Relocation of a biological photosensitizer from non-ionic micellar carrier to DNA: A multispectroscopic investigation

Relocation of a bioactive photosensitizer, namely phenosafranin (PSF), from the phenazinium family, has been demonstrated from non-ionic micellar carrier to the DNA. For the purpose, interaction of micelle-bound PSF with calf thymus DNA (ctDNA) has been investigated vividly exploiting various spectroscopic techniques like absorption, steady state and time resolved emission, fluorescence anisotropy, circular dichroism etc. Experimental outcomes reveal that PSF binds strongly with both the micelle as well as the DNA. In the presence of DNA, however, relocation of the micelle-carried PSF occurs from the micelle to the DNA. Competitive binding of the probe between micelle and the DNA is assigned responsible for this relocation. Circular dichroism spectral measurements reflect that the DNA conformation remains intact in the presence of the micelle advocating that the non-ionic micelles can safely be used for the drug delivery purpose. The work is expected to encourage development of newer carriers for DNA targeted drug delivery.