Protoporphyrin IX-Gold Nanoparticle Conjugates for Targeted Photodynamic Therapy-An In-Vitro Study

Targeted drug delivery system using nanoparticles is a promising strategy for efficient Photodynamic therapy (PDT) as they have the potential to overcome the problems of photosensitizer and enhance the effectiveness and specificity of PDT. In this study, Protoporphyrin IX (PpIX) conjugated gold nanoparticles were synthesized using electrostatic and covalent conjugation scheme. Folic acid (FA) was also conjugated suitably to the covalent complex to vectorize the complex. Optical characterizations of the complex prove the formation of the complex. The size of the synthesized nanocomplexes was studied using light scattering measurements. The photo-toxicity of the free PpIX and PpIX-nanoparticle complexes were studied using MIT assay technique against Vero and HeLa cell lines. These In-vitro results of this study indicates that, the nanoparticle complexes are more phototoxic compared to free PpIX, with the covalent complex being the better of the two complexes and the folate-mediated nanocomplex is the superior of the studied complexes. These results ensures that nanoparticle conjugated photosensitizers equipped with FA may be an effective drug delivery mechanism for PDT.