Drug Delivery Systems for Phthalocyanines for Photodynamic Therapy

Abstract

The focus of this review is to describe the state-ofart in the development of innovative drug delivery systems for phthalocyanines as photosensitizers for photodynamic therapy (PDT). PDT is a medical treatment combining photosensitizers (PSs) activated by visible light of a specific wavelength to selectively destroy targeted cells, tumor tissues and its surrounding vasculature. In the last decades, PDT has been under intense investigation, first as a promising alternative approach for improved cancer treatment, later against microbial infection and nowadays, mainly in aesthetic medicine, against age-related degeneration. The success of PDT is restricted because of difficulties with administration and skin permeation of PSs. As PDT importance raises, there is high interest for advanced formulations and delivery systems (DDS) for PS, especially formulations based on nanotechnology. Accordingly, this review deals with the innovations pertaining to DDS for PDT as disclosed in recent patents and literature.

Encapsulation for Cancer Therapy

“…Thus, the obtained biodegradable and biocompatible dendrimers increase aqueous solubility of the derived camptothecin drugs and improve both the uptake and retention of camptothecins within cancer cells (Figure 6a and 6b). Figure 6c shows the chemical structure of zinc phthalocyanine, which is used for tumor targeting and treatment [49][50][51]. The covalent conjugation of zinc phthalocyanine with a dendrimeric structure results in a controlled drug delivery system that could be photochemically activated [52].…”

Polymers for enhanced photodynamic cancer therapy: Phthalocyanines as a photosensitzer model

“… 48 After incubation of the NCs to osteosarcoma cells and irradiation with a far‐red light 100‐fold cytotoxicity, compared to the free PS. The cell death mechanism was suggested to include mitochondrial injury and promotion of cell cycle arrest at G2/M 49 . In‐vivo experiments on osteosarcoma bearing mice showed the good bio distribution profile and high phototoxicity of the prepared formulations.…”

A Translational Study of a Silicon Phthalocyanine Substituted with a Histone Deacetylase Inhibitor for Photodynamic Therapy

“… 6 , 7 Over the years, PDT has gained extensive attention and became a treatment option for both oncological and non-oncological medical conditions, thanks to its specificity and selectivity since PS tend to accumulate in rapidly dividing and diseased tissues while cytotoxic effect of the drug is limited to the irradiation area. 8 PDT can be used to treat tumors that cannot be surgically resected and, unlike invasive and systemic treatment options, offers long-term management of the tumor even though sometimes the treatment cannot cure the disease. 6 A group of second-generation PSs, phthalocyanines (Pcs), are stable synthetic macromolecules that can absorb light at a long-wavelength efficiently and generate high levels of ROS.…”