Wireless, battery-free and wearable device for electrically controlled drug delivery: sodium salicylate released from bilayer polypyrrole by near-field communication on smartphone.

Compared with traditional drug delivery methods, transdermal drug delivery has many advantages in avoiding the side effects in gastrointestinal tract, reducing the fluctuations in drug concentration, and improving patients' compliance. Among them, electrically controlled drug delivery is a promising solution. This work presents a wireless, battery-free and wearable device with electrically controlled drug delivery capability. The electronic component of the device is a flexible circuit board with a temperature sensor and a near-field communication module. With the help of smartphone, the device could wirelessly obtain energy and implement data transmission. The drug delivery component is a paper-based electrode modified with polypyrrole, in which non-steroidal anti-inflammatory drug sodium salicylate was encapsulated. The applied potential for electrically controlled drug delivery was more negative than -0.6 V. The drug release dose and release rates could be controlled by applying potentials with different amplitudes and durations through this device. It provided a minimalized wearable transdermal drug delivery platform for monitoring diseases such as gout. This wearable device shows promising potential in develop closed-loop drug delivery and monitoring systems for the treatment of various diseases.

Superior Antifouling Capability of Hydrogel Forward Osmosis Membrane for Treating Wastewaters with High Concentration of Organic Foulants.

Wastewaters with high concentrations of organic pollutants pose a great challenge for membrane filtration due to their severe fouling propensity. In this study, a hydrogel forward osmosis (FO) membrane is explored for treating wastewaters of high concentration organic pollutants. This FO membrane has an ultrathin hydrogel selective layer, which is highly hydrophilic (water contact angle as low as 18°) and smooth (surface roughness <5 nm). Investigated with typical organic foulants (protein, alginate, humic acid, and oil) of high concentration (2000-20 000 mg/L), this hydrogel FO membrane exhibits remarkably superior antifouling capability, with its water flux decline ratio lower than a quarter that of commercial FO membrane under identical experimental conditions. The foulants on hydrogel membrane surface can be easily removed by simple physical cleaning without any chemical usage. At the same time, this hydrogel FO membrane achieves ∼2 times higher separation efficiency than commercial FO membrane in terms of specific water flux (JW/JS). The antifouling capability and separation efficiency of this FO membrane can be flexibly tailored during selective layer fabrication process. This study opens a new avenue for the treatment of high-strength organic wastewaters by developing a highly antifouling hydrogel-based FO membrane.

Single-Walled Carbon Nanotube Film Supported Nanofiltration Membrane with a Nearly 10 nm Thick Polyamide Selective Layer for High-Flux and High-Rejection Desalination.

Fabricating nanofiltration (NF) membranes with high permeating flux and simultaneous high rejection rate for desalination is rather significant and highly desired. A new avenue is reported in this work to design NF membrane by using polydopamine wrapped single-walled carbon nanotube (PD/SWCNTs) ultrathin film as support layer instead of the use of traditional polymer-based underlying layers. Thanks to the high porosity, smooth surface, and more importantly optimal hydrophilic surface of PD/SWCNTs film, a defect-free polyamide selective layer for NF membrane with thickness of as thin as 12 nm is achieved. The obtained NF membrane exhibits an extremely high performance with a permeating flux of 32 L m-2 h-1 bar-1 and a rejection rate of 95.9% to divalent ions. This value is two to five times higher than the traditional NF membranes with similar rejection rate.

Osr2 acts downstream of Pax9 and interacts with both Msx1 and Pax9 to pattern the tooth developmental field.

Mammalian tooth development depends on activation of odontogenic potential in the presumptive dental mesenchyme by the Msx1 and Pax9 transcription factors. We recently reported that the zinc finger transcription factor Osr2 was expressed in a lingual-to-buccal gradient pattern surrounding the developing mouse molar tooth germs and mice lacking Osr2 developed supernumerary teeth lingual to their molars. We report here generation of a gene-targeted mouse strain that allows conditional inactivation of Pax9 and subsequent activation of expression of Osr2 in the developing tooth mesenchyme from the Pax9 locus. Expression of Osr2 from one copy of the Pax9 gene did not disrupt normal tooth development but was sufficient to suppress supernumerary tooth formation in the Osr2(-/-) mutant mice. We found that endogenous Osr2 mRNA expression was significantly downregulated in the developing tooth mesenchyme in Pax9(del/del) mice. Mice lacking both Osr2 and Pax9 exhibited early tooth developmental arrest with significantly reduced Bmp4 and Msx1 mRNA expression in the developing tooth mesenchyme, similar to that in Pax9(del/del) mutants but in contrast to the rescue of tooth morphogenesis in Msx1(-/-)Osr2(-/-) double mutant mice. Furthermore, we found that Osr2 formed stable protein complexes with the Msx1 protein and interacted weakly with the Pax9 protein in co-transfected cells. These data indicate that Osr2 acts downstream of Pax9 and patterns the mesenchymal odontogenic field through protein-protein interactions with Msx1 and Pax9 during early tooth development.

