Efficacy and Safety of Sirolimus-Eluting Stent with Biodegradable Polymer Ultimaster™ in Unselected Korean Population: A Multicenter, Prospective, Observational Study From Korean Multicenter Ultimaster Registry.

BACKGROUND AND OBJECTIVES: Ultimaster™, a third-generation sirolimus-eluting stent using biodegradable polymer, has been introduced to overcome long term adverse vascular events, such as restenosis or stent thrombosis. In the present study, we aimed to evaluate the 12-month clinical outcomes of Ultimaster™ stents in Korean patients with coronary artery disease. METHODS: This study is a multicenter, prospective, observational registry across 12 hospitals. To reflect real-world clinical evidence, non-selective subtypes of patients and lesions were included in this study. The study end point was target lesion failure (TLF) (the composite of cardiac death, target vessel myocardial infarction [MI], and target lesion revascularization [TLR]) at 12-month clinical follow up. RESULTS: A total of 576 patients were enrolled between November 2016 and May 2021. Most of the patients were male (76.5%), with a mean age of 66.0±11.2 years. Among the included patients, 40.1% had diabetes mellitus (DM) and 67.9% had acute coronary syndrome (ACS). At 12 months, the incidence of TLF was 4.1%. The incidence of cardiac death was 1.5%, MI was 1.0%, TLR was 2.7%, and stent thrombosis was 0.6%. In subgroup analysis based on the presence of ACS, DM, hypertension, dyslipidemia, or bifurcation, there were no major differences in the incidence of the primary endpoint. CONCLUSIONS: The present registry shows that Ultimaster™ stent is safe and effective for routine real-world clinical practice in non-selective Korean patients, having a low rate of adverse events at least up to 12 months.

Quantitative Topic Analysis of Materials Science Literature Using Natural Language Processing.

Materials science research has garnered extensive attention from industry, society, policy, and academia. However, understanding the research landscape and extracting strategic insights are challenging due to the increasing diversity and volume of publications. This study proposes a natural language processing-based protocol for extracting text-encoded topics from a large volume of scientific literature, uncovering research interests of scientific communities, as well as convergence trends. We report a topic map, representing the materials science research landscape with text-mined 257 topics regarding biocompatible materials, structural materials, electrochemistry, or photonics. We analyze the topic map in terms of national research interests in materials science, revealing competitive positions and strategies of active nations. For example, it is found that the increasing trend of research interest in machine learning topic was captured in the United States earlier than other nations. Similarly, our journal-level analyses serve as reference information for journal recommendations and trend guidance, showing that the main topics and research interests of materials science journals slightly changed over time. Moreover, we build the topic association network which can highlight the status and future potential of interdisciplinary research, revealing research fields with high centrality in the network such as machine learning-enabled composite modeling, energy policy, or wearable electronics. This study offers insightful results on current and near-future materials science research landscapes, facilitating the understanding of stakeholders, amidst the fast-evolving and diverse knowledge of materials science.

Comparison of the International Normalized Ratio Between a Point-of-Care Test and a Conventional Laboratory Test: the Latter Performs Better in Assessing Warfarin-induced Changes in Coagulation Factors.

Background: Point-of-care testing (POCT) coagulometers are increasingly used for monitoring warfarin therapy. However, in high international normalized ratio (INR) ranges, significant discrepancy in the INR between POCT and conventional laboratory tests occurs. We compared the INR of POCT (CoaguChek XS Plus; Roche Diagnostics, Mannheim, Germany) with that of a conventional laboratory test (ACL TOP 750; Instrumentation Laboratory SpA, Milan, Italy) and explored possible reasons for discrepancy. Methods: Paired POCT and conventional laboratory test INRs were analyzed in 400 samples from 126 patients undergoing warfarin therapy after cardiac surgery. Coagulation factor and thrombin generation tests were compared using the Mann-Whitney U test. Correlations between coagulation factors and INRs were determined using Pearson correlation coefficients. Results: The mean difference in the INR between the tests increased at high INR ranges. Endogenous thrombin potential levels were decreased at INR <2.0 for CoaguChek XS Plus and 2.0< INR <3.0 for ACL TOP 750 compared with those at INR <2.0 for both tests, indicating a better performance of ACL TOP 750 in assessing thrombin changes. The correlation coefficients of coagulation factors were stronger for ACL TOP 750 INR than for CoaguChek XS Plus INR. Vitamin K-dependent coagulation factors were found to contribute to the INR discrepancy. Conclusions: Decreases in vitamin K-dependent coagulation and anticoagulation factors can explain the significant discrepancy between the two tests in high INR ranges. Since conventional laboratory test INR values are more reliable than POCT INR values, a confirmatory conventional laboratory test is required for high INR ranges.

