A case of coronary artery compression syndrome resulting from peri-valvular regurgitation and long-standing atrial fibrillation.

A man in his 70s with a history of mitral valve replacement (MVR) and long-standing persistent atrial fibrillation (AF) presented with effort angina. Coronary angiography revealed severe stenosis of the left main coronary artery (LMCA). As it was an emergent case, PCI (percutaneous coronary intervention) was selected for treatment. Intravascular ultrasonography revealed no atherosclerotic lesions in the LMCA. The LMCA was effectively dilated by the drug-eluting stent. No elevation in intracardiac pressure was observed in cardiac catheterization after PCI. Computed tomography scan indicated potential compression of the LMCA by the surrounding structures. In cases of long-standing persistent AF and an enlarged atrium after MVR, the possibility of LMCA stenosis due to anatomical changes should be considered. Learning Objectives: ◾Peri-valvular regurgitation and long-standing persistent atrial fibrillation can potentially cause atrial enlargement.◾Coronary artery stenosis without atherosclerosis can occur due to compression from surrounding structures or shifting of the coronary artery.◾Stent therapy provides a temporary solution and coronary artery bypass grafting or switching should be considered if re-stenosis occurs.

Understanding the effects of ethanol on the liposome bilayer structure using microfluidic-based time-resolved small-angle X-ray scattering and molecular dynamics simulations.

Lipid nanoparticles (LNPs) are essential carrier particles in drug delivery systems, particularly in ribonucleic acid delivery. In preparing lipid-based nanoparticles, microfluidic-based ethanol injection may produce precisely size-controlled nanoparticles. Ethanol is critical in LNP formation and post-treatment processes and affects liposome size, structure, lamellarity, and drug-loading efficiency. However, the effects of time-dependent changes in the ethanol concentration on the structural dynamics of liposomes are not clearly understood. Herein, we investigated ethanol-induced lipid bilayer changes in liposomes on a time scale from microseconds to tens of seconds using a microfluidic-based small-angle X-ray scattering (SAXS) measurement system coupled with molecular dynamics (MD) simulations. The time-resolved SAXS measurement system revealed that single unilamellar liposomes were converted to multilamellar liposomes within 0.8 s of contact with ethanol, and the d-spacing was decreased from 6.1 (w/o ethanol) to 4.4 nm (80% ethanol) with increasing ethanol concentration. We conducted 1 µs MD simulations to understand the molecular-level structural changes in the liposomes. The MD simulations revealed that the changes in the lamellar structure caused by ethanol at the molecular level could explain the structural changes in the liposomes observed via time-resolved SAXS. Therefore, the post-treatment process to remove residual ethanol is critical in liposome formation.

Development of Polymer-Lipid Hybrid Nanoparticles for Large-Sized Plasmid DNA Transfection.

RNA and DNA delivery technologies using lipid nanoparticles (LNPs) have advanced significantly, as demonstrated by their successful application in mRNA vaccines. To date, commercially available RNA therapeutics include Onpattro, a 21 bp siRNA, and mRNA vaccines comprising 4300 nucleotides for COVID-19. However, a significant challenge remains in achieving efficient transfection, as the size of the delivered RNA and DNA increases. In contrast to RNA transfection, plasmid DNA (pDNA) transfection requires multiple steps, including cellular uptake, endosomal escape, nuclear translocation, transcription, and translation. The low transfection efficiency of large pDNA is a critical limitation in the development of artificial cells and their cellular functionalization. Here, we introduce polymer-lipid hybrid nanoparticles designed for efficient, large-sized pDNA transfection. We demonstrated that LNPs loaded with positively charged pDNA-polycation core nanoparticles exhibited a 4-fold increase in transfection efficiency for 15 kbp pDNA compared with conventional LNPs, which encapsulate a negatively charged pDNA-polycation core. Based on assessments of the size and internal structure of the polymer-lipid nanoparticles as well as hemolysis and cellular uptake analysis, we propose a strategy to enhance large-sized pDNA transfection using LNPs. This approach holds promise for accelerating the in vivo delivery of large-sized pDNA and advancing the development of artificial cells.

