ACS Applied Bio Materials最新文献

Currently, ofloxacin (OFX) is widely used in various medical treatment and aquaculture industries. However, its production and application produces waste which pollutes the natural environment and causes ecological damage. The application of biochar is a crucial way to remove OFX antibiotics from wastewater. In this paper, bagasse was used as the material to be pyrolyzed to obtain bagasse biochar (BC). BC was modified with HNO₃ and KOH to prepare acid-modified sugarcane biochar (HBC) and alkali-modified sugarcane biochar and subsequently applied to the treatment of ofloxacin wastewater. The results showed that the adsorption capacity of HBC was 2.2 times higher than that of BC, and it had better adsorption performance. When the dosage of acid-modified biochar was 1 g/L and the initial pH of the solution was 7.0, the OFX removal rate reached 88.5% after 90 min of reaction. HBC has good stability, and the OFX removal efficiency is still up to 78.5% after 5 cycles. According to the adsorption simulation results, the adsorption of the three biochar materials is more consistent with the Freundlich adsorption model, and the simulated linear correlation coefficient is higher than 0.99. The K_fr value of HBC is 6.6042, which exhibits the highest adsorption capacity. Moreover, the three biochars exhibit better simulation results in pseudo-second-order kinetics fitting, and the linear correlation coefficients are above 0.99. The adsorption mechanism of bagasse biochar for ofloxacin in wastewater was π-π electron donor-acceptor interactions. The results show that bagasse biochar has good feasibility in the treatment of ofloxacin wastewater.

In this study, eggshell-derived CaCO₃ ultrafine powder was prepared from waste eggshell with the method of omnidirectional planetary ball mill. The particle size distribution was measured by laser particle size analyzer. Then, the parameters of grinding kinetic equation of eggshell powder were obtained by software fitting, and the grinding model and characteristic equation of particle-size distribution of the eggshell-derived CaCO₃ powder were discussed. The results showed that the best grinding conditions were as follows: using 3 mm zirconia grinding ball, 400 rpm, 50% filling rate, 50% slurry concentration, and ball-milling time of 30 min. The grinding kinetic equation can well simulate the eggshell crushing process. The equation showed that with the prolongation of milling time, the large particle size of the eggshell powder gradually decreased, and the milling efficiency was 0 after 60 min. The Rosin-Rammler-Bennet distribution model could be used to describe the distribution characteristics of the cumulative particle size of the eggshell powder, and the fitting degree of particle size distribution at each milling time could reach R²> 0.99. No chemical change occurred in the eggshell powder before and after grinding. However, the calcite crystal structure of eggshell-derived CaCO₃ ultrafine powder becomes incomplete.

Typical value-added platform chemicals 5-hydroxymethylfurfural (HMF) and levulinic acid (LA) can be obtained from hexoses under microwave hydrothermal (MHT) conditions. This study explored the detailed transformation process regarding the MHT products in acidic seawater obtained using glucose and fructose as raw materials. The facile conversion of fructose compared with glucose was mainly ascribed to their different activation energies (56.721 and 88.594 kJ mol^-1, respectively). The HMF and LA product yields were strongly affected by the MHT temperature and holding time in two types of hexose solution. Undesirable humins were found to inevitably form under each set of reaction conditions. The carbon balance results for reactants and products showed that up to 60% of fructose carbon was converted into value-added chemicals, while 47% of glucose carbon underwent the same conversion in acidic seawater under the optimal MHT conditions. This study provides further knowledge regarding the role of microwave heating combined with acidic seawater in green chemistry and is a useful reference for the biorefinery industry.

