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As a natural "binder," lignin fixes cellulose in plants to foster growth and longevity. However, isolated lignin has a poor binding ability, which limits its biomedical applications. In this study, inspired by mussel adhesive proteins, acidic/basic amino acids (AAs) are introduced in alkali lignin (AL) to form ionic-π/spatial correlation interactions, followed by demethylation to create catechol residues for enhanced adhesion activity. Atomic force microscopy reveals that catechol residues are the primary adhesion structures, with basic AAs exhibiting superior synergistic effects compared to acidic AAs. Demethylated lysine-grafted AL exhibits the strongest adhesion force toward skin tissue. Molecular dynamic simulation and density functional theory calculations indicate that adhesion against skin tissue mainly results from hydrogen bonds and cation-π interactions, with the adhesion mechanism being based on the Gibbs free energy of the Schiff base reaction. In summary, a biomimetic electrode based on lignin inspired by mussel adhesive proteins is prepared; the presented method offers a straightforward strategy for the development of biomimetic adhesives. Furthermore, this mussel-inspired adhesive can be used as a wearable bioelectrode in biomedical applications., (© 2024 Wiley‐VCH GmbH.)

Hydrogels with fascinating adhesion have been demonstrated great potential in various applications. However, most hydrogels lose their adhesion in wet or underwater environments due to the influence of interfacial water. Inspired by mussel, an underwater adhesive hydrogel was facilely fabricated by introducing electrostatic interactions, which consisted of poly (acrylic acid) (PAA), quaternized xylan (QAX) and tannic acid (TA). In this hydrogel, -COO - from PAA, -N + (CH 3 ) 3 from QAX and catechol group from TA resembled amino acids with negative and positive charges and 3,4-dihydroxyphenylalanine units in mussel, which endowed the hydrogels with great underwater adhesion through multiple interactions. Notably, acrylic acid (AA) played a key role in the dispersion of the system. QAX, a biomass derived from plants with excellent properties, worked with PAA to construct hydrogel networks. The resultant hydrogels exhibited excellent mechanical properties including remarkable stretchability (>4000 %) and compressibility. Moreover, the hydrogels had superior UV-blocking (~99.96 %), and showed good adhesion both in air and underwater. The hydrogels can be exploited as a wearable sensor to monitor human motions and even subtle motions, which have the potential to be explored in human health monitoring., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier B.V. All rights reserved.)

We report an ingenious technique to prepare magnetic alkaline lignin-dopamine nanoparticles (AL-DA/Fe 3 O 4 NPs). Alkaline lignin, a kind of abundant waste from agriculture, pulping and bio-energy industry, was functionalized by the conjugation with DA molecules and nano-precipitation method. Benefiting from the three-dimensional network of lignin and mussel-inspired DA molecules, chromium(III) can be effectively removed by physisorption and chemisorption. The maximum Cr(III) adsorption capacity of AL-DA/Fe 3 O 4 NPs was found to be 44.56 mg/g, which was among the highest of previously reported biomass-based Cr(III) adsorbents. Moreover, sensitive magnetic responsiveness (24.6 emu/g) of AL-DA/Fe 3 O 4 NPs can be more helpful in recycling (over 90% recycled within 2 min) and multiple reusing. The preparation of this low-cost, high adsorptive capacity and good ecofriendly lignin-based nano-adsorbent is expected to become a sustainable technology to simultaneously achieve the wastewater reutilization from pulping and bio-energy industry and purification of other modern industries., (Copyright © 2019 Elsevier B.V. All rights reserved.)

On three occasions between 1998 and 2000, freshwater mussels were collected by divers in Lake Memphremagog during the spring and transplanted to various locations in the St-François River (Quebec, Canada). Mussel growth was monitored by comparing total weight and length at the beginning and end of the exposure period. In 1998, mussels were caged for 60 days at 10 stations, including locations receiving treated effluents from three pulp and paper mills. Overall, there was an apparent trend of increased mussel growth from upstream to downstream along the river. However, mussels caged downstream from the effluent discharge of a bleached kraft pulp and paper mill grew more slowly than those caged immediately upstream in the river. In 1999 and 2000, we further investigated the situation in the vicinity of this bleached kraft mill. The measurements again indicated that growth of mussels in the effluent plume from this mill was reduced in comparison to sites upstream. Overall, in terms of growth, the caged mussels responded both positively and negatively to different environmental conditions. Compared with other monitoring approaches used at these sites during the same period, the caged mussel experiment results were consistent with the trends observed with the benthic invertebrate survey but not with the trends observed for fish.