H2020Индивидуална стипендия2019–2021

Mel.Photo.Protect · Unraveling the Photoprotecting Mechanism of Melanin - From a Library of Fragments to Simulation of Spectra and Function

„Хоризонт 2020“ — Действия „Мария Склодовска-Кюри“

Период: 2019-09-01 → 2021-08-31
Финансиране от ЕС: 172 932 €
Участници: 1
Схема: MSCA-IF-EF-ST

Линиите свързват координатора с партньорите.

Накратко на български

Меланинът и неговата сложна структура се анализират, за да се разбере как точно той абсорбира светлината и предпазва организма. Тези знания помагат при създаването на нови функционални материали и при изясняването на механизмите на някои заболявания.

Този кратък обзор е генериран от изкуствен интелект

Кратко обяснение, генерирано от езиков модел по текста на CORDIS. Оригиналът е по-долу.

Резултати накратко

Unraveling the Photoprotecting Mechanism of Melanin - From a Library of Fragments to Simulation of Spectra and Function

In our research programme we aim to provide a new view on the photoprotecting function of melanin based on systematic consideration of its disordered, heterogeneous structure. In particular, we want to answer the following pressing questions related with the photoprotecting function: (1) What specific structural elements are responsible for the broad absorption? What are the absorption properties of the aggregates? How do they depend on the number of units, connectivity and redox state of the oligomers? What is the difference between DHI and DHICA-based aggregates? How are the spectral characteristics of the oligomers tuned in the aggregate environment? How do they depend on aggregate size? (2) What is/are the photoprotection mechanism(s)? Are all aggregates equally capable of dissipating the excitation energy, or is there a particular aggregate type responsible for this function? Is there more than one dissipation mechanism? (3) Why do disaggregation and/or oxidation reduce the photoprotecting efficiency? Is this related to chemiexcitation? To answer these questions, we will simulate the photophysical properties of the different aggregates using state-of-the-art theoretical methods, and we will obtain structure-property relationships telling the us the absorption properties and preferred decay mechanism of the different aggregates. The detailed understanding of the photoprotecting function that we want to deliver will provide new principles for the design of PDA-based functional materials and will help us to assess the possible pathogenic role of melanin chemiexcitation. Starting from the widely accepted structural model of melanin as a heterogeneous material, our proposal is based on the following hypotheses: • Oligomer aggregation plays a crucial role in the photophysics and has to be accounted for in realistic models • Melanin photophysical properties do not stem from a particular aggregate but result from different aggregates that may have similar or complementary properties • A systematic approach covering structural, redox and geometrical diversity is essential for a full understanding of melanin photoprotecting function Based on these ideas, the specific objectives are: • O1. Construct a library of DHI and DHICA based aggregates with structural, redox and geometrical diversity • O2. Simulate the absorption spectra of the aggregates and establish a structure-property relationship • O3. Simulate the decay mechanisms for different aggregates

Текст от CORDIS, на английски · Данни: CORDIS, © Европейски съюз

Цел на проекта

Melanin is the deeply coloured, insoluble and heterogenous biopolymer of animal skin, hair and eyes responsible for protection against harmful light action. It also has a pathogenic role as a generator of reactive oxygen species and possibly through chemiexcitation, and its polydopamine synthetic analogue has raised great interest in the materials community. In spite of these multiple points of interest, the details of melanin structure and its main photoprotecting function are still largely unknown, mostly due to the heterogeneous polymer structure. Closing this gap is an urgent challenge, and our proposal aims at doing that with the methods of computational chemistry. Based on the widely accepted hierarchical structure model for melanin, in WP1 we will generate a library of aggregates made of 5,6-dihydroxyindole (DHI) and 5,6-dihydroxyindole-2-carboxylic acid (DHICA) oligomers with different connectivity and redox state (diol, semiquinone and quinone forms). In WP2 we will simulate the absorption spectra of the aggregates and compare them with the experimental melanin spectrum, which starts at the near IR and increases monotonically into the UV. In WP3 we will simulate the excited-state decay mechanisms for the different aggregates in order to explain melanin's lack of fluorescence, which is indicative of fast decay responsible for its photoprotecting function. The results of our project will provide a new view on the photoprotecting function of melanin based on a systematic consideration of its heterogeneous structure, and they will allow us to assess what specific aggregates are responsible for the different functional characteristics. They will help us to assess the possible pathogenic role of melanin chemiexcitation, and provide new principles for design of PDA-based functional materials.

Оригинален текст от CORDIS (на английски).

Участници

UNIVERSITAT DE GIRONA · GironaКоординаторИспания