Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 8.253
Filtrar
1.
Yakugaku Zasshi ; 144(3): 275-283, 2024.
Artigo em Japonês | MEDLINE | ID: mdl-38432937

RESUMO

Molecular oxygen plays essential roles in aerobic organisms as a terminal electron acceptor in the electron transport chain in mitochondria. The intracellular oxygen concentration of the entire body is strictly regulated by a balance between the supply of oxygen from blood vessels and the consumption of oxygen in mitochondria. The disruption of oxygen homeostasis in the body often results in serious pathologies such as cancer, cerebral infarction, and chronic kidney disease, and thus considerable effort has been devoted to the development of suitable techniques allowing the qualitative and quantitative detection of tissue oxygen levels. This review focuses on recent advances in the visualization of oxygen levels in tissue based on phosphorescence lifetime measurements using exogenously small molecular oxygen probes. Specially, I introduce the principle of oxygen sensing by means of phosphorescence quenching, recent advances in intracellular and intravascular oxygen probes based on iridium(III) complexes, a system for measuring phosphorescence lifetime combined with confocal scanning microscopy, and the applications of these technologies to in vivo oxygen measurements, emphasizing the usefulness of iridium(III) complexes as biological oxygen probes.


Assuntos
Infarto Cerebral , Irídio , Humanos , Microscopia Confocal , Medições Luminescentes , Sondas Moleculares , Oxigênio
2.
Bioorg Chem ; 145: 107193, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38442611

RESUMO

Immunotherapy has brought great benefits to cancer patients, but only some patients benefit from it. Noninvasive, real-time and dynamic monitoring of the effectiveness of immunotherapy through PET imaging may provide assistance for the treatment plan of immunotherapy. In this study, we designed and synthesized a new targeted PD-L1 peptide NOTA-PEG2-Asp2-PDL1P, which was labeled with nuclide 18F to obtain a new imaging agent [18F]AlF-NOTA-PEG2-Asp2-PDL1P. The total radiochemical yield of [18F]AlF-NOTA-PEG2-Asp2-PDL1P was 13.7 % (Uncorrected radiochemical yield, n > 5). [18F]AlF-NOTA-PEG2-Asp2-PDL1P achieved high radiochemical purity (>95 %) with a molar activity more than 51.2 GBq/µmol. [18F]AlF-NOTA-PEG2-Asp2-PDL1P exhibited good hydrophilicity and had good stability both in vivo and in vitro, it can specifically targets B16F10 tumor with PD-L1 expression, and had a relatively high retention in tumor, a relatively fast clearance in vivo and a higher tumor-to-non-target ratio, all of which could make [18F]AlF-NOTA-PEG2-Asp2-PDL1P a potential tracer for PD-L1 prediction before clinical immunotherapy.


Assuntos
Compostos Heterocíclicos com 1 Anel , Compostos Heterocíclicos , Neoplasias , Humanos , Compostos Heterocíclicos/química , Sondas Moleculares , Antígeno B7-H1/metabolismo , Radioisótopos de Flúor/química , Tomografia por Emissão de Pósitrons/métodos , Compostos Radiofarmacêuticos/química , Linhagem Celular Tumoral
3.
Anal Chem ; 96(11): 4632-4638, 2024 Mar 19.
Artigo em Inglês | MEDLINE | ID: mdl-38457631

RESUMO

Superoxide anion (O2•-) plays a pivotal role in the generation of other reactive oxygen species within the body and is closely linked to epilepsy. Despite this connection, achieving precise imaging of O2•- during epilepsy pathology remains a formidable challenge. Herein, we develop an activatable molecular probe, CL-SA, to track the fluctuation of the level of O2•- in epilepsy through simultaneous fluorescence imaging and chemiluminescence sensing. The developed probe CL-SA demonstrated its efficacy in imaging of O2•- in neuronal cells, showcasing its dual optical imaging capability for O2•- in vitro. Furthermore, CL-SA was successfully used to observe aberrantly expressed O2•- in a mouse model of epilepsy. Overall, CL-SA provides us with a valuable tool for chemical and biomedical studies of O2•-, promoting the investigation of O2•- fluctuations in epilepsy, as well as providing a reliable means to explore the diagnosis and therapy of epilepsy.


