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Bacterial infections, especially those from drug‐resistant strains, pose a significant threat to healing diabetic skin injuries, with current treatments being intricated and often unsatisfactory. Inspired by octopuses, a biomimetic material using α‐cyclodextrin (α‐CD) and polyethylene glycol (PEG) assembled with graphene oxide end‐capped polyrotaxanes (GO‐PR) is developed, where α‐CD mimics the flexible tentacles of an octopus. Further, α‐CD is cationically modified with polyethyleneimine (PEI) to resemble octopus suction cups, creating GO‐PRP, which effectively captures and adheres to bacteria. Importantly, to emulate an octopus's ink defense, GO‐PRP is used as a carrier for nitric oxide (NO), resulting in GO‐PRP/NONOate. Utilizing the photothermal conversion of GO, near‐infrared light exposure triggers rapid heating and NO release, providing efficient antibacterial activity and biofilm dispersion, significantly reducing inflammation in diabetic skin injuries in type I rats. During wound healing, sustained NO release promotes vascular endothelial growth factor production and blood vessel regeneration, enhancing collagen formation and shortening the healing time for diabetic skin infections. Thus, octopus‐inspired GO‐PRP/NONOate emerges as a novel biomaterial for treating drug‐resistant bacterial infections in diabetic wounds in the biomedical field. [ABSTRACT FROM AUTHOR]

Polyrotaxane (PR) has garnered increasing attention due to its unique structure and exceptional performance. In this study, a polypseudorotaxane (PPR) initiator was prepared through the self-assembly of bromine-capped Pluronic F68 and β-cyclodextrins (β-CD) in water. Polyrotaxane-containing triblock copolymers (PR copolymers) were successfully synthesized by atom transfer radical polymerization (ATRP) of butyl methacrylate (BMA) using the PPR initiator in the presence of Cu(I)Br/PMDETA. The structure of the PR copolymers was thoroughly characterized using infrared spectroscopy (IR), proton nuclear magnetic resonance (1H NMR), and gel permeation chromatography (GPC). The mobility of β-CD in the PR copolymers was demonstrated through dielectric measurements. Mechanical tests, including tensile strength assessments, thermal mechanical analysis, and dynamic mechanical analysis, confirmed the excellent mechanical properties and good processability of the PR copolymer, attributed to the PBMA blocks. Furthermore, the mechanical properties were found to be modulated by the motility of the threaded β-CDs. Consequently, the superior mechanical properties and the high mobility of the threaded β-CDs suggest promising potential for the as-prepared PR polymer in various advanced applications. [ABSTRACT FROM AUTHOR]

An aqueous solution of chlorinated polyethylene glycol (Cl-PEG-Cl) and α-cyclodextrin (α-CD) was used to form inclusion complexes, which several α-CDs are threaded into the linear PEG chain and produced a so-called polypseudorotaxane (PPRx). By attaching 4-ethylaniline as the blocking agent to the chlorinated PEG chain ends, the complex will be stabilized, resulting in the formation of so-called polyrotaxane (PRx) (also known as molecular necklace). Finally, crosslinked αCD-based PRx with a tubular structure was formed via the condensation reactions between α-cyclodextrins and epichlorohydrin. Using concentrated NaOH solution, polymer chains were then removed from complexes, resulting in the so-called molecular tube (MT). This novel method led to the improvement in polyrotaxane conversion with less production steps and reduced materials overall costs. Resulting products in each section were characterized by 1H and 13C nuclear magnetic resonance spectroscopies (1H-NMR and 13C-NMR), from which complex inclusion ratio and length of the nanotubes were estimated. XRD was also used to confirm tubular structure of the inclusion complexes. [ABSTRACT FROM AUTHOR]

Although our knowledge and understanding of adsorptions in natural and artificial systems has increased dramatically during the past century, adsorption associated with nonporous polymers remains something of a mystery, hampering applications. Here we demonstrate a model system for adaptisorption of nonporous polymers, wherein dative B−N bonds and host‐guest binding units act as the kinetic and thermodynamic components, respectively. The coupling of these two components enables nonporous polymer crystals to adsorb molecules from solution and undergo recrystallization as thermodynamically favored crystals. Adaptisorption of nonporous polymer crystals not only extends the types of adsorption in which the sorbate molecules are integrated in a precise and orderly manner in the sorbent systems, but also provides a facile and accurate approach to the construction of polymeric materials with precise architectures and integrated functions. [ABSTRACT FROM AUTHOR]

Although our knowledge and understanding of adsorptions in natural and artificial systems has increased dramatically during the past century, adsorption associated with nonporous polymers remains something of a mystery, hampering applications. Here we demonstrate a model system for adaptisorption of nonporous polymers, wherein dative B−N bonds and host‐guest binding units act as the kinetic and thermodynamic components, respectively. The coupling of these two components enables nonporous polymer crystals to adsorb molecules from solution and undergo recrystallization as thermodynamically favored crystals. Adaptisorption of nonporous polymer crystals not only extends the types of adsorption in which the sorbate molecules are integrated in a precise and orderly manner in the sorbent systems, but also provides a facile and accurate approach to the construction of polymeric materials with precise architectures and integrated functions. [ABSTRACT FROM AUTHOR]

The pulley structure has been widely employed to improve mechanical properties. Polyrotaxane‐based waterborne polyurethane (WPU) typically exhibits good tensile strength and Young's modulus. However, achieving outstanding self‐healability of polyrotaxane‐based WPU under mild conditions generally proves insufficient solely relying on host‐guest interactions. Herein, a strategy that constructs a triple synergy of host‐guest interaction, hydrogen bonds, and metal coordination bonds by sequentially introducing tannic acid (TA) and Fe3+ is proposed to prepare polyrotaxane‐based WPU with excellent mechanical performance and high self‐healable capability. Besides the reversible non‐covalent bonding contributing to intrinsic self‐healing, the unique sliding motion of WPU's molecule chain acts as a driving force, promoting efficient contact among reversible bonds. Notably, benefiting from the sliding motion of β‐cyclodextrin (β‐CD) along a chain, the dynamic reconstruction of hydrogen bonds and metal coordination bonds, the resulting supramolecular WPU exhibited a tensile strength of 46.05 MPa and a toughness of 130.30 MPa, with satisfactory self‐healing performance (tensile strength healing efficiency of more than 95%). This work enriches the self‐healing mechanism and expands the concepts for the design of resilient self‐healing environmentally friendly supramolecular WPU. [ABSTRACT FROM AUTHOR]

