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In this work, a pH-tunable multicolor luminescent lanthanide-based hydrogel (CS/DEX/CP) was prepared based on lanthanide coordination polymer (CP), dextran aldehyde (DEX) and chitosan (CS). The CP was obtained by the self-assembly of guanosine acid (GMP), ciprofloxacin (CIP), Eu3+, and Tb3+. As-prepared CS/DEX/CP hydrogel could emit blue, green, and red luminescence of CIP, Tb3+, and Eu3+, respectively. It was also found that the luminescence of CS/DEX/CP hydrogel exhibited visual color change in the pH range of 5.5 to 8. Such pH-sensitive hydrogel was multicolor-responsive to protons produced by bacterial growth, therefore, it could provide early warning of bacterial infection by Naked-eye. In addition, the increased acidity resulted in not only the degradation of acid-labile Schiff base linkages between DEX and CS, but also the fracture of coordination between CIP and lanthanide ions. As a result, the released CIP and CS showed significantly antibacterial activity against both S.aureus and E. coli.

Full visible spectrum photonic droplets and consequent microcapsules with nano-in-micro structure were prepared through microfluidic technique. Photo-curable resin and suspension of monodispersed soft nanogels were used as shell and core of the microcapsules, respectively. Upon UV irradiation, the droplets can be subsequently transformed into photonic microcapsules with an ultrathin polymeric shell. The shell thickness of the photonic microcapsules was found to be approximately 700 nm. Due to the ultrathin shell and soft core, the photonic microcapsules with nano-in-micro structure display dramatic changes both in shapes and photonic property under the impact of osmosis effect or temperature stimulus. Typically, the shell and core parts of nano-in-micro structure could respectively undergo a size expansion/even rupture and a size decrease/buckling under hypotonic and hypertonic condition. Correspondingly, the peak value of the reflection spectra of the microcapsules showed a redshift and blue shift, respectively. The mechanism to the structure and optical properties variation involves the osmotic pressure induced the volume-fraction change of the nanogel-based photonic dispersion and the shell buckling of the core/shell microcapsules.

In this work, we reported a multi-responsive luminescent hydrogel with properties of encryption, naked eye sensing of glucose, shape memory, self-healing, and antibacterial activity. The hydrogel (GA/CCS/DNSA/Eu3+) was obtained by mixing phenylboronic acid-modified gelatin (GA-DBA), catechol-modified carboxymethyl chitosan (CCS-PCA), 3,5-dinitrosalicylic acid (DNSA), and Eu3+ ions through a facile heating-cooling process. The resultant hydrogel exhibits reversible luminescence and color and phase changes in response to temperature, acid/base, salt, and redox stimuli. Based on the multiple responsiveness, information encryption and decryption, naked eye sensing of glucose, remarkable shape memory, and enhanced mechanical properties of the as-prepared hydrogel were realized. In addition, the self-healing capacity was also achieved due to the dynamic bonds in GA/CCS/DNSA/Eu3+ hydrogels. Specifically, the GA/CCS/DNSA/Eu3+ hydrogels possess antibacterial activity owing to the bacteriostasis of the CCS-PCA and DNSA/Eu3+ complex. Thus, GA/CCS/DNSA/Eu3+ hydrogels have potential applications in the fields of anticounterfeiting, wearable devices, biomedicine, sensing, etc.

Injectable hydrogels have been developed as biomedical materials in various fields but the biofouling on their surface limits applications in vivo. In this work, a zwitterionic structure was introduced into an injectable hydrogel based on thermosensitive nanogels to overcome the foreign body reaction. The hydrodynamic diameter of the resultant poly(N-isopropylacrylamide-co-sulfobetaine methacrylate) (PNS) nanogels was ca. 105 nm. The aqueous dispersion with a high content of PNS nanogels showed a flowable sol state at room temperature, and turned into a hydrogel in situ at ∼36 °C due to the thermosensitivity of the PNS nanogels. In particular, the resulting hydrogel exhibited lower biofouling both in vitro and in vivo in comparison with similar hydrogels without a zwitterionic structure. Polydopamine nanoparticles (PDA NPs) as a photothermal agent and an anti-tumour drug could be easily co-loaded in the injectable hydrogel. Under near-infrared (NIR) irradiation for 10 min, the temperature of the PNS system containing PDA NPs could reach ca. 38 °C. The drug release from the in situ-forming hydrogel could be accelerated by NIR laser irradiation, and showed a sustainable release behavior and adjustability. The results of intratumoral injection of the as-prepared injectable hydrogel containing PDA NPs and an anti-tumour drug showed significant anticancer effects combining photothermal therapy and local chemotherapy. This constructed injectable zwitterionic thermosensitive hydrogel is easy to use with the advantage of low-fouling and may become a promising platform for various biomedical applications.

