Efficient Organic Solar Cells Enabled by Simple Non-Fused Electron Donors with Low Synthetic Complexity.

Fused-ring electron donors boost the efficiency of organic solar cells (OSCs), but they suffer from high cost and low yield for their large synthetic complexity (SC > 30%). Herein, the authors develop a series of simple non-fused-ring electron donors, PF1 and PF2, which alternately consist of furan-3-carboxylate and 2,2'-bithiophene. Note that PF1 and PF2 present very small SC of 9.7% for their inexpensive raw materials, facile synthesis, and high synthetic yield. Compared to their all-thiophene-backbone counterpart PT-E, two new polymers feature larger conjugated plane, resulting in higher hole mobility for them, especially a value up to ≈10-4 cm2 V-1 ·s for PF2 with longer alkyl side chain. Meanwhile, PF1 and PF2 exhibit larger dielectric constant and deeper electronic energy level versus PT-E. Benefiting from the better physicochemical properties, the efficiencies of PF1- and PF2-based devices are improved by ≈16.7% and ≈71.3% relative to that PT-E-based devices, respectively. Furthermore, the optimized PF2-based devices with introducing PC71 BM as the third component deliver a higher efficiency of 12.40%. The work not only indicates that furan-3-carboxylate is a simple yet efficient building block for constructing non-fused-ring polymers but also provides a promising electron donor PF2 for the low-cost production of OSCs.

Vasorin-containing small extracellular vesicles retard intervertebral disc degeneration utilizing an injectable thermoresponsive delivery system.

Intervertebral disc degeneration (IDD) is the pathological reason of back pain and the therapeutic approaches are still unsatisfactory. Recently, mesenchymal stem cell-derived small extracellular vesicles (EVs) have emerged as the novel regenerative method for IDD. In this study, we intensively investigated the therapeutic mechanism of small EVs, and found that vasorin protein enriched in EVs promoted the proliferation and extracellular matrix anabolism of nucleus pulposus cells via the Notch1 signaling pathway. Then, we fabricated a thermoresponsive gel which composed of Pluronic F127 and decellularized extracellular matrix (FEC) for the delivery and sustained release of EVs. Besides, ex vivo and in vivo results showed that EVs embedded in FEC (EVs@FEC) ameliorate the disc degeneration efficiently and achieve better therapeutic effects than one-off EVs delivery. Collectively, these findings deepen the understanding of EVs mechanism in treating intervertebral disc degeneration, and also illustrate the promising capacity of sustained EVs release system for intervertebral disc regeneration.

Mesoporous Silica Carrier-Based Composites for Taste-Masking of Bitter Drug: Fabrication and Palatability Evaluation.

Palatability is one of the most critical characteristics of oral preparations. Therefore, the exploration of new techniques to mask the aversive taste of drugs is in continuous demand. In this study, we fabricated and characterized composites based on mesoporous silica (MPS) that consisted of MPS, a bitter drug, and release regulators. We conducted a palatability evaluation to assess the taste-masking efficacy of the composites. The composites were prepared using the dry impregnation method combined with hot-melt extrusion. Morphology and components distribution in composites were characterized by scanning electron microscopy, confocal laser scanning microscopy, X-ray photoelectron spectroscopy, powder flow properties evaluation, and nitrogen-sorption measurement. The results demonstrated that drugs mainly existed in the inner pore of composites, and release regulators existed in the inner pore and covered the composites' surface. Interactions among the composite components were studied using powder X-ray diffraction, differential scanning calorimetry, and Fourier transform infrared spectroscopy. The drug loaded into the composites was amorphous, and an intermolecular interaction occurred between the drug and the MPS. Taste-masked composites significantly reduced drug release levels under mouth conditions; thus, they prevented the interaction of the dissolved drug with taste receptors and improved palatability. An electronic tongue evaluation and a human taste panel assessment confirmed the better palatability of taste-masked composites. Moreover, the desired drug release behavior can be adjusted by choosing an appropriate release regulator, with stronger hydrophobicity of release regulators resulting in slower drug release. This work has provided new insights into taste-masking strategies for drugs with unpleasant tastes.

