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BACKGROUND: This study investigated predictive factors for patients with peritoneal metastases of gastric cancer (PMGC) who underwent conversion cytoreductive surgery (C-CRS) and hyperthermic intraperitoneal intraoperative chemotherapy (HIPEC) after responding to induction chemotherapy (laparoscopic HIPEC [LHIPEC]) followed by concomitant systemic and intraperitoneal chemotherapy (bidirectional intraperitoneal and systemic chemotherapy [BIC]). METHODS: Diagnostic laparoscopy was performed for 62 patients with PMGC between January 2017 and December 2022. The patients underwent LHIPEC and BIC induction chemotherapy using intraperitoneal docetaxel (30 mg/m2) and cisplatin (30 mg/m2), and intravenous chemotherapy for three cycles. The predictive parameters for progression-free and overall survival were analyzed using Kaplan-Meier and Cox regression analyses. The optimal cutoff values for Ki-67 parameters were assessed using receiver operating characteristic curve analysis. RESULTS: The study retrospectively examined 36 (58 %) of 62 patients who responded to induction therapy and underwent C-CRS or HIPEC. A Ki-67 index lower than 10 (p = 0.000), lymph node involvement (LNI) less than 2 (p = 0.039), and an omental lesion size score lower than 0.5 cm (p = 0.002) were predictive of recurrence-free and overall survival in addition to completeness of cytoreduction and the peritoneal cancer index. Cox regression analysis showed that the independent factors associated with recurrence-free survival were decreased Ki-67 expression (≥10 % vs <10 %) (hazard ratio [HR] 4.7; 95 % confidence interval [CI] 1.6-5.210; p = 0.020) and LNI higher than 2 (HR 1.92; 95% CIS 0.923-4.0; p = 0.023). CONCLUSIONS: Lymph node involvement and decreased Ki-67 expression are independent predictive factors of recurrence-free survival for patients with PMGC after induction chemotherapy.
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Protocolos de Quimioterapia Combinada Antineoplásica , Procedimentos Cirúrgicos de Citorredução , Docetaxel , Quimioterapia Intraperitoneal Hipertérmica , Neoplasias Peritoneais , Neoplasias Gástricas , Humanos , Neoplasias Gástricas/patologia , Neoplasias Gástricas/terapia , Neoplasias Peritoneais/secundário , Neoplasias Peritoneais/terapia , Neoplasias Peritoneais/mortalidade , Feminino , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Taxa de Sobrevida , Prognóstico , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Seguimentos , Idoso , Docetaxel/administração & dosagem , Cisplatino/administração & dosagem , Adulto , Quimioterapia de Indução , Terapia Combinada , Recidiva Local de Neoplasia/patologia , Recidiva Local de Neoplasia/terapia , Antígeno Ki-67/metabolismo , Antígeno Ki-67/análise , LaparoscopiaRESUMO
Immunogenic cell death (ICD), an immune-priming form of cell death, has been shown to be induced by several different anti-cancer therapies. Despite being the first and one of the most successful antibody-drug conjugates (ADCs) approved for refractory HER2-positive breast cancer, little is known if response and resistance to trastuzumab emtansine (T-DM1) involves ICD modulation that can be leveraged to enhance T-DM1 response. Here, we report that T-DM1 induces spindle assembly checkpoint (SAC)-dependent ICD in sensitive cells by inducing eIF2α phosphorylation, surface exposure of calreticulin, ATP and HMGB1 release, and secretion of ICD-related cytokines, all of which are lost in resistance. Accordingly, an ICD-related gene signature correlates with clinical response to T-DM1-containing therapy. We found that transforming acidic coiled-coil containing 3 (TACC3) is overexpressed in T-DM1 resistant cells, and that T-DM1 responsive patients have reduced TACC3 protein while the non-responders exhibited increased TACC3 expression during T-DM1 treatment. Notably, genetic or pharmacological inhibition of TACC3 revives T-DM1-induced SAC activation and induction of ICD markers in vitro. Finally, TACC3 inhibition elicits ICD in vivo shown by vaccination assay, and it potentiates T-DM1 by inducing dendritic cell (DC) maturation and enhancing infiltration of cytotoxic T cells in the human HER2-overexpressing MMTV.f.huHER2#5 (Fo5) transgenic model. Together, our results show that ICD is a key mechanism of action of T-DM1 which is lost in resistance, and that targeting TACC3 restores T-DM1-mediated ICD and overcomes resistance.
