Page 32 - ITPS-8-2

INNOSC Theranostics and
Pharmacological Sciences The biochemical and biophysical guide for photodynamic therapy

Table 2. The most commonly used photosensitizers in photodynamic therapy
Photosensitizer Generic name Wavelength (nm) Application
Porphyrins Photofrin, 5-aminolevulinic acid 600 – 700 Skin (superficial), head and neck, internal tumors (sometimes)
Chlorophyllins Verteporfin 690 Eye diseases, mainly macular degeneration
Phthalocyanines Chlorine aluminum sulfonate 650 – 800 Surface and internal
Bacterioporphyrins Fotoditazin 600 – 700 Bacterial skin infections
Hematoporphyrin Tookad 763 Prostate cancer

derivatives are synthesized by reacting 2,2’-dipyrromethene in the development of BODIPY compounds is improving
derivatives with boron trifluoride-diethyl ether complex their solubility in water and physiological media while
(BF (C H ) O) in the presence of triethylamine or preventing the formation of non-fluorescent aggregates.
2
5 2
3
1,8-diazabicyclo5.4.0]undec-7-ene. Recent advancements One promising approach is the incorporation of
have led to the design and synthesis of BODIPY-based hydrophilic fragments, such as polyethylene glycol (PEG),
platinum complexes for PDT, where the introduction of N,N-bis(2-hydroxyethyl)amine, sugars, nucleotides, or
platinum atoms has been shown to improve both solubility ionic groups (carboxylic, sulfuric, and ammonium acids)
1
and O quantum yield. BODIPY-hetero[5]helicene into the BODIPY structure, which enhances their solubility
31
2
compounds, which combine the structures of BODIPY in water and prevents aggregation. The integration of PEG
and hetero [5]helicene, have also been synthesized. These into drugs improves their solubility in water, facilitates
compounds exhibit excellent optical properties and high cellular uptake, and increases the overall therapeutic
ISC efficiency, with ISC efficiency correlating to the efficacy. 34
torsion angles of the compounds. Studies have explored The amphipathic polymer PS PEG-BODIPY was
their potential as PDT agents, and one BODIPY-hetero[5] developed as a carrier for DDS with real-time tracking
helicene compound was found to effectively kill cancer properties. Composed of a hydrophilic PEG segment
cells upon light exposure. The anticancer efficacy of this and a hydrophobic BODIPY segment, PEG-BODIPY
compound was verified using clonogenic and MTT assays, enables the encapsulation of anticancer drugs, such as
showing that they can effectively target and kill cancer doxorubicin (DOX), into micelle spaces. These micelles
cells from various tissue origins, including U2-OS, MCF- spontaneously self-assemble in aqueous environments
7, and MDA-MB-231 cell lines after photo exposure [B]. into bilayer amphiphilic polyethylene glycol-grafted
PDT using aza-BODIPY has also been shown to induce (PEGylated) BODIPY polymers. A cellular uptake study
apoptosis in MCF-7 breast cancer cells by activating p53
and caspase 3. Flow cytometry analysis revealed that 28% of PEGylated BODIPY and DOX@PEGylated BODIPY
of the cells underwent apoptosis. Gene expression analysis nanoformulations showed that MDA-MB-231 cells
endocytosed these nanoformulations within 24 h. The
35
post-PDT exhibited downregulation of epidermal growth fluorescence intensity of PEGylated BODIPY significantly
factor, lymphoid enhancer-binding factor 1, WNT family increased with the concentration of nanoformulations, and
member 1, transcription factor 7, and transforming growth both types of nanoformulations were primarily localized in
factor beta receptor II genes, alongside upregulation of lysosomes.
caspase 3 and tumor protein P53. PDT also impairs cell
connectivity and affects the cell cycle. Notably, these The results of studies on the anticancer effects of
effects were not observed in control cells and MCF-7 cells PEGylated BODIPY and DOX@PEGylated BODIPY
under dark field conditions, indicating that aza-BODIPY nanopreparations demonstrated high phototoxicity
possesses potent antitumor photodynamic activity. 32,33 and low toxicity in dark conditions. Upon irradiation,
36
Boron-dipyrromethene compounds are widely utilized PEGylated BODIPYs exhibited cytotoxicity with an
@
in various fields, particularly in biomedicine and technology. IC50 of approximately 25 nM, whereas DOX PEGylated
In biomedicine, BODIPYs are used as fluorescent probes for BODIPYs showed even stronger phototoxicity, with
1
bioimaging and as O generators in PDT. They also serve as an IC50 of around 10 nM. The higher IC50 for DOX@
2
fluorescent sensors, bioconjugate components, laser dyes, PEGylated BODIPY can be attributed to the combination
of BODIPY-mediated PDT and DOX chemotherapy.
and switches. In technology, BODIPYs are applied in solar
@
fuel generation, photovoltaic devices, antenna systems, In DOX PEGylated BODIPY nanopreparations,
photoredox catalysis, photooxidation of organic pollutants, BODIPY compounds generate O during light irradiation,
1
2
and the photoinitiation of polymerization. A key challenge not only inducing phototoxicity in cancer cells but also
Volume 8 Issue 2 (2025) 26 doi: 10.36922/itps.4559