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Coral reefs are threatened by climate change and the effects of human activity on the marine environment. Researchers are attempting to rescue this fragile ecosystem through coral restoration actions, and a common step in these procedures is transplanting the new coral colonies into coral reefs. To do that, commercial concrete or epoxy resins, also called putty, are utilized, highlighting different concerns about their mechanical and hardening performances and their impact and fate once released into the environment. Hence, this study presents a new biodegradable epoxidized soybean oil acrylate (ESOA)/zein-based coral putty capable of quick hardening underwater as an ecofriendly alternative for transplantation of new coral colonies in the reef. Coral putty is composed of two components, containing one a radical initiator and the other a radical accelerator. Once the two components are mixed, coral putty becomes hard underwater in 20–25 min, showing a hardening timescale much faster than other commercial products. The coral putty is biocompatible when applied to the coral Stylophora pistillata in aquaria and Acropora tenuis corals are out-planted on the reef in the Maldives, demonstrating how this new class of vegetable-oil-based materials can be a more sustainable alternative to epoxy resins commonly used in coral restoration procedures.

The market of epoxy resin-based adhesives is constantly growing in the automotive, electronics, and healthcare industries thanks to their unique features such as high bonding strength, durability, and corrosion resistance. In this work, alternative sustainable vitrimer adhesives, containing from 20 to 50 wt% of lignin microparticles, were prepared from epoxidized linseed oil (ELO) and a boronic ester dithiol crosslinker (DBEDT), in the absence of solvents and catalysts. The addition of unmodified commercial Kraft lignin to the composites directly influences their thermal and mechanical properties and determines their bonding capacity between several adherent substrates, also affecting the rewelding potential. The lignin-vitrimer composites and the corresponding neat vitrimer matrix exhibited values of lap shear strengths in the range of 9 to 17 MPa, when tested as adhesives with aluminum, stainless steel, and wood specimens, and good to excellent rewelding capability. The amount of lignin microparticles influences the balance between cohesive and adhesive forces during the separation of the adhered aluminum surfaces and the eventual joint failure. In the case of the composites with 20 wt% of lignin, lap shear strength remains constant even after four cycles of rebonding via compression molding, indicating that the best rewelding performance is associated with previous cohesive failure when the adhesive remains on both aluminum sheets' surfaces. In addition, the adhesion was preserved for 83 % of the initial value after 24 h immersed in water. Importantly, biodegradability in both soil and seawater was enhanced by the presence of the lignin filler. In summary, the simple preparation strategy of bio-based vitrimer composites coming from two natural sources could pave the way to green alternatives for industrial applications, such as epoxy-based adhesives.

In this study, hydrogels were produced using a Schiff base reaction between two hyaluronic acid derivatives: one containing aldehyde groups (HA-Ald) and the other holding a diethylenetriamine with terminal amino groups (HA-DETA). The DETA portion promotes the in situ growth, complexation, and stabilization of silver nanoparticles (AgNPs), eliminating the need for external reducing agents. The reaction between HA-DETA and HA-Ald leads to the formation of imine bonds, which results in dynamically pH-responsive cross-linking. While the DETA capping ability helped in embedding the AgNPs, the on/off pH environmental responsivity of the hydrogel allows for a controlled and on-demand release of the drug, mainly when bacterial infections cause pH variation of the wound bed. The injectable hydrogels resulted in being highly compatible in contact with blood red cells, fibroblasts, and keratinocytes and capable of having a proliferative effect on an in vitro wound scratch model. The pH-responsive hydrogels showed proper antibacterial activity againstPseudomonas aeruginosaandStaphylococcus aureus, common bacterial strains presented in wound infections. Finally, in vivo wound model studies demonstrated an overall speeding up in the wound healing rate and advanced wound conditions in the experimental group treated with the hydrogels compared to control samples.

Diabetes is rising as one of the most diffused diseases of the century with the related urgent necessity to face its systemic and local effects on the patients, such as cardiovascular problems, degeneration of limbs, and dysfunction of the wound healing process. The diffusion of leg ulcers has been estimated to be 1.51 for 1000 population, and these non-resolved wounds can produce several social, economic, and mental health issues in diabetic patients. At the same time, these people experience neuropathic pain that causes morbidity and a further decrease in their quality of life. Here, a new study is presented where asodium alginate/Polyvinylpyrrolidone-Iodine complex (PVPI)-based wound dressing is combined with the Frequency Rhythmic Electrical Modulation System (FREMS) technology, an established medical device for the treatment of neuropathic pain and diabetic ulcers. The produced Alginate/PVPI-based films are characterized in terms of morphology, chemistry, wettability, bio-/hemo-compatibility, and clotting capacity. Next, the Alginate/PVPI-based films are used together with FREMS technology in diabetic mice models, and synergism of their action in the wound closure rate and anti-inflammatory properties is found. Hence, how the combination of electrical neurostimulation devices and advanced wound dressings can be a new approach to improve chronic wound treatment is demonstrated.