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Through coaxial direct ink writing, we fabricated a core-shell mesh system for the controlled release of carbon dots (C-dots). In the core ink, we developed an ink formulation with tuned viscosity using hydroxypropyl cellulose and polyethylene glycol to host C-dots. Polycaprolactone was employed as the main shell material, in combination with sodium alginate, to control the degradation rate of the shell. We investigated the degradation profile of the 3D-printed meshes and tracked the weekly release of C-dots in an aqueous medium by spectrofluorometry. We tested the efficacy of the C-dot release on plants by placing the meshes in transparent soil with Triticum aestivum L. seeds. We observed the in vivo translocation of the C-dots in the plant using confocal microscopy. We measured the root elongation and shoot length to assess the effect of C-dots on plant growth. Our study revealed that the plants exposed to C-dots grew 2.5-fold faster than the control group, indicating that C-dots are promising nanofertilizers for aggrotech and non-toxic fluorescent biolabels for in vivo applications.
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Centrosome amplification (CA) is a hallmark of cancer that is strongly associated with highly aggressive disease and worse clinical outcome. Clustering extra centrosomes is a major coping mechanism required for faithful mitosis of cancer cells with CA that would otherwise undergo mitotic catastrophe and cell death. However, its underlying molecular mechanisms have not been fully described. Furthermore, little is known about the processes and players triggering aggressiveness of cells with CA beyond mitosis. Here, we identified Transforming Acidic Coiled-Coil Containing Protein 3 (TACC3) to be overexpressed in tumors with CA, and its high expression is associated with dramatically worse clinical outcome. We demonstrated, for the first time, that TACC3 forms distinct functional interactomes regulating different processes in mitosis and interphase to ensure proliferation and survival of cancer cells with CA. Mitotic TACC3 interacts with the Kinesin Family Member C1 (KIFC1) to cluster extra centrosomes for mitotic progression, and inhibition of this interaction leads to mitotic cell death via multipolar spindle formation. Interphase TACC3 interacts with the nucleosome remodeling and deacetylase (NuRD) complex (HDAC2 and MBD2) in nucleus to inhibit the expression of key tumor suppressors (e.g., p21, p16 and APAF1) driving G1/S progression, and its inhibition blocks these interactions and causes p53-independent G1 arrest and apoptosis. Notably, inducing CA by p53 loss/mutation increases the expression of TACC3 and KIFC1 via FOXM1 and renders cancer cells highly sensitive to TACC3 inhibition. Targeting TACC3 by guide RNAs or small molecule inhibitors strongly inhibits growth of organoids and breast cancer cell line- and patient-derived xenografts with CA by induction of multipolar spindles, mitotic and G1 arrest. Altogether, our results show that TACC3 is a multifunctional driver of highly aggressive breast tumors with CA and that targeting TACC3 is a promising approach to tackle this disease.
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Neoplasias da Mama , Fuso Acromático , Humanos , Feminino , Fuso Acromático/metabolismo , Proteínas Associadas aos Microtúbulos/metabolismo , Neoplasias da Mama/patologia , Proteína Supressora de Tumor p53/metabolismo , Centrossomo/metabolismo , Proteínas de Ciclo Celular/metabolismo , Linhagem Celular Tumoral , Proteínas de Ligação a DNA/metabolismoRESUMO
Structural color-a widespread phenomenon observed throughout nature is caused by light interference from ordered phases of matter. While state-of-the-art nanofabrication techniques can produce structural organization in small areas, cost-effective and scalable techniques are still lacking to generate tunable color at sub-micron length scales. In this work, structurally colored hydroxypropyl cellulose filaments are produced with a suppressed angular color response by 3D printing. The systematic study of the morphology of the filaments reveals the key stages in the induction of a two-degree hierarchical order through 3D printing. The first degree of order originated from the changing of the cholesteric pitch at a few hundred nm scale via chemical modification and tuning of the solid content of the lyotropic phase. Upon 3D printing, the secondary hierarchical order of periodic wrinkling is introduced through the Helfrich-Hurault deformation of the shear-aligned cholesteric phases. In single-layered filaments, four morphological zones with varying orders of wrinkles are identified. Detailed morphological characterization is carried out using SEM to shed light on the mechanism of the wrinkling behavior. Through this work, the possibility of modifying the wrinkling behavior is demonstrated and thus the angle dependence of the color response by changing the printing conditions.
