A Polymer Network Layer Containing Dually Anchored Ionic Liquids for Stable Lithium-Sulfur Batteries.

Lithium-sulfur (Li-S) batteries with high sulfur utilization, long-cycle life, and dendrite-free features hold great promise for the development of next-generation energy storage devices of high energy density. Considerable efforts have been committed to solving the polysulfide shuttle problem toward highly stable Li-S batteries. Here, a unique polymer network containing dually anchored ionic liquids (DA-PIL) is devolped to improve the cycling performance and coulombic efficiency of Li-S batteries. This DA-PIL electrolyte incorporates the amphiphilicity of both the polysulfides anion and lithium cation, creating an ionic function layer on polypropylene separator. Noteworthily, the DA-PIL network is "clean" in the sense that no free ionic specifies are introduced to the electrolyte system. The DA-PIL layer not only enables strong supression against polysulfide shuttling but simultaneously allows fast lithium transportation owing to cooperate electrostatic interaction among anchored cations and anions. The DA-PIL layer functionalized on a polypropylene separator can boost excellent stability of Li-S battery with >1600 h cycling test at 0.25 mA cm-2 . The Li-S cell with DA-PIL layer delivers a higher discharge capacity of 827.4 mAh g-1 at 1C. A discharge capacity of 630.6 mAh g-1 is retained after 1000 cycles.

Facile Fabrication of AIE-Active Fluorescent Polymeric Nanoparticles with Ultra-Low Critical Micelle Concentration Based on Ce(IV) Redox Polymerization for Biological Imaging Applications.

Fluorescent polymeric nanoparticles (FPNs) with aggregation-induced emission (AIE) property have received increasing attention and possess promising biomedical application potential in the recent years. Many efforts have been devoted to the fabrication methodologies of FPNs and significant advance has been achieved. In this contribution, a novel strategy for the fabrication of AIE-active amphiphilic copolymers is reported for the first time based on the Ce(IV) redox polymerization. As an example, ene group containing AIE-active dye (named as Phe-alc) is directly grafted onto a water soluble polymer polyethylene glycol (PEG) in H2 O/THF system under low temperature. Thus-obtained amphiphilic fluorescent polymers will self-assemble into FPNs with ultra-low critical micelle concentration, ultra-brightness, and great water dispersibility. Biological evaluation results suggest that the PEG-poly(Phe-alc) possess excellent biocompatibility and can be used for tracing their behavior in cells using confocal laser scanning microscope. These features make PEG-poly(Phe-alc) FPNs promising candidates for many biomedical applications, such as cell imaging, drug delivery vehicles, and targeted tracing. More importantly, many other functional groups can also be incorporated into these AIE-active FPNs through the redox polymerization. Therefore, the redox polymerization should be a facile and effective strategy for fabrication of AIE-active FPNs.

Ultrafast Preparation of AIE-Active Fluorescent Organic Nanoparticles via a "One-Pot" Microwave-Assisted Kabachnik-Fields Reaction.

The development of effective strategies for fabrication of fluorescent organic nanoparticles (FONs) with an aggregation-induced emission (AIE) feature has an important impact on the biomedical applications of these AIE-active FONs. In the current work, an ultrafast strategy for fabricating AIE-active FONs is developed through a "one-pot" microwave-assisted, catalysts-free, and solvent-free Kabachnik-Fields (KF) reaction for the first time. It is demonstrated that such organophosphorous-containing AIE-active block polymers can be synthesized within 2 min under air atmosphere through the microwave-assisted KF reaction. These polymers show amphiphilic properties and can self-assemble into mPEG-CHO-Phe-NH2 -DEP FONs, which display high water dispersibility and desirable optical properties. Biological evaluation results suggest that the mPEG-CHO-Phe-NH2 -DEP FONs exhibit low toxicity and are potential for biological imaging applications. More importantly, many other multifunctional AIE-active FONs can also be fabricated through the strategy described in this work owing to the universality of KF reaction. Besides, combined with the excellent properties of mPEG-CHO-Phe-NH2 -DEP FONs, it is believed that such microwave-assisted KF reaction shall be an effective route for designing various AIE-active nanomaterials for different biomedical applications.