Multifunctional alginate microspheres encapsulated with in situ-formed bismuth sulfide nanoparticles (denoted as Bi2S3@BCA) were developed in this work. In comparison with conventional hybrid polymer microspheres usually involved in complicate preparation process, Bi2S3@BCA microspheres can be easily one-step prepared using a droplet-based microfluidic technique with alginate as a soft template and microspheric matrix. As-prepared Bi2S3@BCA microspheres has unique nano-in-micro structure. The obtained wet microspheres show good uniform size with approximately 170 μm in diameter. Scanning electron microscopy images show that Bi2S3 nanoparticles with a size of 300 nm were homogeneously distributed in the microspheres. In addition, Bi2S3@BCA microspheres exhibit strong absorption of near-infrared (NIR) light and excellent photothermal effect in vitro. Furthermore, anti-cancer drug (doxorubicin)-loaded Bi2S3@BCA microspheres show sustained drug release behavior and enhanced release rate under NIR laser irradiation. The in vitro cytotoxicity experiments confirm that chemotherapy combined with NIR-induced hyperthermia can act synergistic effect to kill more tumor cells. Therefore, the as-prepared drug-loaded Bi2S3@BCA microspheres may potentially be used as a novel embolic material for tumor therapy due to their multifunction including embolization, hyperthermia and controlled local chemotherapy.

Micelle-hybridized supramolecular hydrogels were constructed through the self-assembly of gelator N,N-dibenzoyl-L-cystine (DBC) and micelles formed from a Gemini surfactant (G12-8-12). A phosphor, palladium meso-tetra (4-carboxyphenyl) porphyrin (Pd-TCPP) and Al3+ ions were loaded within the hybrid system. Interestingly, the room temperature phosphorescence (RTP) of Pd-TCPP can be efficiently enhanced and modulated by the concentration of Al3+ ions. The enhancement effect could be attributed to the interactions between Al3+ and DBC as well as porphyrin, which verified by 1H NMR analysis. The study of transmission electron microscopy and scanning electron microscopy indicated that a more compact 3D network structure of the gel system was formed upon the addition of Al3+. In addition, measurement of critical micelle concentration indicated that Al3+ ions increase the surface activity of G12-8-12 to promote micelle formation, thereby increasing the dispersion of Pd-TCPP in the hybrid gels. Based on the synergistic effect of these results, the non-radiative transition of Pd-TCPP was efficiently inhibited, resulting in highly efficient RTP. Furthermore, the enhanced RTP of as-prepared gel system shows potential application to detect trace Hg2+ ions because the RTP can be quenched by Hg2+. A linear relationship between RTP against the logarithmic concentration of Hg2+ was found over the range of 6 × 10−8 and 1 × 10−6 mol/L. The detection limit was found to be 0.017 nmol/L.

In this work, the luminescence of lanthanide supramolecular metallogel formed by the self-assembly of 5,5′,5″-(1,3,5-triazine-2,4,6-triyl)tris(azanediyl)triisophthalate (H6L) and Tb3+ was efficiently promoted by carboxymethyl chitosan (CMCS). The total quantum yield of the resultant metallogel (denoted as H6L/Tb3+/CMCS gel) was 9 times higher than the gel without CMCS. The average lifetime of H6L/Tb3+/CMCS gel increased from 0.51 ms to 1.20 ms. More importantly, the aqueous dispersion of H6L/Tb3+/CMCS xerogels showed a stable and pH-dependent luminescence. Based on the selective affinity of CMCS to different metal ions as well as with the aid of principal component analysis, H6L/Tb3+ /CMCS can be used as a sensor array to distinguish 11 metal ions (P

