scholarly journals New Approach in the Application of Conjugated Polymers: The Light-Activated Source of Versatile Singlet Oxygen Molecule

Materials ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1098
Author(s):  
Agata Blacha-Grzechnik

For many years, the research on conjugated polymers (CPs) has been mainly focused on their application in organic electronics. Recent works, however, show that due to the unique optical and photophysical properties of CPs, such as high absorption in UV–Vis or even near-infrared (NIR) region and efficient intra-/intermolecular energy transfer, which can be relatively easily optimized, CPs can be considered as an effective light-activated source of versatile and highly reactive singlet oxygen for medical or catalytic use. The aim of this short review is to present the novel possibilities that lie dormant in those exceptional polymers with the extended system of π-conjugated bonds.

2002 ◽  
Vol 106 (35) ◽  
pp. 9019-9026 ◽  
Author(s):  
Sergei Lebedkin ◽  
Timo Langetepe ◽  
Paloma Sevillano ◽  
Dieter Fenske ◽  
Manfred M. Kappes

2013 ◽  
Vol 2 (3) ◽  
Author(s):  
Andrey V. Ivanov ◽  
Valentina D. Rumyantseva ◽  
Igor P. Shilov ◽  
Valerii M. Markushev ◽  
Andrey I. Panas ◽  
...  

Abstract:This article deals with the creation of new low-toxic photosensitizers on the basis of Ytterbium-2,4-dimethoxyhematoporphyrin IX (Yb-DMHP) and their application for the luminescence diagnostics of cancer. These substances were found to weakly generate singlet oxygen, exhibit pronounced luminescence, and retain the tumor-tropic properties of therapeutic photosensitizers. Basic photophysical properties of Yb-DMHP were studied, and the primary toxicological and pharmacokinetic investigations were performed in the organisms of experimental animals. The 4f-luminescence of Yb-DMHP in the near infrared (NIR) spectral region was observed. Comparative investigations were performed for one of the photodynamic medications which have been approved for clinical application: “Photoditazin”, a diglucosamine salt of chlorin e6. It was shown that the efficiency of singlet oxygen generation is lower by approximately one order of magnitude in the case of Yb-DMHP. The experimental data prove that Yb-DMHP-based substances are promising as non-toxic markers for the luminescence diagnostics of malignant tumors in the NIR spectral range (900–1100 nm), because they are free of the phototoxicity that is typical of conventional porphyrins, while at the same time providing a relatively high luminescence contrast and a selective accumulation in tumor tissue.


2019 ◽  
Author(s):  
Arundhati Deshmukh ◽  
Danielle Koppel ◽  
Chern Chuang ◽  
Danielle Cadena ◽  
Jianshu Cao ◽  
...  

Technologies which utilize near-infrared (700 – 1000 nm) and short-wave infrared (1000 – 2000 nm) electromagnetic radiation have applications in deep-tissue imaging, telecommunications and satellite telemetry due to low scattering and decreased background signal in this spectral region. However, there are few molecular species, which absorb efficiently beyond 1000 nm. Transition dipole moment coupling (e.g. J-aggregation) allows for redshifted excitonic states and provides a pathway to highly absorptive electronic states in the infrared. We present aggregates of two cyanine dyes whose absorption peaks redshift dramatically upon aggregation in water from ~ 800 nm to 1000 nm and 1050 nm with sheet-like morphologies and high molar absorptivities (e ~ 10<sup>5 </sup>M<sup>-1</sup>cm<sup>-1</sup>). To describe this phenomenology, we extend Kasha’s model for J- and H-aggregation to describe the excitonic states of <i> 2-dimensional aggregates</i> whose slip is controlled by steric hindrance in the assembled structure. A consequence of the increased dimensionality is the phenomenon of an <i>intermediate </i>“I-aggregate”, one which redshifts yet displays spectral signatures of band-edge dark states akin to an H-aggregate. We distinguish between H-, I- and J-aggregates by showing the relative position of the bright (absorptive) state within the density of states using temperature dependent spectroscopy. Our results can be used to better design chromophores with predictable and tunable aggregation with new photophysical properties.


2019 ◽  
Vol 21 (1) ◽  
pp. 21-25 ◽  

Emerging results support the concept that Alzheimer disease (AD) and age-related dementia are affected by the ability of the immune system to contain the brain's pathology. Accordingly, well-controlled boosting, rather than suppression of systemic immunity, has been suggested as a new approach to modify disease pathology without directly targeting any of the brain's disease hallmarks. Here, we provide a short review of the mechanisms orchestrating the cross-talk between the brain and the immune system. We then discuss how immune checkpoint blockade directed against the PD-1/PD-L1 pathways could be developed as an immunotherapeutic approach to combat this disease using a regimen that will address the needs to combat AD.


2019 ◽  
Vol 21 (1) ◽  
pp. 21-25 ◽  

Emerging results support the concept that Alzheimer disease (AD) and age-related dementia are affected by the ability of the immune system to contain the brain’s pathology. Accordingly, well-controlled boosting, rather than suppression of systemic immunity, has been suggested as a new approach to modify disease pathology without directly targeting any of the brain’s disease hallmarks. Here, we provide a short review of the mechanisms orchestrating the cross-talk between the brain and the immune system. We then discuss how immune checkpoint blockade directed against the PD-1/PD-L1 pathways could be developed as an immunotherapeutic approach to combat this disease using a regimen that will address the needs to combat AD.


2021 ◽  
Vol 23 (12) ◽  
pp. 7495-7503
Author(s):  
Wanlin Cai ◽  
Kai Ren ◽  
Ancong Zhao ◽  
Xiulan Wu ◽  
Rongxing He ◽  
...  

Compared to the PtOO7-based system, the greater EQE of the PtON7-based system is mainly governed by the stronger energy transfer efficiency (ηEET); thus, it is necessary to evaluate ηEET from hosts to guests for the rational design of OLEDs.


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