Synthesis of Cytocompatible Luminescent Titania/Fluorescein Hybrid Nanoparticles

Luminescent titania-fluorescein (FS) hybrid nanoparticles (NPs) were successfully synthesized by a sol–gel reaction of titanium alkoxide in the presence of octadecylamine using a fluidic reactor with a Y-type channel. The molar ratio of FS/Ti ratio was varied in the range from 1/1000 to 1/100 in order to obtain the hybrid NPs with the different luminescent behavior. The shape of the NPs is spherical and their sizes are 400 nm which is almost the same irrespective of the FS content, suggesting the different FS molecular states in one NP. We also demonstrated that the hybrid NPs exhibited a characteristic luminescence; the NPs with the higher and lower FS contents exhibited an enhanced luminescence in PBS and air, respectively, indicating that the FS states responded to the molecular environment. Through cytocompatible experiments using the NPs, it turned out that they had a high compatibility for fibroblasts. Therefore, the preparation of a series of the luminescent NPs with a tunable luminescence property was achieved. The results will lead to a guideline to determine a proper combination between material composition and an environment where they are used, being useful for biomedical applications

Templating Effect of Mesostructured Surfactant–Silica Monolithic Films on the Surface Structural and Mechanical Properties

Mesostructured surfactant–silica monolithic films were prepared using a supramolecular templating method. The effect of the templating in the monolithic films on the interfacial interactions was evaluated and elucidated using the atomic force microscope techniques combined with other surface analyses to produce different surface structures and force curves depending on the surfactants. The transparent and flexible surfactant–silica monolithic films were prepared to exhibit the ordered nanostructures. The monolithic films templated by nonionic triblock copolymers (poly­(ethylene oxide (EO))–poly­(propylene oxide (PO))–poly­(ethylene oxide (EO))) of EO₂₀PO₇₀EO₂₀ (P123) and EO₁₀₆PO₇₀EO₁₀₆ (F127) significantly exhibited flat surfaces and the higher viscoelastic properties which were supported by surface stiffness and adhesive force, whereas the monolithic film by cationic alkylammonium surfactant indicated a rough surface and the plastic deformation property by application of force. This indicated that the higher molecular weight of the EO and PO phases enhanced the phase segregation in the silica surfaces due to the higher solubility differences between both blocks to consolidate the surfactant–silica interfacial interactions. Therefore, the different surface structural and mechanical properties attributed to the interfacial organic–inorganic interaction patterns were successfully clarified

Simplified detection of the hybridized DNA using a graphene field effect transistor

<p>Detection of disease-related gene expression by DNA hybridization is a useful diagnostic method. In this study a monolayer graphene field effect transistor (GFET) was fabricated for the detection of a particular single-stranded DNA (target DNA). The probe DNA, which is a single-stranded DNA with a complementary nucleotide sequence, was directly immobilized onto the graphene surface without any linker. The V_Dirac was shifted to the negative direction in the probe DNA immobilization. A further shift of V_Dirac in the negative direction was observed when the target DNA was applied to GFET, but no shift was observed upon the application of non-complementary mismatched DNA. Direct immobilization of double-stranded DNA onto the graphene surface also shifted the V_Dirac in the negative direction to the same extent as that of the shift induced by the immobilization of probe DNA and following target DNA application. These results suggest that the further shift of V_Dirac after application of the target DNA to the GFET was caused by the hybridization between the probe DNA and target DNA.</p

Mesoporous Silica Nanoparticles Capped with Graphene Quantum Dots for Potential Chemo–Photothermal Synergistic Cancer Therapy

In this study, mesoporous silica nanoparticles (MSNs) have been successfully capped with graphene quantum dots (GQDs) to form multifunctional GQD–MSNs with the potential for synergistic chemo–photothermal therapy. The structure, drug-release behavior, photothermal effect, and synergistic therapeutic efficiency of GQD–MSNs to 4T1 breast cancer cells were investigated. The results showed that GQD–MSNs were monodisperse and had a particle size of 50–60 nm. Using doxorubicin hydrochloride (DOX) as a model drug, the DOX-loaded GQD–MSNs (DOX–GQD–MSNs) not only exhibited pH- and temperature-responsive drug-release behavior, but using near-infrared irradiation, they efficiently generated heat to kill cancer cells. Furthermore, GQD–MSNs were biocompatible and were internalized by 4T1 cells. Compared with chemotherapy and photothermal therapy alone, DOX–GQD–MSNs were much more effective in killing the 4T1 cells owing to a synergistic chemo–photothermal effect. Therefore, GQD–MSNs may have promising applications in cancer therapy