Optimized self-microemulsifying drug delivery system improves the oral bioavailability and brain delivery of coenzyme Q10.

Our study aimed to develop a self-microemulsifying drug delivery system for the poorly aqueous-soluble drug Coenzyme Q10, to improve the dissolution and the oral bioavailability. Excipients were selected based on their Coenzyme Q10 solubility, and their concentrations were set for the optimization of the microemulsion by using a D-optimal mixture design to achieve a minimum droplet size and a maximum solubility of Coenzyme Q10 within 15 min. The optimized formulation was composed of an oil (omega-3; 38.55%), a co-surfactant (Lauroglycol® 90; 31.42%), and a surfactant (Gelucire® 44/14; 30%) and exhibited a mean droplet size of 237.6 ± 5.8 nm and a drug solubilization (at 15 min) of 16 ± 2.48%. The drug dissolution of the optimized formulation conducted over 8 h in phosphate buffer medium (pH 6.8) was significantly higher when compared to that of the Coenzyme Q10 suspension. A pharmacokinetic study in rats revealed a 4.5-fold and a 4.1-fold increase in the area under curve and the peak plasma concentration values generated by the optimized formulation respectively, as compared to the Coenzyme Q10 suspension. A Coenzyme Q10 brain distribution study revealed a higher Coenzyme Q10 distribution in the brains of rats treated with the optimized formulation than the Coenzyme Q10 suspension. Coenzyme Q10-loaded self microemulsifying drug delivery system was successfully formulated and optimized by a response surface methodology based on a D-optimal mixture design and could be used as a delivery vehicle for the enhancement of the oral bioavailability and brain distribution of poorly soluble drugs such as Coenzyme Q10.

Effectiveness and safety of non-vitamin K direct oral anticoagulants in atrial fibrillation patients with bioprosthetic valve.

BACKGROUND: Non-vitamin K direct oral anticoagulant (DOAC) is effective for prevention of embolic events in nonvalvular atrial fibrillation (AF) patients. However, the effectiveness and safety of DOAC in AF patients who have bioprosthetic heart valve (BPHV) is largely unknown. METHODS: We retrospectively identified patients with AF and BPHV, using the diagnostic code and medical device and surgery information from the Korean National Health Insurance Service database, between 2013 and 2018. A 1:2 propensity score-matched cohort (n = 724 taking warfarin; n = 362 taking DOAC) was constructed and analyzed for the primary clinical outcome, a composite of ischemic stroke and systemic embolism. Important secondary outcomes included major bleeding, all-cause death, and the net clinical outcome, defined as a composite of all embolic events, major bleeding, and death. RESULTS: The mean age was 78.9±6.8 years old, and 45% (n = 489) were male. The mean CHA2DS2-VASc score was 4.7±1.4. DOAC was non-inferior to warfarin for preventing ischemic stroke and systemic embolism (hazard ratio [HR] 1.14, 95% confidence interval [CI] 0.56-2.34), major bleeding (HR 0.80, 95% CI 0.32-2.03) and all-cause death (HR 1.09, 95% CI 0.73-1.63). As for the net clinical outcome, DOAC was also similar to warfarin (HR 1.06, 95% CI 0.76-1.47). These outcomes were not different in various subgroups analyzed. CONCLUSION: In this nationwide Korean AF population with a BPHV, DOAC was at least as effective and safe as warfarin for the prevention of systemic embolic events. These results suggest that DOAC may be an excellent alternative to warfarin in AF patients with BPHV.

Real-World Three-Year Clinical Outcomes of Biolimus-Eluting Stents versus Other Contemporary Drug-Eluting Stents in Patients with Acute Myocardial Infarction Patients: Data from the Korea Acute Myocardial Infarction Registry (KAMIR).

