Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 32
Filtrar
1.
Langmuir ; 38(48): 14623-14634, 2022 12 06.
Artículo en Inglés | MEDLINE | ID: mdl-36416530

RESUMEN

Fc γ receptors (FcγRs) are one of the structures that can initiate effector function for monoclonal antibodies. FcγRIa has the highest affinity toward IgG1-type monoclonal antibodies among all FcγRs. In this study, a comprehensive characterization was performed for FcγRIa as a potential affinity ligand for IgG1-type monoclonal antibody binding. The binding interactions were assessed with the SPR technique using different immobilization techniques such as EDC-NHS coupling, streptavidin-biotin interaction, and His-tagged FcγRIa capture. The His-tagged FcγRIa capture was the most convenient method based on assay repeatability. Next, a crude IgG1 sample and its fractions with different monomer contents obtained from protein A affinity chromatography were used to evaluate FcγRIa protein in terms of monoclonal antibody binding capacity. The samples were also compared with a protein A-immobilized chip (a frequently used affinity ligand) for IgG1 binding responses. The antibody binding capacity of the protein A-immobilized chip surface was significantly better than that of the FcγRIa-immobilized chip surface due to its 5 Ig binding domains. The antibody binding responses changed similarly with protein A depending on the monomer content of the sample. Finally, a different configuration was used to assess the binding affinity of free FcγRs (FcγRIa, FcγRIIa, and FcγRIIIa) to three different immobilized IgGs by immobilizing protein L to the chip surface. Unlike previous immobilization techniques tested where the FcγRIa was utilized as a ligand, nonimmobilized or free FcγRIa resulted in a significantly higher antibody binding response than free protein A. In this configuration, kinetics data of FcγRI revealed that the association rate (ka 50-80 × 105 M-1 s-1) increased in comparison to His capture method (1.9-2.4 × 105 M-1 s-1). In addition, the dissociation rate (kd 10-5 s-1) seemed slower over the His capture method (10-4 s-1) and provided stability on the chip surface during the dissociation phase. The KD values for FcγRIa were found in the picomolar range (2.1-10.33 pM from steady-state affinity analysis and 37.5-46.2 pM from kinetic analysis) for IgG1-type antibodies. FcγRIa possesses comparable ligand potential as well as protein A. Even though the protein A-immobilized surface bound more antibodies than the FcγRIa-captured surface, FcγRIa presented a significant antibody binding capacity in protein L configuration. The results suggest FcγRIa protein as a potential ligand for site-oriented immobilization of IgG1-type monoclonal antibodies, and it needs further performance investigation on different surfaces and interfaces for applications such as sensing and antibody purification.


Asunto(s)
Receptores de IgG , Proteína Estafilocócica A , Receptores de IgG/química , Receptores de IgG/metabolismo , Proteína Estafilocócica A/química , Proteína Estafilocócica A/metabolismo , Inmunoglobulina G/química , Ligandos , Cinética , Anticuerpos Monoclonales , Anticuerpos Inmovilizados , Unión Proteica
2.
Int J Mol Sci ; 22(22)2021 Nov 16.
Artículo en Inglés | MEDLINE | ID: mdl-34830231

RESUMEN

Food insecurity and malnutrition have reached critical levels with increased human population, climate fluctuations, water shortage; therefore, higher-yielding crops are in the spotlight of numerous studies. Abiotic factors affect the yield of staple food crops; among all, wheat stem sawfly (Cephus cinctus Norton) and orange wheat blossom midge (Sitodiplosis mosellana) are two of the most economically and agronomically harmful insect pests which cause yield loss in cereals, especially in wheat in North America. There is no effective strategy for suppressing this pest damage yet, and only the plants with intrinsic tolerance mechanisms such as solid stem phenotypes for WSS and antixenosis and/or antibiosis mechanisms for OWBM can limit damage. A major QTL and a causal gene for WSS resistance were previously identified in wheat, and 3 major QTLs and a causal gene for OWBM resistance. Here, we present a comparative analysis of coding and non-coding features of these loci of wheat across important cereal crops, barley, rye, oat, and rice. This research paves the way for our cloning and editing of additional WSS and OWBM tolerance gene(s), proteins, and metabolites.


