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Chemotherapy is one of the most used method for cancer therapy, however, brings huge pain to patients as the drugs commonly causes side effects. Inducing tumor cells apoptosis by perturbing ion homeostasis is a novel approach to replace chemotherapy in recent years. Crown ether has been widely used since it was discovered in the last century and has shown its potential in biological applications. The aim of this paper is to design a series of novel nanometer micelles with crown ether on their surface. Crown ether was connected to a commonly used amphiphilic polymeric carrier, PEG-PCL, through ester bond (CPMs). Micelles about 120 nm in diameter were formed in aqueous solution. The micelles could capture potassium ions prominently in both aqueous solution and tumor cells. In vitro and in vivo experiments showed that the CPMs had certain anti-tumor activity, indicating that the CPMs had anti-tumor potential.

The emergence of nanomaterials for drug delivery provides the opportunity to avoid the side effects of systemic drug administration and injury caused by the removal of tumors, delivering great promise for future cancer treatments. However, the efficacy of current nano drugs is not significantly better than that of the original drug treatments. The important reason is that nano drugs enter the tumor vasculature, remaining close to the blood vessels and unable to enter the tumor tissue or tumor cells to complete the drug delivery process. The low efficiency of drug penetration into tumors has become a bottleneck restricting the development of nano-drugs. Herein, we present a systematic overview of recent advances on the design of nano-drug carriers in drug delivery systems for enhancing drug penetration into tumors. The review is organized into four sections: The drug penetration process in tumor tissue includes paracellular and transcellular transport, which is summarized first. Strategies that promote tumor penetration are then introduced, including methods of remodeling the tumor microenvironment, charge inversion, dimensional change, and surface modification of ligands which promote tissue penetration. Conclusion and the prospects for the future development of drug penetration are finally briefly illustrated. The review is intended to provide thoughts for effective treatment of cancer by summarizing strategies for promoting the endocytosis of nano drugs into tumor cells.

A promising and low-cost electrochemical sensor was carried out with carbon nanotube modified carbon-fiber electrodes via vapor deposition method, which improved the sensitivity and reduced the detection limit of dopamine. In virtue of various techniques, such as SEM and Raman spectroscopy, the morphological, structural and crystalline properties of composites were analyzed. Moreover, simultaneous determination of dopamine, ascorbic acid and uric acid was explored at the modified carbon fiber electrode. The presence of carbon nanotubes on the surface of carbon fiber can effectively increase the surface area and electron transfer velocity of the interaction between neurotransmitter and electrode. The good linear responses of ascorbic acid, dopamine and uric acid were obtained in the range of 25.6–2000.3 μM, 5.0–120.6 μM and 20.0–800.0 μM with detection limits (S/N = 3) of 10.0 μM, 0.03 μM and 0.6 μM, respectively. Finally, this sensor was applied to the determination of dopamine in some real sample. Keywords: Carbon fiber electrode, Carbon nanotube, Dopamine, Uric acid, Sensing

Nanoparticles have been developed for tumor treatment due to the enhanced permeability and retention effects. However, lack of specific cancer cells selectivity results in low delivery efficiency and undesired side effects. In that case, the stimuli-responsive nanoparticles system designed for the specific structure and physicochemical properties of tumors have attracted more and more attention of researchers. Esterase-responsive nanoparticle system is widely used due to the overexpressed esterase in tumor cells. For a rational designed esterase-responsive nanoparticle, ester bonds and nanoparticle structures are the key characters. In this review, we overviewed the design of esterase-responsive nanoparticles, including ester bonds design and nano-structure design, and analyzed the fitness of each design for different application. In the end, the outlook of esterase-responsive nanoparticle is looking forward.

Polymeric micelles (PMs) have been applied widely to transport hydrophobic drugs to tumor sites for cancer treatment. However, the low load efficiency of the drug in the PMs significantly reduces the therapeutic efficiency. We report here that disulfide-linked camptothecin (CPT) as a kind of dimeric drug can be effectively embedded in the core of poly(ε-caprolactone)–poly(ethylene glycol)–poly(ε-caprolactone) (PCL–PEG–PCL) PMs for improving drug-loading efficiency, and PEG can be used as a hydrophilic shell. Moreover, the dimeric CPT-loaded PCL–PEG–PCL PMs exhibited excellent solubility in phosphate-buffered saline (PBS) media and significant cytotoxicity to cancer cells.

