Polymer Moieties Research Articles

Poly[tris-(2-amino-butan-1-ol)copper(II) [hexa-kis-μ2-cyanido-κ12 C:N-tetra-copper(I)] bis-(2-amino-butan-1-olato)aqua-copper(II) monohydrate

The title structure, {[Cu(C4H11NO)3][Cu4(CN)6]·[Cu(C4H10NO)2(H2O)]·H2O} n , is made up of diperiodic honeycomb CuICN networks built from [Cu4(CN)6]2- units, together with two independent CuII complexes: six-coord-inate [Cu(CH3CH2CH(NH2)CH2OH)3]2+ cations, and five-coordinate [Cu(CH3CH2CH(NH2)CH2O)2·H2O] neutral species. The two CuII complexes are not covalently bonded to the CuICN networks. Strong O-H⋯O hydrogen bonds link the CuII complexes into pairs and the pairs are hydrogen bonded into chains along the crystallographic b axis via the hydrate water mol-ecule. In addition, O-H⋯(CN) and N-H⋯(CN) hydrogen bonds link the cations to the CuCN network. In the honeycomb polymeric moiety, all bridging cyanido ligands are disordered over two orientations, head-to-tail and tail-to-head, with occupancies for C and N atoms varying for each CN group.

Polymerizable alkyl 2-(tosylmethyl)acrylates: Highly efficient addition-fragmentation chain transfer agents for the development of low shrinkage dental composites

One of the major drawbacks for restorative dentistry is the polymerization shrinkage and the consequential shrinkage stress in methacrylate-based dental composites. An efficient way to reduce shrinkage stress is the incorporation of addition fragmentation chain transfer agents (AFCT agents). In this contribution, five novel polymerizable allyl sulfones were synthesized in four to five steps. A photo-DSC study was carried out in order to evaluate the influence of the addition of each AFCT agent on the polymerization rate of a dimethacrylate-based monomer mixture. The glass transition temperature (Tg) of the resulting networks was measured using DMTA. Dental composites based on these new chain transfer agents (CTAs) were prepared. A combination of camphorquinone, ethyl 4-(dimethylamino)benzoate and bis-(4-t-butylphenyl)-iodonium hexafluorophosphate was selected as photoinitiator system. Low shrinkage force values, suitable ambient light working time and excellent mechanical properties were obtained for all CTA based materials. Composites based on three of the synthesized CTAs even exhibited higher flexural modulus than the corresponding CTA-free material. Furthermore, a significant reduction of unreacted CTA leaching was found if a polymerizable moiety was introduced in the CTA structure. Hence, the incorporation of polymerizable allyl sulfones in dental composites is a promising strategy to obtain low shrinkage materials exhibiting improved biocompatibility.

Understanding local interactions in freestanding flexible poly(vinylidene fluoride)/poly(3,4‐ethyelenedioxythiophene):poly(styrelenesulfonate) films using impedance, Raman, and X‐ray absorption spectroscopy

AbstractThe local interaction within poly(vinylidene fluoride)/poly(3,4‐ethyelenedioxythiophene):poly(styrelenesulfonate) (PVDF/PEDOT:PSS) composite films has been explored in this study. Vibrational and impedance spectroscopy were used extensively to investigate the potential interactions within the moieties of PVDF and PEDOT:PSS in the composite. The increased concentration of PEDOT:PSS used as additives enhanced the dielectric constant of the composite films significantly. Both the AC conductivity and the estimated mobility also increased in the composite films with increasing additives. X‐ray absorption spectroscopy gave an insight into the local chain interactions within the polymer composite films. A shift in the C K‐edge toward higher energy confirmed the local interaction of the polymer moieties, suggesting a change in the polymer chain structure due to the possible association of moieties.

Preparation and Structural Analysis of Lipoteichoic Acid on Cell Membranes Derived from Lactic Acid Bacteria.