Zwitterionic Cellulose Nanofibrils with High Salt Sensitivity and Tolerance.

To improve the salt tolerance/sensitivity of cellulose nanofibrils (CNFs), zwitterionic cellulose nanofibrils (ZCNFs) were prepared from softwood bleached kraft pulp fibers via a sequential process of anionic modification with 2,2,6,6-tetramethylepiperidin-1-oxyl (TEMPO)-mediated oxidation, cationic modification with (2,3-epoxypropyl) trimethylammonium chloride (EPTMAC), and high-pressure homogenization. To produce ZCNFs with different contents of cation group, EPTMAC loadings of 0.15 to 1.15 g/g fiber were explored during cationization. The obtained ZCNFs were characterized by Fourier transform infrared spectroscopy (FT-IR), X-ray photoelectron spectra (XPS), thermogravimetric analysis (TGA), transmission electron microscopy (TEM), and rheological measurements. The salt tolerance of the ZCNFs was investigated by adding mixed salts into the ZCNF dispersions. The results demonstrated that the ZCNFs with both anionic and cationic charges were produced. Compared with the TEMPO-mediated oxidized cellulose nanofibrils (TOCNFs), the ZCNFs exhibited an excellent "salt-thickening" behavior under the studied salt concentrations (2-24% w/w). Moreover, increasing the content of the cation group increased the salt tolerance/sensitivity of ZCNFs. This work demonstrated that introducing cationic charges to the anionic charged TOCNFs imparts the produced ZCNFs with excellent salt sensitivity and tolerance, which could expand the application of nanocellulose in oil recovery or wastewater treatment.

Adjuvanticity Regulation by Biodegradable Polymeric Nano/microparticle Size.

Polymeric nano/microparticles as vaccine adjuvants have been researched in experimental and clinical studies. A more profound understanding of how the physicochemical properties regulate specific immune responses has become a vital requirement. Here we prepared poly(d,l-lactic-co-glycolic acid) (PLGA) nano/microparticles with uniform sizes (500 nm, 900 nm, 2.1 µm, and 4.9 µm), and the size effects on particle uptake, activation of macrophages, and antigen internalization were evaluated. Particle uptake kinetic studies demonstrated that 900 nm particles were the easiest to accumulate in cells. Moreover, they could induce macrophages to secrete NO and IL-1ß and facilitate antigen internalization. Furthermore, 900 nm particles, mixed with antigen, could exhibit superior adjuvanticity in both humoral and cellular immune responses in vivo, including offering the highest antibody protection, promoting the maximum secretion levels of IFN-γ and IL-4 than particles with other sizes. Overall, 900 nm might be the optimum choice for PLGA particle-based vaccine adjuvants especially for recombinant antigens. Understanding the effect of particle size on the adjuvanticity based immune responses might have important enlightenments for rational vaccine design and applications.

Immunopotentiator-Loaded Polymeric Microparticles as Robust Adjuvant to Improve Vaccine Efficacy.

PURPOSE: Adjuvants are required to ensure the efficacy of subunit vaccines. Incorporating molecular immunopotentiators within particles could overcome drawbacks of molecular adjuvants (such as solubility and toxicity), and improve adjuvanticity of particles, achieving stronger adjuvant activity. Aim of this study is to evaluate the adjuvanticity of immunopotentiator-loaded polymeric particles for subunit vaccine. METHODS: PLGA microparticles (PMPs) and imiquimod (TLR-7 ligand)-loaded PLGA microparticles (IPMPs) were prepared by SPG premix membrane emulsification. In vitro and in vivo studies were performed to their adjuvant activity, using ovalbumin and H5N1 influenza split vaccine as antigens. RESULTS: Incorporating imiquimod into microparticles significantly improved the efficacy of PLGA microparticles in activating BMDCs and pMΦs, and antigen uptake by pMΦs was also promoted. IPMPs showed stronger adjuvanticity to augment OVA-specific immune responses than PMPs. IgG subclass profiles and cytokine secretion levels by splenocytes indicated that IPMPs elicited more Th1-polarized immune response, compared to PMPs. In vivo study using H5N1 influenza split vaccine as antigen also confirmed the effects of IPMPs on antigen-specific cellular immunity. CONCLUSIONS: Considering adjuvanticity and safety profiles (PLGA and IMQ, both approved by FDA), we conclude that IMQ-loaded PLGA microparticles are promising robust adjuvant for subunit vaccines.

