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1.
Sensors (Basel) ; 21(22)2021 Nov 17.
Artículo en Inglés | MEDLINE | ID: mdl-34833698

RESUMEN

Although numerous road segmentation studies have utilized vision data, obtaining robust classification is still challenging due to vision sensor noise and target object deformation. Long-distance images are still problematic because of blur and low resolution, and these features make distinguishing roads from objects difficult. This study utilizes light detection and ranging (LiDAR), which generates information that camera images lack, such as distance, height, and intensity, as a reliable supplement to address this problem. In contrast to conventional approaches, additional domain transformation to a bird's eye view space is executed to obtain long-range data with resolutions comparable to those of short-range data. This study proposes a convolutional neural network architecture that processes data transformed to a bird's eye view plane. The network's pathways are split into two parts to resolve calibration errors in the transformed image and point cloud. The network, which has modules that operate sequentially at various scaled dilated convolution rates, is designed to quickly and accurately handle a wide range of data. Comprehensive empirical studies using the Karlsruhe Institute of Technology and Toyota Technological Institute's (KITTI's) road detection benchmarks demonstrate that this study's approach takes advantage of camera and LiDAR information, achieving robust road detection with short runtimes. Our result ranks 22nd in the KITTI's leaderboard and shows real-time performance.


Asunto(s)
Redes Neurales de la Computación
2.
Biosens Bioelectron ; 179: 113065, 2021 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-33578116

RESUMEN

Recombinase polymerase amplification (RPA) is considered one of the best amplification methods for realizing a miniaturized diagnostic instrument; however, it is notably challenging to obtain low detection limits in solid-phase RPA. To overcome these difficulties, we combined solid-phase RPA with electrochemical detection and used a new concentration combination of three primers (surface-bound forward primer, solution reverse primer, and an extremely low concentration of solution forward primer). When solid-phase RPA was performed on an indium tin oxide (ITO) electrode modified with a surface-bound forward primer in a solution containing a biotin-terminated solution reverse primer, an extremely low concentration of a solution forward primer, and a template DNA or genomic DNA for a target gene of hepatitis B virus (HBV), amplification occurred mainly in solution until all the solution forward primers were consumed. Subsequently, DNA amplicons produced in solution participated in solid-phase amplification involving surface-bound forward primer and solution reverse primer. Afterward, neutravidin-conjugated DT-diaphorase (DT-D) was attached to a biotin-terminated DNA amplicon on the ITO electrode. Finally, chronocoulometric charges were measured using electrochemical-enzymatic redox cycling involving the ITO electrode, 1,4-naphthoquinone, DT-D, and reduced ß-nicotinamide adenine dinucleotide. The detection limit for HBV was measured using microfabricated electrodes and was found to be approximately 0.1 fM. This proposed method demonstrated better amplification efficiency for HBV genomic DNA than solid-phase RPA without using additional solution primer and asymmetric solid-phase RPA.


Asunto(s)
Técnicas Biosensibles , Hepatitis B , ADN Viral/genética , Hepatitis B/diagnóstico , Humanos , Técnicas de Amplificación de Ácido Nucleico , Recombinasas , Sensibilidad y Especificidad
3.
Adv Mater ; 32(33): e2002902, 2020 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-32579276

RESUMEN

Tubulin-based nanotubes (TNTs) to deliver microtubule-targeting agents (MTAs) for clinical oncology are reported. Three MTAs, docetaxel (DTX), laulimalide (LMD), and monomethyl auristatin E (MMAE), which attach to different binding sites in a tubulin, are loaded onto TNTs and cause structural changes in them, including shape anisotropy and tubulin layering. This drug-driven carrier transformation leads to changes in the drug-loading efficiency and stability characteristics of the carrier. TNTs coloaded with DTX and LMD efficiently deliver dual drug cargoes to cellular tubulins by the endolysosomal pathway, and results in synergistic anticancer and antiangiogenic action of the drugs in vitro. In in vivo tests, TNTs loaded with a microtubule-destabilizing agent MMAE suppress the growth of tumors with much higher efficacy than free MMAE did. This work suggests a new concept of using a drug's target protein as a carrier. The findings demonstrate that the TNTs developed here can be used universally as a delivery platform for many MTAs.