Asunto(s)
Dípteros/patogenicidad , Resistencia a la Enfermedad/genética , Genoma de Planta , Himenópteros/patogenicidad , Enfermedades de las Plantas/genética , Sitios de Carácter Cuantitativo , Triticum/genética , Animales , Avena/genética , Avena/inmunología , Avena/parasitología , Mapeo Cromosómico/métodos , Dípteros/fisiología , Grano Comestible , Código Genético , Hordeum/genética , Hordeum/inmunología , Hordeum/parasitología , Humanos , Himenópteros/fisiología , Oryza/genética , Oryza/inmunología , Oryza/parasitología , Enfermedades de las Plantas/inmunología , Enfermedades de las Plantas/parasitología , Carácter Cuantitativo Heredable , Secale/genética , Secale/inmunología , Secale/parasitología , Especificidad de la Especie , Triticum/inmunología , Triticum/parasitología
3.
Mikrochim Acta ; 186(8): 563, 2019 07 24.
Artículo en Inglés | MEDLINE | ID: mdl-31338623

RESUMEN

Fluorescence resonance energy transfer, one of the most powerful phenomena for elucidating molecular interactions, has been extensively utilized as a biosensing tool to provide accurate information at the nanoscale. Numerous aptamer- and nanomaterial-based FRET bioassays has been developed for detection of a large variety of molecules. Affinity probes are widely used in biosensors, in which aptamers have emerged as advantageous biorecognition elements, due to their chemical and structural stability. Similarly, optically active nanomaterials offer significant advantages over conventional organic dyes, such as superior photophysical properties, large surface-to-volume ratios, photostability, and longer shelf life. In this report (with 175 references), the use of aptamer-modified nanomaterials as FRET couples is reviewed: quantum dots, upconverting nanoparticles, graphene, reduced graphene oxide, gold nanoparticles, molybdenum disulfide, graphene quantum dots, carbon dots, and metal-organic frameworks. Tabulated summaries provide the reader with useful information on the current state of research in the field. Graphical abstract Schematic representation of a fluorescence resonance energy transfer-based aptamer nanoprobe in the absence and presence of a given target molecule (analyte). Structures are not drawn to their original scales.

4.
BMC Genomics ; 18(1): 969, 2017 Dec 15.
Artículo en Inglés | MEDLINE | ID: mdl-29246190

RESUMEN

BACKGROUND: Drought is a lifestyle disease. Plant metabolomics has been exercised for understanding the fine-tuning of the potential pathways to surmount the adverse effects of drought stress. A broad spectrum of morphological and metabolic responses from seven Triticeae species including wild types with different drought tolerance/susceptibility level was investigated under control and water scarcity conditions. RESULTS: Significant morphological parameters measured were root length, surface area, average root diameter and overall root development. Principal Component Analysis, Partial Least-Squares-Discriminant Analysis and Hierarchical Cluster Analysis were applied to the metabolomic data obtained by Gas Chromatography-Mass Spectrometry technique in order to determine the important metabolites of the drought tolerance across seven different Triticeae species. The metabolites showing significant accumulation under the drought stress were considered as the key metabolites and correlated with potential biochemical pathways, enzymes or gene locations for a better understanding of the tolerance mechanisms. In all tested species, 45 significantly active metabolites with possible roles in drought stress were identified. Twenty-one metabolites out of forty-five including sugars, amino acids, organic acids and low molecular weight compounds increased in both leaf and root samples of TR39477, IG132864 and Bolal under the drought stress, contrasting to TTD-22, Tosunbey, Ligustica and Meyeri samples. Three metabolites including succinate, aspartate and trehalose were selected for further genome analysis due to their increased levels in TR39477, IG132864, and Bolal upon drought stress treatment as well as their significant role in energy producing biochemical pathways. CONCLUSION: These results demonstrated that the genotypes with high drought tolerance skills, especially wild emmer wheat, have a great potential to be a genetic model system for experiments aiming to validate metabolomics-genomics networks.