The predominant use of synthetic materials, such as fiberglass and polymeric foams, for thermal and acoustic insulation in the construction sector contributes to the recalcitrant waste accumulation in the environment and is not economically sustainable in the long term. This is because they are developed with linear economy standards, they are neither reusable nor recyclable, and, at their end of lifecycle, they are not compostable, with a great amount of them finishing in landfills. This work is focused on the development of natural, self-growing mycelium-biocomposites as sustainable alternatives to these conventional synthetic materials. Specifically, fungal mycelium derived from the nonpathogenic fungal strain Pleurotus ostreatus is fed by coffee silverskin flakes, a lignocellulosic agrowaste from roasted coffee seeds, forming 3D biocomposites. The physicochemical properties of the obtained composite are thoroughly investigated, with a final focus on their thermal and acoustic insulation properties. As proved, the natural agrowaste-mycelium composites possess high porosity and thus low density, good thermal properties, and satisfactory sound absorption capability. Such properties combined with the minimal energetic requirements for their growth and their fully compostable end-of-life nature make them valuable alternatives for thermal and acoustic insulation in building construction, among other applications, promoting environmental and economic sustainability.

Bacterial infections are a constant challenge in the management of acute and chronic wounds. Chronic wounds, such as diabetic foot ulcers, have increased significantly in the last few years due to the rise of an aging population. A better understanding of the infectious pathophysiological mechanisms is urgently needed along with new options for the treatment of wound infections and wound-healing disorders. New advances in the preparation of biocompatible dressing materials that can be loaded with antimicrobial drugs may improve the topical treatment of infected wounds. In this study, we investigated the antimicrobial activity of polyvinylpyrrolidone (PVP) foils loaded with ciprofloxacin (Cipro-foils) in the presence of acetic acid as a co-solvent. We used ex vivo human wounds that were infected with two bacterial strains: methicillin-resistant Staphylococcus aureus (MRSA) or Pseudomonas aeruginosa (PAO1). The effectiveness of the treatment was demonstrated by the quantification of the living bacteria extracted from the wound and the detection of released immunological mediators in skin extracts and in the skin culture media. We found that Cipro-foils effectively treated the infection with both PAO1 and MRSA. Other than PAO1, MRSA had no lytic activity toward skin proteins. MRSA infections increased cytokines’ expression and release. Interestingly, treatment with Cipro-foils could partially counteract these effects.

Introduction: Recently, mycelia of Ganoderma lucidum and Pleurotus ostreatus, edible fungi, have been characterized in vitro as self-growing biomaterials for tissue engineering since they are constituted of interconnected fibrous networks resembling the dermal collagen structure. Aim: This work aims to investigate the biopharmaceutical properties of G. lucidum and P. ostreatus mycelia to prove their safety and effectiveness in tissue engineering as dermal substitutes. Methods: The mycelial materials were characterized using a multidisciplinary approach, including physicochemical properties (morphology, thermal behavior, surface charge, and isoelectric point). Moreover, preclinical properties such as gene expression and in vitro wound healing assay have been evaluated using fibroblasts. Finally, these naturally-grown substrates were applied in vivo using a murine burn/excisional wound model. Conclusions: Both G. lucidum and P. ostreatus mycelia are biocompatible and able to safely and effectively enhance tissue repair in vivo in our preclinical model.

Here, the development of highly porous colorimetric indicators that are able to rapidly sense the presence of amine vapors is presented. Specifically, porous, curcumin-loaded polycaprolactone fibers are formed by electrospinning through non-solvent-induced phase separation. In comparison to the non-porous fibers, the developed system shows significantly higher sensitivity and responsivity to the presence of dimethylamine vapors, with a distinct color change at very low vapor concentrations (2.33 ppm compared to 9.26 ppm) within the first 5 s of exposure. Indeed, CIELAB analysis proves that the induced color changes can be easily perceived visually, as the differences between the initial and the final color of the indicator after its interaction with the modified environment are well above the limit for visual perception, even by inexperienced users. Furthermore, the color changes are reversible, enabling the use of the same indicator several times, making it, thus, a sustainable colorimetric indicator system that can be used in applications where the rapid detection of low concentration of alkaline vapors is necessary.

