Covalently bound self-passivating silica layer enhances polyetherimide stability in harsh space conditions Lidia Mezzina, Angelo Nicosia, Prospero Savoca, Maria Elisabetta Palumbo, Carlotta Scirè, Riccardo Giovanni Urso, Giuseppe Antonio Baratta, Anna Lucia Pellegrino, Laura Barone, Placido Mineo Polymer Degradation and Stability, 2026 • PEI can be damaged by fast solar ions impact, affecting its durability • Silanization of the PEI surface was performed to obtain a self-passivating system • rPAA@TEOS showed compact and uniform surface after high-energy proton bombardment • The dose value of our laboratory experiments is similar to about 3 years in GEO. The rapid expansion of human space exploration highlights the need for advanced materials capable of enduring the severe conditions of extraterrestrial environments. Polymeric materials, such as polyetherimide (PEI), are extensively used in aerospace applications due to their low density, mechanical versatility, and partial shielding capacity against radiation. Nevertheless, prolonged exposure to hostile factors such as galactic cosmic rays, solar energetic particles, solar wind ions, atomic oxygen, and electromagnetic radiation results in progressive structural degradation manifested as erosion, mass loss, and deterioration of mechanical, thermal, and optical properties. To mitigate these effects, inorganic protective layers, particularly metal oxides, have been investigated because of their high hardness, chemical stability, and erosion resistance. Despite these advantages, issues related to interfacial adhesion and long-term stability of such protective layers remain significant challenges. The present study reports a novel covalent silica-based passivation approach for PEI, achieved through a multi-step chemical functionalization of the polymer surface. The process involves: i) the partial hydrolysis of imidic ring on PEI film surface, forming polyamic acid (PAA) layer; ii) chemical reduction of the carboxylic acid of PAA to benzylic alcohol groups; iii) grafting tetraethyl orthosilicate to benzyl alcohol moieties. The procedures were monitored using ATR-FT-IR, DSR-UV-Vis, contact angle, and SEM-EDX analyses. To evaluate the shielding efficacy of the obtained system, both pristine PEI and silica-coated PEI samples were exposed to simulated fast solar ions flux. The experimental results confirm the increased resistance to erosion of the silica shielded material compared to that of untreated PEI. Finally, to assess the applicability of the material in real-scenarios, a computer simulation was performed to estimate the energy dose for the proposed material as a function of the radius for different space orbits.
A bio-based curcumin copolymer for the detection of volatile amines Angelo Nicosia, Lidia Mezzina, Placido Mineo Progress in Organic Coatings, 2026 A copolymeric sensor containing Zn(II)-Curcumin derivatives as the sensing unit was developed via a bottom-up strategy. Specifically, a vinyl acetate/acrylic acid polymeric backbone was synthesized through radical bulk polymerization and covalently linked to Curcumin using a catalyzed esterification method, and the resultant system was subsequently metalated with Zn(II) cations. The Curcumin loading on the polymer backbone was approximately 2.22 %wt. The copolymers were characterized by Gel Permeation Chromatography, 1 H NMR, UV–Vis, and fluorescence spectroscopies, Thermogravimetric analysis, and Differential Scanning Calorimetry. The spectroscopic properties of the produced systems, deposited as solid-state thin films, were analyzed with Diffuse Reflectance UV–Vis Spectroscopy. The sensing capability was investigated via experiments involving volatile model pollutants (ethanol, toluene, acetone, ethylenediamine, pyridine, and ammonia), with the sensor thin films exposed to the headspace of a vial containing these pollutants. The sensor demonstrated sensitivity to model pollutants such as ammonia, ethylenediamine, and pyridine, while showing negligible variations to nonpolar and less nucleophilic species. The proposed methodology allows the development, including on an industrial scale, of a facile and cost-effective detector for polar volatile organic compounds. To the best of our knowledge, this represents the first application of Zn-Curcumin derivatives within colorimetric sensing contexts. • A Copolyvinyl acetate-Acrylic acid covalently attached to Zn-Curcumin complex was developed. • The Curcumin loading on the polymer backbone was approximately 2.22 %wt. • The polymeric sensor shows colorimetric response towards gaseous amines. • The magnitude of the spectroscopic shift was proportional to the nucleophilic behavior of the amine pollutant.