In this paper, we reported a pH responsive nano drug delivery system (NDDS) based on ZnO quantum dots (QDs) for controlled release of drugs. Zwitterionic poly(carboxybetaine methacrylate) (PCBMA) and poly(2-(dimethylamino) ethyl methacrylate) (PDMAEMA) were introduced to modify ZnO QDs, which can help enhance water stability, increase blood circulation time, and promote endocytosis. After tuning of PCBMA/PDMAEMA ratios, the ZnO@P(CBMA-co-DMAEMA) nanoplatform shows a sensitive switch from strong protein adsorption resistance (with negatively charged surface) at physiological pH to strong adhesion to tumor cell membranes (with positively charged surface) at the slightly acidic extracellular pH of tumors. Anti-cancer drug, Doxorubicin (DOX), molecules were demonstrated to be successfully loaded to ZnO@P(CBMA-co-DMAEMA) with a relatively large drug loading content (24.6%). In addition, ZnO@P(CBMA-co-DMAEMA) loaded with DOX can achieve lysosomal acid degradation and release of DOX after endocytosis by tumor cells, resulting in synergistic treatment of cancer, which is attributed to a combination of the anticancer effect of Zn2+ and DOX.

Magnetic porous microspheres are widely used in modern wastewater treatment technology due to their simple and quick dye adsorption and separation functions. In this article, we prepared porous polymethylmethacrylate (PMMA) microspheres by the seed-swelling method, followed by in situ formation of iron oxide (Fe3O4) nanoparticles within the pore. Then, we used diazo-resin (DR) to encapsulate the porous magnetic microspheres and achieve PMMA@Fe3O4@DR magnetic material. We studied the different properties of magnetic microspheres by different dye adsorption experiments before and after the encapsulation and demonstrated that the PMMA@Fe3O4@DR microspheres can be successfully used as a reusable absorbent for fast and easy removal of anionic and aromatic dyes from wastewater and can maintain excellent magnetic and adsorption properties in harsh environments.

Humidity-sensitive poly(ethylene glycol) (PEG) inverse opals with micropatterns of 2 μm wide anti-swell-broken grooves were prepared using polystyrene (PS) colloidal crystals as templates and colloidal lithography. Monodisperse PS colloids were deposited in an ordered manner onto glass slides using a double-substrate vertical deposition method to form colloidal crystal templates. Poly(ethylene glycol) diacrylate (PEGDA) with photoinitiator was infiltrated into the interspaces of the colloidal crystals and photo-crosslinked by UV irradiation through a photomask. After removal the PS templates and unexposed PEGDA by tetrahydrofuran (THF), PEG hydrogel micropatterns with three-dimensional ordered porous structures were obtained. The band gaps of the PS colloidal crystals and corresponding PEG hydrogel inverse opals were measured by UV-VIS reflection spectrometer, calculated by Bragg law and simulated by Band SOLVE. The obtained PEG hydrogel inverse opal micropatterns can be used as sensors for humidity sensing due to absorption and desorption of moisture in the band gap structures. The sensor had a very reliable performance after repeated humidity sensing, and could be mass produced facilely with very low cost. The photopatterned anti-swell-broken grooves play an important role in the reliability of the sensors.

Indium tin oxide (ITO) is a transparent conductive material which is extensively used in organic solar cells (OSCs) as electrodes. In inverted OSCs, ITO is usually employed as a cathode, which should be modified by cathode buffer layers (CBLs) to achieve better contact with the active layers. In this paper, an amine group functionalized fullerene derivative (DMAPA-C60) is used as a CBL to modify the transparent cathode ITO in inverted OSCs based on PTB7 as a donor and PC71BM as an acceptor. Compared with traditional ZnO CBL, DMAPA-C60 exhibited comparable transmittance. OSCs based on DMAPA-C60 show much better device performance compared with their ZnO counterparts (power conversion efficiencies (PCEs) improved from 6.24 to 7.43%). This is mainly because a better contact between the DMAPA-C60 modified ITO and the active layer is formed, which leads to better electron transport and collection. Nanoscale morphologies also demonstrate that the surface of DMAPA-C60-modified ITO is plainer than the ZnO counterparts, which also leads to the better device performance.