Assuntos
Sondas Moleculares , Superóxidos , Camundongos , Animais , Humanos , Espécies Reativas de Oxigênio , Células Hep G2 , Imagem Óptica/métodos , Corantes Fluorescentes/química
4.
Radiol Cardiothorac Imaging ; 6(2): e230098, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38512024

RESUMO

Purpose To develop an approach for in vivo detection of interstitial cardiac fibrosis using PET with a peptide tracer targeting proteolyzed collagen IV (T-peptide). Materials and Methods T-peptide was conjugated to the copper chelator MeCOSar (chemical name, 5-(8-methyl-3,6,10,13,16,19-hexaaza-bicyclo[6.6.6]icosan-1-ylamino)-5-oxopentanoic acid) and radiolabeled with copper 64 (64Cu). PET/CT scans were acquired following intravenous delivery of 64Cu-T-peptide-MeCOSar (0.25 mg/kg; 18 MBq ± 2.7 [SD]) to male transgenic mice overexpressing ß2-adrenergic receptors with intermediate (7 months of age; n = 4 per group) to severe (10 months of age; n = 11 per group) cardiac fibrosis and their wild-type controls. PET scans were also performed following coadministration of the radiolabeled probe with nonlabeled T-peptide in excess to confirm binding specificity. PET data were analyzed by t tests for static scans and analysis of variance tests (one- or two-way) for dynamic scans. Results PET/CT scans revealed significantly elevated (2.24-4.26-fold; P < .05) 64Cu-T-peptide-MeCOSar binding in the fibrotic hearts of aged transgenic ß2-adrenergic receptor mice across the entire 45-minute acquisition period compared with healthy controls. The cardiac tracer accumulation and presence of diffuse cardiac fibrosis in older animals were confirmed by gamma counting (P < .05) and histologic evaluation, respectively. Coadministration of a nonradiolabeled probe in excess abolished the elevated radiotracer binding in the aged transgenic hearts. Importantly, PET tracer accumulation was also detected in younger (7 months of age) transgenic mice with intermediate cardiac fibrosis, although this was only apparent from 20 minutes following injection (1.6-2.2-fold binding increase; P < .05). Conclusion The T-peptide PET tracer targeting proteolyzed collagen IV provided a sensitive and specific approach of detecting diffuse cardiac fibrosis at varying degrees of severity in a transgenic mouse model. Keywords: Diffuse Cardiac Fibrosis, Molecular Peptide Probe, Molecular Imaging, PET/CT © RSNA, 2024.


Assuntos
Cobre , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada , Masculino , Animais , Camundongos , Sondas Moleculares , Tomografia por Emissão de Pósitrons , Imagem Molecular , Camundongos Transgênicos , Colágeno Tipo IV , Fibrose , Peptídeos
5.
ACS Sens ; 9(2): 995-1003, 2024 Feb 23.
Artigo em Inglês | MEDLINE | ID: mdl-38334979

RESUMO

For Raman hyperspectral detection and imaging in live cells, it is very desirable to create novel probes with strong and unique Raman vibrations in the biological silent region (1800-2800 cm-1). The use of molecular probes in Raman imaging is a relatively new technique in subcellular research; however, it is developing very rapidly. Compared with the label-free method, it allows for a more sensitive and selective visualization of organelles within a single cell. Biological systems are incredibly complex and heterogeneous. Directly visualizing biological structures and activities at the cellular and subcellular levels remains by far one of the most intuitive and powerful ways to study biological problems. Each organelle plays a specific and essential role in cellular processes, but importantly for cells to survive, mitochondrial function must be reliable. Motivated by earlier attempts and successes of biorthogonal chemical imaging, we develop a tool supporting Raman imaging of cells to track biochemical changes associated with mitochondrial function at the cellular level in an in vitro model. In this work, we present a newly synthesized highly sensitive RAR-BR Raman probe for the selective imaging of mitochondria in live endothelial cells.


