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Abstract: It would be ideal to have implants which can simultaneously inhibit bacterial adhesion and promote osteoblast functions. In this work, titanium surfaces were modified with poly(methacrylic acid) (P(MAA)) followed by immobilization of silk sericin. Firstly a trichlorosilane coupling agent, which is an atom transfer radical polymerization (ATRP) initiator, was immobilized on the oxidized titanium surface to facilitate the surface-initiated ATRP of methacrylic acid sodium salt (MAAS). The pendant carboxyl end groups of the grafted and partially protonated MAA chains were subsequently coupled with silk sericin via carbodiimide chemistry. The functionalized Ti surfaces were characterized by X-ray photoelectron spectroscopy, and assayed for osteoblast cell functions and bacterial adhesion. The covalently immobilized MAA brushes significantly reduce the adhesion of the two bacterial strains (Staphylococcus aureus and Staphylococcus epidermidis) tested. The silk sericin-immobilized surfaces, at the same time, promote osteoblast cells'' adhesion, proliferation, and alkaline phosphatase activity. Thus, the P(MAA) and silk sericin functionalized Ti surfaces have potential applications combating biomaterial-centered infection and promoting osseointegration. [Copyright &y& Elsevier]

Fabrication of versatile hydrogels in a facile and effective manner represents a pivotal challenge in the field of biomaterials. Herein, a novel strategy is presented for preparing on‐demand degradable hydrogels with multilevel responsiveness. By employing selenol‐dichlorotetrazine nucleophilic aromatic substitution (SNAr) to synthesize hydrogels under mild conditions in a buffer solution, the necessity of additives or posttreatments can be obviated. The nucleophilic and redox reactions between selenol and tetrazine culminate in the formation of three degradable chemical bonds—diselenide, aryl selenide, and dearomatized selenide—in a single, expeditious step. The resultant hydrogel manifests exceptional adaptability to intricate environments in conjunction with self‐healing and on‐demand degradation properties. Furthermore, the resulting material demonstrated light‐triggered antibacterial activity. Animal studies further underscore the potential of integrating metformin into Se‐Tz hydrogels under green light irradiation, as it effectively stimulates angiogenesis and collagen deposition, thereby fostering efficient wound healing. In comparison to previously documented hydrogels, Se‐Tz hydrogels exhibit controlled degradation and drug release, outstanding antibacterial activity, mechanical robustness, and bioactivity, all without the need for costly and intricate preparation procedures. These findings underscore Se‐Tz hydrogels as a safe and effective therapeutic option for diabetic wound dressings. [ABSTRACT FROM AUTHOR]

Abstract: A novel monomer containing triazole and naphthalene ring, 2-(1-naphthalen-1-ylmethyl-1H-[1,2,3]triazol-4-yl)-ethyl methacrylate (NTEMA), was designed and synthesized via “click” chemistry method. The RAFT polymerization of NTEMA was successfully carried out using 2-cyanoprop-2-yl dithiobenzoate (CPDB) as a RAFT agent, 2,2′-azobisisobutyronitrile (AIBN) as an initiator in tetrahydrofuran (THF) solution. The results showed that the polymerizations exhibited “living”/controlled characteristics. The obtained poly(2-(1-naphthalen-1-ylmethyl-1H-[1,2,3]triazol-4-yl)-ethyl methacrylate) homopolymers, PNTEMAs, were further coordinated with samarium ion to prepare rare earth containing polymers (PNTEMA–Sm(III) complexes) which were characterized by FT-IR, DSC and ICP-AES. The characterization data confirmed that triazole in side chain of the polymer could coordinate with Sm(III). The fluorescence property of the polymers and polymer Sm(III) complexes were investigated in solution and in film. [Copyright &y& Elsevier]