Asunto(s)
Portadores de Fármacos/química , Microtúbulos/metabolismo , Terapia Molecular Dirigida , Nanotubos/química , Tubulina (Proteína)/química , Animales , Antineoplásicos/química , Antineoplásicos/farmacología , Línea Celular Tumoral , Liberación de Fármacos , Humanos , Ratones , Ensayos Antitumor por Modelo de Xenoinjerto
4.
Angew Chem Int Ed Engl ; 59(34): 14628-14638, 2020 08 17.
Artículo en Inglés | MEDLINE | ID: mdl-32430981

RESUMEN

We describe a small lipid nanoparticle (SLNP)-based nanovaccine platform and a new combination treatment regimen. Tumor antigen-displaying, CpG adjuvant-embedded SLNPs (OVAPEP -SLNP@CpG) were prepared from biocompatible phospholipids and a cationic cholesterol derivative. The resulting nanovaccine showed highly potent antitumor efficacy in both prophylactic and therapeutic E.G7 tumor models. However, this vaccine induced T cell exhaustion by elevating PD-L1 expression, leading to tumor recurrence. Thus, the nanovaccine was combined with simultaneous anti-PD-1 antibody treatment, but the therapeutic efficacy of this regimen was comparable to that of the nanovaccine alone. Finally, mice that showed a good therapeutic response after the first cycle of immunization with the nanovaccine underwent a second cycle together with anti-PD-1 therapy, resulting in suppression of tumor relapse. This suggests that the antitumor efficacy of combinations of nanovaccines with immune checkpoint blockade therapy is dependent on treatment sequence and the timing of each modality.


Asunto(s)
Vacunas contra el Cáncer/administración & dosificación , Proliferación Celular , Inhibidores de Puntos de Control Inmunológico/administración & dosificación , Nanotecnología , Neoplasias/terapia , Animales , Ensayo de Inmunoadsorción Enzimática , Humanos , Ratones , Neoplasias/patología
5.
J Drug Target ; 28(7-8): 780-788, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32116049

RESUMEN

Despite the wide utility of gold nanorods (GNRs) in biomedical fields, only a few methods for modifying or coating the surface of GNRs suitable for biomedical applications are available. In this study, we report a new facile method that enables formation of an ultra-thin (nanometre-thickness) siloxane layer on GNRs with anti-biofouling properties and ligand functionalisation ability. A triblock random copolymer, poly(TMSMA-r-PEGMA-r-NAS), was used to coat GNRs. An ultrathin polymeric shell was formed surrounding GNRs through acid-catalysed crosslinking of silicates of TMSMA. The polymer-coated GNRs (p-GNRs) exhibited high colloidal stability in biological solutions of high ionic strength and long-term stability superior to that of PEG2k-S-GNRs. The functionalities of NAS were demonstrated using two methods for conjugating targeting ligands and loading doxorubicin via electrostatic interactions. The ligand-specific cancer-targeting ability and combinatorial chemo-photothermal anticancer effects were validated in vitro and in vivo, suggesting their potential utility in various fields.


Asunto(s)
Química Farmacéutica/métodos , Sistemas de Liberación de Medicamentos/métodos , Oro/química , Nanotubos/química , Siloxanos/química , Animales , Línea Celular Tumoral , Doxorrubicina/administración & dosificación , Doxorrubicina/farmacocinética , Humanos , Ratones , Ratones Endogámicos BALB C , Polietilenglicoles/química , Polímeros
6.
Anal Chem ; 92(5): 3932-3939, 2020 03 03.
Artículo en Inglés | MEDLINE | ID: mdl-32083468

RESUMEN

Catalytic precipitation and subsequent electrochemical oxidation or reduction of a redox-active precipitate has been widely used in electrochemical biosensors. However, such biosensors often do not allow for low detection limits due to a low rate of precipitation, nonspecific precipitation, loose binding of the precipitate to the electrode surface, and insulating behavior of the precipitate within a normal potential window. Here, we report an ultrasensitive electrochemical immunosensor for parathyroid hormone (PTH) detection based on DT-diaphorase (DT-D)-catalyzed formation of an organic precipitate and electrochemical oxidation of the precipitate. In the present study we found that DT-D can be used as a catalytic label in precipitation-based affinity biosensors because DT-D catalyzes fast reduction of 3-(4,-5-dimethylthiazo-2-yl)-2,5-diphenyltetrazolium bromide (MTT) to MTT-formazan precipitate; the MTT reduction does not occur in the absence of DT-D; and a high electrochemical signal is obtained at low potentials during electrodissolution of MTT-formazan precipitate. The immunosensor is fabricated using a silane copolymer-modified ITO electrode surface that is suitable for both efficient and strong adsorption of MTT-formazan precipitate. When the enzymatic MTT-formazan precipitation and subsequent MTT-formazan electrodissolution is applied to a sandwich-type immunosensor, PTH can be detected over a wide range of concentrations with a very low detection limit (∼1 pg/mL) in artificial serum. The measured concentrations of PTH in clinical serum samples showed high similarity with those obtained using a commercial instrument.