Asunto(s)
Sequías , Estrés Fisiológico , Triticum/metabolismo , Genes de Plantas , Genoma de Planta , Metabolómica , Hojas de la Planta/metabolismo , Raíces de Plantas/anatomía & histología , Raíces de Plantas/metabolismo , Poaceae/anatomía & histología , Poaceae/genética , Poaceae/crecimiento & desarrollo , Poaceae/metabolismo , Estrés Fisiológico/genética , Triticum/anatomía & histología , Triticum/genética , Triticum/crecimiento & desarrollo
5.
Analyst ; 142(6): 835-848, 2017 Mar 13.
Artículo en Inglés | MEDLINE | ID: mdl-28197569

RESUMEN

The development of microfabricated devices that will provide high-throughput quantitative data and high resolution in a fast, repeatable and reproducible manner is essential for plant biology research. Plants have been intensely explored since the beginning of humanity, especially for medical needs. However, plant biology research is still laborious, lacking the latest technological advancements in the laboratory practices. Microfabricated tools can provide a significant contribution to plant biology research since they require small volumes of samples and reagents with minimal cost and labor. Besides, they minimize the wet lab requirements while providing a parallel measurement platform for high-throughput data. Here, we have reviewed the cutting-edge microfabricated technologies developed for plant biology research. The description of the microfabricated device components, their integration with plant science and their substitution with the conventional techniques are presented. Our discussion on the challenges and future opportunities for scientists working at the fascinating intersection between plant science and engineering concludes this study.

6.
Acta Pol Pharm ; 74(2): 357-367, 2017 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-29624240

RESUMEN

New analytical methods have been developed and validated on high performance liquid chromatography (HPLC) to assess the assay, content uniformity and dissolution of immediate release candesartan cilexetil 32 mg tablets. Method development studies were performed on cyano column. Mobile phase of assay and content uniformity test consisted of mixture of 0.05 M phosphate buffer, pH 4.5 and methanol (40 : 60, v/v) adjusted to pH 4.0 with trifluoroacetic acid, whereas mobile phase of dissolution test consisted of mixture of I mM phosphate buffer and acetonitrile (50 : 50, v/v) adjusted to pH 2.0 with trifluoroacetic acid. Mobile phases were pumped at flow rate of 1.0 mL/min, ultraviolet-visible (UV) detector was operated at 254 nm, injection volume was set at 20 µL, column temperature was held at 25°C. Dissolution medium was 0.05 M phosphate buffer, pH 6.5 including 0.70% (w/v) polysorbate 20. Validation studies met acceptance criteria of system suitability, specificity, linearity and range, accuracy, precision, detection limit (LOD), quantitation limit (LOQ) and robustness parameters.


Asunto(s)
Bloqueadores del Receptor Tipo 1 de Angiotensina II/aislamiento & purificación , Bencimidazoles/análisis , Compuestos de Bifenilo/análisis , Cromatografía Líquida de Alta Presión , Tetrazoles/análisis , Bloqueadores del Receptor Tipo 1 de Angiotensina II/química , Bencimidazoles/química , Compuestos de Bifenilo/química , Tampones (Química) , Química Farmacéutica , Composición de Medicamentos , Liberación de Fármacos , Concentración de Iones de Hidrógeno , Límite de Detección , Modelos Lineales , Reproducibilidad de los Resultados , Solubilidad , Solventes/química , Comprimidos , Temperatura , Tetrazoles/química
7.
BMC Genomics ; 16: 453, 2015 Jun 13.
Artículo en Inglés | MEDLINE | ID: mdl-26070810