A portable liquid chromatography system based on a separation/detection chip module consisting of a replaceable ultraviolet-visible absorbance or contactless conductivity detection unit.

Recently, there has been a growing demand for miniaturized analytical instruments, including portable HPLC systems, that can enable rapid analysis in the field. This study aimed to develop chip-based separation/detection modules with replaceable detection units for constructing compact HPLC systems to minimize the dead volume. This module provides a tubing-free connection between the column and the detection unit. This study also built detection units for conductivity detection and ultraviolet-visible (UV-Vis) detection to cover a wide variety of inorganic and organic compounds. Furthermore, UV- and Vis-light-emitting diodes were employed for the absorbance detection unit. In addition, portable all-in-one HPLC systems and a handy HPLC system were constructed for ion chromatography and reversed-phase chromatography, demonstrating the successful separation and detection of inorganic ions and several organic compounds.

A case of retractable helix lead auto-retraction: A possible cause of deep septal lead dislodgement.

This paper explains the phenomenon where the helix lead automatically retracts because of residual torque during deep septal pacing.

Clinical impact of optical coherence tomography findings after drug-coated balloon treatment for patients with acute coronary syndromes.

BACKGROUND: Drug-coated balloon (DCB) became a potential treatment option for patients with acute coronary syndrome (ACS); however, factors associated with target lesion failure (TLF) remain uncertain. METHODS: This retrospective, multicentre, observational study included consecutive ACS patients who underwent optical coherence tomography (OCT)-guided DCB treatment. Patients were divided into two groups according to the occurrence of TLF, a composite of cardiac death, target vessel-related myocardial infarction, and ischemia-driven target lesion revascularisation. RESULTS: We enrolled 127 patients in this study. During the median follow-up period of 562 (IQR: 342-1164) days, 24 patients (18.9%) experienced TLF, and 103 patients (81.1%) did not. The cumulative 3-year incidence of TLF was 22.0%. The cumulative 3-year incidence of TLF was the lowest in patients with plaque erosion (PE) (7.5%), followed by those with rupture (PR) (26.1%) and calcified nodule (CN) (43.5%). Multivariable Cox regression analysis revealed that plaque morphology was independently associated with TLF on pre-PCI (percutaneous coronary intervention) OCT, and residual thrombus burden (TB) was positively associated with TLF on post-PCI OCT. Further stratification by post-PCI TB revealed a comparable incidence of TLF in patients with PR (4.2%) to that of PE if the culprit lesion had a smaller post-PCI TB than the cut-off value (8.4%). TLF incidence was high in patients with CN, regardless of TB size on post-PCI OCT. CONCLUSIONS: Plaque morphology was strongly associated with TLF for ACS patients after DCB treatment. Residual TB post-PCI might be a key determinant for TLF, especially in patients with PR.

Effect of Organic Solvents on a Production of PLGA-Based Drug-Loaded Nanoparticles Using a Microfluidic Device.

The translation of nanoparticles (NPs) from laboratory to clinical settings is limited, which is not ideal. One of the reasons for this is that we currently have limited ability to precisely regulate various physicochemical parameters of nanoparticles. This has made it difficult to rapidly perform targeted screening of drug preparation conditions. In this study, we attempted to broaden the range of preparation conditions for particle size-modulated poly(lactic-co-glycolic-acid) (PLGA) NP to enhance their applicability for drug delivery systems (DDS). This was done using a variety of organic solvents and a glass-based microfluidic device. Furthermore, we compared the PDMS-based microfluidic device to the glass-based microfluidic device in terms of the possibility of a wider range of preparation conditions, especially the effect of different solvents on the size of the PLGA NPs. PLGA NPs with different sizes (sub-200 nm) were successfully prepared, and three different types of taxanes were employed for encapsulation. The drug-loaded NPs showed size-dependent cytotoxicity in cellular assays, regardless of the taxane drug used.

Preparation of size-tunable sub-200 nm PLGA-based nanoparticles with a wide size range using a microfluidic platform.

