Biotin and boron-dipyrromethene-tagged platinum(IV) prodrug for cellular imaging and mito-targeted photocytotoxicity in red light.
Arpan BeraAmrita NepaliaAarti UpadhyayDeepak Kumar SainiAkhil R ChakravartyPublished in: Dalton transactions (Cambridge, England : 2003) (2023)
A platinum(IV) prodrug, cis , cis , trans -[Pt(NH 3 ) 2 Cl 2 (biotin)(L)] (1), derived from cisplatin, where HL is the PEGylated red-light active boron-dipyrromethene (BODIPY) ligand, was synthesized, characterized and its photocytotoxicity evaluated. The complex showed a near-IR absorption band at 653 nm ( ε ∼9.19 × 10 4 M -1 cm -1 ) in dimethyl sulfoxide and Dulbecco's phosphate-buffered saline (1 : 1 v/v) at pH 7.2. When excited at 630 nm, it showed an emission band at 677 nm in DMSO with a fluorescence quantum yield of 0.13. The 1,3-diphenylisobenzofuran titration experiment gave a singlet oxygen quantum yield ( Φ Δ ) of ∼0.32. A mechanistic DNA photocleavage study revealed singlet oxygen as the reactive oxygen species (ROS). The complex with biotin and PEGylated-distyryl-BODIPY showed significantly higher cellular uptake in A549 cancer cells as compared to non-cancerous Beas-2B cells from flow cytometry, indicating selectivity towards cancer cells. A dichlorodihydrofluorescein diacetate assay showed cellular ROS generation. Confocal images revealed predominant internalization in the mitochondria. The prodrug showed remarkable photodynamic therapy (PDT) activity in cancerous A549 and multidrug-resistant MDA-MB-231 cells with a high photocytotoxicity index value (half-maximal inhibitory concentration (IC 50 ): 0.61-1.54 μM in red light), while being non-toxic in the dark. The chemo-PDT activity was significantly less in non-tumorigenic lung epithelial cells (Beas-2B). The prodrug effectively triggered cellular apoptosis, which was confirmed by the Annexin V-FITC/propidium iodide assay, and the alteration of the mitochondrial membrane potential was substantiated by the JC-1 dye assay. The β-tubulin immunofluorescence assay confirmed that incubating the cells with a light-treated complex resulted in the rapture of the cytoskeletal structure and the formation of apoptotic bodies. The results demonstrate that the prodrug triggered apoptosis via DNA damage, a reduction in mitochondrial function and disruption of the cytoskeletal framework.
Keyphrases
- photodynamic therapy
- cell cycle arrest
- cell death
- cancer therapy
- reactive oxygen species
- dna damage
- oxidative stress
- fluorescence imaging
- energy transfer
- induced apoptosis
- high throughput
- drug release
- flow cytometry
- pi k akt
- drug delivery
- multidrug resistant
- endoplasmic reticulum stress
- single cell
- molecular dynamics
- high resolution
- single molecule
- living cells
- fluorescent probe
- optical coherence tomography
- deep learning
- squamous cell carcinoma
- cystic fibrosis
- heart rate
- risk assessment
- recombinant human
- mass spectrometry
- newly diagnosed
- highly efficient
- circulating tumor
- raman spectroscopy