INTRODUCTION: Biolimus-eluting stents (BES) are known to be superior to bare-metal stents. This study aims to evaluate the safety and efficacy of BES compared to other drug-eluting stents (DES) based on big data from the Korea Acute Myocardial Infarction Registry (KAMIR). METHODS: The study analyzed a total of 9,759 acute myocardial infarction (AMI) patients who underwent percutaneous coronary intervention (PCI) with DES. Total death, cardiac death, recurrent MI, revascularization, stent thrombosis, target lesion failure (TLF, composite of cardiac death, recurrent myocardial infarction (MI), and target lesion revascularization), and major adverse cardiac events (MACE, composite of total death, recurrent MI, and revascularization) were analyzed in patients with AMI up to three years. Study populations were divided into BES (n = 2,020), everolimus-eluting stents (EES, n = 5,293), and zotarolimus-eluting stents (ZES, n = 2,446) groups. RESULTS: To adjust baseline potential confounders, an inverse probability weighting (IPTW) analysis was performed. After IPTW, at three years, total death (7.2%, 8.6%, and 9.5%, P < 0.001), cardiac death (4.1%, 5.3%, and 6.6%, P < 0.001), recurrent MI (1.6%, 2.6%, and 3.2%, P < 0.001), TLF (6.5%, 8.1%, and 9.1%, P < 0.001), and MACE (15.8%, 17.5%, and 18.2%, P < 0.001) were lowest in the BES group compared with the other DES groups in AMI patients. During the 3-year clinical follow-up, the BES group showed better outcomes of MACE (hazard ratio (HR), 0.773; 95% confidence interval (CI), 0.676-0.884; P < 0.001), TLF (HR, 0.659; 95% CI, 0.538-0.808; P < 0.001), total death (HR, 0.687; 95% CI, 0.566-0.835; P < 0.001), and cardiac death (HR,0.593; 95% CI, 0.462-0.541; P < 0.001) than the EES groups. CONCLUSIONS: In this study, BES was superior to EES or ZES in reducing total death, cardiac death, TLF, and MACE in AMI patients.

Early Differentiation of Stress Cardiomyopathy from Acute Anterior Wall Myocardial Using Changing Cardiac Enzyme Patterns.

BACKGROUND: Most patients with acute anterior wall ST elevation myocardial infarction (STEMI) or stress cardiomyopathy (SCMP) show elevations in cardiac enzymes that peak within 24 hours. The changing pattern of cardiac enzymes can be an early clue to the differentiation of anterior STEMI and SCMP. METHODS: This study was a retrospective analysis (matching cases and respective control subjects) performed at a single center. We compared 27 patients with SCMP and 30 patients with anterior STEMI. We used laboratory data included cardiac marker, such as the initial creatine kinase MB (CK-MB) fraction and troponin T (Tn-T), at admission and peak CK-MB and Tn-T at follow up. RESULTS: The mean age was 69.3 ± 14.1 years, and 38.6% of patients were female. The SCMP patients were older, more often female, and had lower left ventricular ejection fractions than the anterior STEMI patients. The initial CK-MB was higher in the anterior STEMI group than in the SCMP group. In contrast, the initial Tn-T level was not significantly different between the 2 groups. Peak CK-MB and Tn-T levels and change from initial levels were significantly greater in the anterior STEMI group than they were in the SCMP group. SCMP could be differentiated from anterior STEMI based on peak CK-MB > 46.65 ng/mL or Tn-T > 1.56 ng/mL. CONCLUSIONS: Follow-up changes in cardiac enzymes can be an effective early tool for differentiating SCMP from anterior STEMI.

Suture reduction of the borderline ascending aortic dilatation during aortic valve replacement.

BACKGROUND: This study was conducted to evaluate the efficacy of simple suture reduction of the ascending aorta (SRA) performed with aortic valve replacement (AVR) in patients with borderline ascending aortic dilatation (45-50 mm). METHODS: Ninety-eight patients (ascending aortic diameter 47.7±3.4 mm) who underwent concomitant SRA with AVR were enrolled. Median follow-up duration was 83 (IQR 27-173) months. Computed tomographic angiography (CTA) follow-up was performed at 71 (47-149) months after surgery (N.=69). At least two CTA scans were performed in 34 patients (interval = 63 [46, 156] months). Early and long-term outcomes were evaluated, and dilatation rate (mm/year) of the repaired aorta was analyzed. Major adverse aortic events (MAEs) were defined as death related to aortic events, including sudden death, aortic rupture or dissection, aortic reoperation and recurrent aortic aneurysm (>45 mm). RESULTS: Early mortality rate was 2.0%. No patients had postoperative complications associated with SRA. A recurrent aortic aneurysm (>45 mm) was found in nine patients, but none of the patients had an ascending aorta diameter >50 mm. A multivariable analysis demonstrated that neither preoperative diameter of the ascending aorta nor bicuspid valve was associated with dilatation of the repaired aorta. Co-existing coronary artery disease was associated with both recurrent aneurysm and increased dilatation rate after SRA. There were two cases of sudden death and no one suffered from aortic dissection, rupture or aortic reoperation. Ten- and 20-year freedom rates from MAE were 90.3% and 79.3%, respectively. CONCLUSIONS: Concomitant SRA might be a safe and effective surgical alternative to ascending aorta replacement in AVR patients with borderline ascending aortic dilatation regardless of aortic valve pathology.

