International Journal of Biological Macromolecules最新文献

Conventional enzyme immobilisation often relies on chemical crosslinkers that can compromise biocompatibility and activity. This study introduces a crosslinker-free strategy for biomaterial functionalisation that exploits the reversible self-aggregation of the p40 domain from Caldibacillus cellulovorans. Inclusion bodies of p40-fusion proteins were solubilised with guanidinium hydrochloride and reaggregated onto diverse matrices, including polypropylene fibres, cellulose fabrics, and porous beads, forming stable enzyme-functionalised surfaces under mild aqueous conditions. Fluorescent mCherry_p40 fusions confirmed uniform reaggregation and matrix attachment, demonstrating the versatility of the approach across material types. The method achieved functionalisation efficiencies of 82-100%, while catalytically active p40-enzyme inclusion bodies retained 75-100% of their initial activity following matrix functionalisation. α-Amylase_p40-functionalised polypropylene fibres maintained full catalytic activity for twelve reaction cycles at 70 °C and approximately 50% at 80 °C, while tagatose 4-epimerase_p40-functionalised matrices demonstrated proof-of-concept applicability in a SpinChem® rotating bed reactor, supporting D-tagatose formation over ten cycles. Fourier transform infrared analyses indicated β-sheet-rich secondary structures consistent with ordered, functional aggregates. These findings show that β-sheet-mediated, reversible aggregation of p40 inclusion bodies provides a robust, scalable, and sustainable route for producing highly stable enzyme-matrix assemblies, offering a general platform for industrial biocatalysis and other biofunctional material applications.

Wound dressing materials that possess injectability, tissue adhesion, and self-healing abilities, with the added advantage of therapeutic potential, are highly desired in medicine. This research used quaternized chitosan incorporating gallic acid (QCS-GA), prepared by a so-called grafting method, which resulted in GA incorporation mainly through ionic interactions, as evidenced by detailed chemical characterization, including 2D DOSY NMR and XPS. QCS-GA, in combination with oxidized pectin (OPEC), was used to synthesize hydrogels with three different GA contents. These hydrogels were cross-linked by dynamic reversible covalent bonds and ionic bonds between QCS-GA and OPEC, providing the hydrogels with injectable, adhesiveness, self-healing properties, and gel fractions from 88 to 97%. Despite the lack of grafting, the pretreatment of QCS and GA with hydrogen peroxide and ascorbic acid resulted in superior hydrogel properties that could not be reproduced using physical mixtures of QCS and GA. An increase in GA content in the hydrogels decreased the gelation time, reduced the degradation rate, and enhanced in vitro antioxidant activity. The hydrogel with the highest GA content displayed broad-spectrum in vitro antibacterial ability due to the intrinsic antibacterial properties of GA and QCS, as well as excellent in vitro cytocompatibility and cell migration. Therefore, this hydrogel can be a multifunctional injectable self-healing hydrogel with potential as a wound dressing.

Traditional agrochemicals suffer from low utilization rates and high environmental exposure levels, posing threats to ecosystem security and limiting their practical application. Wheat stem rot is one of the world's major agricultural diseases caused by Fusarium pseudograminearum, which mainly affects the stem base of wheat. Improving the agent's deposition distribution and duration of action in the wheat rhizome is critical when applied through foliar spray or root application.to control this disease. Stimuli-responsive delivery systems can provide more effective crop protection while improving the safety of pesticides for non-target organisms and the environment. In this study, we developed pectin-modified pyraclostrobin nanocapsules (NCS@Pec) exhibiting dual responsiveness to pH and pectinase. Compared to conventional nanoemulsion (NEW), NCS@Pec demonstrated superior adhesion to wheat surfaces with 2.86-fold enhanced rainfastness. Root application reduced pyraclostrobin translocation to leaves while prolonging rhizosphere activity. At 14 days post-treatment, NCS@Pec maintained approximately 68% control efficacy. In addition, the selectivity coefficients of NCS@Pec between F. pseudograminearum and zebrafish were 2.67 and 7.09, significantly reducing environmental risks to aquatic life while maintaining fungicidal activity. These findings advance the application of carbohydrate polymers such as pectin in nanopesticide development and contribute to novel bioactive agent design and food security enhancement.

Conductive hydrogels have garnered significant attention in the field of flexible wearable sensors due to their intrinsic conductivity and tunable mechanical properties. However, simultaneously achieving both high mechanical stability and high sensing sensitivity remains a significant challenge. In this study, a conductive hydrogel with a low-hysteresis interpenetrating polymer network structure was fabricated via one-pot free-radical polymerization. The three-dimensional network of bacterial cellulose (BC) provides mechanical support for MXene, forming the first network layer of the hydrogel via hydrogen bonding. The second network is constructed by in situ polymerization of acrylamide (AM) within the BC framework. The incorporation of BC significantly improves both mechanical strength and electrical conductivity, effectively overcoming the typical trade-off among strength, toughness, and conductivity observed in conventional conductive hydrogels. As a result, the optimized hydrogel exhibits exceptional stretchability (elongation at break ~1800%), high toughness, excellent resilience, and high conductivity (435.6 mS m^-1), along with a rapid response time of 400 ms. Moreover, the hydrogel demonstrates high sensing sensitivity (GF = 11.48 at 600-800% strain) and long-term signal stability, enabling its application in flexible wearable sensors for accurate detection of human motion and voice signals. These properties highlight the hydrogel's broad potential for use in human-machine interface technologies.

