Hyperbranched Polymer Induced Antibacterial Tree-Like Nanofibrous Membrane for High Effective Air Filtration.

The air filtration materials with high efficiency, low resistance, and extra antibacterial property are crucial for personal health protection. Herein, a tree-like polyvinylidene fluoride (PVDF) nanofibrous membrane with hierarchical structure (trunk fiber of 447 nm, branched fiber of 24.7 nm) and high filtration capacity is demonstrated. Specifically, 2-hydroxypropyl trimethyl ammonium chloride terminated hyperbranched polymer (HBP-HTC) with near-spherical three-dimensional molecular structure and adjustable terminal positive groups is synthesized as an additive for PVDF electrospinning to enhance the jet splitting and promote the formation of branched ultrafine nanofibers, achieving a coverage rate of branched nanofibers over 90% that is superior than small molecular quaternary ammonium salts. The branched nanofibers network enhances mechanical properties and filtration efficiency (99.995% for 0.26 µm sodium chloride particles) of the PVDF/HBP-HTC membrane, which demonstrates reduced pressure drop (122.4 Pa) and a quality factor up to 0.083 Pa-1 on a 40 µm-thick sample. More importantly, the numerous quaternary ammonium salt groups of HBP-HTC deliver excellent antibacterial properties to the PVDF membranes. Bacterial inhibitive rate of 99.9% against both S. aureus and E. coli is demonstrated in a membrane with 3.0 wt% HBP-HTC. This work provides a new strategy for development of high-efficiency and antibacterial protection products.

Dissolving Microneedle Arrays as a Hepatitis B Vaccine Delivery System Adjuvanted by APC-Targeted Poly (Lactic-co-Glycolic Acid) (PLGA) Nanoparticles.

The objective of this study is to develop a new hepatitis B surface antigen (HBsAg) delivery system by coating soluble microneedle arrays with mannose-modified PLGA nanoparticles (MNPs). MNPs of different sizes were synthesized. The effects these nanoparticles on the maturation of dendritic cells were studied by flow cytometry. HBsAg-containing MNPs (HBsAg/MNPs) of the appropriate sizes were coated into water-soluble microneedle arrays. The in vitro characteristics of microneedles arrays and the immune responses after subcutaneous administration in mice were studied. The results showed that PLGA nanoparticles with an average size of about 800 nm showed the most significant effects in stimulating the maturation of dendritic cells. In the water-soluble microneedle array, the targeted PLGA nanoparticles containing HBsAg were distributed discretely with a maximum distribution height of about 280 µm with a drug load of 0.98 ± 0.05 µg/mg. The drug-containing microneedle arrays exhibited excellent mechanical properties and improved biosafety. The results of immune responses in vivo showed that the subcutaneous administration of the microneedle arrays induced the proliferation of splenocyte, secreted specific IL-12 and IFN-γ, and promote the production of IgG in mice. This study verifies the feasibility of soluble composited microneedles administration in hepatitis B immunization, and provides new ideas for the development and application of non-injectable vaccine delivery systems.

Therapeutic effects of cationic liposomes on lupus-prone MRL/lpr mice are mediated via inhibition of TLR4-triggered B-cell activation.

We previously reported that co-delivery of dihydroartemisinin and high mobility group box 1 (HMGB1) siRNAs, using cell penetrating peptide (TAT)-modified cationic liposomes (TAT-CLs-DHA/siRNA), resulted in promising activity for the treatment of inflammatory disease through TLR4 signaling pathway. In the current study, we further investigated the therapeutic effects of TAT-CLs-DHA/siRNA on lupus-prone MRL/lpr mice and explored its effects on B cell responses. In vitro, we found that TAT-CLs-DHA/siRNA suppressed the proliferation and activation of B cells through the TLR4 signaling pathway. Following parenteral administration every 4 days, TAT-CLs-DHA/siRNA significantly reduced proteinuria, glomerulonephritis, serum anti-dsDNA antibody and secretion of interleukin (IL)-6, IL-10, IL-17 and IL-21. Moreover, Western blotting showed that TAT-CLs-DHA/siRNA modulated the B-cell intrinsic pathway by downregulating expression of HMGB1, TLR4, MyD88 and NF-κB. This co-delivery system thus represents a promising treatment option for lupus nephritis, and also highlights a novel target of lupus treatment through B cell TLR4 signal pathway.

Chimeric cellulase matrix for investigating intramolecular synergism between non-hydrolytic disruptive functions of carbohydrate-binding modules and catalytic hydrolysis.

The conversion of renewable cellulosic biomass is of considerable interest for the production of biofuels and materials. The bottleneck in the efficient conversion is the compactness and resistance of crystalline cellulose. Carbohydrate-binding modules (CBMs), which disrupt crystalline cellulose via non-hydrolytic mechanisms, are expected to overcome this bottleneck. However, the lack of convenient methods for quantitative analysis of the disruptive functions of CBMs have hindered systematic studies and molecular modifications. Here we established a practical and systematic platform for quantifying and comparing the non-hydrolytic disruptive activities of CBMs via the synergism of CBMs and a catalytic module within designed chimeric cellulase molecules. Bioinformatics and computational biology were also used to provide a deeper understanding. A convenient vector was constructed to serve as a cellulase matrix into which heterologous CBM sequences can be easily inserted. The resulting chimeric cellulases were suitable for studying disruptive functions, and their activities quantitatively reflected the disruptive functions of CBMs on crystalline cellulose. In addition, this cellulase matrix can be used to construct novel chimeric cellulases with high hydrolytic activities toward crystalline cellulose.

