Evaluation of porous bacterial cellulose produced from foam templating with different additives and its application in 3D cell culture.

Bacterial cellulose (BC) is used in biomedical applications due to its unique material properties such as mechanical strength with a high water-absorbing capacity and biocompatibility. Nevertheless, native BC lacks porosity control which is crucial for regenerative medicine. Hence, developing a simple technique to change the pore sizes of BC has become an important issue. This study combined current foaming BC (FBC) production with incorporation of different additives (avicel, carboxymethylcellulose, and chitosan) to form novel porous additive-altered FBC. Results demonstrated that the FBC samples provided greater reswelling rates (91.57 % ~ 93.67 %) compared to BC samples (44.52 % ~ 67.5 %). Moreover, the FBC samples also showed excellent cell adhesion and proliferation abilities for NIH-3T3 cells. Lastly, FBC allowed cells to penetrate to deep layers for cell adhesion due to its porous structure, providing a competitive scaffold for 3D cell culture in tissue engineering.

G2/M arrest and apoptosis of human colorectal cancer cells induced by water extract from residues of jelly fig achene.

Jelly fig (Ficus awkeotsang) achenes have been utilized to prepare a traditional drink in Taiwan. Herein, we evaluated the effect of water extract from jelly fig seed residues (WERJFA) on cancer cells. WERJFA could inhibit the growth of human colorectal cancer cells, COLO205 and HT29 in both dose- and time-dependent manners. The flow cytometric analysis with propidium iodide (PI) showed that WERJFA primarily arrested COLO205 and HT29 cells at the G2/M phase of cell cycle as the concentration reached to at least 0.5 mg/ml. WERJFA induced apoptosis of these two cell lines, as evidenced by annexin V-FITC/PI and 4', 6-diamidino-2-phenylindole (DAPI) staining using flow cytometry and confocal microscopy, respectively. Reactive oxygen species (ROS) production and the loss of mitochondrial membrane potential in WERJFA-treated cells were detected by flow cytometry with H2DCF-DA and 5,5', 6,6'-Tetrachloro-1, 1', 3,3'-tetraethylbenzimidazolocarbocyanine iodide (JC-1). Our results showed that WERJFA exerted anti-proliferative and apoptotic effects on colorectal cancer cells. WERJFA arrested cell cycle, and caused apoptotic death in these cancer cells possibly via mitochondrial pathway involved with exceeding ROS level.

G2/M arrest and apoptosis of human colorectal cancer cells induced by water extract from residues of jelly fig achene.

Jelly fig (Ficus awkeotsang) achenes have been utilized to prepare a traditional drink in Taiwan. Herein, we evaluated the effect of water extract from jelly fig seed residues (WERJFA) on cancer cells. WERJFA could inhibit the growth of human colorectal cancer cells, COLO205 and HT29 in both dose- and time-dependent manners. The flow cytometric analysis with propidium iodide (PI) showed that WERJFA primarily arrested COLO205 and HT29 cells at the G2/M phase of cell cycle as the concentration reached to at least 0.5 mg/ml. WERJFA induced apoptosis of these two cell lines, as evidenced by annexin V-FITC/PI and 4', 6-diamidino-2-phenylindole (DAPI) staining using flow cytometry and confocal microscopy, respectively. Reactive oxygen species (ROS) production and the loss of mitochondrial membrane potential in WERJFA-treated cells were detected by flow cytometry with H2DCF-DA and 5,5', 6,6'-Tetrachloro-1, 1', 3,3'-tetraethylbenzimidazolocarbocyanine iodide (JC-1). Our results showed that WERJFA exerted anti-proliferative and apoptotic effects on colorectal cancer cells. WERJFA arrested cell cycle, and caused apoptotic death in these cancer cells possibly via mitochondrial pathway involved with exceeding ROS level.

Active and stable liquid water innovatively prepared using resonantly illuminated gold nanoparticles.