Alginate-based hydrogels, nanoparticles, and composite delivery systems have emerged as adaptable platforms for cancer therapy when their efficacy is led by rational management of polymer structure and modification technique, according to recent research conducted between 2020 and 2025. To customize drug loading capacity, release kinetics, tumor-responsive behavior, and biological activity, this review focuses exclusively on the intentional tuning of alginate block composition (M/G ratio and block distribution), molecular weight, and physical, chemical, or biological modifications. The review critically investigates the structure-property-function linkages that control therapeutic results across localized and systemic delivery platforms, as opposed to offering a solely descriptive summary of formulation types. The development of multifunctional systems that combine chemotherapy with photothermal, antiangiogenic, or immunomodulatory effects while reducing off-target toxicity, improved solubility and stability of hydrophobic anticancer agents, and pH- and redox-responsive drug release in tumor-like microenvironments are all discussed in relation to alginate-based carriers. Across recent studies, alginate-based carriers consistently achieve high drug encapsulation efficiencies (typically 60-95%), pH- or stimulus-responsive release with up to 65-90% drug liberation under tumor-like conditions and marked biological gains, including 2-12-fold reductions in IC₅₀ values compared to free drugs. These improvements are mechanistically associated with enhanced apoptotic signaling (e.g., Bax, p53, caspase-3/9 activation) and suppression of proliferative and metastatic pathways, underscoring the functional advantages of rational alginate design. Beyond identifying critical limitations, this review frames batch variability, long-term safety, and translational barriers through a structure-property-performance lens, highlighting design parameters and evaluation strategies that support reproducibility, scalability, and regulatory readiness. By integrating comparative metrics and mechanistic insights, the review guides rational optimization of alginate-based systems to accelerate their progression toward clinical application.

Residues of tetracycline antibiotics (TCs) in aquaculture pose serious risks to environmental and human health. Although laccase-based enzymatic degradation offers a green and sustainable strategy for removing TCs from marine aquaculture wastewater, its application is often hindered by inefficient enzyme production and stability issues. In this study, we engineered Aspergillus oryzae, a Generally Recognized as Safe (GRAS) filamentous fungus with powerful secretory capabilities, for the homologous overexpression of laccase. After purification, the laccase was stably immobilized onto polycarboxylate-functionalized magnetic nanoparticles via covalent bonding. Compared with free laccase, the immobilized enzyme exhibited markedly enhanced performance under various conditions, including pH tolerance, thermostability, long-term storage stability, and reusability. This novel biocatalyst, exhibiting optimal activity under neutral to slightly alkaline conditions, was subsequently applied to degrade TCs in simulated aquaculture wastewater. The maximum removal efficiencies of tetracycline (TC) and oxytetracycline (OTC) (10 mg/L) by the immobilized laccase reached 82.9% and 87.84%, respectively. Based on the identification of intermediates, the pathways for TC removal involve dehydrogenation, demethylation, and ring-opening reactions, resulting in less toxic and readily biodegradable products. Overall, this system demonstrates strong potential for effective removal of TCs from aquaculture wastewater and for broader environmental remediation applications.

HIV-1 multidrug resistance remains a major barrier to effective long-term antiretroviral therapy and highlights the need for robust biochemical models for screening next-generation inhibitors. Reverse transcriptase (RT) is a central therapeutic target whose inhibition is compromised by the accumulation of resistance mutations that alter substrate usage and reduce drug susceptibility. Here, we engineered, purified, and functionally characterized a recombinant HIV-1 RT variant carrying twelve clinically relevant resistance-associated mutations (12MRT) representative of highly treatment-experienced patient genotypes. The 12MRT enzyme was expressed in E. coli and purified to >95% homogeneity. Kinetic analysis revealed reduced catalytic efficiency, with a 2.1- to 2.6-fold increase in K_m and a 30-40% reduction in V_max relative to wild-type RT (wtRT). In drug susceptibility assays, 12MRT exhibited markedly increased IC50 values for first-generation NNRTIs (8- to 15-fold) and moderate resistance to NRTIs (4- to 7-fold), while retaining measurable polymerase activity suitable for quantitative inhibition studies. Structural analysis suggests that mutation clustering perturbs inhibitor binding without disrupting global folding. Together, these findings demonstrate that 12MRT authentically reproduces multidrug-resistant RT phenotypes and provides a scalable, mechanistically informative platform for preclinical antiviral screening and evaluation of next-generation therapeutic candidates.