Photoswitchable Microgels for Dynamic Macrophage Modulation.

Dynamic manipulation of supramolecular self-assembled structures is achieved irreversibly or under non-physiological conditions, thereby limiting their biomedical, environmental, and catalysis applicability. In this study, microgels composed of azobenzene derivatives stacked via π-cation and π-π interactions are developed that are electrostatically stabilized with Arg-Gly-Asp (RGD)-bearing anionic polymers. Lateral swelling of RGD-bearing microgels occurs via cis-azobenzene formation mediated by near-infrared-light-upconverted ultraviolet light, which disrupts intermolecular interactions on the visible-light-absorbing upconversion-nanoparticle-coated materials. Real-time imaging and molecular dynamics simulations demonstrate the deswelling of RGD-bearing microgels via visible-light-mediated trans-azobenzene formation. Near-infrared light can induce in situ swelling of RGD-bearing microgels to increase RGD availability and trigger release of loaded interleukin-4, which facilitates the adhesion structure assembly linked with pro-regenerative polarization of host macrophages. In contrast, visible light can induce deswelling of RGD-bearing microgels to decrease RGD availability that suppresses macrophage adhesion that yields pro-inflammatory polarization. These microgels exhibit high stability and non-toxicity. Versatile use of ligands and protein delivery can offer cytocompatible and photoswitchable manipulability of diverse host cells.

Manipulating Nanoparticle Aggregates Regulates Receptor-Ligand Binding in Macrophages.

The receptor-ligand interactions in cells are dynamically regulated by modulation of the ligand accessibility. In this study, we utilize size-tunable magnetic nanoparticle aggregates ordered at both nanometer and atomic scales. We flexibly anchor magnetic nanoparticle aggregates of tunable sizes over the cell-adhesive RGD ligand (Arg-Gly-Asp)-active material surface while maintaining the density of dispersed ligands accessible to macrophages at constant. Lowering the accessible ligand dispersity by increasing the aggregate size at constant accessible ligand density facilitates the binding of integrin receptors to the accessible ligands, which promotes the adhesion of macrophages. In high ligand dispersity, distant magnetic manipulation to lift the aggregates (which increases ligand accessibility) stimulates the binding of integrin receptors to the accessible ligands available under the aggregates to augment macrophage adhesion-mediated pro-healing polarization both in vitro and in vivo. In low ligand dispersity, distant control to drop the aggregates (which decreases ligand accessibility) repels integrin receptors away from the aggregates, thereby suppressing integrin receptor-ligand binding and macrophage adhesion, which promotes inflammatory polarization. Here, we present "accessible ligand dispersity" as a novel fundamental parameter that regulates receptor-ligand binding, which can be reversibly manipulated by increasing and decreasing the ligand accessibility. Limitless tuning of nanoparticle aggregate dimensions and morphology can offer further insight into the regulation of receptor-ligand binding in host cells.

Cytokine secreted by S100A9 via TLR4 in monocytes delays neutrophil apoptosis by inhibition of caspase 9/3 pathway.

Dysregulation of neutrophil apoptosis causes pathogenesis and aggravation of allergy. S100A9 exists as one of the proteins in the neutrophils, triggering inflammatory responses by activating the immune cells. In this study, we investigated whether S100A9 affects constitutive neutrophil apoptosis by activating the monocytes in normal and allergic subjects. Supernatant from human monocytic THP-1 cells after treatment with S100A9 suppressed normal neutrophil apoptosis by inhibiting the activations of caspase 9 and caspase 3. S100A9 upregulated the release of MCP-1, IL-6, and IL-8 in THP-1 cells. An increase in cytokine was suppressed by CLI-095, a Toll-like receptor (TLR) 4 inhibitor, PP2, a Src inhibitor, rottlerin, a PKCδ inhibitor, MAP kinase inhibitors, including PD98059, SB202190, and SP600125, and BAY-11-7085, an NF-κB inhibitor. Src, PKCδ, ERK1/2, p38 MAPK, and JNK were phosphorylated by S100A9. The phosphorylation of Src and PKCδ was suppressed by CLI-095, and the activation of ERK1/2, p38 MAPK, and JNK was inhibited by CLI-095, PP2, and rottlerin. S100A9 induced NF-κB activity, and the activation was suppressed by CLI-095, PP2, rottlerin, and MAPK kinase inhibitors. In normal and allergic subjects, supernatant from normal and allergic monocytes after stimulation with S100A9 suppressed normal and allergic neutrophil apoptosis, respectively; MCP-1, IL-6, and IL-8 in the supernatant was increased by S100A9. The cytokine secretion induced by S100A9 is related to TLR4, Src, PKCδ, ERK1/2, p38 MAPK, JNK, and NF-κB. Taken together, S100A9 induces anti-apoptotic effect on normal and allergic neutrophils by increasing cytokine secretion of monocytes. These findings may help us to better understand neutrophil apoptosis regulated by S100A9 and pathogenesis of allergic diseases.

