Nanoscale Composite Lignin Colloids with Tunable Visible Colors Used for Anti-UV Cosmetics.

Nanoscale composite lignin colloids were prepared on a large scale with a process of assembly-mediated internal cross-linking in a good solvent, thus possessing absolutely nanoscale dimensions, excellent robustness, and less aggregation. The therefore prime UV resistance and various natural visible colors contribute to the preservation and beautification of skin.

Multiple surface lattice resonances of overlapping nanoparticle arrays with different lattice spacing.

Multiple surface lattice resonances generated with nanoparticle arrays are promising to enhance light-matter interactions at different spectral positions simultaneously, and it is important to tailor these resonances to desired frequencies for practical applications such as multi-modal nanolasing. To this end, this study proposes to generate multiple surface lattice resonances using overlapping nanoparticle arrays with different lattice spacing. Both full-wave numerical simulations and analytical coupled dipole approximation calculations reveal that for the overlapping structures composed with two different gold nanosphere arrays, both surface lattice resonances for the element structures are effectively excited. Considering that the optical responses are governed by the dipole-dipole interactions between the nanoparticles, it is interesting to find that the multiple surface lattice resonances are almost invariant by adjusting the relative shifts between the two arrays, which can be useful to tailor the high-quality factor resonances to desired spectral positions. In addition, due to the same reason, it is also shown that the multiple surface lattice resonances can be further finely tuned by selectively removing specific nanoparticles in the array. We anticipate that the tolerance to generate multiple surface lattice resonances and the flexible tunability make the overlapping nanoparticle arrays useful to design high performance linear and nonlinear nanophotonic devices.

Multi-mode strong coupling in Fabry-Pérot cavity-WS2 photonic crystal hybrid structures.

Optical microcavities embedded with transition metal dichalcogenide (TMDC) membranes have been demonstrated as excellent platforms to explore strong light-matter interactions. Most of the previous studies focus on strong coupling between excitons of unpatterned TMDC membranes and optical resonances of various microcavities. It is recently found that TMDC membranes patterned into photonic crystal (PhC) slabs can sustain guided-mode resonances that can be excited and probed by far-fields. Here, we present a comprehensive theoretical and numerical study on optical responses of Fabry-Pérot (F-P) cavity-WS2 PhC hybrid structures to investigate the multi-mode coupling effects between excitons, guided-mode resonances and F-P modes. We show that both the exciton resonance and the guide-mode resonance of the WS2 PhC can strongly interact with F-P modes of the cavity to reach strong coupling regime. Moreover, a Rabi splitting as large as 63 meV is observed for the strong coupling between the guided-mode resonance and the F-P mode, which is much larger than their average dissipation rate. We further demonstrate that it is even possible to realize a triple mode strong coupling by tuning the guide-mode resonances spectrally overlapped with the exciton resonance and the F-P modes. The hybrid polariton states generated from the triple mode coupling exhibit a Rabi splitting of 120 meV that greatly exceeds the criterion of a triple mode strong coupling (∼29.3 meV). Our results provide that optical microcavities embedded with TMDC PhCs can serve as promising candidates for polariton devices based on multi-mode strong coupling.

Preparation and characterization of bifunctional wolfsbane-like magnetic Fe3O4 nanoparticles-decorated lignin-based carbon nanofibers composites for electromagnetic wave absorption and electrochemical energy storage.

Recently, with the pursuit of high-efficiency electromagnetic wave absorption (EMWA) and electrochemical energy storage (EES) materials, multifunctional lignin-based composites have attracted significant interest due to their low cost, vast availability, and sustainability. In this work, lignin-based carbon nanofibers (LCNFs) was first prepared by electrospinning, pre-oxidation and carbonization processes. Then, different content of magnetic Fe3O4 nanoparticles were deposited on the surface of LCNFs via the facile hydrothermal way to produce a series of bifunctional wolfsbane-like LCNFs/Fe3O4 composites. Among them, the synthesized optimal sample (using 12 mmol of FeCl3·6H2O named as LCNFs/Fe3O4-2) displayed excellent EMWA ability. When the minimum reflection loss (RL) value achieved -44.98 dB at 6.01 GHz with an thickness of 1.5 mm, and the effective absorption bandwidth (EAB) was up to 4.19 GHz ranging from 5.10 to 7.21 GHz. For supercapacitor electrode, the highest specific capacitance of LCNFs/Fe3O4-2 reached 538.7 F/g at the current density of 1 A/g, and the capacitance retention remained at 80.3 %. Moreover, an electric double layer capacitor of LCNFs/Fe3O4-2//LCNFs/Fe3O4-2 also showed a remarkable power density of 7755.29 W/kg, outstanding energy density of 36.62 Wh/kg and high cycle stability (96.89 % after 5000 cycles). In short, the construction of this multifunctional lignin-based composites has potential applications in electromagnetic wave (EMW) absorbers and supercapacitor electrodes.