RESUMEN

BACKGROUND: The substantially large bread wheat genome, organized into highly similar three sub-genomes, renders genomic research challenging. The construction of BAC-based physical maps of individual chromosomes reduces the complexity of this allohexaploid genome, enables elucidation of gene space and evolutionary relationships, provides tools for map-based cloning, and serves as a framework for reference sequencing efforts. In this study, we constructed the first comprehensive physical map of wheat chromosome arm 5DS, thereby exploring its gene space organization and evolution. RESULTS: The physical map of 5DS was comprised of 164 contigs, of which 45 were organized into 21 supercontigs, covering 176 Mb with an N50 value of 2,173 kb. Fifty-eight of the contigs were larger than 1 Mb, with the largest contig spanning 6,649 kb. A total of 1,864 molecular markers were assigned to the map at a density of 10.5 markers/Mb, anchoring 100 of the 120 contigs (>5 clones) that constitute ~95 % of the cumulative length of the map. Ordering of 80 contigs along the deletion bins of chromosome arm 5DS revealed small-scale breaks in syntenic blocks. Analysis of the gene space of 5DS suggested an increasing gradient of genes organized in islands towards the telomere, with the highest gene density of 5.17 genes/Mb in the 0.67-0.78 deletion bin, 1.4 to 1.6 times that of all other bins. CONCLUSIONS: Here, we provide a chromosome-specific view into the organization and evolution of the D genome of bread wheat, in comparison to one of its ancestors, revealing recent genome rearrangements. The high-quality physical map constructed in this study paves the way for the assembly of a reference sequence, from which breeding efforts will greatly benefit.


Asunto(s)
Mapeo Contig/métodos , Duplicación de Gen , Reordenamiento Génico , Triticum/genética , Cromosomas de las Plantas , ADN de Plantas/análisis , Evolución Molecular , Mapeo Físico de Cromosoma/métodos
8.
Analyst ; 140(16): 5379-99, 2015 Aug 21.
Artículo en Inglés | MEDLINE | ID: mdl-26114391

RESUMEN

Aptamers are target specific ssDNA, RNA or peptide sequences generated by an in vitro selection and amplification method called SELEX (Systematic Evolution of Ligands by EXponential Enrichment), which involves repetitive cycles of binding, recovery and amplification steps. Aptamers have the ability to bind with a variety of targets such as drugs, proteins, heavy metals, and pathogens with high specificity and selectivity. Aptamers are similar to monoclonal antibodies regarding their binding affinities, but they offer a number of advantages over the existing antibody-based detection methods, which make the aptamers promising diagnostic and therapeutic tools for future biomedical and analytical applications. The aim of this review article is to provide an overview of the recent advancements in aptamer screening methods along with a concise description of the major application areas of aptamers including biomarker discovery, diagnostics, imaging and nanotechnology.


Asunto(s)
Aptámeros de Nucleótidos/aislamiento & purificación , Aptámeros de Nucleótidos/uso terapéutico , Técnica SELEX de Producción de Aptámeros/métodos , Técnica SELEX de Producción de Aptámeros/tendencias , Humanos
9.
Adv Colloid Interface Sci ; 333: 103298, 2024 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-39243484

RESUMEN

This review paper focuses on group IVB transition metal nitrides (TMNs) such as titanium nitride (TiN), zirconium nitride (ZrN), and hafnium nitride (HfN) and as alternative plasmonic materials to noble metals like gold and silver. It delves into the fabrication methods of these TMNs, particularly emphasizing thin film fabrication techniques like magnetron sputtering and atomic layer deposition, as well as nanostructure fabrication processes applied to these thin films. Overcoming the current fabrication and application-related challenges requires a deep understanding of the material properties, deposition techniques, and application requirements. Here, we discuss the impact of fabrication parameters on the properties of resulting films, highlighting the importance of aligning fabrication methods with practical application requirements for optimal performance. Additionally, we summarize and tabulate the most recent plasmonic applications of these TMNs in fields like biosensing, photovoltaic energy, and photocatalysis, contributing significantly to the current literature by consolidating knowledge on TMNs.

