Exhibiting a red-shifted absorption/scattering feature compared to conventional plasmonic metals, titanium nitride nanoparticles (TiN NPs) look as very promising candidates for biomedical applications, but these applications are still underexplored despite the presence of extensive data for conventional plasmonic counterparts. Here, we report the fabrication of ultrapure, size-tunable TiN NPs by methods of femtosecond laser ablation in liquids and their biological testing. We show that TiN NPs demonstrate strong and broad plasmonic peak around 640–700 nm with a significant tail over 800 nm even for small NPs sizes (<7 nm). In vitro tests of laser-synthesized TiN NPs on cellular models evidence their low cytotoxicity and excellent cell uptake. We finally demonstrate a strong photothermal therapy effect on U87–MG cancer cell cultures using TiN NPs as sensitizers of local hyperthermia under near-infrared laser excitation. Based on absorption band in the region of relative tissue transparency and acceptable biocompatibility, laser-synthesized TiN NPs promise the advancement of biomedical modalities employing plasmonic effects, including absorption/scattering contrast imaging, photothermal therapy, photoacoustic imaging and SERS.

Objectives To describe the clinical characteristics and management of residents in French nursing homes with suspected or confirmed coronavirus disease 2019 (COVID-19), and to determine the risk factors for COVID-19-related hospitalization and death in this population. Design A retrospective multicenter cohort study Setting and Participants Four hundred and eighty nursing home residents with suspected or confirmed COVID-19 between 1 March and 20 May 2020 were enrolled and followed until 2 June 2020 in 15 nursing homes in Marseille’s greater metropolitan area. Methods Demographic, clinical, laboratory, treatment type, and clinical outcome data were collected from patients’ medical records. Multivariable analyses were used to determine factors associated with COVID-19-related hospitalization and death. For the former, the competing risk analysis - based on Fine and Gray’s model - took death into account. Results 480 residents were included. Median age was 88 years (IQR 80-93), and 330 residents were women. A total of 371 residents were symptomatic (77.3%), the most common symptoms being asthenia (47.9%), fever or hypothermia (48.1%), and dyspnea (35.6%). One hundred and twenty-three patients (25.6%) were hospitalized and 96 (20%) died. Male gender (sHR 1.63, 95% CI 1.12-2.35), diabetes (sHR 1.69, 95% CI 1.15-2.50), an altered level of consciousness (sHR 2.36, 95% CI 1.40-3.98), and dyspnea (sHR 1.69, 95% CI 1.09-2.62) were all associated with a greater risk of COVID-19-related hospitalization. Male gender (OR 6.63, 95% CI 1.04-42.39), thermal dysregulation (OR 2.64, 95% CI 1.60-4.38), falls (2.21 95% CI 1.02-4.75), and being aged >85 years old (OR 2.36 95% CI 1.32-4.24) were all associated with increased COVID-19-related mortality risk, whereas polymedication (OR 0.46, 95% CI 0.27-0.77) and preventive anticoagulation (OR 0.46, 95% CI 0.27-0.79) were protective prognostic factors. Conclusions and Implications Male gender, being aged >85 years old, diabetes, dyspnea, thermal dysregulation, an altered level of consciousness, and falls, must all be considered when identifying and protecting nursing home residents who are at greatest risk of COVID-19-related hospitalization and death.