Crosslinked Silk Fibroin/Gelatin/Hyaluronan Blends as Scaffolds for Cell-Based Tissue Engineering

3D porous scaffolds fabricated from binary and ternary blends of silk fibroin (SF), gelatin (G), and hyaluronan (HA) and crosslinked by the carbodiimide coupling reaction were developed. Water-stable scaffolds can be obtained after crosslinking, and the SFG and SFGHA samples were stable in cell culture medium up to 10 days. The presence of HA in the scaffolds with appropriate crosslinking conditions greatly enhanced the swellability. The microarchitecture of the freeze-dried scaffolds showed high porosity and interconnectivity. In particular, the pore size was significantly larger with an addition of HA. Biological activities of NIH/3T3 fibroblasts seeded on SFG and SFGHA scaffolds revealed that both scaffolds were able to support cell adhesion and proliferation of a 7-day culture. Furthermore, cell penetration into the scaffolds can be observed due to the interconnected porous structure of the scaffolds and the presence of bioactive materials which could attract the cells and support cell functions. The higher cell number was noticed in the SFGHA samples, possibly due to the HA component and the larger pore size which could improve the microenvironment for fibroblast adhesion, proliferation, and motility. The developed scaffolds from ternary blends showed potential in their application as 3D cell culture substrates in fibroblast-based tissue engineering.     

Ternary composite films of natural rubber,cellulose microfiber,and carboxymethyl cellulose for excellent mechanical properties,biodegradability and chemical resistance

Cellulose - Fast and facile preparation of composite films containing natural rubber and Eucalyptus cellulose microfiber was achieved by the addition of carboxyl methyl cellulose to yield advantage...     

Cytotoxic tropolones from the fungus Nemania sp. BCC 30850

Twelve new compounds, including nine tropolones, nemanolones A?I (1–9), three 7-isochromenones, nemanecins A?C (10–12), and a new naturally isolated 4-isochromanone (13), along with two known compounds, 7,8-dihydroxy-3-methyl isochroman-4-one (XJP), and chaetoquadrin F, were isolated from culture broth of the fungus Nemania sp. BCC 30850. Structures of these compounds were elucidated by NMR and MS spectroscopic analyses. Nemanolones exhibited cytotoxic activities and two of them, compounds 1 and 2, also showed antibacterial activity against Bacillus cereus and antifungal activity against Candida albicans.     

Hydrolyzed Flavonoids from Cyrtosperma johnstonii with Superior Antioxidant,Antiproliferative, and Anti-Inflammatory Potential for Cancer Prevention

Cyrtosperma johnstonii is one of the most interesting traditional medicines for cancer treatment. This study aimed to compare and combine the biological activities related to cancer prevention of the flavonoid glycosides rutin (RT) and isorhamnetin-3-o-rutinoside (IRR) and their hydrolysis products quercetin (QT) and isorhamnetin (IR) from C. johnstonii extract. ABTS and MTT assays were used to determine antioxidant activity and cytotoxicity against various cancer cells, as well as normal cells. Anti-inflammatory activities were measured by ELISA. The results showed that the antioxidant activities of the compounds decreased in the order of QT > IR > RT > IRR, while most leukemia cell lines were sensitive to QT and IR with low toxicity towards PBMCs. The reduction of IL-6 and IL-10 secretion by QT and IR was higher than that induced by RT and IRR. The combination of hydrolysis products (QT and IR) possessed a strong synergism in antioxidant, antiproliferative and anti-inflammatory effects, whereas the combination of flavonoid glycosides and their hydrolysis products revealed antagonism. These results suggest that the potential of the combination of hydrolyzed flavonoids from C. johnstonii can be considered as natural compounds for the prevention of cancer.     

Carbazole dendronised triphenylamines as solution processed high Tg amorphous hole-transporting materials for organic electroluminescent devices

Carbazole dendrimers up to 4th generation were synthesized. They showed significantly high T(g), amorphous and stable electrochemical properties, and great potential as solution processed hole-transporting materials for OLEDs. Alq3-based green devices exhibited high luminance efficiency and CIE coordinates of 4.45 cd A(-1) and (0.29, 0.53), respectively.     