The realization of poly (lactic-co-glycolic acid) nanoparticles (PLGA NPs) from laboratory to clinical applications remains slow, partly because of the lack of precise control of each condition in the preparation process and the rich selectivity of nanoparticles with diverse characteristics. Employing PLGA NPs to establish a large range of size-controlled drug delivery systems and achieve size-selective drug delivery targeting remains a challenge for therapeutic development for different diseases. In this study, we employed a microfluidic device to control the size of PLGA NPs. PLGA, poly (ethylene glycol)-methyl ether block poly (lactic-co-glycolide) (PEG-PLGA), and blend (PLGA + PEG-PLGA) NPs were engineered with defined sizes. Blend NPs exhibit the widest size range (40-114 nm) by simply changing the flow rate conditions without changing the precursor (polymer molecular weight, concentration, and chain segment composition). A model hydrophobic drug, paclitaxel (PTX), was encapsulated in the NPs, and the PTX-loaded NPs maintained a large range of controllable NP sizes. Furthermore, size-controlled NPs were used to investigate the effect of particle size of sub-200 nm NPs on tumor cell growth. The 52 nm NPs showed higher cell growth inhibition than 109 nm NPs. Our method allows the preparation of biodegradable NPs with a large size range without changing polymer precursors as well as the nondemanding fluid conditions. In addition, our model can be applied to elucidate the role of particle sizes of sub-200 nm particles in various biomedical applications, which may help develop suitable drugs for different diseases.

Impact of post physiological assessment after treatment for de novo coronary lesions using drug-coated balloons.

BACKGROUND: Acute physiological changes after balloon angioplasty are very important because of acute recoil and dissection. However, serial physiological assessments after drug-coated balloons (DCB) have not been investigated. METHODS: This prospective observational single-center study evaluated 50 lesions that underwent optical coherence tomography (OCT)-guided percutaneous coronary intervention (PCI) with DCB and a 9-months angiographical and OCT follow-up. Fractional flow reserve (FFR) and instantaneous wave-free ratio (iFR) were measured immediately (FFR0m and, iFR0m) and 15 min (FFR15m and iFR15m) after DCB, and the difference (dif-FFR and, dif-iFR) was calculated. The iFR gradients during lesions treated with DCB were measured. For OCT and quantitative coronary angiography (QCA) data, delta values were calculated. RESULTS: At index PCI, three lesions were needed for bailout stenting. At follow-up, 47 lesions were divided into two groups according to the delta minimal lumen area (MLA) on OCT: late lumen enlargement (LLE) (n = 29) and non-LLE (n = 18). In LLE group, FFR15m and iFR15m were significantly high (0.90 ± 0.03 vs. 0.85 ± 0.07, p < 0.001, 0.97 ± 0.02 vs. 0.92 ± 0.10, p = 0.008, respectively) and %AS on OCT, dif-FFR and dif-iFR were significantly low (38.5% (33.6, 42.3) vs. 45.1% (38.9, 54.6), p = 0.03, -0.001 ± 0.006 vs. 0.036 ± 0.032, p < 0.001, -0.002 ± 0.008 vs. 0.019 ± 0.017, p < 0.001, respectively) compared with non-LLE group. However, there were no significant differences in FFR0m, iFR0m, or any other OCT or QCA data. CONCLUSIONS: Post-physiological assessment and a decrease in physiological indices in the first 15 min after PCI are important for treating de novo lesions using the DCB strategy.

Non-competitive fluorescence polarization immunosensing for CD9 detection using a peptide as a tracer.

This paper is the first report of a non-competitive fluorescence polarization immunoassay (NC-FPIA) using a peptide as a tracer. The NC-FPIA can easily and quickly quantify the target after simply mixing them together. This feature is desirable for point-of-need applications such as clinical diagnostics, infectious disease screening, on-site analysis for food safety, etc. In this study, the NC-FPIA was applied to detect CD9, which is one of the exosome markers. We succeeded in detecting not only CD9 but also CD9 expressing exosomes derived from HeLa cells. This method can be applied to various targets if a tracer for the target can be prepared, and expectations are high for its future uses.

