BackgroundNon-viral gene carriers because of their limited side effects, biocompatibility, simplicity and taking the advantages of electrostatic interactions have shown noticeable potential in gene delivery. The low transfection rate of non-viral vectors under physiological conditions is a significant issue. MethodsWe investigated the efficacy of hydrophilic and hydrophobic groups on gene carriers such as two synthesized amphiphilic polymer of dextran-stearic acid-spermine (DSASP) with verified lipid and amine conjugations that associated with Fe3O4 superparamagnetic nanoparticles to promote the target delivery and decrease the transfection time using static magnetic field.ResultsOur findings illustrate that magnetic nanoparticles are spherical with positive surface charges and superparamagnetic behaviors. The DSASP–pDNA/MNPs offered a strong pDNA condensation, protection against DNase degradation, significant cell viability in HEK 293T cells. Although conjugations of spermine play a critical role in transfection efficiency, amphiphilic polymer with more derivatives of stearic acid showed better transfection yields. ConclusionDSASP amphiphilic magnetic carriers offer new insights for gene delivery due to the amine contents and ameliorate the uptake of complexes via cell membrane based on its hydrophilic surface.

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Cryptochromes (CRYs) have been suggested to involve in the magnetic sensing for navigation of migratory birds in response to Earth’s magnetic fields. Magnetic fields (MFs) through wireless penetration change the cell physiology by effect on physicochemical reactions. Here, we aimed to investigate the behavior of HEK 293T cells overexpressing human CRY-based magnetoreception complexes undergo doxorubicin (DOX) treatment and exposure to moderate intensity static magnetic field (SMF) and extremely low frequency-pulsed electromagnetic field (ELF-PEMF). The ability of this magnetosensor is depended on CRY-photoreceptor proteins that complemented with putative magnetosensor proteins (MagR). The results indicate that magnetic sensitivity of CRY-based magnetosensor can effects on the intracellular reactive oxygen species (ROS) production and cell growth, cell cycle progression and expression of DNA damage-related genes due to treatment of DOX, SMF and ELF-PEMF. Our findings show that ROS accumulation significantly decreased in the cells expressing CRY/MagR complexes in response to all treatments, and also cell viability is decreased in contrast to MFs exposure. In addition, magnetosensitive complexes mediated the upregulation of genes in the base excision repair (BER) pathway including ITPA in presence of SMF as well as MTH1 in presence of ELF-PEMF in the DOX treated-cells. Furthermore, CRY/MagR induced a remarkable cell cycle arrest at G0/G1 phase in the all treatments. These results demonstrated that CRY/MagR complexes modify the DNA damage responses during genotoxic stresses by controlling the cell cycle progression and ROS levels. Therefore, our data suggest that CRY-based magnetosensitive complexes can increase the cytotoxic effects of DOX even when SMF and/or ELF-PEMF exposure were provided, exclusively.

TRPV channels are a category of nonselective cation channels that activated by heat and ligands, and permeate monovalent and divalent ions. The mechanism of Ca2+ transfer through TRPV2 channel is not well known. Here, we investigated the reaction coordination and energy fluctuation of Ca2+ transition in TRPV2 channel by steered molecular dynamics (SMD) simulations and potential of mean force (PMF) calculation. Results showed that electrostatic interactions between Ca2+ and residues of the first and second gates had main roles in ions transfer through the channel, and also, we recognized important amino acids in this path. Moreover, results indicated that enter and exit of calcium ions needed to overcome barrier energies in first and second gates.