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Interventional embolization and minimally invasive thermal ablation are common clinical methods for treatment of unresectable solid tumors, but they both have many insurmountable disadvantages. Inspired by pH-responsive drug delivery systems, we report the tumor microenvironment-gelled nanocomposites with poly[(l-glutamic acid

Inspired by the mussel foot protein and chitosan-based macromolecular adhesives, a series of chitosan-graft-polypeptides were synthesized by ring-opening polymerization of three N-carboxyanhydrides (NCAs) - 3,4-dihydroxyphenylalanine-N-carboxyanhydride (DOPA-NCA), cysteine-NCA (Cys-NCA) and arginine-NCA (Arg-NCA) - using partial-NH2-protected chitosan as an initiator. These copolymers demonstrated good biodegradability and low cytotoxicity. The results of lap-shear adhesion test showed that the maximum lap-shear adhesion strength on the porcine skin and aluminum sheet were 195.97 ± 21.1 kPa and 3080 ± 320 kPa, respectively, and the maximum tensile adhesion strength on bone was 642.70 ± 61.1 kPa. The rat experiment in vivo showed that these copolymers exhibited good hemostatic performance and can promote the healing of skin wound and bone fracture. It is expected that thesecopolymeric adhesives will have broad applications in hemostasis and soft tissue adhesions.

To assess the mechanism and milder conditions for amines to imines, UiO-66-NH2 was chosen as an efficient photocatalyst for the transformation under light irradiation. A series of experiments for the catching of the active species were performed, and it was proved that holes (h+) and superoxide radicals ( O2−) were involved when the reaction was performed under air. The reaction also occurred because of the presence of nitrogen-centered radical cations and carbon-centered radicals, which were induced by photogenerated hole (h+) with considerable conversion and selectivity under anaerobic conditions. Our experiments revealed that the catalyst can be recycled for four times.

Due to the uncontrollable anticoagulant activity and limited source, Heparin, which is commonly used in clinical anticoagulation therapies, faces the risk of spontaneous bleeding and thrombocytopenia. Herein, a series of anionic poly(amino acid) s poly ( l -Serine-ran-L-Glutamic acid-ran-L-Cysteine-SO3) (PSEC-SO3) were prepared by the controlled Ring Opening Polymerization (ROP) of N-Carboxyanhydrides (NCAs). The anticoagulant activities of PSEC-SO3 can be regulated by simply adjusting the feeding ratio of monomers. In vitro tests show that these polypeptides can effectively prolong the Activated Partical Thromboplastin Time (APTT) and inhibit Factor IIa and Factor Xa, but has no significant effect on Prothrombin Time (PT) and Thrombin Time (TT), which indicates that PSEC-SO3 mainly act on the intrinsic pathway. In summary, the activity-tunable heparin-like polypeptides are expected to have good application prospects in the anticoagulant field.

A series of hyperbranched, thermo-responsive and mussel-inspired polypeptides were synthesized and used for surgical adhesion, hemostasis and interventional embolization. These polypeptides showed excellent tissue-adhesive properties according to adhesive strength tests on porcine skin and bone in vitro, where the maximum lap-shear adhesion strength on porcine skin was 114.5 kPa and the maximum tensile adhesion strength on bone was 786 kPa. In vivo animal experiments indicated that these polypeptides exhibit superior hemostatic properties and healing effects in skin incisions and osteotomy gap; the skin incision healing and osteotomy gap remodeling were completed in all rats after 14 and 60 days, respectively. In vivo evaluation of the embolization ability of these polypeptides was performed on rabbit kidney models, resulting in successful occlusion of renal arteries, which led to gross ischemic changes in the embolized kidneys up to 16 days. A trial embolization procedure on H22 tumor-bearing rat models also confirmed the gelability of these polypeptides in tumor arteries, which might cause damage to embolized tumors. Therefore, these polypeptides are expected to be good candidates as surgical tissue adhesives, antibleeding materials, and effective embolic materials.

