Hybrid structures of polycationic aluminum phthalocyanines and quantum dots

Maksimov, Eugene G.; Gvozdev, D.A.; Strakhovskaya, M. G.; Paschenko, V.Z.

doi:10.1134/s0006297915030074

Cited by 10 publications

(4 citation statements)

References 44 publications

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“…Although many researchers have prepared conjugates between quantum dots and various different PSs to carry out PDT [101–103], a recent study showed that graphene quantum dots could mediate PDT on their own without any added PS [87]. …”

Section: Nanotechnologymentioning

confidence: 99%

New photosensitizers for photodynamic therapy

Abrahamse

Hamblin

2016

Biochemical Journal

1,600

1,172

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Photodynamic therapy (PDT) was discovered more than 100 years ago, and has since become a well-studied therapy for cancer and various non-malignant diseases including infections. PDT uses photosensitizers (PSs, non-toxic dyes) that are activated by absorption of visible light to initially form the excited singlet state, followed by transition to the long-lived excited triplet state. This triplet state can undergo photochemical reactions in the presence of oxygen to form reactive oxygen species (including singlet oxygen) that can destroy cancer cells, pathogenic microbes and unwanted tissue. The dual-specificity of PDT relies on accumulation of the PS in diseased tissue and also on localized light delivery. Tetrapyrrole structures such as porphyrins, chlorins, bacteriochlorins and phthalocyanines with appropriate functionalization have been widely investigated in PDT, and several compounds have received clinical approval. Other molecular structures including the synthetic dyes classes as phenothiazinium, squaraine and BODIPY (boron-dipyrromethene), transition metal complexes, and natural products such as hypericin, riboflavin and curcumin have been investigated. Targeted PDT uses PSs conjugated to antibodies, peptides, proteins and other ligands with specific cellular receptors. Nanotechnology has made a significant contribution to PDT, giving rise to approaches such as nanoparticle delivery, fullerene-based PSs, titania photocatalysis, and the use of upconverting nanoparticles to increase light penetration into tissue. Future directions include photochemical internalization, genetically encoded protein PSs, theranostics, two-photon absorption PDT, and sonodynamic therapy using ultrasound.

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Section: Nanotechnologymentioning

confidence: 99%

New photosensitizers for photodynamic therapy

Abrahamse

Hamblin

2016

Biochemical Journal

1,600

1,172

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“…The ability of COCP to quench 1 O 2 was tested by illumination of common 1 O 2 sensitizers, either tetra-and pentakis(cholinile) aluminium phthalocyanines (AlPCs) (31) or Rose Bengal (as used in previous 1 O 2 quenching assays (5, 10)), using Singlet Oxygen Sensor Green (SOSG) fluorescence to monitor 1 O 2 generation. Both, COCP and OCP caused a profound reduction of O 2 yield (Supplementary Figure S6).…”

Section: Functional Properties Of Cocpmentioning

confidence: 99%

Assembly of photoactive orange carotenoid protein from its domains unravels a carotenoid shuttle mechanism

et al. 2017

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The photoswitchable orange carotenoid protein (OCP) is indispensable for cyanobacterial photoprotection by quenching phycobilisome fluorescence upon photoconversion from the orange OCP to the red OCP form. Cyanobacterial genomes frequently harbor, besides genes for orange carotenoid proteins (OCPs), several genes encoding homologs of OCP's N- or C-terminal domains (NTD, CTD). Unlike the well-studied NTD homologs, called Red Carotenoid Proteins (RCPs), the role of CTD homologs remains elusive. We show how OCP can be reassembled from its functional domains. Expression of Synechocystis OCP-CTD in carotenoid-producing Escherichia coli yielded violet-colored proteins, which, upon mixing with the RCP-apoprotein, produced an orange-like photoswitchable form that further photoconverted into a species that quenches phycobilisome fluorescence and is spectroscopically indistinguishable from RCP, thus demonstrating a unique carotenoid shuttle mechanism. Spontaneous carotenoid transfer also occurs between canthaxanthin-coordinating OCP-CTD and the OCP apoprotein resulting in formation of photoactive OCP. The OCP-CTD itself is a novel, dimeric carotenoid-binding protein, which can coordinate canthaxanthin and zeaxanthin, effectively quenches singlet oxygen and interacts with the Fluorescence Recovery Protein. These findings assign physiological roles to the multitude of CTD homologs in cyanobacteria and explain the evolutionary process of OCP formation.

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“…In this case, the PS-NP conjugate must be created on the basis of non-covalent interactions [5,6]. Second, the NP can be given additional functionality; for example, it can be used as a lightharvesting antenna that enhances the absorption capacity of the PS in the visible [7,8] or IR region [9,10] of the spectrum. Thus, the PS will mediate photodynamic reactions when combined with NPs and, therefore, the PS-NP complex should be stable.…”

Section: Introductionmentioning

confidence: 99%

Fluorescence Quenching of Carboxy-Substituted Phthalocyanines Conjugated with Nanoparticles under High Stoichiometric Ratios

et al. 2022

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Background: The search of the approaches towards a photosensitizer’s conjugation with multifunctional nanoparticles is an important step in the development of photodynamic therapy techniques. Association of photosensitizer molecules with nanoparticles that perform the delivery function can lead to a change in the functional state of the photosensitizer. Methods: We studied the effects observed upon incorporation of octa- and hexadeca-carboxyphthalocyanines of zinc(II) and aluminum(III) (Pcs) into the polymer shell of nanoparticles with a semiconductor CdSe/CdS/ZnS core with various spectral and optical methods. Results: First, the interaction of Pc with the polymer shell leads to a change in the spectral properties of Pc; the effect strongly depends on the structure of the Pc molecule (number of carboxyl groups as well as the nature of the central cation in the macrocycle). Secondly, upon incorporation of several Pc molecules, concentration effects become significant, leading to Pc aggregation and/or nonradiative energy transfer between neighboring Pc molecules within a single nanoparticle. Conclusions: These processes lead to the decrease of a number of the Pc molecules in an excited state. Such effects should be taken into account during the development of multifunctional platforms for the delivery of photosensitizers, including the use of nanoparticles as enhancers of photosensitizer activity by energy transfer.

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Hybrid structures of polycationic aluminum phthalocyanines and quantum dots

Cited by 10 publications

References 44 publications

New photosensitizers for photodynamic therapy

New photosensitizers for photodynamic therapy

Assembly of photoactive orange carotenoid protein from its domains unravels a carotenoid shuttle mechanism

Fluorescence Quenching of Carboxy-Substituted Phthalocyanines Conjugated with Nanoparticles under High Stoichiometric Ratios

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