The Photocatalytic Properties of Peptide- and Protein-Capped Inorganic Semiconductor Nanocrystals

Información del proyecto

Identificador del acuerdo de subvención: INTAS-2000-00554

Proyecto cerrado

Fecha de inicio 1 Julio 2001

Fecha de finalización 30 Junio 2004

Financiado con arreglo a

• International Association for the promotion of cooperation with scientists from the independent states of the former Soviet Union (INTAS), 1993-

Coste total

Sin datos

Aportación de la UE

€ 150 000,00

Coordinado por

Swiss Federal Institute of Technology of Lausanne
Switzerland

Objetivo

In recent years photodynamic therapy (PDT) has been extensively developed in various countries for treatment of certain types of cancer and skin diseases. PDT is based on the use of natural or synthetic photosensitizers, which, because of their specific chemical structure, are capable of accumulating in cancerous tissues. In the clinical therapy of cancer some drugs based on hematoporphyrin-IX, are used as photosensitizers. There are, however, some problems associated in their use, such as prolonged cutaneous phototoxicity, photodegradation during illumination and weak absorption of light in the region of the highest tissue transparency. These limitations have prompted a search for alternative PDT photosensitizers.
The present inter-disciplinary project focuses on inorganic semiconductor nanocrystals (SNs) as potential photosensitizers for PDT of various cancerous and skin diseases. Semiconductor nanocrystals, whose particle size is comparable to that of organic dye molecules, are capable, just as bulk semiconductors, to produce electrons and holes in the conduction and valence bands upon bandgap illumination. These charge carriers have been demonstrated to be very active towards oxidizable and reducible substrates. In addition, semiconductor nanocrystals are likely to be more active and stable than organic photosensitizers.
We intend to use different peptides, proteins and ferritin as templates and capped agents for CdS, CdSe, FeS2, InAs, InP, Fe203 and other semiconductor nanocrystals synthesis. These peptide- or protein-capped SNs, absorbing light in a wide spectral range (up to lambda = 900 nm), would be able to photosensitize various destruction processes in the cells. In addition, peptide- and protein-capped Fe203 SNs and complexes of the iron-storage protein ferritin with SNs under the action of light are a viable source of Fe2+ ions which is capable of initiating chain oxidation processes and more generally to participate in catalytic oxidation processes in oxygenated media.

The main objectives of the project are:
1) to obtain peptide and protein-capped nanocrystals of inorganic semiconductors absorbing light in the tissue transparency region (e.g. lambda = 600-900 nm);
2) to investigate the mechanisms and dynamics of photoinduced electron transfer processes occurring between SNs complexes and species in aqueous solution;
3) to study the photocatalytic properties of peptide- or protein-capped SNs;
4) to determine the conditions of the photodissolution of ferric oxide/hydroxide nanocrystals capped with peptides and proteins and of ferric hydroxide nanocrystals found in the interior of ferritin with their concomitant production of Fe2+ ions;
5) to study the processes of destruction of biomolecules, cells and subcellular structures upon photosensitization by peptide- and protein-capped SNs;
6) to elucidate the chemical mechanism of the destruction processes sensitisation under laser pulse excitation; and finally,
7) to study the photosensitizing action of peptide- and protein-capped SNs on different types of human tumor cell lines; to provide the specific delivery of SNs to tumor cells using conjugates of SNs with antiferritin antibodies and biotinylated antibodies with avidin.

The studies of the processes of destruction of biomolecules, subcellular structures and tumor cells photosensitized by will allow knowledgeable recommendations for the use of this type of sensitizer in cancer treatment. Obtained results will also be of a very broad interest in physical chemistry and biology as they will contribute to the understanding of the mechanisms and dynamics of electron transfer processes taking place in artificial and biological systems containing inorganic semiconductors and proteins.

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Programa(s)

• IC-INTAS - International Association for the promotion of cooperation with scientists from the independent states of the former Soviet Union (INTAS), 1993-

Tema(s)

• 3 - Chemistry
• OPEN - OPEN Call

Convocatoria de propuestas

Datos no disponibles

Régimen de financiación

Datos no disponibles

Coordinador

Swiss Federal Institute of Technology of Lausanne

• Aportación de la UE: Sin datos
• Dirección: EPFL - DC ; 1015 Lausanne ; Suiza
• Coste total: Sin datos

Participantes (6)

Belarussian National Academy of Sciences

Bielorrusia

• Aportación de la UE: Sin datos
• Dirección: Zhodinskaya ; 220141 Minsk
• Coste total: Sin datos

Cardiology Research Center

Rusia

• Aportación de la UE: Sin datos
• Dirección: 3rd Cherepkovskaya St. 15a ; 121552 Moscow
• Coste total: Sin datos

Chemical Physics Research Institute

Rusia

• Aportación de la UE: Sin datos
• Dirección: 142432 Chernogolovka, Moscow district
• Coste total: Sin datos

M.V. Lomonosov Moscow State University

Rusia

• Aportación de la UE: Sin datos
• Dirección: Vorobjevi Gori ; 117234 Moscow
• Coste total: Sin datos

Russian Academy of Sciences

Rusia

• Aportación de la UE: Sin datos
• Dirección: Leninskii pr. ; 117071 Moscow
• Coste total: Sin datos

UNIVERSITY OF BRISTOL

Reino Unido

• Aportación de la UE: Sin datos
• Dirección: CANTOCK'S CLOSE ; BS8 1TS BRISTOL
• Coste total: Sin datos