10.
Heliyon ; 9(9): e19469, 2023 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-37809995

RESUMEN

The controlled orientation of biomolecules on the sensor surface is crucial for achieving high sensitivity and accurate detection of target molecules in biosensing. FcγRI is an immune cell surface receptor for recognizing IgG-coated targets, such as opsonized pathogens or immune complexes. It plays a crucial role in T cell activation and internalization of the cargos, leading downstream signaling cascades. In this study, we repurposed the FcγRI as an analytical ligand molecule for site-oriented ADA capture, a monoclonal antibody-based biosimilar drug, on a plasmonic sensor surface and demonstrated the real-time detection of the corresponding analyte molecule, TNF-α. The study encompasses the analysis of comparative ligand behaviors on the surface, biosensor kinetics, concentration-dependent studies, and sensor specificity assays. The findings of this study suggest that FcγRI has a significant potential to serve as a universal ligand molecule for site-specific monoclonal antibody capture, and it can be used for biosensing studies, as it represents low nanomolar range affinity and excellent selectivity towards the target. However, there is still room for improvement in the surface stability and sensing response, and further studies are needed to reveal its performance on the monoclonal antibodies with various antigen binding sites and glycoforms.

11.
Curr Med Chem ; 30(8): 910-934, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-35156569

RESUMEN

Viral infections can cause fatal illnesses to humans as well as animals. Early detection of viruses is therefore crucial to provide effective treatment to patients. Recently, the Covid-19 pandemic has undoubtedly given an alarming call to develop rapid and sensitive detection platforms. The viral diagnostic tools need to be fast, affordable, and easy to operate with high sensitivity and specificity equivalent or superior to the currently used diagnostic methods. The present detection methods include direct detection of viral antigens or measuring the response of antibodies to viral infections. However, the sensitivity and quantification of the virus are still a significant challenge. Detection tools employing synthetic binding molecules like aptamers may provide several advantages over the conventional methods that use antibodies in the assay format. Aptamers are highly stable and tailorable molecules and are therefore ideal for detection and chemical sensing applications. This review article discusses various advances made in aptamer-based viral detection platforms, including electrochemical, optical, and colorimetric methods to detect viruses, specifically SARS-Cov-2. Considering the several advantages, aptamers could be game-changing in designing high-throughput biosensors for viruses and other biomedical applications in the future.


Asunto(s)
Aptámeros de Nucleótidos , COVID-19 , Virus , Animales , Humanos , SARS-CoV-2 , Pandemias , Anticuerpos , Biomarcadores
12.
ACS Appl Mater Interfaces ; 15(48): 55201-55231, 2023 Dec 06.
Artículo en Inglés | MEDLINE | ID: mdl-37994836

RESUMEN

The nanomaterial and related toolkit have promising applications for improving human health and well-being. Nanobased drug delivery systems use nanoscale materials as carriers to deliver therapeutic agents in a targeted and controlled manner, and they have shown potential to address issues associated with conventional drug delivery systems. They offer benefits for treating various illnesses by encapsulating or conjugating biological agents, chemotherapeutic drugs, and immunotherapeutic agents. The potential applications of this technology are vast; however, significant challenges exist to overcome such as safety issues, toxicity, efficacy, and insufficient capacity. This article discusses the latest developments in drug delivery systems, including drug release mechanisms, material toolkits, related design molecules, and parameters. The concluding section examines the limitations and provides insights into future possibilities.


Asunto(s)
Nanopartículas , Nanoestructuras , Humanos , Sistemas de Liberación de Medicamentos , Portadores de Fármacos
13.
Adv Colloid Interface Sci ; 322: 103035, 2023 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-37931382

RESUMEN

Surface-functionalized nanostructures are at the forefront of biotechnology, providing new opportunities for biosensors, drug delivery, therapy, and bioimaging applications. The modification of nanostructures significantly impacts the performance and success of various applications by enabling selective and precise targeting. This review elucidates widely practiced surface modification strategies, including click chemistry, cross-coupling, silanization, aldehyde linkers, active ester chemistry, maleimide chemistry, epoxy linkers, and other protein and DNA-based methodologies. We also delve into the application-focused landscape of the nano-bio interface, emphasizing four key domains: therapeutics, biosensing, environmental monitoring, and point-of-care technologies, by highlighting prominent studies. The insights presented herein pave the way for further innovations at the intersection of nanotechnology and biotechnology, providing a useful handbook for beginners and professionals. The review draws on various sources, including the latest research articles (2018-2023), to provide a comprehensive overview of the field.


