Ammonia fiber expansion-assisted deep eutectic solvent treatment for wheat straw fraction separation and bioconversion.

In this study, an ammonia fiber expansion (AFEX)-assisted deep eutectic solvent (DES) pretreatment method was developed for the rapid separation of wheat straw fractions, which reduced the pretreatment time for DES and improved the pretreatment efficiency. This study describes the feasibility of the AFEX-assisted DES pretreatment in terms of both progressive and parallel relationships and analyzes the subsequent enzymatic effect in generating glucose from cellulose. Ammonia fiber expansion-assisted DES one-pot pretreatment at 120 °C, for 1.5 h resulted in an enzymatic efficiency of 98.0 ± 3.1 %. Moreover, the enzyme efficiency remained greater than 85 % after three recovery cycle experiments. The comparison between regenerated-lignin (d-lignin) and alkaline-lignin showed that regenerated lignin has a lower molecular weight and belongs to para-hydroxy-phenyl-guaiacyl-syringyl (H-G-S) type lignin. This study developed is a green and efficient pretreatment process with great potential in the separation and utilization of biomass fractions.

Non-fouling polymer brush grafted fluorine-doped tin oxide enabled optical and chemical enhancement for sensitive label-free antibody microarrays.

Oblique-incidence reflectivity difference (OIRD) is a compelling technique for real-time, label-free and non-destructive detection of antibody microarray chips, but its sensitivity needs essential improvement for clinical diagnosis. In this study, we report an innovative high-performance OIRD microarray by using poly[oligo(ethylene glycol) methacrylate-co-glycidyl methacrylate] (POEGMA-co-GMA) brush grafted fluorine-doped tin oxide (FTO) as the chip substrate. The polymer brush enhances the interfacial binding reaction efficiency of targets from the complicated sample matrix due to its high antibody loading and excellent anti-fouling merits; the FTO-polymer brush layered structure, on the other hand, excites the interference enhancement effect of OIRD to achieve enhanced intrinsic optical sensitivity. Synergistically, the sensitivity of this chip is significantly improved compared to rival chips, achieving a limit of detection (LOD) as low as 25 ng mL-1 for the model target C-reactive protein (CRP) in 10% human serum. This work explores the tremendous influence of the chip interfacial structure on the OIRD sensitivity and proposes a rational interfacial engineering strategy to boost the performance of the label-free OIRD based microarray and other bio-devices.

Rational Design of Mesoporous Coordination Polymer Nanophotosensitizers for Photodynamic Tumor Ablation.

Effective clinical practice of precise photodynamic therapy (PDT) is severely impeded by the inherent drawbacks and aggregation propensity of conventional photosensitizers. An all-in-one approach is highly desired to optimize structural features, photophysical properties, and pharmacokinetic behaviors of photosensitizers. Herein, we have fabricated mesoporous boron dipyrromethene-bridged coordination polymer nanophotosensitizers (BCP-NPs) for high-performance PDT via a unique solvent-assisted assembly strategy. Distinctive photophysical and structural characteristics of BCP-NPs confer enhanced photodynamic activities, together with high cellular uptake and ultrahigh stability. Moreover, BCP-NPs showed excellent tumor accumulation and prolonged tumor retention, achieving eradication of the triple-negative breast cancer (TNBC) model under low-power-density LED irradiation. This work has provided a valuable paradigm for the construction of mesoporous photoactive nanomaterials for biophotonic applications.

The individual and combined effects of polystyrene and silver nanoparticles on nitrogen transformation and bacterial communities in an agricultural soil.