Municipal solid waste management (MSWM) remains a major concern in Sri Lanka, and various treatment methods have been deployed. Though both composting and anaerobic digestion have been effective in environmental decontamination, there are other environmental issues that should be assessed. This study aimed to evaluate the environmental impacts of a full-scale composting plant and an anaerobic digestion plant for managing the organic fraction of municipal solid waste (OFMSW) in Sri Lanka using life cycle assessment (LCA). The results show that OFMSW composting causes unfavourable environmental impacts on damage categories such as human health (6.77 × 10^-4 disability-adjusted life years (DALY) tonne^-1 OFMSW), ecosystem quality (1.90 × 10^-6 species.year tonne^-1 OFMSW), and resource scarcity (3.66 × 10^-1 United States Dollar (USD) tonne^-1 OFMSW). Anaerobic digestion also leads to unfavourable impacts on human health (2.13 × 10^-4 DALY tonne^-1 OFMSW) and ecosystem quality (6.46 × 10^-7 species.year tonne^-1 OFMSW). However, the impact on resource scarcity (-3.85 × 10^-2 USD tonne^-1 OFMSW) was avoided due to electricity production via anaerobic digestion. Specifically, the treatment of OFMSW by anaerobic digestion resulted in a reduction by 68.3% in the total environmental load as compared to composting. It can be concluded that out of the two existing systems investigated, anaerobic digestion has a more favourable environmental impact than composting.

Chicken feathers are hazardous to the environment because of their poor digestibility and potential as a source of environmental contaminants. However, this waste contains valuable plant nutrients that can be recovered and used to improve soil fertility and agricultural productivity. The objectives of this study were to evaluate how effective vermicomposting is at recovering nutrients and changes in enzymatic activity during vermicomposting of hydrolysed chicken feather residues (HCFR). The study included four treatments with three replications at different HCFR and pelletized wheat straw (PWS) mixing proportions: (T1) 25% HCFR+75% PWS with earthworms, (T2) 25% HCFR+75% PWS without earthworms, (T3) 50% HCFR+50% PWS with earthworms, and (T4) 50% HCFR+50% PWS (w/w) without earthworms. Eisenia andrei was used in the experiment for 120 days. Earthworm treatments recovered more available plant nutrients than non-earthworm treatments by 14% $N-{\mathrm{NO}}_3^{-}$ (T1); 50% K (T3); 47% Mg (T3); 75% P (T3); 55% B (T3); 34% Cu (T3); 40% Fe (T1); 46% Mn (T3); 11% Zn (T1). However, $N-{\mathrm{NH}}_4^{+}$ was significantly reduced by -80% (T1). Acid phosphatase, arylsulphatase, alanine aminopeptidase, and leucine aminopeptidase were more active in the treatments with earthworms and positively correlated with P and C: N ratio. Alanine aminopeptidase (3752 µmol AMCA.g^-1.h^-1) and leucine aminopeptidase (4252 µmol AMCL.g^-1.h^-1) had higher activities in T3 on day 60 of vermicomposting. As a result, the earthworm treatment recovers more plant nutrients than the non-earthworm treatments, and it can be recommended as a better vermicomposting approach for nutrient recovery from HCFR.

Antimicrobial resistance is growing among the causative agents of bacterial meningitis, Neisseria meningitidis and Streptococcus pneumoniae, which trigger detrimental neuroinflammatory responses within the central nervous system. Here, we evaluated the antimicrobial potential of DNA-templated and stabilized silver nanoclusters (AgNCs). AgNCs were templated on a single hairpin (HP) or fibrous hairpin structures (HP-F). HP-F provided higher local concentrations of AgNCs, when compared to HP, and exhibited stable physicochemical properties and potent antimicrobial activity. Furthermore, at low silver concentrations, AgNCs restricted bacterial survival and reduced inflammatory responses in microglia without causing cytotoxicity, supporting further development of AgNCs as therapeutics for meningitis.

