In vitro comparative study of the effects of silver and gold nanoparticles exploitable in the context of photodynamic therapy

The studies about therapeutic applications of gold (AuNPs) and silver (AgNPs) NanoParticles, in conventional and non-conventional cancer therapies are gaining increased attention. PhotoDynamic Therapy (PDT) consists in the use of photosensitizers (PSs), which upon accumulation in tumor cells cause the death of malignant cells after irradiation with light. PDT respect conventional chemotherapy has minimal systemic toxicity since PSs possess high selectivity to cancer cells. In PDT, AuNPs and AgNPs can be used to enhance singlet oxygen (1O2) production from PSs by exploiting surface plasmon resonance phenomenon based on the interaction of the conduction electrons of metal nanostructures with incoming light. AuNPs are highly stable and biocompatible; conversely, AgNPs could release Ag+ ions. To avoid this, we use glucose as capping agents. The maximum absorption peak of AgNPs and AuNPs is at 420 and 530 nm, respectively. These peaks coincide with light wavelengths used in our previous works to excite Rose Bengal (RB) in HeLa cells. Our results highlight the potentiality of such nanostructures in PDT: both NPs enter HeLa cells, colocalize with RB and induce toxic effects upon green light irradiation. In particular, the presence of AuNPs and AgNPs enhance the 1O2. Moreover, the antiproliferative effect of AgNPs alone corroborates the possibility to synergize the toxic effects of PDT treatment against cancer cells.The studies about therapeutic applications of gold (AuNPs) and silver (AgNPs) NanoParticles, in conventional and non-conventional cancer therapies are gaining increased attention. PhotoDynamic Therapy (PDT) consists in the use of photosensitizers (PSs), which upon accumulation in tumor cells cause the death of malignant cells after irradiation with light. PDT respect conventional chemotherapy has minimal systemic toxicity since PSs possess high selectivity to cancer cells. In PDT, AuNPs and AgNPs can be used to enhance singlet oxygen (1O2) production from PSs by exploiting surface plasmon resonance phenomenon based on the interaction of the conduction electrons of metal nanostructures with incoming light. AuNPs are highly stable and biocompatible; conversely, AgNPs could release Ag+ ions. To avoid this, we use glucose as capping agents. The maximum absorption peak of AgNPs and AuNPs is at 420 and 530 nm, respectively. These peaks coincide with light wavelengths used in our previous works to excite Rose Be...