This work is to develop a kind of multifunctional embolic material, which will possess a synergized tumor ablation effect combining transcatheter arterial chemoembolization and hyperthermia therapy. Herein, monodispersed calcium alginate (CA) microspheres containing gold nanostars (Au NSs) have been prepared in one step by using a droplet-based microfluidic technique. The droplets containing sodium alginate (SA) and HAuCl4 formed in the microfluidic device are solidified by Ca2+ to obtain CA microspheres while HAuCl4 is successively reduced to Au(0) by SA and vitamin C in the collecting solution to produce Au NSs in situ-encapsulated in CA microspheres. Herein, alginate acts as a co-reducing agent and stabilizer for in situ-formed Au NSs, and also as a drug carrier and embolic agent. Studies of scanning electronic microscopy combined with energy-dispersive X-ray spectroscopy, transmission electronic microscopy and X-ray diffraction verified the existence and morphology of the in situ-formed Au NSs. The as-prepared microspheres can absorb near-infrared (NIR) light and the temperature increment of the microsphere suspension can be more than 60 °C under NIR irradiation due to the presence of Au NSs. The drug release rate can be accelerated by NIR irradiation. The study of in vitro cytotoxicity indicates that tumor cells can be efficiently killed by the combination of chemotherapy and NIR-induced hyperthermia. As potential embolic materials, the hybrid microspheres provide new insights into synergistic therapy of cancer.

Although photothermal therapy (PTT) can effectively eliminate tumors, the normal tissues near tumors are inevitably damaged by heat and infected by bacteria, which greatly limits the therapeutic effect. In this work, an injectable thermosensitive hydrogel based on iodine-loaded starch-g-poly(N-isopropylacrylamide) (PNSI) is developed to overcome this problem. FTIR

It is crucial to develop dual or multi-modal self-imaging embolic microspheres to evaluate the effects of transcatheter arterial embolization therapy of tumor. However, the preparation of such hybrid microspheres always involved in multiple steps or complicated conditions. Here, poly(vinyl alcohol) (PVA) hybrid microspheres with dual-modal T1/T2-weighted magnetic resonance imaging (MRI) have been prepared based on microfluidic technique in one step. Gd2O3 and Fe3O4 nanoparticles with a size of ~5 nm act as T1- and T2-weighted MRI contrast agents, respectively, which are simultaneously in-situ synthesized in the PVA matrix via the reaction of metal ions and alkali with PVA chains as a soft template. Meanwhile, these metallic-oxide nanoparticles act as cross-linker to gelatinize the PVA droplets to obtain nano-in-micro PVA microspheres in one step. This procedure is simple, economic and feasible. The obtained nano-in-micro PVA microspheres show good magnetothermal effect, enhanced T1- and T2-weighted MRI and embolization effect.

In this work, 5,5′,5′′-(1,3,5-triazine-2,4,6-triyl)tris(azanediyl)triisophthalate (H6L) was used as a gelator to prepare thermostable supramolecular gels (H6L gels). The lowest critical gelation concentration of H6L was found to be only 0.14 wt%. H6L gels remained stable after being placed at 85 °C for 1 h, indicating that its gel-sol phase transition temperature (Tgel) was not

Halloysites are a kind of aluminosilicate clay with a morphology of a nanotube. The inner wall of halloysite is positively charged, and the external surface is negatively charged. In this work, we propose a simple and facile method to prepare Ag NPs loaded in the lumen of halloysite nanotubes (HNTs). Herein, N-acetyl-l-cysteine modified silver nanoparticles (Ag NPs) with negative charges spontaneously and stably resided in the lumen of HNTs via electrostatic interactions. The images of transmission electron microscopy and scanning transmission electron microscopy showed that Ag NPs with a size of ~2.6 nm were uniformly distributed in the lumen of HNTs. The catalytic activity of the obtained Ag NPs/HNTs composites was evaluated by the reduction reaction of 4-nitrophenol (4-NP) as a model reaction. When the molar ratio of Ag and 4-NP was set at 0.008, the rate constant of the reaction was found to be 0.91 min−1, two times higher than that of Ag NPs adsorbed on the external surface of HNTs. Additionally, no Ag NPs were found in the supernatant after the Ag NPs/HNTs suspension was stirred for 30 min. Such structural stability implies good reusability as a catalyst.

Preparing luminescence-stable lanthanide materials in a facile manner has always been an intriguing challenge. Herein we report an easy approach to the preparation of a heat-set lanthanide-based metallogel (H6L/Tb gel) with stable luminescence from 5,5',5''-(1,3,5-triazine-2,4,6-triyl)tris(azanediyl) triisophthalate (H6L) as a Tb3+ coordinating ligand. The heat-set H6L/Tb gel exhibits luminescence that mostly retains its intensity in the 0-90 °C temperature range and under mechanical stimulus. In addition, the H6L/Tb xerogel is also luminescent in aqueous solution. UV-vis and FT-IR spectroscopy and XRD studies reveal that the stable luminescence of the H6L/Tb gel depends on heat-set-induced strong hydrogen bonding, π-π stacking, and metal-ligand interactions. This study provides a heat-set approach to the preparation of luminescence-stable metallogel materials, such metallogels are potentially useful in anti-counterfeiting and sensing fields, among others.

