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Nuri Oh,1,2 Ji-Ho Park1–31Department of Bio and Brain Engineering, 2Institute for Optical Science and Technology, 3Institute for the NanoCentury, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, Republic of KoreaAbstract: Engineered nanoparticles that can be injected into the human body hold tremendous potential to detect and treat complex diseases. Understanding of the endocytosis and exocytosis mechanisms of nanoparticles is essential for safe and efficient therapeutic application. In particular, exocytosis is of significance in the removal of nanoparticles with drugs and contrast agents from the body, while endocytosis is of great importance for the targeting of nanoparticles in disease sites. Here, we review the recent research on the endocytosis and exocytosis of functionalized nanoparticles based on various sizes, shapes, and surface chemistries. We believe that this review contributes to the design of safe nanoparticles that can efficiently enter and leave human cells and tissues.Keywords: drug delivery, endocytosis, exocytosis, cancer cell, macrophage, nanoparticle, toxicity

High-frequency measurements of the partial pressure of CO2 (pCO2) are crucial in elucidating spatiotemporal dynamics of CO2 evasion from inland water systems and their role in the global carbon cycle. However, direct measurements of pCO2 are scarce, and the currently used measurement systems have not been compared for long-term deployment under various field conditions. A literature review was combined with laboratory and field tests to evaluate the application potential of three widely used automated equilibration systems, including spray- and marble-type equilibrators and a membrane-enclosed CO2 sensor, to continuous long-term or underway pCO2 measurements in an urbanized river system in Korea. Both equilibrators had a shorter response time than the membrane-enclosed sensor, well capturing large spatial variations of pCO2 during a transect study along a highly urbanized river reach. The membrane-enclosed sensor based on passive equilibration provided comparable underway measurements for the same river reach until pCO2 approached the upper detection limit of the sensor. The membrane-enclosed sensor deployed in a eutrophic river site could detect large temporal variations of pCO2 over several weeks. To tackle biofouling on the membrane that can reduce sensor accuracy over time, we suggest that antifouling measures, such as copper-mesh screening, be used for long-term deployments with maintenance intervals ranging from several days to weeks. The overall results suggest that the equilibrators are better suited for relatively short underway measurements than long-term deployment, whereas the membrane-enclosed sensor can be used for both the underway and long-term continuous measurements if the sensor has a proper detection range and can be protected by a biofouling-resistant covering. [ABSTRACT FROM AUTHOR]

This study examined the effects of Maillard reaction products (MRP) and MRP fermented by lactic acid bacteria on antioxidants and their enhancement of cardiovascular health in ICR mouse and rat models. In previous in vitro studies, the selected lactic acid bacteria were shown to significantly affect the activity of MRP. The expression of genes (e.g., superoxide dismutase, catalase, and glutathione peroxidase) related to antioxidant activity was upregulated by Maillard-reacted sodium caseinate (cMRP), and cMRP fermented by Lactobacillus fermentum H9 (F-cMRP) synergistically increased the expression of catalase and superoxide dismutase when compared with the high-cholesterol-diet group. Bleeding time, the assay for determination of antithrombotic activity, was significantly prolonged by Maillard-reacted whey protein concentration (wMRP) and wMRP fermented by Lactobacillus gasseri H10 (F-wMRP), similar to the bleeding time of the aspirin group (positive control). In addition, the acute pulmonary thromboembolism-induced mice overcame severe body paralysis or death in both the wMRP and the F-wMRP groups. In the serum-level experiment, cMRP and F-cMRP significantly reduced the serum total and low-density lipoprotein cholesterol levels and triglycerides but had only a slight effect on high-density lipoprotein cholesterol. The levels of aspartate transaminase and alanine transaminase also declined in the cMRP and F-cMRP intake groups compared with the high-cholesterol-diet group. In particular, F-cMRP showed the highest reducing effects on triglycerides, aspartate transaminase, and alanine transaminase. Moreover, the expression of cholesterol-related genes in the F-cMRP group demonstrated greater effects than for the cMRP group in the level of cholesterol 7 α-hydroxylase (CYP7A1), 3-hydroxy-3-methylglutaryl-CoA reductase (HMGR), and low-density lipoprotein receptors compared with the high-cholesterol-diet group. The protective role of cMRP and F-cMRP in the high-cholesterol group may have been the result of an antioxidative defense mechanism that regulated cholesterol synthesis and metabolism. Therefore, F-cMRP and cMRP have the potential to play preventive and therapeutic roles in the management of cardiovascular disease. [ABSTRACT FROM AUTHOR]

Optical measurements using ultra-violet/visible (UV/Vis) spectrophotometric sensors and fluorescent dissolved organic matter (FDOM) sensors have recently been used as proxies of dissolved organic carbon (DOC) concentrations of streams and rivers at high temporal resolution. Despite of the merits of the sensors, temperature changes and particulate matter in water can interfere the sensor readings, over-or under-estimating DOC concentrations. However, little efforts have been made to compare responses of the two types of the sensors in natural conditions. We conducted both laboratory ex¬periments and in situ monitoring with a UV/Vis sensor and a FDOM sensor during the three storm events in the fall of 2012 and the spring of 2013 in a forest stream in Korea in order to compare their performance. Laboratory experiments using the Suwannee River natural organic matter, humic acid, and fulvic acid demonstrated strong linear relationships between both the sensor signals and measured DOC concentrations with R² ≥ 0.98. Although temperature compensation might not be needed for the UV/Vis sensor, it was sensitive to relativley small changes in turbidity. In contrast, the FDOM sensor was insenstive to relatively low turbidity while the FDOM sensor outputs de¬creased significantly as temperature increased, requiring temperature compensated FDOM (e.g. FDOM20 for 20°C) for in situ monitoring of DOC. The results suggest that both sensors can be employed as a proxy for stream DOC concentrations after temperature and turbidity compensation in a forest stream where terrestrially derived humic-like materials are dominant components. [ABSTRACT FROM AUTHOR]