Fluorescence imaging, especially specific organelle imaging, has become a significant technology to comprehending cell transplantation, migration, division, fusion, and lysis. In this paper, we designed and synthesized a water soluble and fluorescent polymer named as Poly(AA-TPA-d), which was pH-responsive by the fluorescence channel due to the presence of poly acrylic acid as the polymer backbone. The research results demonstrated that Poly(AA-TPA-d) exhibits novel aggregation-induced-emission (AIE) property. Additionally, due to the hydrogen bond formation and C=O···π interactions between methyl acrylate groups, Poly(AA-TPA-d) was of excellent hydrogel formation ability. Moreover, Poly(AA-TPA-d) displayed good bio-compatibility with the living MPC5 cells and highly specific cytoplasm-targeting ability by MTT assay and cell staining experiment respectively.

This study investigates the photocatalytic reduction of nitroaromatic compounds upon visible light over novel Ce-doped UiO-66/graphene nanocomposites. Ce doped UiO-66 nanostructures and the corresponding graphene hybridized nanocomposites were facilely synthesized by means of one step solvothermal reaction. It has been demonstrated that produced nanocomposites could be used as highly efficient and chemical stable photocatalysts for the reduction of nitroaromatic compounds under visible irradiation and ambient conditions. Compared with the bare UiO-66, Ce-UiO-66/GR distinctly enhanced photocatalytic activity. Ce as “mediator” introduced into the MOFs materials can greatly improve the electron transfer across the interface between grephene and the UiO-66 and further improve the visible light driven photoactivity. This is an effective strategy for the development of high photocatalytic activity MOFs based materials.

In this study, thermoresponsive and mussel-inspired polypeptides were synthesized using ring-opening polymerization of α-amino acid derivatives of N-carboxyanhydride (NCA). The tissue adhesive properties of these polypeptides were evaluated using in vitro adhesive strength tests on porcine skin and bone. The results indicated that the species of the functional polypeptide side groups and the adhesive temperature have a significant influence on the adhesion strength. The maximum of the lap-shear adhesion strength on porcine skin was 101.2 kPa, and the maximum of tensile adhesion strength on bone was 603 kPa. The in vivo antibleeding activity and tissue adhesive ability were also evaluated using a rat model. These polypeptides exhibited superior hemostatic properties and healing effects in the skin incision and osteotomy gap, and the skin incision healing and osteotomy gap remodeling were completed in all rats after 2–9 weeks. These polypeptides are expected to be good candidates for surgical tissue adhesiv...

There are a lot of demands to develop abundant superior properties of aggregation-induced emission (AIE) polymers used in the aggregation state. Here we report a practical and versatile approach for the preparation of AIE polymers by conventional free radical polymerization. As an initiator, TPE-AZO has an excellent ability to initiate polymerization of various kinds of vinyl monomers to obtain AIE functional materials. It was found that TPE polymers emit multiple colors with wavelengths ranging from 370 to 482 nm, and they also exhibit the advantages of combining the AIE characteristic with unique properties of polymers. The fluorescence properties of temperature-sensitive TPE-PNIPAM, pH-sensitive TPE-PMAA, and counterion-sensitive TPE-PMETAC were investigated, and the results indicated that all of the responsive behaviors of the three TPE polymers were related to the change in fluorescence. Our versatile approach would provide a platform to fabricate AIE polymers with various superior properties using t...

In this work, we fabricated a novel triphenylamine-derivative (DNDT)-modified nanographene oxide by following a simple gram-scale method. The product showed interesting optical properties and good potential for use in bioimaging applications. This fluorescent carbon material could be readily internalized by HepG2 cells and was clearly visualized to accumulate mainly in the nucleus.

The effective polymerization process is very desirable in the field of macromolecule science. In this study, we present a facile synthetic method via aldol addition and condensation (AAC) that leads to the formation of fluorescent linear and branched polymers by cross coupling triphenylamines (TPA) and cyclohexanones (CYC) via CC bond formation. The methodology has the advantage of easy operations, mild reaction conditions, and high yield. Via the analysis of NMR, FT-IR, GPC, PL, UV, SEM, and theoretical calculation, the structure, physical properties, and optical behaviors of both polymers were well-characterized. The understanding of cell transplantation, migration, division, fusion, and lysis is a very challenging task. In this study, the linear polymer (LP) exhibits excellent biocompatibility and low cytotoxicity, which can be readily internalized by living cells in a noninvasive manner. The images of MPC5 cells indicate that LP can be a promising emissive fluorescence probe for bioimaging application.