Gram-positive bacteria, including lactic acid bacteria (LAB), possess lipoteichoic acid (LTA) on the cell surface. LTA is an amphiphilic molecule typically composed of hydrophilic glycerolphosphate polymer and hydrophobic anchor glycolipid moieties. It is involved in physiological properties of the cell surface and also plays roles in interactions with the host. Appropriate preparation procedures, such as extraction and purification, are required to clarify the structure-activity relationship. Structural diversity of LTA has been reported at the bacterial species and strain levels, and structural differences might affect interactions with the host. This chapter introduces techniques for preparation and structural analysis of LTA derived from LAB. It consists of four sections, covering butanol extraction, hydrophobic interaction chromatography, immunoblotting, and structural analysis. Technical notes containing supplemental information about the individual steps are also provided.

Inducing an Amorphous Phase in Polymer Plastic Crystal Electrolyte for Effective Ion Transportation in Lithium Metal Batteries

AbstractPolymer plastic crystal electrolytes (PPCEs) have garnered significant attention for addressing the challenges associated with succinonitrile (SN), including its inadequate mechanical properties and side reactions with electrodes. However, a comprehensive investigation of the influence of the molecular structure of the polymer network on the states of SN within the network and its subsequent impact on ionic conductivities remains largely unexplored. To shed light on this critical aspect, the binding energy between SN and the polymer moiety is investigated as a determining factor in the conformation and crystallization behavior of SNs, through the dispersion‐corrected density functional theory (DFT‐D) simulations. These findings reveal that variations in miscibility resulting from the effects of binding energy significantly affected the formation of the amorphous phase in PPCEs. As a result, vinyl ethylene carbonate (VEC)‐based PPCE exhibits high ionic conductivity at room temperature (2.6 × 10−3 S cm−1 at 25 °C) and possesses a completely amorphous phase, which can be attributed to the optimized miscibility among its components. The feasibility of using a high‐performance solid‐state lithium‐metal battery (LMB) configuration is also examined by combining the PPCE with LiFePO4 (LFP) and LiNi0.8Co0.1Mn0.1O2 (NCM811) cathode materials.

Carboxymethyl chitosan dopamine conjugates: Synthesis and evaluation for intranasal anti Parkinson therapy

With respect to the Parkinson's disease (PD), herein, we aimed at synthetizing and characterizing two novel macromolecular conjugates where dopamine (DA) was linked to N,O-carboxymethyl chitosan or O-carboxymethyl chitosan, being both conjugates obtained from an organic solvent free synthetic procedure. They were characterized by FT-IR, 1H NMR spectroscopies, whereas thermal analysis (including Differential Scanning Calorimetry and Thermal Gravimetric Analysis) revealed good stability of the two conjugates after exposure at temperatures close to 300 °C. Release studies in simulated nasal fluid elucidated that a faster release occurred since O-carboxymethyl chitosan-DA conjugate maybe due to the less steric hindrance exerted by the polymeric moiety. The CMCS-DA conjugates prepared in aqueous medium may self-assembly to form polymeric micelles and/or may form polymeric nanoparticles. TEM and Photon correlation spectroscopy lent support for polymeric nanoparticle formation. Moreover, such CMCS-DA conjugates showed antioxidant activity, as demonstrated by DPPH radical scavenging assay. Finally, cytocompatibility studies with neuroblastoma SH-SY5Y cells showed no cytotoxicity of both conjugates, whereas their uptake increased from 2.5 to 24 h and demonstrated in 40–66 % of cells.

Flexible Fabrication and Hybridization of Bioactive Hydrogels with Robust Osteogenic Potency.

Osteogenic scaffolds reproducing the natural bone composition, structures, and properties have represented the possible frontier of artificially orthopedic implants with the great potential to revolutionize surgical strategies against the bone-related diseases. However, it is difficult to achieve an all-in-one formula with the simultaneous requirement of favorable biocompatibility, flexible adhesion, high mechanical strength, and osteogenic effects. Here in this work, an osteogenic hydrogel scaffold fabricated by inorganic-in-organic integration between amine-modified bioactive glass (ABG) nanoparticles and poly(ethylene glycol) succinimidyl glutarate-polyethyleneimine (TSG-PEI) network was introduced as an all-in-one tool to flexibly adhere onto the defective tissue and subsequently accelerate the bone formation. Since the N-hydroxysuccinimide (NHS)-ester of tetra-PEG-SG polymer could quickly react with the NH2-abundant polyethyleneimine (PEI) polymer and ABG moieties, the TSG-PEI@ABG hydrogel was rapidly formed with tailorable structures and properties. Relying on the dense integration between the TSG-PEI network and ABG moieties on a nano-scale level, this hydrogel expressed powerful adhesion to tissue as well as durable stability for the engineered scaffolds. Therefore, its self-endowed biocompatibility, high adhesive strength, compressive modulus, and osteogenic potency enabled the prominent capacities on modulation of bone marrow mesenchymal stem cell (BMSCs) proliferation and differentiation, which may propose a potential strategy on the simultaneous scaffold fixation and bone regeneration promotion for the tissue engineering fields.