Asunto(s)
Técnicas Biosensibles , Nanoestructuras , Nanoestructuras/química , Nanotecnología/métodos , Técnicas Biosensibles/métodos , Biotecnología , Proteínas
14.
ACS Appl Nano Mater ; 6(22): 20612-20622, 2023 Nov 24.
Artículo en Inglés | MEDLINE | ID: mdl-38037604

RESUMEN

Group IVB metal nitrides have attracted great interest as alternative plasmonic materials. Among them, titanium nitride (TiN) stands out due to the ease of deposition and relative abundance of Ti compared to those of Zr and Hf metals. Even though they do not have Au or Ag-like plasmonic characteristics, they offer many advantages, from high mechanical stability to refractory behavior and complementary metal oxide semiconductor-compatible fabrication to tunable electrical/optical properties. In this study, we utilized reactive RF magnetron sputtering to deposit plasmonic TiN thin films. The flow rate and ratio of Ar/N2 and oxygen scavenging methods were optimized to improve the plasmonic performance of TiN thin films. The stoichiometry and structure of the TiN thin films were thoroughly investigated to assess the viability of the optimized operation procedures. To assess the plasmonic performance of TiN thin films, periodic nanohole arrays were perforated on TiN thin films by using electron beam lithography and reactive ion etching methods. The resulting TiN periodic nanohole array with varying periods was investigated by using a custom microspectroscopy setup for both reflection and transmission characteristics in various media to underline the efficacy of TiN for refractometric sensing.

15.
Emergent Mater ; 5(1): 105-132, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35284783

RESUMEN

Agricultural pollutants are harmful components threatening human health, wildlife, the environment, and the ecosystem. To avoid their exposure, developing prevention and detection systems with high sensitivity and selectivity is required. Most conventional methods, including molecular and chromatographic techniques, cannot be adopted for outdoor on-site detection even though they can provide sensitive and selective detection. Thus, detection platforms that can provide on-site detection via miniaturized and high throughput systems should be developed. As an alternative method, surface-enhanced Raman scattering (SERS) provides unique information about the substances in the presence of plasmonic nanostructures, and it can be portable with the use of portable detection systems and spectrometers. In this study, on-site detection of agricultural pollutants through SERS is reviewed. Three different types of agricultural pollutants were pointed out. On-site detection of biological pollutants, including bacteria and viruses, is reviewed as the first type of pollutant. As a second type, the detection of pesticides, antibiotics, and additives are focused on as chemical pollutants. The third group includes the detection of microplastics and also nanoparticles from the environment.

16.
J Biotechnol ; 354: 10-20, 2022 Aug 10.
Artículo en Inglés | MEDLINE | ID: mdl-35700936

RESUMEN

Nucleic acid aptamers are target-specific oligonucleotides selected from combinatorial libraries through an iterative in vitro screening process known as Systemic Evolution of Ligands by Exponential Enrichment (SELEX). In this report, the selection of bacteria differentiating ssDNA aptamer candidates from a combinatorial library through the whole-cell SELEX method was performed. The enriched SELEX pool was sequenced using Illumina Next-Generation Sequencing (NGS) technology and analyzed for the most abundant sequences using CLC Genomics Workbench. The sequencing data resulted in several oligonucleotide families from which three individual sequences were chosen per SELEX based on the copy numbers. The binding performance of the selected aptamers was assessed by flow cytometry and fluorescence spectroscopy, and the binding constants were estimated using binding saturation curves. Varying results were obtained from two independent SELEX procedures where the SELEX against the model gram-negative bacterium Escherichia coli provided more selective sequences while the SELEX library used against gram-positive bacterium Listeria monocytogenes did not evolve as expected. The sequences that emerged from E. coli SELEX were shown to bind Lipopolysaccharide residues (LPS) and inhibit LPS-induced macrophage polarization. Thus, it can be said that, performed whole-cell SELEX could be resulted as the selection of aptamers which can bind LPS and inhibit LPS induced inflammation response and thus can be candidates for the inhibition of bacterial infections. In future studies, the selected aptamer sequences could be structurally and chemically modified and exploited as potential diagnostic tools and therapeutic agents as LPS antagonists.