This review explores the colorimetric indicators based on anthocyanin polymer composites fabricated in the last decade, in order to provide a comprehensive overview of their morphological and compositional characteristics and their efficacy in their various application fields. Notably, the structural properties of the developed materials and the effect on their performance will be thoroughly and critically discussed in order to highlight their important role. Finally, yet importantly, the current challenges and the future perspectives of the use of anthocyanins as components of colorimetric indicator platforms will be highlighted, in order to stimulate the exploration of new anthocyanin sources and the in-depth investigation of all the possibilities that they can offer. This can pave the way for the development of high-end materials and the expansion of their use to new application fields.

Malva sylvestris (MS) is a medicinal herb known worldwide for its beneficial effects due to the several active molecules present in its leaves and flowers. These compounds have shown antioxidant and anti-inflammatory properties and thus can be helpful in treatments of burns and chronic wounds, characterized mainly by high levels of free radicals and impairments of the inflammatory response. In this work, we propose bilayer films as wound dressings, based on poly(vinylpyrrolidone) (PVP) and sodium alginate loaded with M. sylvestris extracts from leaves and flowers and fabricated by combining solvent-casting and rod-coating methods. The top layer is produced in two different PVP/alginate ratios and loaded with the MS flowers' extract, while the bottom layer is composed of PVP and MS leaves' extract. The bilayers were characterized morphologically, chemically, and mechanically, while they showed superior self-adhesive properties on human skin compared to a commercial skin patch. The materials showed antioxidant activity, release of the bioactive compounds, and water uptake property. Moreover, the anthocyanin content of the flower extract provided the films with the ability to change color when immersed in buffers of different pH levels. In vitro tests using primary keratinocytes demonstrated the biocompatibility of the MS bilayer materials and their capacity to enhance the proliferation of the cells in a wound scratch model. Finally, the best performing MS bilayer sample with a PVP/alginate ratio of 70:30 was evaluated in mice models, showing suitable resorption properties and the capacity to reduce the level of inflammatory mediators in UVB-induced burns when applied to an open wound. These outcomes suggest that the fabricated bilayer films loaded with M. sylvestris extracts are promising formulations as active and multifunctional dressings for treating skin disorders.

The invention describes a biocompatible and biodegradable composite material for the underwater delivery of active agent curcumin to reduce the effects of high seawater temperature on marine organisms such as corals. The antioxidant action of curcumin allows to mitigate the effect of climate change and improve the survival of ecosystems that are fragile, unique, biodiverse, and important for thousands of people worldwide like coral reefs.

Massive coral bleachingepisodes induced by thermal stress areone of the first causes of coral death worldwide. Overproduction ofreactive oxygen species (ROS) has been identified as one of the potentialcauses of symbiosis breakdown between polyps and algae in corals duringextreme heat wave events. Here, we propose a new strategy for mitigatingheat effects by delivering underwater an antioxidant to the corals.We fabricated zein/polyvinylpyrrolidone (PVP)-based biocomposite filmsladen with the strong and natural antioxidant curcumin as an advancedcoral bleaching remediation tool. Biocomposites' mechanical,water contact angle (WCA), swelling, and release properties can betuned thanks to different supramolecular rearrangements that occurby varying the zein/PVP weight ratio. Following immersion in seawater,the biocomposites became soft hydrogels that did not affect the coral'shealth in the short (24 h) and long periods (15 days). Laboratorybleaching experiments at 29 and 33 & DEG;C showed that coral coloniesof Stylophora pistillata coated withthe biocomposites had ameliorated conditions in terms of morphologicalaspects, chlorophyll content, and enzymatic activity compared to untreatedcolonies and did not bleach. Finally, biochemical oxygen demand (BOD)confirmed the full biodegradability of the biocomposites, showinga low potential environmental impact in the case of open-field application.These insights may pave the way for new frontiers in mitigating extremecoral bleaching events by combining natural antioxidants and biocomposites.