Recent Advances in Various Inorganic Nanoparticle Embedded Chitosan-based Multifunctional Materials for Wound Healing

Abstract: Scarless wound management remains a clinical challenge worldwide because of its com-plicated and overlapping phases of inflammation, clearing, and regeneration. Among the currently available dressing materials, hydrogels have attracted emerging attention as potential wound dress-ing materials because of their specific properties, such as porosity, tissue-mimicking architecture, softness, and improved mechanical, biological as well as physicochemical properties. However, naturally driven hydrogels have shown several advantages over conventional hydrogels because of their biodegradability, biocompatibility, high mechanical strength, and functionality. Recently, na-noparticle (NPs) integrated polymeric hydrogels (metals, non-metals, metal oxides, and polymeric moieties) have been established as analogous to these naturally driven hydrogels because of the synergistic effects of the NPs and polymers in the three-dimensional composite material. Over the years, researchers have reported the synthesis and potential applications of diverse inorganic and organic nanocomposite gels with antioxidant or antibacterial properties where they have exploited the intelligent incorporation of biomolecules into the NP-polymeric network that are beneficial for wound healing. Among various natural polymers as hydrogel matrix, chitosan-mediated hydrogel dressings have received extensive interest resulting in improved mechanical, biological, and physi-cochemical properties due to the well-reported antibacterial, antitumor, antioxidant, and tissue re-generation efficacies of chitosan polymer. This review is intended to summarize the recent devel-opments of inorganic nanoparticle-incorporated chitosan-based hydrogels as wound dressing mate-rials where various synthetic methodologies of these nanocomposite gels are extensively discussed via incorporating nanoparticles, active biomolecules, and other substances into the intrinsic struc-ture of the gels. In addition, the future and prospects of chitosan-based nanocomposite hydrogels as a novel wound dressing as well as tissue engineering materials are also highlighted.

Armor‐like Inorganic‐rich Cathode Electrolyte Interphase Enabled by the Pentafluorophenylboronic Acid Additive for High‐voltage Li||NCM622 Batteries

AbstractLithium metal batteries (LMBs) comprising Li metal anode and high‐voltage nickel‐rich cathode could potentially realize high capacity and power density. However, suitable electrolytes to tolerate the oxidation on the cathode at high cut‐off voltage are urgently needed. Herein, we present an armor‐like inorganic‐rich cathode electrolyte interphase (CEI) strategy for exploring oxidation‐resistant electrolytes for sustaining 4.8 V Li||LiNi0.6Co0.2Mn0.2O2 (NCM622) batteries with pentafluorophenylboronic acid (PFPBA) as the additive. In such CEI, the armored lithium borate surrounded by CEI up‐layer represses the dissolution of inner CEI moieties and also improves the Li+ conductivity of CEI while abundant LiF is distributed over whole CEI to enhance the mechanical stability and Li+ conductivity compared with polymer moieties. With such robust Li+ conductive CEI, the Li||NCM622 battery delivered excellent stability at 4.6 V cut‐off voltage with 91.2 % capacity retention after 400 cycles. The excellent cycling performance was also obtained even at 4.8 V cut‐off voltage.

Armor-like Inorganic-rich Cathode Electrolyte Interphase Enabled by the Pentafluorophenylboronic Acid Additive for High-voltage Li||NCM622 Batteries.