Ring-opening copolymerization (ROCOP) is an effective means to prepare functionalized polyester. In this work, a type of selenide-containing polyesters with controllable structure, molecular weight, and molecular weight distribution was successfully prepared by ROCOP of γ-selenobutyrolactone and epoxy compounds. The influence of the catalyst, solvent, and reaction temperature on the reaction efficiency was examined. Then, kinetic study was investigated under an optimized condition. The structure of the copolymers was carefully characterized by nuclear magnetic resonance (NMR), 1H NMR, 13C NMR, and 77Se NMR, Matrix-assisted laser-desorption-ionization time-of-flight mass spectrometry (MALDI-TOF-MS), and size exclusion chromatography (SEC). The resulting polymers showed a linear structure with a sequence regulated backbone repeating unit of ester-selenide. On this basis, some typical epoxides were investigated to verify the scope of the polymerization system. Due to the "living"/controlled characteristics of this ROCOP, multiblock, amphiphilic, and stereotactic copolymers could be prepared with a pre-designed structure. As expected, the selenide-containing amphiphilic copolymer could self-assemble to micelles and showed an oxidative response. [ABSTRACT FROM AUTHOR]

The easily encodable and decodable digital polymer using dithiosuccinimide as sequence building block and sequencing indicator was proposed. • The easily encodable and decodable digital polymer was realized. • Dithiosuccinimide was used as the sequence building block for facile encoding information. • Dithiosuccinimide was used as the sequencing indicator was proposed for the ease of decoding information. Digital polymers with precise arrangements of units acting as the 0- or 1-bit, have shown bright promise for the data storage media. The easiness of encoding and decoding these polymers is essential when putting them into practical applications. Herein, the concept of utilizing sequence building block and sequencing indicator to generate easily encodable and decodable digital polymers is proposed. With the thiol-maleimide Michael coupling for digital chain growth, the dithiosuccinimide (DTS) motifs generated from the succinimide thioether linkages are used as the sequence building block. The DTS can be equipped with different groups, thus greatly enabling the modular encoding process. Importantly, the tandem mass spectrometry (MS/MS) results unveil the relatively abundant DTS-induced MS signal, which facilitates the decoding process with DTS acting as the sequencing indicator. The synergetic MS/MS induced cleavages of the two C S bonds on DTS are responsible for the relatively abundant MS signal. Finally, the work exemplifies the quantitatively decoding of a digital polymer with DTS as the sequence building block and sequencing indicator. This study demonstrates the concept of sequence building block and sequencing indicator, which advances the digital polymers for practical applications. [ABSTRACT FROM AUTHOR]

Cyclic polymers, having no chain ends, are in contrast to their linear counterparts with respect to topology and related properties. While the behavior of cyclic polymers in solution is well investigated, there is little information on the effects of cyclic chain topology on surfaces grafted with these polymers. In particular, the effects of topology on the interactions of such surfaces with biological systems are unknown. In this work, we prepared gold surfaces modified with either cyclic or linear polystyrene (CPS, LPS) using a grafting-to strategy, and used these surfaces to investigate the effects of chain topology on their biointerfacial interactions. It was shown that compared to LPS with similar molecular weight, the smaller hydrodynamic radius of CPS leads to brushes of higher chain density, and that the higher chain density facilitates the adsorption of larger proteins but suppresses the adsorption of smaller ones. However, no significant differences in bacterial attachment or mammalian cell proliferation between CPS and LPS brushes were found, indicating that topological effects are absent for the larger entities. [ABSTRACT FROM AUTHOR]

Aqueous two-phase systems (ATPSs) based on ionic liquids (ILs) are efficient and green extraction systems. In this study, ATPSs consisted of three hydrophilic imidazolium-based ionic liquids ([C 4 mim]Br, [C 6 mim]Br, and [C 8 mim]Br) with phosphate, which were employed for Pd(II) extraction in acidic solutions. The obtained results showed that IL-ATPSs exhibited excellent Pd(II) extraction performance in acidic media, and Pd(II) was concentrated into ionic liquid rich upper phase. Palladium(II) extraction efficiencies of the three imidazolium-based ILs in acidic media were >98%, and the order of extraction efficiencies was: [C 4 mim]Br > [C 6 mim]Br > [C 8 mim]Br. Palladium(II) concentrated in IL-rich phase was recovered via direct reduction with hydrazine hydrate. Fourier transform infrared spectrometer (FT-IR) and mass spectrometry characterization indicated that Pd(II) migration into IL-rich phase followed an ion-exchange mechanism. Furthermore, transmission electron microscopy showed that "oil-in-water" micelles were formed during Pd(II) extraction. • The order of extraction efficiencies was: [C 4 mim]Br > [C 6 mim]Br > [C 8 mim]Br. • IL-based ATPSs can efficiently extract Pd(II) in acidic medium. • The Pd(II) extraction mechanism of IL-based ATPSs was studied. [ABSTRACT FROM AUTHOR]

