Microfluidic-Generated Injectable Bulking Agents with Biocompatible Surfaces and Their Mid-term Outcomes in a Rat Model with Anal Sphincter Injury.

Bulking agents have gained attention as new, minimally invasive treatments for fecal incontinence. Various materials and surface treatment techniques have been extensively studied to ensure good biocompatibility and long-term stability. Despite significant improvements in biocompatibility, the nonuniform particle size of existing materials has led to other challenges, such as the induction of phagocytosis or reduction of injectability during in vivo tests.

Effects of a Mechanically Interlocked Structure on Ionic Conductivity in Polyrotaxane-Based Polymer Electrolytes.

Polyrotaxane (PR) is a mechanically interlocked polymer (MIP) utilized as an electrolyte because of its distinctive property of dynamic molecular mobility. While numerous studies have concentrated on modifying external properties to decrease high crystallinity, few have explored the control of intrinsic properties. This study examines the crystalline properties and molecular mobility of PR-based electrolytes, along with their effects on ionic conductivity, by manipulating intrinsic properties.

Aligned Ion Conduction Pathway of Polyrotaxane-Based Electrolyte with Dispersed Hydrophobic Chains for Solid-State Lithium-Oxygen Batteries.

A critical challenge hindering the practical application of lithium-oxygen batteries (LOBs) is the inevitable problems associated with liquid electrolytes, such as evaporation and safety problems. Our study addresses these problems by proposing a modified polyrotaxane (mPR)-based solid polymer electrolyte (SPE) design that simultaneously mitigates solvent-related problems and improves conductivity. mPR-SPE exhibits high ion conductivity (2.

Mechanically Robust Cellulose-Based Piezoelectric Elastomer Formed by Slidable Polyrotaxane Cross-Linker.

Cellulose has great potential in the field of piezoelectricity owing to its high crystallinity; however, it exhibits low processability and poor mechanical robustness. In this study, to enhance the applicability of cellulose-based piezoelectric materials, a robust cellulose-based piezoelectric elastomer with excellent piezoelectric properties was developed by cross-linking cellulose with polyrotaxane (PR). The effects of cross-linking on the mechanical properties and crystalline structures of the resulting elastomers were investigated.

Physical Properties of Poly(ether-thiourea)-Based Elastomer Formed by Zigzag Hydrogen Bonding and Slidable Cross-Linking.

In this study, the effects of zigzag hydrogen bonding and slidable cross-linking on the design of stretchable elastomers were explored. Poly(ether-thiourea) (TU), capable of generating strong zigzag hydrogen bonds without crystallization, was introduced as the main chain in the non-cross-linked region of the developed elastomer. Consequently, the toughness of the TU-based elastomer was 14 times higher than that of elastomers formed using linear poly(ethylene glycol), despite the relatively low molecular weight of TU (∼3k).

Slidable Cross-Linking Effect on Liquid Crystal Elastomers: Enhancement of Toughness, Shape-Memory, and Self-Healing Properties.

The network structures of liquid crystal elastomers (LCEs) are crucial to impart rubbery behavior to LCEs and enable reversible actuation. Most LCEs developed to date are covalently linked, implying that the cross-links are fixed at a particular position. Herein, we report a new class of LCEs integrating polyrotaxanes (PRs) as slidable cross-links (PR-LCEs).

Enhanced osteogenic differentiation of mesenchymal stem cells by surface lithium modification in a sandblasted/acid-etched titanium implant.

This study investigated the osteogenesis-related cell functions of osteoprogenitor cells modulated by surface chemistry modification using lithium (Li) ions in a current clinical oral implant surface in order to gain insights into the future development of titanium (Ti) implants with enhanced osteogenic capacity. Wet chemical treatment was performed to modify a sandblasted/acid-etched (SLA) Ti implant surface using Li ions. The osteogenesis-related cell response to the surface Li ion-modified SLA sample was evaluated using two kinds of murine bone marrow stem cells, bipotent ST2 cells and primary multipotent mesenchymal stem cells (MSCs).

Optimization of Anisotropic Crystalline Structure of Molecular Necklace-like Polyrotaxane for Tough Piezoelectric Elastomer.

While piezoelectric materials are applied in various fields, they generally exhibit poor mechanical toughness. To increase the applicability of these, their mechanical properties need to be improved. In this study, a tough piezoelectric polyrotaxane (PRX) elastomer was developed by blending PRX samples of two different lengths, formed using 10K and 35K poly(ethylene glycol), to align dipole moments for optimization of the piezoelectricity characteristics.

Preclinical testing of an anal bulking agent coated with a zwitterionic polymer in a fecal incontinence rat model.

