Norma Mallegni

The development of antibacterial cotton textiles is of considerable interest for applications in healthcare, hygiene, and protective materials, where limiting microbial proliferation on fibrous surfaces is essential. However, many of the finishing strategies currently reported for cotton rely on metal-based agents or multifunctional synthetic systems, which may raise concerns about environmental impact, uncontrolled release, and long-term durability. In this context, the use of naturally derived bioactive compounds, combined with surface activation methods, represents a promising route toward more sustainable antimicrobial coatings. In this study, cotton fabrics were functionalized with a commercial biobased acrylic resin that contained increasing amounts of rosmarinic acid, a plant-derived polyphenol with recognized antimicrobial activity. The effect of oxygen plasma pretreatment was investigated to assess whether surface activation could improve coating distribution, interfacial adhesion, and functional performance. Resin films and coated fabrics were characterized by infrared spectroscopy, thermogravimetric analysis, differential scanning calorimetry, and scanning electron microscopy, while antibacterial activity was evaluated against Staphylococcus aureus and Escherichia coli. The results showed that plasma pretreatment promoted a more homogeneous distribution of the coating on cotton and qualitatively supported a more effective organization of the resin-based functional layer. The incorporation of rosmarinic acid modified the thermal behavior of the resin, indicating reduced chain mobility and more importantly the occurrence of interaction with the polymer matrix. The coated fabrics displayed marked antibacterial activity against S. aureus, whereas the effect against E. coli was more strongly dependent on rosmarinic acid content and coating uniformity. Overall, the study demonstrates that combining plasma surface activation with a biobased resin containing rosmarinic acid is a viable strategy for preparing metal-free antibacterial cotton coatings.

Molecular imprinting is a powerful strategy for fabricating synthetic materials with selective recognition toward specific biomolecules. In this work, molecularly imprinted (MIM) membranes based on poly (ethylene-co-vinyl alcohol) (EVAL) were developed for selective protein recognition and conformational modulation using α-amylase as a model template. Membranes were prepared by phase inversion, generating porous structures suitable for mass transport and adsorption. Template extraction, measured using UV–Vis spectroscopy, showed a rapid and effective removal of α-amylase while preserving membrane morphology, as confirmed by SEM. FTIR-ATR and chemical imaging confirmed template removal from the membrane and a uniform surface distribution of rebound α-amylase after successive template incubation. Rebinding experiments showed a concentration-dependent uptake of α-amylase and an apparent saturation trend at higher concentrations. Selectivity tests using bovine serum albumin as an analog confirmed preferential recognition of α-amylase. Enzymatic assays showed partial recovery of catalytic activity after rebinding of thermally denatured α-amylase, indicating that imprinted cavities may promote protein conformational reorganization. These results highlight the potential of EVAL-based imprinted membranes as biomimetic platforms for selective protein recognition and functional modulation.

In this work, gellan gum microspheres (G–MPs) were developed as delivery systems for blueberry extract (Vaccinium myrtillus) (BEX), a source of natural antioxidants rich in anthocyanins (ATCs) and phenolic compounds (PHCs). Gellan gum, an anionic polysaccharide produced via fermentation by Sphingomonas elodea, was selected for its biocompatibility and gelling properties. BEX was obtained using a mild citric acid–based extraction method to preserve antioxidant capacity and was characterized for its total polyphenol, flavonoid, and anthocyanin content before loading. The extract was loaded into gellan gum microspheres via absorption (G–MPs–BEX). The resulting microspheres exhibited a spherical and porous morphology that favoured both encapsulation and controlled release. FT–IR analysis confirmed the absorption of the extract within the polymer network and revealed hydrogen bonding interactions between the matrix and active compounds. Despite these interactions, microspheres retained a high swelling capacity and enabled rapid release, with maximum release of polyphenols and anthocyanins within 30 min at pH 5.5. The antioxidant activity of BEX, assessed via DPPH assay, remained stable during storage (up to 60 days) and after incorporation into the microspheres. Overall, this study demonstrates that G–MPs can efficiently absorb, stabilize, and release natural antioxidant compounds, supporting their potential use in biomedical, nutraceutical, and cosmetic applications.

Polylactic acid (PLA) is a promising biobased polymer celebrated for its biocompatibility, biodegradability, and advantageous mechanical properties. However, its inherent hydrophobicity and lack of hydrophilic functional groups restrict its application in advanced uses, such as nonwoven fabrics (NWFs) for masks, diapers, and biomedical products. This study explores the application of cold plasma treatments to modify the surface of PLA-based NWFs using oxygen and oxygen–argon gas mixtures. We varied power levels and exposure times to optimize surface activation. The samples treated with plasma under different conditions were analyzed to understand the impact of these treatments on the surface functionalization, morphology, and thermal properties of PLA_NWF. Additionally, as a proof of concept, the plasma-treated samples were dip-coated in green tea extract, which is rich in (-)-epigallocatechin gallate (EGCG), a natural antioxidant. The findings demonstrate that plasma treatment significantly enhances the adhesion and functionality of the active ingredient, thereby paving the way for innovative sustainable applications of surface-activated PLA-NWFs in the biomedical and cosmetic sectors or food preservation.

