Synthesis of Cell-Adhesive Anisotropic Multifunctional Particles by Stop Flow Lithography and Streptavidin–Biotin Interactions

Cell-adhesive particles are of significant interest in biotechnology, the bioengineering of complex tissues, and biomedical research. Their applications range from platforms to increase the efficiency of anchorage-dependent cell culture to building blocks to loading cells in heterogeneous structures to clonal-population growth monitoring to cell sorting. Although useful, currently available cell-adhesive particles can accommodate only homogeneous cell culture. Here, we report the design of anisotropic hydrogel microparticles with tunable cell-adhesive regions as first step toward micropatterned cell cultures on particles. We employed stop flow lithography (SFL), the coupling reaction between amine and N-hydroxysuccinimide (NHS) and streptavidin–biotin chemistry to adjust the localization of conjugated collagen and poly-l-lysine on the surface of microscale particles. Using the new particles, we demonstrate the attachment and formation of tight junctions between brain endothelial cells. We also demonstrate the geometric patterning of breast cancer cells on particles with heterogeneous collagen coatings. This new approach avoids the exposure of cells to potentially toxic photoinitiators and ultraviolet light and decouples in time the microparticle synthesis and the cell culture steps to take advantage of the most recent advances in cell patterning available for traditional culture substrates.National Institutes of Health (U.S.) (GM092804)National Science Foundation (U.S.) (CMMI-1120724 and DMR-1006147)Samsung Scholarship Foundatio

Advanced Telecommunications and Signal Processing Program

Contains an introduction and reports on seven research projects.Advanced Telecommunications Research ProgramAT&T FellowshipGEM FellowshipU.S. Federal Bureau of InvestigationLucent Technologies FellowshipCharles S. Draper LaboratoryU.S. Navy - Office of Naval Research NDSEG Graduate Fellowshi

Direct electrophoretic microRNA preparation from clinical samples using nanofilter membrane

A method to directly collect negatively charged nucleic acids, such as DNA and RNA, in the biosamples simply by applying an electric field in between the sample and collection buffer separated by the nanofilter membrane is proposed. The nanofilter membrane was made of low-stress silicon nitride with a thickness of 100 nm, and multiple pores were perforated in a highly arranged pattern using nanoimprint technology with a pore size of 200 nm and a pore density of 7.22 × 108/cm2. The electrophoretic transport of hsa-mir-93-5p across the membrane was confirmed in pure microRNA (miRNA) mimic solution using quantitative reverse transcription-polymerase chain reactions (qRT-PCR). Consistency of the collected miRNA quantity, stability of the system during the experiment, and yield and purity of the prepared sample were discussed in detail to validate the effectiveness of the electrical protocol. Finally, in order to check the applicability of this method to clinical samples, liquid biopsy process was demonstrated by evaluating the miRNA levels in sera of hepatocellular carcinoma patients and healthy controls. This efficient system proposed a simple, physical idea in preparation of nucleic acid from biosamples, and demonstrated its compatibility to biological downstream applications such as qRT-PCR as the conventional nucleic acid extraction protocols.This work was supported by BioNano Health-Guard Research Center funded by the Ministry of Science and ICT (MSIT) of Korea as Global Frontier Project (2013M3A6B2078943), the Nano Material Technology Development Program through the National Research Foundation of Korea (NRF) funded by Ministry of Science and ICT (MSIT) of Korea (2015M3A7B4050454), and (2019R1A2C2005783)

Determination of an Applicable FRAX Model in Korean Women

We investigated which of the three FRAX fracture risk assessment tool models is most applicable to Korean women. For 306 postmenopausal women (mean age, 77 yr) with a hip fracture, fracture probabilities were calculated using FRAX models from Japan, Turkey and China. Data on bone mineral density (BMD) at the femoral neck were available for 103 patients. Significant differences existed among the models, independent of the inclusion of BMD in the calculation of fracture probabilities. The probabilities of both major osteoporotic fractures and hip fractures were significantly higher in the Japanese model than in the Turkish or Chinese models. In all of the models, the probabilities of a major osteoporotic fracture, but not of a hip fracture, decreased significantly if calculated without BMD values. By applying the Japanese model, the ten-year probabilities for major osteoporotic and hip fractures increased significantly with age. Our results suggest that the Japanese FRAX model might be the most appropriate for Korean women

