Perforated Microcapsules with Selective Permeability Created by Confined Phase Separation of Polymer Blends

Semipermeable microcapsules have a great potential in controlled release of drugs, protection of catalysts, and immunoisolation of cells. However, a method to create such microcapsules with precisely controlled cutoff value and high mechanical stability remains an important challenge. Herein we report microfluidic approach to create microcapsules with size-selective permeability using phase separation of polymer blends in ultrathin middle layer of double-emulsion drops. The blend strongly confined in two-dimensional space exhibit local phase separation, instead of global separation. This enables the perforation of microcapsule membrane by selectively removing one of the phase-separated polymeric domains. The resultant monolithic membrane has uniform pores which connect the interior and the exterior of the microcapsules, thereby providing size-selective permeability. The pore size can be precisely tuned by regulating the extent of phase separation; this enables the control of cutoff value for permeation

Anisotropic Microparticles Created by Phase Separation of Polymer Blends Confined in Monodisperse Emulsion Drops

Anisotropic microparticles are promising as a new class of colloidal or granular materials due to their advanced functionalities which are difficult to achieve with isotropic particles. However, synthesis of the anisotropic microparticles with a highly controlled size and shape still remains challenging, despite their intense demands. Here, we report a microfluidic approach to create uniform anisotropic microparticles using phase separation of polymer blends confined in emulsion drops. Two different polymers are homogeneously dissolved in organic solvent at low concentration, which is microfluidically emulsified to produce oil-in-water emulsion drops. As the organic solvent diffuses out, small domains are formed in the emulsion drops, which are then merged, forming only two distinct domains. After the drops are fully consolidated, uniform anisotropic microparticles with two compartments are created. The shape of the resulting microparticles is determined by combination of a pair of polymers and type of surfactant. Spherical microparticles with eccentric core and incomplete shell are prepared by consolidation of polystyrene (PS) and poly­(lactic acid) (PLA), and microparticles with single crater are formed by consolidation of PS and poly­(methyl methacrylate) (PMMA); both emulsions are stabilized with poly­(vinyl alcohol) (PVA). With surfactants of triblock copolymer, acorn-shaped Janus microparticles are obtained by consolidating emulsion drops containing PS and PLA. This microfluidic production of anisotropic particles can be further extended to any combination of polymers and colloids to provide a variety of structural and chemical anisotropy

Anisotropic Microparticles Created by Phase Separation of Polymer Blends Confined in Monodisperse Emulsion Drops

Anisotropic microparticles are promising as a new class of colloidal or granular materials due to their advanced functionalities which are difficult to achieve with isotropic particles. However, synthesis of the anisotropic microparticles with a highly controlled size and shape still remains challenging, despite their intense demands. Here, we report a microfluidic approach to create uniform anisotropic microparticles using phase separation of polymer blends confined in emulsion drops. Two different polymers are homogeneously dissolved in organic solvent at low concentration, which is microfluidically emulsified to produce oil-in-water emulsion drops. As the organic solvent diffuses out, small domains are formed in the emulsion drops, which are then merged, forming only two distinct domains. After the drops are fully consolidated, uniform anisotropic microparticles with two compartments are created. The shape of the resulting microparticles is determined by combination of a pair of polymers and type of surfactant. Spherical microparticles with eccentric core and incomplete shell are prepared by consolidation of polystyrene (PS) and poly­(lactic acid) (PLA), and microparticles with single crater are formed by consolidation of PS and poly­(methyl methacrylate) (PMMA); both emulsions are stabilized with poly­(vinyl alcohol) (PVA). With surfactants of triblock copolymer, acorn-shaped Janus microparticles are obtained by consolidating emulsion drops containing PS and PLA. This microfluidic production of anisotropic particles can be further extended to any combination of polymers and colloids to provide a variety of structural and chemical anisotropy

Controlling Smectic Liquid Crystal Defect Patterns by Physical Stamping-Assisted Domain Separation and Their Use as Templates for Quantum Dot Cluster Arrays

Controlling the organization of self-assembling building blocks over a large area is crucial for lithographic tools based on the bottom-up approach. However, the fabrication of liquid crystal (LC) defect patterns with a particular ordering still remains a challenge because of the limited close-packed morphologies of LC defects. Here, we introduce a multiple-stamping domain separation method for the control of the dimensions and organization of LC defect structures. Prepatterns with various grid shapes on planar polyimide (PI) surfaces were fabricated by pressing a line-shaped stamp into the PI surfaces in two different directions, and then these surfaces were used to prepare LC defect structures confined to these grid domains. The dimensions of the LC defect structures, namely, the equilibrium diameter and the center to center spacing, are controlled by varying the line spacing of the stamps and the film thickness. A variety of arrangements of LC defects, including square, rhombic, hexagonal, and other oblique lattices, can be obtained by simply varying the stamping angle (Ω) between the first and second stamping directions. Furthermore, we demonstrate that the resulting controllable LC defect arrays can be used as templates for generating various patterns of nanoparticle clusters by trapping quantum dots (QDs) within the cores of the LC defects