The effects of emerging contaminants micro/nanoplastics (MPs/NPs) and silver nanoparticles (Ag NPs) on health have attracted universal concern throughout the world. However, it is unclear on the combined effects of MPs/NPs and Ag NPs on the biogeochemistry cycle such as nitrogen transformation and functional microorganism in the soil. In the present study, we conducted a 45-day soil microcosm experiment with polystyrene (PS) MPs/NPs and Ag NPs to investigate their combined impact on nitrogen cycling and the bacterial community. The results showed that MPs or NPs exerted limited effects on nitrogen transformation in the soil. The combined effects of PS MPs/NPs and Ag NPs were mainly caused by the presence of Ag NPs. However, PS NPs alleviated the inhibition of anammox and denitrification induced by Ag NPs via upregulating anammox-related genes and elevating nitrate and nitrite reductase activities. PS MPs + Ag NPs treatment significantly reduced bacterial diversity. PS MPs/NPs + Ag NPs increased the relative abundances of denitrifying Cupriavidus by 0.32% and 0.06% but decreased nitrogen-fixing functional microorganisms of Microvirga (by 2.05% and 2.24%), Bacillus (by 0.16% and 0.22%), and Herbaspirillum (by 0.14% and 0.07%) at the genus level compared with Ag NPs alone. The significant downregulation of nitrogen-fixing genes (K02586, K02588, and K02591) was observed in PS MPs/NPs + Ag NPs treatment compared to Ag NPs in the nitrogen metabolism pathway. Moreover, g-Lysobacter and g-Aquimonas were identified as biomarkers in PS MPs + Ag NPs and PS NPs + Ag NPs by LEfSe analysis. Our study sheds the light that changes of functional microorganism abundances contributed to the alteration of nitrogen transformation. Taking the particle size of plastics into account will be helpful to accurately assess the combined ecological risks of plastics and nanomaterial contaminants.

Soil biofilm formation enhances microbial community diversity and metabolic activity.

Biofilms have been extensively studied in aquatic and clinical environments. However, the complexity of edaphic microenvironment hinders the advances toward understanding the environmental functionalities and ecological roles of soil biofilms. In this work, artificial soil was employed to investigate the soil biofilm formation and corresponding impacts on community structure and microbial activities. Our results showed that extracellular polymeric substances (EPS) production was significantly enhanced and micro-meter sized cell aggregates formed with high glucose amendment. Biofilm development exhibited significant effects on the soil microbial processes. 16S rRNA gene sequencing demonstrated the soils with biofilms and free-living cells shared similar microbial communities. But the Shannon diversity and evenness indices of communities with soil biofilms were significantly enhanced by 18.2% and 17.1%. The soil with biofilms also revealed a rapid response to nutrient provision and robust microbial activity, which consumed 65.4% more oxygen in the topsoil (0-1.5 mm). Kinetic respiration analysis showed that the enhanced metabolic activity was attributed to 23-times more active microbes in soil biofilms. In summary, this study revealed that soil biofilms can sustain a diverse and robust community to drive soil biogeochemical processes.

Growth and accelerated differentiation of mesenchymal stem cells on graphene-oxide-coated titanate with dexamethasone on surface of titanium implants.

OBJECTIVE: In this study, the objective is to construct graphene-oxide-coated titanate on titanium foils as drug vehicle to enhance cell proliferation and osteo-differentiation of rat bone mesenchymal stem cells (rBMSCs). METHODS: Graphene oxide (GO) sheets obtained using the modified Hummer's method and characterized by AFM were coupled with bioactive titanate on Ti implants (GO-Ti) pretreated by alkali, followed by reduction (rGO-Ti). They were characterized by Raman spectroscopy, XPS, SEM, FTIR and contact angle. After dexamethasone (DEX) was loaded onto them (DEX-GO-Ti and DEX-rGO-Ti), cell proliferation of rBMSCs on them was evaluated by CCK-8 and F-actin staining, and differentiation through alkaline phosphatase activity, mRNA expression, and calcium nodules. RESULTS: The obtained GO sheets were monolayers from AFM. Raman spectra exhibited two prominent peaks at D and G bands, and the I(D)/I(G) ratios increased from 0.96 to 1.68 after reduction. XPS proved the existence of oxygenated functional groups for GO-Ti and the reduction of their intensity for rGO-Ti. From SEM, GO and rGO were evenly coated on nanostructures. DEX-GO-Ti absorbed most amount of DEX and released in a sustained manner. CCK-8 results showed that DEX-GO-Ti showed excellent performance on promoting cell proliferation. RMBSCs on DEX-GO-Ti presented greatly high expression of calcium, proteins and mRNA related to osteogenic differentiation. SIGNIFICANCE: GO coated titanate nanostructrues on surfaces of Ti foils by a simple self-assembly method, showed excellent vechiles for DEX. The construct promoted proliferation and accelerated osteogenic differentiation of rBMSCs, and would be prosperous for their further applications.