Chiral Fluorescent Uranyl-Salen Oligomer for Enantiomeric Supramolecular Recognition of Tryptophan Andrea Pappalardo, Angelo Nicosia, Aurore Fraix, Rossella Santonocito, Placido Mineo, Giuseppe Trusso Sfrazzetto Current Organic Chemistry, 2026 introduction: The development of enantioselective fluorescent sensors is of great interest for the detection of biologically relevant molecules such as amino acids. Tryptophan (Trp), in particular, plays a critical role in biochemical processes, and its selective recognition remains a challenging task. In this study, we report the synthesis and characterization of a new chiral oligomer based on an oligo-(p‑phenyleneethynylene) backbone functionalized with multiple Lewis acidic metal centers—specifically uranyl ions. This system represents the first example of a uranyl-salen oligomer exhibiting strong fluorescence and high selectivity toward Trp. materials and methods: The chiral oligomer was synthesized via a stepwise coupling of p‑phenyleneethynylene units, followed by complexation with uranyl ions to introduce Lewis acidic centers. The resulting oligomer was characterized using NMR, UV-Vis, fluorescence spectroscopy, and mass spectrometry. Enantioselective binding studies were conducted by fluorescence titration using L- and D-tryptophan. The formation of supramolecular assemblies upon Trp recognition was investigated by dynamic light scattering (DLS) to assess changes in particle size. results: The resulting uranyl-functionalized oligomer displayed significant fluorescence, making it the first example of a fluorescent uranyl-oligomer of this kind. The sensor demonstrated a high affinity for L-tryptophan, with an enantiodiscrimination ratio exceeding 40:1 over the D-enantiomer. The limit of detection was found to be in the sub-ppm range. DLS analysis confirmed the formation of micrometer-sized aggregates upon interaction with Trp, indicating non-covalent host–guest interactions and supramolecular organization. discussion: The unique conjugated structure of the oligomer, combined with the Lewis acidity of uranyl centers, provides a synergistic effect for selective and sensitive detection of L-tryptophan. The significant enantioselectivity observed suggests a specific chiral environment within the oligomeric scaffold, which is not replicated for the D-isomer. The fluorescence response and aggregation behavior further support the role of Trp in driving the formation of higher-order structures through molecular recognition. conclusion: This study presents the first fluorescent uranyl-salen oligomer capable of selectively recognizing L-tryptophan with high sensitivity and enantioselectivity. The system offers new insights into the design of supramolecular sensors based on metal-organic oligomers and opens new avenues for the development of chiral sensing platforms targeting biologically important molecules.
Protoporphyrin-grafted halloysite nanotubes for boosted photodynamic activity in chitosan nanocomposite films Marina Massaro, Federica Leone, Angelo Nicosia, Giuseppe Lazzara, Giuseppe Cavallaro, et al. Applied Clay Science, 2025 Chitosan-based materials are widely explored for biomedical applications due to their biocompatibility, biodegradability, and excellent film-forming ability. In this work, we report the development of hybrid chitosan films reinforced with halloysite nanotubes (Hal) covalently functionalized with protoporphyrin IX (PPIX), aiming to enhance their photodynamic properties. Photodynamic therapy (PDT) has emerged as a promising and minimally invasive technique for cancer treatment due to its selectivity and low toxicity. However, the clinical use of many photosensitizers, such as PPIX, is limited by their poor solubility in water. The covalent anchoring of PPIX onto the external surface of Hal significantly improved its availability in water, which was further enhanced upon coordination with Zn 2+ ions. The resulting Hal-PPIX nanomaterials were characterized by spectroscopic and microscopic techniques and evaluated, both chemically and biologically, for their ability to generate reactive oxygen species (ROS) under visible light irradiation. As proof of concept, the nanomaterials were incorporated into chitosan films and studied for their mechanical properties and AFM was employed to investigate the surface morphology of them. The results demonstrate the potential of these bio-based nanocomposites as promising candidates for topical photodynamic therapy, particularly in skin cancer treatment. • Hal was covalently functionalized with protoporphyrin IX (PPIX) and PPIX@Zn. • The resulting nanomaterials efficiently generated singlet oxygen under visible light irradiation. • They exhibited phototoxic effects against multidrug-resistant leukemia cells. • The nanomaterials were used as fillers for chitosan matrix. • Results show the potential of the nanocomposites as promising candidates for topical PDT.