Asunto(s)
Aptámeros de Nucleótidos , Técnica SELEX de Producción de Aptámeros , Aptámeros de Nucleótidos/química , Escherichia coli/genética , Escherichia coli/metabolismo , Biblioteca de Genes , Humanos , Ligandos , Lipopolisacáridos , Técnica SELEX de Producción de Aptámeros/métodos
17.
Pharmaceutics ; 14(8)2022 Jul 28.
Artículo en Inglés | MEDLINE | ID: mdl-36015197

RESUMEN

Avastin® is a humanized recombinant monoclonal antibody used to treat cancer by targeting VEGF-A to inhibit angiogenesis. SIMAB054, an Avastin® biosimilar candidate developed in this study, showed a different charge variant profile than its innovator. Thus, it is fractionated into acidic, main, and basic isoforms and collected physically by Cation Exchange Chromatography (CEX) for a comprehensive structural and functional analysis. The innovator product, fractionated into the same species and collected by the same method, is used as a reference for comparative analysis. Ultra-Performance Liquid Chromatography (UPLC) ESI-QToF was used to analyze the modifications leading to charge heterogeneities at intact protein and peptide levels. The C-terminal lysine clipping and glycosylation profiles of the samples were monitored by intact mAb analysis. The post-translational modifications, including oxidation, deamidation, and N-terminal pyroglutamic acid formation, were determined by peptide mapping analysis in the selected signal peptides. The relative binding affinities of the fractionated charge isoforms against the antigen, VEGF-A, and the neonatal receptor, FcRn, were revealed by Surface Plasmon Resonance (SPR) studies. The results show that all CEX fractions from the innovator product and the SIMAB054 shared the same structural variants, albeit in different ratios. Common glycoforms and post-translational modifications were the same, but at different percentages for some samples. The dissimilarities were mostly originating from the presence of extra C-term Lysin residues, which are prone to enzymatic degradation in the body, and thus they were previously assessed as clinically irrelevant. Another critical finding was the presence of different glyco proteoforms in different charge species, such as increased galactosylation in the acidic and afucosylation in the basic species. SPR characterization of the isolated charge variants further confirmed that basic species found in the CEX analyses of the biosimilar candidate were also present in the innovator product, although at lower amounts. The charge variants' in vitro antigen- and neonatal receptor-binding activities varied amongst the samples, which could be further investigated in vivo with a larger sample set to reveal the impact on the pharmacokinetics of drug candidates. Minor structural differences may explain antigen-binding differences in the isolated charge variants, which is a key parameter in a comparability exercise. Consequently, such a biosimilar candidate may not comply with high regulatory standards unless the binding differences observed are justified and demonstrated not to have any clinical impact.