[Display omitted] • The use of La/Ca-BDC-1 can reduce the cost of phosphorus removal by about 40%. • La/Ca-BDC-1 can efficiently remove phosphorus from natural water. • The phosphorus removal mechanism of La/Ca-BDC-1 was studied. In this study, low-cost and water-stable La/Ca bimetallic organic framework (La/Ca-BDC) are synthesized and used for the efficient removal of phosphorus in water. The study of adsorption isotherms shows that the high concentration of Ca in La/Ca-BDC-1 (prepared with Ca molar fraction in the precursor as high as 50%) has little interference to the phosphorous adsorption capacity (66.0 mg g−1) compared with that of the La-BDC (71.0 mg g−1), or only 7.0% drop, but it translates to significantly reduced cost of phosphorus removal by about 40.0%. The kinetic study of phosphorus removal process using the synthesized La/Ca-BDC-n conforms to the pseudo-second-order kinetic model. In addition, the synthesized La/Ca-BDC-1 is suitable for phosphorus removal in wide pH water (3.0–9.0). More importantly, the manufactured La/Ca-BDC-1 can efficiently remove the phosphorus in the actual water. In addition, even if there are interfering ions (Ca2+, Mg2+, CO 3 2–, HCO 3 –, SO 4 2- and Cl-) with concentration of five times of the phosphorus, the phosphorus removal efficiency of La/Ca-BDC-1is hardly affected. Interestingly, the removal efficiency of La/Ca-BDC-1 for phosphorus is still higher than 70% after five cycles. From the FT-IR and XPS analysis, it is shown that ligand exchange and complexation are the main phosphorus removal mechanisms of La/Ca-BDC-1. [ABSTRACT FROM AUTHOR]

[Display omitted] • First microflow cationic polymerization under ambient conditions. • No further purification of all reagents were required. • Well-defined poly(vinyl ether)s can be achieved within 2 min. Living cationic polymerization is a well-established method for preparing polymers with controlled molecular weights and complex architectures, but rigorous polymerization conditions limit its widespread application. Here, we report a facile strategy for simplifying the strict conditions required for traditional living cationic polymerizations of various vinyl ethers including ethyl vinyl ether (EVE), propyl vinyl ether (PVE), butyl vinyl ether (BVE) and isobutyl vinyl ether (IBVE) by utilizing continuous microflow reactors and a weak Lewis acid, zinc chloride (ZnCl 2). Well-defined polymers with controlled molecular weights and narrow molecular weight distributions (<1.20) can be obtained under ambient conditions without monomer purification, temperature control or strictly anhydrous conditions. The living nature of the polymerization was verified by kinetic experiments and successful in situ chain extension. [ABSTRACT FROM AUTHOR]

Abstract: Reversible addition-fragmentation chain transfer (RAFT) polymerization of VAc in the presence of ECTVA, which capable of both reversible chain transferable through a xanthate moiety and propagation via a vinyl group, led to highly branched copolymers by a method analogous to self-condensing vinyl polymerization (SCVP). The ECTVA acted as a vinyl acetate AB ∗ inimer. It was copolymerized with vinyl acetate (VAc) in ratios selected to tune the distribution and length of branches of resulting hyperbranched poly(vinyl acetate). The degree of branching increased with chain ECTVA concentration, as confirmed by NMR spectroscopy. The polymer structure was characterized via MALDI–TOF. Retention of the xanthate compound during the polymerization was evidenced by successful chain extension of a branched (PVAc) macroCTA by RAFT polymerization. The branched PVAc led to better dissolution as compared to linear PVAc, an effect attributed primarily to an increased contribution of end groups. [Copyright &y& Elsevier]