The development of reversible redox supramolecular gels capable of concurrent luminescence switch and visible color change with the facile redox process has always been an intriguing challenge. A redox-responsive supramolecular lanthanide metallogel with strong luminescence and yellow color is obtained via coordination interaction between 3,5-dinitrosalicylic acid (DNSA) and europium (Eu

Conducting hydrogels were obtained through high-pressure induced gelation of poly(vinyl alcohol) aqueous solutions and subsequent in-situ polymerization of aniline (polyaniline). A study of scanning electron microscopy showed that polyaniline was homogeneously dispersed within the 3D nano-network matrix of the poly(vinyl alcohol) hydrogels. The UV–vis spectra and cyclic voltammetry of the hydrogels demonstrated that the high-pressure treatment had no influence on the in-situ polymerization and electrochemical feature of polyaniline. A study of electrochemical impedance indicated that the conducting hydrogels possessed electrical conductivity and potential application in the field of biomaterials and electrode materials of supercapacitors.

A facile fabrication strategy of fluorescence-phosphorescence dual emissive materials based on the supramolecular gels was proposed in this work. In comparison with complicated fabrication of conversional dual emissive materials, supramolecular gels are formed just through a simple heating and cooling of solution containing a gelator and phosphor. The gel system is pure organic without any metal ions. Herein, the self-assembly of gelator N, N-dibenzoyl- l -cystine (DBC) resulted in the formation of gel system. The phosphor 3,5-Dibromoquinoline (BrQ) entrapped in the gels endowed gels with fluorescence-phosphorescence dual emission. Upon 315 nm UV irradiation, strong room temperature fluorescence and phosphorescence emission were observed at 367 and 550 nm, respectively. The ability of dual emission at room temperature could be attributed to the ordered microstructure of the supramolecular gels, effectively avoiding the non-radiative transition of BrQ. In addition, the gel system exhibited environmental responsiveness including thermal, pH and redox response due to the structural feature of DBC gels. The dual emission can be tuned by this responsiveness. Particularly, the deoxygenation of gel system is not required. Conversely, the dissolved oxygen in the system can be employed for redox reaction without the addition of any other oxidant.

An inherent disadvantage of supramolecular gels is the lack of mechanical strength. In this work, we made an attempt to improve their mechanical strength through the adding hydrophobically modified halloysite nanotubes (HNTs) with in-situ formed Fe3O4 nanoparticles. Briefly, the magnetic supramolecular gel composites were prepared through adding 2 wt% benzyl sorbitol derivatives as the gelators into the solvents containing magnetic HNTs. It was found that the compressive strength of the reinforced supramolecular gel composites was remarkably increased from 19 kPa to 28 kPa by adding only 4 wt% of magnetic HNTs. The resultant magnetic supramolecular gel composites possess formability due to their sufficient mechanical strength and exhibit excellent properties for dye adsorption. Significantly, such magnetic supramolecular gel composites can be easily separated from the dye solutions by using an external magnet.

Glutathione–Ag (GSH–Ag) supramolecular hydrogels have almost no mechanical strength, and the disassembly of GSH–Ag complexes occurs very easily under UV irradiation. In this work, low molecular weight polyvinyl alcohol (PVA) was used to reinforce GSH–Ag gels. The phase transition temperature of GSH–Ag gels can be increased from 45 to 60 °C in the presence of only 0.8 wt% of PVA. Rheological studies indicated that the storage modulus of reinforced GSH–Ag gels was 6 times higher than that of unreinforced gels. SEM studies revealed that the macromolecular chains of PVA are intertwined with the GSH–Ag aggregates, leading to an increase of mechanical strength. The TEM studies and UV-vis spectra indicated that Ag+ within the GSH–Ag gels was in situ reduced to form Ag nanoparticles under UV irradiation. Meanwhile, gradual disassembly of GSH–Ag hydrogels can be induced through controlling the time of UV irradiation. Based on this feature, the controllable release of a loaded model drug (crystal violet) and Ag species can be realized from the reinforced GSH–Ag gels. The release media show a good inhibition effect on E. coli.