Fecal incontinence is a disabling condition in which the passage of fecal material cannot be controlled. Although the condition is not life-threatening, it can seriously reduce the quality of life of a patient by isolating them from others. Though various surgical treatments are available for moderate to severe symptoms, a bulking agent is a minimally invasive technique that has attracted attention because of its safety and simple treatment process.

Injectable polydimethylsiloxane microfiller coated with zwitterionic polymer for enhanced biocompatibility.

Silicone-based fillers have been applied in several branches of medicine, such as soft tissue augmentation, because of their stability and durability. However, the inherently hydrophobic surfaces of silicone occasionally cause excessive deposition of the fibrous matrix in vivo, leading to severe fibrosis. In this study, we evaluated the use of a zwitterionic copolymer to offer a facile surface treatment method for silicone-based fillers and performed a preclinical trial of the formulation as-prepared.

Scratch Properties of Clear Coat for Automotive Coating Comprising Molecular Necklace Crosslinkers with Silane Functional Groups for Various Environmental Factors.

Automotive coatings, which comprise multiple layers, i.e., primer, base coating, and clear coat layers, are exposed to various environmental conditions that pose various types of damages to them.

Mechanical Durability of Flexible Printed Circuit Boards Containing Thin Coverlays Fabricated with Poly(Amide-Imide-Urethane)/Epoxy Interpenetrating Networks.

Because electronics are becoming flexible, the demand for techniques to manufacture thin flexible printed circuit boards (FPCBs) has increased. Conventional FPCBs are fabricated by attaching a coverlay film (41 μm) onto copper patterns/polyimide (PI) film to produce the structure of coverlay/Cu patterns/PI film. Given that the conventional coverlay consists of two layers of polyimide film and adhesive, its thickness must be reduced to generate thinner FPCBs.

Phosphorylcholine-based encoded hydrogel microparticles with enhanced fouling resistance for multiplex immunoassays.

Due to the growing interest in multiplex protein detection, encoded hydrogel microparticles have received attention as a possible path to high performance multiplex immunoassays through a combination of high multiplexing capability and enhanced binding kinetics. However, their practical operation in real complex samples is still limited because polyethylene glycol, which is the main component of hydrogel particles, suffers from oxidative damage and relatively high fouling properties in biochemical solutions. Here, we introduce poly(2-methacryloyloxyethyl phosphorylcholine) (PMPC)-based encoded hydrogel microparticles to perform fouling-resistant multiplex immunoassays, where the anti-fouling characteristics are attributed to the zwitterionic PMPC.

Covalently Grafted 2-Methacryloyloxyethyl Phosphorylcholine Networks Inhibit Fibrous Capsule Formation around Silicone Breast Implants in a Porcine Model.

The surface of human silicone breast implants is covalently grafted at a high density with a 2-methacryloyloxyethyl phosphorylcholine (MPC)-based polymer. Addition of cross-linkers is essential for enhancing the density and mechanical durability of the MPC graft. The MPC graft strongly inhibits not only adsorption but also the conformational deformation of fibrinogen, resulting in the exposure of a buried amino acid sequence, γ377-395, which is recognized by inflammatory cells.

Enhanced Mechanical Strength, Flexibility, and Shape-Restoring Rate of a Drug-Eluting Shape-Memory Polymer by Incorporation of Supramolecular Cross-Linkers.

The purpose of this study is to develop mechanically robust soybean oil and polycaprolactone (PC)-based drug-eluting shape memory polymers (SMPs) containing polyrotaxane (PRX) cross-linkers. Essentially, the dynamic PRX cross-linker-containing methacrylate group is introduced to increase the cross-linking density and flexibility of the SMP to overcome its mechanical limitations. It was confirmed that the elongation and cross-linking density of the PRX-incorporated SMP were increased by 2-4 times compared to neat SMP.

Mechanically Reinforced Gelatin Hydrogels by Introducing Slidable Supramolecular Cross-Linkers.

Tough mechanical properties are generally required for tissue substitutes used in regeneration of damaged tissue, as these substitutes must be able to withstand the external physical force caused by stretching. Gelatin, a biopolymer derived from collagen, is a biocompatible and cell adhesive material, and is thus widely utilized as a component of biomaterials. However, the application of gelatin hydrogels as a tissue substitute is limited owing to their insufficient mechanical properties.

Foldable and Extremely Scratch-Resistant Hard Coating Materials from Molecular Necklace-like Cross-Linkers.

A flexible hard coating material displaying extreme scratch resistance and foldable flexibility was developed via the design of an organic-inorganic hybrid coating material employing an alkoxysilyl-functionalized polyrotaxane cross-linker (PRX_Si1). PRX_Si1 has a molecular necklace-like structure that can form organic-inorganic cross-linking points and provide large molecular movements. It was postulated that the scratch resistance and flexibility could be simultaneously increased because of the hybrid cross-linking points and dynamic molecular movements.

Calcium-Binding Polymer-Coated Poly(lactide- co-glycolide) Microparticles for Sustained Release of Quorum Sensing Inhibitors to Prevent Biofilm Formation on Hydroxyapatite Surfaces.

Quorum sensing (QS) inhibitor-based therapy is an attractive strategy to inhibit bacterial biofilm formation without excessive induction of antibiotic resistance. Thus, we designed Ca-binding poly(lactide- co-glycolide) (PLGA) microparticles that can maintain a sufficient concentration of QS inhibitors around hydroxyapatite (HA) surfaces in order to prevent biofilm formation on HA-based dental or bone tissues or implants and, therefore, subsequent pathogenesis. Poly(butyl methacrylate- co-methacryloyloxyethyl phosphate) (PBMP) contains both Ca-binding phosphomonoester groups and PLGA-interacting butyl groups.

Developing a thermal grafting process for zwitterionic polymers on cross-linked polyethylene with geometry-independent grafting thickness.

To overcome the drawbacks of the UV grafting method, an alternative, thermal grafting process is suggested. The uniform and geometry-independent grafting of zwitterionic polymers on curved cross-linked polyethylene (CLPE), which is used in artificial hip joints, surface was successfully achieved. Poly(2-methacryloyloxyethyl phosphorylcholine) (PMPC) and poly(2-(methacryloyloxy)ethyl)dimethyl(3-sulfopropyl)ammonium hydroxide) (PMEDSAH) were grafted on the CLPE by two methods: a UV-based process and a thermal process.

Surface-Restructuring Differences between Polyrotaxanes and Random Copolymers in Aqueous Environment.

In the present study, we investigated the surface reorganization behaviors and adsorption conformations of fibrinogen on the surface of polyrotaxanes containing different amounts of α-cyclodextrin (α-CD) by using surface-sensitive vibrational spectroscopy sum frequency generation (SFG). For comparison, behaviors of the surface restructuring and fibrinogen adsorption on the random copolymers containing similar terminal groups were also investigated. It was found that larger amounts of BMA moieties of polyrotaxanes form ordered surface structures after immersion in water for 48 h.

Urban Planning and Smart City Decision Management Empowered by Real-Time Data Processing Using Big Data Analytics.

The Internet of Things (IoT), inspired by the tremendous growth of connected heterogeneous devices, has pioneered the notion of smart city. Various components, i.e.

One-Pot Synthesis of a Zwitterionic Small Molecule Bearing Disulfide Moiety for Antibiofouling Macro- and Nanoscale Gold Surfaces.

The goal of this study is to develop a simple one-pot method for the synthesis of a zwitterionic small molecule bearing disulfide moiety, which can effectively inhibit nonspecific protein adsorption on macroscopic and nanoscopic gold surfaces. To this end, the optimal molecular structure of a pyridine disulfide derivative was explored and a zwitterionic small molecule was successfully synthesized from the tertiary amine residue on the pyridine ring through a one-pot method. The coating conditions of the synthesized zwitterionic molecules on the gold surface were optimized through contact angle measurements, and the strong interactions between the gold surface and the disulfide moiety of the zwitterion small molecule were confirmed by surface plasmon resonance (SPR) analysis and X-ray photoelectron spectroscopy.

Anti-inflammatory and Antibacterial Effects of Covalently Attached Biomembrane-Mimic Polymer Grafts on Gore-Tex Implants.

Expanded polytetrafluoroethylene (ePTFE), also known as Gore-Tex, is widely used as an implantable biomaterial in biomedical applications because of its favorable mechanical properties and biochemical inertness. However, infection and inflammation are two major complications with ePTFE implantations, because pathogenic bacteria can inhabit the microsized pores, without clearance by host immune cells, and the limited biocompatibility can induce foreign body reactions. To minimize these complications, we covalently grafted a biomembrane-mimic polymer, poly(2-methacryloyloxylethyl phosphorylcholine) (PMPC), by partial defluorination followed by UV-induced polymerization with cross-linkers on the ePTFE surface.

Fabrication of an Anti-Biofouling Plasma-Filtration Membrane by an Electrospinning Process Using Photo-Cross-linkable Zwitterionic Phospholipid Polymers.

The goal of this study is to fabricate a stable plasma filtration membrane with antibiofouling properties via an electrospinning process. To this end, a random-type copolymer consisting of zwitterionic phosphorylcholine (PC) groups and ultraviolet (UV)-cross-linkable phenyl azide groups was synthesized. The zwitterionic PC group provides antibiofouling properties, and the phenyl azide group enables the stable maintenance of the fibrous nanostructure of hydrophilic zwitterion polymers in aqueous medium via a simple UV curing process.