Asunto(s)
Técnicas Biosensibles/métodos , Formazáns/química , NAD(P)H Deshidrogenasa (Quinona)/química , Hormona Paratiroidea/análisis , Sales de Tetrazolio/química , Catálisis , Técnicas Electroquímicas , Electrodos , Humanos , Oxidación-Reducción , Hormona Paratiroidea/sangre
7.
Angew Chem Int Ed Engl ; 58(7): 2005-2010, 2019 02 11.
Artículo en Inglés | MEDLINE | ID: mdl-30600870

RESUMEN

Peptide-based therapeutics have suffered from a short plasma half-life. On the other hand, antibodies suffer from poor penetration into solid tumors owing to their large size. Herein, we present a new molecular form, namely a hybrid complex between a hapten-labeled bispecific peptide and an anti-hapten antibody ("HyPEP-body"), that may be able to overcome the aforementioned limitation. The bispecific peptide containing a cotinine tag was synthesized by linking a peptide specific to fibronectin extra domain B (EDB) and a peptide able to bind and inhibit vascular endothelial growth factor (VEGF), yielding cot-biPEPEDB-VEGF . Simple mixing of cot-biPEPEDB-VEGF and anti-cotinine antibody (Abcot ) yielded the hybrid complex, HyPEPEDB-VEGF . HyPEPEDB-VEGF retained the characteristics of the included peptides, and showed improved pharmacokinetic behavior. Moreover, HyPEPEDB-VEGF showed tumor growth inhibition with excellent tumor accumulation and penetration. These findings suggest that the hybrid platform described here offers a solution for most peptide therapeutics that suffer from a short circulation half-life in blood.


Asunto(s)
Anticuerpos Biespecíficos/farmacología , Antineoplásicos/farmacología , Péptidos/farmacología , Animales , Anticuerpos Biespecíficos/química , Antineoplásicos/química , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Ensayos de Selección de Medicamentos Antitumorales , Humanos , Ratones , Neoplasias Experimentales/tratamiento farmacológico , Neoplasias Experimentales/metabolismo , Neoplasias Experimentales/patología , Células PC-3 , Péptidos/química , Factor A de Crecimiento Endotelial Vascular/antagonistas & inhibidores , Factor A de Crecimiento Endotelial Vascular/metabolismo
8.
J Am Chem Soc ; 140(7): 2409-2412, 2018 02 21.
Artículo en Inglés | MEDLINE | ID: mdl-29419287

RESUMEN

Direct electron transfer between a redox label and an electrode requires a short working distance (<1-2 nm), and in general an affinity biosensor based on direct electron transfer requires a finely smoothed Au electrode to support efficient target binding. Here we report that direct electron transfer over a longer working distance is possible between (i) an anionic π-conjugated polyelectrolyte (CPE) label having many redox-active sites and (ii) a readily prepared, thin polymeric monolayer-modified indium-tin oxide electrode. In addition, the long CPE label (∼18 nm for 10 kDa) can approach the electrode within the working distance after sandwich-type target-specific binding, and fast CPE-mediated oxidation of ammonia borane along the entire CPE backbone affords high signal amplification.


Asunto(s)
ADN/análisis , Polielectrolitos/química , Transporte de Electrón
9.
ACS Appl Mater Interfaces ; 9(23): 19736-19745, 2017 Jun 14.
Artículo en Inglés | MEDLINE | ID: mdl-28569502

RESUMEN

As reports of multidrug resistant pathogens have increased, patients with implanted medical catheters increasingly need alternative solutions to antibiotic treatments. As most catheter-related infections are directly associated with biofilm formation on the catheter surface, which, once formed, is difficult to eliminate, a promising approach to biofilm prevention involves inhibiting the initial adhesion of bacteria to the surface. In this study, we report an amphiphilic, antifouling polymer, poly(DMA-mPEGMA-AA) that can facilely coat the surfaces of commercially available catheter materials in water and prevent bacterial adhesion to and subsequent colonization of the surface, giving rise to an antibiofilm surface. The antifouling coating layer was formed simply by dipping a model substrate (polystyrene, PET, PDMS, or silicon-based urinary catheter) in water containing poly(DMA-mPEGMA-AA), followed by characterization by X-ray photoelectron spectroscopy (XPS). The antibacterial adhesion properties of the polymer-coated surface were assessed for Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli) growth under static (incubation in the presence of a bacterial suspension) and dynamic (bacteria suspended in a solution under flow) conditions. Regardless of the conditions, the polymer-coated surface displayed significantly reduced attachment of the bacteria (antiadhesion effect > ∼8-fold) compared to the bare noncoated substrates. Treatment of the implanted catheters with S. aureus in vivo further confirmed that the polymer-coated silicon urinary catheters could significantly reduce bacterial adhesion and biofilm formation in a bacterial infection animal model. Furthermore, the polymer-coated catheters did not induce hemolysis and were resistant to the adhesion of blood-circulating cells, indicative of high biocompatibility. Collectively, the present amphiphilic antifouling polymer is potentially useful as a coating platform that renders existing medical devices resistant to biofilm formation.


