Abstract

Fluorescent nanoparticles are currently considered as promising enhancers of photodynamic activity of traditional photosensitizers in procedures for photodynamic therapy of cancer and inactivation of pathogens. On the one hand, such nanoparticles act as a nanoplatform for target delivery of dye molecules to cells; on the other hand, they act as light-harvesting antennas that increase the effective absorption cross-section of the dye. This paper investigates the effect of semiconductor CdSe/ZnS quantum dots coated with a polymer shell on the photostability of zinc or aluminum polycationic phthalocyanines. It was shown that the rate of photobleaching of phthalocyanines increases significantly in the presence of quantum dots both under direct illumination of phthalocyanine by red light and under the quantum dot-mediated illumination by blue light. This effect can be explained by the fact that phthalocyanine inside the polymer shell of the quantum dot is the primary target for the attack by reactive oxygen species. The rate of bleaching of the chemical trap of reactive oxygen species, 4-nitroso-N,N-dimethylaniline, in a phthalocyanine solution increases in the presence of the quantum dot under red light illumination. We believe that the chemical trap is concentrated in the polymer shell of the quantum dot, which increases the probability of its damage by active oxygen species generated by phthalocyanine. Since the diffusion of reactive oxygen species from the polymer shell of the nanoparticle into the surrounding solution is slow, the use of quantum dots as an enhancer of the photodynamic action of phthalocyanines can be effective only in the absence of significant steric obstacles to the diffusion of reactive oxygen species to the target molecules of photodynamic inactivation.

中文翻译：

---

酞菁分子与胶体量子点复合物中的光漂白。

摘要

荧光纳米颗粒目前被认为是在癌症的光动力治疗和病原体灭活过程中传统光敏剂的光动力活性的有希望的增强剂。一方面，此类纳米颗粒充当纳米平台，用于将染料分子靶向递送至细胞；另一方面，它们充当光收集天线，可增加染料的有效吸收截面。本文研究了涂有聚合物壳的半导体CdSe / ZnS量子点对锌或铝聚阳离子酞菁的光稳定性的影响。结果表明，在存在量子点的情况下，在酞菁被红光直接照射下和在量子点介导的蓝光照射下，酞菁的光漂白速率均显着增加。可以通过以下事实来解释这种效果：量子点的聚合物壳内部的酞菁是活性氧攻击的主要目标。在红光照射下，在存在量子点的情况下，酞菁溶液中的活性氧物种4-亚硝基-N，N-二甲基苯胺的化学陷阱的漂白速率增加。我们认为化学陷阱集中在量子点的聚合物壳中，这增加了酞菁产生的活性氧对它的破坏的可能性。由于活性氧从纳米颗粒的聚合物壳扩散到周围溶液中的速度很慢，