In this work, by-products from insect farming valorisation are proposed as filler in biocomposite production, with relevant biodegradation in compost and valuable thermal and mechanical properties. Thus, we report on the preparation, properties, and biodegradability in compost of composites based on Poly(butylene succinate-co-adipate) (PBSA) and Poly(3-hydroxybutyrate-3-hydroxyvalerate) (PHB-HV) (70/30% by weight as a polymeric matrix, with filler from insect exoskeleton (I) up to 15% by weight in the 85% by weight of polymeric matrix. The insect biomass was a by-product obtained from grinding the insect’s post-protein extraction dry exoskeleton. The composites were produced by melt extrusion and characterised in terms of processability, thermal stability, morphology, and mechanical properties to select formulations optimised for injection moulding processing. The optimised composites (PBSA/PHB-HV) with 15% by weight of filler were used to produce pots by injection moulding on an industrial scale extruder. Selected formulations were tested for biodegradability in compost, which evidenced the relevance of insect exoskeleton filler for meeting the requirements for the disintegration of rigid items. This paper presents a sustainable option for valorising the insect exoskeleton residue that remained after protein extraction for animal feed production and reducing the production cost of PBSA/PHB-HV-based composites without compromising the mechanical properties for application as rigid items in agriculture, all while promoting biodegradability in industrial compost.

In this work are reported preparation, properties and biodegradability in different environments of composites based on Poly (butylene succinate-co-adipate) (PBSA) and Poly(3-hydroxybutyrate-3-hydroxyvalerate) (PHB-HV) as polymeric matrix, with filler from insect exoskeleton (I), a by-product obtained from grinding the insect’s post-protein extraction dry biomass. The composites were produced by melt extrusion and characterized in terms of processability, thermal stability, morphology, and me-chanical properties to select formulations optimized for injection moulding processing. The optimised composites (PBSA/PHB-HV) with different amounts of insect filler (I) were used to produce pots by injection moulding. Selected formulations were tested for biodegradability in compost, home compost and soil. This study presents a sustainable option for valorising the insect exoskeleton residue remaining after protein extraction for animal feed production, and reducing the production cost of PBSA/PHB-HV based composites without compromising mechanical properties for application as rigid items in agriculture, while promoting biodegradability in industrial compost.

The depletion of fossil fuels and environmental concerns have driven the development of sustainable materials, including bio-based and biodegradable plastics, as alternatives to conventional plastics. Although these plastics aid in waste management and climate change mitigation, their vulnerability to oxidative degradation impacts their longevity, durability, and performance. Natural antioxidants such as tocopherols, flavonoids, and tannins, extracted from plants or agri-food waste, present a sustainable alternative to synthetic stabilizers by enhancing the oxidative thermal stability of polymers like poly(lactic acid) (PLA), poly(butylene succinate) (PBS), poly(butylene succinate-adipate) (PBSA), poly(butylene adipate-co-terephthalate) (PBAT), poly(hydroxyalkanoate) (PHA), and starch-based materials. This review highlights recent advances in bio-based plastics stabilized with natural antioxidants, their mechanisms of action, and their role in improving material properties for applications like packaging. Additionally, it explores their impact on recycling processes, advancements in composite production techniques, and future research directions. Bioplastics can achieve enhanced performance, reduce waste, and support a circular economy by incorporating natural antioxidants.

Type-1 diabetes is one of the most prevalent metabolic disorders worldwide. It results in a significant lack of insulin production by the pancreas and the ensuing hyperglycemia, which needs to be regulated through a tailored administration of insulin throughout the day. Recent studies have shown great advancements in developing an implantable artificial pancreas. However, some improvements are still required, including the optimal biomaterials and technologies to produce the implantable insulin reservoir. Here, we discuss the employment of two types of cyclic olefin copolymers (Topas 5013L-10 and Topas 8007S-04) for an insulin reservoir fabrication. After a preliminary thermomechanical analysis, Topas 8007S-04 was selected as the best material to fabricate a 3D-printed insulin reservoir due to its higher strength and lower glass transition temperature (T_g). Fiber deposition modeling was used to manufacture a reservoir-like structure, which was employed to assess the ability of the material to prevent insulin aggregation. Although the surface texture presents a localized roughness, the ultraviolet analysis did not detect any significant insulin aggregation over a timeframe of 14 days. These interesting results make Topas 8007S-04 cyclic olefin copolymer a potential candidate biomaterial for fabricating structural components in an implantable artificial pancreas.

Acoustic signals are important markers to monitor physiological and pathological conditions, e.g., heart and respiratory sounds. The employment of traditional devices, such as stethoscopes, has been progressively superseded by new miniaturized devices, usually identified as microelectromechanical systems (MEMS). These tools are able to better detect the vibrational content of acoustic signals in order to provide a more reliable description of their features (e.g., amplitude, frequency bandwidth). Starting from the description of the structure and working principles of MEMS, we provide a review of their emerging applications in the healthcare field, discussing the advantages and limitations of each framework. Finally, we deliver a discussion on the lessons learned from the literature, and the open questions and challenges in the field that the scientific community must address in the near future.

In the perspective of producing a rigid renewable and environmentally friendly rigid packaging material, two comb-like copolymers of cellulose acetate (AC) and oligo(lactic acid) OLA, feeding different percentages of oligo(lactic acid) segments, were prepared by chemical synthesis in solvent or reactive extrusion in the melt, using a diepoxide as the coupling agent and were used as compatibilizers for poly(lactic acid)/plasticized cellulose acetate PLA/pAC blends. The blends were extruded at 230 °C or 197 °C and a similar compatibilizing behavior was observed for the different compatibilizers. The compatibilizer C1 containing 80 wt% of AC and 14 wt% of OLA resulted effective in compatibilization and it was easily obtained by reactive extrusion. Considering these results, different PLAX/pAC(100-X) compounds containing C1 as the compatibilizer were prepared by extrusion at 197 °C and tested in terms of their tensile and impact properties. Reference materials were the uncompatibilized corresponding blend (PLAX/pAC(100-X)) and the blend of PLA, at the same wt%, with C1. Significant increase in Young’s modulus and tensile strength were observed in the compatibilized blends, in dependence of their morphologic features, suggesting the achievement of an improved interfacial adhesion thanks to the occurred compatibilization.