Bypass vascular grafting is an effective treatment for cardiovascular disease. Currently, small-diameter vascular grafts (SDVGs, inner diameter <6 mm) for peripheral revascularization, especially for lower limb revascularization, are in high demand. Previously, we prepared and investigated PLGA@PCL SDVGs with core/shell fibers. In this study, PLGA@PCL/elastin core/shell fibers (PCEs) SDVGs were further prepared by electrospinning, so as to enhance the vascular regeneration performance through the introduction of exogenous soluble elastin. The cross-linking effects of elastin with different cross-linking reagents on PCEs SDVGs were subsequently explored. Among them, PCEs SDVGs cross-linked with 1-ethyl-3-(3-(dimethylamino)propyl) carbodiimide (EDCI) and N-hydroxysuccinimide (NHS) retained the most soluble elastin content and achieved a compliance of 1.74 ± 0.62%/mmHg × 10^–2, a bursting pressure of 1750 mmHg, and a tensile strength of 2.09 ± 0.51 MPa, which are mostly close to those of human saphenous vein. Subsequently, in vivo transplantation in the abdominal aorta showed that all implanted SDVGs cross-linked by EDC/NHS (PCEsEN) remained patent without aneurysm formation. Histological staining results further showed that the introduction of elastin not only promoted the degradation of SDVGs but also accelerated the formation of neointimal tissue and suppressed the calcification. Thus, PCEsEN shows promising potential to be translated into SDVGs in clinic.

An effective wound dressing should be hemostatic and able to absorb excess exudates while protecting the wound from infection and inflammation. However, conventional dressings with a single structure and property exist with non-negligible limitations in exudate management owing to their limited draining ability. Herein, a self-pumping Janus hemostatic dressing with unidirectional moisture transport (Janus@BG5) was reported by an electrospun trilayered fibrous matrix, in which the inner hydrophobic polylactic acid (PLA) nanofiber array, the interlayer PLA and silk fibroin (SF) composite fibrous layer (P2S8), and the outer hydrophilic nanofiber network are introduced with inorganic bioactive glass (Ce-BG@PDE). Ce-BG@PDE nanoparticles were developed by coating polydopamine (PDA) and ε-polylysine (EPL) in sequence on the basis of cerium-doped bioactive glass (Ce-BG) nanoparticles. The Janus@BG5 with 88.0% porosity exhibited a tensile strength of 3.4 MPa. The Janus@BG5 displayed the unidirectional moisture transport capability, causing a one-way flow of the excess serum from the hydrophobic to the hydrophilic side. In subsequent bacterial studies, the Janus@BG5 could effectively inhibit Escherichia coli (82.9 ± 2.7%) and Staphylococcus aureus (90.5 ± 0.7%) colonization. In comparison to conventional medical gauze, the blood absorption rate of the Janus@BG5 was 643.0%, and the clotting index for Janus@BG5 was 25.8%, and its coagulation time is 237.0 ± 10.5 s. In vitro cytotoxicity evaluation based on human umbilical vein endothelial cells (HUVECs) revealed that all samples had no cytotoxicity. These results indicated the suitability of such a trilayered Janus nanofibrous membrane for its potential application in hemostatic wound dressing management.

Rheumatoid arthritis (RA) is an autoimmune disorder marked by chronic joint inflammation and tissue damage. While current systemic therapies mainly reduce inflammation, they often lack regenerative capacity and cause off-target effects. To address this, we developed an injectable collagen–hyaluronic acid (Col-HA-NHS) hydrogel for intra-articular delivery of umbilical mesenchymal stem cell (UMSC) spheroids. The hydrogel demonstrated excellent shear-thinning and regelable properties, biocompatibility, and controlled degradation. Encapsulated UMSC spheroids (S-UMSCs) exhibited enhanced paracrine function, secreting higher levels of growth factors such as epidermal growth factor (EGF) and fibroblast growth factor (FGF) than those of monolayer cultures. In vitro, the hydrogel–spheroid system (CH/S-UMSCs) significantly inhibited M1 macrophage polarization, as indicated by reduced CD86 expression, and decreased intracellular reactive oxygen species (ROS). In a rat collagen-induced arthritis (CIA) model, intra-articular administration of CH/S-UMSCs led to the most pronounced reduction in paw swelling and the highest clinical healing score among all groups. Histopathological and micro-CT analyses further revealed that this treatment markedly alleviated synovial inflammation, mitigated cartilage erosion, and suppressed bone destruction, while significantly improving bone mineral density (BMD) and trabecular microstructure. This combinatory strategy thus provides a synergistic therapy integrating immunomodulation and tissue regeneration, offering a promising localized treatment for RA.