Coumarin-cored carbazole dendrimers as solution-processed non-doped green emitters for electroluminescent devices

A series of green-emitting thiophenyl coumarin-cored carbazole dendrimers containing carbazole dendrons up to the third generation as substituent were synthesized and characterization. Their optical, thermal, electrochemical, and electroluminescent properties as non-doped solution-processed light-emitters for OLEDs were investigated. By incorporating carbazole dendrons in the molecule, we are able to reduce the crystallization and retain the high emissive ability of a planar thiophenyl coumarin fluorescent core in the solid state as well as improve the thermal stability of the material. These dendrimers showed a bright-green fluorescence and can form morphologically stable amorphous thin films with glass-transition temperatures as high as 285 °C. Simple structured solution-processed OLEDs using these materials as hole-transporting non-doped emitters and BCP as a buffer layer emit a stable green electroluminescence (λ_EL=502–526 nm) with high luminance efficiencies (up to 7.92 cd/A at 7.39 mA/cm²) and high green color purity (CIE=0.26, 0.62, which are close to the pure green color).     

meso-Multi(iodophenyl) porphyrins: synthesis, isolation, and identification

We report on a simple method for identification of a series of six meso-substituted porphyrins by ¹H NMR spectroscopy. The meso-substituted porphyrins are synthesized by a simple mixed-aldehyde condensation approach [3,5-di-tert-butylstyrylbenzaldehyde (A) and 4-iodobenzaldehyde (B)] to give the two parent porphyrins (A₄, B₄) and four hybrid porphyrins (A₃B, cis-A₂B₂, trans-A₂B₂, AB₃) which are isolated and characterized.     

Blennolide derivatives from the soil-derived fungus Trichoderma asperellum PSU-PSF14

Three new blennolide derivatives, blennolides L-N (1–3), together with five known metabolites were isolated from the soil-derived fungus Trichoderma asperellum PSU-PSF14. Their structures were determined by analysis of spectroscopic data. Their relative configurations were determined by analysis of NOEDIFF data and confirmed by X-ray crystallography for compound 1 whereas the absolute configurations were established by means of experimental and calculated TDDFT ECD data. Compound 1 displayed antifungal activity against Cryptococcus neoformans ATCC90112 and ATCC90113 flucytosine-resistant with the MIC values of 128 and 64?μg/mL, respectively, and was inactive against noncancerous Vero cell lines.     

The Curing Efficiency and Mechanical Properties of Light-Activated Acrylic Resin

The aim of this investigation was to determine degree of conversion, and flexural and compressive strength of photocurable acrylic resin. The acrylic resins based on bis-phenol A glycidyl dimethacrylate (BisGMA) and triethylene glycol dimethacrylate (TEGDMA) were formulated and then irradiated with red light to form a solid crosslinked polymer. Various post curing conditions were studied to investigate their effects on curing efficiency. Degree of conversion was analyzed by means of Fourier Transform Infrared Spectroscopy (FTIR) to monitor the quantity of remaining acrylic double bond in the cured resin. Three-point bending and compressive strength were tested using Universal Testing Machine (UTM) to evaluate the mechanical performance. Our investigation demonstrated that the formulated acrylic resins were possibly polymerized under irradiation with red light and degree of conversion and mechanical properties were closely correlated.     

Microwave-induced fabrication of copper nanoparticle/carbon nanotubes hybrid material

Copper nanoparticle/multi-walled carbon nanotube (MWCNT) hybrid material could be fabricated by microwave irradiation to a suspension of MWCNTs dispersed in copper precursor with the presence of ethylene glycol. Microscopic and spectroscopic analyses could confirm the uniform dispersion of copper oxide nanoparticles hybridized on the outer surface of MWCNTs. Reduction of Cu²⁺ ions to Cu₂O and Cu nanoparticles was ascribed to functional groups which were generated after the precursor was irradiated by microwave. Sufficient irradiation time of 5 min or longer played an important role to induce the agglomeration of copper oxide nanoparticles on the MWCNT surface.