A microfluidic platform utilizing anchored water-in-oil-in-water double emulsions to create a niche for analyzing single non-adherent cells.

Non-adherent cells play key roles in various biological processes. Studies on this type of cell, especially at single-cell resolution, help reveal molecular mechanisms underlying many biological and pathological processes. The emerging microfluidics technology has developed effective methods for analyzing cells. However, it remains challenging to treat and monitor single live non-adherent cells in an in situ, long-term, and real-time manner. Herein, a microfluidic platform was set up to generate and anchor cell-laden water-in-oil-in-water (W/O/W) double emulsions (DEs) to investigate these cells. Within the device, W/O/W DEs encapsulating non-adherent cells were generated through two adjacent flow-focusing structures and subsequently anchored in an array of microchambers. These droplets maintained the W/O/W structure and the anchorage status in the continuous perfusion fluid for at least one week. The mass transfer of different molecules with suitable molecular weights and partition coefficients between the interior and exterior of W/O/W DEs could be regulated by perfusion fluid flow rates. These features endow this platform with potential to continuously supply encapsulated non-adherent cells with nutrients or small-molecule stimuli/drugs through fluid perfusion. Meanwhile, the confinement of cells in the anchored DEs favored long-term monitoring of cellular dynamic behaviors and responses. As a proof of concept, fluorescein diacetate (FDA) was employed to visualize the cellular uptake and biochemical metabolism of TF-1 human erythroleukemia cells. We believe that this W/O/W DE anchorage and perfusion platform would benefit single-cell-level studies as well as small-molecule drug discovery requiring live non-adherent cells.

Suppression of TRPM7 inhibits proliferation, migration, and invasion of malignant human glioma cells.

BACKGROUND: Glioblastoma multiforme (GBM) is the most common and aggressive primary brain tumor with a dismal prognosis. Despite intensive study on tumor biology, the underlying mechanisms of the unlimited proliferation and progressive local invasion are still poorly understood, and no effective treatment has been developed for GBM patients. AIMS: We determine the role of TRPM7 channels in the growth, migration, and infiltration of malignant glioma cells. METHODS: Using a combination of RT-PCR, Western blot, and patch-clamp techniques, we demonstrated the expression of functional TRPM7 channels of A172 cells, a human glioma cell line, as well as in human glioma tissues. Furthermore, we evaluated the role of TRPM7 in growth, migration, and infiltration of A172 cells with MTT and transwell migration and invasion assays. RESULTS: We showed the expression of functional TRPM7 channels in both A172 cells and human glioma tissues. Suppression of TRPM7 expression with TRPM7-siRNA dramatically reduced the proliferation, migration, and invasion of A172 cells. Pharmacological inhibition of TRPM7 channel with 2-aminoethoxydiphenyl borate (2-APB) showed a similar effect as TRPM7-siRNA. CONCLUSION: We demonstrate that human glioma cells express functional TRPM7 channel and that activation of this channel plays an important role in the proliferation, migration, and invasion of malignant glioma cells. TRPM7 channel may represent a novel and promising target for therapeutic intervention of malignant glioma.

[Kirschner wire as blocking screws for the treatment of tibial metaphyseal fractures].

OBJECTIVE: To investigate clinical outcomes of Kirschner wire as blocking screws combined with interlocking intramedullary nail internal fixation in treating tibial metaphyseal fractures (AO 43A). METHODS: From March 2011 to June 2012, 9 patients with tibial metaphyseal fractures were treated with blocking screws Kirschner wire combined with interlocking intramedullary nail, including 7 males and 2 females aged from 23 to 54 years old with an average of 37.4. Postoperative complications, X-ray were observed, AOFAS scoring were used to evaluate function after operation at 12 weeks. RESULTS: All patients were followed up from 6 to 40 weeks (mean 20.1), and healed at stage I. No serious swelling, infection and skin necrosis occurred. No fracture instability and displacement appeaered at 4 and 8 week after operation. AOFAS score was (95.2±4.6) at 12 weeks after operation and 7 patients gained excellent result and 2 patients good. CONCLUSION: Kirschner wire as blocking screws with interlocking intramedullary nail for treatment of tibial metaphyseal fractures can fix well and perform simply.

[Ecological responses of Brassica juncea-alfalfa intercropping to cadmium stress].

A pot experiment was conducted to study the effects of cadmium (Cd) stress on the soil-plant system under Brassica juncea-alfalfa intercropping, and to evaluate the Cd feed safety of alfalfa. Comparing with monoculture, when the soil Cd content was in the range of 0.37-20.37 mg x kg(-1), intercropping decreased the B. juncea biomass by 0.4%-11.8% while increased the alfalfa biomass by 55.3%-70.0%. Soil available Cd was mainly determined by soil total Cd and plant species, and less affected by planting pattern. Comparing with monoculture, when the soil Cd content was in the range of 0.37-5.37 mg x kg(-1), intercropping increased the Cd content in above-ground part of B. juncea by 14.5%, but decreased the Cd content in above-ground part of alfalfa by 57.1%. The Cd contents in the above-ground parts of alfalfa under monoculture and intercropping were 0.21 and 0.09 mg x kg(-1), respectively, neither of them being over the feed safety standard (0.5 mg x kg(-1)). When the soil Cd content was in the range of 10.37-20.37 mg x kg(-1), though the Cd contents of mono-cultured and intercropped alfalfa were both over the standard, the Cd contents in the above-ground parts of alfalfa and B. juncea under intercropping were decreased by 2.8%-48.3% and 1.1%-48.6%, respectively. Under both monoculture and intercropping, the Cd transport coefficient of B. juncea was far greater than that of alfalfa.

Impaired reproduction in transgenic mice overexpressing Gamma-aminobutyric acid transporter I (GAT1).

It is well documented that g-aminobutyric acid (GABA) system existed in reproductive organs. Recent researches showed that GABAA and GABAB receptors were present in testis and sperm, and might mediate the acrosome reaction induced by GABA and progesterone. GABA transporter I (GAT1) also existed in testis and sperm, but its physiological function was unknown. In the present study, we used GAT1 overexpressing mice to explore GAT1 function in male reproductive system. We found that the expression level of GAT1 continuously increased in wild-type mouse testis from 1 month to 2 months after birth. GAT1 overexpression in mouse affected testis development, which embodied reduced testis mass and slowed spermatogenesis in transgenic mice. Moreover, transgenic mice showed increase of the percentage of broken sperm. The further study revealed that the reproductive capacity was impaired in GAT1 overexpressing mice. In addition, testosterone level was significantly low in transgenic mice compared with that in wild-type mice. Our findings provided the first evidence that abnormal expression of GAT1 could result in dysgenesis, and indicated that GAT1 might be therapeutically targeted for contraception or dysgenesis treatment.