Negative differential transconductance device with a stepped gate dielectric for multi-valued logic circuits.

Multi-valued logic (MVL) technology is a promising approach for improving the data-handling capabilities and decreasing the power consumption of integrated circuits. This is especially attractive as conventional complementary metal-oxide-semiconductor technology is approaching its scaling and power density limits. Here, an ambipolar WSe2 field-effect transistor with two or more negative-differential-transconductance (NDT) regions in its transfer characteristic (NDTFET) is proposed for MVL applications of various radices. The operation and charge carrier transport mechanism of the NDTFET are studied first by Kelvin probe force microscopy, electrical, and capacitance-voltage measurements. Next, strategies for increasing the number of NDT regions and engineering the NDTFET transfer characteristic are discussed. Finally, the extensibility and tunability of our concept are demonstrated by adapting NDTFETs as core devices for ternary, quaternary, and quinary MVL inverters through simulations, where only WSe2 is employed as a channel material for all devices comprising the inverters. The MVL inverter operation principle and the mechanism of the multiple logic state formation are analyzed in detail. The proposed concept is practically verified by the fabrication of a ternary inverter.

Nonstructural NS5A Protein Regulates LIM and SH3 Domain Protein 1 to Promote Hepatitis C Virus Propagation.

Hepatitis C virus (HCV) propagation is highly dependent on cellular proteins. To identify the host factors involved in HCV propagation, we previously performed protein microarray assays and identified the LIM and SH3 domain protein 1 (LASP-1) as an HCV NS5A-interacting partner. LASP-1 plays an important role in the regulation of cell proliferation, migration, and protein-protein interactions. Alteration of LASP-1 expression has been implicated in hepatocellular carcinoma. However, the functional involvement of LASP1 in HCV propagation and HCV-induced pathogenesis has not been elucidated. Here, we first verified the protein interaction of NS5A and LASP-1 by both in vitro pulldown and coimmunoprecipitation assays. We further showed that NS5A and LASP-1 were colocalized in the cytoplasm of HCV infected cells. NS5A interacted with LASP-1 through the proline motif in domain I of NS5A and the tryptophan residue in the SH3 domain of LASP-1. Knockdown of LASP-1 increased HCV replication in both HCV-infected cells and HCV subgenomic replicon cells. LASP-1 negatively regulated viral propagation and thereby overexpression of LASP-1 decreased HCV replication. Moreover, HCV propagation was decreased by wild-type LASP-1 but not by an NS5A binding-defective mutant of LASP-1. We further demonstrated that LASP-1 was involved in the replication stage of the HCV life cycle. Importantly, LASP-1 expression levels were increased in persistently infected cells with HCV. These data suggest that HCV modulates LASP-1 via NS5A in order to regulate virion levels and maintain a persistent infection.

Modified basic and specific (BASP) classification for pattern hair loss.

BACKGROUND: In 2007, Lee et al. introduced a basic and specific (BASP) classification for pattern hair loss that was comprehensive and applicable regardless of race or gender. However, this BASP classification has several limitations. Frontal type hair loss classification is relatively crude, and a specific hair loss pattern cannot be ascertained when hair loss is associated with the temporal and occipital areas. METHODS: In our modified BASP classification, frontal type classification was subdivided into five instead of three grades. Basic type classification remained the same as in the previous method. In addition, information regarding the involvement of the temporal or occipital scalp was recorded. Accuracy and ease of use were evaluated and compared with the existing BASP classification in 138 patients with pattern hair loss. RESULTS: Temporal or occipital involvement was observed in 14 patients, accounting for 11.1% of subjects. Final type accuracy was 82.5% in the existing BASP classification and 71.4% in the modified classification. Ease of use for two practitioners was 70.2 and 72.1% for the existing BASP classification, and 48.9 and 52.2% for the modified method. CONCLUSION: We expect that the modified BASP classification will overcome the limitations of the existing BASP classification. We believe this modified classification will be a valuable tool for pattern hair loss classification because of its classification of previously unclassified types.