Quantitative investigation of non-hydrolytic disruptive activity on crystalline cellulose and application to recombinant swollenin.

For the efficient degradation and bioconversion of cellulosic biomass, it is important to efficiently disrupt and convert crystalline regions of cellulose into easily hydrolyzable regions than to simply hydrolyze cellulose. Expansin-like proteins such as swollenins have disruptive functions on lignocellulose, including crystalline cellulose, via non-hydrolytic mechanisms. In this work, we produced the swollenin from Trichoderma asperellum in Escherichia coli. The recombinant protein was then refolded into the bioactive form with simultaneous purification via a novel cellulose-assisted process. We devised a novel, simple, and efficient method to quantitatively determine the non-hydrolytic disruptive activity of swollenin on crystalline cellulose. This method is based on the synergism of the swollenin and the endoglucanase FnCel5A from Fervidobacterium nodosum. The change from crystalline regions into easily hydrolyzable forms, due to non-hydrolytic disruption, might be slight and not easily be observed. However, disrupted regions of cellulose could be hydrolyzed by FnCel5A, and reducing sugars were formed by the synergism. The disruptive function of the swollenin was quantitatively characterized by measuring the release of reducing sugars. These methods and processes will be useful for further research on non-hydrolytic disruptive bioactivities and provide novel approaches for the efficient and economical bioconversion of cellulosic biomass.

A narrow-band subwavelength plasmonic waveguide filter with asymmetrical multiple-teeth-shaped structure.

Characteristics of a multiple-teeth-shaped plasmonic filter are analyzed. As an extension of this structure, an asymmetrical multiple-teeth-shaped structure is proposed and numerically simulated by using the finite difference time domain method with perfectly matched layer absorbing boundary condition. It is found that the asymmetrical structure can realize the function of a narrow-passband filter. The central wavelength of the passband linearly increases with the simultaneous increasing of d(1) and d(2).

Co-Delivery Of Dihydroartemisinin And HMGB1 siRNA By TAT-Modified Cationic Liposomes Through The TLR4 Signaling Pathway For Treatment Of Lupus Nephritis.

BACKGROUND AND PURPOSE: Systemic lupus erythematous (SLE) is an autoimmune disease caused by many factors. Lupus nephritis (LN) is a common complication of SLE and represents a major cause of morbidity and mortality. Previous studies have shown the advantages of multi-targeted therapy for LN and that TLR4 signaling is a target of anti-LN drugs. High-mobility group box 1 (HMGB1), a nuclear protein with a proinflammatory cytokine activity, binds specifically to TLR4 to induce inflammation. We aimed to develop PEGylated TAT peptide-cationic liposomes (TAT-CLs) to deliver anti-HMGB1 siRNA and dihydroartemisinin (DHA) to increase LN therapeutic efficiency and explore their treatment mechanism. METHODS: We constructed the TAT-CLs-DHA/siRNA delivery system using the thin film hydration method. The uptake and localization of Cy3-labeled siRNA were detected by confocal microscopy and flow cytometry. MTT assays were used to detect glomerular mesangial cell proliferation. Real-time PCR, Western blot analysis, and ELISA evaluated the anti-inflammatory mechanism of TAT-CLs-DHA/siRNA. RESULTS: We constructed the TAT-CLs-DHA/siRNA delivery system measuring approximately 140 nm with superior storage and serum stabilities. In vitro, it showed significantly greater uptake compared with unmodified liposomes and significant inhibition of glomerular mesangial cell proliferation. TAT-CLs-DHA/siRNA inhibited NF-κB activation in a concentration-dependent manner. Real-time PCR and Western blot analysis showed that TAT-CLs-DHA/siRNA downregulated expression of HMGB1 mRNA and protein. TAT-CLs-DHA/siRNA markedly diminished Toll-like receptor 4 (TLR4) expression and subsequent activation of MyD88, IRAK4, and NF-κB. CONCLUSION: TAT-CLs-DHA/siRNA may have the potential for treatment of inflammatory diseases such as LN mediated by the TLR4 signaling pathway.

Targeting lipid metabolism to overcome EMT-associated drug resistance via integrin ß3/FAK pathway and tumor-associated macrophage repolarization using legumain-activatable delivery.

