Carbohydrate Polymers最新文献

Injectable hydrogels with heterogeneous fibrous structures possessing good mechanical and biological characteristics are attracting increasing research interest in cartilage repair. The integration of nanofibers into hydrogel would largely enhance mechanical property, but impedes the gelation process and formation of hydrogel structures. Construction of biocompatible and mechanical supporting hydrogel with low fiber content remains a challenge. In this study, we developed a chemical cross-linked fibrous hydrogel, namely Thiol chitosan-Poly (lactic-co-glycolic acid)-Polydopamine (CSSH-PP), for facilitating cell proliferation and promoting cartilage tissues regeneration. Compared to conventional CSSH hydrogels, the compressive strength of CSSH-PP scaffolds exhibited a significant increase percentage of 100 %. Incorporation of CSSH-PP upgraded the cell migration with a four-fold increase. Besides, the infiltration of host cells and the formation of new blood vessels were observed in rat models when implanted with CSSH-PP, enhancing the native tissue microenvironmental reconstruction and leading a sustained repair in articular cartilage.

Lightweight, energy-efficient materials in building construction typically include polymeric and composite foams. However, these materials pose significant fire hazards due to their high combustibility and toxic gas emissions, including carbon monoxide and hydrogen cyanide. This study delves into the latter aspects by comparing hybrid systems based on nanofiber-reinforced silica-based Pickering foams with a synthetic reference (polyurethane foams). The extent and dynamics of fire retardancy and toxic gas evolution were assessed, and the results revealed the benefits of combining the thermal insulation of silica with the structural strength of biobased nanofibers, the latter of which included anionic and phosphorylated cellulose as well as chitin nanofibers. We demonstrate that the nanofiber-reinforced silica-based Pickering foams are thermal insulative and provide both fire safety and energy efficiency. The results set the basis for the practical design of hybrid foams to advance environmental sustainability goals by reducing energy consumption in built environments.

Tumor vaccines have become a promising approach for cancer treatment by triggering antigen-specific responses against tumors. However, autophagy and immunosuppressive tumor microenvironment (TME) reduce antigen exposure and immunogenicity, which limit the effect of tumor vaccines. Here, we develop fucoidan (Fuc) based chlorin e6 (Ce6)-chloroquine (CQ) self-assembly hydrogels (CCFG) as in situ vaccines. Ce6 triggers immune response in situ by photodynamic therapy (PDT) induced immunogenic cell death (ICD) effect, which is further enhanced by macrophage polarization of Fuc and autophagy inhibition of CQ. In vivo studies show that CCFG effectively enhances antigen presentation under laser irradiation, which induces a powerful in situ vaccine effect and significantly inhibits tumor metastasis and recurrence. Our study provides a novel approach for enhancing tumor immunotherapy and inhibiting tumor recurrence and metastasis.

Uncontrolled non-compressible hemorrhage, which is often accompanied by coagulopathy, is a major cause of mortality following traumatic injuries in civilian and military populations. In this study, coagulopathy-independent injectable catechol-modified chitosan (CS-HCA) hemostatic materials featuring rapid shape recovery were fabricated by combining controlled sodium tripolyphosphate-crosslinking with hydrocaffeic acid (HCA) grafting. CS-HCA exhibited robust mechanical strength and rapid blood-triggered shape recovery. Furthermore, CS-HCA demonstrated superior blood-clotting ability, enhanced blood cell adhesion and activation, and greater protein adsorption than commercial hemostatic gauze and Celox. CS-HCA showed enhanced procoagulant and hemostatic capacities in a lethal liver-perforation wound model in rabbits, particularly in heparinized rabbits. CS-HCA is suitable for mass manufacturing and shows promise as a clinically translatable hemostat.

Cellulose nanofibril (CNF) films with both high strength and high toughness are attractive for applications in energy, packaging, and flexible electronics. However, simultaneously achieving these mechanical properties remains a significant challenge. Herein, a multiscale structural optimization strategy is proposed to prepare high aspect ratio CNFs with reduced crystallinity for strong and tough films. Carboxymethylation coupled with mild mechanical disintegration is employed to modulate the multiscale structure of CNFs. The as-prepared CNFs feature an aspect ratio of >800 and a crystallinity of <60 %. The film prepared using CNFs with a high aspect ratio (~1100) and reduced crystallinity (~54 %) exhibits a tensile strength of 229.9 ± 9.9 MPa and toughness of 22.2 ± 1.4 MJ/m³. The underlying mechanism for balancing these mechanical properties is unveiled. The high aspect ratio of the CNFs facilitates the transfer and distribution of local stress, thus endowing the corresponding film with high strength and toughness. Moreover, the low crystallinity of the CNFs permits the movement of the cellulose chains in the amorphous regions, thereby dissipating energy and finally increasing the film toughness. This work introduces an innovative and straightforward method for producing strong and tough CNF films, paving the way for their broader applications.

Accurate evaluation of electrophysiological and morphological characteristics of the skeletal muscles is critical to establish a comprehensive assessment of the human neuromusculoskeletal function in vivo. However, current technological challenges lie in unsynchronized and unparallel operation of separate acquisition systems such as surface electromyography (sEMG) and ultrasonography. Key problem is the lack of ultrasound transparency of current electrophysiological electrodes. In this work, ultrasound (US) transparent electrode based on cellulose nanofibrils (CNF) substrate are proposed to solve the issue. US transparency of the electrodes are evaluated using a standard US phantom. The effects of nanocellulose type and ion-bond introduction on electrode performance is investigated. Simultaneous US image and sEMG signal acquisition of biceps brachii during isometric muscle contraction are studied. Reliable correlation analysis of the US and sEMG signals is realized which is rarely reported in the previous literatures. Recyclability and biodegradability of the current electrode are evaluated. The reported technology opens up new pathways to provide coupled anatomical and electrical information of the skeletal muscles, enables reliable anatomical and electrical information correlation analysis and largely simplify the sensor integration for assessment of the human neuromusculoskeletal function.