18.
Emergent Mater ; 4(1): 211-229, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33615139

RESUMEN

The rapid worldwide spread of the COVID-19 pandemic, caused by the severe acute respiratory SARS-CoV-2, has created an urgent need for its diagnosis and treatment. As a result, many researchers have sought to find the most efficient and appropriate methods to detect and treat the SARS-CoV-2 virus over the past few months. Real-time reverse-transcriptase polymerase chain reaction (RT-PCR) testing is currently used as one of the most reliable methods to detect the new virus; however, this method is time-consuming, labor-intensive, and requires trained laboratory workers. Moreover, despite its high sensitivity and specificity, false negatives are reported, especially in non-nasopharyngeal swab samples that yield lower viral loads. Therefore, designing and employing faster and more reliable methods seems necessary. In recent years, many attempts have been made to fabricate various nanomaterial-based biosensors to detect viruses and bacteria in clinical samples. The use of nanomaterials plays a significant role in improving the performance of biosensors. Plasmonic biosensors, field-effect transistor (FET)-based biosensors, electrochemical biosensors, and reverse transcription loop-mediated isothermal amplification (RT-LAMP) methods are only some of the effective ways to detect viruses. However, to use these biosensors to detect the SARS-CoV-2 virus, modifications must be performed to increase sensitivity and speed of testing due to the rapidly spreading nature of SARS-CoV-2, which requires an early point of care detection and treatment for pandemic control. Several studies have been carried out to show the nanomaterial-based biosensors' performance and success in detecting the novel virus. The limit of detection, accuracy, selectivity, and detection speed are some vital features that should be considered during the design of the SARS-CoV-2 biosensors. This review summarizes various nanomaterials-based sensor platforms to detect the SARS-CoV-2, and their design, advantages, and limitations.

19.
Biosens Bioelectron ; 172: 112752, 2021 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-33126180

RESUMEN

A fast and accurate self-testing tool for COVID-19 diagnosis has become a prerequisite to comprehend the exact number of cases worldwide and to take medical and governmental actions accordingly. SARS-CoV-2 (formerly, 2019-nCoV) infection was first reported in Wuhan (China) in December 2019, and then it has rapidly spread around the world, causing ~14 million active cases with ~582,000 deaths as of July 2020. The diagnosis tools available so far have been based on a) viral gene detection, b) human antibody detection, and c) viral antigen detection, among which the viral gene detection by RT-PCR has been found as the most reliable technique. In this report, the current SARS-CoV-2 detection kits, exclusively the ones that were issued an "Emergency Use Authorization" from the U.S. Food and Drug Administration, were discussed. The key structural components of the virus were presented to provide the audience with an understanding of the scientific principles behind the testing tools. The methods that are still in the early research state were also reviewed in a subsection based on the reports available so far.


Asunto(s)
Técnicas Biosensibles/métodos , Prueba de COVID-19/métodos , COVID-19/diagnóstico , Anticuerpos Antivirales/análisis , Antígenos Virales/análisis , Técnicas Biosensibles/instrumentación , COVID-19/inmunología , COVID-19/virología , Prueba de Ácido Nucleico para COVID-19/instrumentación , Prueba de Ácido Nucleico para COVID-19/métodos , Prueba Serológica para COVID-19/instrumentación , Prueba Serológica para COVID-19/métodos , Prueba de COVID-19/instrumentación , Genoma Viral , Humanos , Pandemias , SARS-CoV-2/química , SARS-CoV-2/genética , SARS-CoV-2/inmunología
20.
Plants (Basel) ; 10(5)2021 May 16.
Artículo en Inglés | MEDLINE | ID: mdl-34065739

RESUMEN

Pan-genomes are efficient tools for the identification of conserved and varying genomic sequences within lineages of a species. Investigating genetic variations might lead to the discovery of genes present in a subset of lineages, which might contribute into beneficial agronomic traits such as stress resistance or yield. The content of varying genomic regions in the pan-genome could include protein-coding genes as well as microRNA(miRNAs), small non-coding RNAs playing key roles in the regulation of gene expression. In this study, we performed in silico miRNA identification from the genomic sequences of 54 lineages of Brachypodium distachyon, aiming to explore varying miRNA contents and their functional interactions. A total of 115 miRNA families were identified in 54 lineages, 56 of which were found to be present in all lineages. The miRNA families were classified based on their conservation among lineages and potential mRNA targets were identified. Obtaining information about regulatory mechanisms stemming from these miRNAs offers strong potential to provide a better insight into the complex traits that were potentially present in some lineages. Future work could lead us to introduce these traits to different lineages or other economically important plant species in order to promote their survival in different environmental conditions.

SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA