Flexible or fortified? How lichens balance defence strategies across climatic harshness gradients

New Phytologist, Journal Year: 2025, Volume and Issue: unknown

Published: Jan. 10, 2025

Summary Lichens play important roles in habitat formation and community succession polar alpine ecosystems. Despite their significance, the ecological effects of lichen traits remain poorly researched. We propose a trait trade‐off for managing light exposure based on climatic harshness. In harshest cold environments, where abiotic stress predominates over biotic pressures, lichens should rely photostable, recalcitrant immobile substances such as allomelanin hydrophobic compounds. These compounds provide durable protection without need continual synthesis. milder conditions interactions – e.g. competition pathogen presence become increasingly pronounced, retain flexibility produce simple protective secondary that, addition to functioning screens, can leach out influence direct environment. Preliminary empirical findings Antarctic species distribution are consistent with this hypothesised trade‐off, that producing soluble dominate regions less represented at higher southern latitudes, insoluble melanised thallus dominate. As climate change progresses, increasing temperatures precipitation could make currently coldest driest areas more hospitable, allowing ranges expand, cascading rock weathering, nutrient cycling other ecosystem processes.

Language: Английский

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Multifunctional Thick Films Obtained by Electrodeposition of 1,8-Dihydroxynaphtalene, an Allomelanin Precursor

Langmuir, Journal Year: 2025, Volume and Issue: unknown

Published: Feb. 3, 2025

The deposition of conformal films from redox-active biological molecules, such as catechols, catecholamines, and other polyphenols, has demonstrated great versatility in terms the substrate used. Precursors allomelanins, mainly found plants fungi, have been largely overlooked precursors for design robust coatings. Moreover, their potential application electrodeposition on conductive substrates not yet investigated. Here, by cyclic voltammetry chronoamperometry 1,8-dihydroxynaphthalene (1,8-DHN), a precursor allomelanin, onto gold electrodes Co-Cr alloys aqueous solution-ethanol mixtures yields with sweep rate tunable thickness swelling. resulting are antioxidants, reservoir antioxidant moieties is limited to surface but also extends into bulk film. In addition, produced after energy supply (in window -1 +1 V vs Ag/AgCl) strongly antimicrobial against two strains Pseudomonas aeruginosa without further post-deposition treatment. mechanical properties allow them be detached free-standing films, opening avenues diverse applications biomedicine, storage, catalysis, sensing, optoelectronics.

Language: Английский

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Photochemical Pathways and Light-Enhanced Radical Scavenging Activity of 1,8-Dihydroxynaphthalene Allomelanin

Journal of the American Chemical Society, Journal Year: 2025, Volume and Issue: unknown

Published: March 7, 2025

Melanins play important roles in nature, particularly coloration and photoprotection, where interaction with light is essential. Biomimetic melanins represent an advantageous alternative to natural melanin for technological applications, sharing the same unique biocompatibility, as well optoelectronic properties. Allomelanin, derived from 1,8-dihydroxynaphthalene, has been reported exhibit even better photoprotective antioxidant properties than most studied example of biomimetic melanin, polydopamine. However, allomelanin remains largely unexplored. Here we report excited state dynamics a wide range time windows femtoseconds microseconds minutes, using different experimental techniques, i.e., ultrafast transient absorption, nanosecond X-band electron paramagnetic resonance radical quenching assays. We find that photophysics starkly differs widely polydopamine, broadband excitonically coupled states funneling absorbed energy lower species less 1 ps. Independent excitation wavelength, long-lived (>450 μs) photoproduct populated ≈24 Quantum chemistry calculations suggest primarily exhibits character localized 1,8-naphthoquinone anions. This light-driven increase anionic semiquinone-like concentration enhances activity allomelanin. These results two mechanisms considered at basis light-extinction action, are indeed synergistic not independent, paving way new applications nanomedicine, photocatalysis, conversion environmental remediation.

Language: Английский

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Framework-Imprint Synthesis of Faceted Hierarchical Porous Organic Polymer Colloidal Particles

Nano Letters, Journal Year: 2025, Volume and Issue: unknown

Published: April 16, 2025

Amorphous porous organic polymers (POPs) are promising filler materials for mixed matrix membranes (MMMs). However, it is challenging to synthesize nanosized, monodispersed POP colloidal particles (CPs) suitable membrane fabrication. Here, well-defined octahedral CPs with imine, ketone, or amine linkages were synthesized using MOF as sacrificial templates. In addition shape replication, the template also played a substantial role in spatially organizing polymer chains, resulting highly POPs that unattainable through bulk polymerization. For first time, mechanical properties of single CP was examined by quantitative situ compression testing under scanning electron microscope. Introducing imine-linked into polyimide led series pure-organic defect-free MMMs exhibiting excellent homogeneity and flexibility. As result, increasing loading stepwise increase CO2 permeability largely unchanged CO2/N2 CO2/CH4 selectivity.

Language: Английский

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Melanin‐Driven Green Synthesis and Surface Modification of Metal and Metal‐Oxide Nanoparticles for Biomedical Applications

Advanced Functional Materials, Journal Year: 2025, Volume and Issue: unknown

Published: May 16, 2025

Abstract Tremendous research efforts have recently been devoted to designing and developing melanin‐engineered metal metal‐oxide nanoparticles with unconventional configurations for groundbreaking applications in biomedical settings. These surface‐engineered occupy a unique niche among nanomaterials due the distinctive merits of melanin, such as exceptional biocompatibility, photophysical adaptability, robust metal‐binding capabilities. This review provides comprehensive heuristic overview sustainable synthesis strategies structurally tunable that can facilitate controlled customization melanin. Recent is highlighted harnesses physical properties melanin explore how controlling its geometrical features increase catalytic activity, which essential improving imaging resolution therapeutic efficacy. Furthermore, complex dynamics oxidative polymerization detailed investigation melanin's interface be conjugated components hybrid nanostructures are critically analyzed. The key remaining challenges summarized an outlook on future perspectives offered. act roadmap guide both newcomers experts who interested learning about immense potential versatile, high‐performance platforms nanotechnology‐driven innovations theranostic nanomedicine.

Language: Английский

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