Monodispersed spherical calcium alginate microgels (denoted as Ca-ALG) with uniform and controllable size were prepared by using a microfluidics technique. Herein, an aqueous solution of sodium alginate (denoted as Na-ALG) was used as a dispersed phase, and the liquid paraffin containing CaCl 2 nanoparticles formed in situ was used as a continuous phase. Na-ALG droplets were first pre-crosslinked by CaCl 2 diffused from the oil phase in the microchannel, and then crosslinked completely in the collection bath containing an aqueous solution of CaCl 2 . In comparison with conventional external crosslinking, this method can avoid deformation of microgels which usually occurs in the process of external crosslinking. Due to the pre-crosslinking of Na-ALG droplets in the microchannel, the spherical morphology of the microgels could not be affected by the preparation conditions, such as types of microfluidic devices, flow rate ratios of the continuous phase and dispersed phase, size of the droplets, collection height and so on. In addition, the size of the spherical Ca-ALG microgels can be well controlled from 40 to 700 μm in diameter by changing the dimension of the microchannels and the flow rate ratios of the dispersed phase and continuous phase. Furthermore, such spherical Ca-ALG microgels can improve their movement and packing state in a microchannel, which is beneficial for their use as embolic materials for interventional therapy.

Due to the very poor mechanical strength of polyaniline-poly(styrene sulfonate) (PANI-PSS) conducting hydrogels, we explored the possibility to improve the strength of PANI-PSS hydrogels using supramolecular nanofibers formed by self-assembly of sorbitol derivatives (DBS). The compressive strength of these reinforced hydrogels was found to be 11 times higher than that of the unreinforced one. SEM studies indicated that the in-situ formed DBS nanofibers and PANI-PSS chains are entangled, leading to improvement of the hydrogel strength. The conductivity of reinforced hydrogels measured by impedance was found to be 10−4 S/cm, rather similar to that of the unreinforced hydrogels. In addition, the spectra of cyclic voltammetry for the reinforced and unreinforced hydrogels were almost the same. These results reveal that the presence of DBS nanofibers does not affect the electric properties of PANI-PSS hydrogels. As drug carriers with electric-driven release, the release rate of model drug Rhodamine B loaded within reinforced PANI-PSS hydrogels distinctly increased when an increase of voltage was applied. Furthermore, a pulse release could be realized when the voltage was alternatively applied.

It is crucial to develop dual or multi-modal self-imaging embolic microspheres to evaluate the effects of transcatheter arterial embolization therapy of tumor. However, the preparation of such hybrid microspheres always involved in multiple steps or complicated conditions. Here, poly(vinyl alcohol) (PVA) hybrid microspheres with dual-modal T

Qin Wang,1 Shanshan Liu,1 Fan Yang,2 Lu Gan,3 Xiangliang Yang,3 Yajiang Yang1 1National Engineering Research Center for Nanomedicine, School of Chemistry and Chemical Engineering, 2Department of Radiology, Union Hospital, Tongji Medical College, 3National Engineering Research Center for Nanomedicine, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, China Abstract: Alginate microspheres loaded with superparamagnetic iron oxide nanoparticles (SPIO NPs) have been fabricated by a T-junction microfluidic device combined with an external ionic crosslinking. The obtained microspheres possess excellent visuality under magnetic resonance due to the presence of only 0.6 mg/mL SPIO NPs. The microspheres also show uniform size with narrow distribution and regular spherical shape characterized by optic microscope and environmental scanning electron microscope. Furthermore, dual drugs (5-fluorouracil and doxorubicin hydrochloride) have been loaded within the microspheres. The release behavior of dual drugs from the microspheres show typical sustained release profiles. As a novel embolic agent, such microspheres in blood vessels can be tracked by magnetic resonance scanner. Thus, the integration of embolotherapy, chemotherapy, and postoperative diagnosis can be realized. Keywords: MRI visuality, chemoembolization, microfluidics, dual drugs, alginate micro­spheres&nbsp

In general, dissolved oxygen in luminescent systems is a typical quencher for phosphors and usually needs to be removed from the system. In this work, we reported enhancing room temperature phosphorescence (RTP) assisted by dissolved oxygen. Herein, meso-tetra (carbonyl phenyl) palladium-porphyrin (Pd-TCPP) was used as phosphor and encapsulated within micelle-hybridized supramolecular gels formed by gelator N, N′-dibenzoyl- l -cysteine (DBC) and Gemini surfactant dodecyl-α, ω-bis (N, N-dimethyl-N-dodecylammonium bromides, G12-12-12). After UV irradiation for 10 min, RTP intensity of the gel system was found to be ∼100 times higher than that of the gel without UV irradiation. RTP enhancing mechanism involved the role of singlet oxygen generated from the dissolved oxygen under UV irradiation. Due to the disulfide group of DBC was oxidized by the singlet oxygen to sulfonic acid group, two types of interaction were caused. One of them was electrostatic interactions between the negatively charged moiety of sulfonic group and positively charged moiety of G12-12-12. Another was stronger hydrogen bonding between sulfonic groups of DBC aggregates. Under these two interactions, the supramolecular 3D network structure of the gel system became denser. The freedom and the probability of non-radiation transition of Pd-TCPP was more restricted, leading to RTP enhanced. Moreover, the RTP can be readily regulated by varying the time and power of UV irradiation.

