Photochromic materials as a photosensitizer in reversible reactive singlet oxygen generation

• Published in: Dyes and pigments Vol. 199; p. 110104
• Main Authors: Gulati, Loveleen Kaur, Gulati, Gurleen Kaur, Kumar, Satish
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.03.2022
• Subjects: Cancer; PDT; Photochromism; Photodynamic therapy; Photosensitizer; Singlet oxygen; PDT; Photodynamic therapy; Singlet oxygen; Photochromism; Photosensitizer; Cancer
• ISSN: 0143-7208; 1873-3743
• DOI: 10.1016/j.dyepig.2022.110104

Photochromism is a well-researched phenomenon that accounts for alteration in the structure, polarity, appearance and other physio-chemical properties of a compound upon light stimulation. It has proved its competence in diverse fields like ophthalmics, data storage, molecular switches, environmental monitoring, superior bioimaging etc. Now to add another feature to its function list, photodynamic therapy (a cancer cure therapy) has been explored in the light of photochromism in this review. In recent years, PDT has become the most desirable subject of research owing to its dire need in the present scenario. Even though several reviews have been published to date, this review has yet a lot novel to offer. On account of the light/heat-responsive structural transformation, photochromic species have been found to play three different roles in advancing the efficacy of PDT– i) photochromes as photosensitizers, ii) as switches to the conventional photosensitizers and iii) as singlet oxygen reserves. Among the wide classes of photochromic molecules, spiropyran, dimethyldihydropyrene (DHP), diarylethene (DAE), azobenzene & anthracene are some that have displayed potential for exploitation as PDT agents in some or the other way. [Display omitted] •Photodynamic therapy has been discussed concerning photochromic photosensitizers.•Photochromic molecules have the potential to act as switchable photosensitizers in PDT.•Photochromic moieties can control photosensitization by conventional photosensitizers.•Photochromes have also exhibited their ability to trap singlet oxygen required to treat hypoxia.