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Chemoresistance is a major obstacle in triple negative breast cancer (TNBC), the most aggressive breast cancer subtype. Here we identify hypoxia-induced ECM re-modeler, lysyl oxidase (LOX) as a key inducer of chemoresistance by developing chemoresistant TNBC tumors in vivo and characterizing their transcriptomes by RNA-sequencing. Inhibiting LOX reduces collagen cross-linking and fibronectin assembly, increases drug penetration, and downregulates ITGA5/FN1 expression, resulting in inhibition of FAK/Src signaling, induction of apoptosis and re-sensitization to chemotherapy. Similarly, inhibiting FAK/Src results in chemosensitization. These effects are observed in 3D-cultured cell lines, tumor organoids, chemoresistant xenografts, syngeneic tumors and PDX models. Re-expressing the hypoxia-repressed miR-142-3p, which targets HIF1A, LOX and ITGA5, causes further suppression of the HIF-1α/LOX/ITGA5/FN1 axis. Notably, higher LOX, ITGA5, or FN1, or lower miR-142-3p levels are associated with shorter survival in chemotherapy-treated TNBC patients. These results provide strong pre-clinical rationale for developing and testing LOX inhibitors to overcome chemoresistance in TNBC patients.
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Antineoplásicos/farmacologia , Resistencia a Medicamentos Antineoplásicos , Proteína-Lisina 6-Oxidase/antagonistas & inibidores , Neoplasias de Mama Triplo Negativas/tratamento farmacológico , Neoplasias de Mama Triplo Negativas/enzimologia , Animais , Apoptose , Biomarcadores Tumorais/metabolismo , Linhagem Celular Tumoral , Colágeno/química , Regulação para Baixo , Matriz Extracelular/metabolismo , Feminino , Fibronectinas/metabolismo , Quinase 1 de Adesão Focal/metabolismo , Regulação Neoplásica da Expressão Gênica , Humanos , Hipóxia , Integrinas/metabolismo , Camundongos , Camundongos Nus , MicroRNAs/metabolismo , Transplante de Neoplasias , RNA-Seq , Transdução de SinaisRESUMO
TACC3, a transforming acidic coiled-coil (TACC) family member, is frequently upregulated in a broad spectrum of cancers, including breast cancer. It plays critical roles in protecting microtubule stability and centrosome integrity that is often dysregulated in cancers; therefore, making TACC3 a highly attractive therapeutic target. Here, we identified a new TACC3-targeting chemotype, BO-264, through the screening of in-house compound collection. Direct interaction between BO-264 and TACC3 was validated by using several biochemical methods, including drug affinity responsive target stability, cellular thermal shift assay, and isothermal titration calorimetry. BO-264 demonstrated superior antiproliferative activity to the two currently reported TACC3 inhibitors, especially in aggressive breast cancer subtypes, basal and HER2+, via spindle assembly checkpoint-dependent mitotic arrest, DNA damage, and apoptosis, while the cytotoxicity against normal breast cells was negligible. Furthermore, BO-264 significantly decreased centrosomal TACC3 during both mitosis and interphase. BO-264 displayed potent antiproliferative activity (â¼90% have less than 1 µmol/L GI50 value) in the NCI-60 cell line panel compromising of nine different cancer types. Noteworthy, BO-264 significantly inhibited the growth of cells harboring FGFR3-TACC3 fusion, an oncogenic driver in diverse malignancies. Importantly, its oral administration significantly impaired tumor growth in immunocompromised and immunocompetent breast and colon cancer mouse models, and increased survival without any major toxicity. Finally, TACC3 expression has been identified as strong independent prognostic factor in breast cancer and strongly prognostic in several different cancers. Overall, we identified a novel and highly potent TACC3 inhibitor as a novel potential anticancer agent, inducing spindle abnormalities and mitotic cell death.
