Rational Design of High-Flux, Eco-Friendly, and Versatile Superhydrophobic/Superoleophilic PDMS@ZIF-7/Cu3(PO4)2 Mesh with Self-Cleaning Property for Oil-Water Mixture and Emulsion Separation.

In recent years, efficient oil-water separation has gradually become an indispensable part of environmental treatment. Superhydrophobic/superoleophilic materials with excellent self-cleaning performance are urgently required and remain challenging in the investigation of practical, rapid, and efficient separation of oil-water mixture and emulsion, especially those with robust surfaces that can be used in harsh conditions. In this work, a novel superhydrophobic/superoleophilic material was first fabricated by in situ constructing PDMS@ZIF-7/Cu3(PO4)2 hierarchical architectures on a copper mesh, which was adopted as a high flux and efficient separation material for gravity-driven separation of oil-water mixture as well as emulsion. The introduction of crucial Cu3(PO4)2 nanosheet interlayers created the ideal hierarchical structures and serve as partial templates for the subsequent in situ growth of hydrophobic ZIF-7 nanosheets. An improved superhydrophobicity (CA = 155°), permeation flux (102,000 L m-2 h-1), and preferred self-cleaning property were thus achieved by such manipulation of the copper mesh. The PDMS@ZIF-7/Cu3(PO4)2 mesh exhibited exceptional separation efficiency for diverse oil-water mixtures and emulsions attributed to the superhydrophobicity and the demulsification ability and considerable stability to cope with extreme environments including sunlight resistance, low temperature, and corrosion resistance, which prompted its promising applicability in cleaning emulsified wastewater.

Expression of group II metabotropic glutamate receptors in rat superior cervical ganglion.

BACKGROUND: The superior cervical ganglion (SCG) plays critical roles in the regulation of blood pressure and cardiac output. Metabotropic glutamate receptors (mGluRs) in the SCG are not clearly elucidated yet. Most studies on the expression and functions of mGluRs in the SCG focused on the cultured SCG neurons, and yet little information has been reported in the SCG tissue. Chronic intermittent hypoxia (CIH), one of the major clinical features of obstructive sleep apnea (OSA) patients, is a critical pathological cause of secondary hypertension in OSA patients, but its impact on the level of mGluRs in the SCG is unknown. OBJECTIVE: To explore the expression and localization of mGluR2/3 and the effect of CIH on mGluR2/3 level in rat SCG tissue. METHODS: RT-PCR and immunostaining were conducted to examine the mRNA and protein expression of mGluR2/3 in rat SCG. Immunofluorescence staining was conducted to examine the distribution of mGluR2/3. Rats were divided into control and CIH group which the rats were exposed to CIH for 6 weeks. Western blots were performed to examine the level of mGluR2/3 in rat SCG. RESULTS: mRNAs of mGluR2/3 expressed in rat SCG. mGluR2 distributed in principal neurons and small intensely fluorescent cells but not in satellite glial cells, nerve fibers, and vascular endothelial cells; mGluR3 was detected in nerve fibers rather than in the cells mentioned above. CIH exposure reduced the protein level of mGluR2/3 in rat SCG. CONCLUSION: mGluR2/3 exists in rat SCG with diverse distribution patterns, and may be involved in CIH-induced hypertension.

Ultrasound-triggered drug delivery for glioma therapy through gambogic acid-loaded nanobubble-microbubble complexes.

Glioma is one of the most common primary brain tumors. Gambogic acid (GA) is widely used in tumor chemotherapy. However, GA has poor water solubility, low bioavailability, and difficult permeability across the blood-brain barrier (BBB), leading to poor efficacy against brain tumors. In our study, we developed negatively charged GA-loaded PLGA nanobubbles [GA/poly(lactic-co-glycolic acid) (PLGA)] and conjugated them onto the surface of cationic lipid microbubbles (CMBs) through electrostatic interactions. The resulting GA/PLGA-CMB complex was characterized for its particle size, distribution, drug encapsulation efficiency, and ultrasound imaging property, revealing a high drug encapsulation efficiency and excellent contrast imaging capability. Importantly, significantly enhanced GA delivery into the brain could be observed after the intravenous administration of GA/PLGA-CMBs combined with low-intensity focused ultrasound (FUS) due to the cavitation from CMBs, which mediated blood-brain barrier (BBB) opening. Taking advantage of the opened BBB, GA/PLGA nanobubbles could be delivered into the tumor. Then, the second FUS irradiation at higher energy was used to induce the cavitation of GA/PLGA nanobubbles, producing the second cavitation on tumor cells, significantly enhancing the ability of GA to enter tumor cells and inhibit tumor growth inhibition efficacy.

A Gambogic Acid-Loaded Delivery System Mediated by Ultrasound-Targeted Microbubble Destruction: A Promising Therapy Method for Malignant Cerebral Glioma.

Background: The blood-brain barrier (BBB) inhibits the delivery of macromolecular chemotherapeutic drugs to brain tumors, leading to low utilization rates and toxic side effects to surrounding tissues and organs. Ultrasonic targeted microbubble destruction (UTMD) technology can open the BBB, leading to a new type of drug delivery system with particular utility in glioma. Purpose: We have developed a new type of drug-loaded microbubble complex based on poly(lactic-co-glycolic acid) (PLGA) that targets gambogic acid (GA) to the area of brain tumors through UTMD. Methods: GA/PLGA nanoparticles were prepared by the double emulsification method, and cationic microbubbles (CMBs) were prepared by a thin film hydration method. The GA/PLGA-CMB microbubble complex was assembled through electrostatic attractions and was characterized chemically. The anti-glioblastoma effect of GA/PLGA-CMB combined with focused ultrasound (FUS) was evaluated by biochemical and imaging assays in cultured cells and model mice. Results: GA/PLGA-CMB combined with FUS demonstrated a significant inhibitory effect on glioblastoma cell lines U87 and U251 as compared with controls (P<0.05). Tumor access and imaging analyses demonstrated that administration of GA/PLGA-CMBs combined with FUS can open the BBB and target the treatment of glioblastoma in a mouse model, as compared with control groups (P<0.05). Conclusion: The combination of PLGA-CMB with FUS provides an effective and biocompatible drug delivery system, and its application to the delivery of GA in a mouse glioblastoma model was successful.

Effect of Gambogic Acid-Loaded Porous-Lipid/PLGA Microbubbles in Combination With Ultrasound-Triggered Microbubble Destruction on Human Glioma.

Gambogic acid (GA) is a highly effective antitumor agent, and it is used for the treatment of a wide range of cancers. It is challenging to deliver drugs to the central nervous system due to the inability of GA to cross the blood-brain barrier (BBB). Studies have shown that ultrasound-targeted microbubble destruction can be used for transient and reversible BBB disruption, significantly facilitating intracerebral drug delivery. We first prepared GA-loaded porous-lipid microbubbles (GA porous-lipid/PLGA MBs), and an in vitro BBB model was established. The cell viability was detected by CCK-8 assay and flow cytometry. The results indicate that U251 human glioma cells were killed by focused ultrasound (FUS) combined with GA/PLGA microbubbles. FUS combined with GA/PLGA microbubbles was capable of locally and transiently enhancing the permeability of BBB under certain conditions. This conformational change allows the release of GA to extracellular space. This study provides novel targets for the treatment of glioma.

Ultrasound Combined With Microbubbles Loading BDNF Retrovirus to Open BloodBrain Barrier for Treatment of Alzheimer's Disease.

Background: Brain-derived nerve growth factor (BDNF) is a promising effective target for the treatment of Alzheimer's disease (AD). BDNF, which has a high molecular weight, has difficulty in crossing the blood-brain barrier (BBB). The study aimed to prepare microbubbles loading brain-derived nerve growth factor (BDNF) retrovirus (MpLXSN-BDNF), to verify the characteristics of the microbubbles, and to study the therapeutic effect of the microbubbles combined with ultrasound on the opening of the blood-brain barrier in an AD rat model. Methods: 32 adult male SD rats were randomly divided into four groups: control group, ultrasound + pLXSN-EGFP microbubble group (U + MpLXSN-BDNF), ultrasound + pLXSN-BDNF microbubble group, and ultrasound + microbubble + pLXSN-BDNF virus group (U + MpLXSN-BDNF), with eight rats in each group. At the same time, the left hippocampus of rats was irradiated with low-frequency focused ultrasound guided by MRI to open the blood-brain barrier (BBB). The effects of BDNF overexpression on AD rats were evaluated behaviorally before and 1 month after the treatment. The number of acetylcholinesterase (ChAT)-positive cells and the content of acetylcholine (ACh) in brain tissues were determined by immunohistochemistry and high-performance liquid chromatography (HPLC), respectively. IF staining of synaptic spines and Western blot of synaptophysin presented herein detected synaptic density recovery. Results: Signal intensity enhancement at the BBB disruption sites could be observed on the MR images. The behavioral evaluation showed that the times of crossing the original platform in the U + MpLXSN-BDNF group increased significantly after treatment. Immunohistochemistry and HPLC revealed that the number of ChAT-positive neurons and the contents of ACh in the brain were significantly decreased in the treated groups compared with the controls. IF staining of synaptic spines and Western blot data of synaptophysin showed that the U + MpLXSN-BDNF group can recover the synaptic loss better by BDNF supplementation than the other treatment groups. Conclusion: Ultrasound combined with viral microbubbles carrying BDNF can increase the transfection efficiency of brain neurons, promote the high expression of exogenous gene BDNF, and play a therapeutic role in the AD model rats.

MRI-Guided Focused Ultrasound-Induced Blood Brain Barrier Disruption to Deliver Glial Cell Line Derived Neurotropic Factor Proteins into Brain to Treat Rat Depression.

Glial cell line derived neurotropic factor (GDNF) plays a crucial role in the development and maintenance of glial cells, serotonergic and dopaminergic neurons. A positively therapeutic effect has been demonstrated on some animal neurodegenerative diseases. However, the inability to deliver the protein across blood brain barrier (BBB) into damaged brain region limits its clinical application. Here, we developed GDNF-loaded microbubbles (MBs) and achieved a local and precise delivery of GDNF into the brain through MRI-guided focused ultrasound-induced BBB disruption. To demonstrate the therapeutic effect, rat depression model was developed by chronic mild stress treatment. Typical depression behaviors were confirmed. MRI-guided focused ultrasound was used to irradiate the GDNF-loaded MBs. Obvious BBB opening was observed in the treated rat brains and a significant higher GDNF concentration was detected in the ultrasound-treated brain tissues. Behavioral tests demonstrated the increased GDNF could reverse the depressive-like behaviors induced by chronic mild stress, improve the expression of 5-HT 1B receptor and the protein p11, and increase the number of 5-HT or TPH2 immunoreactive neurons. In conclusion, our study provided an effective approach to deliver GDNF proteins into brain to treat rat depression through MRI-guided focused ultrasound-induced destruction of blood-brain barrier.

ADAPT identifies an ESCRT complex composition that discriminates VCaP from LNCaP prostate cancer cell exosomes.

Libraries of single-stranded oligodeoxynucleotides (ssODNs) can be enriched for sequences that specifically bind molecules on naïve complex biological samples like cells or tissues. Depending on the enrichment strategy, the ssODNs can identify molecules specifically associated with a defined biological condition, for example a pathological phenotype, and thus are potentially useful for biomarker discovery. We performed ADAPT, a variant of SELEX, on exosomes secreted by VCaP prostate cancer cells. A library of ∼1011 ssODNs was enriched for those that bind to VCaP exosomes and discriminate them from exosomes derived from LNCaP prostate cancer cells. Next-generation sequencing (NGS) identified the best discriminating ssODNs, nine of which were resynthesized and their discriminatory ability confirmed by qPCR. Affinity purification with one of the sequences (Sequence 7) combined with LC-MS/MS identified its molecular target complex, whereof most proteins are part of or associated with the multiprotein ESCRT complex participating in exosome biogenesis. Within this complex, YBX1 was identified as the directly-bound target protein. ADAPT thus is able to differentiate exosomes from cancer cell subtypes from the same lineage. The composition of ESCRT complexes in exosomes from VCaP versus LNCaP cells might constitute a discriminatory element between these prostate cancer subtypes.

Development of an innovative capsule with three-dimension honeycomb architecture via one-step titration-gel method for the removal of methylene blue.

In this study, the capsules were prepared via the one-step titration-gel method by injecting spherical droplets of polyvinyl alcohol (PVA), sodium alginate (SA) and graphene oxide (GO) gelled mixture into the bath with calcium chloride (CaCl2) and oversaturated boric acid (H3BO3) solutions. The prepared capsules were then further modified with glutaraldehyde (GA). The formation mechanism of the prepared capsules was investigated. The morphology of the prepared capsules exhibited distinct micro-porous "3D honeycomb" pattern and hierarchical pore sizes distribution. It was also observed that GA not only acted as a co-cross-linked reagent in the fabricating process to increase the specific surface area of the capsules, but also offered exceptional tolerance property to work under a wide pH range (i.e. 2-12). The PVA-SA-GO capsules performed comparatively much better than PVA-SA capsules and they improved the adsorption capacity by up to 21.94%. Their adsorptive performance well followed the Langmuir isotherm. Moreover, the pH of the MB solution was evidently declined after adsorption, demonstrating the electrostatic attraction or ion-exchange might be the governing removal mechanism of methylene blue (MB) dye by the capsules. Importantly, the prepared capsules could be regenerated by simply washing with water and reused for at least 6 consecutive treatment cycles.

Poly-ligand profiling differentiates trastuzumab-treated breast cancer patients according to their outcomes.

Assessing the phenotypic diversity underlying tumour progression requires the identification of variations in the respective molecular interaction networks. Here we report proof-of-concept for a platform called poly-ligand profiling (PLP) that surveys these system states and distinguishes breast cancer patients who did or did not derive benefit from trastuzumab. We perform tissue-SELEX on breast cancer specimens to enrich single-stranded DNA (ssDNA) libraries that preferentially interact with molecular components associated with the two clinical phenotypes. Testing of independent sample sets verifies the ability of PLP to classify trastuzumab-treated patients according to their clinical outcomes with ROC-AUC of 0.78. Standard HER2 testing of the same patients gives a ROC-AUC of 0.47. Kaplan-Meier analysis reveals a median increase in benefit from trastuzumab-containing treatments of 300 days for PLP-positive compared to PLP-negative patients. If prospectively validated, PLP may increase success rates in precision oncology and clinical trials, thus improving both patient care and drug development.

Plasma Exosome Profiling of Cancer Patients by a Next Generation Systems Biology Approach.

Technologies capable of characterizing the full breadth of cellular systems need to be able to measure millions of proteins, isoforms, and complexes simultaneously. We describe an approach that fulfils this criterion: Adaptive Dynamic Artificial Poly-ligand Targeting (ADAPT). ADAPT employs an enriched library of single-stranded oligodeoxynucleotides (ssODNs) to profile complex biological samples, thus achieving an unprecedented coverage of system-wide, native biomolecules. We used ADAPT as a highly specific profiling tool that distinguishes women with or without breast cancer based on circulating exosomes in their blood. To develop ADAPT, we enriched a library of ~1011 ssODNs for those associating with exosomes from breast cancer patients or controls. The resulting 106 enriched ssODNs were then profiled against plasma from independent groups of healthy and breast cancer-positive women. ssODN-mediated affinity purification and mass spectrometry identified low-abundance exosome-associated proteins and protein complexes, some with known significance in both normal homeostasis and disease. Sequencing of the recovered ssODNs provided quantitative measures that were used to build highly accurate multi-analyte signatures for patient classification. Probing plasma from 500 subjects with a smaller subset of 2000 resynthesized ssODNs stratified healthy, breast biopsy-negative, and -positive women. An AUC of 0.73 was obtained when comparing healthy donors with biopsy-positive patients.