Enhanced humoral and cell-mediated immune responses generated by cationic polymer-coated PLA microspheres with adsorbed HBsAg.

Surface-engineered particulate delivery systems for vaccine administration have been widely investigated in experimental and clinical studies. However, little is known about charge-coated microspheres as potential recombinant subunit protein antigen delivery systems in terms of adsorption and related immune responses. In the present study, cationic polymers, including chitosan (CS), chitosan chloride (CSC), and polyethylenimine (PEI), were used to coat PLA microspheres to build positively charged surfaces. Antigen adsorption capacity was enhanced with increased surface charge of coated microspheres. In macrophages, HBsAg adsorbed on the surface of cationic microspheres specifically enhanced antigen uptake and augmented CD86, MHC I, and MHC II expression and IL-1ß, IL-6, TNF-α, and IL-12 release. Antigens were more likely to localize independent of lysosomes after phagocytosis in antigen-attached cationic microsphere formulations. After intraperitoneal immunization, cationic microsphere-based vaccine formulations generated a rapid and efficient humoral immune response and cytokine release as compared with aluminum-adsorbed vaccine and free antigens in vivo. Moreover, microspheres coated with cationic polymers with relatively high positive charges and higher antigen adsorption exhibited strong stimulation of the Th1 response. In conclusion, PLA microspheres coated with cationic polymers may be a potential recombinant antigen delivery system to induce strong cell and humoral immune responses.

Comparison of PLA microparticles and alum as adjuvants for H5N1 influenza split vaccine: adjuvanticity evaluation and preliminary action mode analysis.

PURPOSE: To compare the adjuvanticity of polymeric particles (new-generation adjuvant) and alum (the traditional and FDA-approved adjuvant) for H5N1 influenza split vaccine, and to investigate respective action mode. METHODS: Vaccine formulations were prepared by incubating lyophilized poly(lactic acid) (PLA) microparticles or alum within antigen solution. Antigen-specific immune responses in mice were evaluated using ELISA, ELISpot, and flow cytometry assay. Adjuvants' action modes were investigated by determining antigen persistence at injection sites, local inflammation response, antigen transport into draining lymph node, and activation of DCs in secondary lymphoid organs (SLOs). RESULTS: Alum promoted antigen-specific humoral immune response. PLA microparticles augmented both humoral immune response and cell-mediated-immunity which might enhance cross-protection of influenza vaccine. With regard to action mode, alum adjuvant functions by improving antigen persistence at injection sites, inducing severe local inflammation, slightly improving antigen transport into draining lymph nodes, and improving the expression of MHC II on DCs in SLOs. PLA microparticles function by slightly improving antigen transport into draining lymph nodes, and promoting the expression of both MHC molecules and co-stimulatory molecules on DCs in SLOs. CONCLUSIONS: Considering the adjuvanticity and side effects (local inflammation) of both adjuvants, we conclude that PLA microparticles are promising alternative adjuvant for H5N1 influenza split vaccine.

Sustainable assessment and synergism of ceramic powder and steel slag in iron ore tailings-based concrete.

Solid waste management is a critical issue worldwide. Effectively utilizing these solid waste resources presents a viable solution. This study focuses on Iron ore tailings (IOTs), a solid waste generated during iron ore processing, which can be used as supplementary cementitious materials (SCMs) but have low reactivity, hindering their large-scale application in concrete production. To address this, ternary SCMs were prepared using ceramic powder (CP) and steel slag (SS) to enhance the performance of concrete incorporating IOTs. The study found that the synergistic effect of CP and SS significantly improved the compressive strength of concrete, with a notable increase of up to 21% compared to concrete with IOTs alone. Mercury intrusion porosimetry (MIP) and backscattering electron (BSE) analyses revealed that the ternary SCMs significantly optimized the characteristics of the interfacial transition zone (ITZ), which in turn enhanced the compressive properties of the concrete. This contributed to maintaining the structural integrity of the concrete, even amidst variations in the pore structure. Importantly, the incorporation of ternary SCMs led to a 23% reduction in carbon emissions, from 400.01 kg CO2/m3 to 307.48 kg CO2/m3, and elevated eco-strength efficiency from 0.1 to 0.14. The study highlights the role of multi-material synergy in developing composite SCMs systems, fostering the sustainable advancement of green building materials.

