Xinrui Jin

Terahertz (THz) wave is a promising and newly developed technology in biological medicine, especially in neuro-related treatments and devices. The effects of THz waves on ion channels are being revealed. However, the effect of THz waves on Ca2+ and surrounding hydration shells has not been clearly researched yet, restricting the understanding of THz waves’ effects on the Ca2+ permeation process in channel structures, such as ion channels. Thus, in this work, we carried out molecular dynamics simulations to fully explore the resonant effects of THz waves on (1) hydrogen bonding among the hydration shells of Ca2+ and (2) desolvation energy of each hydration shell while permeating through an ion channel. Our work indicates that a 14.5 THz wave will remold the hydrogen bonding pattern of the second and third hydration shells, weaken the effect of water dipole reorientation effects of the first and second hydration shells, and increase the desolvation energy of the second and third hydration shells. This work expands the method to estimate the ionic desolvation energy under specific conditions and further increases our cognitions on the effects of THz waves on the structure of the Ca2+ hydration shell and its hydrogen bond pattern.

Terahertz waves, owing to the special feature of inducing resonance with numerous biomolecules, thus affecting biological activities, have become a novel and promising biological technology. Recently, the effect of terahertz waves on neuroscience via ion channel proteins on the cell membrane has received more attention. A cell membrane model with the voltage-gated calcium channel Cav1.1 embedded was constructed. The vibrational spectra of TIP3P molecules and carboxyl and carbonyl groups in the selectivity filter region (13.4, 48.7, and 53.2 THz) were calculated. The change in ion channel pore radius distribution and secondary structures of Cav1.1 triggered by external terahertz electromagnetic fields are measured. The umbrella sampling method is carried out to assess the functional changes of Cav1.1 via potential of mean force profiles of Ca2+ permeation. The results showed that Cav1.1 has highly frequency specificity, emphasizing the importance of terahertz resonance with biomolecules in terahertz-related neuroscience research.

Cold atmospheric plasma (CAP) is considered to be a highly promising cancer treatment method, due to its “selective” anti-cancer effect. However, the physical theoretical explanation about this effect and the microscopic interactive mechanisms between CAP and tumors are still lacking. In this work, the CAP-induced electric field-caused electroporation (EP) processes of the cell membrane are modeled based on molecular dynamics. Additionally, the umbrella sampling method is utilized to compute the free energy profile of the intracellular permeation processes of the reactive oxygen species (ROS) through EP-formed pore-like structures at different EP stages. Comparative results are shown as follows. 1) Cancer cell membranes with lower cholesterol components show lower EP-generation threshold and faster EP-formation, and 2) lower free-energy barrier and earlier occurrence of free-energy barrier reduction are shown in all EP stages in cancer cell membrane. The above results explain the difference between cancer cells and normal cells when affected by CAP. Our work delves into the formation of CAP-induced EP and the transport of ROS through EP-formed pore-like structures, which contributes to a better understanding of the microscopic mechanisms of the “selective” anti-cancer effect of CAP, and provides important references for developing CAP-based cancer treatment methods, and devices, thereby facilitating the translation of CAP into clinical applications.

The transforming growth factor beta (TGF-β) signaling pathway is believed to play essential roles in several physiological activities, including cancer. TGF-β receptor type I (TBR-I) is a key membrane receptor protein in the TGF-β signaling pathway, which relates to many intracellular biological effects. In recent years, cold atmospheric plasma (CAP) has been found to have promising prospects in selective anticancer therapy and has confirmed its essential role in the TGF-β signaling pathway. However, the ambiguous effect of CAP-induced electric field (EF) on TBR-I still limits the application of CAP in clinical therapy. Molecular dynamics is applied to assess the effect of EF on the structure of the extracellular domain of TBR-I using a series of indicators and methods, and then we discuss the ligand binding ability of TBR-I. Results show that moderate EF intensities' structural restraints may contribute to the structural stability and ligand-binding ability of TBR-I, but an EF higher than 0.1 V/nm will be harmful. What's more, EF induces a change in the docking interface of TBR-I, showing the conformation and position of special sequences of residues decide the ligand binding surface. The relevant results suggest that CAP-induced EF plays a crucial role in receptor-receptor interaction and provides significant guidelines for EF-related anticancer therapy.Communicated by Ramaswamy H. Sarma.