Neutrophils are the first to reach the site of infection as they are the most numerous and dominant pathogen-killing cells in the circulatory system. They are both involved in initial immunity and act as effector cells in destructive inflammatory responses. The abundance of neutrophils in the human body and their inherent properties give them the ability to target inflammatory sites for drug delivery, and their important role in the inflammatory response has led to increasing attention to the therapeutic potential of neutrophils. In this review paper, the research progress in neutrophil-mediated drug delivery systems is reviewed, including the use of neutrophils as carriers, neutrophil exosomes as carriers, and in vivo targeted delivery of drugs using neutrophil properties.

Objective To investigate the present situation of radiation environment in Beijing and provide data support for monitoring and management of radiation environment in Beijing. Methods The γ radiation dose rate of environmental surface as well as the radioactive levels of aerosol, sediment, surface water, and soil samples were monitored in Beijing from 2015 to 2022. The radioactive levels of various environmental elements in this area were presented using statistical charts and statistical tables, and the related issues were discussed. Results The automatic monitoring and cumulative monitoring results of γ radiation dose rate were in the range of local natural background fluctuation. The radioactive levels of beryllium-7, lead-210, and polonium-210 in aerosols were low in summer and high in winter. The radioactive levels of total α, total β, and beryllium-7 in sediments were low in winter and high in summer. The activity concentration of radionuclide potassium-40 in aerosols and sediments did not change significantly with seasons. The total α and total β radioactivity levels of surface water fluctuated within the range of background. These values of reservoir water were within the limits specified in the Hygienic Standard for Drinking Water (GB 5749—2006). Natural radionuclides in soil were within the range of natural background fluctuation, and artificial radionuclides in soil were within the range of normal fluctuation over the years. Conclusion From 2015 to 2022, the environmental surface γ radiation dose rate as well as aerosol, sediment, surface water, and soil radioactivity levels in Beijing were generally low, all of which fluctuated within the environmental background.

Objective To investigate and evaluate the changes in total α and total β radioactivity levels in drinking water in Beijing, China, 2012—2021. Methods The test results of total α and total β radioactivity levels at 14 monitoring sites from 9 groundwater sources and 5 surface water sources in Beijing, 2012—2021 were collected. The radioactivity levels in the two types of water sources were compared. Statistical charts were used to show the monitoring situation at sampling sites in different regions during different periods, and related issues were explored. Results The total α and total β activity concentrations measured at monitoring sites from some water sources in Beijing, 2012—2021, were less than the total α and total β guideline values specified in the Standards for Drinking Water Quality (GB 5749—2006) (total α: 0.5 Bq/L, total β: 1.0 Bq/L). The mean total α activity concentration in the groundwater was significantly higher than that in the surface water. The total α and total β radioactivity levels in the reservoir D in the surface water were slightly higher than those in the other surface water. Conclusion In the past decade from 2012 to 2021, the total α and total β radioactivity levels in some water sources in Beijing were generally in a good condition and fluctuated within the range of environmental background values, without significant changes on the whole.