We previously reported that acid-degradable methylated β-cyclodextrins (Me-β-CDs)-threaded polyrotaxanes (Me-PRXs) can induce autophagic cell death through endoplasmic reticulum (ER) stress-related autophagy, even in apoptosis-resistant cells. Hence, Me-PRXs show great potential as anticancer therapeutics. In this study, peptide-supermolecule conjugates were designed to achieve the targeted delivery of Me-PRX to malignant tumors. Arg-Gly-Asp peptides are well-known binding motifs of integrin αvβ3, which is overexpressed on angiogenic sites and many malignant tumors. The tumor-targeted cyclic Arg-Gly-Asp (cRGD) peptide was orthogonally post-modified to Me-PRX via click chemistry. Surface plasmon resonance (SPR) results indicated that cRGD-Me-PRX strongly binds to integrin αvβ3, whereas non-targeted cyclic Arg-Ala-Glu (cRGE) peptide conjugated to Me-PRX (cRGE-Me-PRX) failed to interact with integrins αvβ3. In vitro, cRGD-Me-PRX demonstrated enhanced cellular internalization and antitumor activity in 4T1 cells than that of unmodified Me-PRX and non-targeted cRGE-Me-PRX, due to its ability to recognize integrin αvβ3. Furthermore, cRGD-Me-PRX accumulated effectively in tumors, leading to antitumor effects, and exhibited excellent biocompatibility and safety in vivo. Therefore, cRGD conjugation to enhance selectivity for integrin αvβ3-positive cancer cells is a promising design strategy for Me-PRXs in antitumor therapy. [ABSTRACT FROM AUTHOR]

Polymer‐based composites containing functional organic fillers with polyvinylidene fluoride (PVDF) as a matrix were prepared using a simple and short melt‐compounding method, and their mechanical properties were evaluated. Polyrotaxane and nanocellulose were used as functional organic fillers. A PVDF/organic filler composite with improved mechanical hardness was prepared, even when using a fluoropolymer that tends to separate phases from other components. The optimum conditions for improving in Young's modulus were estimated from the composites prepared by varying the organic filler content. As a result, the Young's modulus increased to 1548 MPa, maximum stress approached 50 MPa, and strain elongation was 20% at contents of polyrotaxane:nanocellulose = 0.6 wt%:0.3 wt%. Furthermore, the miscibility of both components was evaluated based on the change in the crystallization temperature of the composite, the PVDF matrix, and each organic filler. The partial miscibility and dispersion of the organic fillers in the fluoropolymer matrix are suggested to be responsible for improving the mechanical properties. Highlights: Unique composites containing nanocellulose and polyrotaxane were prepared.Organic fillers were introduced into a phase‐separable fluoropolymer matrix.Mechanical properties were improved by introduction of organic fillers.Nanocellulose seems to adsorb to the polymer chain ends of fluoropolymer.Polyrotaxane showed partial miscibility with fluoropolymer matrix. [ABSTRACT FROM AUTHOR]

Phase change materials (PCMs) have received much attention regarding the thermal regulation of electronic devices. However, the main limitations of using organic PCMs are the low thermal conductivity and leakage during the phase change process. This work aims to improve these limitations to increase the thermal conductivity of the leakage‐proof PCM formed by a polyrotaxane that serves as a support material to encapsulate PEG. For this purpose, different contents of graphene nanoplatelets (GNP) are blended. To facilitate its postindustrial production and to meet ecological standards, the synthesis of this PCM is simple and only using water as a solvent. The PCMs can be thermally processed conveniently by a hot press. Furthermore, the PCMs achieve high enthalpy values (132.9–142.9 J g−1) due to the action of GNPs as thermally conductive fillers. The PCMs exhibited an increase of 60–257% in thermal conductivity values with higher GNP content, and show great shape stability and no leakage during phase change. These improvements solve the main problems of organic PCMs, thus making PLR‐PEG‐GNP‐based materials a good candidate for use as thermal energy storage materials in industrial applications as thermoregulators of solid‐state disks or realizing the "shaving peaks and filling valleys" effect for thermoelectric generators. [ABSTRACT FROM AUTHOR]

Herein, polymer-based composites containing polyrotaxane and nanocellulose as organic fillers and organo-modified carbon nanotubes as inorganic nanofillers in a polypropylene matrix were prepared. The two types of functional organic fillers were combined with polypropylene using a simple melt-compounding method and showed improved mechanical properties in the matrix polymer. A jet-black composite material was obtained by combining organo-modified carbon nanotubes and long-chain phosphonic acid as a modifier to the polypropylene matrix. In this case, the long-chain phosphonic acid modifier exhibited effects typical of filler dispersants. Polymer composites containing two types of functional organic fillers and organo-modified carbon nanotubes were prepared uniaxially. In the drawn composites, the carbon nanotubes showed a uniaxial orientation, dramatically improving the mechanical characteristics of the prepared materials. [ABSTRACT FROM AUTHOR]

Molecular gels, which are soft and flexible materials, are candidates for healthcare, cosmetic base, and electronic applications as new materials. In this study, a new polymeric organogelator bearing a polyrotaxane (PR) structure was developed and could induce the gelation of N′,N″-dimethylformamide (DMF), a known solvent for dissolving polymeric materials and salts. Furthermore, the resulting DMF molecular gels exhibited thixotropic properties, observed by the inversion method using vials, which are essential for gel spreading. The scanning electron microscopy of the xerogels suggested that the gel-forming ability and thixotropic property of gels were imparted by the network of the laminated aggregates of thin layer material similar to those of other gels made of clay materials. This thin layer material would be formed by the aggregation of polymeric organogelators. The dynamic viscoelasticity measurements of the obtained gels revealed the stability and pseudo-thixotropic behaviors of the obtained gels, as well as a specific concentration effect on the mechanical behavior of the gels attributed to the introduction of the PR structure. Additionally, the preparation of the polymer organogelator/polymer composites was investigated to improve the mechanical properties via the filler effect induced by the agglomerates of organogelator. Moreover, the tensile tests confirmed that the introduction of the gelator enhanced the mechanical properties of the composites. [ABSTRACT FROM AUTHOR]

New composite materials were prepared via cross-linking of polyethylene glycol/2-hydroxypropyl-β-cyclodextrins polyrotaxane (PEG/HPβCD) and polyisoprene/HPβCD semi-polyrotaxane (PI/HPβCD SR) with 1,6-hexamethylene diizocyanate (HMDI). Advanced instrumental methods (such WAXS (wide angle X-ray scattering), AFM (atomic force microscopy), SEM (scanning electron microscopy), and thermal and dynamic vapor sorption) were employed for the structural, morphological and thermal characterization of the resulting composite materials. The roughness parameters calculated using AFM indicate a smoother surface for the composite material with 10 wt% of PI/HPβCD SR, denoting that a homogeneous film was obtained. SEM analysis reveals porous morphologies for both composite materials and the pore sizes increase with the increasing concentration of PI/HPβCD SR in the matrix. Dynamic vapor sorption/desorption measurements and type IV isotherms confirmed the hydrophilic and porous materials, which are in agreement with SEM analysis. The composite with a higher PI/HPβCD SR concentration in the matrix showed increased thermal stability than that of the pure cross-linked material. This material was further tested as a sorbent for methylene blue (MB) dye removal from an aqueous solution. The adsorption capacity of the composite film was found to be 2.58 mg g−1 at 25 °C. [ABSTRACT FROM AUTHOR]

