International Journal of Biological Macromolecules最新文献

Photodegradation is an important factor that affects the terrestrial carbon cycle. Lignin is a main component of plant biomass, easily and selectively undergoes photodegradation. Moreover, lignin provides key information that is essential for studying photodegradation of plant biomass. Enzymatic hydrolysis lignin (EHL) was used in a novel investigation of photodegradation of plant biomass in the presence of various quantities of sprayed water. The EHL specimen without sprayed water exhibited obvious photooxidation, cleavage and depolymerization under ultraviolet radiation; its C and H contents declined; its residue yield increased by 1.00 %; and its O/C ratio, C4, and O2 growth rates based on X-Ray photoelectron spectroscopy increased by 15.15 %, 27.11 %, and 132.09 %, respectively. Water has been shown to play an important role in lignin photodegradation, with a moderate amount resulting in the highest oxidation degree. Importantly, photodegradation of lignin accelerates the return of fixated carbon to the atmosphere. EHL sprayed 0.46 g g^-1 water exhibited an obvious decrease in C (-2.64 %), C1s (-6.89 %), C1 (-12.53 %), and C2 (-19.92 %) content after 320 h of UV exposure. This study provides a new perspective to further understand the effects of plant biomass photodegradation on terrestrial carbon cycling.

Lignocellulosic waste is a prevalent byproduct of agricultural and forestry activities which is an excellent feedstock for the preparation of biochar. This research area is of interest to the scientific community due to its potential in environmental remediation. In this regard, this review examines the latest advancements in transforming lignocellulosic waste into biochar and explores recent innovations in enhancing its functionality for chromium ion removal. It gives analysis on current methods for biochar production from lignocellulosic materials such as pyrolysis. Additionally focusing on improvements in production efficiency, structural properties, and surface modifications. The review also highlights various functionalization techniques, such as chemical activation and impregnation with metal oxides, that were innovated to improve adsorptive nature of biochar for chromium ions. While progress has been made, achieving scalability in lignocellulosic biochar production presents challenges, such as the high energy demands of pyrolysis, inconsistencies in feedstock quality, and the need for cost-effective functionalization methods. By summarizing recent research and technological progress, this paper aims to offer a clear perspective on the effectiveness of biochar derived from lignocellulosic waste in addressing contamination. Additionally, it discusses the ongoing challenges and future research directions needed to optimize biochar applications in environmental cleanup.

This study demonstrates the development of stimuli-responsive Pickering emulsions stabilized by casein nanoparticles (CNPs) for targeted drug delivery to colorectal cancer cells (CRC). Encapsulation of a fluorescent dye simulates therapeutic delivery, demonstrating biomedical potential. The oil-in-water nanoemulsions stabilized by CNPs function as nanocarriers sensitive to matrix metalloproteinase-7 (MMP-7), an enzyme overexpressed in CRC cells, enabling precise drug release. Emulsions exhibited strong stability due CNPs forming a robust layer at the oil-water interface, enhancing bioavailability and controlled release. Covalent modifications of CNPs with polyethyleneimine (PEI) or polyacrylic acid (PAA), and pH adjustments optimize the zeta potential, improving surface charge and delivery efficiency. Maximal CNP uptake occurred with PAA-modified CNPs (-20 mV), showing superior interaction with CRC cells compared to pristine (-6.7 mV) and PEI-modified (+30.5, +42.1 mV) CNPs. Confocal microscopy and imaging flow cytometry confirmed that CNP-stabilized emulsions enhance CRC inter-localization compared to dispersed CNPs. Nanoemulsions with the highest CNP uptake showed selective interaction with tumor cells, while minimizing oil droplet uptake, driven by nanoscale dimensions and targeted surface interactions. Enzymatic degradation of CNPs by MMP-7 induces phase separation and targeted release. This dual-functional system, leveraging charge modification and enzymatic responsiveness, highlights CNP-stabilized nanoemulsions as a promising CRC-targeted drug delivery platform.

