Efficacy and safety of umbilical cord mesenchymal stem cells for the treatment of patients with COVID-19.

OBJECTIVES: The coronavirus disease (COVID-19) outbreak has catastrophically threatened public health worldwide and presented great challenges for clinicians. To date, no specific drugs are available against severe acute respiratory syndrome coronavirus 2. Mesenchymal stem cells (MSCs) appear to be a promising cell therapy owing to their potent modulatory effects on reducing and healing inflammation-induced lung and other tissue injuries. The present pilot study aimed to explore the therapeutic potential and safety of MSCs isolated from healthy cord tissues in the treatment of patients with COVID-19. METHODS: Twelve patients with COVID-19 treated with MSCs plus conventional therapy and 13 treated with conventional therapy alone (control) were included. The efficacy of MSC infusion was evaluated by changes in oxygenation index, clinical chemistry and hematology tests, immunoglobulin (Ig) levels, and pulmonary computerized tomography (CT) imaging. The safety of MSC infusion was evaluated based on the occurrence of allergic reactions and serious adverse events. RESULTS: The MSC-treated group demonstrated significantly improved oxygenation index. The area of pulmonary inflammation decreased significantly, and the CT number in the inflammatory area tended to be restored. Decreased IgM levels were also observed after MSC therapy. Laboratory biomarker levels at baseline and after therapy showed no significant changes in either the MSC-treated or control group. CONCLUSION: Intravenous infusion of MSCs in patients with COVID-19 was effective and well tolerated. Further studies involving a large cohort or randomized controlled trials are warranted.

Efficacy and safety of umbilical cord mesenchymal stem cells for the treatment of patients with COVID-19

OBJECTIVES: The coronavirus disease (COVID-19) outbreak has catastrophically threatened public health worldwide and presented great challenges for clinicians. To date, no specific drugs are available against severe acute respiratory syndrome coronavirus 2. Mesenchymal stem cells (MSCs) appear to be a promising cell therapy owing to their potent modulatory effects on reducing and healing inflammation-induced lung and other tissue injuries. The present pilot study aimed to explore the therapeutic potential and safety of MSCs isolated from healthy cord tissues in the treatment of patients with COVID-19. METHODS: Twelve patients with COVID-19 treated with MSCs plus conventional therapy and 13 treated with conventional therapy alone (control) were included. The efficacy of MSC infusion was evaluated by changes in oxygenation index, clinical chemistry and hematology tests, immunoglobulin (Ig) levels, and pulmonary computerized tomography (CT) imaging. The safety of MSC infusion was evaluated based on the occurrence of allergic reactions and serious adverse events. RESULTS: The MSC-treated group demonstrated significantly improved oxygenation index. The area of pulmonary inflammation decreased significantly, and the CT number in the inflammatory area tended to be restored. Decreased IgM levels were also observed after MSC therapy. Laboratory biomarker levels at baseline and after therapy showed no significant changes in either the MSC-treated or control group. CONCLUSION: Intravenous infusion of MSCs in patients with COVID-19 was effective and well tolerated. Further studies involving a large cohort or randomized controlled trials are warranted.

[Studies on the dispersion and deposition behavior of nano-TiO2 in aquatic system].

The existing form and environmental behavior of nTiO2 in aquatic system are mainly affected by environmental factors. The dispension and deposition behavior of nTiO2 was investigated by changing pH values of the suspension liquid and adding electrolytes and surfactants using P25 nano-TiO2 as the research object. The results indicated that the pH value obviously affected the stability of nTiO2 by changing the charge distribution on the nTiO2 particles. TiO2 nanoparticles were highly aggregated to deposit when the pH value was close to the isoelectric point. The characteristic adsorption ion of AlCl3, CaCl2, NaCl and Na2SO, after ionization on the surface of nTiO, particles varied from each other. The adsorption of cations neutralized the negative charge on the surface of nTiO2 particles which led to the quick aggregation and deposition of nTiO2 particles. The adsorption of anions improved the stability of nTiO2 particles in water by increasing electrostatic repulsion between TiO2 particles. Surfactants would adsorb onto the surface of nTiO2 particles and enhance the stability of nTiO, by changing the surface properties of the nanoparticles. The potential energy of nTiO2 particles were simulated by the DLVO theory. The simulative potential energy curve confirmed that the change of relevant water environment conditions led to the change of potential energy of nTiO, particles, which determined the dispension and deposition behavior of nTiO2 particles.