A novel class of phenylene-(poly)ethynylene-based dye Sensor 1 with remarkable properties of solvatochromism has been designed and synthesized. A long, coplanar and asymmetry electron-rich π-conjugated structure endows Sensor 1 with maximum solvatochromic effect by intramolecular charge-transferstates (ICT). More importantly, The dye is found to serve as supersensitive fluorescent indicator for the quantitative detection of low-level water content in five common organic solvents with low detection limits. Furthermore, the development of easy-to-prepare test papers provides a convenient and reliable approach to qualitatively monitor water in organic solvents by naked eye. Results in this work not only provide a successful molecular design concept of the novel sensitive solvatochromic dye sensor for water in organic solvents, but also develop practical applications of the linear π-conjugated molecule bearing phenylene-(poly)ethynylene in chemosensor field.

In this study, we present a simple and green approach to fabricate a magnetic halloysite nanotube (MHNT) supported Au nanoparticle (NP) composite (MHNTs–PDA–Au) with a polydopamine functional coating for highly effective and recyclable catalysis. The fabrication of MHNTs–PDA–Au involves decoration of Fe3O4 NPs on HNTs via a one-step co-precipitation method, deposition of a polydopamine layer on the MHNTs and subsequent in situ reduction of Au NPs via polydopamine chemistry. All the processes are simple and eco-friendly without use of additional toxic reagents and complicated treatment. The obtained MHNTs–PDA–Au composite exhibits excellent and versatile catalytic activity toward the reduction of various nitrobenzene derivatives and methylene blue dye when only trace amounts of Au catalyst are used. In addition, the catalytic system can be easily recycled for several cycles based on its good magnetic properties. The synergistic combination of MHNTs, polydopamine coating and metal NPs offers a versatile platform for design of natural HNT based composite materials and will expand the applications of HNTs in heterogeneous catalysis, water purification and green chemistry.

The incorporation of L-3,4-dihydroxyphenylalanine (L-DOPA) residues in mussel-like biomimetic copolymers has drawn great attention due to their adhesive properties. In this work, a series of temperature-sensitive and hyperbranched poly(amino acid)s containing different functional side groups (catechol, guanidyl, mercapto and double bond) were designed and synthesized by the ring-opening polymerization of N-carboxy-α-amino acid anhydride (NCA), using a temperature-sensitive and multi-hydroxyl end pluronic L-31 as the initiator in this process. The tissue adhesive properties of these copolymers were evaluated by tensile strength tests on wet pork skin. We found that the topological structure, side groups of copolymers, adhesive temperature and cure time had influence on the wet adhesive strength, especially side groups. While only L-DOPA was incorporated into copolymeric chains, the wet adhesive strength was about 106 kPa. With guanidyl, mercapto and double bonds incorporated into copolymeric chains, an obvious increase in the wet adhesive strength was observed. Additionally, the wet adhesive strength improved by about 20 kPa at body temperature (37 °C) as compared to that at room temperature (25 °C). Meanwhile, we found that it has good biocompatibility and degradability through its cytotoxicity and degradation tests.

In this study, we present a practical approach to tune the fluorescence of AIEgen (the luminogens exhibiting AIE attributes) based on counterion-sensitive polyelectrolyte microspheres. The tunable fluorescence is induced by counterion-driven interactions in polyelectrolyte microspheres by a simple exchange of the counterions. The effects of different types of opposite counterions on the fluorescent properties of a new polyelectrolyte tetraphenylethene-graft-poly[2-(methacryloyloxy)-ethyltrimethylammonium chloride] (TPE–PMETAC), which was synthesized by Atom Transfer Radical Polymerization (ATRP) using a TPE derivative containing four arms as an initiator, were systematically investigated. For cationic microspheres with quaternary ammonium groups, the fluorescence intensity progressively increased according to the counterion series Cl− < ClO4− < PF6− < TFSI−, which is in accord with the ability of exchanged hydrophilic Cl− by hydrophobic anions in the order of ClO4− < PF6− < TFSI−. The mechanism of tuning fluorescence was determined by dynamic light scattering (DLS), zeta-potentials and scanning electron microscopy (SEM). We proved that the size of the microspheres and electrostatic repulsive forces between the microspheres were decreased by the addition of counterions due to the hydrophobic-induced collapse of the surfaces of the microspheres. As a result, the obvious increase in the fluorescence of AIEgen was obtained based on the aggregation of microspheres.