Gene chip/PCR-array analysis of tissue response to 2-methacryloyloxyethyl phosphorylcholine (MPC) polymer surfaces in a mouse subcutaneous transplantation system

<div><p>To evaluate the <i>in vivo</i> foreign body reaction to bio-inert 2-methacryloyloxyethyl phosphorylcholine (MPC) polymers, MPC polymer-coated porous substrates, with large surface area, were implanted subcutaneously in mice for 7 and 28 days, and the surrounding tissue response and cells infiltrating into the porous structure were evaluated. The MPC polymer surface induced low angiogenesis and thin encapsulation around the porous substrate, and slightly suppressed cell infiltration into the porous substrate. M1-type macrophage specific gene (CCR7) expression was suppressed by the MPC polymer surface after 7 days, resulting in the suppression of inflammatory cytokine/chemokine gene expression. However, the expression of these genes on the MPC polymer surface was higher than on the non-coated surface after 28 days. These findings suggest that MPC polymer surfaces successfully inhibit inflammatory responses during the early stage of tissue response, and seem to retard its occurrence over time.</p></div

Descriptions and expression levels of genes which were up-regulated in collagen and down-regulated in PMB.

<p>Numbers in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0085132#pone-0085132-g006" target="_blank">Fig. 6</a> correspond to those in the table. Plus and minus in this table indicate promotion and suppression, respectively.</p

Bone nodule formation of osteoblast cells in the presence and absence of 2BP.

<p>A-C) Time-dependent bone nodule formation in the osteoblast cells A) in the absence of 2BP, B) in the presence of 2BP and 0.1% DMSO, and C) in the presence of 0.1% DMSO. The mineralized nodules are stained with Alizarin Red. D) The area occupied by the mineralized nodules (%) was plotted against the incubation time (day). Error bars indicate the standard error. E) Enlargement of the mineralized nodules on Day 21. In the presence of 2BP (panel b), the nodules were more diffuse (none were clustered) than in the other two conditions (panels a and c). On Day 0, the osteoblast cell differentiation was initiated. These experiments were carried out 3 times.</p

Microscopic histological observations by HE staining (A, C, and E) and CD68 immunostaining (B, D, and F) of non-coat (A and B), PMB-coated (C and D), and collagen-coated (E and F) scaffolds at boundary between scaffold and tissue.

<p>Small vessels (arrow heads) and macrophages (arrows) were observed. The mean pore size of the scaffolds was 157 µm. Seven days after operation. Some scaffold skeletons (S) are detached from sliced samples. Bars  = 50 µm.</p

Comparison of the amino-acid sequences of IFITM proteins and illustration of protein S-palmitoylation.

<p>A) Amino-acid sequence alignment of IFITM5, IFITM1, IFITM2, and IFITM3 derived from mice. The conserved residues are highlighted in black. The three conserved cysteines are highlighted in red and numbered based on the sequence of IFITM5 (top) and IFITM3 (bottom). The residues unique in IFITM5 are highlighted in gray. The first and the second transmembrane domains, the extracellular sequences, and the cytoplasmic loop are indicated by arrows and denoted as TM1 and TM2, EC, and the CP loop, respectively. The TM domains were predicted by SOSUI. The aspartates at the C-terminal region in IFITM5 are shown in blue. B) The schematic illustration of the protein S-palmitoylation. The C₁₆-palmitic acid is attached to cysteine via a thioester linkage. The palmitoylation and depalmitoylation are catalyzed by protein acyltransferases and acylprotein thioesterases, respectively. In this study, hydroxylamine, NH ₂OH, was used to reduce the thioester linkage. C) The amino acid sequence identity (similarity) among IFITM5, IFITM1, IFITM2, and IFITM3 is summarized.</p

Macroscopic observation of implanted scaffold with non-coat (A), PMB-coated (B), and collagen-coated (C) scaffold which were sliced and stained with HE.

<p>Scaffold mean pore size was 157 µm. Scaffolds were attached to rat dorsal skin and encapsulated with layer of fibrous tissue (arrows). Some scaffold skeletons (S) are detached from sliced sample. Bars  = 1 mm.</p