Cuboid Vesicles Formed by Frame-Guided Assembly on DNA Origami Scaffolds.

We describe the use of a frame-guided assembly (FGA) strategy to construct cuboid and dumbbell-shaped hetero-vesicles on DNA origami nanostructure scaffolds. These are achieved by varying the design of the DNA origami scaffolds that direct the distribution of the leading hydrophobic groups (LHG). By careful selection of LHGs, different types of amphiphiles (both polymer and small-molecule surfactants) were guided to form hetero-vesicles, demonstrating the versatility of the FGA strategy and its potential to construct asymmetric and dynamic hetero-vesicle assemblies with complex DNA nano-scaffolds.

Uncovering the self-assembly of DNA nanostructures by thermodynamics and kinetics.

CONSPECTUS: DNA nanotechnology is one of the most flourishing interdisciplinary research fields. DNA nanostructures can be designed to self-assemble into a variety of periodic or aperiodic patterns of different shapes and length scales. They can be used as scaffolds for organizing other nanoparticles, proteins, and chemical groups, leveraging their functions for creating complex bioinspired materials that may serve as smart drug delivery systems, in vitro or in vivo biomolecular computing platforms, and diagnostic devices. Achieving optimal structural features, efficient assembly protocols, and precise functional group positioning and modification requires a thorough understanding of the thermodynamics and kinetics of the DNA nanostructure self-assembly process. The most common real-time measurement strategies include monitoring changes in UV absorbance based on the hyperchromic effect of DNA, and the emission signal changes of DNA intercalating dyes or covalently conjugated fluorescent dyes/pairs that accompany temperature dependent structural changes. Thermodynamic studies of a variety of DNA nanostructures have been performed, from simple double stranded DNA formation to more complex origami assembly. The key parameters that have been evaluated in terms of stability and cooperativity include the overall dimensions, the folding path of the scaffold, crossover and nick point arrangement, length and sequence of single strands, and salt and ion concentrations. DNA tile-tile interactions through sticky end hybridization have also been analyzed, and the steric inhibition and rigidity of tiles turn out to be important factors. Many kinetic studies have also been reported, and most are based on double stranded DNA formation. A two-state assumption and the hypothesis of several intermediate states have been applied to determine the rate constant and activation energy of the DNA hybridization process. A few simulated models were proposed to represent the structural, mechanical, and kinetic properties of DNA hybridization. The kinetics of strand displacement reactions has also been studied as a special case of DNA hybridization. The thermodynamic and kinetic characteristics of DNA nanostructures have been exploited to develop rapid and isothermal annealing protocols. It is conceivable that a more thorough understanding of the DNA assembly process could be used to guide the structural design process and optimize the conditions for assembly, manipulation, and functionalization, thus benefiting both upstream design and downstream applications.

Mapping the thermal behavior of DNA origami nanostructures.

Understanding the thermodynamic properties of complex DNA nanostructures, including rationally designed two- and three-dimensional (2D and 3D, respectively) DNA origami, facilitates more accurate spatiotemporal control and effective functionalization of the structures by other elements. In this work fluorescein and tetramethylrhodamine (TAMRA), a Förster resonance energy transfer (FRET) dye pair, were incorporated into selected staples within various 2D and 3D DNA origami structures. We monitored the temperature-dependent changes in FRET efficiency that occurred as the dye-labeled structures were annealed and melted and subsequently extracted information about the associative and dissociative behavior of the origami. In particular, we examined the effects of local and long-range structural defects (omitted staple strands) on the thermal stability of common DNA origami structures. The results revealed a significant decrease in thermal stability of the structures in the vicinity of the defects, in contrast to the negligible long-range effects that were observed. Furthermore, we probed the global assembly and disassembly processes by comparing the thermal behavior of the FRET pair at several different positions. We demonstrated that the staple strands located in different areas of the structure all exhibit highly cooperative hybridization but have distinguishable melting temperatures depending on their positions. This work underscores the importance of understanding fundamental aspects of the self-assembly of DNA nanostructures and can be used to guide the design of more complicated DNA nanostructures, to optimize annealing protocol and manipulate functionalized DNA nanostructures.