Production of siRNA-Loaded Lipid Nanoparticles using a Microfluidic Device.

The development of functional lipid nanoparticles (LNPs) is one of the major challenges in the field of drug delivery systems (DDS). Recently, LNP-based RNA delivery systems, namely, RNA-loaded LNPs have attracted attention for RNA therapy. In particular, mRNA-loaded LNP vaccines were approved to prevent COVID-19, thereby leading to the paradigm shift toward the development of next-generation nanomedicines. For the LNP-based nanomedicines, the LNP size is a significant factor in controlling the LNP biodistribution and LNP performance. Therefore, a precise LNP size control technique is indispensable for the LNP production process. Here, we report a protocol for size controlled LNP production using a microfluidic device, named iLiNP. siRNA loaded LNPs are also produced using the iLiNP device and evaluated by in vitro experiment. Representative results are shown for the LNP size, including siRNA-loaded LNPs, Z-potential, siRNA encapsulation efficiency, cytotoxicity, and target gene silencing activity.

Electrochemical enzyme-based blood ATP and lactate sensor for a rapid and straightforward evaluation of illness severity.

This study aimed to develop an electrochemical system for measuring blood ATP and lactate levels in a single format. The ratio of lactate to ATP levels was previously reported to provide an alternative illness severity score. Although severity evaluation is crucial to treat patients with acute disease admitted to intensive care units, no sensors are currently available to simply and rapidly measure ATP and lactate levels using the same detection method. Therefore, we constructed an integrated sensing system for ATP and lactate using enzymatic reactions and two sets of electrodes integrated into a chip connected to a single potentiostat operated by a microcontroller. The enzymatic system involves adenylate kinase, pyruvate kinase, and pyruvate oxidase for ATP, and lactate oxidase for lactate, both of which produce hydrogen peroxide. Multiplex enzyme-based reactions were designed to minimize the corresponding operations significantly without enzyme immobilization onto the electrodes. The system was robust in the presence of potentially interfering blood components, such as ascorbate, pyruvate, ADP, urate, and potassium ions. The ATP and lactate levels in the blood were successfully measured using the new sensor with good recoveries. The analytical results of blood samples obtained using our sensor were in good agreement with those using conventional methods. Integrating electrode-based analysis and a microcontroller-based system saved further operations, enabling the straightforward measurement of ATP and lactate levels within 5 min. The proposed sensor may serve as a useful tool in the management of serious infectious diseases.

Healed plaque erosion as a cause of recurrent vasospastic angina: a case report.

BACKGROUND: Recurrent vasospastic angina sometimes occurs. Fresh thrombi have been known to arise without plaque rupture at coronary spasm sites due to blood flow stagnation and intimal erosion caused by vasospasms. The relationship between recurrence of vasospastic angina and thrombus formation remains unclear. CASE SUMMARY: A 67-year-old man presented with sudden chest pain at rest. Electrocardiography and coronary angiography indicated vasospastic angina. His chest pain persisted despite the administration of benidipine, isosorbide mononitrate, nicorandil, and nifedipine. Coronary angiography performed one month after initial presentation showed stenosis refractory to isosorbide administration. Optical coherence tomography revealed a healed plaque, and a stent was deployed. The patient remained symptom-free at 1-year follow-up. DISCUSSION: Prolonged coronary vasospasm with limited coronary blood flow could induce total occlusion of the coronary artery, and acute thrombus formation, which resulted in healed plaque erosion. When vasospastic angina cannot be controlled, rapidly progressive stenosis caused by healed plaque erosion could be its underlying cause and mechanism. This report indicates that antiplatelet therapy may be a preventive option for future recurrent vasospastic angina, especially in those caused by healed plaques.

Facile and rapid detection of SARS-CoV-2 antibody based on a noncompetitive fluorescence polarization immunoassay in human serum samples.

