Xiang Hao

Carbohydrates are increasingly valued as renewable macromolecular resources, particularly because their semicrystalline architectures endow them with distinctive structural and functional properties. While hexose-based crystalline polysaccharides such as cellulose, chitin, and starch have been extensively studied, crystalline xylan, a pentose-based polysaccharide composed of xylose units, has only recently emerged as an underexplored member of this family. Debranching can reduce xylan substitution, enhance backbone regularity, and promote ordered crystalline domains, thereby distinguishing crystalline xylan from amorphous hemicelluloses. This review summarizes recent advances in crystalline xylan, covering its molecular and crystal structures, water-dependent unit-cell behavior, sources, and preparation strategies. Particular attention is given to its conversion into high-value xylan nanocrystals through top-down and bottom-up routes, with emphasis on the relationships among processing methods, nanoscale morphology, and colloidal stability. Finally, emerging applications in optical materials, dispersants, gels, plastics, and related functional systems are discussed, together with current challenges and future opportunities.

Ageing is inevitable and accompanied by progressive loss of skin elasticity. Fibroblasts, embedded within the extracellular matrix, finely regulate skin mechanics via membrane‐bound ligands. Creating synthetic assemblies that mimic fibroblast function is appealing yet challenging. Here, we present a strategy that co‐assembles lignin with divinyl ligands to generate fibroblast‐mimicking polymersomes, enabling precise programming of bulk materials to emulate human skin across distinct physiological stages. Because lignin polymersomes are driven by relatively weak π–π stacking, hydrophobic ligands efficiently intercalate among aromatic rings, and their interfacial distribution can be tuned via molecular engineering. The polymersomes can be programmed in a Boolean logic‑gate manner (OR, AND, and NOT) to synthesize skin‐mimetic gels with tailored mechanical properties, analogous to fibroblast behavior. Furthermore, the platform enables on‑demand, high‑resolution 3D printing of complex bioskin architectures. This work provides a biomimetic paradigm for the synthesis and precise control over assembly from the molecular to the macroscopic scale.

Ageing is inevitable and accompanied by progressive loss of skin elasticity. Fibroblasts, embedded within the extracellular matrix, finely regulate skin mechanics via membrane‐bound ligands. Creating synthetic assemblies that mimic fibroblast function is appealing yet challenging. Here, we present a strategy that co‐assembles lignin with divinyl ligands to generate fibroblast‐mimicking polymersomes, enabling precise programming of bulk materials to emulate human skin across distinct physiological stages. Because lignin polymersomes are driven by relatively weak π–π stacking, hydrophobic ligands efficiently intercalate among aromatic rings, and their interfacial distribution can be tuned via molecular engineering. The polymersomes can be programmed in a Boolean logic‑gate manner (OR, AND, and NOT) to synthesize skin‐mimetic gels with tailored mechanical properties, analogous to fibroblast behavior. Furthermore, the platform enables on‑demand, high‑resolution 3D printing of complex bioskin architectures. This work provides a biomimetic paradigm for the synthesis and precise control over assembly from the molecular to the macroscopic scale.

The balance between excitatory and inhibitory (E/I) signaling underpins complex neural functions in biological systems. However, replicating such ion‐mediated regulation with biobased materials in artificial systems remains challenging. Herein, we demonstrate two distinct light‐modulated 2D nanofluidic memristors based on paper‐mill waste (xylan) reinforced membranes that emulate complementary E/I synaptic signaling, enabling precise robotic motion control via ionic neural networks. The memristors were constructed using xylan‐reinforced MXene membranes with asymmetric electrolytes, leveraging the interfacial interactions between the functional groups of xylan derivatives and MXene to achieve nanofluidic membrane assembly and precise control over surface charge and ion selectivity. Upon illumination, the photothermal effect of MXene induces a uniform thermal field that enables thermally activated ion transport in the interlayer spacing, allowing these biomass‐based memristors to emulate key excitatory and inhibitory synaptic behaviors. These complementary memristors further implement reconfigurable Boolean logic operations and serve as foundational components for ionic circuits, as demonstrated in series and parallel configurations. As a proof‐of‐concept, an E/I‐integrated ionic neural network achieved precise control of ten robotic motion modes by tuning light pulses, concentration gradients, and ion selectivity. This work highlights the potential of biomass‐reinforced materials for nanofluidic memristors and explores new frontiers in the application of biomass materials.

The microscopic state of polysaccharides in solution─whether dissolved, dispersed, or aggregated─directly dictates the macroscopic properties of the bulk fluid. However, the influence of their true state in solution and nanostructures on rheology is often overlooked. Here, using non-Newtonian shear-thickening fluids (STFs, SiO₂/poly(ethylene oxide)) as a model, we systematically investigate how xylan conformation and dispersion affect STFs' rheology. Xylan nanocrystals (XNCs) and water-soluble xylan ethers with distinct dispersibility (well-dispersed vs aggregate) and solubility (room-temperature-soluble vs high-temperature-soluble) are synthesized. Among those, well-dispersed XNCs and room-temperature-soluble xylan ethers exhibit a pronounced thickening effect in STFs, reducing the critical shear rate by 2 orders of magnitude and increasing peak viscosity by 880%. This work demonstrates that polysaccharide conformation and dispersion behavior exert pronounced effects on STF rheology, providing a new avenue for leveraging polysaccharides as fluid additives.

One-pot xylan-derived photoluminescent vitrimers enable high-resolution DLP 3D printing, thermal reprocessing, upcycling, and programmable water-triggered degradation.

Trees, consisting of leaves, trunks, etc., efficiently eliminate gaseous pollutants and serve as an indispensable air purification system for Earth. In this study, lignin from trunks and phytol from leaves are co‐assembled into macroporous nanospheres with high purification efficiency for scavenging gaseous reactive oxygen species (ROS) and harmful gases, which are integrated into cigarette filters for lung protection. The alkyl chains of phytol disrupt the π–π stacking in lignin, forming pore throats that expand from 0 to 120 nm as phytol content increases. Consequently, the higher levels of anchored phytol, the greater the antioxidant capacity of the co‐assemblies. The macroporous nanospheres are subsequently loaded into cigarette filters, with each gram of porous nano‐lignin capable of treating ≈100 standard cigarettes. The gaseous ROS scavenging efficiency can reach up to 97%, effectively removing harmful gases like carbon monoxide and formaldehyde, outperforming existing cigarette filters. In a mouse model, cigarette filters containing these microscopic air purifiers significantly suppressed inflammation and provided notable lung tissue protection. This study presents a robust non‐covalent method that is both straightforward and efficient, enabling the rapid application of plant extracts in highly effective and sustainable filter materials.

This review focuses on advances in bioplastics built on a d -xylose core, and points the way for their current challenges and future opportunities.