Facile Fabrication of PEGylated Fluorescent Organic Nanoparticles with Aggregation-Induced Emission Feature via Formation of Dynamic Bonds and Their Biological Imaging Applications.

Driven by the high demand for sensitive and specific tools for optical imaging, fluorescent nanoprobes with various working mechanisms and advanced functionalities are flourishing at an incredible speed. This work reports the design and fabrication of aggregation-induced emission (AIE)-active fluorescent organic nanoparticles (FNPs) via forming dynamic phenyl borate between diol containing hydrophobic AIE dye (APD-PhCHO) and phenylboronic acid pendant hydrophilic polymers (PEGMA-VPBA) within 30 min. The final AIE-active APD-PhCHO-PEGMA-VPBA FNPs display high water dispersibility and strong fluorescence emission because of their amphiphilic properties and AIE feature. Biological evaluation suggests that APD-PhCHO-PEGMA-VPBA FNPs possess negative effect on HeLa cells and desirable optical properties for biological imaging. More importantly, phenyl borate is a dynamic bond with pH and glucose responsiveness. Furthermore, different functions can be designed and introduced into these AIE-active systems through adoption of different monomers for good applicability of free radical polymerization. Therefore, this work provides a novel platform for preparation of multifunctional AIE-active nanosystems with responsiveness for various biomedical applications.

Chiral stationary phases based on lactide derivatives for high-performance liquid chromatography.

Lactide is a natural and renewable lactone cyclic ester-containing intrinsic chiral center, providing an affordable natural compound that is potential for the development of chiral polymers. In this work, we reported two novel chiral stationary phases (CSPs) based on lactide derivatives, methylene lactide (MLA), for high-performance liquid chromatography (HPLC). By using free radical polymerization, chemically bonded CSPs of poly(methylene lactide) (PMLA) and side-chain modified PMLA by aminolysis (N-PMLA) can be prepared. Also, poly(l-lactic acid) (PLLA) was prepared as a control. The chiral resolution performance of the chromatographic columns was examined in both reversed-phase and normal-phase modes. PMLA and N-PMLA CSPs exhibited fairly good chiral recognition ability, whereas the separation ability of PLLA is much weaker. This work provides a new platform for the development of high-performance CSPs from affordable natural products.

Confined Self-Assemblies of Chiral Block Copolymers in Thin Films.

Self-assembly of chiral block copolymers (BCPs*) can give rise to ordered chiral nanostructures, that is, a helical phase (H* phase), via chirality transfer from the molecular level to mesoscale. In the present work, we reported the self-assembly of BCPs* under one-dimensional spatial confinement. The morphological dependence of self-assembled BCPs* on the molecular weights and the film thickness was investigated. As chiral nanostructures, the H* phase can be formed in bulk, nonchiral nanostructures that were observed in the thin films. Also, the topology effect of self-assembly of BCPs* was examined. The self-assembly of BCPs* with a star-shaped topology exhibited a distinct morphology compared with that of linear BCPs*. The present work provides new insight into the chirality transfer of macromolecules under spatial confinement.

Self-catalyzed photo-initiated RAFT polymerization for fabrication of fluorescent polymeric nanoparticles with aggregation-induced emission feature.

In recent years, the fluorescent polymeric nanoparticles (FPNs) with aggregation-induced emission (AIE) feature have been extensively exploited in various biomedical fields owing to their advantages, such as low toxicity, biodegradation, excellent biocompatibility, good designability and optical properties. Therefore, development of a facile, efficient and well designable strategy should be of great importance for the biomedical applications of these AIE-active FPNs. In this work, a novel method for the fabrication of AIE-active FPNs has been developed through the self-catalyzed photo-initiated reversible addition fragmentation chain transfer (RAFT) polymerization using an AIE dye containing chain transfer agent (CTA), which could initiate the RAFT polymerization under light irradiation. The results suggested that the final AIE-active FPNs (named as TPE-poly(St-PEGMA)) showed great potential for biomedical applications owing to their optical and biological properties. More importantly, the method described in the work is rather simple and effective and can be further extended to prepare many other different AIE-active FPNs owing to the good monomer adoptability of RAFT polymerization.