Aminosilane- and dendrimer-modified silica nanoparticles were synthesized in the presence of (3-aminopropyl)trimethoxysilane and melamine-based dendrimer, respectively. The surface properties, morphology and carbon dioxide adsorption/desorption performances of the silica nanoparticles before and after surface modification were studied and compared. Severe aggregation of the silica nanoparticles was largely minimized after surface modification. The carbon dioxide adsorption capacity of the dendrimer-modified silica nanoparticles was significantly enhanced in comparison with the unmodified and aminosilane-modified silica nanoparticles because of the large surface area and presence of functional groups exhibiting CO 2 affinity in the former.

Convenient and low-cost dressings can reduce the difficulty of wound treatment. Alginate gel dressings have the advantages of low cost and safe usage, and they have obvious potential for development in biomedical materials. Alginate gel dressings are currently a research area of great interest owing to their versatility, intelligent, and their application attempts in treating complex wounds. We present a detailed summary of the preparation of alginate hydrogels and a study of their performance improvement. Herein, we summarize the various applications of alginate hydrogels. The research focuses in this area mainly include designing multifunctional dressings for the treatment of various wounds and fabricating specialized dressings to assist physicians in the treatment of complex wounds (TOC). This review gives an outlook for future directions in the field of alginate hydrogel dressings. We hope to attract more research interest and studies in alginate hydrogel dressings, thus contributing to the creation of low-cost and highly effective wound treatment materials. [ABSTRACT FROM AUTHOR]

This article presented a versatile and robust adsorbent with both magnetic property and high adsorption capacity on the basis of poly(glycidyl methacrylate)@ Fe3O4@diazoresin (PGMA@Fe3O4@DR) magnetic microspheres. The morphology, composition and magnetic properties of the magnetic microspheres were characterized by scanning electron microscope, Fourier transform infrared spectroscopy, thermogravimetric analysis and the hysteresis loop measurements, respectively. The obtained microspheres were applied in the adsorption of dye in the wastewater. The effects of adsorption time, initial dye concentration, pH value and other conditions were explored. Results show that the magnetic microspheres were able to remove more than 98.5% of dyes in water under optimized conditions. The use of diazoresin not only protects the Fe3O4 particles from being corroded at different pH values, but also greatly improves the adsorption capacity. [ABSTRACT FROM AUTHOR]

As a new minimally invasive technique, photothermal therapy has attracted worldwide attention in the treatment of cancer. Photothermal therapy kills cancer cells by converting photon energy into heat energy. At the time of selection, the photothermal agents will be required to be water solubility, cytotoxicity, high photothermal conversion efficiency, metabolic pathway and so on. This report introduces the current research status of various nanoparticles used in photothermal therapy, and looks forward to the future development of photothermal therapy. [ABSTRACT FROM AUTHOR]

Magnetic porous microspheres are widely used in modern wastewater treatment technology due to their simple and quick dye adsorption and separation functions. In this article, we prepared porous polymethylmethacrylate (PMMA) microspheres by the seed-swelling method, followed by in situ formation of iron oxide (Fe3O4) nanoparticles within the pore. Then, we used diazo-resin (DR) to encapsulate the porous magnetic microspheres and achieve PMMA@Fe3O4@DR magnetic material. We studied the different properties of magnetic microspheres by different dye adsorption experiments before and after the encapsulation and demonstrated that the PMMA@Fe3O4@DR microspheres can be successfully used as a reusable absorbent for fast and easy removal of anionic and aromatic dyes from wastewater and can maintain excellent magnetic and adsorption properties in harsh environments. [ABSTRACT FROM AUTHOR]

Recently, the solid phase extraction technology has received considerable attention considering serious environmental problems and much more contaminants present in the samples at trace level that is different to be analyzed. During the whole process of analyzing sample, the preconcentration of sample is the most complicated and significant step, which typically spend much time, affecting the analysis efficiency and accuracy of results to a large extent. Obviously, the sample pretreatment has become an obstacle that prevents us from improving analysis efficiency. If this problem cannot be resolved, the overall efficiency of analytical work will not be enhanced, even using the advanced analysis devices. As a result, increasing the success rate of sample pretreatment is especially necessary. Now, this review mainly represents the current development of solid phase extraction from the following aspects: (1) the type of adsorbent, including organic, polymer materials; (2) the different mode of separation, such as solid phase extraction, molecule imprinting solid phase extraction, solid phase microextraction, dispersive solid phase extraction, matrix solid phase dispersion, magnetic solid phase extraction, microchip solid phase extraction, stir bar sorptive extraction, immunoaffinity solid phase extraction, monolith solid phase extraction; (3) the practical applications of various solid phase extraction methods are also have been described in this article. [ABSTRACT FROM AUTHOR]