Preparation of nano/macroporous polycaprolactone microspheres for an injectable cell delivery system using room temperature ionic liquid and camphene.

The nano/macroporous polycaprolactone (PCL) microspheres with cell active surfaces were developed as an injectable cell delivery system. Room temperature ionic liquid (RTIL) and camphene were used as a liquid mold and a porogen, respectively. Various-sized spheres of 244-601µm with pores of various size and shape of 0.02-100µm, were formed depending on the camphene/RTIL ratio (0.8-2.6). To give cell activity, the surface of porous microspheres were further modified with nerve growth factors (NGF) containing gelatin to give a thin NGF/gelatin layer, to which the neural progenitor cells (PC-12) attached and extended their neurites on to the surface layers of the microspheres. The developed microspheres may be potentially applicable as a neuronal cell delivery scaffold for neuron tissue engineering.

Production of CNT-taxol-embedded PCL microspheres using an ammonium-based room temperature ionic liquid: as a sustained drug delivery system.

We describe a one-pot method for the mass production of polymeric microspheres containing water-soluble carbon-nanotube (w-CNT)-taxol complexes using an ammonium-based room temperature ionic liquid. Polycaprolactone (PCL), trioctylmethylammonium chloride (TOMAC; liquid state from -20 to 240°C), and taxol were used, respectively, as a model polymer, room temperature ionic liquid, and drug. Large quantities of white colored PCL powder without w-CNT-taxol complexes and gray colored PCL powders containing w-CNT-taxol (1:1 or 1:2 wt/wt) complexes were produced by phase separation between the hydrophilic TOMAC and the hydrophobic PCL. Both microsphere types had a uniform, spherical structure of average diameter 3-5µm. The amount of taxol embedded in PCL microspheres was determined by HPLC and (1)H NMR to be 8-12µg per 1.0mg of PCL (loading capacity (LC): 0.8-1.2%; entrapment efficiency (EE): 16-24%). An in vitro HPLC release assay showed sustain release of taxol without an initial burst over 60days at an average rate of 0.003-0.0073mg per day. The viability patterns of human breast cancer cells (MCF-7) for PCTx-1 and -2 showed dose-dependent inhibitory effects. In the presence of PCTx-1 and -2, the MCF-7 cells showed high viability in the concentration level of, respectably, <70 and <5µg/mL.

Improvement of H2S sensing properties of SnO2-based thick film gas sensors promoted with MoO3 and NiO.

The effects of the SnO2 pore size and metal oxide promoters on the sensing properties of SnO2-based thick film gas sensors were investigated to improve the detection of very low H2S concentrations (<1 ppm). SnO2 sensors and SnO2-based thick-film gas sensors promoted with NiO, ZnO, MoO3, CuO or Fe2O3 were prepared, and their sensing properties were examined in a flow system. The SnO2 materials were prepared by calcining SnO2 at 600, 800, 1,000 and 1,200 °C to give materials identified as SnO2(600), SnO2(800), SnO2(1000), and SnO2(1200), respectively. The Sn(12)Mo5Ni3 sensor, which was prepared by physically mixing 5 wt% MoO3 (Mo5), 3 wt% NiO (Ni3) and SnO2(1200) with a large pore size of 312 nm, exhibited a high sensor response of approximately 75% for the detection of 1 ppm H2S at 350 °C with excellent recovery properties. Unlike the SnO2 sensors, its response was maintained during multiple cycles without deactivation. This was attributed to the promoter effect of MoO3. In particular, the Sn(12)Mo5Ni3 sensor developed in this study showed twice the response of the Sn(6)Mo5Ni3 sensor, which was prepared by SnO2(600) with the smaller pore size than SnO2(1200). The excellent sensor response and recovery properties of Sn(12)Mo5Ni3 are believed to be due to the combined promoter effects of MoO3 and NiO and the diffusion effect of H2S as a result of the large pore size of SnO2.

Timing of chemotherapy-induced neutropenia is a prognostic factor in patients with metastatic non-small-cell lung cancer: a retrospective analysis in gemcitabine-plus-platinum-treated patients.