Recent progress and development on polymeric nanomaterials for photothermal therapy: a brief overview.

Photothermal therapy (PTT) is a rapidly expanding area which has attracted great research attention, and has emerged as a promising method for cancer treatment recently. PTT mainly relies on the local heating effect from photothermal agents (PTAs), which can transform the energy of light into heat. Various inorganic PTAs such as gold nanorods, carbon nanomaterials, layered transition metal dichalcogenides and various polymeric nanomaterials have been developed for PTT applications. However, inorganic PTAs are normally poorly biodegradable and potentially toxic. Polymeric PTAs possess many advantages in comparison with inorganic PTAs and have become the focus for PTT applications very recently. In this article, the recent advances and progress of polymers such as conjugated polymers and melanin-like polymers for PTT applications are introduced. The future direction, challenges and potential development of polymeric PTAs for efficient PTT are also addressed. The objective of this review is to give a brief overview of this emerging field to polymer chemists and material scientists.

Fabrication, self-assembly and biomedical applications of luminescent sodium hyaluronate with aggregation-induced emission feature.

Organic dyes with aggregation-induced emission (AIE) feature have recently attracted much research attention for biomedical applications due to their inimitable optical superiority. Although many reports have demonstrated for fabricating AIE-active nanoprobes, the synthesis of AIE-active natural polymers is still very limited. In this work, fluorescent organic nanoparticles (FONs) with AIE feature have been prepared through formation of Schiff base interaction between amino-terminated AIE dye (PhE) and oxidation sodium hyaluronate (OSH). The final copolymers (denoted as PhE-OSH) were characterized by means of 1H nuclear magnetic resonance spectroscopy, transmission electron microscopy, fluorescent spectroscopy and X-ray photoelectron spectroscopy. The potential of using PhE-OSH in biomedical applications were examined by cell viability assay as well as confocal imaging capability. Results suggested that PhE can facilely conjugate with OSH through formation of Schiff base. The synthesized PhE-OSH FONs exhibited well dispersibility in aqueous solution, small size, strong fluorescence and good biocompatibility. Taken together, we developed a novel strategy for fabrication of AIE-active FONs, which showed great potential for biomedical applications.

Surface grafting of Eu3+ doped luminescent hydroxyapatite nanomaterials through metal free light initiated atom transfer radical polymerization for theranostic applications.

We reported a simple and efficient method to prepare the hydrophilic luminescent HAp polymer nanocomposites through the combination of ligand exchange and metal free light initiated surface-initiated atom transfer radical polymerization (SI-ATRP) using 10-phenylphenothiazine (PTH) as organic catalyst and 2-methacryloyloxyethyl phosphorylcholine (MPC) and itaconic acid (IA) as monomers. The biological imaging and drug delivery performance of HAp-poly(MPC-IA) nanorods were examined to evaluate their potential for biomedical applications. Results suggested that hydrophilic HAp-poly(MPC-IA) nanorods can be successfully prepared. More importantly, the HAp-poly(MPC-IA) exhibited excellent water dispersibility, desirable biocompatibility and good performance for biological imaging and controlled drug delivery applications. As compared with other controlled living polymerization reactions, the metal free light initiated SI-ATRP displayed many advantages such as easy for handle, mild reaction conditions, toxicity and fluorescence quenching from metal catalysts. Therefore, we believe that this strategy should be a useful and effective strategy for preparation of HAp nanomaterials for biomedical applications.