Silver Mineralized Protein Hydrogel with Intrinsic Cell Proliferation Promotion and Broad-Spectrum Antimicrobial Properties for Accelerated Infected Wound Healing.

The presence of multidrug-resistant bacteria has challenged the clinical treatment of bacterial infection. There is a real need for the development of novel biocompatible materials with broad-spectrum antimicrobial activities. Antimicrobial hydrogels show great potential in infected wound healing but are still being challenged. Herein, broad-spectrum antibacterial and mechanically tunable amyloid-based hydrogels based on self-assembly and local mineralization of silver nanoparticles are reported. The mineralized hydrogels are biocompatible and have the advantages of sustained release of silver, prolonged antimicrobial effect, and improved adhesion capacity. Moreover, the mineralized hydrogels display a significant antimicrobial effect against both Gram-positive and Gram-negative bacteria in cells and mice by inducing membrane damage and reactive oxygen species toxicity in bacteria. In addition, the mineralized hydrogels can rapidly accelerate wound healing by the synergy between their antibacterial activity and intrinsic improvement for cell proliferation and migration. This study provides a modular approach to developing a multifunctional protein hydrogel platform based on biomolecule-coordinated self-assembly for a wide range of biomedical applications.

Transparent and Stretchable Graphene Electrode by Intercalation Doping for Epidermal Electrophysiology.

Epidermal electronics is regarded as the next-generation technology, and graphene is a promising electrode, which is a key building block of such devices. However, graphene has a tendency to crack at small strains with a rapidly increased resistance upon stretching. Here, to enable graphene applicable in epidermal electronics, we designed a novel graphene structure that is molybdenum chloride (MoCl5)-intercalated few-layer graphene (Mo-FLG) fabricated in a confined environment. In the case of bilayer graphene (BLG), MoCl5-intercalated bilayer graphene (Mo-BLG) exhibited a low sheet resistance of 40 Ω/square (sq) at a transmittance of 80%. Due to the self-barrier doping effect, the sheet resistance increased to only 60 Ω/sq after exposing to the atmosphere over 1 month. Transferred onto elastomer substrates, Mo-BLG can work as an electrode up to 80% strain and maintain a high conductivity that is durable over 2000 cycles at 30% strain. This mechano-electrostability is attributed to the special intercalated structure where the intercalated dopants act as lubricants to weaken the layer-layer interaction and allow a certain degree of sliding, as well as electrical crack-connectors to bridge the cracked domains at a high strain. Mo-BLG can be applied as epidermal electrodes to monitor electrophysiological signals such as electrocardiogram (ECG), electrooculogram (EOG), electroencephalography (EEG), and surface electromyogram (sEMG) with high signal-to-noise ratios (SNRs) comparable to commercial Ag/AgCl electrode. This is the first demonstration of epidermal electrodes based on intercalation-doped graphene applied in health monitoring, shedding light on the future development of graphene-based epidermal electronics.

A versatile CeO2/Co3O4 coated mesh for food wastewater treatment: Simultaneous oil removal and UV catalysis of food additives.

Food waste water is one of the most urgent environmental problems for the close connection between food and our daily life. Herein, we use a simple hydrothermal method to prepare a highly efficient catalyst-CeO2/Co3O4 compound on the stainless steel mesh, aiming for food waste water treatment. Possessing the superhydrophilic property and catalytic ability under ultraviolet light, CeO2/Co3O4 coated mesh has successfully processed three representative contaminants in food wastewater, which are soybean oil (food oil), AR (food dye) and VA (food flavor) simultaneously with an one-step filtration. Besides, the mesh is stable in a wide pH range and performs well in reusability. Therefore, such a multifunctional material with simple preparation method, high processing efficiency and facile operation shows a promising prospect for practical production and application for food wastewater treatment.

