New technologies launch novel materials; besides their performances in products, their health hazards must be tested. This applies to the lead halide perovskite CHNHPbI as well, which offers fulgurate applications in photovoltaic devices. We report the effects of CHNHPbI photovoltaic perovskites in human lung adenocarcinoma epithelial cells (A549), human dopaminergic neuroblastoma cells (SH-SY5Y) and murine primary hippocampal neurons by using multiple assays and electron microscopy studies. In cell culture media the major part of the dissolved CHNHPbI has a strong cell-type dependent effect. Hippocampal primary neurons and neuroblastoma cells suffer a massive apoptotic cell death, whereas exposure to lung epithelial cells dramatically alters the kinetics of proliferation, metabolic activity and cellular morphology without inducing noticeable cell death. Our findings underscore the critical importance of conducting further studies to investigate the effect of short and long-term exposure to CHNHPbI on health and environment.

Stiffness tomography is a new atomic force microscopy imaging technique that allows highlighting structures located underneath the surface of the sample. In this imaging mode, such structures are identified by investigating their mechanical properties. We present here, for the first time, a description of the use of this technique to acquire detailed stiffness maps of fixed and living macrophages. Indeed, the mechanical properties of several macrophages were studied through stiffness tomography imaging, allowing some insight of the structures lying below the cell's surface. Through these investigations, we were able to evidence the presence and properties of stiff column-like features located underneath the cell membrane. To our knowledge, this is the first evidence of the presence, underneath the cell membrane, of such stiff features, which are in dimension and form compatible with phagosomes. Moreover, by exposing the cells to cytochalasin, we were able to study the induced modifications, obtaining an indication of the location and mechanical properties of the actin cytoskeleton.

We studied the effect of the exposure of human A549 and SH-SY5Y cell lines to aqueous solutions of organic/inorganic halide perovskites CH3NH3PbI3 (MAPbI3) and CH3NH3SnI3 (MASnI3) at the molecular level by using Fourier transform infrared microspectroscopy. We monitored the infrared spectra of some cells over a few days following exposure to the metals and observed the spectroscopic changes dominated by the appearance of a strong band at 1627 cm−1. We used Infrared (IR) mapping to show that this change was associated with the cell itself or the cellular membrane. It is unclear whether the appearance of the 1627 cm−1 band and heavy metal exposure are related by a direct causal relationship. The spectroscopic response of exposure to MAPbI3 and MASnI3 was similar, indicating that it may arise from a general cellular response to stressful environmental conditions. We used 2D correlation spectroscopy (2DCOS) analysis to interpret spectroscopic changes. In a novel application of the method, we demonstrated the viability of 2DCOS for band assignment in spatially resolved spectra. We assigned the 1627 cm−1 band to the accumulation of an abundant amide or amine containing compound, while ruling out other hypotheses. We propose a few tentative assignments to specific biomolecules or classes of biomolecules, although additional biochemical characterization will be necessary to confirm such assignments.

We use Fourier-Transform infrared spectromicroscopy to study at the molecular level the effect of exposure of human A549 and SH-SY5Y cell lines to the perovskites CH3NH3PbI3 (MAPbI3) and CH3NH3SnI3 (MASnI3). By monitoring the infrared absorption of amide bands over a few days following exposure to the metals, we observe the appearance of a strong band at 1628 cm -1 . This band is tentatively assigned to the extensive formation of intermolecular β-sheet structures. A similar response is observed after exposure of the cells to CuSO4, suggesting that the mechanism underlying the observed spectroscopic changes is not specific for Pb 2+ and Sn 2+ , and it may be associated to a generic cellular response to stressful environmental conditions.

We use Fourier-Transform infrared spectromicroscopy to study at the molecular level the effect of exposure of human A549 and SH-SY5Y cell lines to the perovskites CH₃NH₃PbI₃ (MAPbI₃) and CH₃NH₃SnI₃ (MASnI₃). By monitoring the infrared absorption of amide bands over a few days following exposure to the metals, we observe the appearance of a strong band at 1628 cm-1. This band is tentatively assigned to the extensive formation of intermolecular β-sheet structures. A similar response is observed after exposure of the cells to CuSO₄, suggesting that the mechanism underlying the observed spectroscopic changes is not specific for Pb²⁺ and Sn²⁺, and it may be associated to a generic cellular response to stressful environmental conditions.<br>