Significance: An increasing interest in the area of biological effects at exposure of tissues and cells to the terahertz (THz) radiation is driven by a rapid progress in THz biophotonics, observed during the past decades. Despite the attractiveness of THz technology for medical diagnosis and therapy, there is still quite limited knowledge about safe limits of THz exposure. Different modes of THz exposure of tissues and cells, including continuous-wave versus pulsed radiation, various powers, and number and duration of exposure cycles, ought to be systematically studied. Aim: We provide an overview of recent research results in the area of biological effects at exposure of tissues and cells to THz waves. Approach: We start with a brief overview of general features of the THz-wave–tissue interactions, as well as modern THz emitters, with an emphasis on those that are reliable for studying the biological effects of THz waves. Then, we consider three levels of biological system organization, at which the exposure effects are considered: (i) solutions of biological molecules; (ii) cultures of cells, individual cells, and cell structures; and (iii) entire organs or organisms; special attention is devoted to the cellular level. We distinguish thermal and nonthermal mechanisms of THz-wave–cell interactions and discuss a problem of adequate estimation of the THz biological effects’ specificity. The problem of experimental data reproducibility, caused by rareness of the THz experimental setups and an absence of unitary protocols, is also considered. Results: The summarized data demonstrate the current stage of the research activity and knowledge about the THz exposure on living objects. Conclusions: This review helps the biomedical optics community to summarize up-to-date knowledge in the area of cell exposure to THz radiation, and paves the ways for the development of THz safety standards and THz therapeutic applications.

中文翻译：

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太赫兹波的细胞效应


意义：过去几十年来，太赫兹生物光子学的快速进展推动了人们对组织和细胞暴露于太赫兹（THz）辐射的生物效应领域越来越感兴趣。尽管太赫兹技术对于医学诊断和治疗具有吸引力，但关于太赫兹暴露的安全限度的知识仍然相当有限。应该系统地研究组织和细胞的不同太赫兹暴露模式，包括连续波与脉冲辐射、各种功率以及暴露周期的数量和持续时间。目的：我们概述了组织和细胞暴露于太赫兹波的生物效应领域的最新研究成果。方法：我们首先简要概述太赫兹波与组织相互作用的一般特征以及现代太赫兹发射器，重点是那些对于研究太赫兹波的生物效应可靠的特征。然后，我们考虑生物系统组织的三个层次，在这三个层次上考虑暴露效应：（i）生物分子的溶液； (ii) 细胞、单个细胞和细胞结构的培养物； (iii) 整个器官或生物体；特别关注细胞水平。我们区分了太赫兹波与细胞相互作用的热机制和非热机制，并讨论了充分估计太赫兹生物效应特异性的问题。还考虑了由于太赫兹实验装置稀有和缺乏统一协议而导致的实验数据再现性问题。结果：总结的数据展示了当前阶段的研究活动和有关生命体太赫兹暴露的知识。 结论：本综述有助于生物医学光学界总结太赫兹辐射细胞暴露领域的最新知识，并为制定太赫兹安全标准和太赫兹治疗应用铺平道路。