Preparing strong and flexible atelocollagen-based materials for biomedical applications is still a challenging task. To address this challenge, this study describes the synthesis and characterization of water-soluble polyrotaxanes (PRs) with different coverage ratios and molecular weights of axle polymers, and their potential applications for PR-reinforced atelocollagen threads (PRATs). A novel method was established for the syntheses of PRs with relatively low coverage ratio at the sub-gram scale, in which the aldehyde groups were employed as crosslinking sites for preparing the PRATs via reductive amination. The aldehyde groups were successfully quantified by 1H nuclear magnetic resonance spectroscopy using 1,1-dimethylhydrazine as an aldehyde marker. Fourier-transform infrared and thermogravimetric analysis measurements supported the characterization of the PRs. Interestingly, tensile testing demonstrated that coverage ratio affected the mechanical properties of the PRATs more strongly than molecular weight. The insights obtained in this study would facilitate the development of soft materials based on atelocollagens and PRs. [ABSTRACT FROM AUTHOR]

Activation of autophagy represents a potential therapeutic strategy for the treatment of diseases that are caused by the accumulation of defective proteins and the formation of abnormal organelles. Methylated β-cyclodextrins-threaded polyrotaxane (Me-PRX), a supramolecular structured polymer, induces autophagy by interacting with the endoplasmic reticulum. We previously reported on the successful activation of mitochondria-targeted autophagy by delivering Me-RRX to mitochondria using a MITO-Porter, a mitochondria-targeted nanocarrier. The same level of autophagy induction was achieved at one-twentieth the dosage for the MITO-Porter (Me-PRX) compared to the naked Me-PRX. We report herein on the quantitative evaluation of the intracellular organelle localization of both naked Me-PRX and the MITO-Porter (Me-PRX). Mitochondria, endoplasmic reticulum and lysosomes were selected as target organelles because they would be involved in autophagy induction. In addition, organelle injury and cell viability assays were performed. The results showed that the naked Me-PRX and the MITO-Porter (Me-PRX) were localized in different intracellular organelles, and organelle injury was different, depending on the route of administration, indicating that different organelles contribute to autophagy induction. These findings indicate that the organelle to which the autophagy-inducing molecules are delivered plays an important role in the level of induction of autophagy. [ABSTRACT FROM AUTHOR]

The mechanical properties and miscibility of polymer‐based composites containing cellulose nanofiber (CNF) and polyrotaxane (p‐rtx) as organic fillers were studied in detail. CNF and p‐rtx were introduced as powders into a polypropylene (PP) matrix, and composites were prepared using a simple melt‐compounding method. The best mechanical properties were achieved when CNF and p‐rtx were loaded at a concentration of 0.6 wt%. The Young's modulus of the composite increased by 760 MPa compared with that of the PP matrix. In addition, the presence of mica in the composite promoted the epitaxial growth of PP along the (1 3 0) plane. The various shifts in the melting/crystallization temperatures of the composites prepared at different CNF:p‐rtx ratios confirmed the partial miscibility between the fillers and the matrix. The enhancement in the mechanical properties of the composite is believed to be due to the miscibility of the surfaces of aggregates of the organic fillers with PP and the uniform dispersion of the organic fillers in the matrix. [ABSTRACT FROM AUTHOR]

Polymeric systems that provide cationic charges or biocide‐release therapeutics are used to treat the bacteria‐infected wound. However, most antibacterial polymers based on topologies with restricted molecular dynamics still do not satisfy the clinical requirements due to their limited antibacterial efficacy at safe concentrations in vivo. Here a NO‐releasing topological supramolecular nanocarrier with rotatable and slidable molecular entities is reported to provide conformational freedom to promote the interactions between the carrier and the pathogenic microbes, hence greatly improving the antibacterial performance. With improved contacting‐killing and efficient delivery of NO biocide from the molecularly dynamic cationic ligand design, the NO‐loaded topological nanocarrier achieves excellent antibacterial and anti‐biofilm effects via destroying the bacterial membrane and DNA. MRSA‐infected rat model is also brought out to demonstrate its wound‐healing effect with neglectable toxicity in vivo. Introducing flexible molecular motions into therapeutic polymeric systems is a general design to enhance the healing of a range of diseases. [ABSTRACT FROM AUTHOR]

Polyrotaxane (PR) is a supramolecular polymer in which an axial polymer extends through multiple cyclic molecules. Specifically, PR comprises polyethylene glycol, α‐cyclodextrin and adamantane as the axial polymer, cyclic molecule and terminal blocking group, respectively. PR is a useful stress relaxation material because the cyclic polymers can freely slide and rotate in cyclic motions on the axial polymer. In this study, 4,4′‐diphenylmethane bismaleimide (BMI)/2,2′‐diallylbisphenol A (DABPA) resin was blended with PR as a toughness modifier; the effect of PR on the cured properties of BMI/DABPA resin is reported and the properties are related to the phase structure of BMI/DABPA/PR alloy. The BMI/DABPA/PR alloy formed a microphase‐separated structure with PR particles dispersed in the BMI/DABPA resin matrix. Increasing PR concentration greatly improved the toughness, impact resistance and adhesiveness of the resin. The glass transition temperature also increased because the numerous hydroxyl groups of α‐cyclodextrins in PR formed intermolecular hydrogen bonds in the BMI/DABPA resin, forming a dense network structure. In contrast, owing to the small concentration ratio of PR to BMI/DABPA resin, the dielectric constant, dielectric loss tangent and water absorption were only slightly higher than those of the unmodified resin. © 2022 Society of Industrial Chemistry. [ABSTRACT FROM AUTHOR]

A solid slide‐ring supramolecular elastomer is constructed by free‐radical polymerization of 2‐(2‐methoxyethoxy)ethyl methacrylate, acrylate‐modified perylene diimides (PDI), and the polyrotaxane (PR) cross‐linker. Benefiting from reciprocating shuttle function of slide‐ring PR formed by acrylate‐modified α‐cyclodextrin threading on polyethylene glycol, the resultant supramolecular elastomer not only presents excellent tensile property, toughness, and fatigue resistance up to 100 cycles, but also gives reversible mechano‐induced fluorescence changes from red to orange luminescence due to a reversible conversion of PDI dimer to monomer upon mechanical stretching. After the dye molecule Nile blue is added as a fluorescent acceptor, the supramolecular elastomer exhibits highly reversible mechano‐induced regulation of energy transfer and can perform five cycles without optical fatigue. This bifunctional mechanochromic slide‐ring supramolecular elastomer, which not only possesses mechanically reversible motion of the slide‐ring cross‐linkers but also has the mechanochromic response of fluorophore, endows the intrinsic superiority of slide‐ring into fatigue resistant mechanoresponsive strain sensing materials. [ABSTRACT FROM AUTHOR]

