Preparation and Characterization of Carbohydrate-Functionalized Nanomaterials for Use as Cellular Probes and Targeted Delivery Vehicles

Carbohydrates are the most abundant biomolecules found in living organisms. In addition to their roles such as fuel storage and structural components, carbohydrates encode molecular recognition information. Carbohydrates presented on the cell surface interact with cell surface receptors. These carbohydrate-receptor interactions are involved in a variety of biological processes including intercellular adhesion, microbial attachment, and signal transduction. Research in the DeShong laboratory has been focused on the development of cellular probes and targeted delivery vehicles utilizing carbohydrate-cell surface receptor interactions. The work reported herein details (1) the synthesis of glycoconjugates to functionalize the surface of gold, silica, nanoparticles, and surfactant vesicles, and (2) the preparation and characterization of carbohydrate-functionalized gold nanospheres and surfactant vesicles. A variety of N-linked glycoconjugates tethered to thiols, siloxanes, and hydrocarbons were synthesized via modified Staudinger methodology with a high stereoselectivity. The stereochemistry at the anomeric center (alpha vs. beta) was readily controlled by choosing the appropriate reaction conditions. Typically, the alpha-stereochemistry arose from the reaction of ester derivatives with isoxazolines generated in-situ via epimerization of beta-phosphorimines at high temperature. The ability to control tether length has been demonstrated. Carbohydrate-functionalized gold nanospheres were prepared by two methods: (1) in-situ reduction of gold salt in the presence of thiolated glycoconjugates to provide ca. 2 nm particles and (2) a stepwise method where thiolated glycoconjugates were self-assembled on the surface of pre-formed, citrate-capped gold nanospheres to provide nanospheres with larger diameters (15 - 73 nm). Carbohydrate-functionalized surfactant vesicles were prepared by mixing a cationic surfactant cetyltrimethylammonium tosylate (CTAT) and an anionic surfactant sodium dodecylbenzenesulfonate (SDBS) in the presence of lipidated glycoconjugates. The resulting surfactant vesicles were stable, in mean diameter of ca. 140 nm, and showed significant amounts of glycoconjugate incorporation. The bioactivity of carbohydrates on the surface of gold nanospheres and surfactant vesicles was investigated through agglutination assays using carbohydrate-binding lectins concanavalin A and peanut agglutinin. These agglutination results indicated that both gold nanospheres and surfactant vesicles display multiple presentations of carbohydrates on their surfaces that can be used for binding of receptors. The suitability of the resulting glycosylated nanomaterials for use as cellular probes and targeted delivery vehicles is being investigated

A lab-on-a-disc platform enables serial monitoring of individual CTCs associated with tumor progression during EGFR-targeted therapy for patients with NSCLC

Rationale: Unlike traditional biopsy, liquid biopsy, which is a largely non-invasive diagnostic and monitoring tool, can be performed more frequently to better track tumors and mutations over time and to validate the efficiency of a cancer treatment. Circulating tumor cells (CTCs) are considered promising liquid biopsy biomarkers; however, their use in clinical settings is limited by high costs and a low throughput of standard platforms for CTC enumeration and analysis. In this study, we used a label-free, high-throughput method for CTC isolation directly from whole blood of patients using a standalone, clinical setting-friendly platform. Methods: A CTC-based liquid biopsy approach was used to examine the efficacy of therapy and emergent drug resistance via longitudinal monitoring of CTC counts, DNA mutations, and single-cell-level gene expression in a prospective cohort of 40 patients with epidermal growth factor receptor (EGFR)-mutant non-small cell lung cancer. Results: The change ratio of the CTC counts was associated with tumor response, detected by CT scan, while the baseline CTC counts did not show association with progression-free survival or overall survival. We achieved a 100% concordance rate for the detection of EGFR mutation, including emergence of T790M, between tumor tissue and CTCs. More importantly, our data revealed the importance of the analysis of the epithelial/mesenchymal signature of individual pretreatment CTCs to predict drug responsiveness in patients. Conclusion: The fluid-assisted separation technology disc platform enables serial monitoring of CTC counts, DNA mutations, as well as unbiased molecular characterization of individual CTCs associated with tumor progression during targeted therapy

Construction cost estimation using a case-based reasoning hybrid genetic algorithm based on local search method

Estimates of project costs in the early stages of a construction project have a significant impact on the operator\u27s decision-making in essential matters, such as the site\u27s decision or the construction period. However, it is not easy to carry out the initial stage with confidence, because information such as design books and specifications is not available. In previous studies, case-based reasoning (CBR) is used to estimate initial construction costs, and genetic algorithms are used to calculate the weight of the retrieve phase in CBR\u27s process. However, it is difficult to draw a better solution than the current one, because existing genetic algorithms use random numbers. To overcome these limitations, we reflect correlation numbers in the genetic algorithms by using the method of local search. Then, we determine the weights using a hybrid genetic algorithm that combines local search and genetic algorithms. A case-based reasoning model was developed using a hybrid genetic algorithm. Then, the model was verified with construction cost data that were not used for the development of the model. As a result, it was found that the hybrid genetic algorithm and case-based reasoning applied with the local search performed better than the existing solution. The detail mean error value was found to be 3.52%, 6.15%, and 0.33% higher for each case than the previous one

Camera for QUasars in EArly uNiverse (CQUEAN)

We describe the overall characteristics and the performance of an optical CCD camera system, Camera for QUasars in EArly uNiverse (CQUEAN), which is being used at the 2.1 m Otto Struve Telescope of the McDonald Observatory since 2010 August. CQUEAN was developed for follow-up imaging observations of red sources such as high redshift quasar candidates (z >= 5), Gamma Ray Bursts, brown dwarfs, and young stellar objects. For efficient observations of the red objects, CQUEAN has a science camera with a deep depletion CCD chip which boasts a higher quantum efficiency at 0.7 - 1.1 um than conventional CCD chips. The camera was developed in a short time scale (~ one year), and has been working reliably. By employing an auto-guiding system and a focal reducer to enhance the field of view on the classical Cassegrain focus, we achieve a stable guiding in 20 minute exposures, an imaging quality with FWHM >= 0.6" over the whole field (4.8' * 4.8'), and a limiting magnitude of z = 23.4 AB mag at 5-sigma with one hour total integration time.Comment: Accepted for publication in PASP. 26 pages including 5 tables and 24 figure

A microfluidic chip for screening individual cancer cells via eavesdropping on autophagyinducing crosstalk in the stroma niche

Autophagy is a cellular homeostatic mechanism where proteins and organelles are digested and recycled to provide an alternative source of building blocks and energy to cells. The role of autophagy in cancer microenvironment is still poorly understood. Here, we present a microfluidic system allowing monitoring of the crosstalk between single cells. We used this system to study how tumor cells induced autophagy in the stromal niche. Firstly, we could confirm that transforming growth factor beta 1 (TGF beta 1) secreted from breast tumor cells is a paracrine mediator of tumor-stroma interaction leading to the activation of autophagy in the stroma component fibroblasts. Through proof of concept experiments using TGF beta 1 as a model factor, we could demonstrate real time monitoring of autophagy induction in fibroblasts by single tumor cells. Retrieval of individual tumor cells from the microfluidic system and their subsequent genomic analysis was possible, allowing us to determine the nature of the factor mediating tumor-stroma interactions. Therefore, our microfluidic platform might be used as a promising tool for quantitative investigation of tumor-stroma interactions, especially for and high-throughput screening of paracrine factors that are secreted from heterogeneous tumor cell populations

Diquarks and the production of charmed baryons

Utilizing a quark model characterized by parameters that effectively replicate the masses of ground state hadrons, we illustrate that $(us)$ or $(ds)$ diquarks exhibit greater compactness in comparison to $(ud)$ diquarks. Concretely, the binding energy of the $(us)$ diquark - defined as the diquark's mass minus the combined masses of its individual quarks - is found to be more attractive than that of the $(ud)$ diquark. This heightened attraction present in $(us)$ diquarks could lead to enhanced production of $\Xi_c/D$ particles in high-energy pp or ultrarelativistic heavy-ion collisions.Comment: 9 pages, 5 figure

Dehydrated aqueous two-phase system micro-domains retain their shape upon rehydration to allow patterned reagent delivery to cells