Recently, the design of novel supramolecular chiral materials has received a great deal of attention due to rapid developments in the fields of supramolecular chemistry and molecular self-assembly. Supramolecular chirality has been widely introduced to polymers containing photoresponsive azobenzene groups. On the one hand, supramolecular chiral structures of azobenzene-containing polymers (Azo-polymers) can be produced by nonsymmetric arrangement of Azo units through noncovalent interactions. On the other hand, the reversibility of the photoisomerization also allows for the control of the supramolecular organization of the Azo moieties within polymer structures. The construction of supramolecular chirality in Azo-polymeric self-assembled system is highly important for further developments in this field from both academic and practical points of view. The postpolymerization self-assembly strategy is one of the traditional strategies for mainly constructing supramolecular chirality in Azo-polymers. The in situ supramolecular self-assembly mediated by polymerization-induced self-assembly (PISA) is a facile one-pot approach for the construction of well-defined supramolecular chirality during polymerization process. In this review, we focus on a discussion of supramolecular chirality of Azo-polymer systems constructed by traditional postpolymerization self-assembly and PISA-mediated in situ supramolecular self-assembly. Furthermore, we will also summarize the basic concepts, seminal studies, recent trends, and perspectives in the constructions and applications of supramolecular chirality based on Azo-polymers with the hope to advance the development of supramolecular chirality in chemistry. [ABSTRACT FROM AUTHOR]

Combing active ester chemistry and click chemistry, a cyclic double-grafted polymer was successfully demonstrated via a "grafting onto" method. Using active ester chemistry as post-functionalized modification approach, cyclic backbone (c-P2) was synthesized by reacting propargyl amine with cyclic precursor (poly(pentafluorophenyl 4-vinylbenzoate), c-PPF4VB6.5k). Hydroxyl-containing polymer double-chain (l-PS-PhOH) was prepared by reacting azide-functionalized polystyrene (l-PSN3) with 3,5-bis(propynyloxy)phenyl methanol, and further modified by azide group to generate azide-containing polymer double-chain (l-PS-PhN3). The cyclic backbone (c-P2) was then coupled with azide-containing polymer double-chain (l-PS-PhN3) via CuAAC reaction to construct a novel cyclic double-grafted polymer (c-P2-g-Ph-PS). This research realized diversity and complexity of side chains on cyclic-grafted polymers, and this cyclic double-grafted polymer (c-P2-g-Ph-PS) still exhibited narrow molecular weight distribution (Mw/Mn < 1.10). [ABSTRACT FROM AUTHOR]

This work developed novel selenium-containing polyimides with a high intrinsic refractive index. Four polyimides with different selenium contents and repeat unit structures were designed and synthesized via amine-dianhydride polycondensation of one of two diamines, i.e., 4,4′-oxydianiline or bis(4-aminophenyl)selanide, with one of two dianhydrides, i.e., bis(4-(3,4-dicarboxylbenzoyloxy)phenyl) ester dianhydride or 1,1′-bis(4-(3,4-dicarboxylbenzoyloxy)phenyl) selenide dianhydride. Various techniques, e.g., nuclear magnetic resonance, Fourier transformed infrared spectroscopy, and wide-angle X-ray diffraction, were used to characterize the polymers’ structures. Differential scanning calorimetry, thermogravimetric analysis, ultraviolet-visible spectroscopy, and spectroscopic ellipsometry were used to characterize the properties of the polymers. The selenium contents showed a positive effect on the refractive index of the final polymer. In addition, the refractive index can reach up to 1.968 at 633 nm, which was the highest intrinsic refractive index of a polyimide ever reported. Because of the high intrinsic refractive index, the reflective ratio of visible light on the surface of a silicon wafer was significantly reduced, indicating the potentially utility of the polymer in an anti-reflection coating. [ABSTRACT FROM AUTHOR]