Melanoma either intrinsically possesses resistance or rapidly acquires resistance to anti-tumor therapy, which often leads to local recurrence or distant metastasis after resection. In this study, we found histone 3 lysine 27 (H3K27) demethylated by an inhibitor of histone methyltransferase EZH2 could epigenetically reverse the resistance to chemo-drug paclitaxel (PTX), or enhance the efficacy of immune checkpoint inhibitor anti-TIGIT via downregulating TIGIT ligand CD155. Next, to address the complexity in the combination of multiple bioactive molecules with distinct therapeutic properties, we developed a polysaccharides-based organohydrogel (OHG) configured with a heterogenous network. Therein, hydroxypropyl chitosan (HPC)-stabilized emulsions for hydrophobic drug entrapment were crosslinked with oxidized dextran (Odex) to form a hydrophilic gel matrix to facilitate antibody accommodation, which demonstrated a tunable sustained release profile by optimizing emulsion/gel volume ratios. As results, local injection of OHG loaded with EZH2 inhibitor UNC1999, PTX and anti-TIGIT did not only synergistically enhance the cytotoxicity of PTX, but also reprogrammed the immune resistance via bi-directionally blocking TIGIT/CD155 axis, leading to the recruitment of cytotoxic effector cells into tumor and conferring a systemic immune memory to prevent lung metastasis. Hence, this polysaccharides-based OHG represents a potential in-situ epigenetic-, chemo- and immunotherapy platform to treat unresectable metastatic melanoma.

Applying conductive hydrogels in electronic skin, health monitoring, and wearable devices has aroused great research interest. Yet, it remains a significant challenge to prepare conductive hydrogels simultaneously with superior mechanical, self-recovery, and conductivity performance. Herein, a dual ionically cross-linked double network (DN) hydrogel is fabricated based on K⁺ and Fe³⁺ ion cross-linked κ-carrageenan (κ-CG) and Fe³⁺ ion cross-linked poly(sodium acrylate-co-acrylamide) P(AANa-co-AM). Benefiting from the abundance of hydrogen bonds and metal coordination bonds, the conductive hydrogel has excellent mechanical properties (fracture strain up to 1420 %, fracture stress up to 2.30 MPa, and toughness up to 20.63 MJ/m³) and good self-recovery performance (the recovery rate of the toughness can reach 85 % after waiting for 1 h). Meanwhile, due to the introduction of dual metal ions of K⁺ and Fe³⁺, the ionic conductivity of conductive hydrogel is up to 1.42 S/m. Furthermore, the hydrogel strain sensor has good sensitivity with a gauge factor (GF) of 2.41 (0–100 %). It can be a wearable sensor that monitors different human motions, such as sit-ups. This work offers a new synergistic strategy for designing a hydrogel strain sensor with high mechanical, self-recovery, and conductive properties.

Molecular weight (Mw) of ligand-mediated nanocarriers plays a pivotal role in their architecture and properties. In this study, self-assembled ovalbumin (OVA)-loaded nanoparticles were meticulously engineered by starch polyelectrolytes with different Mw. Results unveiled that, tailoring Mw of GRGDS pentapeptides-grafted carboxymethyl starch (G-CMS) displayed strong binding-affinity and transport efficiency through microfold cells (M cells) pathway in the simulated intestinal epithelial cell monolayer in which M cells were randomly located in the Caco-2 cells monolayer. Notably, nanoparticles assembled from G-CMS with relatively higher Mw exhibited more compact structures due to the stronger interactions between layers compared to that with relatively lower Mw, which rendered remarkably stable and only 19.01 % in vitro OVA leakage under conditions of the upper gastrointestinal tract. Subsequently, more intact nanoparticles reached M cells after in vitro digestion and exhibited higher transport efficiency through the M cells pathways (apparent permeability: 9.38 × 10⁻⁵ cm/s) than Caco-2 cells, attributing to specific- and non-specific binding affinity towards M cells. Therefore, optimal Mw tailoring of starch polyelectrolytes can mediate the molecular interactions among their assembled layers and the interactions with M cells to balance the structural compactness, release and transport efficacy of nanoparticles, holding promise for advancing M cells-targeting oral delivery technologies.

This review article explores the developments and applications in agar-based composites (ABCs), emphasizing various constituents such as metals, clay/ceramic, graphene, and polymers across diversified fields like wastewater treatment, drug delivery, food packaging, the energy sector, biomedical engineering, bioplastics, agriculture, and cosmetics. The focus is on agar as a sustainable and versatile biodegradable polysaccharide, highlighting research that has advanced the technology of ABCs. A bibliometric analysis is conducted using the Web of Science database, covering publications from January 2020 to March 2024, processed through VOSviewer Software Version 1.6.2. This analysis assesses evolving trends and scopes in the literature, visualizing co-words and themes that underscore the growing importance and potential of ABCs in various applications. This review paper contributes by showcasing the existing state-of-the-art knowledge and motivating further development in this promising field.