Aqueous reagent solution micro-domains with sharp boundaries and defined shapes are created over cell monolayers within an immiscible bulk aqueous phase through rehydration of freestanding and portable dried reagent patches of the corresponding shape. This is in contrast to typical dissolution of reagent tablets or lyophilized biopolymer patches in aqueous solutions where no discernible reagent solution patterns are formed upon their full hydration. The key to enable the engineering of such stable reagent solution micro-domains is to formulate the reagent patches with polymers that form an aqueous two-phase system (ATPS) upon hydration by the bulk aqueous phase. This paper demonstrates this concept using dried reagent patches that incorporate dextran (DEX) and a bulk aqueous phase comprised of cell culture medium containing poly(ethylene) glycol (PEG). For reagents that prefer to partition in the DEX phase of the resulting ATPS, this procedure results in micro-patterned localization of reagent solution only to regions of the cell monolayer covered with the rehydrated DEX patch. The types of aqueous reagent solution micro-domain shapes that can be formed by the rehydration of such freestanding DEX-reagent patches are surprisingly broad and can be readily controlled by use of different templates for dehydrating the DEX solutions or even by cutting flat patches. The utility of the method is demonstrated through localized delivery of fluorescent molecules and enzymes for cell detachment. The patterned enzymatic detachment of cells enables convenient wound healing assays where cell monolayers can be wounded in different shapes dictated by the silhouette of the original DEX-reagent patchesclose1

Detection of EGFR Mutations Using Bronchial Washing-Derived Extracellular Vesicles in Patients with Non-Small-Cell Lung Carcinoma

The detection of epidermal growth factor receptor (EGFR) mutation, based on tissue biopsy samples, provides a valuable guideline for the prognosis and precision medicine in patients with lung cancer. In this study, we aimed to examine minimally invasive bronchial washing (BW)-derived extracellular vesicles (EVs) for EGFR mutation analysis in patients with lung cancer. A lab-on-a-disc equipped with a filter with 20-nm pore diameter, Exo-Disc, was used to enrich EVs in BW samples. The overall detection sensitivity of EGFR mutations in 55 BW-derived samples was 89.7% and 31.0% for EV-derived DNA (EV-DNA) and EV-excluded cell free-DNA (EV-X-cfDNA), respectively, with 100% specificity. The detection rate of T790M in 13 matched samples was 61.5%, 10.0%, and 30.8% from BW-derived EV-DNA, plasma-derived cfDNA, and tissue samples, respectively. The acquisition of T790M resistance mutation was detected earlier in BW-derived EVs than plasma or tissue samples. The longitudinal analysis of BW-derived EVs showed excellent correlation with the disease progression measured by CT images. The EGFR mutations can be readily detected in BW-derived EVs, which demonstrates their clinical potential as a liquid-biopsy sample that may aid precise management, including assessment of the treatment response and drug resistance in patients with lung cancer

Socioeconomic inequalities in obesity among Korean women aged 19-79 years: the 2016 Korean Study of Women’s Health-Related Issues

OBJECTIVES While the prevalence of obesity in Asian women has remained stagnant, studies of socioeconomic inequalities in obesity among Asian women are scarce. This study aimed to examine the recent prevalence of obesity in Korean women aged between 19 years and 79 years and to analyze socioeconomic inequalities in obesity. METHODS Data were derived from the 2016 Korean Study of Women’s Health-Related Issues. The chi-square test and logistic regression analysis were used to analyze the associations between socioeconomic factors and obesity using Asian standard body mass index (BMI) categories: low (<18.5 kg/m2 ), normal (18.5-22.9 kg/m2 ), overweight (23.0-24.9 kg/m2 ), and obese (≥25.0 kg/ m2 ). As inequality-specific indicators, the slope index of inequality (SII) and relative index of inequality (RII) were calculated, with adjustment for age and self-reported health status. RESULTS Korean women were classified into the following BMI categories: underweight (5.3%), normal weight (59.1%), overweight (21.2%), and obese (14.4%). The SII and RII revealed substantial inequalities in obesity in favor of more urbanized women (SII, 4.5; RII, 1.4) and against of women who were highly educated (SII, -16.7; RII, 0.3). Subgroup analysis revealed inequalities in obesity according to household income among younger women and according to urbanization among women aged 65-79 years. CONCLUSIONS Clear educational inequalities in obesity existed in Korean women. Reverse inequalities in urbanization were also apparent in older women. Developing strategies to address the multiple observed inequalities in obesity among Korean women may prove essential for effectively reducing the burden of this disease