Advances in nanotechnology have led to an increased use of engineered nanoparticles (ENPs) and the likelihood for occupational exposures. However, how to assess such exposure remains a challenge. In this study, a methodology for human biomonitoring, based on Single Particle Inductively Coupled Plasma Mass Spectrometry (SP-ICP-MS), was developed as a tool to assess the ENPs exposure of workers involved in nanomaterial activities in two Italian Companies. The method was validated for size and number concentration determination of Ag, Au, In₂O₃, Ir, Pd, Pt, and TiO₂ NPs in urine and blood samples. The results showed the presence of In₂O₃ NPs in blood of exposed workers (mean, 38 nm and 10,371 particles/mL), but not in blood of controls. Silver, Au, and TiO₂ NPs were found in urine (mean, Ag 29 nm and 16,568 particles/mL) or blood (mean, Au 15 nm and 126,635 particles/mL; TiO₂ 84 nm and 27,705 particles/mL) of workers, though these NPs were found also in controls. The presence of ENPs in both workers and controls suggested that the extra-professional exposure is a source of ENPs that cannot be disregarded. Iridium, Pd, and Pt NPs were not detected neither in blood nor in urine. Overall, the findings provided a rational basis to evaluate the exposure assessment to ENPs in cohorts of workers as part of risk assessment and risk management processes in workplaces.

The HPV16 E7 protein is both a tumour-specific and a tumour-rejection antigen, the ideal target for developing therapeutic vaccines for the treatment of HPV16-associated cancer and its precursor lesions. E7, which plays a key role in virus-associated carcinogenesis, contains 98 amino acids and has two finger-type structures which bind a Zn++ ion. The ability of an Escherichia coli-produced E7-preparation, assembled into particles, to induce protective immunity against a HPV16-related tumour in the TC-1-C57BL/6 mouse tumour model, was evaluated.

Tattoo inks contain varying amounts of metal nanoparticles (NPs) < 100 nm that, due to their unique physicochemical properties, may have specific biological uptake and cause skin or systemic toxicities. The toxic effects of certified reference standards of metal NPs and samples of commercially available tattoo inks were investigated using an in vitro system and a novel human ex vivo model. In vitro toxicity was evaluated using vitality assays on human skin cells (HaCaT cell line, primary fibroblasts, and keratinocytes). No toxicity was observed for Al₂O₃, Cr₂O₃, Fe₂O₃, and TiO₂ NPs, whereas CuO NPs showed dose-dependent toxicity on HaCaT and primary fibroblasts. Fibroblasts and keratinocytes were also sensitive to high concentrations of ZnO NPs. Reference standards and ink samples were then injected ex vivo into human skin explants using tattoo needles. Histological analysis showed pigment distribution deep in the dermis and close to dermal vessels, suggesting possible systemic diffusion. The presence of an inflammatory infiltrate was also observed. Immunohistochemical analysis showed increased apoptosis and expression of the inflammatory cytokine interleukin-8 in explants specifically tattooed with the reference standard or red ink. Taken together, the results suggest that the tattooing technique leads to exposure to toxic metal NPs and skin damage.