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Antineoplásicos/farmacologia , Biomarcadores Tumorais/metabolismo , Neoplasias da Mama/tratamento farmacológico , Neoplasias do Colo/tratamento farmacológico , Regulação Neoplásica da Expressão Gênica , Proteínas Associadas aos Microtúbulos/antagonistas & inibidores , Mitose , Animais , Apoptose , Biomarcadores Tumorais/genética , Neoplasias da Mama/genética , Neoplasias da Mama/metabolismo , Neoplasias da Mama/patologia , Ciclo Celular , Movimento Celular , Proliferação de Células , Neoplasias do Colo/genética , Neoplasias do Colo/metabolismo , Neoplasias do Colo/patologia , Feminino , Ensaios de Triagem em Larga Escala , Humanos , Camundongos , Camundongos Nus , Proteínas Associadas aos Microtúbulos/genética , Proteínas Associadas aos Microtúbulos/metabolismo , Microtúbulos , Proteínas de Fusão Oncogênica/antagonistas & inibidores , Proteínas de Fusão Oncogênica/genética , Prognóstico , Receptor Tipo 3 de Fator de Crescimento de Fibroblastos/antagonistas & inibidores , Receptor Tipo 3 de Fator de Crescimento de Fibroblastos/genética , Fuso Acromático , Células Tumorais Cultivadas , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
BACKGROUND: There is a need for a peripheral nerve model on which surgeons-in-training can simulate the repair of nerve injuries at their own pace. Although practicing on animal models/cadavers is considered the "gold standard" of microsurgical training, the proposed model aims to provide a platform for improving the technical skills of surgical trainees prior to their practice on cadaver/animal models. In addition, this model has the potential to serve as a standardized test medium for assessing the skill sets of surgeons. METHODS: Several formulations of silicone were utilized for the design and fabrication of a model which realizes the hierarchical structure of peripheral nerves. The mechanical properties were characterized via the Universal Testing Machine; the damage caused by the needle on the entry sites was assessed through scanning electron microscopy (SEM). RESULTS: Mechanical properties of the formulations of silicone were tested to mimic human peripheral nerves. A formulation with 83.3â¯wt% silicone oil and 0.1â¯wt% cotton fiber was chosen to be used as nerve fascicles. Both 83.3â¯wt% silicone oil with cotton fiber and 66.6â¯wt% silicone oil without fiber provided a microsuturing response similar to that of epineurium at a wall thickness of 1â¯mm. SEM also confirmed that the entry of the needle did not introduce significant holes at the microsuturing sites. CONCLUSIONS: The proposed peripheral nerve model mimicked human tissues mechanically and cosmetically, and a simulation of the repair of a fifth-degree nerve injury was achieved.
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Microcirurgia/métodos , Modelos Anatômicos , Nervos Periféricos/cirurgia , Humanos , Microscopia Eletrônica de Varredura , Microcirurgia/educação , Traumatismos dos Nervos Periféricos/cirurgia , Nervos Periféricos/anatomia & histologia , Nervos Periféricos/ultraestrutura , SiliconesRESUMO
A silicone-based composite breast phantom is fabricated to be used as an education model in ultrasonography training. A matrix of silicone formulations is tracked to mimic the ultrasonography and tactile response of human breast tissue. The performance of two different additives: (i) silicone oil and (ii) vinyl-terminated poly (dimethylsiloxane) (PDMS) are monitored by a home-made acoustic setup. Through the use of 75â¯wt% vinyl-terminated PDMS in two-component silicone elastomer mixture, a sound velocity of 1.29⯱â¯0.09â¯×â¯103â¯m/s and an attenuation coefficient of 12.99⯱â¯0.08â¯dB/cm-values those match closely to the human breast tissue-are measured with 5â¯MHz probe. This model can also be used for needle biopsy as well as for self-exam trainings. Herein, we highlight the fabrication of a realistic, durable, accessible, and cost-effective training platform that contains skin layer, inner breast tissue, and tumor masses.
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Biópsia Guiada por Imagem , Imagens de Fantasmas , Silicones/química , Ultrassonografia de Intervenção , Ultrassonografia Mamária , Acústica , Biópsia por Agulha , Dimetilpolisiloxanos/química , Desenho de Equipamento , Análise de Falha de Equipamento , Humanos , Nylons/químicaRESUMO
Trastuzumab-refractory, HER2 (human epidermal growth factor receptor 2)-positive breast cancer is commonly treated with trastuzumab emtansine (T-DM1), an antibody-drug conjugate of trastuzumab and the microtubule-targeting agent, DM1. However, drug response reduces greatly over time due to acquisition of resistance whose molecular mechanisms are mostly unknown. Here, we uncovered a novel mechanism of resistance against T-DM1 by combining whole transcriptome sequencing (RNA-Seq), proteomics and a targeted small interfering RNA (siRNA) sensitization screen for molecular level analysis of acquired and de novo T-DM1-resistant models of HER2-overexpressing breast cancer. We identified Polo-like kinase 1 (PLK1), a mitotic kinase, as a resistance mediator whose genomic as well as pharmacological inhibition restored drug sensitivity. Both acquired and de novo resistant models exhibited synergistic growth inhibition upon combination of T-DM1 with a selective PLK1 inhibitor, volasertib, at a wide concentration range of the two drugs. Mechanistically, T-DM1 sensitization upon PLK1 inhibition with volasertib was initiated by a spindle assembly checkpoint (SAC)-dependent mitotic arrest, leading to caspase activation, followed by DNA damage through CDK1-dependent phosphorylation and inactivation of Bcl-2/xL. Furthermore, we showed that Ser70 phosphorylation of Bcl-2 directly regulates apoptosis by disrupting the binding to and sequestration of the pro-apoptotic protein Bim. Importantly, T-DM1 resistance signature or PLK1 expression correlated with cell cycle progression and DNA repair, and predicted a lower sensitivity to taxane/trastuzumab combination in HER2-positive breast cancer patients. Finally, volasertib in combination with T-DM1 greatly synergized in models of T-DM1 resistance in terms of growth inhibition both in three dimensional (3D) cell culture and in vivo. Altogether, our results provide promising pre-clinical evidence for potential testing of T-DM1/volasertib combination in T-DM1 refractory HER2-positive breast cancer patients for whom there is currently no treatment available.