Inspired by marine mussel adhesive proteins, polymers with catechol side groups have been extensively explored in industrial and academic research. Here, Pluronic L-31 alcoholate ions were used as the initiator to prepare a series of polypeptide-Pluronic-polypeptide triblock copolymers via ring-opening polymerization of l-DOPA-N-carboxyanhydride (DOPA-NCA), l-arginine-NCA (Arg-NCA), l-cysteine-NCA (Cys-NCA), and ε-N-acryloyl lysine-NCA (Ac-Lys-NCA). These copolymers demonstrated good biodegradability, biocompatibility, and thermoresponsive properties. Adhesion tests using porcine skin and bone as adherends demonstrated lap-shear adhesion strengths up to 106 kPa and tensile adhesion strengths up to 675 kPa. The antibleeding activity and tissue adhesive ability were evaluated using a rat model. These polypeptide-Pluronic copolymer glues showed superior hemostatic properties and superior effects in wound healing and osteotomy gaps. Complete healing of skin incisions and remodeling of osteotomy gaps were observed in all rats after 14 and 60 days, respectively. These copolymers have potential uses as tissue adhesives, antibleeding, and tissue engineering materials.

A novel thermosensitive adhesive was synthesized by the esterification reaction of multihydroxyl Pluronic L-31 with 3,4-dihydroxy-l-phenylalanine and l-arginine. Pluronic L-31–DOPA–arginine derivative (PDA) gels, rapidly formed in situ with horseradish peroxidase and hydrogen peroxide, were used to explore the performance of efficient tissue adhesives. The results of their adhesive strength on porcine skin demonstrate that the structure of the polymers and temperature influenced the adhesiveness to tissue of the polymers. Compared with the PDAs at 25 °C, the PDAs at 37 °C showed superior adhesive strength. The attractive performance of the PDA gels were demonstrated by this study's results, which suggest biomedical applications in tissue-adhesive devices in the future. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 44729.

Click chemistry is employed to couple two β-cyclodextrins at both ends of azobenzene moiety yielding dumbbell-shaped amphiphiles (AZO-β-CD dimer) constructed by rigid aromatic building blocks as “body”, and hydrophilic cyclodextrins as “head” with almost quantitative yield and purity. Bulk aggregates formed by the self-assembly of the supraamphiphiles through π–π stacking and hydrophobic effect are observed. Meanwhile, the rationally designed polyesters, named as AZO-PCL with controllable molecular weights and low polydispersities, are successfully synthesized by ring-opening polymerization of e-caprolactone in the presence of p-aminoazobenzene as initiator. In the aqueous phase, very stable spherical particles are formed by host–guest interactions between AZO-β-CD and AZO-PCLs; the spherical aggregates inherit the photo-responsiveness of azobenzene. The detailed aggregation and disaggregation behaviors are fully investigated by TEM, SEM, NMR, 2D NOESY, IR, UV and XRD measurements. Compared to the previous works, our newly developed system can be fabricated with more readily manners, avoiding tedious synthetic process; the reversible and dynamic nature of the non-covalent interactions also can be modulated alternatively by UV or visible light. Thus, such dumbbell-shaped supra-amphiphiles are of great potential applications in the controlled delivery systems. Copyright © 2014 John Wiley & Sons, Ltd.

