Chlorine e6 in phospholipid nanoparticles with specific targeting and penetrating peptides as prospective composition for photodynamic therapy of malignant neoplasms
Cytotoxic and photoinduced activity of chlorine e6 (Ce6) in phospholipid nanoparticles with specific tumor targeting and cell-penetrating peptides was studied in vitro using human fibrosarcoma cells HT-1080. It was shown, that the binding of cell-penetrating peptide R7 - alone or combined with the peptide containing specific targeting motif NGR (Asn-Gly-Arg) - resulted in 3-fold decrease of Ce6 photoinduced activity as compared with that in nanoparticles without peptides (IC50 values were 0.7 μg/ml and 2.1 μg/ml, respectively). The NGR influence was unexpectedly low - less than 20% (IC50 1.7 μg/ml). This suggests the more importance of Ce6 cell penetration in this case, than of NGR-mediated targeting. The effect of inclusion of both peptides on the total cytotoxicity of Ce6 was minimal (10-16 times less than on the specific photoinduced activity). The obtained results - together with earlier shown effects on improvement of the pharmacokinetics of Ce6 in vivo after its embedding into phospholipid nanoparticles - indicate the prospects of using the obtained phospholipid nanoparticles system for photodynamic therapy.