- Robust magnetic double-network hydrogels with self-healing, MR imaging, cytocompatibility and 3D printability
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Herein, we have fabricated a novel robust self-healing magnetic double-network hydrogel by multiple interactions between bondable magnetic Fe3O4 and chitosan-polyolefin matrix, and the hydrogel also exhibits an excellent magnetogenic effect and MR imageability. The practical potential of the magnetic double-network hydrogel is further revealed by its 3D-printing performance.
- Gang, Fangli,Yan, Hao,Ma, Chunyang,Jiang, Le,Gu, Yingying,Liu, Ziyu,Zhao, Lingyun,Wang, Xiumei,Zhang, Jiwen,Sun, Xiaodan
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- A clear coat from a water soluble precursor: A bioinspired paint concept
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Traditional paints consist of hydrophobic polymers dissolved in hydrocarbons; they are appreciated for their rheological properties and the smooth and glossy films they form upon drying and crosslinking, but are now largely banned because of the hazards associated with the solvents. In terms of health, water borne paints based on colloidal resin dispersions are an improvement but these systems lack the rheological and film forming properties of traditional paints. We present here a bio-inspired alternative that combines the best of both worlds: a water soluble polymer that can crosslink by mild oxidation to a fully water resistant and adhesive coating. Using free radical polymerization, we copolymerized two water soluble monomers, namely borax-protected dopamine acrylamide (DAA-p) and 2-aminoethylmethacrylamide (AEMA) in various proportions. We determined the reactivity ratio of these monomers using an in situ1H NMR monitoring method and found values of 0.0 and 0.46 for DAA-p and AEMA, respectively. From this we conclude that in the polymers DAA-p pairs do not occur, while DAA-AEMA diads are relatively frequent. After removing the protective borax by hydrolysis, we obtain polymers which are soluble in water at low pH (pH 2) but which undergo rapid oxidative crosslinking when the catechol groups of DAA react with amines from AEMA. This leads to a water resistant, mildly hydrophobic film with a water/air contact angle of about 40 degrees which adheres well to glass substrates.
- Yang, Juan,Bos, Inge,Pranger, Wim,Stuiver, Anthonie,Velders, Aldrik H.,Cohen Stuart, Martien A.,Kamperman, Marleen
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- Carbohydrate-Responsive Surface Adhesion Based on the Dynamic Covalent Chemistry of Phenylboronic Acid- and Catechol-Containing Polymer Brushes
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A glue, based on dynamic covalent chemistry, with a strong adhesion (2.38 kg cm?2), water resistance and carbohydrate responsive reversibility is presented. Using surface initiated atom transfer radical polymerization (SI-ATRP), glass and silicon surfaces were coated with copolymers functionalized with phenylboronic acids and catechols. In combination with microcontact printing (μCP) these polymer brushes give access to a carbohydrate responsive “supramolecular Velcro”.
- Lamping, Sebastian,Otremba, Tobias,Ravoo, Bart Jan
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- Effect of Substituents in Mussel-inspired Surface Primers on their Oxidation and Priming Efficiency
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Marine mussels contain an abundant catechol moiety, 3,4-dihydroxyphenylalanine (DOPA), in their interfacial foot proteins. DOPA contributes to both surface adhesion and bridging between the surface and overhead proteins (surface priming) by taking advantage of the unique redox properties of catechol. Inspired by the mussel surface priming mechanism, herein we synthesized a series of DOPA-mimetic analogs – a bifunctional group molecule, consisting of a catechol group and an acrylic group at the opposite ends. The surface primers with differently substituted (?COOH, ?CH3) alkyl chains in the middle spacer were synthesized. Time-dependent oxidation and redox potentials of the surface primers were studied in an oxidizing environment to gain a better understanding of the mussel‘s redox chemistry. The thickness and degree of priming of the surface primers on silicon-based substrates were analyzed by ellipsometry and UV/Vis absorption spectroscopy. The post-reactivity of the acrylic groups of the primed layer was first visualized through a reaction with an acrylic group-reactive dye.
- Ganesh, Karuppasamy,Jung, Jaewon,Kim, Byeong-Su,Seo, Sungbaek,Woo Park, Jun
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p. 852 - 859
(2021/08/30)
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- Cooperativity of Catechols and Amines in High-Performance Dry/Wet Adhesives
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The outstanding adhesive performance of mussel byssal threads has inspired materials scientists over the past few decades. Exploiting the amino-catechol synergy, polymeric pressure-sensitive adhesives (PSAs) have now been synthesized by copolymerizing tra
- Delparastan, Peyman,Gerst, Matthias,Messersmith, Phillip B.,Ney, Max R.,Tiu, Brylee David B.
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supporting information
p. 16616 - 16624
(2020/08/03)
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- Nucleotides and aptamers containing boronic acid groups having biased binding to glycosylated proteins, and uses thereof
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The present disclosure encompasses oligonucleotide aptamers selectively binding a target glycosylated polypeptide or protein, and having biased affinity for the glycan through a boronic acid linked to a nucleosidic base of a nucleotide(s). The disclosure further encompasses methods for isolating an aptamer(s) selectively binding a target glycosylated polypeptide, where, from a population of randomized oligonucleotides that have at least one nucleotide having a boronic acid label linked to a base, is selected a first subpopulation of aptamers binding to the target glycosylated polypeptide or protein. This subpopulation is then amplified without using boronic acid-modified TTP, and amplification products not binding to a target glycosylated polypeptide or protein are selected. The second subpopulation of aptamers is then amplified using boronic acid-modified TTP to provide a population of boronic acid-modified aptamers capable of selectively binding to a glycosylation site of a target polypeptide or protein. Other aspects of the disclosure encompass methods for the use of the modified aptamers to detect glycosylated species of a polypeptide or protein.
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- Gelation and adhesion behavior of mussel adhesive protein mimetic polymer
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An acrylamide-type copolymer containing catechol, amino, and hydroxyl groups was synthesized as a mimetic of the natural mussel adhesive protein (MAP). The obtained copolymer in a phosphate buffer solution (pH = 8.0) formed a hydrogel within 2 h under air, whereas gelation did not proceed under argon atmosphere. We confirmed that the cross-linking reaction of the synthesized MAP mimetic copolymer was triggered by aerobic oxidation of catechol moieties to form an adhesive hydrogel. Two aluminum plates were adhered by the gelation of the MAP mimetic copolymer solution under humid air at room temperature. The interfacial region between the two aluminum plates failed at a lap shear strength of 0.46 MPa due to cohesive failure of the hydrogel. The adhesion strength was dominated by mechanical strength of the hydrogel as well as the interface interaction of catechol groups with substrate surface. 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2013. Copyright
- Nishida, Jin,Kobayashi, Motoyasu,Takahara, Atsushi
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p. 1058 - 1065
(2013/03/28)
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