Size-selective incorporation of DNA nanocages into nanoporous antimony-doped tin oxide materials.

A conductive nanoporous antimony-doped tin oxide (ATO) powder has been prepared using the sol-gel method that contains three-dimensionally interconnected pores within the metal oxide and highly tunable pore sizes on the nanoscale. It is demonstrated that these porous materials possess the capability of hosting a tetrahedral-shaped DNA nanostructure of defined dimensions with high affinity. The tunability of pore size enables the porous substrate to selectively absorb the DNA nanostructures into the metal oxide cavities or exclude them from entering the surface layer. Both confocal fluorescence microscopy and solution FRET experiments revealed that the DNA nanostructures maintained their integrity upon the size-selective incorporation into the cavities of the porous materials. As DNA nanostructures can serve as a stable three-dimensional nanoscaffold for the coordination of electron transfer mediators, this work opens up new possibilities of incorporating functionalized DNA architectures as guest molecules to nanoporous conductive metal oxides for applications such as photovoltaics, sensors, and solar fuel cells.

Stability of DNA origami nanoarrays in cell lysate.

Scaffolded DNA origami, a method to create self-assembled nanostructures with spatially addressable features, has recently been used to develop water-soluble molecular chips for label-free RNA detection, platforms for deterministic protein positioning, and single molecule reaction observatories. These applications highlight the possibility of exploiting the unique properties and biocompatibility of DNA nanostructures in live, cellular systems. Herein, we assembled several DNA origami nanostructures of differing shape, size and probes, and investigated their interaction with lysate obtained from various normal and cancerous cell lines. We separated and analyzed the origami-lysate mixtures using agarose gel electrophoresis and recovered the DNA structures for functional assay and subsequent microscopic examination. Our results demonstrate that DNA origami nanostructures are stable in cell lysate and can be easily separated from lysate mixtures, in contrast to natural, single- and double-stranded DNA. Atomic force microscope (AFM) and transmission electron microscope (TEM) images show that the DNA origami structures are fully intact after separation from cell lysates and hybridize to their targets, verifying the superior structural integrity and functionality of self-assembled DNA origami nanostructures relative to conventional oligonucleotides. The stability and functionality of DNA origami structures in cell lysate validate their use for biological applications, for example, as programmable molecular rafts or disease detection platforms.

Aqueous synthesis of zinc blende CdTe/CdS magic-core/thick-shell tetrahedral-shaped nanocrystals with emission tunable to near-infrared.

We demonstrate the synthesis of near-IR-emitting zinc blende CdTe/CdS tetrahedral-shaped nanocrystals with a magic-sized (approximately 0.8 nm radius) CdTe core and a thick CdS shell (up to 5 nm). These high-quality water-soluble nanocrystals were obtained by a simple but reliable aqueous method at low temperature. During the growth of the shell over the magic core, the core/shell nanocrystals change from type I to type II, as revealed by their enormous photoluminescence (PL) emission peak shift (from 480 to 820 nm) and significant increase in PL lifetime (from approximately 1 to approximately 245 ns). These thick-shell nanocrystals have a high PL quantum yield, high photostability, compact size (hydrodynamic diameter less than 11.0 nm), and reduced blinking behavior. The magic-core/thick-shell nanocrystals may represent an important step toward the synthesis and application of next-generation colloidal nanocrystals from solar cell conversion to intracellular imaging.