Perioperative Risk of Hip Arthroplasty in Patients with Cirrhotic Liver Disease

We retrospectively reviewed the complete medical records of 30 patients with a diagnosis of liver cirrhosis who had undergone hip arthroplasty at three academic institutions between October 1994 and May 2001. There were 26 males and 4 females with a mean age of 60 yr at index operation. Surgical procedures included 17 primary total hip arthroplasties (THA), 8 bipolar hemiarthroplasties, and 5 revision THAs. According to the Child-Pugh scoring system, 19 cirrhotic patients were categorized as class A, 9 as class B, and 2 as class C. Eight (26.7%) of the 30 patients had one or more perioperative complications. Of these, wound infection was the most common, with a rate of 10% (3 of 30 hips). Other perioperative complications included surgical site bleeding, coagulopathy, encephalopathy, gastrointestinal bleeding, pneumonia, and arrhythmia. Death occurred in 2 (6.7%) of the 30 patients; both were Child-Pugh's C cirrhotics. A higher Child-Pugh score (p=0.0001) and a high level of creatinine (p=0.0499) were associated with significantly increased perioperative complications or death. Our findings suggest that surgeons should be vigilant about perioperative complications in patients with advanced cirrhotic liver disease who undergo hip arthroplasty, albeit the mortality rates are relatively low in less severe cirrhotics

Machine learning-based prediction of post-stroke cognitive status using electroencephalography-derived brain network attributes

ObjectivesMore than half of patients with acute ischemic stroke develop post-stroke cognitive impairment (PSCI), a significant barrier to future neurological recovery. Thus, predicting cognitive trajectories post-AIS is crucial. Our primary objective is to determine whether brain network properties from electroencephalography (EEG) can predict post-stroke cognitive function using machine learning approach.MethodsWe enrolled consecutive stroke patients who underwent both EEG during the acute stroke phase and cognitive assessments 3 months post-stroke. We preprocessed acute stroke EEG data to eliminate low-quality epochs, then performed independent component analysis and quantified network characteristics using iSyncBrain®. Cognitive function was evaluated using the Montreal cognitive assessment (MoCA). We initially categorized participants based on the lateralization of their lesions and then developed machine learning models to predict cognitive status in the left and right hemisphere lesion groups.ResultsEighty-seven patients were included, and the accuracy of lesion laterality prediction using EEG attributes was 97.0%. In the left hemispheric lesion group, the network attributes of the theta band were significantly correlated with MoCA scores, and higher global efficiency, clustering coefficient, and lower characteristic path length were associated with higher MoCA scores. Most features related to cognitive scores were selected from the frontal lobe. The predictive powers (R-squared) were 0.76 and 0.65 for the left and right stroke groups, respectively.ConclusionEstimating EEG-based network properties in the acute phase of ischemic stroke through a machine learning model has a potential to predict cognitive outcomes after ischemic stroke

Acute Toxicity and General Pharmacological Action of QGC EXT

It has been shown that QGC isolated and purified from Rumecis folium found protective effects of gastritis and esophagitis which EXT is an ethanol extract of it. We examined acute toxicity and the general pharmacological action of QGC EXT to search for any side effects of it in rats, mice, guinea pigs, and cats. In a single dose toxicity study, QGC EXT didn't show toxicological effects in rats and mice, and the LD50 was over 5 g/kg in both animals, and there were also no changes in weight, feed and water intake during these toxicological experimental periods. We examined the general pharmacological action on central controlled behavior responses, and peripheral organs including blood pressure, heart rate, respiration and gastrointestinal system, We found that there were no significant changes in body temperature, locomotors activity, stereotyped behaviors, sleeping time, and convulsion. In other studies, writhing reaction, normal body temperature, there did not appear to be any changes. The large intestine movement and electrical field stimulation-induced contraction was not changes by its EXT. In addition, the influences on blood pressure, heart rates, and respiration by QGC EXT were not found. These results indicate that QGC EXT may be very safe as a new drug, since its LD50 was very high over 5 g/kg and any side effects were not found