Luminescent supramolecular metallogels based on the coordinating interaction of lanthanide ions and Fmoc-L-phenylalanine were prepared at room temperature within several seconds. The prepared metallogels exhibited strong characteristic luminescent behavior of lanthanide ions. The formation mechanism of metallogels was investigated by scanning electron microscopy, 1H NMR, FT-IR as well as UV–Vis spectroscopy. The results indicated that the formation mechanism involved the synergistic effect between lanthanide metal-ligand coordination, π-π stacking and hydrogen bonding. The prepared metallogels showed excellent thermally stable luminescence, which may be attributed to their thermally stable structure. Additionally, the reversible “on-off” luminescence effect could be achieved by alternately titrating NaOH and HCl into the metallogels. Therefore, the metallogels could be potentially used as sensors and luminescent materials.

Novel conducting hydrogels (PVA-TA) with dual network structures were synthesized by the grafting reaction of tetraaniline (TA) into the main chains of poly(vinyl alcohol) and in situ reinforced by self-assembly of a sorbitol derivative as the gelator. The chemical structure of the PVA-TA hydrogels was characterized by using FT-IR and NMR. The mechanical strength of the PVA-TA hydrogels was strongly improved due to the presence of supramolecular nanofibers. For instance, the compressive and tensile strengths of supramolecular nanofiber-reinforced hydrogels were, respectively, 10 times and 5 times higher than those of PVA-TA hydrogels. Their storage modulus (G') and loss modulus (G″) were 5 times and 21 times higher than those of PVA-TA hydrogels, respectively. Cyclic voltammetry and conductivity measurements indicated that the electroactivity of reinforced hydrogels is not influenced by the presence of supramolecular nanofibers.

By using the in situ polymerization of aniline in an aqueous solution of sodium alginate, we prepared reinforced conducting hydrogels (PANI–SA) with good conductivity (∼10−3 S cm−1). SEM images indicated that the microstructure of PANI–SA hydrogels was a typical 3D nano-fiber network formed by the entanglement of the PANI and SA molecular chains, leading to a good compressive strength (∼41 kPa). Because the system does not contain any adhesives and conducting fillers, the PANI–SA conducting hydrogels with self-supported structures can be directly employed as electrode materials for supercapacitors. A study of cyclic voltammograms indicated that the currents of the cathodic peak significantly increased with an increase in the scan rate, indicating that the electrode materials possess good responsiveness. As a reference, traditional compressive tablet electrodes were also prepared by mixing the powder of PANI–SA xerogels, adhesive and conducting filler. The results of galvanostatic charge/discharge and impedance show that PANI–SA hydrogels possess longer discharge times, higher specific capacitance and lower electronic resistance in comparison with compressive tablet electrodes. After 1000 cycles of charge/discharge, there is almost no difference in the retained specific capacitance between PANI–SA hydrogels electrodes and compressive tablet electrodes. The easily fabricated PANI–SA conducting hydrogels show great potential as electrode materials for supercapacitors.

Microemulsions were prepared by using Tween 80 as a surfactant, 1,2-propylene glycol as a co-surfactant, isopropyl myristate as an oil phase and phosphate-buffered saline as an aqueous phase. The resultant microemulsions possess a bicontinuous-phase structure which was characterized by pseudo-ternary phase diagrams and dye solubility tests. The microemulsions were gelled by the self-assembly of sorbitol derivatives as a gelator to form novel supramolecularly gelled microemulsions that can be used as the carrier of a dual-drug, such as hydrophilic 5-aminosalicylic acid and lipophilic curcumin. The effect of bovine serum albumin (BSA) on their release behavior depends upon the pH of the release media. In the case of pH 7.4, BSA inhibits the release of both drugs, but promotes their release if the pH is less than 7.4. We conclude that protein-modulated release is a promising strategy for dual-drug loading in the supramolecularly gelled microemulsions.