The properties of confined liquid water, or liquid water in contact with hydrophobic surfaces, are significantly different from those of bulk liquid water. However, all of water's commonly described properties are related to inert "bulk liquid water" which comprises a tetrahedral hydrogen-bonded network. In this work, we report an innovative and facile method for preparing small water clusters (SWCs) with reduced affinity hydrogen bonds by letting bulk water flow through supported Au nanoparticles (NPs) under resonant illumination to give NP-treated (AuNT) water at constant temperature. Utilizing localized surface plasmon resonance on illuminated Au NPs, the strong hydrogen bonds of bulk water can be disordered when water is located at the illuminated Au/water interface. The prepared SWCs are free of Au NPs. The energy efficiency for creating SWCs is ∼17%. The resulting stable AuNT water exhibits distinct properties at room temperature, which are significantly different from the properties of untreated bulk water, examples being their ability to scavenge free hydroxyl and 2,2-diphenyl-1-picrylhydrazyl radicals and to effectively reduce NO release from lipopolysaccharide-induced inflammatory cells.

Detection of apoptosis and necrosis in normal human lung cells using 1H NMR spectroscopy.

This study aimed to detect apoptosis and necrosis in MRC-5, a normal human lung cell line, by using noninvasive proton nuclear magnetic resonance (1H NMR). Live MRC-5 cells were processed first for 1H NMR spectroscopy; subsequently their types and the percentage of cell death were assessed on a flow cytometer. Cadmium (Cd) and mercury (Hg) induced apoptosis and necrosis in MRC-5 cells, respectively, as revealed by phosphatidylserine externalization on a flow cytometer. The spectral intensity ratio of methylene (CH2) resonance (at 1.3 ppm) to methyl (CH3) resonance (at 0.9 ppm) was directly proportional to the percentage of apoptosis and strongly and positively correlated with PI staining after Cd treatment (r2 = 0.9868, P < 0.01). In contrast, this ratio only increased slightly within 2-h Hg treatment, and longer Hg exposure failed to produce further increase. Following 2-h Hg exposure, the spectral intensity of choline resonance (at 3.2 ppm) was abolished, but this phenomenon was absent in Cd-induced apoptosis. These findings together demonstrate that 1H NMR is a novel tool with a quantitative potential to distinguish apoptosis from necrosis as early as the onset of cell death in normal human lung cells.

Mediating of caspase-independent apoptosis by cadmium through the mitochondria-ROS pathway in MRC-5 fibroblasts.

Cadmium (Cd) is an environmental pollutant of global concern with a 10-30-year biological half-life in humans. Accumulating evidence suggests that the lung is one of the major target organs of inhaled Cd compounds. Our previous report demonstrated that 100 microM Cd induces MRC-5 cells, normal human lung fibroblasts, to undergo caspase-independent apoptosis mediated by mitochondrial membrane depolarization and translocation of apoptosis-inducing factor (AIF) from mitochondria into the nucleus. Here, using benzyloxycarbonyl-Val-Ala-Asp-(ome) fluoromethyl ketone (Z-VAD.fmk) as a tool, we further demonstrated that Cd could induce caspase-independent apoptosis at concentrations varied from 25 to 150 microM, which was modulated by reactive oxygen species (ROS) scavengers, such as N-acetylcysteine (NAC), mannitol, and tiron, indicating that ROS play a crucial role in the apoptogenic activity of Cd. Consistent with this notion, the intracellular hydrogen peroxide (H2O2) was 2.9-fold elevated after 3 h of Cd treatment and diminished rapidly within 1 h as detected by flow cytometry with 2',7'-dichlorodihydrofluorescein diacetate (DCFH-DA) staining. Using inhibitors of the mitochondrial electron transport chain (ETC) (oligomycin A and rotenone for complex I and V, respectively) and mitochondrial permeability transition pore (MPTP) (cyclosporin A and aristolochic acid), we coincidently found the ROS production, mitochondrial membrane depolarization, and apoptotic content were almost completely or partially abolished. As revealed by confocal microscopy staining with chloromethyl-X-rosamine (CMXRos) and an anti-AIF antibody, the collapse of mitochondrial membrane potential induced by Cd (3 h-treatment) was a prelude to the translocation of caspase-independent pro-apoptotic factor, AIF, into the nucleus (after 4 h of Cd treatment). In summary, this study demonstrated that, in MRC-5 fibroblasts, Cd induced caspase-independent apoptosis through a mitochondria-ROS pathway. More importantly, we provide several lines of evidence supporting a role of mitochondrial ETC and MPTP in the regulation of caspase-independent cell death triggered by Cd.