Polymer Journal

Narikiyo, Hayato; Gon, Masayuki; Tanaka, Kazuo; Chujo, Yoshiki

doi: 10.1038/s41428-024-00909-6pmid: N/A

Since anions play a significant role in various biological phenomena, developing fluorescence anion sensors is important. Previously, we focused on polyhedral oligomeric silsesquioxane (POSS) as a three-dimensional (3D) scaffold to design an anion receptor. In this study, we evaluated the anion binding properties of an POSS derivative with eight urea groups and applied the derivative to an anion fluorescence sensor utilizing its 3D structure. 1H NMR measurements revealed that the POSS derivative with urea groups can bind to sulfate ions. Compared to the model compound, the POSS derivative exhibits a greater binding ability due to the cooperative effects of multiple urea groups. Through the introduction of naphthyl urea groups, the POSS derivative can be used as a fluorescence sensor for quantifying sulfate ions.

Nomura, Kota; Fujita, Seiya; Shimatani, Yuki; Kurita, Taichi; Thagun, Chonprakun; Abe, Naoya; Oikawa, Kazusato; Tsuchiya, Kousuke; Uji, Hirotaka; Numata, Keiji

doi: 10.1038/s41428-024-00901-0pmid: N/A

An important method for plant genetic modification is using peptide/pDNA complexes to transfer genes into plant cells. With conventional carrier peptides, the peptide sequence must contain a high amount of cationic amino acids to condense and introduce pDNA. As a result, the dissociation of pDNA from the complex is inefficient, often causing problems. Herein, we designed a new peptide carrier that mimics the basic leucine zipper (bZIP) domain of DNA-binding proteins, in which (LU)4 is the leucine zipper motif and (KUA)3 is the basic DNA-binding and cell-penetrating motif (U = α-aminoisobutyric acid). After (KUA)3-(LU)4 peptide was mixed with pDNA, DNA molecules were condensed to form nanoparticles of approximately 130 nm. Furthermore, when complexes of (KUA)3-(LU)4 peptide and pDNA were introduced into the leaves of Arabidopsis thaliana (A. thaliana), expression of the reporter protein was detected in the plant cells. Thus, (KUA)3-(LU)4 peptide that mimics the bZIP domain is a novel and efficient carrier for pDNA with high dissociation efficiency.

Uchida, Haruki; Uchiyama, Wakako; Kurita, Erika; Kirihara, Masayuki; Kotsuchibashi, Yohei

doi: 10.1038/s41428-024-00897-7pmid: N/A

Water-insoluble micropatterned films were prepared from poly(vinyl alcohol) (PVA) (or ethylene-vinyl alcohol copolymer (EVOH)) and poly(methacrylic acid) (poly(MAAc)). The carboxy groups in poly(MAAc) underwent dehydration reactions with the hydroxy groups in the vinyl alcohol units during heating at 135 °C, which resulted in crosslinking with ester bonds and formation of a polymeric network in the micropatterned films. The surface structures of the micropatterned films and the shapes of the peeled microplastics in the supernatant were measured after decomposition in an oxidizing environment, after ultrasonic irradiation, and with both. The results revealed that the micropatterns could be peeled off from the films after they were subjected to appropriate decomposition conditions and maintained their patterned shapes.

Kobayashi, Ryunosuke; Naito, Mitsuru; Miyata, Kanjiro; Sakai, Takamasa; Chung, Ung-il; Katashima, Takuya

doi: 10.1038/s41428-024-00902-zpmid: N/A

In this study, we utilized tetra-armed polyethylene glycol (Tetra-PEG) slimes, which are model transient networks with well-controlled structures, to predict the effects of long-term degradation on the viscoelastic properties of liquids. Viscoelastic liquids, such as sodium hyaluronate, are frequently used in biomedical applications within the human body. However, precisely controlling the viscoelastic properties of these liquids in the long-term is challenging, as the main chains of the liquids undergo stochastic degradation. To establish a predictable model for studying long-term degradation effects, we employed Tetra-PEG slime, and modifications were performed to introduce specific cleavage sites in areas with connections. The Tetra-PEG slimes were characterized by single relaxation modes, and these modes were independent from the degree of degradation, which was determined by hydrolyzing the cleavage sites. Overall, this work provides a universal design for viscoelastic liquids with precisely-controllable degradation.