Coral reefs are among the most diverse ecosystems in the world. The diversity of life found in the habitats created by corals is so large that the reefs are known as the “rainforests of the sea.” Unfortunately, severe natural and anthropogenic changes such as ocean warming, acidification, coral diseases, and plastic pollution are extremely detrimental to this ecosystem. To enrich the ambient conditions of the corals and boost their growth, the potential of two biocomposites is evaluated based on biodegradable polyurethane and silicone matrices as scaffolds for the growth of oceanic organisms. Furthermore, their degradation is investigated within the coral reefs of Faafu Atoll, Republic of Maldives. The observations indicate that there are a significant number of organisms that settle and grow on these biocomposites in the Maldivian lagoon, both of an animal and photosynthetic nature. The biocomposites have the potential to become suitable scaffolds for diverse hard bottom fouling organisms. Moreover, the presence of coral larvae on the biocomposites suggests that during their biodegradation, these biocomposites can support the growth of organisms, generating a suitable environment for triggering the birth of new corals.

In response to the pervasive anthropogenic pollution of the ocean, this manuscript suggests the use of biodegradable elastomers in marine applications. The present study characterizes 25 samples of highly biodegradable polymers, obtained blending a base elastomer with natural fibers. Mechanical analysis and Scanning Electron Microscope imaging, reveal how base polymers behave differently depending on the plant fiber chosen, on the external forcing—exposure to water—and on the doses that constitute the final biocomposite. Results suggest that EcoflexTM 00-30 and EcoflexTM 00-50, mixed with potato starch, perform best mechanically, maintaining up to 70% of their maximum tensile strain. Moreover, early signs of degradation are visible on polysiloxane rubber blended with 50% vegetable fibers after 19 hours in distilled water. Analyses demonstrate that highly biodegradable elastomers are good candidates to satisfy the requirements of aquatic devices. Furthermore, the discussed materials can improve the dexterity and biodegradability of marine technology.

Alterations of skin homeostasis are widely diffused in our everyday life both due to accidental injuries, such as wounds and burns, and physiological conditions, such as late-stage diabetes, dermatitis, or psoriasis. These events are locally characterized by an intense inflammatory response, a high generation of harmful free radicals, or an impairment in the immune response regulation, which can profoundly change the skin tissue’ repair process, vulnerability, and functionality. Moreover, diabetes diffusion, antibiotic resistance, and abuse of aggressive soaps and disinfectants following the COVID-19 emergency could be causes for the future spreading of skin disorders. In the last years, hydroxycinnamic acids and derivatives have been investigated and applied in several research fields for their anti-oxidant, anti-inflammatory, and anti-bacterial activities. First, in this study, we give an overview of these natural molecules’ current source and applications. Afterwards, we review their potential role as valid alternatives to the current therapies, supporting the management and rebalancing of skin disorders and diseases at different levels. Also, we will introduce the recent advances in the design of biomaterials loaded with these phenolic compounds, specifically suitable for skin disorders treatments. Lastly, we will suggest future perspectives for introducing hydroxycinnamic acids and derivatives in treating skin disorders.

Polyvinylpyrrolidone (commonly known as povidone or PVP) rapidly dissolves in water. This significantly hinders its use in sustained release formulations developed for the biomedical field. Electrospun fibers of PVP dissolve even faster due to larger surface to volume ratio. In this work, we propose a way to circumvent this problem by developing and using functional fibrous materials in hydrogel form. In particular, we demonstrate that ethanolic solutions of PVP containing two hydroxycinnamic acid derivatives, namely p-coumaric and ferulic acids could be electrospun into functional hydrogel fiber mats. After electrospinning, the formed composite mats were first thermally treated at 130 °C for 20 h and subsequently were immersed in aqueous media, where they turned into hydrogels. Thermal annealing did not degrade hydroxycinnamic acid derivatives, preserving their functionality. We propose these hydrogel fiber mats as potential wound dressings and to that end, in vitro tests showed up to 8 days of antioxidants’ release, and consequent protection of A549 epithelial cells against oxidative stresses. Biocompatibility tests using human red blood cells, A549 and HaCaT cell lines indicated no adverse effects. Model studies of mice skin burns induced by UV-B radiation showed that the hydrogel fiber dressings significantly reduced the levels of matrix metallopeptidase, (MMP-9), and glutathione peroxidase 1 (GPX-1), which are usually upregulated by reactive oxidative species on burnt skin. Finally, ex-vivo human skin investigations demonstrated skin regeneration and control of the inflammatory phase as indicated by low levels of pro-inflammatory cytokines (IL-6 and IL-8). Therefore, our outcomes indicate that the developed PVP-based fiber hydrogels, produced using a simple protocol, are promising candidates for active wound dressings.

