Direct Synthesis of Bienzyme-like Carbide-derived Carbons via Mild Electrochemical Oxidation of Ti 3AlC 2 MAX / 生物医学与环境科学（英文）

Objective@#To develop effective alternatives to natural enzymes, it is crucial to develop nanozymes that are economical, resource efficient, and environmentally conscious. Carbon nanomaterials that have enzyme-like activities have been extensively developed as substitutes for traditional enzymes.@*Methods@#Carbide-derived carbons (CDCs) were directly synthesized via a one-step electrochemical method from a MAX precursor using an ammonium bifluoride electrolyte at ambient conditions. The CDCs were characterized by systematic techniques.@*Results@#CDCs showed bienzyme-like activities similar to that of peroxidase and superoxide dismutase. We systematically studied the dependence of CDC enzyme-like activity on different electrolytes and electrolysis times to confirm activity dependence on CDC content. Additionally, the synthesis mechanism and CDC applicability were elaborated and demonstrated, respectively.@*Conclusion@#The demonstrated synthesis strategy eliminates tedious intercalation and delamination centrifugation steps and avoids using high concentrations of HF, high temperatures, and halogen gases. This study paves the way for designing two-dimensional material-based nanocatalysts for nanoenzyme and other applications.

Transfected thymidine phosphorylase cDNA with lentiviral vector and INF-α2a enhance the anticancer effects of 5'-deoxy-5-fluorouridine on colorectal cancer cell line LOVO / 中华普通外科杂志

Objective Thymidine phosphorylase (TP) cDNA was transfected into colorectal cancer cell lines LOVO with the lentiviral vector,the anticancer effeciency of 5'-deoxy-5-fluorouridine (5'-DFUR)and 5-fluorouracil (5-FU) on LOVO cells were evaluated.Methods TP cDNA were transfected into LOVO cell line with the lentiviral vector pLenti6.3_MCS_IRES2-EGFP,and the transfection efficiency was analyzed by flow cytometer and immunohistochemistry.Cells were divided into six groups:LOVO,LOVO-TP,LOVO-control,LOVO + INF-α2a,LOVO-TP + INF-α2a,LOVO-control + INF-α2a.TP protein expression and the relative quantitative analysis for TP mRNA in transfections cells were detected by Western blot and RT-PCR respectively.Volumes of converted 5-FU from either in the medium containing different concentration of 5'-DFUR,in which all cells were cultured,or in cells lysate,were detected by high performance liquid chromatography (HPLC).Results The transfection efficiency of TP cDNA in LOVO cells was 95％.The Mean gray value of TP protein expression in LOVO-TP and LOVO-TP + INF-α2a were 198.15 folds and 243.22 folds higher than LOVO cell,respectively (P ＜ 0.01).The RQ values of TP mRNA expression in LOVO-TP and LOVO-TP + INF-α2a were also 18.56 folds and 59.61 folds higher than wild LOVO cell,respectively (P ＜ 0.01).The IC50 values of 5'-DFUR on LOVO-TP and LOVO-TP + INF-α2a were 1 660 μ mol/L and 813 μ mol/L,respectively,significantly lower than 4 462.59 μ mol/L in wild LOVO (P ＜ O.01).The 5-FU volumes detected from media contained series concentration of 5'-DFUR for culturing LOVO-TP and LOVO-TP + INF-α2a were 2.0-5.3 folds,and 2.9-10.4 folds more than wild LOVO,respectively (P ＜ 0.01).Conclusions Transfected TP cDNA into colorectal cancer cell line LOVO with lentiviral vector increases the expression of TP mRNA and TP protein and the amount of 5-FU converted from 5'-DFUR,enhancing its anticancer effect.