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Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/patologia , Proteínas de Ciclo Celular/antagonistas & inibidores , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Maitansina/análogos & derivados , Proteínas Serina-Treonina Quinases/antagonistas & inibidores , Proteínas Proto-Oncogênicas/antagonistas & inibidores , Pteridinas/farmacologia , Trastuzumab/uso terapêutico , Ado-Trastuzumab Emtansina , Animais , Neoplasias da Mama/metabolismo , Proteína Quinase CDC2/metabolismo , Linhagem Celular Tumoral , Sinergismo Farmacológico , Feminino , Humanos , Maitansina/uso terapêutico , Camundongos , Fosforilação/efeitos dos fármacos , Proteínas Proto-Oncogênicas c-bcl-2/genética , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Receptor ErbB-2/metabolismo , Transdução de Sinais/efeitos dos fármacos , Ensaios Antitumorais Modelo de Xenoenxerto , Proteína bcl-X/genética , Proteína bcl-X/metabolismo , Quinase 1 Polo-LikeRESUMO
A single additive, a grafted copolymer, is designed to ensure the stability of suspensions of highly loaded iron oxide nanoparticles (IOPs) and to facilitate three-dimensional (3D) printing of these suspensions in the filament form. This poly (ethylene glycol)-grafted copolymer of N-[3(dimethylamino)propyl]methacrylamide and acrylic acid harnesses both electrostatic and steric repulsion to realize an optimum formulation for 3D printing. When used at 1.15 wt % (by the weight of IOPs), the suspension attains â¼81 wt % solid loading-96% of the theoretical limit as calculated by the Krieger-Dougherty equation. Rectangular, thick-walled toroidal, and thin-walled toroidal magnetic cores and a porous lattice structure are fabricated to demonstrate the utilization of this suspension as an ink for 3D printing. The electrical and magnetic properties of the magnetic cores are characterized through impedance spectroscopy (IS) and vibrating sample magnetometry (VSM), respectively. The IS indicates the possibility of utilizing wire-wound 3D printed cores as the inductive coils. The VSM verifies that the magnetic properties of IOPs before and after the ink formulation are kept almost unchanged because of the low dosage of the additive. This particle-targeted approach for the formulation of 3D printing inks allows embodiment of a fully aqueous system with utmost target material content.
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Calcium aluminate cement (CAC) suffers from loss of workability in less than an hour (~15 minutes) after first touch of water. Current superplasticizers that are utilized to modify the viscosity of cement admixtures are designed to target ordinary Portland cement (OPC). The high affinity between these superplasticizers and cement particles were found to be detrimental in CAC systems. Utilization of a monomer that, instead, facilitates gradual adsorption of a superplasticizer provides workability retention. For the first time in literature, we report a superplasticizer that caters to the properties of CAC such as high rate of surface development and surface charge. While neat CAC was almost unworkable after 1 hour, with the addition of only 0.4% of the optimized superplasticizer, 90% fluidity retention was achieved.
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Chiral mixed ligand silver nanoclusters were synthesized in the presence of a chiral and an achiral ligand. While the chiral ligand led mostly to the formation of nanoparticles, the presence of the achiral ligand drastically increased the yield of nanoclusters with enhanced chiral properties.
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This paper demonstrates the use of aqueous multiphase systems (MuPSs) as media for rate-zonal centrifugation to separate nanoparticles of different shapes and sizes. The properties of MuPSs do not change with time or during centrifugation; this stability facilitates sample collection after separation. A three-phase system demonstrates the separation of the reaction products (nanorods, nanospheres, and large particles) of a synthesis of gold nanorods, and enriches the nanorods from 48 to 99% in less than ten minutes using a benchtop centrifuge.