We report on the synthesis, characterization, and application of biomimetic, spherical Au nanoparticles (AuNPs) coated with keratin (Ker-AuNPs). They are characterized in terms of morphological, spectral, and thermo-optical properties. Besides their excellent colloidal stability, Ker-AuNPs exhibit excellent biocompatibility. The latter is verified by performing viability assay experiments of a strain of Escherichia coli (E. coli) in the presence of Ker-AuNPs as a function of the incubation time. Ker-AuNPs do not affect the E. coli viability and proliferation, even at the highest concentration tested (C = 5.83*10−5 M). Photo-thermal assisted viability experiments are performed by setting the starting temperature at 37 °C, mimicking the normal human body temperature condition. They evidence the capability of the Ker-AuNPs to generate a temperature up to about 73 °C (an increase of 36 °C), thus reducing the viability of bacterial cells 3 order of magnitudes. We also conducted a theoretical analysis with an ad-hoc model that evidences an excellent agreement between theory and experiments. Ker-AuNPs represent a new generation of multifunctional nanotherapeutics, and they constitute a new opportunity in drug-free and minimally invasive biomedical applications.

Keratin extracted from wool fibers has recently gained attention as an abundant source of renewable, biocompatible material for tissue engineering and drug delivery applications. However, keratin extraction and processing generally require a copious use of chemicals, not only bearing consequences for the environment but also possibly compromising the envisioned biological outcome. In this study, we present, for the first time, keratin-PVP biocomposite fibers obtained via an all-water co-electrospinning process and explored their properties modulation as a result of different thermal crosslinking treatments. The protein-based fibers featured homogenous morphologies and average diameters in the range of 170–290 nm. The thermomechanical stability and response to a wet environment can be tuned by acting on the curing time; this can be achieved without affecting the 3D fibrous network nor the intrinsic hydrophilic behavior of the material. More interestingly, our protein-based membranes treated at 170 °C for 18 h successfully sustained the attachment and growth of primary human dermal fibroblasts, a cellular model which can recapitulate more faithfully the physiological human tissue conditions. Our proposed approach can be viewed as pivotal in designing tunable protein-based scaffolds for the next generation of skin tissue growth devices.

Teeth extractions are often followed by alveolar bone reabsorption, although an adequate level of bone is required for reliable rehabilitations by dental implants. Leukocyte and platelet-rich fibrin (L-PRF) has been widely applied in regenerative procedures and with antibiotic and antioxidant agents could play an essential role in hard and soft tissue healing. In this work, a nanocomposite (Sponge-C-MTR) consisting of a hyaluronate-based sponge loaded with metronidazole (MTR) and nanostructured lipid carriers containing curcumin (CUR-NLC) was designed to be wrapped in the L-PRFTM membrane in the post-extraction sockets and characterized. CUR-NLCs, obtained by homogenization followed by high-frequency sonication of the lipid mixture, showed loading capacity (5% w/w), drug recovery (95% w/w), spherical shape with an average particle size of 112.0 nm, and Zeta potential of −24 mV. Sponge-C-MTR was obtained by entrapping CUR-NLC in a hydrophilic matrix by a freeze-drying process, and physico-chemical and cytocompatibility properties were evaluated. Moreover, the aptitude of CUR and MTR to the penetrate and/or permeate both L-PRFTM and porcine buccal tissue was assessed, highlighting MTR penetration and CUR accumulation promoted by the system. The results positively support the action of nanocomposite in dental tissues regeneration when applied together with the L-PRFTM.

A vinyl laurate-based elastomeric copolymer, developed as chewing gum base, was used to produce functional coatings with the antioxidant curcumin. Both the polymer and curcumin were dissolved in MIBK, methyl isobutyl ketone. Coatings were applied on glass but also on natural alginate and gelatin film surfaces by dip-coating. Microscopy analysis indicated that coatings had very homogenous surface and curcumin was effectively encapsulated within the polymeric matrix. In addition, curcumin-laden coatings (10 wt%) remained transparent with excellent UV filtering properties. The flexibility of alginate and gelatin films was maintained after coating, whereas their hydrophobicity and water vapor barrier properties improved. Furthermore, coating biocompatibility and low bacterial adhesion properties were confirmed by cell proliferation and bacterial surface contamination experiments, respectively. The radical scavenging activity of the coating was assessed with both DPPH and ABTS assay, revealing effective antioxidant properties. In addition, in weak acetic acid solutions, curcumin could be released in a sustained manner from the coatings. This coating can be used as a suitable option for improving the antioxidant and bacterial resistance properties of natural polymer films including food packaging or other relevant applications.

