Essential oils are products obtained from a natural raw material of plant origin, by steam distillation, mechanical processes of citrus fruit epicarp, or dry distillation after separation of the aqueous phase by physical processes. They are usually composed by secondary metabolites of aromatic plants with oxygenated structures such as alcohols, ketones, aldehydes, and esters, presenting therapeutic properties such as antibacterial, antifungal and antioxidant activities.Essential oils represent a small fraction of plant composition, but confer the characteristics for which aromatic plants are used in the pharmaceutical, food, and fragrance industries.The increasing use of plants by the pharmaceutical industry makes the study of essential oils crucial for the development of new bioactive delivery systems. This paper presents a literature review that summarizes the best advanced data regarding the use of essential oils and their volatile constituents for biomedical applications and focuses on innovative pharmaceutical formulations covering essential oils. Nonetheless it seems clear that more clinical evaluations are required until essential oils can be considered as possible applications in pharmacy or as adjuvants to current medications.

Due to its intrinsic similarity to the extracellular matrix, gelatin electrospun nanofibrous meshes are promising scaffold structures for wound dressings and tissue engineering applications. However, gelatin is water soluble and presents poor mechanical properties, which generally constitute relevant limitations to its applicability. In this work, gelatin was in situ crosslinked with 1,4-butanediol diglycidyl ether (BDDGE) at different concentrations (2, 4 and 6 wt-%) and incubation time-points (24, 48 and 72h) at 37ºC. The physico-chemical and biological properties of BDDGEcrosslinked electrospun gelatin meshes were investigated. Results show that by changing the BDDGE concentration it is possible to produce nanofibers crosslinked in situ with well-defined morphology and modulate fiber size and mechanical properties. Crosslinked gelatin meshes show no toxicity towards fibroblasts, stimulating their adhesion, proliferation and synthesis of new extracellular matrix, thereby indicating the potential of this strategy for skin tissue engineering.

In situ cross-linked hydrogels have the advantage of effectively fulfilling the wound in its shape and depth. Amongst the new generation of natural-based biopolymers being proposed for wound care and skin regeneration, silk sericin is particularly interesting due to its exceptional properties such as biocompatibility, biodegradability, and antioxidant behavior, among others. In this study, a new enzyme-mediated cross-linked hydrogel composed of silk sericin is proposed for the first time. The developed hydrogel cross-linking strategy was performed via horseradish peroxidase, under physiological conditions, and presented gelling kinetics under 3 min, as demonstrated by its rheological behavior. The hydrogels presented a high degree of transparency, mainly due to their amorphous conformation. Degradation studies revealed that the hydrogels were stable in phosphate buffer solution (PBS) (pH 7.4) for 17 days, while in the presence of protease XIV (3.5 U/mg) and under acute and chronic physiological pH values, the stability decreased to 7 and 4 days, respectively. During protease degradation, the present sericin hydrogels demonstrated antioxidant activity. In vitro studies using an L929 fibroblast cell line demonstrated that these hydrogels were noncytotoxic, promoting cell adhesion and massive cell colonization after 7 days of culture, demonstrating that cells maintained their viability and proliferation. In addition, the application of sericin-based hydrogel in an in vivo diabetic wound model validated the feasibility of the in situ methodology and demonstrated a local anti-inflammatory effect, promoting the healing process. This study presents a simple, fast, and practical in situ approach to produce a sericin-based hydrogel able to be applied in low exudative chronic wounds. Moreover, the study herein reported fosters the valorization of a textile industrial by-product by its integration in the biomedical field.

In chronic wounds, the regeneration process is compromised, which brings complexity to the therapeutic approaches that need to be adopted, while representing an enormous loss in the patients’ quality of life with consequent economical costs. Chronic wounds are highly prone to infection, which can ultimately lead to septicemia and morbidity. Classic therapies are increasing antibiotic resistance, which is becoming a critical problem beyond complex wounds. Therefore, it is essential to study new antimicrobial polymeric systems and compounds that can be effective alternatives to reduce infection, even at lower concentrations. The biological potential of polyphenols allows them to be an efficient alternative to commercial antibiotics, responding to the need to find new options for chronic wound care. Nonetheless, phenolic compounds may have some drawbacks when targeting wound applications, such as low stability and consequent decreased biological performance at the wound site. To overcome these limitations, polymeric-based systems have been developed as carriers of polyphenols for wound healing, improving its stability, controlling the release kinetics, and therefore increasing the performance and effectiveness. This review aims to highlight possible smart and bio-based wound dressings, providing an overview of the biological potential of polyphenolic agents as natural antimicrobial agents and strategies to stabilize and deliver them in the treatment of complex wounds. Polymer-based particulate systems are highlighted here due to their impact as carriers to increase polyphenols bioavailability at the wound site in different types of formulations.

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Chronic wounds are one of the most frequent complications that are associated with diabetes mellitus. The overproduction of reactive oxygen species (ROS) is a key factor in the delayed healing of a chronic wound. In the present work, we develop a novel in situ-forming silk sericin-based hydrogel (SSH) that is produced by a simple methodology using horseradish peroxidase (HRP) crosslinking as an advanced dressing for wound healing. The antioxidant and angiogenic effects were assessed in vitro and in vivo after in situ application using an excisional wound-healing model in a genetically-induced diabetic db/db mice and though the chick embryo choriollantoic membrane (CAM) assay, respectively. Wounds in diabetic db/db mice that were treated with SSH closed with reduced granulation tissue, decreased wound edge distance, and wound thickness, when compared to Tegaderm, a dressing that is commonly used in the clinic. The hydrogel also promoted a deposition of collagen fibers with smaller diameter which may have had a boost effect in re-epithelialization. SSH treatment slightly induced two important endogenous antioxidant defenses, superoxide dismutase and catalase. A CAM assay made it possible to observe that SSH led to an increase in the number of newly formed vessels without inducing an inflammatory reaction. The present hydrogel may result in a multi-purpose technology with angiogenic, antioxidant, and anti-inflammatory properties, while advancing efficient and organized tissue regeneration.

The largest human organ, the skin, serves a variety of essential functions including protection, preservation of water and electrolytes, regulation of body temperature, and fat storage. Its maintenance and preservation are supported by cosmetic products, whose functions include cleaning, protection, and modulation. The market for these products is predicted to increase from 100.13 billion USD in 2021 to 145.82 billion USD in 2028. Recently, it has been suggested that grape by-products (totalling 14.5 million tons per year just in Europe) has a great potential to be used in the creation of new cosmetic products. In this regard, this article aims to provide a comprehensive overview of the current state of knowledge regarding the bioactive compounds in grape pomace, the advantages of applying them to the skin, and the main cosmetic products already on the market incorporating these bioactives. Most of these compounds are derived from the Vitis vinifera L. species, and exhibit several biological properties, such as antioxidant, antimicrobial, anti-inflammatory, inhibition of skin degrading enzymes, protection from UVA damage, increased cell viability, and skin whitening effect. On the other hand, nanoencapsulation techniques can provide a significant improvement in the stability of grape-derived bioactive compounds, in particular of resveratrol, and this issue is also addressed in a critical manner in this review.