Column is the most critical part of the chromatographic separation. Monolithic column is a novel chromatographic column. The development of monolithic column significantly affects the development of chromatographic analysis. Monolithic column possesses high column efficiency and can reduce the analysis time as the permeability efficiency improves. Especially in protein separation, the superior and unique porous structure of monolithic column could enhance the permeability of proteins separation and improve separation efficiency. Recently, monolithic columns are developing rapidly due to their fascinating properties and enormous application. In this paper, recent development and application of monolithic columns are reviewed, which will deepen people's understanding of this field and have profound implications for future design of high-efficiency monolithic column. [ABSTRACT FROM AUTHOR]

Microfluidic chip electrophoresis (MCE) is a powerful separation tool for biomacromolecule analysis. However, adsorption of biomacromolecules, particularly proteins onto microfluidic channels severely degrades the separation performance of MCE. In this paper, an anti-protein-fouling MCE was fabricated using a novel sandwich photolithography of poly(ethylene glycol) (PEG) prepolymers. Photopatterned microchannel with a minimum resolution of 10 μm was achieved. After equipped with a conventional online electrochemical detector, the device enabled baseline separation of bovine serum albumin, lysozyme (Lys), and cytochrome c (Cyt-c) in 53 s under a voltage of 200 V. Compared with a traditional polydimethylsiloxane MCE made by soft lithography, the PEG MCE made by the sandwich photolithography not only eliminated the need of a master mold and the additional modification process of the microchannel but also showed excellent anti-protein-fouling properties for protein separation. [ABSTRACT FROM AUTHOR]

The research on polymer membranes for gas separation has surprisingly blossomed during recent decades. Many modification techniques have been developed to improve the separation properties of polymermembranes. In this review, we give a systematic summary of the main aspect of polymeric gas separation membranes related to their physical and chemical modification, and propose perspectives for the future developments. [ABSTRACT FROM AUTHOR]

A simple and effective universal serial bus (USB) flash disk type microfluidic chip electrophoresis (MCE) was developed by using poly(dimethylsiloxane) based soft lithography and dry film based printed circuit board etching techniques in this paper. The MCE had a microchannel diameter of 375 μm and an effective length of 25 mm. Equipped with a conventional online electrochemical detector, the device enabled effectively separation of bovine serum albumin, lysozyme, and cytochrome c in 80 s under the ultra low voltage from a computer USB interface. Compared with traditional capillary electrophoresis, the USB flash disk type MCE is not only portable and inexpensive but also fast with high separation efficiency. [ABSTRACT FROM AUTHOR]

Formation of a very stable, unprecedented pyrazole-ring fused derivative of endohedral metallofullerenes was achieved by the first 1,3-dipolar cycloaddition reaction of Sc3N@C80 with diphenylnitrilimine in a highly regioselective manner. [ABSTRACT FROM AUTHOR]

An effective microfluidic method to fabricate monodisperse polyethylene glycol (PEG) hydrogel composite microspheres with tunable dimensions and properties is reported in this paper. A T-junction microfluidic chip equipped with rounded channels and online photopolymerization system is applied for the microsphere microfabrication. The shape and size of the microspheres are well controlled by the rounded channels and PEG prepolymer/silicon oil flow rate ratios. The obtained PEG/aspirin composite microspheres exhibit a sustained release of aspirin for a wide time range; the obtained PEG/Fe3O4 nanocomposite microspheres exhibit excellent magnetic properties; and the obtained binary PEG/dye composite microspheres show the ability to synchronously load two functional components in the same peanut-shaped or Janus hydrogel particles. [ABSTRACT FROM AUTHOR]