Topical treatment of wound infections is often a challenge due to limited drug availability at the site of infection. Topical drug delivery is an attractive option for reducing systemic side effects, provided that a more selective and sustained local drug delivery is achieved. In this study, a poorly water-soluble antibiotic, ciprofloxacin, was loaded on polyvinylpyrrolidone (PVP)-based foils and nanofiber mats using acetic acid as a solubilizer. Drug delivery kinetics, local toxicity, and antimicrobial activity were tested on an ex vivo wound model based on full-thickness human skin. Wounds of 5 mm in diameter were created on 1.5 × 1.5 cm skin blocks and treated with the investigated materials. While nanofiber mats reached the highest amount of delivered drug after 6 h, foils rapidly achieved a maximum drug concentration and maintained it over 24 h. The treatment had no effect on the overall skin metabolic activity but influenced the wound healing process, as observed using histological analysis. Both delivery systems were efficient in preventing the growth of Pseudomonas aeruginosa biofilms in ex vivo human skin. Interestingly, foils loaded with 500 µg of ciprofloxacin accomplished the complete eradication of biofilm infections with 1 × 109 bacteria/wound. We conclude that antimicrobial-loaded resorbable PVP foils and nanofiber mats are promising delivery systems for the prevention or topical treatment of infected wounds.

Microalgae are generally considered an excellent source of vitamins, minerals, and bioactive molecules that make them suitable to be introduced in cosmetics, pharmaceuticals, and food industries. Aphanizomenon flos-aquae (AFA), an edible microalga, contains numerous biomolecules potentially able to prevent some pathologies including age-related disorders. With the aim to include an AFA extract (Klamin®) as a functional ingredient in baked products, we investigated if its bioactive molecules are destroyed or inactivated after standard cooking temperature. The AFA extract was exposed to heat stress (AFA-HS), and no significant decrease in pigment, polyphenol, and carotenoid content was detected by spectroscopic analysis. Thermal stability of AFA-HS extract was demonstrated by thermogravimetric analysis (TGA), and no change in the morphology of the granules of the powder was noticed by SEM microscopic observation. By Folin-Ciocalteu, ORAC, and ABTS assays, no change in the antioxidant activity and polyphenol contents was found after high-temperature exposition. When added in cell culture, solubilized AFA-HS lost neither its scavenging ability against ROS generation nor its protective role against Abeta, the main peptide involved in Alzheimer's disease. Prebiotic and antioxidant activities of AFA extract that are not lost after thermal stress were verified on E. coli bacteria. Finally, AFA-HS cookies, containing the extract as one of their ingredients, showed increased polyphenols. Here, we evaluate the possibility to use the AFA extract to produce functional food and prevent metabolic and age-related diseases.

Polyvinylpyrrolidone (PVP) has probably been one of the most utilized pharmaceutical polymers with applications ranging from a blood plasma substitute to nanoparticle drug delivery, since its synthesis in 1939. It is a highly biocompatible, non-toxic and transparent film forming polymer. Although high solubility of PVP in aqueous environment is advantageous, it still poses several problems for some applications in which sustained targeting and release are needed or hydrophobic drug inclusion and delivery systems are to be designed. In this study, we demonstrate that a common dietary phenolic antioxidant, p-coumaric acid (PCA), can be combined with PVP covering a wide range of molar ratios by solution blending in ethanol, forming new transparent biomaterial films with antiseptic and antioxidant properties. PCA not only acts as an effective natural plasticizer but also establishes H-bonds with PVP increasing its resistance to water dissolution. PCA could be released in a sustained manner up to a period of 3 days depending on the PVP/PCA molar ratio. Sustained drug delivery potential of the films was studied using methylene blue and carminic acid as model drugs, indicating that the release can be controlled. Antioxidant and remodeling properties of the films were evaluated in vitro by free radical cation scavenging assay and in vivo on a murine model, respectively. Furthermore, the material resorption of films was slower as PCA concentration increased, as observed from the in vivo full-thickness excision model. Finally, the antibacterial activity of the films against common pathogens such as Escherichia coli and Staphylococcus aureus and the effective reduction of inflammatory agents such as matrix metallopeptidases were demonstrated. All these properties suggest that these new transparent PVP/PCA films can find a plethora of applications in pharmaceutical sciences including skin and wound care.

