Surface Modification of Poly(lactic acid) Fabrics with Plasma Pretreatment and Chitosan/Siloxane Polyesters Coating for Color Strength Improvement.

As people in the 21st century become increasingly environmentally aware, environmentally friendly products have come into focus. As such, environmentally friendly textiles and eco-textiles have become an international trend in research and development. Poly(lactic acid) fiber, which is biodegradable, holds much promise, but it is difficult to deep dye. This study used chitosan, succine anhydride, siloxane, and polyethylene glycol to produce a series of chitosan/siloxane polyesters that have a hydrophilic component (chitosan) and a hydrophobic component (siloxane), and this chitosan/siloxane polyester can be coated on poly(lactic acid) fiber, which we had subjected to Argon plasma treatment to increase their antimicrobial properties and to increase the fibers dyeing efficiency. The study shows that, after the surface plasma treatment, longer PEG chain lengths resulted in higher K/S values. This result suggests that the surface plasma pretreatment and chitosan/siloxane polyesters coating showed that lower ∆E values result in more leveling dyeing of poly(lactic acid) fiber.

Differential expression of claudin-4 between intestinal and diffuse-type gastric cancer.

Our previous microarray analysis of gastric cancer found that claudin-4 was differentially expressed between intestinal-type gastric cancer (IGC) and diffuse-type gastric cancer (DGC). Claudin-4 is a member of a large family of transmembrane proteins, claudins, essential in the formation and maintenance of tight junctions. To explore the roles of claudin-4 in the two histologically distinct types of gastric cancer, we selected 45 IGC and 48 DGC cases and then analyzed the expression of the protein using immunohistochemistry. We found that the overexpression of claudin-4 was greater in IGC than in DGC. A trend was observed between the overexpression of claudin-4 and lymph node metastasis, however, this association was not statistically significant. The results showed that the expression of claudin-4 was lower in DGC. Possibly it played a role in determining the diffuse phenotype and loose cohesion of cells in DGC in a similar manner as E-cadherin.

Effect of argon plasma treatment on surface-enhanced Raman spectroscopy of polypyrrole deposited on electrochemically roughened gold substrates.

In this work, polypyrrole (PPy) films were electrodeposited on electrochemically roughened gold substrates modified by argon plasma treatment. First, a gold substrate was roughened by a triangular-wave oxidation-reduction cycle (ORC) in an aqueous solution containing 0.1 N HCl. Then the roughened gold substrate was further treated by argon plasma. Encouragingly, the surface-enhanced Raman scattering (SERS) spectroscopy of polypyrrole electrodeposited on this roughened gold substrate modified by argon plasma treatment exhibits a higher intensity by 8-fold, as compared with the SERS of PPy electrodeposited on an unmodified roughened gold substrate. Meanwhile, the electropolymerization for pyrrole monomers occurring on the modified roughened gold substrate is easier. Also, the nucleation and growth of electropolymerization of pyrrole monomers on the modified and unmodified gold substrates are different.

α-Tocopherol protects keratinocytes against ultraviolet A irradiation by suppressing glutathione depletion, lipid peroxidation and reactive oxygen species generation.

This study aimed to investigate whether α-tocopherol is able to protect keratinocytes against ultraviolet A (UVA) radiation by increasing glutathione (γ-glutamylcysteinylglycine; GSH) levels or decreasing lipid peroxidation and reactive oxygen species (ROS) generation. The cell survival fraction was 43.6% when keratinocytes were irradiated with UVA at a dose of 8 J/cm2. α-Tocopherol was added prior to UVA irradiation and the cell viability was assayed. The cell survival fractions were 60.2, 77.1, 89.0, 92.9 and 96.2% when α-tocopherol was added at concentrations of 2.9, 5.9, 8.8, 11.8 and 14.7 IU/ml, respectively. These results suggested that α-tocopherol is capable of protecting keratinocytes against UVA irradiation. Furthermore, the levels of GSH, lipid peroxidation and ROS were measured. The levels of GSH were 0.354 and 0.600 mmol/g protein in keratinocytes irradiated with UVA (8 J/cm2) and in non-irradiated cells, respectively, whereas they were 0.364, 0.420, 0.525, 0.540 and 0.545 mmol/g protein when α-tocopherol was added at concentrations of 2.9, 5.9, 8.8, 11.8 and 14.7 IU/ml, respectively. The levels of lipid peroxidation were 20.401 or 5.328 µmol/g [malondialdehyde (MDA)/protein] in keratinocytes irradiated with UVA (8 J/cm2) and in non-irradiated cells, respectively, whereas they were 11.685, 6.544, 5.847, 4.390 and 2.164 µmol/g (MDA/protein) when α-tocopherol was added at concentrations of 2.9, 5.9, 8.8, 11.8 and 14.7 IU/ml, respectively. The levels of ROS were 3,952.17 or 111.87 1/mg protein in keratinocytes irradiated with UVA (8 J/cm2) and in non-irradiated cells, respectively, whereas they were 742.48, 579.36, 358.16, 285.63 and 199.82 1/mg protein when α-tocopherol was added at concentrations of 2.9, 5.9, 8.8, 11.8 and 14.7 IU/ml, respectively. These findings suggested that α-tocopherol protects keratinocytes against UVA irradiation, possibly through increasing the levels of GSH or decreasing the levels of lipid peroxidation and ROS generation.

