Intercalation chemistry engineering strategy enabled high mass loading and ultrastable electrodes for High-Performance aqueous electrochemical energy storage devices.

Aqueous electrochemical energy storage devices (AEESDs) are considered one of the most promising candidates for large-scale energy storage infrastructure due to their high affordability and safety. Developing electrodes with the merits of high energy density and long lifespan remains a challenging issue toward the practical application of AEESDs. Research attempts at electrode materials, nanostructure configuration, and electronic engineering show the limitations due to the inherent contradictions associated with thicker electrodes and ion-accessible kinetics. Herein, we propose an intercalation chemistry engineering strategy to enhance the electrolyte ion (de)intercalation behaviors during the electrochemical charge-discharge. To validate this strategy, the prototypical model of a high-mass-loading MnO2-based electrode is used with controlled intercalation of Na+ and H2O. Theoretical and experimental results reveal that an optimal content of Na+ and H2O on the MnO2-based electrode exhibits superior electrochemical performance. Typically, the resultant electrode exhibits an impressive areal capacitance of 1551 mF/cm2 with a mass loading of 9.7 mg/cm2 (at 1 mA/cm2). Furthermore, the assembled full-cell with obtained MnO2-based electrode delivers a high energy density of 0.12 mWh/cm2 (at 20.02 mW/cm2) and ultra-high cycling stability with a capacitance retention percentage of 89.63 % (345 mF/cm2) even after 100,000 cycles (tested over 72 days).

Phosphorylated dendronized poly(amido amine)s as protein analogues for directing hydroxylapatite biomineralization.

Dendronized poly(amido amine)s (DPs) bearing tri-phosphate or bis-phosphonate peripheral groups are synthesized. These worm-like DPs can template the formation of BMSCs adhesive hydroxylapatite (HA) on the nano-scale, or self-assemble into mineral-collecting microfibers on the micro-scale, exhibiting similar functions of non-collagenous proteins (NCPs) in the natural biomineralization process of HA.

Multifunctional hydrogels based on ß-cyclodextrin with both biomineralization and anti-inflammatory properties.

In this study, a series of carboxylated hydrogels are synthesized using ß-cyclodextrin, epichlorohydrin and succinic anhydride. It is found that the carboxyl groups on the ß-cyclodextrin hydrogels could facilitate the biomineralization process in the simulated body fluid. The new generated minerals are apatite and similar to that of bones. Meanwhile, the carboxylated ß-cyclodextrin hydrogels can also load and release anti-inflammatory drug (using indomethacin as a model) in a controlled manner during the biomineralization process for 28 days. The carboxylated ß-cyclodextrin hydrogels also have low cytotoxicity and are promising for bone tissue engineering.

Controlled insulin release from glucose-sensitive self-assembled multilayer films based on 21-arm star polymer.

A glucose-sensitive multilayer film was fabricated by the layer-by-layer (LbL) assembly method with positively charged 21-arm poly[2-(dimethylamino)ethyl methacrylate] (star PDMAEMA) and negatively charged insulin and glucose oxidase (GOD) in the form of {(Star PDMAEMA/Insulin)(4) + (Star PDMAEMA/GOD)(4) + Star PDMAEMA}. The multilayer film shows an on-off regulation of insulin release in response to stepwise glucose challenge in vitro. It is found that the unique structure of star PDMAEMA and interdiffusion of charged insulin are the main factors to control the on-off status of the film. Reversible surface morphology transitions of the multilayer film were also observed, revealing a phase separation and large-scale reorganization process. Furthermore, the multilayer film could continuously release enough insulin in vivo after being subcutaneously implanted in streptocozotin-induced diabetic rats and reduce the blood glucose level for at least two weeks. It is indicated that such system may have substantial potential as a glucose-sensitive carrier for insulin due to its distinct mechanism.

Effective protection and controlled release of insulin by cationic beta-cyclodextrin polymers from alginate/chitosan nanoparticles.

In an alginate/chitosan nanoparticle system, insulin was protected by forming complexes with cationic beta-cyclodextrin polymers (CPbetaCDs), which were synthesized from beta-cyclodextrin (beta-CD), epichlorohydrin (EP) and choline chloride (CC) through a one-step polycondensation. Due to the electrostatic attraction between insulin and CPbetaCDs, as well as the assistance of its polymeric chains, CPbetaCDs could effectively protect insulin under simulated gastrointestinal conditions. The nanoparticles have their mean size lower than 350 nm and can load insulin with the association efficiency (AE) up to 87%. It is notable that the cumulative insulin release in simulated intestinal fluid was significantly higher (40%) than that without CPbetaCDs (18%) because insulin was mainly retained in the core of the nanoparticles and well protected against degradation in simulated gastric fluid. Far-UV circular dichroism analysis also corroborated the preservation of insulin structure during the nanoparticle preparation and release process.

Study of branched cationic beta-cyclodextrin polymer/indomethacin complex and its release profile from alginate hydrogel.

A series of branched cationic beta-cyclodextrin polymers (CPbetaCDs) with designed chemical structures were synthesized from beta-cyclodextrin (beta-CD), epichlorohydrin (EP) and choline chloride (CC). Indomethacin (IDM), an anionic drug, was chosen as a model drug to evaluate the drug loading capacities of CPbetaCDs. The formation of IDM-CPbetaCD complex was confirmed by (1)H NMR and DSC. Phase solubility studies and Job plots indicated that CPbetaCDs can solubilize IDM up to 100 times of its intrinsic solubility in a 1:1 complexation form. Mechanism studies with the help of adamantane revealed that the effective complexation is a combination of inclusion complexation, charge interaction and hydrophobic interaction. In addition, IDM-CPbetaCDs loaded alginate hydrogels were prepared and obtained controllable release profile in dissolution tests. The tunable structures of CPbetaCDs make them promising drug carriers with superior drug loading capacities and controllable drug release abilities.