The influence of the surface chemistry of silver nanoparticles on cell death

Abstract

The influence of the surface chemistry of silver nanoparticles (AgNPs) on p53 mediated cell death was evaluated using human dermal fibroblast (HDF) and lung cancer (A549) cells. The citrate reduced AgNPs (C-AgNPs) were modified with either lactose (L-AgNPs) or a 12-base long oligonucleotide (O-AgNPs). Both unmodified and modified AgNPs showed increased concentration and time dependent cytotoxicity and genotoxicity causing an increased p53 up-regulation within 6 h and led to apoptotic or necrotic cell deaths. The C-AgNPs induced more cytotoxicity and cellular DNA damage than the surface modified AgNPs. Modifying the C-AgNPs with lactose or the oligonucleotide reduced both necrotic and apoptotic cell deaths in the HDF cells. The C-AgNPs caused an insignificant necrosis in A549 cells whereas the modified AgNPs caused necrosis and apoptosis in both cell types. Compared to the O-AgNPs, the L-AgNPs triggered more cellular DNA damage, which led to up-regulation of p53 gene inducing apoptosis in A549 cells compared to HDF cells. This suggests that the different surface chemistries of the AgNPs cause different cellular responses that may be important not only for their use in medicine but also for reducing their toxicity.

Photodynamic ability of silver nanoparticles in inducing cytotoxic effects in breast and lung cancer cell lines

“…The ability of AgNPs to generate such species led to phosphatidylserine externalization, DNA and nuclear fragmentation, mitochondria dysfunction, and caspase activity in cancer cells. 42,[46][47][48] The results suggest that the mode of cell death induced coincides with that found during photodynamic therapy. Although cell death due to photothermal effects has been identified, 49 the laser irradiation applied during this study does not support the induction of thermal effects.…”

Differential nanoreprotoxicity of silver nanoparticles in male somatic cells and spermatogonial stem cells

“…AgNPs activated the expression of the cell cycle checkpoint protein p53 and the DNA damage repair protein Rad51 in the treated cells (Figure 9), suggesting p53-mediated apoptosis. 96,97 Taken together, these data indicate that AgNPs induce apoptosis of TM3 and TM4 cells through activation of the p53 and MAPK pathways.…”

Central nervous system toxicity of metallic nanoparticles

“…That is, higher concentrations or doses can favor NP agglomeration in the absence of surface modifications to prevent spontaneous agglomeration due to close physical interactions of highly reactive NPs in concentrated colloidal liquids. 141 The resultant nanoaggregates as a whole can then hide or quench the originally hyperreactive surfaces of their smaller NP "parts". 142 Consequently, the specific larger agglomerated NP form is less toxic at a higher concentration than a lower dose of smaller but well-dispersed NPs, eg, NPs of PbS or copper.…”