A series of biodegradable linear–hyperbranched barbell-like poly(ethylene glycol) (PEG)-supported poly(lactic-ran-glycolic acid) (PLGA) copolymers were synthesized with PEG, d,l-lactic acid aqueous solution, glycolic acid and gluconic acid (Glu) under bulk conditions. The branching density of the hyperbranched section was varied by controlling the molar ratio of Glu to hydroxyl-terminal groups of PEG ([Glu]/[OH] = 1, 3.5, 6.0, 8.5). Chemical structures of these copolymers were confirmed using NMR spectroscopy. The molecular weights were determined using 1H NMR group analysis and gel permeation chromatography, both results being consistent with one another. The results of hydrolytic degradation indicate that these copolymers can degrade completely in no more than three weeks. The thermal properties were evaluated using differential scanning calorimetry and thermogravimetric analysis. The results indicate that the glass transition temperatures and melt temperatures of these copolymers are not above 50 °C. The self-assembly behavior of the copolymers on hydrophilic surfaces was also investigated. The morphology of self-assembly films made of the copolymers was observed using atomic force microscopy, and the results indicate that these copolymers exhibit more inhomogeneous and rough structural orientated films on a silicon wafer substrate with increasing branching densities. Due to the favorable biodegradability and biocompatibility of the PLGA and PEG, the results suggest new possibilities for these novel structural amphiphilic linear–hyperbranched barbell-like copolymers as potential biomaterials. © 2013 Society of Chemical Industry

A series of biodegradable multifunctional hyperbranched-linear-hyperbranched copolymers (HLHCs) were prepared by poly(ethylene glycol), D,L-lactic acid, and 2,2-Bis(hydroxymethyl)propionic acid (BHP) under bulk condition. The degree of branching of the hyperbranched section was varied by controlling the molar ratio of BHP to hydroxyl-terminal groups of PEG ([BHP]/[OH] = 1, 3, 7, 15). Chemical structure of the copolymers was confirmed by both 1H-NMR and 13C-NMR spectroscopy. The molecular weights were determined by 1H-NMR end-group analysis and gel permeation chromatography, respectively. The resulting copolymers were subsequently characterized via atomic force microscopy, which was utilized in this research to investigate the Langmuir-Blodgett films morphology and the structure of barbell-like copolymers.

The novel biodegradable polylactic acid-β-cyclodextrin (PLA-β-CD) cross-linked copolymer microgels were prepared by the radical copolymerization of PLA macromonomer and polymerizable β-CD derivatives. The β-CD derivatives with various numbers of polymerizable vinyl groups were synthesized from 1-allyloxy-2,3-epoxy propane (also called allylglycidyl ether, AGE) and β-CD. The chemical structures of polymerizable monomers were determined by NMR. The thermal properties, size, morphology, in vitro degradation and swelling behavior of the microgels were investigated. The results indicated that the microgels were stable under thermal conditions up to 200 °C. The microgels were spherical in aqueous solution. The hydrophilicity of the microgels increased with increasing β-CD contents, while the swelling ratios and degradation rate decreased. The more vinyl groups on β-CD, the higher cross-linked density, which resulted in a decrease of the swelling ratios and the rate of degradation.

A novel functional polysiloxane (PSBP) bearing benzophenone derivatives as UV absorbing side groups was synthesized by hydrosilylation of polyhydromethylsiloxane (PHMS) with 2-hydroxy-4-(β-hydroxy-γ-allyloxy)propyloxy benzophenone (HHAPB). The chemical structure, film morphology, and the softening fabric property of the synthesized polysiloxane were characterized and investigated by spectrum analysis, atomic force microscope (AFM), and Kawabata evaluation system. The experiment results indicated that PSBP was not only an excellent polymeric UV-absorber, which showed intensive ultraviolet absorptions respectively, at wavelengths of 243.2, 288.2, and 325.4 nm, but could exhibit a nonhomogeneous, some rough structure film on silicon wafer substrate. In addition, the functional side group, benzophenone derivative as well as its mass ratio to PSBP has an influence on the performance of the synthesized polysiloxane. As the mass ratio decreased from 31.48 to 12.87%, the molar extinction coefficients emax (λmax = 288.2 nm) of the PSBP fluids lowered from 3.4564 × 105 to 1.5763 × 105, but while the softening fabric properties of PSBP on cotton fabrics increased. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 680–687, 2007