Data_Sheet_2_Long-term survival benefits of intrathecal autologous bone marrow-derived mesenchymal stem cells (Neuronata-R®: lenzumestrocel) treatment in ALS: Propensity-score-matched control, surveillance study.docx

ObjectiveNeuronata-R® (lenzumestrocel) is an autologous bone marrow-derived mesenchymal stem cell (BM-MSC) product, which was conditionally approved by the Korean Ministry of Food and Drug Safety (KMFDS, Republic of Korea) in 2013 for the treatment of amyotrophic lateral sclerosis (ALS). In the present study, we aimed to investigate the long-term survival benefits of treatment with intrathecal lenzumestrocel.MethodsA total of 157 participants who received lenzumestrocel and whose symptom duration was less than 2 years were included in the analysis (BM-MSC group). The survival data of placebo participants from the Pooled-Resource Open-Access ALS Clinical Trials (PROACT) database were used as the external control, and propensity score matching (PSM) was used to reduce confounding biases in baseline characteristics. Adverse events were recorded during the entire follow-up period after the first treatment.ResultsSurvival probability was significantly higher in the BM-MSC group compared to the external control group from the PROACT database (log-rank, p ConclusionThe results of the present study showed that lenzumestrocel treatment had a long-term survival benefit in real-world ALS patients.</p

Socioeconomic Burden of Influenza in the Republic of Korea, 2007–2010

<div><p>Background</p><p>Although the socioeconomic burden of 2009 pandemic influenza A (H1N1) was considerable, no reliable estimates have been reported. Our aim was to compared medical costs and socioeconomic burden resulting from pandemic influenza A (H1N1) 2009 with that of previous seasonal influenza.</p><p>Methods</p><p>We estimated the medical costs and socioeconomic burden of influenza from May 2007 to April 2010. We used representative national data sources(data from the Health Insurance Review Agency, the National Health Insurance Corporation, the Korea Centers for Disease Control and Prevention, and the Korean National Statistics Office) including medical utilization, prescription of antivirals, and vaccination. Uncertainty of data was explored through sensitivity analysis using Monte Carlo simulation.</p><p>Results</p><p>Compared with the seasonal influenza, total medical costs (US$291.7 million) associated with pandemic (H1N1) 2009 increased more than 37-fold. Compared with the 2007–2008 season, outpatient diagnostic costs (US$135.3 million) were 773 times higher in the 2009–2010 season, and the mean diagnostic cost per outpatient visit was 58.8 times higher. Total socioeconomic burden of pandemic (H1N1) 2009 was estimated at US$1581.3 million (10$1436.0–1808.3 million) and those of seasonal influenza was estimated at US$44.7 million (10$32.4–57.9 million) in 2007–2008 season and US$42.3 million (10$31.5–53.8 million) in 2008–2009 season. Indirect costs accounted for 56.0% of total costs in pandemic (H1N1) 2009, and 66.48–68.09% in seasonal influenza. The largest contributors to total burden were productivity losses of caregiver in pandemic (H1N1) 2009, and productivity losses due to morbidity of outpatient in seasonal influenza.</p><p>Conclusions</p><p>In the Republic of Korea, socioeconomic burden of pandemic (H1N1) 2009 were considerably higher than burden of the previous two influenza seasons, primarily because of high diagnostic costs and longer sick leave.</p></div

Estimating Costs of Illness for Pandemic Influenza A (H1N1) 2009 and Seasonal Influenza in the Republic of Korea, 2007–2010.

<p>NA: not available Costs are expressed as fixed value or median value (range, 10%–90%).</p

Outbreak of Pandemic Influenza A (H1N1) 2009 and Main Response Strategy in Korea.

<p>Outbreak of Pandemic Influenza A (H1N1) 2009 and Main Response Strategy in Korea.</p

Number of Visits and Medical Costs for Influenza in the Republic of Korea, 2007–2010.

<p>*P-values for proportional difference of subcategories of medical costs across seasons were determined by chi-square tests, and P-values for mean difference of costs per visit across seasons were determined by analysis of variance.</p><p>Results are expressed as mean ± standard deviation.</p