Antioxidant fabrics are excellent shields against oxidative damage by free radicals and can be used in clothing, packaging, cosmetics and preservation. In this study, we developed antioxidant and hydrophobic cotton fabrics using ecofriendly materials and processes. The fabrics were functionalized with a double layer coating. Pristine cotton fabrics were coated with a food grade antioxidant (butylated hydroxytoluene, BHT) incorporated biodegradable polyester (polycaprolactone, PCL). This coating was shielded with an acetoxy functional biocompatible hydrophobic silicone coating. The hydrophobic shielding prevented potential loss of the antioxidant due to interaction with water or ambient humidity over time. Coated fabrics were exposed to extreme peroxidative (concentrated H2O2) and UV light damage conditions using an ad hoc protocol for simulating decades of atmospheric ageing. Chemical changes on the cotton surface and potential oxidation and preventive mechanisms were studied using spectroscopy. Treated fabrics also displayed very low water vapor uptake and remained breathable with no visible color change. Mechanical properties of the original fabric were preserved after the treatment.

Mycelia, the vegetative part of fungi, are emerging as the avant-garde generation of natural, sustainable, and biodegradable materials for a wide range of applications. They are constituted of a self-growing and interconnected fibrous network of elongated cells, and their chemical and physical properties can be adjusted depending on the conditions of growth and the substrate they are fed upon. So far, only extracts and derivatives from mycelia have been evaluated and tested for biomedical applications. In this study, the entire fibrous structures of mycelia of the edible fungi Pleurotus ostreatus and Ganoderma lucidum are presented as self-growing bio-composites that mimic the extracellular matrix of human body tissues, ideal as tissue engineering bio-scaffolds. To this purpose, the two mycelial strains are inactivated by autoclaving after growth, and their morphology, cell wall chemical composition, and hydrodynamical and mechanical features are studied. Finally, their biocompatibility and direct interaction with primary human dermal fibroblasts are investigated. The findings demonstrate the potentiality of mycelia as all-natural and low-cost bio-scaffolds, alternative to the tissue engineering systems currently in place.

New sustainable composite materials inspired by plant cuticles have been fabricated by impregnation of fibrous cellulose substrates with a naturally occurring polyhydroxylated fatty acid (9,10,16-trihydroxypalmitic or aleuritic acid) and subsequent polymerization of the latter into polyaleuritate. A two-step preparation method is used, comprising of spraying and hot-pressing. The hot-pressing temperature is critical for the extent of polymerization of polyaleuritate and its alteration allows fine tuning of the mechanical properties, opacity, wettability, and water adsorption of the developed composite materials. The cellulose substrate controls other characteristics such as water permeability and thermal conductivity. Addition of carnauba wax into the polyaleuritate matrix results in improvement of water and oxygen barrier properties. Best results in terms of mechanical resistivity, transparency, water resistance, and low values of oxygen permeability are obtained for samples fabricated using hot-pressing temperature of 200 °C and with a final formulation of 80.6% of cellulose, 17.7% of aleuritic acid, and 1.7% of carnauba wax. Comparison of the composite properties with common plastics confirms that these plant cuticle-like materials can become promising alternatives to petroleum-based macromolecules for packaging applications.

Water insoluble monohydrochloride monohydrate free ciprofloxacin (Cipro) antibiotic was incorporated in polyvinylpyrrolidone (PVP) polymer matrix by using acetic acid co-solvent in water. The resultant solutions were cast into fully transparent antimicrobial films. Proper concentrations of acetic acid eliminated in situ crystallization of the antibiotic and the resultant phase separation upon solvent evaporation. The solutions could also be electrospun into nanofiber mats (non-transparent). Presence of residual PVP-bound acetic acid in dry PVP films induced unprecedented levels of plasticity (stretching capacity) and softness to the films. Additionally, PVP-bound acetic acid also acted as an antiseptic. Antibacterial properties of the films and fiber mats were confirmed on Escherichia coli and Bacillus subtilis (growth and viability). Films and nanofiber mats demonstrated promising wound resorption characteristics by using in vivo full-thickness excisional skin wound healing mice model. Nanofiber mats were resorbed much faster than transparent films. Wound exudate absorption in the films and resorption rate of the nanofiber mats were dependent on the starting acetic acid concentrations. The fact that PVP/Cipro solutions in aqueous acetic acid can be used either to produce transparent soft films or nanofiber mats renders this process highly suitable for the fabrication of new-generation potential dressings for wound management and care.