Lithium metal batteries (LMBs) comprising Li metal anode and high-voltage nickel-rich cathode could potentially realize high capacity and power density. However, suitable electrolytes to tolerate the oxidation on the cathode at high cut-off voltage are urgently needed. Herein, we present an armor-like inorganic-rich cathode electrolyte interphase (CEI) strategy for exploring oxidation-resistant electrolytes for sustaining 4.8 V Li||LiNi0.6 Co0.2 Mn0.2 O2 (NCM622) batteries with pentafluorophenylboronic acid (PFPBA) as the additive. In such CEI, the armored lithium borate surrounded by CEI up-layer represses the dissolution of inner CEI moieties and also improves the Li+ conductivity of CEI while abundant LiF is distributed over whole CEI to enhance the mechanical stability and Li+ conductivity compared with polymer moieties. With such robust Li+ conductive CEI, the Li||NCM622 battery delivered excellent stability at 4.6 V cut-off voltage with 91.2 % capacity retention after 400 cycles. The excellent cycling performance was also obtained even at 4.8 V cut-off voltage.

Pluronic-123 Assisted Synthesis of Cobalt Vanadate Microparticles (µ-CoV MPs) for Durable Electrochemical Oxygen Evolution Reaction in Seawater and Connate Water

Exploring different catalytic material paradigms could drive the search for the best oxygen evolution reaction (OER) catalyst to achieve industrially-feasible hydrogen fuel from water. Cobalt-based materials are considered good choices in this regard. Herein, we synthesized Pluronic-123 (P-123)-stabilized, unique, rough, globular-shaped cobalt vanadate microparticles (µ-CoV MPs) using an ultrasonic-assisted solvothermal method. The as-synthesized µ-CoV MPs were subjected to high-temperature annealing to improve the crystallinity and the surface polymer moieties were pyrolyzed. Conventional SEM, XRD, FTIR, and BET analyses evaluated the morphological and structural features. The temperature-controlled crystalline phase led to extensive OER performance in SW electrolytes. The OER onset potential (VOER) was observed at 1.557 V@10 mA/cm2 in seawater (SW) for µ-CoV MPs annealed at 400 °C compared to the VOER of 1.632 V of non-annealed µ-CoV MPs. The current density showed a steep increase beyond 1.557 V, confirming the excellent electrokinetics OER behavior of the µ-CoV MPs-deposited electrode. The chronoamperometric (I–t) OER stability comparison in SW and connate water (CW) electrolytes indicated only a <20% initial current density decrease after 8 h in the case of the SW electrolyte. However, the CW electrolyte posed serious challenges to the electrode and activity was completely lost after <2 h. The electrolytic comparison indicated that SW is highly suitable for µ-CoV MPs electrodes.

Promising synthesized bis (arylmethylidene) acetone -polymeric PCL emulsified nanoparticles with enhanced antimicrobial/antioxidant efficacy: in-vitro and in-vivo evaluation

IntroductionRecently, bis(arylmethylidene)acetone drugs known as C5-curcumin, were acknowledged for their potent biological effects as a neoteric synthetic alternative to curcumin effectively used to treat many diseases. MethodsIn this study, new polymeric emulsified nanoparticles (PENS) carrying biodegradable polycaprolactone (PCL) polymer moieties within their framework were developed as promising carriers for a modern synthesized bis(arylmethylidene)acetone “(1E,4E)-1,5-di(thiophen-2-yl) penta-1,4dien-3-one” (TPO) with improved bioavailability. Such systems were evaluated by studying their; encapsulation efficiency, release behavior, physicochemical evaluations, TEM and SEM measurements and cytotoxicity, besides the in-vitro and in-vivo biological studies screening. ResultsThe results revealed high encapsulation efficiency ranging between 99.31± 2.15 and 99.55 ± 2.03 %, and a sustained release behavior for up to 24 h with nanosized particle size. TPO emulsified nanoparticles (TPO-ENPs) showed effective antimicrobial activity against Candida albicans and Aspergillus brasiliensis as well as antioxidant efficacy with a higher scavenging activity of 177.6μg TE/ mg against free radicals of 2,2-diphenyl-1-picrylhydrazyl hydrate (DPPH) relatively to the control drug. F1’ and F2’ TPO-ENPs were safe on Vero-cells and proved a significant reduction of hepatocellular alterations and serum ALT levels in control groups. ConclusionIn conclusion, these novel synthesized TPO-ENPs showed pronounced efficacy as antimicrobial/ antioxidant/ anti-inflammatory/ analgesic/ hepatoprotective therapeutic vehicles.