Aminosilane-modified poly(ethylene glycol) (PEG), PEG-block-poly(propylene glycol) (PPG)-block-PEG (PEPEG), and PPG-block-PEG-block-PPG (PPEPG) diacrylate prepolymers are synthesized as new membrane materials for gas separation. By combining the in situ sol−gel process and cross-linking process together, the silane-modified prepolymers form flexible nanocomposite membranes with a maximum CO2permeability of 274 barrer and CO2/N2selectivity of about 30. The CO2permeabilities of silane cross-linked PEPEG and PPEPG membranes are higher than those of silane cross-linked PEG membranes, whereas the CO2/N2and CO2/H2selectivities increase as the PEG content increases in the membrane. A proper aminosilane/prepolymer reaction ratio benefits the gas separation performance of the membrane due to the formation of different cross-linking structures and composites. [ABSTRACT FROM AUTHOR]

In this paper, we present a novel rapid-prototyping process for out-of-cleanroom microfabrication of three-dimensional multilayer microfluidic structures with a 10 µm resolution, referred to as the Direct Projection on Dry-film Photoresist (DP2). A commercially available digital projector is customized to function as a direct mask generation and photo exposure system, while easy-processing photosensitive dry films are used as the microfluidic constructs. Multilayer alignments among maskless-patterned layers are reliably achieved by using a Software Alignment technique with less than 10 µm precision, which eliminates the use of mechanical travelling stage. The bonding between different layers of dry film, simply enabled by a plasma-assisted thermal lamination, offers an easy implementation for suspended multilayer microstructures. Development of a complex microfluidic chip from computer layout can thus be accomplished within an hour in a regular chemical or biological lab environment using this approach. [ABSTRACT FROM AUTHOR]

Brominated poly(2,6-diphenyl-1,4-phenylene oxide) (BPPOdp) is synthesized as a new membrane material for gas separation. BPPOdpforms flexible membranes with higher CO2permeability (PCO278 Barrer) and selectivity (CO2/N230) than poly(2,6-dimethyl-1,4-phenylene oxide) (PPOdm) membranes. BPPOdpalso forms nanocomposite membranes with silica nanoparticles. The nanocomposite membranes have a greatly enhanced CO2permeability while maintaining the CO2/N2and CO2/CH4selectivities of the pure BPPOdpmembranes. The CO2permeability increases as the silica content increases in the membrane. The 10-nm silica nanoparticles are more effective at increasing the CO2permeability than the 30-nm silica nanoparticles. Mechanism studies show that the enhanced permeability results from the nanogaps between the silica nanoparticles and the polymer chains due to their incompatibility. [ABSTRACT FROM AUTHOR]

Silica-impregnated, brominated PPO poly(phenylene oxide) (BPPO) membranes exhibit enhanced CO2permeability relative to pure BPPO membranes due to higher gas solubility and especially higher gas diffusivity. Among the three silica sizes (2, 10, and 30 nm) characterized in this work, the 10 nm silica is found to result in the highest gas permeability, about 5 times higher than that of the pure BPPO membranes. These permeability enhancements do not cause an appreciable loss of selectivity, which remains essentially unchanged, for example, about 21 for the CO2/N2separation and about 15 for the CO2/CH4separation. The permeability increases with increasing silica content, which, however, cannot exceed about 0.35 silica/BPPO weight ratio due to a substantial increase in brittleness. [ABSTRACT FROM AUTHOR]

Multifunctional nanomedicines featuring high drug loading capacity, controllable drug release and real-time self-monitoring are attracting increasing attention due to their potential to improve cancer therapeutic efficacy. Herein, a new kind of Fe3O4@C-based nanoparticles modified with isoreticular metal organic frameworks (IRMOF-3), folic acid (FA) and detachable polyethylene glycol (PEG) under tumor microenvironment was developed. The core-shell structured Fe3O4@C was synthesized via the one-pot solvothermal reaction and the IRMOF-3 layers were coated on the outer shell of Fe3O4@C through layer-by-layer coating method. The FA and PEG were conjugated on the surface of nanoparticles by reacting with the amine groups provided by IRMOF-3. The as-synthesized nanoparticles showed stable photothermal effect, superparamagnetic properties and blue fluorescence characteristic under 360 nm irradiation. The in vitro experiments showed that the drug loaded nanoparticles exhibit pH-dependent drug release property, and PEGylation was proved effective in suppressing burst drug release (only 8.0% of drugs were released within 95 h). The confocal laser scanning microscopy study revealed that the as-synthesized nanoparticles could serve as a cell imaging agent and the cell internalization can be significantly enhanced after FA modified. The IRMOF-3 modified nanoparticles showed negligible cytotoxicity and the drug loaded nanoparticles showed pH/photothermal-stimuli enhanced cytotoxicity in vitro. It is believed that the present smart drug delivery platforms will hold great potential in imaging guided drug delivery and cancer therapy. [ABSTRACT FROM AUTHOR]

