Density functionalized [Ru^II(NO)(Salen)(Cl)] complex: Computational photodynamics and in vitro anticancer facets.

Area of Science:

• Inorganic Chemistry
• Computational Chemistry
• Photochemistry

Background:

• Photodynamic therapy (PDT) offers a promising avenue for cancer treatment, necessitating the development of efficient photosensitizing agents.
• Ruthenium complexes are being investigated for their therapeutic potential, particularly in cancer therapy.
• The N, N'-salicyldehyde-ethylenediimine (Salen) ligand system provides a versatile scaffold for metal complex design.

Purpose of the Study:

• To computationally investigate the photodynamic behavior of a ruthenium(II) nitrosyl complex with a Salen ligand.
• To evaluate the in vitro anticancer activity and nitric oxide releasing capabilities of the synthesized ruthenium complex.
• To compare the efficacy of the target complex with known photosensitizers and related ruthenium compounds.

Main Methods:

• Density Functional Theory (DFT) calculations using B3LYP functional with LanL2DZ and 6-31G(d,p) basis sets were performed to study ground and excited states.
• In vitro antiproliferative assays were conducted against COLO-205 human cancer cells.
• Comparative analysis with phthalocyanine, porphyrin derivatives, and [RuCl3(PPh3)3] was performed.

Main Results:

• DFT calculations elucidated the electronic structure and photophysical properties of the ruthenium-Salen complex.
• The complex demonstrated effective photoactivity attributed to the ruthenium core.
• In vitro studies revealed significant antiproliferative effects, with the target complex exhibiting a lower IC50 value (9.74 mg/mL) compared to [RuCl3(PPh3)3] (40.031 mg/mL).
• Visible light-triggered nitric oxide release was inferred, highlighting its potential in targeted cancer therapy.

Conclusions:

• The ruthenium-Salen complex shows promise as an anticancer agent due to its photodynamic properties and nitric oxide releasing capability.
• The combination of DFT-guided design and experimental validation supports its candidacy for both chemotherapy and light-activated therapy.
• The study underscores the importance of ruthenium complexes in developing novel therapeutic strategies for cancer treatment.