Facile synthesis of polymeric fluorescent organic nanoparticles based on the self-polymerization of dopamine for biological imaging.

Polymeric fluorescent organic nanoparticles (polymer-FONs) have raised considerable research attention for biomedical applications owing to their advantages as compared with fluorescent inorganic nanoparticles and small organic molecules. In this study, we presented an efficient, facile and environment-friendly strategy to produce polymer-FONs, which relied on the self-polymerization of dopamine and polyethyleneimine (PEI) in rather mild conditions. To obtain the final polymer-FONs, aldehyde group-containing copolymers (named as poly(UA-co-PEGMA)) were synthesized by reversible addition-fragmentation chain-transfer polymerization using polyethylene glycol methyl ether methacrylate (PEGMA) and 1-undecen-10-al (UA) as monomers. The dopamine was conjugated onto poly(UA-co-PEGMA) through a multicomponent reaction between UA and dopamine to obtain poly(UA-co-PEGMA)-DA, which was further utilized for preparation of polymer-FONs through self-polymerization of dopamine and PEI. 1H nuclear magnetic resonance, Fourier transform infrared spectroscopy, transmission electron microscopy and fluorescence spectroscopy were employed to characterize the structure, morphology, compositions and optical properties of these polymer-FONs. Cell viability and cell uptake behavior results suggested that these polymer-FONs possess good biocompatibility and can be potentially utilized for biomedical applications. More importantly, the method can be also applied to fabricate many other multifunctional polymer-FONs with great potential for biomedical applications.

Synthesis and cell imaging applications of amphiphilic AIE-active poly(amino acid)s.

The poly(amino acid)s based biomaterials have attracted great research attention over the past few decades because of their biocompatibility, biodegradability and well designability. Although much progress has achieved in the synthesis and biomedical applications of poly(amino acid)s, the synthesis of luminescent poly(amino acid)s has been rarely reported. In this work, novel amphiphilic luminescent poly(amino acid)s with aggregation-induced emission (AIE) feature have been synthesized by a new approach of controlling N-carboxy anhydride (NCA) ring-opening polymerization, in which hydrophobic 2-(4-aminophenyl)-3-(10-hexadecyl-4H-phenothiazin-3-yl)acrylonitrile (Phe-NH2) with AIE feature was used as initiator and hydrophilic oligomeric glycol functionalized glutamate (OEG-glu) NCA was acted as monomer. The successful synthesis of final Phe-OEG-Pglu polymers was confirmed by different characterization techniques. Phe-OEG-Pglu polymers possess amphiphilic properties and can self-assemble into luminescent polymeric nanoparticles (LPNs). Based on cellular imaging experiments, we demonstrated that Phe-OEG-Pglu LPNs have great potential for bio-imaging applications due to their attractive properties including strong fluorescence intensity, great water dispersibility, excellent biocompatibility and high cellular uptake efficiency.

Photo-induced surface grafting of phosphorylcholine containing copolymers onto mesoporous silica nanoparticles for controlled drug delivery.

Surface modification of mesoporous silica nanoparticles (MSNs) with functional polymers has become one of the most interest topics over the last decade. Among various surface modification strategies, surface-initiated atom transfer radical polymerization (ATRP) has been regarded as one of the most effective methods. However, the typical ATRP strategy is relied on the transition metal ions and their organic ligands as the polymerization catalyst systems. In this work, a novel surface-initiated ATRP method was established for surface functionalization of MSNs using 10-Phenylphenothiazine (PTH) as the catalyst, 2-methacryloyloxyethyl phosphorylcholine (MPC) and itaconic acid (IA) as the monomers. We demonstrated that photo-induced ATRP is very effective for preparation of polymer functionalized MSNs (MSNs-NH2-poly(IA-co-MPC)). More importantly, MSNs-NH2-poly(IA-co-MPC) displayed well water dispersity, low cytotoxicity, high loading capability and controlled release behavior towards cisplatin. Furthermore, the method based on photo-induced surface-initiated ATRP could effectively overcome the drawbacks of conventional ATRP, which may involve in the residue of transition metal ions, high polymerization temperature, long polymerization term and complex experimental procedure. Therefore, this strategy described above is of great interest for fabrication of multifunctional polymer composites for various applications.