Apostichopus japonicus is one of the most popular types of sea cucumber among consumers in Southeast Asia. Fucoidan from Apostichopus japonicus (Aj-FUC) has attracted considerable attention because of its immunomodulatory activities. Aj-FUC is indigestible in the human upper gastrointestinal tract but can be utilized by the gut microbiota. Thus, we suspect that Aj-FUC interacts with the gut to enhance immunefunction. This study showed that after a three-week intervention with Aj-FUC (100 mg/kg/d), the gut microbiota in mice developed a new homeostasis. Subsequently, in the condition of intestinal flora homeostasis, the effects of Aj-FUC on intestinal health in normal mice and the prevention of intestinal mucosal damage in cyclophosphamide-induced mice were investigated. Aj-FUC preserved intestinal structural integrity, increased the number of goblet cells, upregulated the expression of ZO-1 and Occludin, stimulated the secretion of sIgA and IgA, and maintained the Th1/Th2 balance. Importantly, beneficial bacteria were enriched, and tryptophan metabolism-related metabolites such as 5-hydroxyindole-3-acetic acid, and indole-3-lactic acid were upregulated following Aj-FUC administration. In summary, a three-week Aj-FUC intervention could result in the formation of a new homeostasis in intestinal flora, while the effect of Aj-FUC on intestinal immunity was related to the regulation of tryptophan metabolism by gut microbiota.

A new acidic polysaccharide was extracted from Lespedeza Formosa (LF) using microwave-assisted extraction. After a progressive purification, Lespedeza Formosa polysaccharide (LFP-1) with 96.14 % purity and moderate molecular weight was obtained. Subsequently, LFP-1's structural analysis and in vitro anti-inflammatory experiments were performed. LFP-1 is composed of nine monosaccharides, mainly including 39.7 % glucose, 29.1 % galactose, and 19.9 % arabinose, with three branched chains of its structure. The diverse monosaccharides and branched chains provided the essential conditions for the anti-inflammatory effects of LFP-1, which diminished the release of nitric oxide (NO) and reactive oxygen species (ROS). And they altered the release of internal inflammatory factors in lipopolysaccharide (LPS)-treated macrophages. LFP-1 exerted intracellularly anti-inflammatory effects through the nuclear factor kappa-B (NF-κB) signal pathway. The discovery of LFP-1 opens up a new possibility for natural anti-inflammatory medicine.

Hemoglobin, composed of α- and β-chains, is essential for oxygen transport and is key in diagnosing and treating gastrointestinal and blood disorders. It also aids in detecting blood contamination and estimating transfusion volumes. Immunological methods, based on antigen-antibody interactions, are distinguished by their high sensitivity and accuracy. Consequently, it is necessary to develop hemoglobin-specific antibodies characterized by high specificity and affinity to enhance detection accuracy. The variable domain of the new antigen receptor (VNAR) from sharks, the smallest antigen-binding unit, is ideal for disease diagnosis and treatment due to its small size, stability, and high affinity. In this study, Chiloscyllium plagiosum was immunized with human hemoglobin protein. Nine VNAR immune libraries with sizes ranging from 1 × 10⁸ to 1.82 × 10⁹ colony-forming units (CFU) were constructed and biopanned using phage display, resulting in three hemoglobin-specific VNAR sequences (5-10C, 7-11A, T-12-4D). These sequences were inserted into pTT5-TEV-Fc vectors and transfected into HEK 293F cells. The resulting VNAR-Fc fusion proteins were purified from the cell culture supernatants. Binding activity, cross-reactivity, physicochemical stability, and epitope competition were evaluated using non-competitive enzyme-linked immunosorbent assay (ELISA) and biolayer interferometry (BLI). T-12-4D-Fc exhibited the highest affinity with a K_D value of 7.59 nM and superior physicochemical stability. It maintained over 80 % binding activity at 90 °C, over 51 % in extreme pH conditions (pH 2 and 12), and above 65 % in urea concentrations up to 8 mol/L. Its binding activity remained largely unaffected after 6 h of incubation in human plasma-like medium (HPLM). The binding epitope competition results showed that 5-10C-Fc and T-12-4D-Fc targeted the same hemoglobin epitope. Molecular dynamics simulations revealed hydrogen bonds as the primary interaction force between VNARs and hemoglobin. Furthermore, a double-antibody sandwich enzyme-linked immunosorbent assay (DAS-ELISA) method was established for the detection of human hemoglobin, utilizing T-12-4D-Fc as the coating antibody. This technique demonstrated high accuracy, reproducibility and specificity when applied to human whole blood samples. Hence, the identified VNARs, particularly T-12-4D, demonstrated good stability, specificity, and high affinity, filling the gap of hemoglobin-targeting shark-derived single-domain antibodies and offering a foundation for diagnosing and monitoring hemoglobin-related diseases.