A novel drug carrier was synthesized through grafting polymerization of hydroxyethyl starch (HES) and d,l-lactide. By changing the molar ratio of HES and d,l-lactide, HES-g-PLA copolymers with different chain lengths of PLA can be obtained. Their chemical structures were characterized by FT-IR and 1H NMR. Through self-emulsification combined with solvent evaporation, HES-g-PLAs self-assembled into micelles with uniform sizes ranging from 65 to 130 nm, depending upon the chain length of PLA. In vitro release profiles of docetaxel-loaded HES-g-PLAs meet first-order release kinetics via a mechanism of diffusion and polymer chain relaxation. The size of the micelles and the amount of drug loading can be controlled by varying the chain length of PLA. Another significant result is that release rates of docetaxel can be also modulated by changing the chain lengths of the PLA segments.

1,3:2,4-di-O-benzylidene- D -sorbitol (DBS) can self-assemble into supramolecular nanofibers in the precursor of polyurethane followed by gelation. After UV-initiated polymerization, in situ supramolecular nanofibers reinforced polyurethane composites can be obtained. SEM studies indicate that the in situ formed supramolecular nanofibers can induce the composite interface at the molecular level, greatly improving interface compatibility of the fibers and matrices. Static and dynamic mechanical analysis indicated that the tensile strength of 12 wt% DBS nanofibers reinforced polyurethane was 2.8 times higher than that of pure polyurethane. Their breaking elongation was 2.5 times higher than that of conventional glass fibers reinforced polyurethane. In comparison with conventional fiber reinforced polymers, the utilizing of in situ formed supramolecular nanofibers not only reinforce, but also toughen the polymer matrices, and show the advantage of reducing the weight and maintaining transparency of the polymers.

We proposed a new electrochemical strategy to characterize the hydrophobic microenvironment of micellar-hybridized supramolecular gels. The micellar-hybridized systems consist of micelles formed from gemini surfactants and supramolecular gels formed by self-assembly of the gelator N,N-dibenzoyl-l-cystine (DBC). SEM images indicated that the microscopic morphology of micellar-hybridized DBC gels possessed a denser three-dimensional network structure. An important feature of micellar-hybridized supramolecular gels is the presence of hydrophobic microdomains within the systems. The interaction of Methylene Blue (MB) and the hydrophobic microdomains can be quantitatively characterized by the net positive shifts of the redox formal potential (E0′) and the change of peak currents (ip) obtained from the cyclic voltammograms of MB. ΔE0′ between the micellar-hybridized DBC gel and non-hybridized gel was much larger than that between the micellar solution and aqueous solution, implying that the alteration of hydrophobicity of microdomains in hybrid system. By comparing the apparent diffusion coefficients of MB in the varied systems, it is indicative that the apparent diffusion coefficients of MB can be also employed to characterize the hydrophobicity change of hybrid systems. The fluorescent spectra of 1,8-anilinonaphthalenesulfonic acid within the hybrid gels further verified the results of the cyclic voltammograms. It is suggested that the cyclic voltammograms are a facile and sensitive method to monitor the hydrophobic microenvironment of the micellar-hybridized supramolecular gels.

An aqueous mixture of sodium carbonate (Na2CO3) and sodium alginate (Na-ALG) was added dropwise into an aqueous solution of Ca(NO3)2, leading to the formation of calcium alginate (Ca-ALG) hydrogel beads. Meanwhile Na2CO3 as a pore-forming precursor was transformed in situ into CaCO3 nanoparticles (CaCO3 NPs). SEM images show that CaCO3 NPs aggregates with a size of ∼10 μm were uniformly distributed in the Ca-ALG hydrogel beads. After subsequent erosion using acetic acid, Ca-ALG hydrogel beads with a uniform microporous structure were obtained. The porosity and specific surface area of such in situ pore-formed hydrogel beads are 16 and 14 times higher than those of the beads prepared in the absence of Na2CO3. Additionally, their porous structure can be modulated by varying the amount of Na2CO3. The obtained porous Ca-ALG hydrogel beads were further immersed into an aqueous solution of AgNO3. Under UV irradiation, the Ag(+) ions adsorbed in the Ca-ALG were in situ reduced to Ag nanoparticles (Ag NPs). SEM and TEM images show that Ag NPs with a size of ∼10 nm were uniformly distributed in the matrix of the hydrogel beads. The loading amount of Ag in the beads can also be modulated by varying the amount of Na2CO3. Furthermore, the resultant Ca-ALG beads loaded with Ag NPs (Ag/Ca-ALG) were used as catalysts. Their catalytic activity was evaluated by using the reduction reaction of 4-nitrophenol as a model reaction. The rate constant of the reaction in the presence of dry porous Ag/Ca-ALG beads was found to be 36 times higher than that in the presence of beads prepared in the absence of Na2CO3. Such a high catalytic efficiency can be attributed to their porous structure and consequent high Ag-loading capacity.