Doxorubicin (DOX)-conjugated acid-degradable polyrotaxanes (PRXs) were designed as supramolecular drug carriers capable of releasing drugs in acidic cellular environments. Acid-degradable PRXs composed of α-cyclodextrin (α-CD) as a cyclic molecule, poly(ethylene glycol) (PEG) as a polymer axis, and N-triphenylmethyl (N-Trt) groups as an acid-labile stopper molecules were synthesized and DOX was conjugated with the threaded α-CDs in the PRXs. Because the acid-induced cleavage of N-Trt groups in PRXs leads to PRX dissociation, the DOX-modified α-CDs were released under acidic conditions (pH 5.0). The cytotoxicity of DOX-conjugated PRXs in colon-26 cells revealed significant cell death for DOX-conjugated PRXs after 48 h of treatment. Confocal laser scanning microscopy (CLSM) analysis revealed that the fluorescence signals derived from DOX-conjugated PRXs were observed in cellular nuclei after 48 h, suggesting that the DOX-modified α-CDs were released and accumulated in cellular nuclei. These results confirmed that acid-degradable PRXs can be utilized as drug carriers capable of releasing drug-modified α-CDs in acidic lysosomes and eliciting cytotoxicity. Overall, acid-degradable PRXs represent a promising supramolecular framework for the delivery and intracellular release of drug-modified α-CDs, and PRX–drug conjugates are expected to contribute to the development of pH-responsive drug carriers for cancer therapy. [ABSTRACT FROM AUTHOR]

Cyclodextrins (CDs) are one of the most extensively studied cyclic-oligosaccharides due to their low toxicity, good biodegradability and biocompatibility, facile chemical modification, and unique inclusion capacity. However, problems such as poor pharmacokinetics, plasma membrane disruption, hemolytic effects and a lack of target specificity still exist for their applications as drug carriers. Recently, polymers have been introduced into CDs to combine the advantages of both biomaterials for the superior delivery of anticancer agents in cancer treatment. In this review, we summarize four types of CD-based polymeric carriers for the delivery of chemotherapeutics or gene agents for cancer therapy. These CD-based polymers were classified based on their structural properties. Most of the CD-based polymers were amphiphilic with the introduction of hydrophobic/hydrophilic segments and were able to form nanoassemblies. Anticancer drugs could be included in the cavity of CDs, encapsulated in the nanoparticles or conjugated on the CD-based polymers. In addition, the unique structures of CDs enable the functionalization of targeting agents and stimuli-responsive materials to realize the targeting and precise release of anticancer agents. In summary, CD-based polymers are attractive carriers for anticancer agents. [ABSTRACT FROM AUTHOR]

Silicon is expected to become the ideal anode material for the next generation of high energy density lithium battery because of its high theoretical capacity (4200 mAh g−1). However, for silicon electrodes, the initial coulombic efficiency (ICE) is low and the volume of the electrode changes by over 300% after lithiation. The capacity of the silicon electrode decreases rapidly during cycling, hindering the practical application. In this work, a slidable and highly ionic conductive flexible polymer binder with a specific single‐ion structure (abbreviated as SSIP) is presented in which polyrotaxane acts as a dynamic crosslinker. The ionic conducting network is expected to reduce the overall resistance, improve ICE and stabilize the electrode interface. Furthermore, the introduction of slidable polyrotaxane increases the reversible dynamics of the binder and improves the long‐term cycling stability and rate performance. The silicon anode based on SSIP provides a discharge capacity of ≈1650 mAh g−1 after 400 cycles at 0.5C with a high ICE of upto 92.0%. Additionally, the electrode still exhibits a high ICE of 87.5% with an ultra‐high Si loading of 3.84 mg cm−2 and maintains a satisfying areal capacity of 5.9 mAh cm−2 after 50 cycles, exhibiting the potential application of SSIP in silicon‐based anodes. [ABSTRACT FROM AUTHOR]

Despite the high-energy densities, the safety problem of thermal runaway in lithium-ion batteries (LIBs) severely hinders their further application. Therefore, as an essential part of LIBs, the separator should ideally have good thermal stability at high temperatures. Here, a novel polyrotaxane (PR)-based gel polymer electrolyte (GPE) with good thermal stability is made by a simple solution casting method. The thermal shrinkage of the PR is less than 20% even heated at 200 °C; in contrast, the commercial Celgard 2400 separator undergoes dramatic deformation above 140 °C. The gel polymer electrolyte presents excellent compatibility in the cells of LiFePO4 and LiNi0.5Co0.2Mn0.3O2 cathode. The cell composed of Li/GPE/LiFePO4 presents good discharge performance and excellent stored performance. The cell composed of Li/GPE/LiNi0.5Mn0.3Co0.2O2 presents excellent capacity retention of 85.9% in 300 cycles while discharging at the 0.5 C rate. This GPE is promising to be applied to Li metal batteries with high safety and good cycle life. [ABSTRACT FROM AUTHOR]

The development of chemo/photothermal nanotherapeutic systems with excellent photothermal performance, stable drug loading, tumor targeting and strong membrane penetration still remains a challenge. To address this problem, herein a rod-like nanocomposite system (AuNR@FA-PR/PEG) forming from folic acid (FA) terminated carboxylated cyclodextrin (CD) pseudopolyrotaxane (FA-PR) and polyethylene glycol (PEG) modifying gold nanorods (AuNR) was reported. Cisplatin (CDDP) was loaded in AuNR@FA-PR/PEG via coordination bonds to prepare a rod-like pH-responsive nanosystem (AuNR@FA-PR/PEG/CDDP) with chemotherapy/photothermal therapy. The rod-like morphology of AuNR@FA-PR/PEG was characterized by transmission electron microscope. In vitro drug release experiments showed the pH-responsive of AuNR@FA-PR/PEG/CDDP. In vivo real-time imaging assays proved AuNR@FA-PR/PEG/CDDP could rapidly enrich in the tumor area and stay for a long time because of folate targeting and their rod-like morphology. In vivo photothermal imaging assays showed AuNR@FA-PR/PEG/CDDP excellent photothermal performance, the average temperature of tumor region could reach 63.5 °C after 10 min irradiation. In vitro and in vivo experiments also demonstrated that the combined therapy of chemotherapy and photothermal therapy had an outstandingly synergistic effect and improved the therapeutic efficacy comparing with chemotherapy and photothermal therapy alone. Therefore, the prepared rod-like AuNR@FA-PR/PEG/CDDP will provide a new strategy for the effective treatment of cancer. [ABSTRACT FROM AUTHOR]

Recently, the potential of β-cyclodextrin-thread acid-degradable polyrotaxane (AdPRX) has been emphasized as a therapeutic agent for cholesterol-related metabolic disorders. In this study, we investigated whether carboxymethyl carbamate-modified AdPRX (CMCAdPRX) can be used for adsorption to calcium phosphate to treat bone diseases. We first synthesized CMC-AdPRX and used it to coat the calcium phosphate plate. RAW264.7 cells were then differentiated into osteoclasts via a receptor activator of nuclear factor-κB ligand, and the number of osteoclasts and the area of absorption lacunae were determined. The number of tartrate-resistant acid phosphatase-positive multinucleated cells was reduced on the CMC-AdPRX-coated plate. The area of the absorption lacunae was smaller with CMC-AdPRX than with AdPRX, which was not carboxy-modified. Our results suggest that CMC-AdPRX can adsorb to calcium phosphate and act on differentiated osteoclasts to suppress their functional expression. [ABSTRACT FROM AUTHOR]