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This Communication demonstrates the generation of over 300 phase-separated systems-ranging from two to six phases-from mixtures of aqueous solutions of polymers and surfactants. These aqueous multiphase systems (MuPSs) form self-assembling, thermodynamically stable step-gradients in density using a common solvent, water. The steps in density between phases of a MuPS can be very small (Δρ ≈ 0.001 g/cm(3)), do not change over time, and can be tuned by the addition of co-solutes. We use two sets of similar objects, glass beads and pellets of different formulations of Nylon, to demonstrate the ability of MuPSs to separate mixtures of objects by differences in density. The stable interfaces between phases facilitate the convenient collection of species after separation. These results suggest that the stable, sharp step-gradients in density provided by MuPSs can enable new classes of fractionations and separations based on density.
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Polímeros/isolamento & purificação , Tensoativos/isolamento & purificação , Centrifugação com Gradiente de Concentração , Polímeros/química , Propriedades de Superfície , Tensoativos/química , Termodinâmica , Água/químicaRESUMO
The combination of simple Electrochemical Micro-Paper-based Analytical Devices (EµPADs) with commercially available glucometers allows rapid, quantitative electrochemical analysis of a number of compounds relevant to human health (e.g., glucose, cholesterol, lactate, and alcohol) in blood or urine.
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Automonitorização da Glicemia/instrumentação , Técnicas Eletroquímicas/instrumentação , Técnicas Analíticas Microfluídicas/instrumentação , Papel , Glicemia/análise , Automonitorização da Glicemia/métodos , Colesterol/sangue , Técnicas Eletroquímicas/métodos , Etanol/análise , Análise de Alimentos , Humanos , Ácido Láctico/sangue , Modelos Lineares , Técnicas Analíticas Microfluídicas/métodosRESUMO
This tutorial review provides an outlook on contact-based fabrication methods suitable for biomolecular platforms. Contact-based methods have emerged in response to serial and expensive fabrication techniques that built devices in a serial way, typically point by point or region by region. The review surveys the biological applications of microcontact printing and affinity contact printing. There is a special focus on DNA printing methods harnessing the supramolecular interactions between two complementary DNA strands.
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Microtecnologia/métodos , Animais , Humanos , Tinta , Análise de Sequência com Séries de Oligonucleotídeos , ImpressãoRESUMO
The construction of nanoporous membranes is of great technological importance for various applications, including catalyst supports, filters for biomolecule purification, environmental remediation and seawater desalination. A major challenge is the scalable fabrication of membranes with the desirable combination of good thermal stability, high selectivity and excellent recyclability. Here we present a self-assembly method for constructing thermally stable, free-standing nanowire membranes that exhibit controlled wetting behaviour ranging from superhydrophilic to superhydrophobic. These membranes can selectively absorb oils up to 20 times the material's weight in preference to water, through a combination of superhydrophobicity and capillary action. Moreover, the nanowires that form the membrane structure can be re-suspended in solutions and subsequently re-form the original paper-like morphology over many cycles. Our results suggest an innovative material that should find practical applications in the removal of organics, particularly in the field of oil spill cleanup.
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Poluição Ambiental/prevenção & controle , Compostos de Manganês/química , Membranas Artificiais , Nanoestruturas/química , Nanotecnologia/métodos , Nanotubos/química , Óleos/isolamento & purificação , Óxidos/química , Adsorção , MolhabilidadeRESUMO
The rapid development of molecular biology is creating a pressing need for arrays of biomolecules that are able to detect smaller and smaller volumes of analytes. This goal can be achieved by shrinking the average size and spacing of the arrays' constituent features. While bioarrays with dot size and spacing on the nanometer scale have been successfully fabricated via scanning probe microscopy-based techniques, such fabrication methods are serial in nature and consequently slow and expensive. Additionally, the development of truly small arrays able to analyze scarce volumes of liquids is hindered by the present use of optical detection, which sets the minimum dot spacing on the order of roughly half the excitation wavelength. Here, we show that supramolecular nanostamping, a recently introduced truly parallel method for the stamping of DNA features, can efficiently reproduce DNA arrays with features as small as 14 +/- 2 nm spaced 77 +/- 10 nm. Moreover, we demonstrate that hybridization of these nanoarrays can be detected using atomic force microscopy in a simple and scaleable way that additionally does not require labeling of the DNA strands.