Asunto(s)
Polímeros/química , Animales , Adhesión Bacteriana , Biopelículas , Incrustaciones Biológicas , Catéteres , Materiales Biocompatibles Revestidos , Escherichia coli , Staphylococcus aureus , Agua
10.
Anal Chem ; 89(3): 2024-2031, 2017 02 07.
Artículo en Inglés | MEDLINE | ID: mdl-28208259

RESUMEN

Both high sensitivity and high specificity are crucial for detection of miRNAs that have emerged as important clinical biomarkers. Just Another Zinc finger proteins (JAZ, ZNF346) bind preferably (but nonsequence-specifically) to DNA-RNA hybrids over single-stranded RNAs, single-stranded DNAs, and double-stranded DNAs. We present an ultrasensitive and highly specific electrochemical method for miRNA-21 detection based on the selective binding of JAZ to the DNA-RNA hybrid formed between a DNA capture probe and a target miRNA-21. This enables us to use chemically stable DNA as a capture probe instead of RNA as well as to apply a standard sandwich-type assay format to miRNA detection. High signal amplification is obtained by (i) enzymatic amplification by alkaline phosphatase (ALP) coupled with (ii) electrochemical-chemical-chemical (ECC) redox cycling involving an ALP product (hydroquinone). Low nonspecific adsorption of ALP-conjugated JAZ is obtained using a polymeric self-assembled-monolayer-modified and casein-treated indium-tin oxide electrode. The detection method can discriminate between target miRNA-21 and nontarget nucleic acids (DNA-DNA hybrid, single-stranded DNA, miRNA-125b, miRNA-155, single-base mismatched miRNA, and three-base mismatched miRNA). The detection limits for miRNA-21 in buffer and 10-fold diluted serum are approximately 2 and 30 fM, respectively, indicating that the detection method is ultrasensitive. This detection method can be readily extended to multiplex detection of miRNAs with only one ALP-conjugated JAZ probe due to its nonsequence-specific binding character. We also believe that the method could offer a promising solution for point-of-care testing of miRNAs in body fluids.


Asunto(s)
Proteínas de Unión al ADN/metabolismo , ADN/metabolismo , Técnicas Electroquímicas/métodos , MicroARNs/análisis , Proteínas de Unión al ARN/metabolismo , ARN/metabolismo , Dedos de Zinc , Fosfatasa Alcalina/química , Técnicas Electroquímicas/normas , Electrodos , Humanos , Límite de Detección , Hibridación de Ácido Nucleico
11.
Angew Chem Int Ed Engl ; 55(36): 10676-80, 2016 08 26.
Artículo en Inglés | MEDLINE | ID: mdl-27485478

RESUMEN

Although stimuli-responsive materials hold potential for use as drug-delivery carriers for treating cancers, their clinical translation has been limited. Ideally, materials used for the purpose should be biocompatible and nontoxic, provide "on-demand" drug release in response to internal or external stimuli, allow large-scale manufacturing, and exhibit intrinsic anticancer efficacy. We present multistimuli-responsive nanoparticles formed from bilirubin, a potent endogenous antioxidant that possesses intrinsic anticancer and anti-inflammatory activity. Exposure of the bilirubin nanoparticles (BRNPs) to either reactive oxygen species (ROS) or external laser light causes rapid disruption of the BRNP nanostructure as a result of a switch in bilirubin solubility, thereby releasing encapsulated drugs. In a xenograft tumor model, BRNPs loaded with the anticancer drug doxorubicin (DOX@BRNPs), when combined with laser irradiation of 650 nm, significantly inhibited tumor growth. This study suggests that BRNPs may be used as a drug-delivery carrier as well as a companion medicine for effectively treating cancers.


Asunto(s)
Adenocarcinoma/tratamiento farmacológico , Antibióticos Antineoplásicos/administración & dosificación , Bilirrubina/química , Preparaciones de Acción Retardada/química , Doxorrubicina/administración & dosificación , Neoplasias Pulmonares/tratamiento farmacológico , Nanopartículas/química , Células A549 , Adenocarcinoma/patología , Adenocarcinoma del Pulmón , Animales , Antibióticos Antineoplásicos/farmacocinética , Antibióticos Antineoplásicos/uso terapéutico , Doxorrubicina/farmacocinética , Doxorrubicina/uso terapéutico , Humanos , Neoplasias Pulmonares/patología , Ratones
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