Poly(ethylene glycol) diamine 1,1'-disubstituted ferrocene was utilized as a size-com-plementary site to synthesize lower coverage pseudopolyrotaxanes (pPRs) from self-assemblies with β- and γ-cyclodextrins (CDs). After end-capping β-CD pPRs using N-(triphenylmethyl)glycine (Trt-Gly-OH), an exact β-CD [3]polyrotaxane (PR) was created. However, an unexpected γ-CD [2]PR and a predictive chain folded stranded γ-CD pPR were identified from end-capped γ-CD pPRs. After end-capping a β-CD pPR self-assembled from β-CDs with amine terminated PEG containing ferrocene as a site-complementary site using Trt-Gly-OH, an exact β-CD [3]PR is invariably created. However, an unexpected γ-CD [2]PR and a predictive chain folded stranded γ-CD pPR are identified from end-capping γ-CD pPRs with Trt-Gly-OH. [ABSTRACT FROM AUTHOR]

To improve the therapeutic potential of ß-cyclodextrin (ß-CD)-threaded acid-degradable polyrotaxanes (ß-CD PRXs) in cholesterol-related metabolic disorders, we investigated the effect of carboxylation of ß-CD PRXs on intracellular uptake. In this study, we established a synthetic method for the modification of carboxylalkyl carbamates on ß-CD PRXs without degradation and synthesized three series of carboxyalkyl carbamate group-modified ß-CD PRXs with different alkyl spacer lengths. The modification of carboxymethyl carbamate (CMC), carboxyethyl carbamate (CEC), and carboxypropyl carbamate (CPC) on the ß-CD PRXs slightly reduced the interaction of the PRXs with the lipid layer model compared with the modification of 2-(2-hydroxyethoxy)ethyl carbamate (HEE-PRX), which was used in our previous studies. However, all the carboxylated ß-CD PRXs showed a significantly stronger interaction with a protein model compared with HEE-PRX. The carboxylated ß-CD PRXs showed significantly high intracellular uptake, through macrophage scavenger receptor A (MSR-A)-mediated endocytosis, in MSR-A-positive RAW 264.7 cells compared with HEE-PRX. Interestingly, the carboxylated ß-CD PRXs also showed significantly higher intracellular uptake even in MSR-A-negative cells compared with HEE-PRX. Carboxylated ß-CD PRXs are considered to strongly interact with other membrane proteins, resulting in high intracellular uptake. The length of the alkyl spacer affected the intracellular uptake levels of carboxylated PRXs, however, this relationship was varied for different cell types. Furthermore, none of the carboxylated ß-CD PRXs exhibited cytotoxicity in the RAW 264.7 and NIH/3T3 cells. Altogether, carboxylation of ß-CD PRXs is a promising chemical modification approach for their therapeutic application because carboxylated ß-CD PRXs exhibit high cellular internalization efficiency in MSR-A-negative cells and negligible toxicity. [ABSTRACT FROM AUTHOR]

The mobility of molecular shuttles inside a mechanically interlocked polymer (MIP) can improve the ionic conductivity and electron transport capacity of a solid polymer electrolyte (SPE) and maintain a mechanically tough structure. The polyrotaxane‐based MIP electrolyte with a necklace‐like molecular structure exhibits high ionic conductivity (σ = 5.93 × 10−3 S cm−1 at 25 °C and 1.44 × 10−2 S cm−1 at 60 °C), a high Li+ ion transference number (t+ = 0.71), and high electrochemical oxidation stability (≈4.7 V vs Li+/Li). When SPEs are used in Li‐based batteries, a high Coulombic efficiency (≥98.5%), an excellent rate capability, and fast charging (≥2C) can be achieved using a "built‐in molecular shuttle" design. [ABSTRACT FROM AUTHOR]

Poly(ether ether ketone) (PEEK) is a high-performance thermoplastic used for several industrial applications due to its excellent mechanical properties. However, the use of PEEK is limited to dental materials because of its poor implant-bone integration. In the present study, methylated polyrotaxanes (MePRXs) with 4-vinylbenzyl groups, which are supermolecules composed of methylated α-cyclodextrins and poly(ethylene glycol) chains end-capped with 4-vinylbenzyl groups, were covalently tethered onto PEEK surfaces using photo-induced polymerization to improve their osteoblast compatibility. The surface-tethering of MePRXs onto PEEK surfaces was confirmed by analyzing their attenuated total reflectance Fourier transform infrared spectra and contact angles. When mouse preosteoblasts were cultured on the MePRX-PEEK and bare PEEK surfaces, the MePRX-PEEK surfaces showed significantly better proliferation and osteoblast differentiation than the bare PEEK surfaces. These results suggest that surface modification of PEEKs using MePRXs improves their osteoblast compatibility. [ABSTRACT FROM AUTHOR]

Currently, preparation of polymerizable polyrotaxane cross‐linkers (PCs) or pseudo‐polyrotaxane cross‐linkers (PPCs), including water‐soluble PCs or PPCs requires at least three‐step or more complicated chemical reactions. Herein, a simple and effective method is proposed to prepare two kinds of water‐soluble pseudo‐polyrotaxane cross‐linkers based on cyclodextrin. This means it is more convenient to apply the pulley effect to a wider range of hydrogels. The structures of cross‐linkers are characterized by nuclear magnetic resonance spectroscopy, X‐ray diffraction, and atomic force microscopy. Further, two kinds of pseudo‐polyrotaxane cross‐linkers and conventional cross‐linker are, respectively, copolymerized with acrylamide to prepare hydrogels to compare the properties of hydrogels. The swelling ratios and deformation ability of hydrogel prepared by pseudo‐polyrotaxane cross‐linker are better than that of hydrogel prepared by conventional cross‐linker. [ABSTRACT FROM AUTHOR]

As an effective alternative to suture in wound closure, tissue adhesives often need to have excellent biocompatibility and suitable bioadhesion. To achieve long‐term adhesion on moist tissue, polyrotaxane (PR) crosslinked self‐healing hydrogels have been prepared by the introduction of dynamic borate bonds between PR bearing phenylboronic acid moieties (PR‐PBA) and dopamine grafted poly(vinyl alcohol) (PVA‐DOP). Synthesis of these precursor polymers PR‐PBA and PVA‐DOP is quite simple and the hydrogels combine dynamic borate bonds with the sliding motion of the phenylboronic acid moieties on PR. The sliding nature of the crosslinking points along the axle in the PR is thought to enhance the mechanical properties and adhesion ability of the resultant hydrogels. Meanwhile, catechol groups on dopamine units have been protected by borate bonds under alkaline conditions to avoid oxidation, and they then are released to react with various functional groups on tissue surface to ensure the switchable tissue adhesion. The self‐healing test and adhesion of hydrogels on pigskin demonstrate the ability to restore the original performance after repeated strain cycles and maintain strong tissue adhesion. The components of these hydrogels have satisfying biocompatibility. These results indicate that these self‐healing hydrogels have great potentials in tissue adhesion. [ABSTRACT FROM AUTHOR]

