High-Performance T1-T2 Dual-Modal MRI Contrast Agents through Interface Engineering.

Iron oxide nanoparticles (IONPs) have been developed as contrast agents for T1- or T2-weighted magnetic resonance imaging (MRI) on account of their excellent physicochemical and biological properties. However, general strategies to improve longitudinal relaxivity (r1) often decrease transverse relaxivity (r2), thus synchronously strengthening the T1 and T2 enhancement effect of IONPs remains a challenge. Here, we report interface regulation and size tailoring of a group of FePt@Fe3O4 core-shell nanoparticles (NPs), which possess high r1 and r2 relaxivities. The increase of r1 and r2 is due to the enhancement of the saturation magnetization (Ms), which is a result of the strengthened exchange coupling across the core-shell interface. In vivo subcutaneous tumor study and brain glioma imaging revealed that FePt@Fe3O4 NPs can serve as a favorable T1-T2 dual-modal contrast agent. We envision that the core-shell NPs, through interface engineering, have great potential in preclinical and clinical MRI applications.

Application of the cortical bone trajectory technique in posterior lumbar fixation.

The cortical bone trajectory (CBT) is a novel technique in lumbar fixation and fusion. The unique caudocephalad and medial-lateral screw trajectories endow it with excellent screw purchase for vertebral fixation via a minimally invasive method. The combined use of CBT screws with transforaminal or posterior lumbar interbody fusion can treat a variety of lumbar diseases, including spondylolisthesis or stenosis, and can also be used as a remedy for revision surgery when the pedicle screw fails. CBT has obvious advantages in terms of surgical trauma, postoperative recovery, prevention and treatment of adjacent vertebral disease, and the surgical treatment of obese and osteoporosis patients. However, the concept of CBT internal fixation technology appeared relatively recently; consequently, there are few relevant clinical studies, and the long-term clinical efficacy and related complications have not been reported. Therefore, large sample and prospective studies are needed to further reveal the long-term complications and fusion rate. As a supplement to the traditional pedicle trajectory fixation technique, the CBT technique is a good choice for the treatment of lumbar diseases with accurate screw placement and strict indications and is thus deserving of clinical recommendation.

Effects on biological behavior of bladder carcinoma T24 cells via silencing DNMT1 and/or DNMT3b with shRNA in vitro.

In this study, RNA interference technique was employed to silence the expression of DNMT1 and/or DNMT3b in human bladder cancer T24 cells. The expression levels of their mRNA and protein were greatly decreased by up to 75% and 65% respectively after T24 cells were transfected with lipofectamine2000 for 72 h, indicating RNA interference is an effective tool in gene knockdown. Proliferation and apoptosis of T24 cells were detected by MTT, and annexin-V-FITC and propidium iodide staining flow cytometry, respectively. It was found that loss of the DNMT1 or DNMT3b expression could inhibit the cell growth and promote the cell apoptosis to some extent. However, combined treatment with shRNA targeting both DNMT1 and DNMT3b mRNA could obviously enhance the above effects. It was concluded that simultaneously silencing both genes could result in strong suppressing effect on tumor proliferation and promoting cell apoptosis than separate use, suggesting combined use of DNMT1 and DNMT3b can achieve a synergistic effect in the CpG island methylation in human bladder tumorigenesis.

Effects on Biological Behavior of Bladder Carcinoma T24 Cells via Silencing DNMT1 and/or DNMT3b with shRNA In Vitro / 华中科技大学学报（医学）（英德文版）

In this study,RNA interference technique was employed to silence the expression of DNMT1 and/or DNMT3b in human bladder cancer T24 cells.The expression levels of their mRNA and protein were greatly decreased by up to 75% and 65% respectively after T24 cells were transfected with lipofectamine2000 for 72 h,indicating RNA interference is an effective tool in gene knockdown.Proliferation and apoptosis of T24 cells were detected by MTT,and annexin-V-FITC and propidium iodide staining flow cytometry,respectively.It was found that loss of the DNMT1 or DNMT3b expression could inhibit the cell growth and promote the cell apoptosis to some extent.However,combined treatment with shRNA targeting both DNMT1 and DNMT3b mRNA could ob-viously enhance the above effects.It was concluded that simultaneously silencing both genes could result in strong suppressing effect on tumor proliferation and promoting ceil apoptosis than separate use,suggesting combined use of DNMT1 and DNMT3b can achieve a synergistic effect in the CpG island methylation in human bladder tumorigenesis.