Amphiphilic cyclodextrin-based nanocarriers for magnetic delivery of a morphogen in microfluidic environments Alessandro Surpi, Roberto Zagami, Marianna Barbalinardo, Nina Burduja, Giuseppe Nocito, Riccardo Di Corato, Maria Pia Casaletto, Francesco Valle, Angelo Nicosia, Placido Giuseppe Mineo, Valentin Alek Dediu, Antonino Mazzaglia Materials Advances, 2025 A supramolecular assembly based on a cyclodextrin-based nanocarrier hosting superparamagnetic nanoparticles and retinoic acid can be magnetically guided through microfluidic environments to induce differentiation of SH-SY5Y cells therein cultured.
Copolyformals containing metalloporphyrins as solid optical probes for amines detection Lidia Mezzina, Angelo Nicosia, Placido G. Mineo Dyes and Pigments, 2025 A polymer-based sensor incorporating porphyrin species as the sensing unit, which makes it able to detect different volatile organic compounds (VOCs) of environmental and industrial relevance, was developed by synthesizing copolyetherformals with metalloporphyrin units in the main chain. Particularly, the Zinc and Cobalt -porphyrins were produced by metalation of the porphyrin moiety into the copolyetherformal. The structural and chemical-physical features of the obtained systems were investigated by means of MALDI-TOF mass spectrometry, gel permeation chromatography, UV–Vis, fluorescence and nuclear magnetic resonance spectroscopies, as well as thermoanalyses techniques. The sensing properties of the copolymers were evaluated in toluene solutions and in solid-state thin film. In solution, the zinc-porphyrin-containing copolymer exhibited a linear response in the range of 60 μM to 0.7 mM for pyridine and approximately 1.1 μM–60 μM for piperidine. The cobalt-porphyrin-containing copolymer exhibited a linear response in the range of approximately 0.3 μM–30 μM for pyridine and about 0.09 μM–18 μM for piperidine. The performance of the sensors was further investigated in the solid state by exposing the thin films of the copolymer sensors to VOCs, showing sensing features towards the amine species and no sensing activity towards the ethers and aromatic nonpolar species. These findings underline the potential of metalloporphyrin-polymeric systems as versatile and highly sensitive materials for VOCs optical sensing applications. • Zinc and Cobalt porphyrins containing copolyetherformals are synthetized. • The spectroscopic features of metalloporphyrins are retained in the copolymers. • Thin films of metalloporphyrin based copolymers work as solid-state sensors of pollutants. • Copolymeric sensors show a linear response to amine-based species. • Sensor systems showed reversibility up to three cycles.
Covalently Functionalized Halloysite-Calixarene Nanotubes for Injectable Hydrogels: A Multicavity Platform for Hydrophobic Drug Delivery Giuseppe Cinà, Marina Massaro, Andrea Pappalardo, Carmela Bonaccorso, Cosimo G. Fortuna, Placido G. Mineo, Angelo Nicosia, Paola Poma, Rita Sánchez-Espejo, Caterina Testa, César Viseras, Serena Riela Pharmaceuticals, 2025 Background: Poor water solubility is a major limitation for the therapeutic use of many anticancer drugs. In this study, we report the design and development of two halloysite-based hybrid nanomaterials for the encapsulation and delivery of hydrophobic and positively charged drugs. Methods: A novel multicavity platform was obtained by covalently grafting calix[5]arene macrocycles onto the external surface of halloysite nanotubes (HNTs), combining lumen encapsulation with supramolecular host–guest recognition. PB4, a planar and hydrophobic pyridinium salt with significant antiproliferative activity, was selected as a model compound. Both PB4-loaded HNTs (HNTs/PB4) and calixarene-functionalized HNTs (HNTs-Calix/PB4) were incorporated into Laponite®-based thixotropic hydrogels to obtain injectable and biocompatible systems. Results: The nanomaterials were thoroughly characterized, and their loading efficiency, release behavior, and aqueous dispersibility were evaluated. Antiproliferative tests on MCF-7 cells demonstrated that both hydrogels retained PB4 activity, with distinct release profiles: the pristine HNTs allowed faster drug availability, while calix[5]arene-functionalized systems promoted sustained release. Conclusions: This work introduces the first example of covalently calixarene-functionalized halloysite and presents a versatile drug delivery platform adaptable to different therapeutic contexts and combination strategies.
