[Modified Biochar for Remediation of Soil Contaminated with Arsenic and Cadmium: A Review].

Binary pollution of arsenic (As) and cadmium (Cd) has become the main soil environmental problem in China. As an adsorbent or immobilizer, modified biochar is playing an increasing role in the remediation of As and Cd-contaminated soil. Here, the limitations regarding the primitive biochar as an immobilizer for the remediation of As and Cd-contaminated soil were highlighted by this study. Meanwhile, the biochar modification methods for the remediation of As and Cd-contaminated soil were reviewed, and the main interaction mechanisms were analyzed. Finally, the prospects and questions for the future remediation of soil contaminated with As and Cd using modified biochar were proposed. The results showed that metal-modified biochar had a better synergistic effect on the remediation of As and Cd-contaminated soil and thus had better application prospects. The immobilization mechanisms of As and Cd using biochar material remediation were affected by its modification methods. For example, the mechanisms for (non)metal-modified biochar involved the functional group-induced bonding complexation, co-precipitation, and oxyanion As redox; for microorganism-modified biochar, the mechanisms were precipitation and As redox, and those for physical- and acid-modified biochar only included the physical adsorption and weak electrostatic attraction. In view of the limitations of present research on the application of modified biochar for the remediation of As and Cd-contaminated soil, future research is suggested to study the following:① the effect of biomass feedstock type, pyrolysis temperature, preparation conditions, cost, and soil aging; ② evaluation for stability and durability of heavy metal immobilization by modified biochar remediation under different environmental factors; and ③ insight to key remediation mechanisms of As and Cd-contaminated soil by material.

[PVT1 Promoted the Proliferation and Migration Ability of BMSCs in Glioma C6 Microenvironment].

OBJECTIVE: To investigate the changes in the proliferation and migration ability of bone marrow mesenchymal stem cells (BMSCs) after indirect co-culturing with glioma C6 cells, and to examine the role of plasmacytoma variant translocation 1 gene ( PVT1), a long non-coding RNA (lncRNA), in these changes. METHODS: After separation, cultivation and identification of BMSCs, BMSCs of good growth condition were picked out and indirectly co-cultured with glioma C6 cells in Transwell chambers. These cells are henceforth referred to as the co-culture group. Normal BMSCs cultured separately were the control group. CCK-8 and soft agar colony formation assay were used to examine the proliferation ability of the two groups of cells. Flow cytometry was used to examine the cell cycle. Wound healing assay and Transwell assay were used to explore the migration ability of the cells. Quantitative real-time PCR (qRT-PCR) was used to examine the genetic expression level of PVT1 in the two groups. The above-mentioned tests were repeated after the co-cultured BMSCs were transfected with si- PVT1 (si- PVT1 group) and si-NC (si-NC group). In addition, qRT-PCR was done to evaluate the expression of CyclinD1, a cell cycle protein gene, and matrix metalloproteinases 2 and 9 ( MMP2 and MMP9), the migration-related genes in the si- PVT1 and si-NC transfected co-cultured BMSCs. RESULTS: The BMSCs used in the present study possess the capability of osteogeneic and adipogenic differentiation. Compared with the control group, the co-cultured BMSCs had smaller size, disorderly arrangement and the lack of intercellular contact inhibition. The proliferation and migration ability was significantly enhanced, the proportions of S and G 2 phase cells greatly increased and the expression level of PVT1 was significantly up-regulated ( P<0.05) in the co-cultured group in comparison with those of the control group. When compared with the si-NC group, the si- PVT1 group showed inhibited proliferation and migration ability of the co-cultured BMSCs; the percentage of G 1 phase cells increased, while that of S phase decreased; the expression of PVT1, CyclinD1, MMP2 and MMP9 mRNA also decreased ( P<0.05) in the si- PVT1 group. CONCLUSION: The enhanced proliferation and migration ability of BMSCs in the glioma C6 microenvironment may be associated with the up-regulated expression of PVT1 .