Inagaki, Shin; Nakabayashi, Kazuhiro; Higashihara, Tomoya

doi: 10.1038/s41428-024-00898-6pmid: N/A

Semiconducting polymers have garnered considerable attention from researchers, as these polymers are potentially applicable to flexible/stretchable organic electronics. However, although the adhesiveness of these materials on substrates is an important characteristic, it has rarely been investigated. Herein, we synthesized and characterized a novel block copolymer, poly(3-hexylthiophene)-b-poly(vinyl catechol) (P3HT-b-PVC), with improved adhesion properties. P3HT-b-PVC was successfully synthesized via a copper-catalyzed azide–alkyne cycloaddition reaction between chain-end-functionalized P3HT with an alkyne group (P3HT-Alkyne) and chain-end-functionalized poly(3,4-di-tert-butyldimethylsilyloxystyrene) with an azide group (PSVC-Azide), followed by deprotection of tert-butyldimethylsilyloxy groups from the PSVC-Azide segment. Tape test results showed that the adhesion property of the P3HT-b-PVC film was considerably better than that of the corresponding P3HT film. Furthermore, despite the presence of an insulating PVC block in P3HT-b-PVC, the P3HT-b-PVC thin film exhibited a hole mobility of 1.1 × 10−5 cm2V−1s−1, which was comparable to that of the corresponding P3HT thin film (1.8 × 10−5 cm2V−1s−1). To the best of our knowledge, this is the first study to elucidate the primitive adhesion properties and charge mobility of P3HT-based block copolymers. The proposed synthetic approach may be extended to develop various block copolymers with other π-conjugated polymer segments, providing new avenues for various applications that require highly-adhesive materials.

Takahashi, Rina; Udagawa, Taro; Hashimoto, Kei; Kutsumizu, Shoichi; Miwa, Yohei

doi: 10.1038/s41428-024-00907-8pmid: N/A

The effect of the ratio of divalent (Mg2+) to monovalent (Na+) cations on the mechanical and self-healing properties of polyisoprene (PI) ionomers co-neutralized with Na+ and Mg2+ was studied. Sodium carboxylates link polymer chains via electrostatic interactions, while magnesium carboxylates more strongly link polymer chains via ionic bonds. Therefore, Mg2+ considerably reinforces the PI ionomer. However, we found that the mechanical properties of the PI ionomers did not change proportionally to the ratio of Mg2+. The ionomer was significantly reinforced at over 25% of the Mg2+ ratio, where linkage via Mg2+ in the network was prevalent throughout the material. At the same time, the self-healing of the PI ionomer was disrupted.

Araki, Jun; Yoda, Shiori; Kudo, Riku

doi: 10.1038/s41428-024-00904-xpmid: N/A

Surface amino groups (SAGs) on chitin nanowhiskers and chitin nanofibers were rapidly and facilely quantified via spectrophotometry using three amino-labeling reagents (2,4,6-trinitrobenzensulfonic acid sodium salt (TNBS), o-phthalaldehyde (OPA) and ninhydrin) and two cationic dyes (reactive red 4 (RR4) and acid orange 7 (AO7)). After binding to the SAGs, the amounts of excess TNBS and OPA were determined via spectrophotometry and subtracted from the initial quantity. After ninhydrin was added to ChNWs/ChNFs, Ruhemann’s purple product was generated, which was quantified via spectrophotometry. When RR4 and AO7 were added in excess to the SAG of ChNWs/ChNFs, these dyes were adsorbed onto surface amino groups, and the excess amounts were similarly quantified. Each method yielded different amino group contents, which were compared with the titration values. Although the values obtained by labeling reagents were considerably underestimated, those obtained using TNBS and ninhydrin were proportional to those obtained by titration. The values obtained using AO7 adsorption at pH 2 or 3 corresponded well with the titration values for ChNWs but not ChNFs. Reliable results were attained using the two former labeling reagents with conversion equations or using AO7 adsorption.