Optimization of Super-Hydrophobic Property by Two-Step Surface Modification.

The super-hydrophobic surface can be used in anti-pollution, self-cleaning, and anti-corrosive properties. Two-step surface treatment process on Al-coated glass was conducted by surface etching using potassium hydroxide (KOH) and surface coating using lauric acid for super-hydrophobic surface. The KOH-etched Al surface (1st etching) was changed to a hydrophilic property with a water contact angle (WCA) of 68° to 48°. On the other hand, the WCA of the etched Al surface was changed to about 153° with super-hydrophobic property when the lauric acid coating (2nd coating) was applied on the KOH-etched Al surface for 30 minutes. We found that the hydrophobicity of Al surface was related to the roughness by surface modification as well as the Al film thickness by sputtering method.

Super-Hydrophobic Properties of Aluminum Surfaces Synthesized by a Two-Step Chemical Etching Process.

In this study, super-hydrophobic coatings on Al surfaces were prepared by a two-step chemical etching process using potassium hydroxide and lauric acid as the etching solution and coating solution, respectively. The Al surface was roughened by immersion in potassium hydroxide, and an ethanolic solution of lauric acid was then coated onto the rough Al surface to lower the surface energy. The wettability and surface morphologies of the treated Al surfaces were characterized using contact angle measurement and scanning electron microscopy, respectively. Microstructures were formed on the treated Al surfaces, which increased the contact angle of the surface (>150°). The contact angle hysteresis was measured between 2.7° and 3° on average, indicating that the surface energy of the Al substrate was low, and the lauric acid was uniformly coated on the substrate. This super-hydrophobic coating showed excellent self-cleaning and corrosion-resistant behavior. The coated samples floated on the water surface and demonstrated excellent water repellent properties. In addition, the coatings were mechanically stable and had an excellent regeneration ability, as verified experimentally. The lauric acid used to lower the surface energy is considered more environment-friendly and more durable than the widely used polytetrafluoroethylene (PTFE).

Preparation and Characterization of the Sputtered TiAlN Coatings Using a Ti-Al Alloy Metal Target.

Titanium aluminium nitride (TiAlN) ternary coatings were deposited on glass substrates by means of reactive magnetron sputtering technique, using a Ti-Al alloy metal target (Ti0.5Al0.5). The depositions were performed at various N2 and Ar flux ratios of N2/(Ar + N2) ═ 33, 50, 67, 83%. The structure, morphology, chemical composition and mechanical properties were investigated by X-ray diffraction (XRD), field emission scanning electron microscope (FE-SEM), energy dispersive X-ray spectroscopy (EDS), and nano indenter (MTS System), respectively. The orientation of coatings depends on the flux ratios of N2/(Ar + N2) and substrate temperature. The coatings deposited with N2/(Ar + N2) ratios of 33, 50 at.% consists of pyramid-like column grains separated by porous and voids, which can be attributed to cubic-TiN (220) preferred orientation. The coatings deposited with N2/(Ar + N2) greater than 67% exhibits the phase of hexagonal-AlN and cubic-TiN. The surface of coatings becomes more compact and smoother with the N2/(Ar + N2) ratios increase. The coatings deposited with N2/(Ar+N2) ratio of 83% shows the largest hardness of 21.5 GPa, which is attributed to the preferred (200) orientation. However, this hardness increases significantly with increasing substrate temperature. The coatings deposited at more than 100 °C exhibited the (111) and/or (200) orientation. The amounts of grains grown along the (111) and (200) orientations play a significant role on the mechanical performance of TiAlN coatings. Four independent mechanisms, such as TiAlN stoichiometry and lattice parameter, the (111) preferred growth orientation, and the density increases (elimination of void), were found to contribute to the enhancement of TiAlN mechanical performance.

Complex formulations, simple techniques: Can 3D printing technology be the Midas touch in pharmaceutical industry?