Therapeutic effectiveness of slow-release PLGA-oxaliplatin microsphere on human colorectal tumor-bearing mice.

The aim was to develop a slow-release poly-lactic-coglycolic acid (PLGA)-oxaliplatin microsphere and to assess the therapeutic effectiveness and safety of this preparation on colorectal tumor in vivo. The PLGA-oxaliplatin microsphere was prepared based on a spray-drying method, and the drug loading and in-vitro oxaliplatin release profile were carried out using high performance liquid chromatography. The inhibiting effect on tumor growth was examined using in-vivo subcutaneously inoculated colorectal tumor models of nude mice. The size of the microsphere was less than 100 microm, drug loading was 18-22% and drug release time lasted as long as 30 days. PLGA-oxaliplatin microspheres significantly restrained tumor growth and this effect correlated with decreased expression of proliferating cell nuclear antigen and increased expression of terminal deoxynucleotidyltransferase dUTP nick end labeling in tumor cells. Bodyweight measurement and blood analysis did not suggest significant adverse effects on the mice during the study. The PLGA-oxaliplatin microsphere developed here was suitable for regional use; it appears safe and effective in controlling the tumor growth. This preparation shows promise in reducing local recurrence of colorectal cancer after resection, but needs further investigation.

Effect of concentration of PEG coated gold nanoparticle on lung surfactant studied with coarse-grained molecular dynamics simulations.

The surface modification of nanoparticles can not only change the physical and chemical properties of particles, such as the hydrophilic and hydrophobic properties and surface charges of nanoparticles to a certain extent, but also bring new functions to nanoparticles, such as membrane permeability and targeting. Inhaled nanoparticles (NPs) are experienced by the first biological barrier inside the alveolus known as lung surfactant (LS), consisting of phospholipids and proteins in the form of the monolayer at the air-water interface. Inhaled NPs can reach deep into the lungs and interfere with the biophysical properties of the lung components. The interaction mechanisms of bare gold nanoparticles (AuNPs) with the LS monolayer are not well understood. Coarse-grained molecular dynamics simulations were carried out to have a study on the interactions of PEG coated AuNPs with LS monolayers. It was observed that the interactions of AuNPs and LS components make the monolayer structure deform and change the biophysical properties of LS monolayer. The results also indicate that AuNPs with high concentrations hinder the lowering of the LS surface tension and reduce lateral mobility of lipids. Overall, the simulation results can provide guidance for the design of ligand protected NPs as drug carriers and can identify the nanoparticles potential side effect on lung surfactant.

A new nano-engineered hierarchical membrane for concurrent removal of surfactant and oil from oil-in-water nanoemulsion.

Surfactant stabilized oil-in-water nanoemulsions pose a severe threat to both the environment and human health. Recent development of membrane filtration technology has enabled efficient oil removal from oil/water nanoemulsion, however, the concurrent removal of surfactant and oil remains unsolved because the existing filtration membranes still suffer from low surfactant removal rate and serious surfactant-induced fouling issue. In this study, to realize the concurrent removal of surfactant and oil from nanoemulsion, a novel hierarchically-structured membrane is designed with a nanostructured selective layer on top of a microstructured support layer. The physical and chemical properties of the overall membrane, including wettability, surface roughness, electric charge, thickness and structures, are delicately tailored through a nano-engineered fabrication process, that is, graphene oxide (GO) nanosheet assisted phase inversion coupled with surface functionalization. Compared with the membrane fabricated by conventional phase inversion, this novel membrane has four times higher water flux, significantly higher rejections of both oil (~99.9%) and surfactant (as high as 93.5%), and two thirds lower fouling ratio when treating surfactant stabilized oil-in-water nanoemulsion. Due to its excellent performances and facile fabrication process, this nano-engineered membrane is expected to have wide practical applications in the oil/water separation fields of environmental protection and water purification.

A new nanocomposite forward osmosis membrane custom-designed for treating shale gas wastewater.