N-S co-doping lignin-based carbon magnetic nanoparticles as high performance supercapacitor and electromagnetic wave absorber.

Recently, multifunctional lignin-based materials are gaining more and more attention due to their great potential for low-cost and sustainability. In this work, to obtain both an excellent supercapacitor electrode and an outstanding electromagnetic wave (EMW) absorber, a series of multifunctional nitrogen-sulphur (N-S) co-doped lignin-based carbon magnetic nanoparticles (LCMNPs) had been successfully prepared through Mannich reaction at different carbonization temperature. As compared with the directly carbonized lignin carbon (LC), LCMNPs had more nano-size structure and higher specific surface area. Meanwhile, with the increase of carbonization temperature, the graphitization of the LCMNPs could also be effectively improved. Therefore, LCMNPs-800 displayed the best performance advantages. For the electric double layer capacitor (EDLC), the optimal specific capacitance of LCMNPs-800 reached 154.2 F/g, and the capacitance retention after 5000 cycles was as high as 98.14 %. When the power density was 2204.76 W/kg, the energy density achieved 33.81 Wh/kg. In addition, N-S co-doped LCMNPs also exhibited strong electromagnetic wave absorption (EMWA) ability, whose the minimum reflection loss (RL) value of LCMNPs-800 was realized -46.61 dB at 6.01 GHz with an thickness of 4.0 mm, and the effective absorption bandwidth (EAB) was up to 2.11 GHz ranging from 5.10 to 7.21 GHz, which could cover the C-band. Overall, this green and sustainable approach is a promising strategy for the preparation of high-performance multifunctional lignin-based materials.

Resonance coupling between chiral quasi-BICs and achiral molecular excitons in dielectric metasurface J-aggregate heterostructures.

The realization of flexible tuning and enhanced chiral responses is vital for many applications in nanophotonics. This study proposes to manipulate the collective optical responses with heterostructures consisting of chiral dielectric metasurfaces and achiral J-aggregates. Owing to the resonance coupling between the chiral quasi-bound states in the continuum (QBICs) and the achiral exciton mode, large mode splitting and anticrossing are observed in both the transmission and circular dichroism (CD) spectra, which indicates the formation of hybrid chiral eigenmodes and the realization of the strong coupling regime. Considering that the radiative and dissipative damping of the hybrid eigenmodes depends on the coherent energy exchange, the chiral resonances can be flexibly tuned by adjusting the geometry and optical constants for the heterostructure, and the CD of the three hybrid eigenmodes approach the maximum (∼1) simultaneously when the critical coupling conditions are satisfied, which can be promising for enhanced chiral light-matter interactions.

Perfect absorption and phase singularities induced by surface lattice resonances for plasmonic nanoparticle array on a metallic film.

The formation of pairs of perfect absorption associated with phase singularities in the parameter space using the hybridized structure constructed with a metallic nanoparticle array and a metallic film is promising to enhance light-mater interactions. However, the localized plasmon resonances of the array possess strong radiative losses, which is an obstacle to improve the performances for many applications. On the contrary with the subwavelength array hybridized structure, this study shows that by enlarging the lattice spacing, the oscillator strength of the nanoparticles can be enhanced with the formation of surface lattice resonance, thereby leading to similar but much narrower pairs of perfect absorption due to the interactions with the Fabry-Pérot cavity modes. Furthermore, when the surface plasmon polariton mode shift to the same spectral range associated with the enlarged lattice spacing, the coupling and mode hybridization with the surface lattice resonance result in an anticrossing in the spectra. Although the resonance coupling does not enter the strong coupling regime, the quality factors (∼ 134) and near-field enhancements (∼ 44) are strongly enhanced for the hybridized resonance modes due to the effectively suppressed radiative losses compared with that of the localized plasmon resonances, which make the hybridized structure useful for the design of functional nanophotonic device such as biosensing, multi-model nanolasing, and high-quality imaging.