Rapid preparation of branched and degradable AIE-active fluorescent organic nanoparticles via formation of dynamic phenyl borate bond.

The fluorescent organic nanoparticles (FNPs) with aggregation-induced emission (AIE) feature have received increasing attention for their advanced optical properties. Although many efforts have been devoted to the fabrication and biomedical applications of AIE-active FNPs, the preparation of branched AIE-active FNPs with degradability through formation of dynamic bonds have rarely been reported. In this work, branched AIE-active FNPs were fabricated via dynamic linkage of hydrophobic hyperbranched and degradable Boltorn H40 (H40) with phenylboronic acid terminated AIE dye (PhB(OH)2) and mPEG (mPEG-B(OH)2), which relied on a facile one-pot strategy between phenylboronic acid and diol group of H40. The branched H40-star-mPEG-PhB(OH)2 FNPs were characterized using nuclear magnetic resonance spectroscopy, Fourier transform infrared spectroscopy, and fluorescence spectroscopy. Benefiting from their highly branched structure and amphiphilic properties, H40-star-mPEG-PhB(OH)2 could self-assemble into micelles and emit strong orange-red fluorescence. More importantly, cell viability results demonstrated that H40-star-mPEG-PhB(OH)2 FNPs showed good biocompatibility and promising candidates for bio-imaging. Taken together, we developed a one-pot strategy for preparation of branched AIE-active FNPs through the formation of dynamic phenyl borate. The resultant H40-star-mPEG-PhB(OH)2 FNPs should be promising biomaterials for different applications for biodegradability of H40 and responsiveness of phenyl borate.

Surface functionalized SiO2 nanoparticles with cationic polymers via the combination of mussel inspired chemistry and surface initiated atom transfer radical polymerization: Characterization and enhanced removal of organic dye.

Monodispersed SiO2 particles functionalized with cationic polymers poly-((3-acrylamidopropyl)trimethylammonium chloride) (PAPTCl) were prepared using mussel inspired surface modification strategy and surface initiated atom transfer radical polymerization (SI-ATRP). Fourier transform infrared spectroscopy, transmission electron microscope, thermogravimetric analysis, X-ray photoelectron spectroscopy, and zeta potential were employed to characterize these SiO2 samples. The adsorption performance of the functionalized SiO2 (donated as SiO2-PDA-PAPTCl) towards anionic organic dye Congo red (CR) was investigated to evaluate their potential environmental applications. We demonstrated that the surface of SiO2 particles can be successfully functionalized with cationic PAPTCl. The adsorption capability of as-prepared SiO2 was found to increases from 28.70 and 106.65mg/g after surface grafted with cationic polymers. The significant enhancement in the adsorption capability of SiO2-PDA-PAPTCl is mainly attributed to the introduction of cationic polymers. More importantly, this strategy is expected to be promising for fabrication of many other functional polymer nanocomposites for environmental applications due to the universality of mussel inspired chemistry and well designability and good monomer adaptability of SI-ATRP.

One-step synthesis, self-assembly and bioimaging applications of adenosine triphosphate containing amphiphilies with aggregation-induced emission feature.

Amphiphilic molecules with aggregation-induced emission (AIE) characteristics have attracted intensive interest for biological imaging applications for their self-assembly into nanostructures and obvious enhanced fluorescence intensity in aqueous solution. Although many AIE-active fluorescent organic nanoparticles (FONs) have been fabricated recently, the direct linkage of hydrophilic small molecules and hydrophobic AIE dyes has rarely been reported. In this work, we reported a one-pot strategy for preparation of adenosine triphosphate (ATP) containing molecules that conjugated the amino group of ATP and aldehyde-terminated AIE dye (PhCHO) based on mercaptoacetic acid locking imine (MALI) reaction. These AIE-active ATP-PhCHO showed amphiphilic properties and could self-assemble into micelles, which displayed high water dispersibility, strong yellow fluorescence, good biocompatibility and biological imaging capability. These advantages make ATP-PhCHO FONs promising for biomedical applications.