Managing the wastewater discharged from oil and shale gas fields is a big challenge, because this kind of wastewater is normally polluted by high contents of both oils and salts. Conventional pressure-driven membranes experience little success for treating this wastewater because of either severe membrane fouling or incapability of desalination. In this study, we designed a new nanocomposite forward osmosis (FO) membrane for accomplishing simultaneous oil/water separation and desalination. This nanocomposite FO membrane is composed of an oil-repelling and salt-rejecting hydrogel selective layer on top of a graphene oxide (GO) nanosheets infused polymeric support layer. The hydrogel selective layer demonstrates strong underwater oleophobicity that leads to superior anti-fouling capability under various oil/water emulsions, and the infused GO in support layer can significantly mitigate internal concentration polarization (ICP) through reducing FO membrane structural parameter by as much as 20%. Compared with commercial FO membrane, this new FO membrane demonstrates more than three times higher water flux, higher removals for oil and salts (>99.9% for oil and >99.7% for multivalent ions) and significantly lower fouling tendency when investigated with simulated shale gas wastewater. These combined merits will endorse this new FO membrane with wide applications in treating highly saline and oily wastewaters.

Hierarchical 3D dendritic TiO2 nanospheres building with ultralong 1D nanoribbon/wires for high performance concurrent photocatalytic membrane water purification.

Hierarchical 3D dendritic TiO2 nanospheres building with ultralong 1D TiO2 nanoribbon/wires were hydrothermally synthesized via controlling the hydrolysis rate of precursor by EG. It is found that the EG and Cl(-) in the precursor solution are the dominant factors in controlling the hydrolysis rate of Ti(4+) from TTIP, and the growing direction of 1D TiO2, respectively. Through optimizing the molar ratio of TTIP:EG, hierarchical 3D dendritic TiO2 nanospheres building with long 1D nanoribbons (TiO2 nanoribbon spheres) were synthesized at a molar ratio of TTIP:EG = 1:2. And hierarchical 3D dendritic TiO2 nanospheres building with even longer and thinner 1D TiO2 nanowires (TiO2 nanowire spheres) were synthesized via further reducing the hydrolysis rate of Ti(4+) by increasing the content of EG at a molar ratio of TTIP:EG = 1:3. The hierarchical 3D dendritic TiO2 nanoribbon/wire spheres were well characterized by a variety of techniques such as FESEM, TEM, XRD, N2 adsorption/desorption, UV-vis spectra, etc. A "win-win" strategy was developed to integrate the hierarchical TiO2 nanoribbon/wire spheres and membrane for high performance photocatalytic membrane water purification through maximizing the advantages of TiO2 photocatalysis and membrane, while minimizing their disadvantages. Hierarchical TiO2 nanoribbon/wire spheres exhibited high performance for water purification in terms of high flux, low fouling, high removal rate of pollutants, and long lifespan of membrane, both in concurrent dead end and cross flow membrane system. The rationale behind this phenomenon lies in that the hierarchical TiO2 nanoribbon/wire spheres in the concurrent system possess the advantages of mitigating the membrane fouling via photocatalytic degrading the organic pollutants relying on their high photocatalytic activities; and keeping high water flux owing to the porous functional layer favorable for water pass through. The experimental results demonstrated that the hierarchical TiO2 nanoribbon/wire spheres have better photodegradation ability of AO 7 and RhB pollutants so as to result in higher ability in mitigating fouling, and keep higher flux than TiO2 P25 under the same conditions. It is believable that this study is of great significances both in synthesizing hierarchical 3D dendritic TiO2 nanospheres building with ultralong 1D nanoribbon/wires, and in providing a "win-win" strategy for high performance concurrent photocatalytic membrane water purification featured as high flux, high removal rate of pollutants, low fouling and long membrane lifespan.

Concurrent filtration and solar photocatalytic disinfection/degradation using high-performance Ag/TiO2 nanofiber membrane.

A facile polyol synthesis was used for the deposition of Ag nanoparticles on electrospun TiO2 nanofibers for the subsequent fabrication of Ag/TiO2 nanofiber membrane. The permeate flux of the Ag/TiO2 nanofiber membrane was remarkably high compared to commercial P25 deposited membrane. The Ag/TiO2 nanofiber membrane achieved 99.9% bacteria inactivation and 80.0% dye degradation under solar irradiation within 30 min. The Ag/TiO2 nanofiber membrane also showed excellent antibacterial capability without solar irradiation. Considering the excellent intrinsic antibacterial activity and high-performance photocatalytic disinfection/degradation under solar irradiation, this novel membrane proved to have promising applications in water purification industry.