A Solvothermal Route Decorated on Different Substrates: Controllable Separation of an Oil/Water Mixture to a Stabilized Nanoscale Emulsion.

A facile solvothermal route is developed to fabricate polydivinylbenzene (PDVB) and decorate the polymer onto porous substrates. "Controllable" separation can be realized by selecting substrates with different pore sizes. The PDVB-modified mesh shows superhydrophobicity/superoleophilicity, and can be used for oil/seawater mixture separation, while the PDVB-modified membrane exhibits high hydrophobicity/superoleophilicity, and is able to separate surfactant stabilized nanoscale water-in-oil emulsions.

pH-Responsive Poly(D,L-lactic-co-glycolic acid) Nanoparticles with Rapid Antigen Release Behavior Promote Immune Response.

In the quest to treat intracellular infectious diseases and virus infection, nanoparticles (NPs) have been considered to be efficient tools for inducing potent immune responses, specifically cellular immunity. Antigen processing and presenting by antigen presenting cells (APCs) could influence immune response, especially the priming of T-cell-mediated cellular immunity. Here, we fabricated pH-responsive poly(D,L-lactic-co-glycolic acid) (PLGA) NPs with rapid antigen intracellular release behavior in APCs. The NPs, which had thin shells and large inner space, contain ammonium bicarbonate (NH4HCO3), which could regulate release in endosomes and lysosomes, acting as an antigen release promoter in dendritic cells (DCs), and were coencapsulated with antigen (ovalbumin, OVA). Hydrogen ions (H(+)) in DC endosomes and lysosomes (pH ∼5.0 and 6.5) could react with NH4HCO3 to generate NH3 and CO2, which broke NPs and released antigens. After uptake by DCs, antigens encapsulated in pH-responsive PLGA NPs could escape from lysosomes into the cytoplasm and be cross-presented. Moreover, the NPs induced up-regulation of co-stimulatory molecules and stimulated cytokine production. Mouse immunization with pH-responsive PLGA NPs induced greater lymphocyte activation, more antigen-specific CD8(+) T cells, stronger cytotoxic capacity (IFN-γ and granzyme B), enhanced antigen-specific IgG antibodies, and higher serum IgG2a/IgG1, indicating cellular immunity. The NPs also improved generation of memory T cells to protect against reinfection. Thus, pH-responsive PLGA NPs, which induced strong cellular immune responses and offered antibody protection, could be potentially useful as effective vaccine delivery and adjuvant systems for the therapy of intracellular infectious diseases and virus infection.

Polycation-decorated PLA microspheres induce robust immune responses via commonly used parenteral administration routes.

Recombinant viral subunit-based vaccines have gained increasing attention due to their enhanced safety over the classic live-attenuated or inactivated vaccines. The low immunogenicity of the subunit antigen alone, however, requires the addition of an adjuvant to induce immunity. Particulate-based delivery systems have great potential for developing new vaccine adjuvants, compared to traditional aluminum-based saline adjuvants. The physicochemical properties of particulate vaccines have been extensively investigated; however, few studies have focused on how the administration route of various adjuvant-antigen combinations impacts the efficacy of the immune response. Here, for the first time, the viral Hepatitis B surface antigen (HBsAg) was combined with aluminum-based or cationic-microsphere (MP) based adjuvants to investigate the characteristics of immune responses elicited after immunization via the subcutaneous, intramuscular, or intraperitoneal routes respectively. In vitro, the MP-based vaccine significantly increased dendritic cell (DC) activation with up-regulated CD40 and CD80 expression and IL-12 production compared to alum-based vaccine. After immunization, both MP and alum-based vaccines produced increased IgG titers in mice. The administration route of these vaccines did influenced immune responses. The MP-based vaccine delivered via the intramuscular route yielded the highest levels of the IgG2a isotype. The alum-based vaccine, delivered via the same route, produced an IgG1-dominated humoral immune response. Moreover, subcutaneous and intramuscular immunizations with MP-based vaccine augmented Granzyme B, Th1-type cytokines (IL-2, IL-12, and IFN-γ), and Th2 cytokine IL-4 secretions. These results demonstrate that MP-based vaccines have the capacity to induce higher cellular and humoral immune response especially via an intramuscular administration route than an alum-based vaccine.