A preface to the journal "The 14th China International Nanoscience and Technology Symposium" is presented.

Since its discovery in 1990, microfluidic chip electrophoresis (MCE) has allowed the development of applications with small size, fast analysis, low cost, high integration density and automatic level, which are easy to carry and have made commercialization efficient. MCE has been widely used in the areas of environmental protection, biochemistry, medicine and health, clinical testing, judicial expertise, food sanitation, pharmaceutical checking, drug testing, agrochemistry, biomedical engineering and life science. As one of the foremost fields in the research of capillary electrophoresis, MCE is the ultimate frontier to develop the miniaturized, integrated, automated all-in-one instruments needed in modern analytical chemistry. By adopting the advanced technologies of micro-machining, lasers and microelectronics, and the latest research achievements in analytical chemistry and biochemistry, the sampling, separation and detection systems of commonly used capillary electrophoresis are integrated with high densities onto glass, quartz, silicon or polymer wafers to form the MCE, which can finish the analysis of multi-step operations such as injection, enrichment, reaction, derivatization, separation, and collection of samples in a portable, efficient and super high speed manner. With reference to the different technological achievements in this area, the latest developments in MCE are reviewed in this article. The preparation mechanisms, surface modifications, and properties of different materials in MCE are compared, and the different sampling, separation and detection systems in MCE are summarized. The performance of MCE in analysis of fluorescent substance, metallic ion, sugar, medicine, nucleic acid, DNA, amino acid, polypeptide and protein is discussed, and the future direction of development is forecast. [ABSTRACT FROM AUTHOR]

In this paper, a nanocomposite approach is introduced to provide both electrically conductive and optically transparent micropatterns on any flexible substrate employing photolithography-based microfabrication. The nanocomposite materials combine the highly directional nanoscopic networks and electrical conductivity of single-wall carbon nanotubes (SWNTs) with the photopatternability and optical transparency of SU-8 photoresist. The photopatternable nanocomposites have yielded high optical transparency of 90% and high electrical conductivity of 27.5 S m[?]1 with the minimal feature resolution of 10 um. Additionally, an interesting nano-bridge phenomenon has been discovered during fabrication of the microscale features. Moreover, the photopatternable transparent conductive nanocomposite has demonstrated its application to biomedical sensing for exceptional adaptability and flexibility. [ABSTRACT FROM AUTHOR]

In this paper, we report on the effect of patterned non-adhesive hydrogel nanosurfaces on the self-assembly of highly ordered colloids. Polyethylene glycol (PEG) hydrogel is employed as the substrate material in the study, for its desired non-adhesive property, and biocompatibility as well as photopatternability. Ultrafine PEG features are photopatterned onto glass substrates with minimal feature resolution of 500 nm using ultraviolet or deep ultraviolet exposure. By simply controlling the colloidal concentration of the nanoassembly solutions and the dimensions of the wells, a range of highly organized nanocolloidal patterns are formed inside the PEG wells. Unlike the traditional surface modification techniques, ours takes advantage of the unique non-adhesive property of PEG hydrogels to achieve extremely high selectivity in the pattern-assisted nanoassembly. Our experiments show that with oxygen plasma treatment, the non-adhesive property of the PEG surface deteriorates significantly, leading to non-selective assembly with complete surface coverage of nanocolloidal beads under the same processing condition. Therefore, benefiting from the unique non-adhesive surface property, the pattern-assisted nanoassembly method enables a highly predictable and robust process for colloidal nanofabrication, and the obtained nanocolloidal arrays with well organized patterns could potentially find applications in photonic crystal fabrication, biological sensing and analytical detection. [ABSTRACT FROM AUTHOR]