Involvement of the sensorimotor system in less advanced L2 processing: Evidence from a semantic category decision task.

There is increasing evidence indicating that the sensorimotor system is involved in advanced L2 processing, which raises the question of what role sensorimotor information plays in the course of less advanced L2 comprehension. In the current study, two experiments were conducted using a lexical decision task (LDT) and semantic category task (SCT). The results showed that, in the LDT, a task more likely to result in participants making judgments based on the physical properties of words (e.g., familiarity, orthography), "up" words (e.g., sun, plane) did not result in faster upward than downward responses, and "down" words (e.g., tunnel, cave) also did not result in faster downward than upward responses. In the SCT, compatibility effects were found; specifically, searching for the up target after "up" words was faster than after "down" words and searching for the bottom target after "down" words was faster than after "upward-pointing" words. Hence, we concluded that L2 sensorimotor association, at least for L2 with low proficiency, not automatic in nature and is dependent upon deeper semantic task demands.

Comparison of tissue distribution of free and protein bound Nɛ-carboxymethyllysine after long-term oral administration to mice.

Nɛ-Carboxymethyl-lysine (CML) is a primary advanced glycation end product that exists in the body and food as free and bound forms with different bioavailability and physiological effects. To compare the uptake, tissue distribution, and fecal excretion of dietary free and bound CML, free or bound CML were administered to healthy mice at 10 mg CML kg-1 body weight per day for 12 weeks. The results demonstrated that free CML was significantly absorbed in serum and accumulated in the colon, ileum, lung, kidneys, heart, spleen, brain, and liver after intake of free and bound CML, whereas no statistical increase was found in the accumulation of bound CML in the serum, lung, spleen, kidneys, and liver. The colon was the main tissue for the accumulation of free and total CML. Moreover, the accumulation of free CML in tissues and organs was significantly correlated with free CML levels in serum. In conclusion, consumption of bound CML caused a higher uptake, accumulation, and fecal excretion of CML in the body than intake of free CML.

Fabrication of uniform lignin nanoparticles with tunable size for potential wound healing application.

The construction of lignin nanoparticles (LNPs) with both lignin properties and nanomaterial properties through controlling the morphologies and structures of lignin is one of the effective ways to realize its application in the field of biomedicine. Firstly, the morphology and chemical structure of LNPs were studied in detailed. The results showed that the chemical structural characteristics of LNPs had not changed significantly and its morphology was more regular shape and narrower size distribution (50-350 nm). Besides, LNPs also exhibited excellent water dispersion stability and high negative zeta potential. Subsequently, LNPs as wound dressings had good antioxidant property, excellent adsorption capacity of protein, outstanding bactericidal activity and remarkable biocompatibility, suggesting that LNPs did not interfere with cell proliferation during wound healing. Finally, the in vivo results of mouse wounds further illustrated that treatment of wounded skin wounds with LNPs enhanced its effective healing. After 15 days, as compared with the untreated control and original lignin (OL) groups, the wounds treated of LNPs was completely closed and granulation tissue formation was advanced. Overall, this study can be a good method for high-value applications of LNPs, and highlighting the advantages of using lignin as medical adjuvant nanomaterials to accelerate wound healing.

Isoxanthanol has protective and anti-inflammatory effects on subchondral bone deterioration in experimental osteoarthritic rat model.

In the present study isoxanthanol was investigated for treatment of monosodium iodoacetate (MIA)-induced osteoarthritis (OA) in vivo. The study demonstrated that isoxanthanol inhibited excessive release of interleukin-6, NO and PGE2 in RAW264.7 cells treated with LPS in dose dependent manner. The effects of isoxanthanol were examined in a rat model of osteoarthritis (OA) and observed to amelio-rate inflammatory damage and protect against OA. Moreover, in vivo data also confirmed inhibition of interleukin-6, NO and PGE2 levels in LPS-induced OA-rats. Deterioration of knee subchondral bone in LPS-induced OA-rats was also prevented effectively by isoxanthanol-treatment. Therefore, isoxanthanol prevents subchondral bone deterioration in OA rats via targeting inflammatory processes.

Multifunction lignin-based carbon nanofibers with enhanced electromagnetic wave absorption and surpercapacitive energy storage capabilities.

It is difficult for green sustainable lignin-based materials to simultaneously obtain efficient electromagnetic wave absorption (EMWA) and supercapacitive energy storage (SCES), which has not yet been reported. Herein, the light-weight lignin-based carbon nanofibers (LCNFs) with proper pore size, well graphitization degree, and heteroatom doping were tailored through electrospinning and carbonization processes. Interestingly, the graphitization degree and porous structure of LCNFs could be easily adjusted by changing the activating temperature, and the higher conductivity was achieved for preparing LCNFs at higher activating temperature due to the differences in the crystal size and activating degree of LCNFs. As a result, in the field of EMWA, the LCNFs-950 exhibited the minimum reflection loss (RL) value was -41.4 dB and the absorbing frequency was 9.05 GHz at 2.5 mm thickness, which meant this absorbent could absorb and/or dissipate more than 99.9% of incident electromagnetic wave (EMW). Furthermore, the LCNFs-950 also exhibited excellent SCES ability. In two-electrode system, the optimal LCNFs-950 symmetric supercapacitor specific capacitance reached 139.4 F/g at a current density of 0.5 A/g, meanwhile, the energy density was 41.4 Wh/kg at a power density of 3500 W/Kg. These multifunctional features of LCNFs will be highly promising for the next-generation environmental remediating materials.

Self-assembled/composited lignin colloids utilizing for therapy, cosmetics and emulsification.

Lignin, the most abundant source of renewable aromatic compounds on the planet, is attracting more scholarly attention due to its possibility of replacing petroleum-based chemicals and products. However, it remains underutilized because of the heterogeneity of its multi-level structure that prevents homogenization and standardization of derived products. The key to solving these problems lies in finding a general preparation method to achieve the integrated utilization of lignin molecules at all levels. The assembly-mediated granulation methods provide a significant means for the integrated value-added utilization of lignin, and for biomass productization applications, it is significant to understand the molecular mechanisms of lignin nano-colloids (LNCs) formation thus accurately guiding their functionalization. Therefore, a thorough understanding of the assembly morphology and behavior of lignin in different solutions towards colloids is of great scientific importance. In this minireview, we focus on the assembly behavior of lignin in different solvents, specifically in mono-solvent and multi-solvent, and in particular, we review various methods for preparing lignin composite colloids and concentrate on the applications in therapy, cosmetics and emulsification, which are important for guiding the preparation and efficient utilization of LNCs.

Vascular transplantation with dual-biofunctional ePTFE vascular grafts in a porcine model.

Cardiovascular disease (CVD) poses serious health concerns worldwide. The lack of transplantable vascular grafts is an unmet clinical need in the surgical treatment of CVD. Although expanded polytetrafluoroethylene (ePTFE) vascular grafts have been used in clinical practice, a low long-term patency rate in small-diameter transplantation application is still the biggest challenge. Thus, surface modification of ePTFE is sought after. In this study, polydopamine (PDA) was used to improve the hydrophilia and provide immobilization sites in ePTFE. Bivalirudin (BVLD), a direct thrombin inhibitor, was used to enhance the anti-thrombotic activity of ePTFE. The peptides derived from extracellular matrix proteins were used to elevate the bioactivity of ePTFE. The morphology, chemical composition, peptide modified strength, wettability, and hemocompatibility of modified ePTFE vascular grafts were investigated. Then, an endothelial cell proliferation assay was used to evaluate the best co-modification strategy of the ePTFE vascular graft in vitro. Since a large animal could relatively better mimic human physiology, we chose a porcine carotid artery replacement model in the current study. The results showed that the BVLD/REDV co-modified ePTFE vascular grafts had a satisfactory patency rate (66.7%) and a higher endothelial cell coverage ratio (70%) at 12 weeks after implantation. This may offer an opportunity to produce a multi-biofunctional ePTFE vascular graft, thereby yielding a potent product to meet the clinical needs.