Recent developments in polydopamine: an emerging soft matter for surface modification and biomedical applications.

After more than four billion years of evolution, nature has created a large number of fascinating living organisms, which show numerous peculiar structures and wonderful properties. Nature can provide sources of plentiful inspiration for scientists to create various materials and devices with special functions and uses. Since Messersmith proposed the fabrication of multifunctional coatings through mussel-inspired chemistry, this field has attracted considerable attention for its promising and exiciting applications. Polydopamine (PDA), an emerging soft matter, has been demonstrated to be a crucial component in mussel-inspired chemistry. In this review, the recent developments of PDA for mussel-inspired surface modification are summarized and discussed. The biomedical applications of PDA-based materials are also highlighted. We believe that this review can provide important and timely information regarding mussel-inspired chemistry and will be of great interest for scientists in the chemistry, materials, biology, medicine and interdisciplinary fields.

Facile fabrication of amphiphilic AIE active glucan via formation of dynamic bonds: self assembly, stimuli responsiveness and biological imaging.

Fluorescent organic nanoparticles (FONs) with aggregation induced emission (AIE) properties have recently emerged as one of the most promising luminescent nanomaterials for biomedical applications due to their unique AIE feature. In this study, we reported the preparation of AIE active FONs through mixing AIE dye (TPE-CHO), 3-aminobenzeneboronic acids (ABBA) and glucan in one-pot. ABBA acted as a molecular "bridge" to conjugate TPE-CHO with glucan via formation of a Schiff base and phenyl borate. The resultant products (Glu-TPE FONs) showed amphiphilic properties and could self-assemble into nanoparticles in an aqueous solution. Glu-TPE FONs showed strong luminescence intensity and high water dispersibility because of the AIE properties of TPE-CHO and hydrophilic nature of glucan. To examine the biomedical application potential of glucan-AIE FONs, the responsiveness, biocompatibility and cell uptake behavior of Glu-TPE FONs were subsequently examined. We demonstrated that Glu-TPE FONs possess good biocompatibility and can be potentially used for biological imaging applications. More importantly, it is well known that the Schiff base and phenyl borate can respond to pH and glucose. Therefore, Glu-TPE FONs can be used for the fabrication of multifunctional biomaterials with stimuli responsiveness.

Fabrication and biomedical applications of AIE active nanotheranostics through the combination of a ring-opening reaction and formation of dynamic hydrazones.

Aggregation-induced emission (AIE) dyes based on fluorescent organic nanoparticles (FONs) have attracted increasing interest over the past few years. However, the biomedical applications of AIE dyes based on FONs for simultaneous biological imaging and therapeutic applications have rarely been reported thus far. In this study, an amino group terminated phenothiazine (named as ATPHE) with AIE features and red fluorescence was synthesized and utilized for the fabrication of AIE active FONs via a facile one-pot strategy, which relied on the ring-opening reaction between ATPHE and an anhydride containing compound. Then, the keto group of the AIE active polymeric intermediate was subsequently conjugated with hydrazide terminated polyethylene glycol (HTPEG) through the formation of hydrazone bonds. These amphiphilic AIE active copolymers are readily self-assembled into nanoscale particles in an aqueous solution, which resulted in strong luminescence and good water dispersibility of the final HTPEG@ATPHE-co-BTDA FONs. The excellent physicochemical and biological properties of HTPEG@ATPHE-co-BTDA FONs give them high potential for biological imaging and controlled drug delivery applications. Taken together, we developed a simple strategy for the fabrication of AIE active nanoparticles, which are promising for biological imaging and controlled drug delivery.