A supramolecular assembly made with sulfobutylether-β-cyclodextrin and magnetic Fe3O4 showing water remediation properties Nina Burduja, Giuseppe Nocito, Mariachiara Trapani, Alberto Riminucci, Riccardo Di Corato, Antonio Della Torre, Angelo Nicosia, Antonino Gulino, Placido Giuseppe Mineo, Antonino Mazzaglia Journal of Molecular Liquids, 2025 • Self-assembly between iron oxide nanoparticles (MNPs) and sulfobutylether β-cyclodextrin (Captisol). • The MNPs@Captisol assembly was characterized by TGA, spectroscopic (FT-IR, XPS, μXRF) and imaging (TEM) techniques, mass magnetization, DLS analysis and an adapted turbidimetric method. • The assembly shows water remediation properties towards paraquat, a model positive-charged pollutant. • The sequestering mechanism was related to electrostatic complexation. In literature many examples of magnetic nanohybrids based on cyclodextrins are reported, but they often require multistep processes and preliminary synthetic efforts that affect the scale-up for the final application. In this paper, a magnetic hybrid system was produced by supramolecular self-assembly between low-cost precursors: the sulfobutylether-β-cyclodextrin (Captisol®) and magnetic iron oxide-based nanoparticles (MNPs). The interaction between the Captisol® and MNPs was elucidated by spectroscopic (Fourier Transform Infrared − FT-IR, X-ray Photoelectron Spectroscopy – XPS, micro X-ray fluorescence – μXRF) and imaging (Transmission Electron Microscopy − TEM) techniques. The resulting MNPs@Captisol assembly was also characterized by thermogravimetric analysis to establish the amount of the organic moiety. The colloidal features were evaluated by dynamic light scattering measurements and an adapted turbidimetric analysis. Finally, a promising use of MNPs@Captisol as remediation agent against paraquat (chosen as a model of cationic pollutant), has been demonstrated. The sequestering mechanism, depending on the concentration and by electrostatic interactions, was ascertained.
Halloysite Nanotubes Functionalized with Naphthalene Diimide and Peptide Nucleic Acid Derivatives: Toward Multifunctional Nanomaterials Francesca Cardano, Marina Massaro, Federica Leone, Giuseppe Cinà, Nicola Borbone, Andrea P. Falanga, Giorgia Oliviero, Angelo Nicosia, Martina Fresia, Andrea Fin, Vittorio Scardaci, Raquel de Melo Barbosa, Serena Riela ACS Applied Nano Materials, 2025 The development of multifunctional nanomaterials is an area of growing interest, particularly for systems that integrate optical and molecular recognition capabilities. Halloysite nanotubes (HNTs) provide a versatile platform for functionalization owing to their unique tubular structure and distinct inner and outer surface chemistry. In this study, we report the synthesis and characterization of HNTs-based nanomaterials functionalized with naphthalene diimide derivatives (NDIs) and peptide nucleic acid (PNA). NDIs were covalently anchored onto the external surface of HNTs to enhance their solubility and photophysical properties, while a model PNA sequence was incorporated to explore the suitability of NDI-functionalized HNTs as an efficient platform for the delivery of molecular probes. The synthesized nanomaterial was thoroughly characterized through morphological (HAADF/STEM), spectroscopic (UV–vis, fluorescence, FT-IR), and thermal (TGA) analyses. The results confirm the successful functionalization of HNTs, demonstrating the tunability of their optical properties and the effective integration of the PNA. This study provides insights into the engineering of hybrid nanomaterials with potential applications in molecular recognition, sensing, and advanced material design.
