Sensitivity of Papilloma Virus-Associated Cell Lines to Photodynamic Therapy with Curcumin-Loaded Liposomes

• Main Authors: Ghazala Ambreen, Lili Duse, Imran Tariq, Uzma Ali, Sajid Ali, Shashank R. Pinnapireddy, Michael Bette, Udo Bakowsky, Robert Mandic
• Format: Article
• Language: English
• Published: MDPI AG 2020-11-01
• Series: Cancers
• Subjects: head and neck squamous cell carcinoma (HNSCC); head and neck cancer; cervical cancer; photodynamic therapy; curcumin liposomes; papilloma virus
• Online Access: https://www.mdpi.com/2072-6694/12/11/3278

Photodynamic therapy (PDT) is a minimally invasive therapeutic approach used in the treatment of various medical conditions and cancerous diseases, involving light, a photosensitizing substance, and oxygen. Curcumin, a naturally occurring compound, carries antitumor activities and potentially could be exploited as a photosensitizer in PDT. Only little is known about liposomal-encapsulated curcumin that could help in increasing the efficacy, stability, and bioavailability of this compound. This study investigates the in vitro effects of curcumin-loaded liposomes in combination with PDT. Three papilloma virus-associated cell lines were treated with curcumin-loaded liposomes corresponding to a curcumin concentration of 0–100 µmol/L for 4 h followed by illumination at 457 nm (blue) for 45, 136, and 227 s at a fluence of 220.2 W/m² (100 mA) corresponding to 1, 3 and 5 J·cm⁻². After 24 h, the biological outcome of the treatment was assessed with the MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide), SYTO9/PI (propidium iodide), Annexin V-FITC (fluorescein isothiocyanate)/PI, clonogenic survival, and scratch (wound closure) assays. Photoactivation of curcumin-loaded liposomes led to a significant reduction in colony formation and migratory abilities, as well as to an increase in tumor cell death. The results point to the combination of curcumin-loaded liposomes with PDT as a potentially useful tool for the treatment of papillomavirus-associated malignancies.