Unique Properties and Emerging Applications of Carbolong Metallaaromatics.

ConspectusAromatic compounds are important in synthetic chemistry, biomedicines, and materials science. As a special type of aromatic complex, transition-metal-based metallaaromatics contain at least one transition metal in an aromatic framework. The chemistry of metallaaromatics has seen much progress in computational studies and synthetic methods, but their properties and applications are still emerging. In recent years, we have disclosed a series of metal-centered conjugated polycyclic metallacycles in which a carbon chain is chelated to a metal center through at least three metal-carbon bonds. These are termed carbolong complexes and exhibit good stability to water, oxygen, light, and heat on account of their polydentate chelation and aromaticity, making them easy to handle. Carbolong complexes are not only special π-conjugated aromatics but also organometallics; therefore, they have the properties of both species. In this Account, we showcase the recent advances in their applications based on their different properties.First, carbolong complexes are a special kind of π-conjugated aromatic, with the ability to transmit electrons, allowing them to function as single-molecule conductors and candidates for electron transporting layer materials (ETLs) in solar cells. A series of carbolong complexes have been proved to be useful as achievable ETLs which enhance device performance in both organic solar cells and perovskite solar cells.Second, due to the involvement of d orbitals in the conjugation, carbolong complexes normally exhibit strong and broad absorption, even in some cases extending to the near-infrared region (NIR). The absorbed optical energy can be converted into light, heat, and ultrasound; consequently, carbolong compounds can be used as core moieties in smart materials. For example, 7C carbolong complexes were found to exhibit aggregation-enhanced near-infrared emission (AIEE). Some 12C carbolong complexes have been designed into the core moieties of NIR-responsive polymers, such as cylindrical NIR-responsive materials, self-healing materials, and shape memory materials. In contrast to the stereotypically toxic osmium compounds such as the highly toxic OsO4, some osmium carbolong complexes exhibit low cell cytotoxicity and good biocompatibility; consequently, they also have potential applications in the biomedical area. For example, benefiting from broad absorption in the NIR, 9C and 12C carbolong complexes have been used in photoacoustic imaging and photothermal therapy, respectively. In addition, photodynamic therapeutic applications which take advantage of a carbolong peroxo complex are discussed.Third, as special transition-metal complexes chelated by carbon-based ligands, a carbolong peroxo complex has displayed catalytic activity in the dehydrogenation of alcohols and a bimetallic carbolong complex has been used to catalyze difunctionalization reactions of unactivated alkenes.Overall, aromatic carbolong complexes have been applied to photovoltaics, smart materials, phototherapy, and catalytic reactions. Moving forward, we hope that this Account will shed light on future studies and theoretical research and encourage more discoveries of the properties of other metallaaromatics.

Self-assembled aggregates based on cationic amphiphilic peptides: structural insight.

Short and ultra-short peptides have recently emerged as suitable building blocks for the fabrication of self-assembled innovative materials. Peptide aggregation is strictly related to the amino acids composing the sequence and their capability to establish intermolecular interactions. Additional structural and functional properties can also be achieved by peptide derivatization (e.g. with polymeric moieties, alkyl chains or other organic molecules). For instance, peptide amphiphiles (PAs), containing one or more alkyl tails on the backbone, have a propensity to form highly ordered nanostructures like nanotapes, twisted helices, nanotubes and cylindrical nanostructures. Further lateral interactions among peptides can also promote hydrogelation. Here we report the synthesis and the aggregation behaviour of four PAs containing cationic tetra- or hexa-peptides (C19-VAGK, C19-K1, C19-K2 and C19-K3) derivatized with a nonadecanoic alkyl chain. In their acetylated (Ac-) or fluorenylated (Fmoc-) versions, these peptides previously demonstrated the ability to form biocompatible hydrogels potentially suitable as extracellular matrices for tissue engineering or diagnostic MRI applications. In the micromolar range, PAs self-assemble in aqueous solution into nanotapes, or small clusters, resulting in high biocompatibility on HaCat cells up to 72 hours of incubation. Moreover, C19-VAGK also forms a gel at a concentration of 5 wt%.