3D printing is a method of rapid prototyping and manufacturing in which materials are deposited onto one another in layers to produce a three-dimensional object. Although 3D printing was developed in the 1980s and the technology has found widespread industrial applications for production from automotive parts to machine tools, its application in pharmaceutical area is still limited. However, the potential of 3D printing in the pharmaceutical industry is now being recognized. The ability of 3D printing to produce medications to exact specifications tailored to the needs of individual patients has indicated the possibility of developing personalized medicines. The technology allows dosage forms to be precisely printed in various shapes, sizes and textures that are difficult to produce using traditional techniques. However, there are various challenges associated with the proper application of 3D printing in the pharmaceutical sector which should be overcome to exploit the scope of this technology. In this review, an overview is provided on the various 3D printing technologies used in fabrication of complex dosage forms along with their feasibility and limitations.

Artificial optic-neural synapse for colored and color-mixed pattern recognition.

The priority of synaptic device researches has been given to prove the device potential for the emulation of synaptic dynamics and not to functionalize further synaptic devices for more complex learning. Here, we demonstrate an optic-neural synaptic device by implementing synaptic and optical-sensing functions together on h-BN/WSe2 heterostructure. This device mimics the colored and color-mixed pattern recognition capabilities of the human vision system when arranged in an optic-neural network. Our synaptic device demonstrates a close to linear weight update trajectory while providing a large number of stable conduction states with less than 1% variation per state. The device operates with low voltage spikes of 0.3 V and consumes only 66 fJ per spike. This consequently facilitates the demonstration of accurate and energy efficient colored and color-mixed pattern recognition. The work will be an important step toward neural networks that comprise neural sensing and training functions for more complex pattern recognition.

Development and Evaluation of a Water Soluble Fluorometholone Eye Drop Formulation Employing Polymeric Micelle.

Low aqueous solubility of drug causes difficulties in preparation and inconvenience of administration. Polymeric micelles of fluorometholone (FML) using solid dispersion technique were prepared to develop an eye drop formulation with enhanced water solubility. Solid dispersions of FML were prepared at various FML:Soluplus® w/w ratios using solvent evaporation method. A physical mixture was also prepared. Physicochemical characterization was performed with various methods. Ex vivo porcine corneal permeation of polymeric micelle, physical mixture, and commercial product were compared. FML solid dispersion (1:15) showed the highest solubility, which was c.a. 169.6- and 15.3-fold higher than that of pure FML and physical mixture. Characterization showed that the crystalline form of FML changed to amorphous state and polymeric micelles were formed in round micelle. Flucon®, a commercial product of FML, showed significantly large particle size and high poly dispersity index. In contrast, FML polymeric micelle showed submicron size with uniform size distribution. Ex vivo porcine corneal permeation study showed that permeation by polymeric micelles was significantly higher than that by the commercial product and physical mixture. In addition, confocal laser scanning microscopic analysis supported the enhanced porcine corneal tissue permeation property of polymeric micelle. In conclusion, polymeric micelle prepared with solid dispersion using Soluplus® can be a potential nanomedicine for ocular delivery of poorly water-soluble FML.

Hepatitis C Virus Modulates Solute carrier family 3 member 2 for Viral Propagation.

Hepatitis C virus (HCV) exploits an extensive network of host proteins to maintain chronic infection. Using RNA-Seq technology, we identified 30 host genes that were differentially expressed in cell culture grown HCV (HCVcc)-infected cells. Of these candidate genes, we selected solute carrier family 3 member 2 (SLC3A2) for further investigation. SLC3A2, also known as CD98hc, is a member of the solute carrier family and encodes a subunit of heterodimeric amino acid transporter. SLC3A2 and LAT1 constitute a heterodimeric transmembrane protein complex that catalyzes amino acid transport. In this study, we showed that HCV upregulated both mRNA and protein expression levels of SLC3A2 and this upregulation occurred through NS3/4A-mediated oxidative stress. HCV also elevated SLC3A2/LAT1 complex level and thus mammalian target of rapamycin complex 1 (mTORC1) signaling was activated. We further showed that L-leucine transport level was significantly increased in Jc1-infected cells as compared with mock-infected cells. Using RNA interference technology, we demonstrated that SLC3A2 was specifically required for the entry step but not for other stages of the HCV life cycle. These data suggest that SLC3A2 plays an important role in regulating HCV entry. Collectively, HCV exploits SLC3A2 for viral propagation and upregulation of SLC3A2 may contribute to HCV-mediated pathogenesis.