Claudin-4 expression in gastric cancer cells enhances the invasion and is associated with the increased level of matrix metalloproteinase-2 and -9 expression.

Claudin-4 is a member of a large family of transmembrane proteins known as claudins, which are essential for the formation and maintenance of tight junctions. Our previous studies have revealed that claudin-4 proteins are overexpressed in metastatic gastric cancer. To clarify the roles of claudin-4 in gastric cancer metastasis, human gastric adenocarcinoma (AGS) cells constitutively expressing wild-type claudin-4 were generated. Expression of claudin-4 in AGS cells was found to increase cell invasion and migration, as measured by Boyden invasion chamber assays. Moreover, the claudin-4-expressing AGS cells were found to have increased matrix metalloproteinase (MMP)-2 and -9 expression, indicating that claudin-mediated increased invasion may be mediated through the activation of the MMP protein. Overall, the results suggest that claudin-4 overexpression may promote gastric cancer metastasis through the increased invasion of gastric cancer cells.

The cytotoxicity of mercury chloride to the keratinocytes is associated with metallothionein expression.

There are trace amounts of heavy metals in cosmetics. Heavy metals such as mercury (Hg), which is added to skin-whitening cosmetics, may cause acute or chronic damage to human cells. The aim of this study was to investigate the cytotoxicity of mercury chloride (HgCl2) to human keratinocytes. The keratinocytes were treated with various concentrations of HgCl2 and the cell survival fractions were found to be 38.08, 17.59, 12.76, 3.29 and 0.77% when the cells were treated with 0.25, 0.5, 0.75, 1 and 1.5 µM of HgCl2, respectively. Moreover, we observed that the greatest damage was to the cell membrane. The metallothionein (MT) protein expression was also investigated. MT expression levels increased with increasing concentrations of HgCl2. The results indicated that MT protects the keratinocytes against HgCl2-induced toxicity.

Magnesium ascorbyl phosphate and coenzyme Q10 protect keratinocytes against UVA irradiation by suppressing glutathione depletion.

The aim of this study was to investigate whether magnesium ascorbyl phosphate (MAP) and coenzyme Q10 (CoQ10) can protect keratinocytes against ultraviolet (UV)A irradiation by increasing the levels of glutathione (GSH). The cell survival fraction was 89.9% when the keratinocytes were irradiated with UVA at a dose of 4 J/cm2. The cell survival fractions were 48.4, 9.1 and 4.8%, at doses of 8, 16 and 32 J/cm2, respectively. MAP was added to the cells prior to UVA irradiation at a dose of 8 J/cm2 and then the cell viability was assayed. The cell survival fractions were 51.6, 55.5, 64.8 and 76.7%, when MAP was added at concentrations of 125, 250, 500 µM and 1 mM, respectively. The results showed that MAP is capable of protecting keratinocytes against UVA irradiation. The cell survival fractions were 77.2, 89.4 and 90.1%, when CoQ10 was added at concentrations of 2.5, 5 and 10 µM, respectively. The results revealed that CoQ10 is capable of protecting keratinocytes against UVA irradiation. At the same time, the levels of GSH within cells were detected. The level of GSH within cells was 0.3 mmol/g protein when the keratinocytes were irradiated with UVA at a dose of 8 J/cm2. We measured the levels of GSH within the cells after MAP or CoQ10 was added prior to UVA irradiation at a dose of 8 J/cm2. The levels of GSH within the cells were 0.344, 0.388, 0.456 and 0.5 mmol/g protein, when MAP was added at concentrations of 125, 250, 500 µM and 1 mM, respectively. The levels of GSH within the cells were 0.328, 0.35 and 0.394 mmol/g protein, when CoQ10 was added at concentrations of 2.5, 5 and 10 µM, respectively. These results imply that MAP and CoQ10 can protect the keratinocytes against UVA irradiation, possibly via increasing the levels of GSH.

