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Aim: Exosomal damage-associated molecular patterns can play a key role in immunostimulation and changing the cold tumor microenvironment to hot. Materials & methods: This study examined the immunostimulation effect of photothermal and hyperthermia-treated 4T1 cell-derived exosomes on 4T1 cell-induced breast tumors in BALB/c animal models. Exosomes were characterized for HSP70, HSP90 and HMGB-1 before injection into mice and tumor tissues were analyzed for IL-6, IL-12 and IL-1β, CD4 and CD8 T-cell permeability, and PD-L1 expression. Results: Thermal treatments increased high damage-associated molecular patterns containing exosome secretion and the permeability of T cells to tumors, leading to tumor growth inhibition. Conclusion: Photothermal-derived exosomes showed higher damage-associated molecular patterns than hyperthermia with a higher immunostimulation and inhibiting tumor growth effect. This research explored the impact of using tiny dying cancer cell-derived particles known as exosomes to activate the immune system to fight against breast tumors in animal models. These exosomes contain specific molecules that can trigger the immune response and alter the environment surrounding the tumor. Researchers applied two different treatments, photothermal and hyperthermia, to kill the cancer cells and obtain these exosomes. Both treatments involved using heat to kill the cells. The study revealed that exosomes derived through the photothermal method exhibited higher levels of these immune-activating molecules compared with those obtained through hyperthermia. Upon injecting these exosomes into the animal models, they enhanced the ability of the immune cells to enter the tumors, resulting in a reduction in tumor growth. Overall, the findings indicate that using exosomes obtained through the photothermal method may be more effective in stimulating the immune system to fight against cancer and inhibiting tumor growth, as opposed to using exosomes obtained through hyperthermia. [ABSTRACT FROM AUTHOR]

Simple Summary: Tumor cell-derived extracellular vesicles (TEVs) are an important means of tumor communication with, and manipulation of, the patient's physiology. TEVs influence the local tumor environment as well as the systemic conditions of the patient. Progressive changes in tumor interactions with the host immune system are defined as "immunoediting". Here, we summarize TEV effects on the immune system during the stages of cancer immunoediting and outline the molecular and cellular characteristics of interactions that result in complete tumor regression versus tumor immune escape and progression. Generally, the cargo profile of TEVs naturally changes during immunoediting toward immunosuppression while different cell stress or treatment conditions can inhibit this process or even reverse it to immunostimulation by altering the TEVs cargos. Therefore, understanding potential immunotherapeutic properties and how they can be manipulated to treat cancer should be considered a new research approach in oncoimmunotherapy. The tumor microenvironment (TME) within and around a tumor is a complex interacting mixture of tumor cells with various stromal cells, including endothelial cells, fibroblasts, and immune cells. In the early steps of tumor formation, the local microenvironment tends to oppose carcinogenesis, while with cancer progression, the microenvironment skews into a protumoral TME and the tumor influences stromal cells to provide tumor-supporting functions. The creation and development of cancer are dependent on escape from immune recognition predominantly by influencing stromal cells, particularly immune cells, to suppress antitumor immunity. This overall process is generally called immunoediting and has been categorized into three phases; elimination, equilibrium, and escape. Interaction of tumor cells with stromal cells in the TME is mediated generally by cell-to-cell contact, cytokines, growth factors, and extracellular vesicles (EVs). The least well studied are EVs (especially exosomes), which are nanoparticle-sized bilayer membrane vesicles released by many cell types that participate in cell/cell communication. EVs carry various proteins, nucleic acids, lipids, and small molecules that influence cells that ingest the EVs. Tumor-derived extracellular vesicles (TEVs) play a significant role in every stage of immunoediting, and their cargoes change from immune-activating in the early stages of immunoediting into immunosuppressing in the escape phase. In addition, their cargos change with different treatments or stress conditions and can be influenced to be more immune stimulatory against cancer. This review focuses on the emerging understanding of how TEVs affect the differentiation and effector functions of stromal cells and their role in immunoediting, from the early stages of immunoediting to immune escape. Consideration of how TEVs can be therapeutically utilized includes different treatments that can modify TEV to support cancer immunotherapy. [ABSTRACT FROM AUTHOR]

Students working in nanotechnology laboratories could expose to nanomaterials during production, handling, and transportation of these materials. Studies have shown that nanomaterials have adverse effects on humans. So, this study was conducted to investigate the status of nanotechnology laboratories and also to examine students' non-specific symptoms. This cross-sectional study was conducted in nanotechnology laboratories of 8 universities of medical sciences. Two questionnaires were used for data collection. A questionnaire was used to assess the status of laboratories and another to assess the non-specific symptoms of students. Finally, data were analyzed using SPSS 22.0. Results showed that only %33.7 of the laboratories had nanomaterials safety and health policy, while %63.6 of them reported the existence of general health and safety policy. Examination of the parameters affecting the exposure showed that in the studied laboratories, the ground for significant exposure to nanomaterials is provided. Study of transportation and storage of nanomaterials in the laboratories showed a relatively good situation. In terms of controls, condition was not favorable. The most reported symptoms among students were cutaneous, ocular, neurological, and respiratory symptoms, respectively. Comparing the status of the studied laboratories and the standards of nanotechnology laboratories, these laboratories are far from the ideal situation. Training the principles of working safely with nanomaterials, improving engineering controls, and providing appropriate PPEs for nanomaterials and using them properly, can effectively improve the laboratories, reduce exposure and reduce symptoms among the students. [ABSTRACT FROM AUTHOR]