New Hg(II) coordination polymers based on a thioimidazole ligand with good performance to detoxify Hg(II) and reversibly capture iodine.

In the current paper, we have successfully synthesized three new mercury coordination polymers with fascinating structures and properties via a flexible sulfur donor ligand, namely, {[Hg(μ2-Cl)(μ2-Ls)]}n[BF4]n(1), {[Hg(μ2-Cl)(μ2-Ls)]}n[ClO4]n(2), and [Hg(SCN)2(μ2-Ls)]n(3) [Ls = 1,1-bis(3-methyl-4-imidazoline-2-thione)methane]. These complexes have been characterized by means of different techniques such as single crystal X-ray crystallography, FT-IR, elemental analysis (CHNS), UV-Vis, PXRD, BET, and TGA. Suitable single crystals of all complexes were obtained using the branch tube method with a very high yield and good stability due to the high affinity of mercury to bind to the thione groups. The cationic moieties of polymers 1 and 2 were isostructural, with a HgCl2S2 coordination core structure. The voids of the quasi-hexagonal packing of the columnar chains were occupied by unbonded tetrahedral BF4- ions in 1 and perchlorate anions in polymer 2. Polymer 3 has a less distorted tetrahedral geometry than 1 and 2, with a HgS4 core structure. By considering the thiophilicity of mercury, a thioamide-based Ls ligand was used to detoxify Hg(II) into insoluble polymers 1-3. The results of an MTT assay for (HepG2) liver cells confirmed the excellent cytoprotective effect of this ligand against mercury. Based on IC50 calculations, their toxicity was in order of polymer 1 > polymer 2 > polymer 3. These polymers were also considered as adsorbents for the reversible removal of iodine from solution and the kinetics of the process has been studied in detail. Interestingly, all of them showed an excellent stability and high capacity, in order of 763.53 mg g-1, 877.10 mg g-1, and 905.31 mg g-1 for polymers 1-3, respectively.

Transfer-based nuclear magnetic resonance uncovers unique mechanisms for protein-polymer and protein-nanoparticle binding behavior.

Nanoparticle-based drug delivery systems have shown increasing popularity as a means to improve patient outcomes by improving the effectiveness of active pharmaceutical ingredients (APIs). Similarly, nanoparticles have shown success in targeting alternative routes of API administration, such as applying mucoadhesion or mucopenetration to mucosal drug delivery to enhance uptake. While there are many promising examples of mucoadhesive nanomedicines in literature, there are also many examples of contradictory mucoadhesive binding behavior, most prominently in cases using the same nanoparticle materials. We have uncovered mechanistic insights in polymer-protein binding systems using nOe transfer-based NMR and sought to leverage them to explore nanoparticle-protein interactions. We tested several polymer-coated nanoparticles and micellar polymer nanoparticles and evaluated their binding with mucin proteins. We uncovered that the composition and interaction intimacy of polymer moieties that promote mucin binding change when the polymers are incorporated onto nanoparticle surfaces compared to polymer in solution. This change from solution state to nanoparticle coating can enable switching of behavior of these materials from inert to binding, as we observed in polyvinyl pyrrolidone. We also found the nanoparticle core was influential in determining the binding fate of polymer materials, whereas the nanoparticle size did not possess a clear correlation in the ranges we tested (60-270 nm). These experiments demonstrate that identical polymers may switch their binding behavior to mucin as a function of conformational changes that are induced by incorporating the polymers onto the surface of nanoparticles. These NMR-derived insights could be further leveraged to optimize nanoparticle formulations and guide polymer-mediated mucoadhesion.

Bis(Vinylenedithio)-Tetrathiafulvalene-Based Coordination Networks.