Antibody detection methods for viral infections have received broad attention due to the COVID-19 pandemic. In addition, there remains an ever-increasing need to quantitatively evaluate the immune response to develop vaccines and treatments for COVID-19. Here, we report an analytical method for the rapid and quantitative detection of SARS-CoV-2 antibody in human serum by fluorescence polarization immunoassay (FPIA). A recombinant SARS-CoV-2 receptor binding domain (RBD) protein labeled with HiLyte Fluor 647 (F-RBD) was prepared and used for FPIA. When the anti-RBD antibody in human serum binds to F-RBD, the degree of polarization (P) increases by suppressing the rotational diffusion of F-RBD. The measurement procedure required only mixing a reagent containing F-RBD with serum sample and measuring the P value with a portable fluorescence polarization analyzer after 15 min incubation. We evaluated analytical performance of the developed FPIA system using 30 samples: 20 COVID-19 positive sera and 10 negative sera. The receiver operating characteristic curve drawn with the obtained results showed that this FPIA system had high accuracy for discriminating COVID-19 positive or negative serum (AUC = 0.965). The total measurement time was about 20 min, and the serum volume required for measurement was 0.25 µL. Therefore, we successfully developed the FPIA system that enables rapid and easy quantification of SARS-CoV-2 antibody. It is believed that our FPIA system will facilitate rapid on-site identification of infected persons and deepen understanding of the immune response to COVID-19.

Simple Approach for Fluorescence Signal Amplification Utilizing a Poly(vinyl alcohol)-Based Polymer Structure in a Microchannel.

Analytical methods with fluorescence detection are in widespread use for detecting low abundance analytes. Here, we report a simple method for fluorescence signal amplification utilizing a structure of an azide-unit pendant water-soluble photopolymer (AWP) in a microchannel. The AWP is a poly(vinyl alcohol)-based photocross-linkable polymer, which is often used in biosensors. We determined that the wall-like structure of the AWP (AWP-wall) constructed in a microchannel functioned as an amplifier of a fluorescence signal. When a solution of fluorescent molecules was introduced into the microchannel having the AWP-wall, the fluorescent molecules accumulated inside the AWP-wall by diffusion. Consequently, the fluorescence intensity inside the AWP-wall increased locally. Among the fluorescent molecules considered in this paper, 9H-(1,3-dichloro-9,9-dimethylacridin-2-one-7-yl) (DDAO) showed the highest efficiency of fluorescence signal amplification. We prepared a calibration curve for DDAO using the fluorescence intensity inside the AWP-wall, and the sensitivity was 5-fold that for the microchannel without the AWP-wall. This method realizes the improved sensitivity of fluorescence detection easily because the fluorescence signal was amplified only by injecting the solution into the microchannel having the AWP-wall. Furthermore, since this method is not limited to only the use of microchannel, we expect it to be applicable in various fields.

Dip-Type Paper-Based Analytical Device for Straightforward Quantitative Detection without Precise Sample Introduction.

The development of low-cost, user-friendly paper-based analytical devices (PADs) that can easily measure target chemicals is attracting attention. However, most PADs require manipulation of the sample using sophisticated micropipettes for quantitative analyses, which restricts their user-friendliness. In addition, immobilization of detection molecules to cellulose fibers is essential for achieving good measuring ability as it ensures the homogeneity of color development. Here, we have described a dip-type PAD that does not require pipette manipulation for sample introduction and immobilization of detection molecules to cellulose fibers and its application to ascorbic acid (AA) and pH assays. The PAD consisted of a dipping area and two channels, each with two detection zones. The developed PADs show color distribution in the two detection zones depending on the sample flow from the dipping area. In comparison with a PAD that has one detection zone at the end of the channel, our developed device achieved higher sensitivity (limit of detection (LOD), 0.22 mg/mL) and reproducibility (maximum coefficient of variation (CV), 2.4%) in AA detection. However, in pH detection, the reproducibility of the PAD with one detection zone at the end of the channel (maximum CV, 21%) was worse than that with two zones (maximum CV, 11%). Furthermore, a dipping time over 3 s did not affect color formation or calibration curves in AA detection: LODs at 3 and 30 s dipping time were 18 and 5.8 µg/mL, respectively. The simultaneous determination of AA and pH in various beverages was performed with no significant difference compared to results of the conventional method.