was conducted on Rattus norvegicus strain Wistar rats with second-degree burn. This study had four groups and each group consisting of four rats: B (burn-treated base cream), B+N (burn-treated 3% nutmeg cream), B+SSD (burn-treated silver sulfadiazine (BSS)), and B+N+SSD (burn-treated 3% nutmeg cream and SSD in a 1:1 ratio). The phytochemical analysis of nutmeg essential oil was conducted by gas chromatography and mass spectroscopy (GC-MS). The burn diameter and burn wound healing percentage were measured from day 0 to 18. One-way ANOVA followed by post hoc analysis using the least significant difference (LSD) was employed to analysis the effect. The phytochemical analysis of nutmeg essential oil found that myristicin, terpinene-4-ol, terpinene, safrole and terpinolene were the most abundant putative compounds in nutmeg essential oil. On day 0, the average burn wound diameters were 1.4 cm in all groups and increases were observed in all groups on day 3. The wound diameter decreased until day 18 with the smallest burn wound diameter was found in the B+N group (0.86±0.37 cm), followed by B+SSD (0.93±0.29 cm). The B+SSD group exhibited the highest percentage of burn wound healing (56.80±14.05%), which was significantly different from the base cream (p<0.05). The percentage of burn wound healing in rats given 3% nutmeg cream was 41.88±13.81%, suggesting that nutmeg cream could promote burn wound healing in rats induced by second-degree burns.

Unlocking sustainable solutions: Nanocellulose innovations for enhancing the shelf life of fruits and vegetables - A comprehensive review

Regarding food security and waste reduction, preserving fruits and vegetables is a vital problem. This comprehensive study examines the innovative potential of coatings and packaging made of nanocellulose to extend the shelf life of perishable foods. The distinctive merits of nanocellulose, which is prepared from renewable sources, include exceptional gas barrier performance, moisture retention, and antibacterial activity. As a result of these merits, it is a good option for reducing food spoilage factors such as oxidation, desiccation, and microbiological contamination. Nanocellulose not only enhances food preservation but also complies with industry-wide environmental objectives. This review explores the many facets of nanocellulose technology, from its essential characteristics to its use in the preservation of fruits and vegetables. Furthermore, it deals with vital issues including scalability, cost-effectiveness, and regulatory constraints. While the use of nanocellulose in food preservation offers fascinating potential, it also wants to be cautiously careful to assure affordability, effectiveness, and safety. To fully use the potential of nanocellulose and advance the sustainability plan in the food business, collaboration between scientists, regulatory bodies, and industry stakeholders is important as we stand on the cusp of a revolutionary era in food preservation.