Epithelial-mesenchymal transition (EMT) is closely associated with the development of drug resistance. Lipid metabolism plays an important role in EMT. This work was to study the cholesterol-lowering drug simvastatin for reversing EMT-associated resistance to chemotherapy via lipid metabolism. METHODS: The combination of simvastatin and paclitaxel was used to overcome the EMT-associated drug resistance. For dual-action on both cancer cells and tumor-associated macrophages (TAM), the tumor microenvironment-activatable multifunctional liposomes were developed for drug codelivery. The liposomes were modified with a hairpin-structured, activatable cell-penetrating peptide that is specifically responsive to the tumor-associated protease legumain. RESULTS: It was revealed simvastatin can disrupt lipid rafts (cholesterol-rich domains) and suppress integrin-ß3 and focal adhesion formation, thus inhibiting FAK signaling pathway and re-sensitizing the drug-resistant cancer cells to paclitaxel. Furthermore, simvastatin was able to re-polarize tumor-associated macrophages (TAM), promoting M2-to-M1 phenotype switch via cholesterol-associated LXR/ABCA1 regulation. The repolarization increased TNF-α, but attenuated TGF-ß, which, in turn, remodeled the tumor microenvironment and suppressed EMT. The liposomal formulation achieved enhanced treatment efficacy. CONCLUSION: This study provides a promising simvastatin-based nanomedicine strategy targeting cholesterol metabolism to reverse EMT and repolarize TAM to treat drug-resistant cancer. The elucidation of the molecular pathways (cholesterol/lipid raft/integrin ß3/FAK and cholesterol-associated LXR/ABCA1 regulation) for anti-EMT and the new application of simvastatin should be of clinical significance.

Novel self-assembled tacrolimus nanoparticles cross-linking thermosensitive hydrogels for local rheumatoid arthritis therapy.

The aim was to explore the potential application of novel self-assembled nanoparticles cross-linking thermosensitive hydrogels composed of polyvinyl caprolactam-polyvinyl acetate-polyethylene glycol (Soluplus) and tacrolimus (FK-506) for local therapy of rheumatoid arthritis (RA). The sol-gel transition temperature (Tsol-gel), gelation time, rheological behaviors, in vitro release, in vivo gelation and retention, and therapeutic efficacy against adjuvant-induced arthritis (AIA) rats were compared between the Soluplus hydrogels and widely studied poloxamer 407 (P407) delivery systems. In sol, the spherical and uniform FK506 loaded Soluplus nanoparticles (Soluplus-SNPs) were self-assembled with encapsulation efficiency of 99.5±1.5% and particle size of 73.9±2.9nm. The decreased Tsol-gel of Soluplus-SNPs hydrogels was associated with the addition of salts, elevation of pH and ionic strength. The optimal Tsol-gel of Soluplus-SNPs with concentrations of 10%-30% in phosphate buffer (50mM, pH 7.4) was from 37.4±0.1°C to 32.8±0.3°C and the gelation time was not greater than 2min. Soluplus-SNPs gelling systems showed lower viscosity and wider range concentrations in sol state at 25°C and stronger gel strength at 37°C than P407, which resulting in longer sustained release of FK506 but without burst-release in vitro, and longer retention time in the local injection site in vivo. The therapeutic efficacy to treat AIA rats was significantly enhanced from d10 to d17 after a single dose of FK506 loaded in 10% and 20% Soluplus-SNPs hydrogels. In conclusion, Soluplus-SNPs hydrogel is a potential sustainable delivery system for FK506 to treat RA locally.

Optimization of a cationic liposome-based gene delivery system for the application of miR-145 in anticancer therapeutics.

In order to improve the delivery efficiency of microRNA (miRNA or miR)-145, the present study examined several factors which may affect cationic liposome (CL)-based transfection, including the hydration medium used for the preparation of liposomes, the quantity of the plasmid, the molar ratio of N-[1-(2,3-dioleoyloxy)propyl]-N,N,N-trimethylammonium chloride (DOTAP)/cholesterol (chol), or DOTAP/chol, and the weight ratio of DOTAP/DNA. In order to enhance the transfection efficiency, protamine was selected as a DNA-condensing agent to form liposome­protamine­DNA (LPD) ternary complexes. An agarose gel retardation assay was used to examine the DNA binding affinity of the CLs. Following transfection, GFP fluorescence images were captured and flow cytometry was performed to determine the transfection efficiency. Furthermore, an MTT assay was performed to determine the cytotoxicity of the liposome complexes. The final optimal conditions were as follows: 5% glucose as the hydration medium, a molar ratio of DOTAP/chol at 3:1 for the preparation of CLs, a weight ratio of DOTAP/protamine/DNA of 3:0.5:1, with 8 µg plasmid added for the preparation of the LPD complexes. In vitro, the LPD complexes exhibited an enhanced transfection efficiency and low cytotoxicity, which indicated that the presented LPD vector enhanced the transfection efficiency of the CLs. The HepG2 cells were found to have the lowest expression levels of miR­145 out of the cell lines tested (A549, BGC-823, HepG2, HeLa, LoVo and MCF-7). Following the transient transfection of the HepG2 cells with miR­145, the results revealed that the overexpression of miR­145 inhibited the proliferation of the HepG2 cells and downregulated the expression of cyclin-dependent kinase 6 (CDK6), cyclinD1, c-myc, and Sp1 transcription factor (Sp1). In conclusion, in this study, we optimized a liposome­based delivery system for the efficient delivery of miR­145 into cancer cells. This may provide a foundation for further research into the use of miR­145 in anticancer therapeutics.