In this work is presented a new category of self-growing, fibrous, natural composite materials with controlled physical properties that can be produced in large quantities and over wide areas, based on mycelium, the main body of fungi. Mycelia from two types of edible, medicinal fungi, Ganoderma lucidum and Pleurotus ostreatus, have been carefully cultivated, being fed by two bio-substrates: cellulose and cellulose/potato-dextrose, the second being easier to digest by mycelium due to presence of simple sugars in its composition. After specific growing times the mycelia have been processed in order to cease their growth. Depending on their feeding substrate, the final fibrous structures showed different relative concentrations in polysaccharides, lipids, proteins and chitin. Such differences are reflected as alterations in morphology and mechanical properties. The materials grown on cellulose contained more chitin and showed higher Young’s modulus and lower elongation than those grown on dextrose-containing substrates, indicating that the mycelium materials get stiffer when their feeding substrate is harder to digest. All the developed fibrous materials were hydrophobic with water contact angles higher than 120°. The possibility of tailoring mycelium materials’ properties by properly choosing their nutrient substrates paves the way for their use in various scale applications.

Graphene is the first 2D crystal ever isolated by mankind. It consists of a single graphite layer, and its exceptional properties are revolutionizing material science. However, there is still a lack of convenient mass-production methods to obtain defect-free monolayer graphene. In contrast, graphene nanoplatelets, hybrids between graphene and graphite, are already industrially available. Such nanomaterials are attractive, considering their planar structure, light weight, high aspect ratio, electrical conductivity, low cost, and mechanical toughness. These diverse features enable applications ranging from energy harvesting and electronic skin to reinforced plastic materials. This review presents progress in composite materials with graphene nanoplatelets applied, among others, in the field of flexible electronics and motion and structural sensing. Particular emphasis is given to applications such as antennas, flexible electrodes for energy devices, and strain sensors. A separate discussion is included on advanced biodegradable materials reinforced with graphene nanoplatelets. A discussion of the necessary steps for the further spread of graphene nanoplatelets is provided for each revised field.

Bio-based and biodegradable packaging combined with chemical sensors and indicators has attracted great attention as they can provide protection combined with information on the actual freshness of foodstuffs. In this study, we present an effective, biodegradable, mostly bio-sourced material ideal for sustainable packaging that can also be used as a smart indicator of ammonia (NH₃) vapor and food spoilage. The developed material comprises a blend of poly(lactic acid) (PLA) and poly(propylene carbonate) (PPC) loaded with curcumin (CCM), which is fabricated via the scalable techniques of melt extrusion and compression molding. Due to the structural similarity of PLA and PPC, they exhibited good compatibility and formed hydrogen bonds within their blends, as proven by Fourier transform infrared (FTIR) and X-ray diffraction (XRD). Thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) analysis confirmed that the blends were thermally stable at the used processing temperature (180 °C) with minimal crystallinity. The rheological and mechanical properties of the PLA/PPC blends were easily tuned by changing the ratio of the biopolymers. Supplementing the PLA/PCC samples with CCM resulted in efficient absorption of UV radiation, yet the transparency of the films was preserved (T₇₀₀ ∼ 68–84%). The investigation of CCM extract in ethanol with the DPPH^• assay demonstrated that the samples could also provide effective antioxidant action, due to the tunable release of the CCM. Analyses for water vapor and oxygen permeability showed that the PPC improved the barrier properties of the PLA/PPC blends, while the presence of CCM did not hinder barrier performance. The capacity for real-time detection of NH₃ vapor was quantified using the CIELab color space analysis. A change in color of the sample from a yellowish shade to red was observed by the naked eye. Finally, a film of PLA/PPC/CCM was successfully applied as a sticker indicator to monitor the spoilage of shrimps over time, demonstrating an evident color change from yellow to light orange, particularly for the PPC-containing blend. The developed system, therefore, has the potential to serve as a cost-effective, easy-to-use, nondestructive, smart indicator for food packaging, as well as a means for NH₃ gas monitoring in industrial and environmental applications.

One of the current challenges in wound care is the development of multifunctional dressings that can both protect the wound from external agents and promote the regeneration of the new tissue. Here, we show the combined use of two naturally derived compounds, sodium alginate and lavender essential oil, for the production of bioactive nanofibrous dressings by electrospinning, and their efficacy for the treatment of skin burns induced by midrange ultraviolet radiation (UVB). We demonstrate that the engineered dressings reduce the risk of microbial infection of the burn, since they stop the growth of Staphylococcus aureus. Furthermore, they are able to control and reduce the inflammatory response that is induced in human foreskin fibroblasts by lipopolysaccharides, and in rodents by UVB exposure. In particular, we report a remarkable reduction of pro-inflammatory cytokines when fibroblasts or animals are treated with the alginate-based nanofibers. The down-regulation of cytokines production and the absence of erythema on the skin of the treated animals confirm that the here described dressings are promising as advanced biomedical devices for burn management.

Wound repair is a complex and tightly regulated physiological process, involving the activation of various cell types throughout each subsequent step (homeostasis, inflammation, proliferation, and tissue remodeling). Any impairment within the correct sequence of the healing events could lead to chronic wounds, with potential effects on the patience quality of life, and consequent fallouts on the wound care management. Nature itself can be of inspiration for the development of fully biodegradable materials, presenting enhanced bioactive potentialities, and sustainability. Naturally-derived biopolymers are nowadays considered smart materials. They provide a versatile and tunable platform to design the appropriate extracellular matrix able to support tissue regeneration, while contrasting the onset of adverse events. In the past decades, fabrication of bioactive materials based on natural polymers, either of protein derivation or polysaccharide-based, has been extensively exploited to tackle wound-healing related problematics. However, in today's World the exclusive use of such materials is becoming an urgent challenge, to meet the demand of environmentally sustainable technologies to support our future needs, including applications in the fields of healthcare and wound management. In the following, we will briefly introduce the main physico-chemical and biological properties of some protein-based biopolymers and some naturally-derived polysaccharides. Moreover, we will present some of the recent technological processing and green fabrication approaches of novel composite materials based on these biopolymers, with particular attention on their applications in the skin tissue repair field. Lastly, we will highlight promising future perspectives for the development of a new generation of environmentally-friendly, naturally-derived, smart wound dressings.