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This research was carried out to evaluate the influence of static magnetic field on the rate of apoptosis in bone marrow stem cells (BMSCs) of rats. Extracted cells were suspended in aMEM as a culture media for 48 h. After that, cells were exposed to 15 mT static magnetic field (SMF) for 5 h, incessantly with or without FeCl 2 . The rate of apoptosis was then assessed via flow cytometery. The results showed that either treatment with FeCl 2 or exposure to SMF enhanced the rate of apoptotic cells. Moreover, cells that were treated simultaneously with FeCl 2 and SMF have higher rate of apoptosis. An increase in apoptosis by 26.5% was induced by SMF alone and an increase in apoptosis by 28.2% was induced by a combination of FeCl 2 and SMF, compared to their corresponding controls. The results recommended that the effects of SMF on apoptosis may be related to increment of the number of free radicals in the cells.

Detection of diphtheria toxin (DT) which is produced by Corynebacterium diphtheria, a zoonotic pathogen and a leading cause of diphtheria, is the critical step in the clinical laboratory. Traditional methods for DT detection are time consuming with low sensitivity. Herein, a localized surface plasmon resonance (LSPR) nanobioprobe has been developed based on specific immunological interactions between gold nanoparticles (GNPs) conjugated with monoclonal antibody and diphtheria toxoid in order for the rapid detection of DT. For this, plasmonic GNPs were conjugated to monoclonal antibodies covalently. The covalent conjugation has been confirmed by dynamic light scattering (DLS) and electrochemical techniques. Then, structural alterations of the conjugated antibody were monitored by circular dichroism (CD) and fluorescence spectroscopy methods. After that, the sensitivity of the nanobioprobe has been investigated via measuring the LSPR band λmax shifts of GNPs and LSPR sensitivity of nanobioprobe was compared with the ELISA method. Results suggested that this assay is highly selective and sensitive with a lower detection limit of about 10 ng/mL. The LSPR biosensor reduced the DT detection time from 2 or 3 days to less than 1 h compared with traditional methods. In conclusion, the investigation presents a rapid, sensitive, and selective method for the diagnosis of DT in clinical specimens.

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