Improving Chronic Diabetic Wound Healing through an Injectable and Self-Healing Hydrogel with Platelet-Rich Plasma Release.

Diabetic skin ulcer is one of the severe complications of diabetes mellitus, which has a high incidence and may cause death or disability. Platelet-rich plasma (PRP) is widely used in the treatment of diabetic wounds due to the effect of growth factors (GFs) derived from it. However, the relatively short half-life of GFs limits their applications in clinics. In addition, the presence of a large amount of proteases in the diabetic wound microenvironment results in the degradation of GFs, which further impedes angiogenesis and diabetic wound healing. In our study, we fabricated a self-healing and injectable hydrogel with a composite of chitosan, silk fibroin, and PRP (CBPGCTS-SF@PRP) for promoting diabetic wound healing. CBPGCTS-SF@PRP could protect PRP from enzymatic hydrolysis, release PRP sustainably, and enhance the chemotaxis of mesenchymal stem cells. The results showed that it could promote the proliferation of repair cells in vitro. Moreover, it could enhance wound healing by expediting collagen deposition, angiogenesis, and nerve repair in a type 2 diabetic rat model and a rat skin defect model. We hope that this study will offer a new treatment for diabetic nonhealing wounds in clinics.

A moisturizing chitosan-silk fibroin dressing with silver nanoparticles-adsorbed exosomes for repairing infected wounds.

Refractory wounds caused by microbial infection impede wound healing, vascular regeneration, nerve system repair and the regeneration of other skin appendages. In addition, large-area infected wounds cause the appearance of multidrug-resistant (MDR) bacterial strains, which pose a major challenge both in clinical and scientific research. Although many stem cell-derived exosomes have been demonstrated to promote skin repair and regeneration, exosomes are seldom applied in the treatment of infective wounds due to the lack of antimicrobial function. In this study, we fabricated an asymmetric wettable dressing with a composite of exosomes and silver nanoparticles (CTS-SF/SA/Ag-Exo dressing) for promoting angiogenesis, nerve repair and infected wound healing. The CTS-SF/SA/Ag-Exo dressing possesses multifunctional properties including broad-spectrum antimicrobial activity, promoting wound healing, retaining moisture and maintaining electrolyte balance. It can effectively inhibit the growth of bacterial and promote the proliferation of human fibroblasts in vitro. Moreover, the in vivo results show that the CTS-SF/SA/Ag-Exo dressing enhanced wound healing by accelerating collagen deposition, angiogenesis and nerve repair in a P. aeruginosa infected mouse skin wound defect model. We hope that this dressing will provide a solution for the repair of infected wounds for treatments in the clinic.

Ideal magnetic dipole resonances with metal-dielectric-metal hybridized nanodisks.

Magnetic resonances generated with nonmagnetic nanostructures have been widely used to design various functional nanophotonic devices, and it is important to realize pure magnetic dipole scattering for the unambiguous study of magnetic light-matter interactions. However, the magnetic responses often spectrally overlapping with other multipoles, which is the main obstacle to achieve ideal magnetic dipole resonances. This study proposes and theoretically demonstrates that an ideal magnetic dipole resonance can be excited with metal-dielectric-metal hybridized nanodisks. It is shown that although the generated magnetic dipole scattering around the bonding resonance of the hybridized nanodisk is spectrally overlapping with strong electric dipole and electric quadrupole contributions, an almost perfect current loop can be generated by adjusting the geometry parameters and the refractive index of the dielectric layer, thereby leading to the suppressing of the overlapping multipoles and the formation of an ideal magnetic dipole scattering. What's more important is that both electric and magnetic near-fields are enhanced simultaneously with the increasing of the refractive index of the dielectric layer, which makes the hybridized nanodisk a promising platform for enhanced magnetic light-matter interactions.