Permanent and peripheral embolization is a requirement of embolic materials in the transcatheter arterial embolization of liver tumors. So far, it has been difficult to find materials that have both good flowability and high mechanical strength. In the present work, a temperature-sensitive p(N -isopropylacrylamide-co-butyl methylacrylate) (PIB) nanogel is explored as a novel blood-vessel-embolic material in the interventional therapy of liver tumors. With increasing temperature, the PIB nanogel dispersion sequentially exhibits three phase states; swollen gel, flowable sol, and finally shrunken gel. Iohexol, a nonionic X-ray contrast agent, increases the volume-phase transition temperature of the PIB nanogel and decreases the critical gelation concentration. Angiographical and histological studies on the embolization in the liver arteries of VX2 tumor-bearing rabbits indicate that the PIB nanogel dispersion mixed with iohexol (designated as PIB-I-6150) completely occludes all levels of blood vessels, including peripheral vessels. In addition, data on tumor volume, necrosis level, and the number of metastatic foci indicate that PIB-I-6150 has better peripheral embolization than Lipiodol. Experiments concerning cytotoxicity, hemolysis, histology, and liver function indicate that PIB-I-6150 has good biocompability.

Luminescence enhancement of terbium-ion prulifloxacin complexes (Tb(III)–PUFX) in supramolecular hydrogels formed by assembly of 1,3:2,4-di-O-benzylidene-D-sorbitol (DBS) was investigated by steady-state fluorescence, varying temperature fluorescence and time-resolved fluorescence. The luminescence images show that Tb(III)–PUFX were dispersed in the DBS gels. The luminescence intensity of Tb(III)–PUFX in the DBS gels was significantly increased in comparison with that in corresponding aqueous solutions. The varying temperature fluorescent spectra show that the luminescence intensity of Tb(III)–PUFX decreased with an increase in the temperature. This implies that the luminescence enhancement of Tb(III)–PUFX is related to the dissociation and the formation of the DBS assemblies. Time-resolved fluorescence measurements show slower rotational motion in DBS gels in comparison with that in the corresponding aqueous solutions. This may be ascribed to a unique microstructure of three-dimensional network formed by DBC aggregates, resulting in deactivation of the nonradiative relaxation. The images of field emission scanning electron microscopy and polarized optical microscopy indicate that the morphology of the DBS assemblies was not influenced upon addition of Tb(III)–PUFX to the DBS gels.

Bis(4-acylaminophenyl)methane (G1) and bis(4-acylaminophenyl)ether (G2) with varied acyl chains were found to be efficient gelators for the gelation of imidazole-based ionic liquids. The supramolecular gel electrolytes were formed via the self-assembly of these gelators in ionic liquids. The minimum gelator concentrations (MGCs) for the gelation of ionic liquids depend on the chemical structures of the gelators. The longer the acyl chains, the lower the MGCs. Polarized optical microscopy images of the ionic-liquid gels reveal the formation of spherical crystallites resulting from the fibrillar aggregates of the gelators. In addition, the phase transition temperatures of the ionic-liquid gels increase with an increase of the acyl chain length of the gelators. The impedance spectra of the ionic-liquid gels indicate that the temperature dependence of the conductivity follows the classical Arrhenius equation. The conductivities of ionic-liquid gels also decrease with an increase of the acyl chain length, but the differences in conductivities between the gels and corresponding ionic liquids are in one order of magnitude. The ionic-liquid gels possess a stable electrochemical window.

A new hydrogelator based on L-phenylalanine with a long hydrophobic chain and positively charged terminus was synthesized, and its gelation behavior in H2O was investigated. Polarized optical microscopy (POM), field emission scanning electron microscopy (FE-SEM), and X-ray diffraction (XRD) results indicate that the hydrogelator self-assembles into fibres-like aggregates which then lead to the formation of a hydrogel. 1H-NMR and CD spectra of hydrogels and aqueous solution revealed that intermolecular H-bonding between the amide groups was the driving force for gelation. A luminescence study, in which ANS (8-anilinonaphthalene-1-sulfonic acid) was used as a probe, indicated that the hydrophobic interactions between long chains were the driving force for gelation. Consequently, it was proved that the hydrogelator self-assembles into fibre-like aggregates and then forms supramolecular hydrogels through the H-bonding and hydrophobic interactions.