Novel coordination polymers embedding electroactive moieties present a high interest in the development of porous conducting materials. While tetrathiafulvalene (TTF) based metal-organic frameworks were reported to yield through-space conducting frameworks, the use of S-enriched scaffolds remains elusive in this field. Herein is reported the employment of bis(vinylenedithio)-tetrathiafulvalene (BVDT-TTF) functionalized with pyridine coordinating moieties in coordination polymers. Its combination with various transition metals yielded four isostructural networks, whose conductivity increased upon chemical oxidation with iodine. The oxidation was confirmed in a single-crystal to single-crystal X-ray diffraction experiment for the Cd(II) coordination polymer. Raman spectroscopy measurements and DFT calculations confirmed the oxidation state of the bulk materials, and band structure calculations assessed the ground state as an electronically localized antiferromagnetic state, while the conduction occurs in a 2D manner. These results are shedding light to comprehend how to improve through-space conductivity thanks to sulfur enriched ligands.

A Janus Au-Polymersome Heterostructure with Near-Field Enhancement Effect for Implant-Associated Infection Phototherapy.

Polymer-inorganic hybrid Janus nanoparticles (PI-JNPs) have attracted extensive attention due to their special structures and functions. However, achieving the synergistic enhancement of photochemical activity between polymer and inorganic moieties in PI-JNPs remains challenging. Herein, the construction of a novel Janus Au-porphyrin polymersome (J-AuPPS) heterostructure by a facile one-step photocatalytic synthesis is reported. The near-field enhancement (NFE) effect between porphyrin polymersome (PPS) and Au nanoparticles in J-AuPPS is achieved to enhance its near-infrared (NIR) light absorption and electric/thermal field intensity at their interface, which improves the energy transfer and energetic charge-carrier generation. Therefore, J-AuPPS shows a higher NIR-activated photothermal conversion efficiency (48.4%) and generates more singlet oxygen compared with non-Janus core-particle Au-PPS nanostructure (28.4%). As a result, J-AuPPS exhibits excellent dual-mode (photothermal/photodynamic) antibacterial and anti-biofilm performance, thereby significantly enhancingthe in vivo therapeutic effect in an implant-associated-infection rat model. This work is believed to motivate the rational design of advanced hybrid JNPs with desirable NFE effect and further extend their biological applications.

Synthesis and electrocatalysis of ordered carbonaceous frameworks from Ni porphyrin with four ethynyl groups

Ordered carbonaceous frameworks (OCFs) are carbon materials possessing three-dimensional ordered structures with regularly-aligned single-atomic metal species. OCFs are characterized by well-defined chemical structures like organic-based frameworks together with high thermal/chemical stability and electrical conductivity, making them an interesting platform for electrocatalytic applications. OCFs are synthesized by a simple thermal treatment of metalloporphyrin crystals with polymerizable moieties, but the reported precursors have been limited to only four types. Herein, we report two new types of Ni porphyrin precursors which can be converted into OCFs. The comprehensive structural analysis of resulting OCFs, including PXRD, TEM, HAADF-STEM, Ni K-edge XAFS and N2 adsorption measurement, demonstrated that Ni-N4 coordination units, namely single-atomic Ni sites, are regularly immobilized in the microporous carbon framework. There is a general tendency in which the higher the number of ethynyl moieties, the more the microporosity developed in the resulting OCFs. Furthermore, single-atomic Ni species catalyze electrochemical hydrogen evolution reaction even without any conductive additives.

Cyclopentenedione-based ascorbate-rejecting permselective layers prepared by electropolymerization

This work focuses on the preparation and optimization of organic functional layers based on 4-cyclopentene-1,3-dione. Hybrid molecules composed of 4-cyclopentene-1,3-dione anchored to a polymerizable moiety based either on pyrrole or methoxybenzene derivatives were synthesized and used for the preparation of thin films by electropolymerization. It is shown that the cyclopentenedione-containing films suppress the ascorbate (negatively charged) electrochemical response when deposited on glassy carbon electrodes, while the response connected to dopamine (positively charged) electrooxidation remains unaffected or is only slightly suppressed. The ascorbate-dopamine selectivity was studied in detail by voltammetry with stationary and rotating disk electrodes.