Immune responses to vaccines involving a combined antigen-nanoparticle mixture and nanoparticle-encapsulated antigen formulation.

Many physicochemical characteristics significantly influence the adjuvant effect of micro/nanoparticles; one critical factor is the kinetics of antigen exposure to the immune system by particle-adjuvanted vaccines. Here, we investigated how various antigen-nanoparticle formulations impacted antigen exposure to the immune system and the resultant antigen-specific immune responses. We formulated antigen with poly(lactic-co-glycolic acid) (PLGA) nanoparticles by encapsulating antigen within nanoparticles or by simply mixing soluble antigen with the nanoparticles. Our results indicated that the combined formulation (composed of antigen encapsulated in nanoparticles and antigen mixed with nanoparticles) induced more powerful antigen-specific immune responses than each single-component formulation. Mice immunized with the combined vaccine formulation displayed enhanced induction of antigen-specific IgG antibodies with high avidity, increased cytokine secretion by splenocytes, and improved generation of memory T cell. Enhanced immune responses elicited by the combined vaccine formulation might be attributed to the antigen-depot effect at the injection site, effective provision of both adequate initial antigen exposure and long-term antigen persistence, and efficient induction of dendritic cell (DC) activation and follicular helper T cell differentiation in draining lymph nodes. Understanding the effect of antigen-nanoparticle formulations on the resultant immune responses might have significant implications for rational vaccine design.

Microspheres and microcapsules for protein delivery: strategies of drug activity retention.

With the recent progress in biotechnology and genetic engineering, a variety of proteins have formed a very important class of therapeutic agents. However, most proteins have short half-lives in vivo requiring multiple treatments to provide efficacy. In order to overcome this limitation, sustained release systems as hydrophilic microspheres and hydrophobic microcapsules have received extensive attention in recent years. As therapeutic proteins delivery systems, it is necessary to maintain protein bioactivity during microspheres or microcapsules formation as much as possible. This paper reviews different influencing factors that are closely involved in protein denaturation during the preparation of hydrophilic polymer microspheres and hydrophobic polymer microcapsules. The various strategies usually employed for overcoming these obstacles are described in detail. Both processing and formulation parameters can be modified for improving protein stability. The maximum or full protein stability retention within the microspheres or microcapsules might be achieved by individual or combined optimized strategies. In addition, the common techniques for proteins stability determination are also briefly reviewed.

[Removal of CO2 from simulated flue gas of power plants by membrane-based gas absorption processes].

Three typical absorbents such as aqueous of aminoacetic acid potassium (AAAP), monoethanolamine (MEA) and methyldiethanolamine(MDEA) are selected to investigate the performance of CO2 separation from flue gas via membrane contactors made of hydrophobic hollow fiber polypropylene porous membrane. Impacts of absorbents, concentrations and flow rates of feeding gas and absorbent solution, cyclic loading of CO2 on the removal rate and the mass transfer velocity of CO2 are discussed. The results demonstrate that the mass transfer velocity was 7.1 mol x (m2 x s)(-1) for 1 mol x L(-1) MEA with flow rate of 0.1 m x s(-1) and flue gas with that of 0.211 m x s(-1). For 1 mol L(-1) AAAP with flow rate of 0.05 m x s(-1) and flue gas of 0.211 m x s(-1), CO2 removal rate (eta) was 93.2 % and eta was 98% for 4 mol x L(-1) AAAP under the same conditions. AAAP being absorbent, eta was higher than 90% in a wider range of concentrations of CO2. It indicates that membrane-based absorption process is a widely-applied and promising way of CO2 removal from flue gas of power plants, which not only appropriates for CO2 removal of flue gas of widely-used PF and NGCC, but also for that of flue gas of IGCC can be utilized widely in future.