A template-free assembly of Cu,N-codoped hollow carbon nanospheres as low-cost and highly efficient peroxidase nanozymes.

Developing carbon-based materials with high catalytic performance and sensitivity has significance in low-cost and highly efficient nanozymes. Herein, for the first time, Cu,N-codoped hollow carbon nanospheres (CuNHCNs) with highly active Cu-Nx sites were successfully assembled through a template-free strategy, in which Cu2+-poly(m-phenylenediamine) (Cu-PmPD) nanospheres were utilized as the source of Cu, N and C. Benefiting from the synergistic effect of the hollow spherical structure and optimized composition, the CuNHCN exhibits high affinity for 3,3',5,5'-tetramethylbenzidine and H2O2 with 0.0655 mM and 0.918 mM, respectively, which are superior to those of HRP and most metal-based nanozymes. Moreover, by employing glucose and ascorbic acid (AA) as biomolecule models, a CuNHCN-based colorimetric detection platform is developed. The CuNHCN exhibits superior peroxidase mimicking activity and sensitivity in detecting glucose and AA with a detection limit of 0.187 µM and 68.9 nM (S/N = 3), respectively. Also, the colorimetric detection based on the CuNHCN towards glucose and AA in human serum presents superior practicability and accuracy. The assay provides a new avenue for designing and fabricating low-cost peroxidase nanozymes with high performance in bioassays.

Effectiveness of umbilical cord mesenchymal stem cells in patients with critical limb ischemia / Efectividad de las células madre mesenquimales del cordón umbilical en pacientes con isquemia crítica de extremidades

Introduction and objective: Transplantation of umbilical cord mesenchymal stem cells (UC-MSCs) has been shown to be effective in treating critical limb ischemia (CLI). However, the mechanism of MSCs-mediated improvements, especially on the immune-inflammatory aspects of this disease, is still unknown. In this study, we investigated the changes in T-lymphocyte subpopulations and inflammatory mediators (such as IL-6, IL-10 and TNF-alpha) in PBMCs from CLI patients after UC-MSCs treatment and correlation between inflammatory mediators and EPCs. Patients and methods: 8 patients received UC-MSCs transplantation. Before the treatment, at 24h and 1 month thereafter, peripheral blood samples were collected from 8 patients and 8 healthy volunteers. Patients were evaluated for changes in IL-6, IL-10, TNF-alpha and levels of circulating EPCs. Results: TNF-alpha and IL-6 serum levels increased at 24h (p=0.017, p=0.099) after treatment and then decreased at 1 month (p=0.031, p=0.072) compared with those before treatment. The percentages of CD3+T, CD3+CD4+T-lymphocytes and NK cells decreased significantly after UC-MSCs treatment (p=0.002, p=0.012 and p=0.029, respectively). TNF-alpha (r=−0.602, p=0.038) was shown to be inversely correlated with the number of circulating EPCs. Conclusions: This study demonstrates that UC-MSCs have anti-inflammatory and immunomodulation properties in CLI and suggests that UC-MSCs promote healing of non-healing wounds

Introducción y objetivo: El trasplante de células madre mesenquimales del cordón umbilical (CMM-CU) ha demostrado eficacia en el tratamiento de la isquemia crítica de las extremidades (ICE). Sin embargo, se desconoce el mecanismo de las mejoras mediadas por las CMM, especialmente en los aspectos inmune-inflamatorios de esta enfermedad. Este estudio analiza los cambios en las subpoblaciones de linfocitos T y en los mediadores inflamatorios (como IL-6, IL-10 y TNF-alpha) en CMSP de pacientes con ICE después del tratamiento con CMM-CU y estudia la correlación entre mediadores inflamatorios y células progenitoras endoteliales (CPE). Pacientes y métodos: Ocho pacientes recibieron trasplante de CMM-CU. Se recogieron muestras de sangre periférica de 8 pacientes y 8 voluntarios sanos, antes del tratamiento, a las 24h y un mes después. Los pacientes fueron evaluados para detectar cambios en IL-6, IL-10, TNF-alpha y niveles de CPE circulantes. Resultados: Los niveles séricos de TNF-alpha e IL-6 aumentaron 24h después del tratamiento (p=0,017, p=0,099) y luego disminuyeron al mes (p=0,031, p=0,072) en comparación con los niveles antes del tratamiento. Los porcentajes de CD3+T, CD3+CD4+ linfocitos T y células NK disminuyeron significativamente después del tratamiento con CMM-CU (p=0,002, p=0,012 y p=0,029, respectivamente). TNF-alpha (r=−0,602, p=0,038) demostró estar correlacionada inversamente con el número de CPE circulantes. Conclusiones: Este estudio demuestra que las CMM-CU tienen propiedades antiinflamatorias e inmunomoduladoras en la ICE y sugieren que las CMM-CU promueven la curación de heridas que no cicatrizan

Effectiveness of umbilical cord mesenchymal stem cells in patients with critical limb ischemia.

INTRODUCTION AND OBJECTIVE: Transplantation of umbilical cord mesenchymal stem cells (UC-MSCs) has been shown to be effective in treating critical limb ischemia (CLI). However, the mechanism of MSCs-mediated improvements, especially on the immune-inflammatory aspects of this disease, is still unknown. In this study, we investigated the changes in T-lymphocyte subpopulations and inflammatory mediators (such as IL-6, IL-10 and TNF-α) in PBMCs from CLI patients after UC-MSCs treatment and correlation between inflammatory mediators and EPCs. PATIENTS AND METHODS: 8 patients received UC-MSCs transplantation. Before the treatment, at 24h and 1 month thereafter, peripheral blood samples were collected from 8 patients and 8 healthy volunteers. Patients were evaluated for changes in IL-6, IL-10, TNF-α and levels of circulating EPCs. RESULTS: TNF-α and IL-6 serum levels increased at 24h (p=0.017, p=0.099) after treatment and then decreased at 1 month (p=0.031, p=0.072) compared with those before treatment. The percentages of CD3+T, CD3+CD4+T-lymphocytes and NK cells decreased significantly after UC-MSCs treatment (p=0.002, p=0.012 and p=0.029, respectively). TNF-α (r=-0.602, p=0.038) was shown to be inversely correlated with the number of circulating EPCs. CONCLUSIONS: This study demonstrates that UC-MSCs have anti-inflammatory and immunomodulation properties in CLI and suggests that UC-MSCs promote healing of non-healing wounds.

[Effect of drought stress on growth and physiological-biochemical characteristics of Stellaria dichotoma].

A pot experiment was conducted to study effect of drought stress on leaf physiological characteristics and growth of one year old Stellaria dichotoma seedlings. The result showed that plant height and shoot dry weight significantly decreased with decrease in soil water content; however, root length and root dry weight increased at light drought stress and decreased at severe drought stress. The result also showed that with the decrease of soil water content, proline content in S. dichotoma leaves decreased then increase, while solube protein content decreased. Activities of SOD and POD in S. dichotoma leaves significantly decreased as soil water content decreased, while activity of CAT significantly decreased at severe drought stress. Membrane permeability in S. dichotoma leaves increased, while MDA content decreased then increased as soil water decreased. These results suggest that S. dichotoma had osmotic stress resistance ability and reactive oxygen scavenging capacity at light drought stress, which caused S. dichotoma growth was no inhibited at a certain extent drought stress.