ϵ-caprolactone-p-coumaric acid copolymers at different mole ratios (ϵ-caprolactone:p-coumaric acid 1:0, 10:1, 8:1, 6:1, 4:1, and 2:1) were synthesized by melt-polycondensation and using 4-dodecylbenzene sulfonic acid as catalyst. Chemical analysis by NMR and GPC showed that copolyesters were formed with decreasing molecular weight as p-coumaric acid content was increased. Physical characteristics, such as thermal and mechanical properties, as well as water uptake and water permeability, depended on the mole fraction of pcoumaric acid. The p-coumarate repetitive units increased the antioxidant capacity of the copolymers, showing antibacterial activity against the common pathogen Escherichia coli. In addition, all the synthesized copolyesters, except the one with the highest concentration of the phenolic acid, were cytocompatible and hemocompatible, thus becoming potentially useful for skin regeneration applications.

Similar to pharmaceutical products, medical devices play an increasingly important role in healthcare worldwide by contributing substantially to the prevention, diagnosis and treatment of diseases. From the patent law perspective both, pharmaceutical products and a medical apparatus, product or device can be patented if they meet the patentability requirements, which are novelty, inventivenes

After a skin injury, many complex metabolic events are triggered to ensure proper wound healing. Particularly for chronic, non-healing wounds or burns several risk factors such as persistent bacterial infections and fast dehydration can counteract the healing process. Intelligent wound dressings should help accelerate the healing process, while maintaining the wound bed clean and disinfected for several days at a time. Ideally, they should be self-adherent to both moist and dry skin surfaces and be transparent enough to allow prolonged wound inspection. These requirements pose challenges both in terms of materials science and pharmaceutics. Herein, we describe fabrication of a transparent bilayer construct for the sequential release and delivery of a cutaneous antiseptic and a widely used antibiotic, potentially suitable for wound dressing applications. The fabrication is a scalable waterborne and ecofriendly solution casting process. The first layer (for direct wound contact) is polyvinylpyrrolidone (PVP) containing a commercial antiseptic, Neomercurocromo® (Neo), while the second layer is a blend of hyaluronic acid (HA) and PVP containing ciprofloxacin. We show that the bilayer films have satisfactory self-adhering strength to human skin and that PVP and HA can interact via hydrogen bonds causing sustained release of the antibiotic over a period of 5 days. Biocompatibility was demonstrated on human foreskin fibroblast HFF-1 cells. Antibacterial activity was evaluated against Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa while the wound resorption behavior was assessed through an in vivo full-thickness excisional wound healing mice model. These observations indicate that such bilayer constructs can be potentially implemented as wound care products for diverse range of skin wounds, including large area skin infections.

Polyvinylpyrrolidone (PVP) has probably been one of the most utilized pharmaceutical polymers with applications ranging from a blood plasma substitute to nanoparticle drug delivery, since its synthesis in 1939. It is a highly biocompatible, non-toxic and transparent film forming polymer. Although high solubility of PVP in aqueous environment is advantageous, it still poses several problems for some applications in which sustained targeting and release are needed or hydrophobic drug inclusion and delivery systems are to be designed. In this study, we demonstrate that a common dietary phenolic antioxidant, p-coumaric acid (PCA), can be combined with PVP covering a wide range of molar ratios by solution blending in ethanol, forming new transparent biomaterial films with antiseptic and antioxidant properties. PCA not only acts as an effective natural plasticizer but also establishes H-bonds with PVP increasing its resistance to water dissolution. PCA could be released in a sustained manner up to a period of 3 days depending on the PVP/PCA molar ratio. Sustained drug delivery potential of the films was studied using methylene blue and carminic acid as model drugs, indicating that the release can be controlled. Antioxidant and remodeling properties of the films were evaluated in vitro by free radical cation scavenging assay and in vivo on a murine model, respectively. Furthermore, the material resorption of films was slower as PCA concentration increased, as observed from the in vivo full-thickness excision model. Finally, the antibacterial activity of the films against common pathogens such as Escherichia coli and Staphylococcus aureus and the effective reduction of inflammatory agents such as matrix metallopeptidases were demonstrated. All these properties suggest that these new transparent PVP/PCA films can find a plethora of applications in pharmaceutical sciences including skin and wound care.