The temperature‐dependent phase transition behavior of acetylated polyrotaxanes (PRXs) consisting of acylated α‐cyclodextrins threaded onto a poly(ethylene glycol) chain in an aqueous solution is investigated. Acetyl (Ac), propionyl (Pr), and butyryl (Bu) group‐modified PRXs with different degrees of substitution are synthesized to elucidate the effect of the alkyl chain length of the acyl groups on temperature responsivity. Ac‐PRXs, Pr‐PRXs, and Bu‐PRXs are dissolved in water and exhibit temperature‐dependent transmittance changes accompanied by coacervate formation. However, the temperature responsivity of acylated PRXs is seen in limited degree of substitution range (≈10%). The maximum degree of substitution to show temperature responsivity of acylated PRXs decreases with increasing alkyl chain length of the acyl groups. Transmittance measurements of acylated PRXs in the presence of urea reveal that the alkyl chain length of the acyl groups determines the predominant force involved in the temperature‐induced phase transition. During the temperature‐induced phase transition of Pr‐PRXs and Bu‐PRXs, hydrophobic interactions are predominant; however, hydrogen bond formation may occur in Ac‐PRXs. These fundamental findings related to acylated PRXs will facilitate the application of PRXs as thermoresponsive supramolecular materials. [ABSTRACT FROM AUTHOR]

Elastomers such as gels and rubbers play various roles in our lives. Elastomers, which guarantee the safety of airplanes and automobiles and the stability of buildings, are materials that have made the lives of people in the twentieth century extremely convenient. The existence of macromolecules, that is, giant molecules, has been clarified; the development of synthetic macromolecules has progressed; and understanding of elastomers has progressed. By introducing new ideas, it has become possible to obtain tough and hard elastomers, which was difficult under conventional ideas. In this paper, we will explain the development from the classical theory of elastomers to current efforts. [ABSTRACT FROM AUTHOR]

The fascinating pulley effect from moveable α‐cyclodextrin (α‐CD) based polyrotaxane favors toughening of hydrogels, but the strategy is rarely applied in bulk polymers because of the severe aggregation trend of α‐CDs. Herein, the authors propose a simple approach to moderately modify the α‐CDs of polyrotaxane by introducing large steric side groups and reactive CC so as to minimize the unwanted hydrogen bonds‐induced aggregation of α‐CDs and hydrophilicity of polyrotaxane. Accordingly, the proof‐of‐concept material, poly(methyl acrylate) crosslinked by the modified polyrotaxane, turns out to be rather homogeneous with optical transparency. The polyrotaxane crosslinks are movable under external force as disclosed by in situ small‐angle X‐ray scattering and other techniques, which is correlated to the relative amount of α‐CDs. A few polyrotaxane crosslinkers prove to be sufficient to simultaneously improve strength and toughness of poly(methyl acrylate) owing to the stress equalization. The present work provides an expandable toolbox for enhancing polymers. [ABSTRACT FROM AUTHOR]

Previously, we have reported a single-step preparation method for a topological gel by copolymerizing isoprene and vinyl-modified β-cyclodextrin (V-β-CyD). In the prepared gel, the vinyl part of V-β-CyD consists a part of the copolymer chain, and the β-CyD part includes another copolymer chain, thus V-β-CyD works as a cross-linker. We call the procedure rotaxa-polymeric-gelation (RPG) because polymerization, rotaxane formation, and gelation proceed simultaneously. In this study, we applied acrylamide (AAm) instead of isoprene for RPG, and successfully obtained highly swellable hydrogel. By contrast, a combination of V-β-CyD and N-isopropylacrylamide (NIPAAm) was not suitable for RPG because NIPAAm and cavity of β-CyD were mismatched in size. In addition, we prepared three-component gels. Among of them, gels composed of NIPAAm, isoprene, and V-β-CyD showed thermo-responsiveness by reflecting the character of polyNIPAAm. These results provide an insight for usage of vinyl monomers for RPG strategy. [ABSTRACT FROM AUTHOR]

Stimuli‐responsive materials have received considerable attention for their application in biomedical fields. Herein, the temperature‐dependent phase transition behavior of acetylated polyrotaxanes (Ac‐PRXs) consisting of acetylated cyclodextrins threaded onto a linear axle polymer in aqueous solution is investigated. The aqueous solutions of Ac‐PRXs exhibit temperature‐dependent transmittance changes when the degree of acetylation is 30–40%. Upon increasing the temperature, Ac‐PRXs are dehydrated and acetyl groups are subsequently associated through hydrophobic interactions. Interestingly, the Ac‐PRXs form coacervate droplets with a diameter of ≈2–3 µm above their cloud points. These temperature‐responsivities of Ac‐PRXs are observed for other PRXs with different axle polymer molecular weights and compositions. Consequently, the acetylation of PRXs is an attractive chemical modification for yielding temperature‐responsivities, and Ac‐PRXs can be applied as temperature‐responsive supramolecular materials. [ABSTRACT FROM AUTHOR]

Thermo- and pH-responsive polyrotaxane (PR)-based triblock copolymers were synthesized by atom transfer radical polymerization (ATRP) of N-isopropylacrylamide initiated with polypsudorotaxanes which were presynthesized from bromine end-capped poly(ethylene glycol)/poly(propylene glycol) with cyclodextrins in the presence of CuBr/HMDETA under near physiological conditions. The triblock copolymers were characterized by 1H NMR, FT-IR, GPC (gel permeation chromatography) analyses. Thermo- and pH-responsive behavior evaluated by UV–Vis spectroscopies, DLS (dynamic light scattering), and TEM (transmission electron microscopy) images showed that its lower critical solution temperature (LCST) was slightly increased with increasing pH values due to hydroxyl groups of cyclodextrin depending on pH values. [ABSTRACT FROM AUTHOR]

One novel metal halide clustered supramolecular polymer, {(BLP) [Ag8Br12]0.5}n(BLP = 1, 3-bis(3,5-lutidine)propane) has been synthesized via the self-assembly reaction in solution. 1 was characterized by X-ray crystal structure, PXRD, TG, elemental analysis, and UV-Vis. This compound exhibits two-dimensional polyrotaxane structure. Great efforts were devoted to investigate its applications in wastewater purification on the basis of methylene blue (MB) degradation. [ABSTRACT FROM AUTHOR]

Slide‐ring hydrogels using polyrotaxanes have been developed as highly tough soft materials. However, they have never been used as biomaterials because of the lack of biocompatibility. Meanwhile, self‐healing hydrogels are expected to improve fatigue resistance and extend the period of use. However, owing to the lack of high mechanical strength, they are limited in their use as biomaterials. Here we first developed a biocompatible self‐healing/slide‐ring hydrogel using glycol chitosan and a water‐soluble polyrotaxane. We obtained excellent mechanical toughness and biocompatibility to promote the proliferation of human umbilical vein endothelial cells (HUVECs) encapsulated in the hydrogel. Owing to the rapid self‐healing property, the cell‐encapsulating gels adjusted arbitrarily, maintaining good cell proliferation function. Therefore, slide‐ring hydrogels enable the use of biomaterials for soft‐tissue engineering. [ABSTRACT FROM AUTHOR]