CCL7 and CCL21 overexpression in gastric cancer is associated with lymph node metastasis and poor prognosis.

AIM: To investigate how a complex network of CC chemokine ligands (CCLs) and their receptors influence the progression of tumor and metastasis. METHODS: In the present study, we used immunohistochemistry to examine the expression of CCL7, CCL8 and CCL21 in 194 gastric cancer samples and adjacent normal tissues. We analyzed their correlation with tumor metastasis, clinicopathologic parameters and clinical outcome. RESULTS: We found that the higher expression of CCL7 and CCL21 in cancer tissues than in normal tissues was significantly correlated with advanced depth of wall invasion, lymph node metastasis and higher tumor node metastasis stage. Moreover, Kaplan-Meier survival analysis revealed that CCL7 and CCL21 overexpression in cancer tissues was correlated with poor prognosis. CONCLUSION: These results suggest that overexpression of these two CC chemokine ligands is associated with tumor metastasis and serves as a prognostic factor in patients with gastric cancer.

Claudin-4 expression is associated with tumor invasion, MMP-2 and MMP-9 expression in gastric cancer.

Claudin-4 is a member of the claudin family, a large family of transmembrane proteins that are essential in the formation and maintenance of tight junctions. Matrix metal-loproteinase (MMP)-2 and -9 degrade type IV collagen of the extracellular matrix and basal membranes. Claudin-4 activates MMP-2, indicating that claudin-mediated increased cancer cell invasion may result from the activation of MMP proteins. In the present study, we used immunohistochemistry to examine the expression levels of claudin-4, MMP-2 and MMP-9 in 189 gastric cancer samples, and analyzed their correlation with tumor invasion, clinicopathologic parameters and clinical outcome. The relationship between claudin-4 expression and MMP-2 and -9 expression was also investigated. The expression of claudin-4 was found to be significantly higher in gastric cancer cases with advanced depth of wall invasion, lymph node metastasis, lymphatic invasion and higher TNM stage. Further analysis revealed claudin-4 expression to be significantly correlated with the expression of MMP-2 and -9. Kaplan-Meier survival analysis indicated that MMP-9 expression was correlated with poor prognosis. These results suggest that claudin-4 expression is associated with tumor invasion and with MMP-2 and -9 expression in gastric cancer. Additionally, MMP-9 expression was demonstrated to serve as a prognostic factor in patients with gastric cancer.

Expression of matrix metalloproteinases MMP-2 and MMP-9 in gastric cancer and their relation to claudin-4 expression.

Matrix metalloproteinases (MMPs) MMP-2 and MMP-9 can degrade type IV collagen of extracellular matrix and basal membranes. Claudin-4 is a member of a large family of transmembrane proteins, claudins, essential in the formation and maintenance of tight junctions. Claudin-4 has been shown to activate MMP-2, indicating that claudin-mediated increased cancer cell invasion might be mediated through the activation of MMP proteins. To explore the roles of MMP-2, MMP-9 and claudin-4 in gastric cancer, we selected 88 cases and then analyzed the expression of these proteins using immunohistochemistry. We found that all of MMP-2, MMP-9 and claudin-4 expressions were significantly higher in intestinal-type than in diffuse-type gastric cancer. On further analysis, testing the relationship between MMP-2 and MMP-9 expression with claudin-4 expression, claudin-4 expression was significantly associated with MMP-9 expression, but not with MMP-2 expression. The results showed that MMP-2, MMP-9 and claudin-4 expression may be phenotypic features, distinguishing intestinal-type and diffuse-type gastric cancer. Possibly, claudin-4 played a role in determining MMP-9 activity which favored intestinal-type gastric cancer to distal metastasis.