Jacobs Journal of Nanomedicine and Nanotechnology

Pc 4 Conjugated Iron Oxide Nanoparticles as Photodynamic Therapeutic Carriers

*Michael Giersig
Department Of Experimental Physics, Freie University Berlin, Arnimallee, Germany

*Corresponding Author:
Michael Giersig
Department Of Experimental Physics, Freie University Berlin, Arnimallee, Germany

Published on: 2018-12-22


Magnetite nanoparticles have been chosen in the CosmoPHOS-nano project as one of three types of phthalocyanine conjugated carrier particles because of their magnetic properties and biocompatibility. The main challenge was the dye-conjugation of the nanoparticles. This article does not focus on the magnetic properties but rather on the possibilities of using these conjugates in the Life- Science. Monodisperse magnetite nanoparticles, 15 nm in diameter, were prepared by thermal decomposition of iron(III) oleate in high boiling octadecene in presence of oleic acid as a stabilizer. Ligand exchange of oleic acid by aspartic acid enables water solubility. Next, amino groups were present at the outer nanoparticle’s surface which allows for further attachment of the phthalocyanine Pc 4 by standard conjugation techniques. Pc 4 producing singlet oxygen through illumination at 670 nm in water was investigated as a photosensitizer. Further photodynamic cell-killing experiments with these dye-conjugated carriers on mouse macrophage cell lines showed high efficacy with IC50-values down to 0.03 ng/µl Pc 4, i.e. 1.9 ng/µl Fe3 O4 .


Photodynamic Therapy; Magnetite Nanoparticles; Pc 4; Cell-Killing


Photodynamic therapy (PDT) is getting more and more popular because of its low invasiveness and low toxicity. It is used in treatment of e.g. acne, malignant cancer or arteriosclerosis by inducing cell apoptosis or necrosis in the target tissue [1]. PDT utilizes the property of certain photosensitizers to produce highly reactive singlet oxygen through illumination at non-toxic wavelengths, which renders the final therapeutic drug. Phthalocyanines are such photosensitizers that absorb in the far red spectrum of visible light and therefore are a promising tool in PDT[2,3]. These fluorescent dyes can also be used for imaging. The silicon based phthalocyanine Pc 4 is a second-generation photosensitizer for PDT with a maximum absorption at 675 nm and has been successfully applied in PDT[4,5].