Hepatocytes in vitro may be useful for treating various types of liver diseases, but these cells immediately lose their functions. Here, we designed sulfonated‐polyrotaxane (PRX) surfaces with immobilized heparin binding‐epidermal growth factor‐like growth factors (HB‐EGFs) for improving hepatic functions. Sulfonated‐PRX triblock copolymers, composed of sulfopropyl ether‐modified α‐cyclodextrins (α‐CDs) threaded onto a poly(ethylene glycol) (PEG) chain as a PRX segment and poly(benzyl methacrylate) at both terminals of the PEG as anchoring segments, were coated onto polystyrene surfaces by a drop cast method. The sulfonated‐PRX surfaces with a small number of threading α‐CDs induced cytoplasmic localization of yes‐associated proteins in HepG2 cells. Moreover, immobilization of HB‐EGFs onto the sulfonated‐PRX surfaces with a small number of threading α‐CDs promoted hepatic functions, including albumin secretion and gene expression. These results suggest that the combination of modulating the mobility of PRXs and immobilizing growth factors is effective for improving hepatic functions. © 2019 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 107A: 1080–1085, 2019. [ABSTRACT FROM AUTHOR]

A mechanical tough polylactic acid (PLA) that substantially retains its stiffness and transparency was created through reaction with a polyrotaxane derivative. A graft polyrotaxane (GPR), composed of a linear Polyethylene glycol backbone threaded with cyclodextrins bearing grafted poly(ε-caprolactone), was bonded to the hydroxyl end-groups of PLA with hexamethylene diisocyanate (HDI), which then solidified to form a PLA-bonded GPR that was distributed throughout the PLA matrix. The addition of 5 wt% GPR resulted in a seven-fold increase in Izod impact strength and a three-fold increase in fracture elongation, with only an 11% loss of stiffness; the transparency was comparable to neat PLA. Electron microscopy revealed that HDI facilitated the dispersal of GPR in the PLA matrix and avoided the sea-island phase-separated structure observed in the PLA/GPR blend devoid of HDI, and that the homogenized structure led to ductile deformation. A GPR content of only 5 wt% efficiently increased PLA-matrix-chain flexibility. [ABSTRACT FROM AUTHOR]

New antitumor active polyrotaxanes, presynthesized from β-cyclodextrin and polypropylene glycol, were first end capped with antitumor active drug, 5-fluorouracil, and further conjugated with 5-fluorouracil and various bioactive vitamin derivatives such as succinyl vitamin B2 (PRTVB2) and ascorbic acid 6-palmitate (PRTASP). FT-IR, 1H, and 13C-NMR spectroscopies and elemental analysis were used to characterize the synthesized polyrotaxane and degree of 5-fluorouracil/vitamins substitution to β-cyclodextrin. The in vitro cytotoxicities of polyrotaxane conjugates were evaluated with mouse mammary carcinoma (FM3A), mouse leukemia (P388), human histiocytic lymphoma (U937) as cancer cell lines, and mouse liver cells (AC2F) as a normal cell line. The cytotoxicities of the polyrotaxane–ascorbic acid conjugates against AC2F normal cell line decreased more than 18,000% as compared with those of 5-fluorouracil. The in vivo antitumor activities of synthesized 5-fluorouracil-1-acetic acid-polyrotaxane (5-FUA-PRT) against mice bearing sarcoma 180 tumor cell line were greater than of 5-fluorouracil at concentration of 800 mg/kg. [ABSTRACT FROM AUTHOR]

Abstract: In this study, 4,4′‐diphenylmethane bismaleimide (BMI)/2,2′‐diallylbisphenol A (DABPA) resin was modified with polyrotaxane (PR) as a stress relaxation material. Based on a dynamic mechanical analysis and various properties of the cured resin, the influence of the motion of PR on the cured properties of BMI/DABPA/PR alloy is discussed. The cyclic molecule α‐cyclodextrin (α‐CD) that is threaded onto the PR axis contains a methacryl group in its side chain that reacts with the allyl group of BMI/DABPA resin. The methacryl group of PR reacted with the allyl group of BMI/DABPA matrix resin to form a transparent and dense network structure, so that the glass transition temperature was increased with increasing PR concentration. In addition, the toughness, impact resistance and adhesiveness of BMI/DABPA resin were improved by modification with PR. These results indicate that the poly(ethylene glycol) chain, which is the axial polymer of the PR, moves in the space formed by the cavities of the threaded α‐CD and the surrounding BMI/DABPA resin matrix in the glassy state, thereby relaxing the internal stress applied to BMI/DABPA/PR resin. The range of applications of BMI/DABPA resin modified with PR may expand into fields requiring high heat resistance in addition to excellent toughness and adhesiveness. © 2018 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

Abstract: Supramolecular building blocks, such as cucurbit[n]uril (CB[n])‐based host–guest complexes, have been extensively studied at the nano‐ and microscale as adhesion promoters. Herein, we exploit a new class of CB[n]‐threaded highly branched polyrotaxanes (HBP‐CB[n]) as aqueous adhesives to macroscopically bond two wet surfaces, including biological tissue, through the formation of CB[8] heteroternary complexes. The dynamic nature of these complexes gives rise to adhesion with remarkable toughness, displaying recovery and reversible adhesion upon mechanical failure at the interface. Incorporation of functional guests, such as azobenzene moieties, allows for stimuli‐activated on‐demand adhesion/de‐adhesion. Macroscopic interfacial adhesion through dynamic host–guest molecular recognition represents an innovative strategy for designing the next generation of functional interfaces, biomedical devices, tissue adhesives, and wound dressings. [ABSTRACT FROM AUTHOR]

Amphiphilic nonionic ligands, synthesized with a fixed hydrophobic moiety formed by a thiolated alkyl chain and an aromatic ring, and with a hydrophilic tail composed of a variable number of oxyethylene units, were used to functionalize spherical gold nanoparticles (AuNPs) in water. Steady-state and time-resolved fluorescence measurements of the AuNPs in the presence of α-cyclodextrin (α-CD) revealed the formation of supramolecular complexes between the ligand and macrocycle at the surface of the nanocrystals. The addition of α-CD induced the formation of inclusion complexes with a high apparent binding constant that decreased with the increasing oxyethylene chain length. The formation of polyrotaxanes at the surface of AuNPs, in which many α-CDs are trapped as hosts on the long and linear ligands, was demonstrated by the formation of large and homogeneous arrays of self-assembled AuNPs with hexagonal close packing, where the interparticle distance increased with the length of the oxyethylene chain. The estimated number of α-CDs per polyrotaxane suggests a high rigidization of the ligand upon complexation, allowing for nearly perfect control of the interparticle distance in the arrays. This degree of supramolecular control was extended to arrays formed by AuNPs stabilized with polyethylene glycol and even to binary arrays. Electromagnetic simulations showed that the enhancement and distribution of the electric field can be finely controlled in these plasmonic arrays. [ABSTRACT FROM AUTHOR]

