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Local drug delivery has generated considerable interest due to its controlled and sustained drug release at the target site on demand. Nanoaggregate-incorporated composite hydrogels are desirable as local drug delivery systems; however, it is difficult to achieve sustained and controlled hydrophobic drug release and superior mechanical properties in one system. Herein, a "smart" composite hydrogel was synthesized by incorporating hemicellulose-based nanoaggregates into a double network consisting of alginate/Ca 2+ and polyacrylic acid-co-dimethylaminoethyl methacrylate [P(AA-co-DMAEMA)]. Hemicellulose-based nanoaggregates were assembled from xylan-rich hemicellulose laurate methacrylate (XH-LA-MA) polymers and entrapped into the hydrogel framework via chemical fixation. Another composite hydrogel with physically embedded hemicellulose laurate (XH-LA) nanoaggregates was prepared as a comparison. Accordingly, covalently cross-linked XH-LA-MA nanoaggregates in hydrogels resulted in a denser pore structure and reinforced mechanical properties. Nanoaggregate diffusion analysis revealed that covalent bonding between the nanoaggregates and the hydrogel framework contributed to prolonged diffusion behavior. Curcumin (Cur)-loaded XH-LA-MA composite hydrogels enabled sustained Cur release in simulated body fluid and showed stimulus responsiveness toward ethylenediaminetetraacetic acid (EDTA) and/or glutathione (GSH). All the composite hydrogels were biocompatible, as verified by Cell Counting Kit-8 (CCK-8) assay against NIH/3T3 cells. These composite hydrogels hold great potential as a promising dosage form for biomedical applications., 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 © 2024 Elsevier B.V. All rights reserved.)

Selective fractionation of hemicelluloses is of great significance for realizing high-value application of hemicelluloses and comprehensive utilization of lignocellulosic biomass. Tetramethylammonium hydroxide (TMAH) solvent has been confirmed as a promising solvent to selectively fractionate hemicelluloses from holocellulose. Herein, TMAH solvent was adopted to pretreat poplar thermomechanical pulp (PTMP) for the selective fractionation of hemicelluloses and enhancement of enzymatic hydrolysis performance of residues. The maximal hemicelluloses yield (65.0 %) and excellent cellulose retention rate (93.3 %) were achieved after pretreatment by the 25 wt% TMAH solvent, while the delignification was only 33.9 %. The hemicelluloses fractions could be selectively fractionated with high molecular weights (109,800-118,500 g/mol), the contents of Klason lignin in them were low (3.2-5.9 %), and the dominating structure of them was 4-O-methylglucurono-β-D-xylan. Compared to the H 2 SO 4 and NaOH methods, the hemicelluloses fractionated by TMAH method exhibited higher yields, more complete structures and higher molecular weights. Furthermore, the crystalline structure of cellulose practically remained stable, and the highest yield of enzymatic hydrolysis glucose was 57.5 %, which was 3.3 times of that of PTMP. The fractionation effectiveness of TMAH solvent was not significantly reduced after repeatedly recycling. This work demonstrated TMAH solvent could selectively fractionate hemicelluloses from PTMP and efficiently promote sustainable poplar-based biorefinery., 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 © 2023 Elsevier B.V. All rights reserved.)

It is believed that hemicellulose plays a crucial role in binding cellulose and lignin in plant cells. It may provide significant implications through figuring out the interaction between hemicellulose and microfibers and gaining insights how the structure of hemicellulose affects its association with cellulose nanofibers. Herein, the hemicellulose and nanocellulose fractions from pulps obtained by controlling the H-factors of kraft pulping process were quantitatively evaluated for their adsorption behavior using QCM-D. The results showed that harsher cooking (corresponding to high H-factor) significantly affected the chemical composition of hemicellulose, leading to a decrease of its molecular weight and gradually turning it into a linear structure. Hemicellulose possesses a strong natural affinity for CNC-coated sensors. The hemicellulose from the pulp cooked by high H-factor process decreases its ability to adsorb onto nanocellulose, the adsorption rate also slows down, and the conformation of the adsorbed layer changes which makes the binding weak and reversible. In conclusion, the pulping process in high H-factor significantly changed the structure of hemicellulose, leading to a variation in the strength of its interaction with nanocellulose., 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 © 2024 Elsevier B.V. All rights reserved.)