The rapid release of conventional urea fertilizers results in low nutrient utilization efficiency and environmental contamination, highlighting the need for sustainable controlled-release systems. Herein, an agar-based dual-barrier hydrogel fertilizer (ACCMPU) was developed by incorporating polydopamine-modified urea-loaded mesoporous silica nanoparticles (MSNs@PDA-Urea) into a CNCs/CMC-Na-reinforced agar network. The PDA coating and polysaccharide matrix constructed hierarchical diffusion barriers to regulate urea transport at nanoscale and macroscopic levels. The incorporation of CNCs and CMC-Na enhanced the mechanical robustness of the hydrogel, increasing the compressive strength from 0.15 MPa to 0.33 MPa and elastic modulus from 1.15 MPa to 2.75 MPa. Compared with free urea released within 4 h, ACCMPU exhibited sustained nutrient delivery with only 92.56% cumulative urea release after 360 h. The effective diffusion coefficient decreased to 2.41 × 10−12 m2 s−1, confirming the enhanced diffusion resistance of the dual-barrier structure. Moreover, ACCMPU maintained structural stability during soil degradation and promoted lettuce growth, increasing fresh and dry weights to 171.0 mg and 16.4 mg after 10 days of cultivation. This study provides a promising strategy for designing novel hydrogel slow-release fertilizers by integrating nanoscale encapsulation with agar-based hydrogel networks. Further field studies are required to evaluate long-term agricultural performance and practical scalability.
This study evaluated the simultaneous effect of processing temperature (95, 120, and 140 °C), α-amylase-mediated hydrolysis (0–75% peak viscosity reduction), and 72 h storage on the structure and functionality of pea starch. Pasting properties and gel hardness were significantly affected by all factors, with peak viscosity decreasing from 2924 to 682 cP and setback approaching zero at high hydrolysis levels. Gel hardness showed a non-linear response: low hydrolysis enhanced gel strength at 120 °C (1725 ± 31 g), whereas extensive hydrolysis consistently weakened gel formation. Storage promoted retrogradation, increasing gel hardness up to 3126 ± 21 g and enhancing thermal stability in selected systems. RS content varied between 11.08 and 21.63 g/100 g, with the highest values observed at 95 °C under mild hydrolysis, while excessive hydrolysis and high-temperature treatment reduced RS formation. FTIR and DSC analyses confirmed a progressive loss of short-range order and crystallinity, with gelatinization enthalpy decreasing from 6.28 to 0.35 J/g as hydrolysis increased. SEM confirmed a progressive transition from porous, interconnected networks to compact, collapsed matrices as temperature and hydrolysis increased. Partial depolymerization promoted molecular reorganization without compromising network formation. These findings demonstrate that thermo-enzymatic processing modulates starch structure, digestibility, and gelation for tailored food and biopolymer applications.
Chronic diabetic wounds are characterized by persistent bacterial infection, biofilm formation, and dysregulated inflammation, which impair angiogenesis and delay healing. In this work, we developed a multifunctional injectable hydrogel (ZE-OSG) that integrates ZnO2-based chemodynamic therapy (CDT) with the bioactivity of ginger-derived extracellular vesicles (EVs) to eradicate biofilms, resolve inflammation, and promote vascular regeneration. ZnO2-EV nanohybrids were synthesized via biomineralization of ZnO2 directly onto EV, preserving EV bioactivity while enabling localized generation of hydrogen peroxide (H₂O₂) and hydroxyl radicals (·OH). This facilitates potent eradication of methicillin-resistant Staphylococcus aureus (MRSA) and disruption of mature biofilms. After integrating to Schiff base-crosslinked oxidized starch-gelatin hydrogel (OSG), the ZE-OSG hydrogel exhibited injectability, self-healing ability, and prolonged retention at the wound site. In a diabetic mouse model of MRSA-infected wounds, ZE-OSG significantly accelerated wound closure, reduced bacterial burden, suppressed inflammatory cytokines, promoted M1 to M2 macrophage polarization, and enhanced collagen deposition and neovascularization through upregulation of vascular endothelial growth factor (VEGF) and CD31 expression, without systemic toxicity. By integrating the EVs bioactivity with ZnO2-mediated antibacterial CDT within a single injectable hydrogel, ZE-OSG offers a clinically translatable strategy for the comprehensive management of infected chronic wounds.
Conventional polyethylene mulch films cause severe “white pollution,” while existing biodegradable alternatives either pose ecological risks or suffer from limited functionality, making it difficult to simultaneously achieve the dual agronomic requirements of high reflectance for yield enhancement and low transmittance for weed suppression. A Janus-type light-managing cellulose-based composite mulch film (JCMF) was fabricated via a facile vacuum-assisted self-assembly followed by hot-pressing. The film consists of an upper reflective layer (RL) containing hydrophobic Al2O3 and a lower light-blocking layer (LBL) loaded with biochar, for the first time integrating active agronomic light management in a biodegradable mulch film. The optimized JCMF30 exhibited a synergy of high visible-light reflectance (90.1 ± 0.7%), low visible-light transmittance (0.57 ± 0.12%), high tensile strength (29.8 ± 4 MPa), and high hydrophobicity (140.3 ± 1.8°), along with an appropriate water vapor transmission rate (WVTR, 473.5 ± 9.9 g·(m2·24 h)−1. Accelerated aging and soil burial tests further confirmed that JCMF30 possesses excellent weatherability and a favorable degradation rate (72.1 ± 3.3% weight loss after 135 d). This study provides a new paradigm for developing next-generation agricultural mulch films that integrate active agronomic light management with environmental friendliness.
The uncontrollable growth of lithium dendrites triggers battery short circuits, thermal runaway, and even explosions. In this work, a novel safe sandwich-structured bacterial nanocellulose (BNC) separator (SBCB) was designed. In order to facilitate scaling up and future industrialization, a conventional industrial static fermentation method was employed for its preparation. The intermediate layer features a conductive network constructed by the pristine three-dimensional (3D) nanoscale network structure of BNC interconnected with carboxylated multi-walled carbon nanotubes (MWCNTs-COOH). When lithium dendrites penetrate the conductive intermediate layer of SBCB, an electrical signal warning is triggered, enhancing battery safety. Moreover, leveraging the advantages of BNC, the separator exhibits no observable macroscopic dimensional shrinkage at 200 °C, with its natural nano-network pores enabling high electrolyte uptake (536.1%). The internal hydrogen bonds endow it with exceptional tensile strength (193.39 MPa) and puncture resistance (5.24 N). The uniformly interconnected pore structure facilitates efficient lithium-ion transport (tLi+ = 0.59), enabling stable lithium plating/stripping behavior for approximately 4500 h in LiLi cells. In LiFePO4-Li cells, it achieves 200 cycles at 0.2C with 92% capacity retention. These results indicated that the SBCB separator would provide a new strategy for addressing the lithium dendrite issue and offer a simple, bio-based, and potentially sustainable technological pathway.