PURPOSE: Chemotherapy-induced neutropenia (CIN) has been associated with better therapeutic results in studies of various tumors. Herein, we explored the relationship between timing (onset) of CIN and clinical outcomes of patients with metastatic non-small-cell lung cancer (NSCLC). METHODS: Patients with stage IV NSCLC receiving at least two cycles of first-line doublet chemotherapy (gemcitabine plus platinum) were reviewed retrospectively. Subjects were stratified by onset of CIN into two groups: early-onset (lowest neutrophil count of cycles 1-2 <2.0 × 10(9)/L) and non-early-onset. The non-early-onset group was further subdivided into late-onset (lowest neutrophil count of cycles 3-6 <2.0 × 10(9)/L) and absence of neutropenia. RESULTS: A total of 123 patients were studied. Significantly better disease control rate, progression-free survival (PFS), and overall survival (OS) were observed in early-onset versus non-early-onset patients. Median PFS of 5.1 and 3.8 months (p = 0.0016) and median OS of 16.7 and 11.2 months (p = 0.0004) were achieved for these groups, respectively. Patient subsets with late-onset and absence of neutropenia showed similarly poor clinical outcomes, with 4.8 and 3.8 months median PFS (p = 0.5067) and 13.0 and 11.2 months median OS (p = 0.6304), respectively. CONCLUSIONS: Timing of CIN is predictive of prognosis in patients with metastatic NSCLC receiving gemcitabine/platinum doublet chemotherapy. Better clinical outcomes were achieved when onset of neutropenia was early versus late or absent altogether. Further research is warranted to determine whether above findings are applicable to other chemotherapeutic regimens.

Safety and efficacy of deep sedation with propofol alone or combined with midazolam administrated by nonanesthesiologist for gastric endoscopic submucosal dissection.

BACKGROUND/AIMS: Endoscopic submucosal dissection (ESD) is accepted as a treatment for gastric neoplasms and usually requires deep sedation. The aim of this study was to evaluate the safety and efficacy profiles of deep sedation induced by continuous propofol infusion with or without midazolam during ESD. METHODS: A total of 135 patients scheduled for ESDs between December 2008 and June 2010 were included in this prospective study and were randomly assigned to one of two groups: the propofol group or the combination group (propofol plus midazolam). RESULTS: The propofol group reported only one case of severe hypoxemia with no need of mask ventilation or intubation. Additionally, 18 cases of mild hypotension were observed in the propofol group, and 11 cases were observed in the combination group. The combination group had a lower mean total propofol dose (378 mg vs 466 mg, p<0.012), a longer mean recovery time (10.5 minutes vs 7.9 minutes, p=0.027), and a lower frequency of overall adverse events (32.8% vs 17.6%, p=0.042). CONCLUSIONS: Deep sedation induced by continuous propofol infusion was shown to be safe during ESD. The combination of continuous propofol infusion and intermittent midazolam injection can decrease the total dose and infusion rate of propofol and the overall occurrence of adverse events.

Effects of textural properties on the response of a SnO2-based gas sensor for the detection of chemical warfare agents.

The sensing behavior of SnO(2)-based thick film gas sensors in a flow system in the presence of a very low concentration (ppb level) of chemical agent simulants such as acetonitrile, dipropylene glycol methyl ether (DPGME), dimethyl methylphosphonate (DMMP), and dichloromethane (DCM) was investigated. Commercial SnO(2) [SnO(2)(C)] and nano-SnO(2) prepared by the precipitation method [SnO(2)(P)] were used to prepare the SnO(2) sensor in this study. In the case of DCM and acetonitrile, the SnO(2)(P) sensor showed higher sensor response as compared with the SnO(2)(C) sensors. In the case of DMMP and DPGME, however, the SnO(2)(C) sensor showed higher responses than those of the SnO(2)(P) sensors. In particular, the response of the SnO(2)(P) sensor increased as the calcination temperature increased from 400 °C to 800 °C. These results can be explained by the fact that the response of the SnO(2)-based gas sensor depends on the textural properties of tin oxide and the molecular size of the chemical agent simulant in the detection of the simulant gases (0.1-0.5 ppm).

[Prevalence and risk factors of gallbladder polyp in adults living in Daegu and Gyeongbuk provinces].

BACKGROUND/AIMS: Although there are various reports on the prevalence of gallbladder (GB) polyp according to the race or area, there is no report on Daegu and Gyeongbuk provinces. Therefore, we investigated the prevalence and related risk factors of GB polyp in health screening population of Daegu and Gyeongbuk provinces. METHODS: Of 28,911 adult health screening examinees from January 1997 to May 2003, age and gender-matched 8,008 (3,896 men, 4,112 women) were randomly selected to evaluate the prevalence. Independent risk factors were analyzed by comparing various variables between the GB polyp positive and negative groups. RESULTS: The prevalence of GB polyp was 2.2% (175/8,008). Those were 2.7% (104/3,896) among men and 1.7% (71/4,112) among women. Independent risk factors related with GB polyp were male gender (OR 1.434, p<0.001), obesity (OR 1.237, p=0.024), and hepatitis B carrier (OR 1.888, p<0.001) CONCLUSIONS: Prevalence of GB polyp in Daegu and Gyeongbuk provinces is 2.2%. Male, obesity, and hepatitis B carrier may be the risk factors related with GB polyp in this region.