Post-traumatic osteoarthritis remains a significant clinical challenge, with limited effective treatment options. Conventional hydrogels for articular cartilage repair primarily focus on the bioactivity of the materials but often overlook the importance of monitoring the hydrogel's behavior in situ. This study presents the development of a novel injectable, traceable fluorescent hydrogel designed to prevent cartilage degradation and promote cartilage regeneration. The hydrogel was synthesized by forming a dynamically crosslinked network of oxidized hyaluronic acid (OHA) and adipic dihydrazide-grafted HA (HA-ADH), followed by photo-crosslinking with methacrylated gelatin (GelMA). Furthermore, GelMA was covalently conjugated with Rhodamine B, enabling real-time tracking of hydrogel degradation in situ. Experimental results demonstrated that the fluorescence of the hydrogel could effectively penetrate both skin and cartilage tissues, allowing for real-time monitoring. Additionally, the hydrogel exhibited superior lubrication (with a coefficient of friction of 0.134, comparable to HA) and favorable rheological properties, along with excellent biocompatibility. It also promoted cell differentiation and migration. In vivo studies showed that the hydrogel facilitated cartilage repair and prevented cartilage degradation over a 56-day period. Given its mechanical properties, biocompatibility, and fluorescence-based monitoring capability, this hydrogel shows great promise for real-time tracking in cartilage repair for the treatment of post-traumatic osteoarthritis.

Rod-like chitin nanocrystals (ChNCs) filled biodegradable aliphatic polyesters are of great interest because as-obtained nanocomposites are all-degradable. In this work, we prepared a poly(ε-caprolactone-b-l-lactide) (PCL-b-PLA) copolyester nanocomposite with ChNCs and carried out a crystallization study. The results disclosed that the roles of ChNCs played during crystallization of copolyester matrices were very attractive: as heterogeneous nucleator of PLA phase, whereas as inert filler for PCL phase. Thus, the overall crystallization kinetics of PLA phase were accelerated. The heterogeneous nucleation led to the formation of more amounts of crystallized PLA domains, which favored nucleating following crystallization of PCL phase. In addition, the presence of ChNCs did not strongly influence the microphase-segregated structure of PCL-b-PLA, and had good reinforcements to matrix copolymer. The selective nucleation ability of ChNCs reported in this study is valuable for regulating the structures and properties of nanocomposites based on the ChNCs-filled aliphatic diblock copolyester with double crystalline blocks.

Polyelectrolyte multilayers (PEMs) based on hyaluronic acid (HA) and poly (diallyldimethylammonium chloride) (PDDA) were deposited on oxidized polystyrene (PS_ox) via the layer-by-layer (LbL) method. The X-ray photoelectron spectroscopy (XPS) confirmed the PEM deposition on PS_ox, and atomic force microscopy (AFM) indicated that the surface roughness of PS also increased after PEM deposition. The PEMs significantly enhanced PS wettability, reducing the contact angle from 73° on PS to 24° on PDDA-terminated (PDDA/HA)_2.5 PEM (2.5 bilayers, 5 layers) and 36° on HA-terminated (PDDA/HA)₃ PEM (3 bilayers, 6 layers). The HA-terminated (PDDA/HA)₃ PEM demonstrated antimicrobial activity. Compared to uncoated PS surfaces, this PEM reduced the surface coverage of viable P. aeruginosa cells from 36.5 % to 3.7 % and S. aureus cells from 13.3 % to 2.5 % on uncoated PS surfaces. The antimicrobial assay following the JIS Z 2801-2010 standard demonstrated that the PDDA-terminated (PDDA/HA)_2.5 PEM inhibited S. aureus growth by 48 %, compared to 32 % inhibition by the HA-terminated (PDDA/HA)₃ PEM relative to the uncoated and non-oxidized polystyrene (PS) surface (control). HA-terminated PEM demonstrated lesser antimicrobial activity than PDDA-terminated PEM. However, both PEMs were cytocompatible against erythrocytes and human adipose-derived stem cells (ADSCs), indicating their potential for biomedical applications, particularly prosthetic coatings.