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Tetanus is a specific infectious disease, often associated with lower immunization in developing countries and catastrophic events (such as earthquakes). Millions of people, especially children, die every year from tetanus disease. Therefore, it is necessary to devise a rapid and sensitive detection method for tetanus toxin to ensure an early diagnosis and clinical treatment of tetanus. The current study looks at developing a novel, high specific, low-cost, and sensitive ScFv antibody. It is capable of tetanus detection immunoassays in clinical diagnosis, suspicious foods, and water monitoring. For this regard, a high-quality phage display antibody library (8.7 × 107 PFU/ml) was constructed. Tetanus-specific antibodies with high affinity retrieved from libraries. After phage rescue and four rounds of biopanning, clone screening was performed by phage ELISA. Recombinant antibodies expressed from the AC8 clone showed the highest affinity for tetanus. SDS-PAGE and western blotting confirmed the presence of a high-quality, pure ScFv band at 32 kDa. ELISA was used to determine the affinity value, estimated to be around 10−8 M. The results suggest that the proposed detection method by ScFv antibodies is an alternative diagnostic tool enabling rapid and specific detection of the tetanus toxin. Graphical Abstract [ABSTRACT FROM AUTHOR]

Background and Objectives: Mesenchymal stem cells (MSCs)‐based regenerative therapy is now considered as an alternative approach to revive infectious diseases, including sepsis. Nevertheless, the efficiency of MSC application is limited by the poor survival rate of engrafted MSCs. Hence, preconditioning was established as a strategy to increase the cells' efficiency. Methods: MSCs were preconditioned with 1 μg/ml of three different lipopolysaccharides (LPSs) of Pseudomonas (Pse‐LPS), Acinetobacter (Ac‐LPS), and Acinetobacter inactivated lipid A by PagL (Ac‐LPS‐PagL). Then, preconditioned MSCs were exposed to oxidative stress and serum deprivation followed by evaluation of the antibacterial activity, survival, and apoptosis of MSCs. Then, the murine sepsis model treated with 100 μl phosphate‐buffered saline (control group, sepsis group), 100 μl of 1 × 10 6 wild MSCs (MSC group), and three remained groups received 100 μl of 1 × 10 6 LPS‐preconditioned MSCs (Pse‐LPS‐MSCs group: LPS purified from Pseudomonas, or Ac‐LPS‐MSCs group: LPS purified from Acinetobacter, and Ac‐PagL‐LPS‐MSCs group: detoxified LPS Pagl). Results: After 4 days, LPS‐preconditioned MSC transplantation modulated the immune response and reduced inflammation in septic mice. Apoptosis of Pse‐LPS/Ac‐LPS‐preconditioned‐MSCs was obviously reduced in vitro, and the survival rate of engrafted mice was evidently elevated in Pse‐LPS‐MSCs and Ac‐LPS‐MSCs groups compared with other three groups. Conclusion: LPS preconditioning provides an innovative strategy for evolving functional and biological properties of MSCs and ameliorates the survival rate of the mouse model of sepsis after MSC transplantation, protects cells from apoptosis and organ damages, and evaluates therapeutic properties, including immunemodulatory. Mesenchymal stem cells (MSCs)‐based regenerative therapy is now considered as an alternative approach to revive infectious diseases, including sepsis. In our study, lipopolysaccharides (LPS) preconditioning provides an innovative strategy for evolving functional and biological properties of MSCs and ameliorates the survival rate of the mouse model of sepsis after MSC transplantation, protects cells from apoptosis and organ damages, and evaluates therapeutic properties, including immunemodulatory. [ABSTRACT FROM AUTHOR]