Hybrid Complexes of Photosensitizers with Luminescent Nanoparticles: Design of the Structure

Increasing the efficiency of the photodynamic action of the dyes used in photodynamic therapy is crucial in the field of modern biomedicine. There are two main approaches used to increase the efficiency of photosensitizers. The first one is targeted delivery to the object of photodynamic action, while the second one is increasing the absorption capacity of the molecule. Both approaches can be implemented by producing dyenanoparticle conjugates. In this review, we focus on the features of the latter approach, when nanoparticles act as a light-harvesting agent and nonradiatively transfer the electronic excitation energy to a photosensitizer molecule. We will consider the hybrid photosensitizerquantum dot complexes with energy transfer occurring according to the inductive-resonance mechanism as an example. The principle consisting in optimizing the design of hybrid complexes is proposed after an analysis of the published data; the parameters affecting the efficiency of energy transfer and the generation of reactive oxygen species in such systems are described.

Novel chlorophyll a derivatives with ester-linked galactose fragments for photodynamic therapy and fluorescence diagnostics of cancer

In the present work, a number of chlorophyll [Formula: see text] derivatives were synthetized with galactose fragments with an ester bond between macrocycle and carbohydrate fragments. It showed that synthesized compounds fluoresce intensely inside HeLa cells, which enable these compounds to be considered as potential diagnostic agents and indicates their ability to remain in the cell in an unassociated photoactive state — a necessary condition for the realization of a photodynamic action. It was determined that while all conjugates had comparable photoinduced toxicities, the conjugate with phorbin macrocycle fragment had a much lower dark toxicity, which corresponds to the trends noted earlier. In terms of a therapeutic window, conjugate significantly exceeds similar derivatives of chlorin [Formula: see text] and is the most promising for further research.