As a drug carrier, polyrotaxane (PR) has been used for targeted delivery and sustained release of drugs, whereas silver sulfadiazine (SD-Ag) is an emerging antibiotic agent. PR was synthesized by the use of α-cyclodextrin (CD) and poly(ethylene glycol) (PEG), and a specific antibacterial material (PR-(SD-Ag)) was then prepared by loading SD-Ag onto PR with different mass ratios. The loading capacity and the encapsulation efficiency were 90% at a mass ratio of 1:1 of PR and SD-Ag. SD-Ag was released stably and slowly within 6 d in vitro, and its cumulative release reached more than 85%. The mechanism of PR loading SD-Ag might be that SD-Ag attached to the edge of α-CD through hydrogen bonding. PR-(SD-Ag) showed a higher light stability than SD-Ag and held excellent antibacterial properties against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus). [ABSTRACT FROM AUTHOR]

A boronic acid-appended γ-cyclodextrin (BA-CyD) was synthesized as a hybrid cross-linker of polyvinyl alcohol (PVA) to form a new type of hydrogel. The CyD moiety of BA-CyD forms an inclusion complex with the PVA chain to produce a mechanically interlocking structure. At the same time, the BA moiety of BA-CyD forms covalent bonds with the 1,3-diol moieties of PVA. On the basis of these two modes of interaction, the hybrid cross-linker connects two PVA chains, thus resulting in the formation of a hydrogel. To investigate the possibility of this hydrogel becoming the basis for an intelligent material for drug delivery, sugar-responsive drug release from the hydrogel was demonstrated. [ABSTRACT FROM AUTHOR]

There is a common phenomenon that the heterogeneity of natural oligosaccharides contains various sugar units, which can be used to enhance affinity and selectivity toward a specific receptor, so the synthesis of heterogeneous glycopolymers is always an important issue in the glycopolymer field. Herein, this study conducts a one-pot method to prepare polyrotaxane-based heteroglycopolymers anchored with different sugar units and fluorescent moieties via the combination of host-guest interaction, thiol-ene, and copper-catalyzed click chemistry in water. Fourier transform infrared spectroscopy, nuclear magnetic resonance spectroscopy, gel permeation chromatography, X-ray diffraction, and Ellman's assay test are used in the paper to characterize the compounds. Quartz crystal microbalance-dissipation (QCD-D) experiments and bacterial adhesion assay are utilized to study the interactions of polyrotaxane-based heteroglycopolymers with Con A and Escherichia coli. The results reveal that polyrotaxanes (PRs) with mannose and glucose present better specificity toward Con A and E. coli than PRs with glucose due to synergistic effects. [ABSTRACT FROM AUTHOR]

Sulfonated-polyrotaxane (PRX)-coated surfaces with tethered bone morphogenetic protein-2 (BMP-2) were designed for inducing osteogenic differentiation of MC3T3-E1 cells (preosteoblasts). Sulfonated-PRX triblock copolymers composed of sulfopropyl ether-modified α-cyclodextrins (α-CDs) threaded onto a poly(ethylene glycol) (PEG) chain as a PRX segment and poly(benzyl methacrylate) (PBzMA) at both terminals of the PEG as anchoring segments were synthesized by reversible addition-fragmentation chain transfer (RAFT) polymerization. BMP-2 tethering on the PRX surfaces with a large number of threaded α-CDs was suitable for the proliferation of MC3T3-E1 cells, regardless of the presence or absence of sulfopropyl groups. However, the differentiation of MC3T3-E1 cells according to mineralization assays and the gene expression levels of runt-related transcription factor 2, alkaline phosphatase, and osteocalcin was markedly enhanced by BMP-2 tethering on the sulfonated-PRX surface. These results suggest that sulfonated-PRX surfaces can effectively promote the proliferation and induce the osteogenic differentiation of MC3T3-E1 cells by the number of threaded α-CDs and tethered-BMP-2 using electrostatic interactions with sulfopropyl groups. [ABSTRACT FROM PUBLISHER]

We developed stimuli-labile polyrotaxanes (PRXs) composed of β-cyclodextrin (β-CD), Pluronic as an axle polymer, and acid-cleavableN-triphenylmethyl groups as bulky stopper molecules, and found that the PRXs are potent therapeutics for Niemann-Pick type C disease, because the PRX can effectively reduce intracellular cholesterol through the intracellular release of threaded β-CDs. In general, the PRXs need to be chemically modified with hydrophilic functional groups because PRXs are not soluble in aqueous media. Herein, four series of oligo(ethylene glycol)s (OEGs) with different ethylene glycol repeating unit (2 or 3) and chemical structure of OEG terminal (hydroxy or methoxy) were modified onto the threaded β-CDs in PRX. The effects of the structure of OEG on the aqueous solubility, toxicity, and cellular internalization efficiency of OEG-modified PRXs were investigated to optimize the chemical structure of OEG. The hydroxy-terminated OEG-modified PRXs showed excellent solubility in aqueous media and no toxicity, regardless of the number of ethylene glycol repeating units. In the case of the methoxy-terminated OEG-modified PRXs, sufficient solubility in aqueous media and negligible toxicity were observed when the number of ethylene glycol repeating units was 3, while low solubility and toxicity were observed when the ethylene glycol repeating unit was 2. Additionally, cellular uptake levels of methoxy-terminated OEG-modified PRXs in RAW264.7 cells were higher than those of hydroxy-terminated OEG-modified PRXs. Consequently, the chemical structure of the OEG strongly affects the chemical and biological properties of the PRXs, and that a methoxy-terminated OEG with 3 ethylene glycol repeating units is the most preferable modification of PRXs, since the resultant PRX is sufficiently soluble in aqueous media, non-toxic, and possesses high cellular internalization efficiency. [ABSTRACT FROM PUBLISHER]

One of the most interesting phenomena in coordination polymers (CPs) is the co-existence of different interlaced motifs. However, CPs having two different interlaced motifs at the same time are still rare. Colourless block-shaped crystals of the two-dimensional polymer poly[[aqua(μ2-naphthalene-2,6-dicarboxylato){μ2-4,4′-[oxybis(4,1-phenylene)]dipyridine}cadmium(II)] monohydrate], {[Cd(C12H6O4)(C22H16N2O)(H2O)]·H2O} n, (I), was synthesized under hydrothermal conditions by the self-assembly of 4,4′-[oxybis(4,1-phenylene)]dipyridine (OPY) with CdII in the presence of naphthalene-2,6-dicarboxylic acid (H2ndc). Each CdII ion is six-coordinated by two N atoms from the pyridine rings of two OPY ligands and by four O atoms, three of which are from two ndc2− ligands and one of which is from a water molecule. In (I), every two identical two-dimensional (2D) 63 layers are interpenetrated in a parallel fashion, resulting in an interesting 2D→2D framework with both polyrotaxane and polycatenane characteristics. The extension of these sheets into a three-dimensional supramolecular net is via O-H...O hydrogen bonds. The solid-state photoluminescence properties of (I) are also discussed. [ABSTRACT FROM AUTHOR]