Assessment of absorbed dose of gamma rays using the simultaneous determination of inactive hemoglobin derivatives as a biological dosimeter

Low Dose Soft X-Ray Remotely Triggered Lanthanide Nanovaccine for Deep Tissue CO Gas Release and Activation of Systemic Anti-Tumor Immunoresponse

Gas-based therapy has emerged as a new green therapy strategy for anti-tumor treatment. However, the therapeutic efficacy is still restricted by the deep tissue controlled release, poor lymphocytic infiltration, and inherent immunosuppressive tumor microenvironment (TME). Herein, a new type of nanovaccine is designed by integrating low dose soft X-ray-triggered CO releasing lanthanide scintillator nanoparticles (ScNPs: NaLuF4 :Gd,Tb@NaLuF4 ) with photo-responsive CO releasing moiety (PhotoCORM) for synergistic CO gas/immuno-therapy of tumors. The designed nanovaccine presents significantly boosted radioluminescence and enables deep tissue CO generation at unprecedented tissue depths of 5 cm under soft X-ray irradiation. Intriguingly, CO as a superior immunogenic cell death (ICD) inducer further reverses the deep tissue immunosuppressive TME and concurrently activates adaptive anti-tumor immunity through efficient reactive oxygen species (ROS) generation. More importantly, the designed nanovaccine presents efficient growth inhibition of both local and distant tumors via a soft X-ray activated systemic anti-tumor immunoresponse. This work provides a new strategy of designing anti-tumor nanovaccines for synergistic deep tissue gas-therapy and remote soft X-ray photoactivation of the immune response.

Potential role of cytoplasmic protein binding to erythrocyte membrane in counteracting oxidative and metabolic stress

The ability of protein to reversibly bind with membrane components is considered to be one of the oldest mechanisms of cell response to external stimuli. Erythrocytes have a well-developed mechanism of an adaptive response involving sorption-desorption processes, e.g. interactions of key glycolytic enzymes and hemoglobin with band 3 protein. A few publications have shown that under oxidative stress, cytoplasmic enzymes such as catalase, glutathione peroxidase and рeroxiredoxin bind to the erythrocyte membrane. The present work is a continuation of research in this direction to determine the causes and consequences of the interaction of cytoplasmic proteins with the membrane under conditions of oxidative stress and different glucose content. Human erythrocytes were incubated for five hours at 20 °C in an oxidizing medium of AscH – 1 · 10–4 M, Cu2+– 5 · 10–6 M with different glucose content (0–8 mM). Dynamic changes in the accumulation of membrane-bound hemoglobin, the distribution of ligand forms of hemoglobin in the cytoplasmic and membrane-bound fractions, the activity of membrane-associated and cytoplasmic forms of Cu/Zn superoxide dismutase (SOD1) and catalase, H2O2 content in extracellular and intracellular media were recorded. It was shown that binding of catalase and SOD1 to the erythrocyte membrane is initiated by oxidative stress and is a physiological function aimed at complete inactivation of extracellular and H2O2 and protection against their entry into the cell. It was shown that under conditions of glucose depletion and oxidative loading, catalase and SOD1 bind to the erythrocyte membrane, leading to inactivation of these enzymes. Membrane-bound hemoglobin was higher in cells incubated under these conditions than in glucose experiments. Glucose introduced into the incubation medium in an amount 4–8 mM causes complete binding of SOD1 to the membrane of erythrocytes, by involving it in the processes of casein kinase stabilization and glycolytic fluxes regulation. With mild oxidation, the amount of hemoglobin bound to the membrane does not change, indicating the presence of certain binding sites for hemoglobin with membrane proteins. We show that the activity of membrane-bound SOD1 along with the content of ligand forms in the composition of membrane-bound hemoglobin are informative indicators of the metabolic and redox state of erythrocytes.