Assuntos
Células Endoteliais , Mitocôndrias , Humanos , Mitocôndrias/química , Organelas , Sondas Moleculares , Diagnóstico por Imagem
6.
ACS Nano ; 18(6): 5167-5179, 2024 Feb 13.
Artigo em Inglês | MEDLINE | ID: mdl-38301048

RESUMO

Elucidation of biological phenomena requires imaging of microenvironments in vivo. Although the seamless visualization of in vivo hypoxia from the level of whole-body to single-cell has great potential to discover unknown phenomena in biological and medical fields, no methodology for achieving it has been established thus far. Here, we report the whole-body and whole-organ imaging of hypoxia, an important microenvironment, at single-cell resolution using activatable covalent fluorescent probes compatible with tissue clearing. We initially focused on overcoming the incompatibility of fluorescent dyes and refractive index matching solutions (RIMSs), which has greatly hindered the development of fluorescent molecular probes in the field of tissue clearing. The fluorescent dyes compatible with RIMS were then incorporated into the development of activatable covalent fluorescent probes for hypoxia. We combined the probes with tissue clearing, achieving comprehensive single-cell-resolution imaging of hypoxia in a whole mouse body and whole organs.


Assuntos
Corantes Fluorescentes , Imageamento Tridimensional , Animais , Camundongos , Imageamento Tridimensional/métodos , Sondas Moleculares , Hipóxia/diagnóstico por imagem , Imagem Óptica/métodos
7.
Bioconjug Chem ; 35(2): 265-275, 2024 02 21.
Artigo em Inglês | MEDLINE | ID: mdl-38340041

RESUMO

Despite significant progress in cancer imaging and treatment over the years, early diagnosis and metastasis detection remain a challenge. Molecular magnetic resonance imaging (MRI), with its high resolution, can be well adapted to fulfill this need, requiring the design of contrast agents which target specific tumor biomarkers. Netrin-1 is an extracellular protein overexpressed in metastatic breast cancer and implicated in tumor progression and the appearance of metastasis. This study focuses on the design and preclinical evaluation of a novel Netrin-1-specific peptide-based MRI probe, GdDOTA-KKTHDAVR (Gd-K), to visualize metastatic breast cancer. The targeting peptide sequence was identified based on the X-ray structure of the complex between Netrin-1 and its transmembrane receptor DCC. Molecular docking simulations support the probe design. In vitro studies evidenced submicromolar affinity of Gd-K for Netrin-1 (KD = 0.29 µM) and good MRI efficacy (proton relaxivity, r1 = 4.75 mM-1 s-1 at 9.4 T, 37 °C). In vivo MRI studies in a murine model of triple-negative metastatic breast cancer revealed successful tumor visualization at earlier stages of tumor development (smaller tumor volume). Excellent signal enhancement, 120% at 2 min and 70% up to 35 min post injection, was achieved (0.2 mmol/kg injected dose), representing a reasonable imaging time window and a superior contrast enhancement in the tumor as compared to Dotarem injection.


Assuntos
Biomarcadores Tumorais , Neoplasias de Mama Triplo Negativas , Camundongos , Humanos , Animais , Sondas Moleculares , Netrina-1 , Simulação de Acoplamento Molecular , Meios de Contraste/química , Peptídeos , Imageamento por Ressonância Magnética/métodos
8.
Chem Commun (Camb) ; 60(22): 3047-3050, 2024 Mar 12.
Artigo em Inglês | MEDLINE | ID: mdl-38376492

RESUMO

A novel AIEgen molecular probe (N-3QL) with typical AIE effects, good biocompatibility, lysosome targeting, pH activation, excellent photostability, and high brightness was synthesized using two simple synthetic steps. Spectroscopic and cytotoxicity experiments indicate that N-3QL can not only be used for the dynamic monitoring of cancer cell lysosomes, but also for photodynamic therapy (PDT) ablation of cancer cells.


Assuntos
Fotoquimioterapia , Fotoquimioterapia/métodos , Sondas Moleculares/análise , Concentração de Íons de Hidrogênio , Lisossomos/química
9.
J Am Chem Soc ; 146(10): 6830-6836, 2024 Mar 13.
Artigo em Inglês | MEDLINE | ID: mdl-38418383

RESUMO

Mechanical forces are crucial for biological processes such as T cell antigen recognition. A suite of molecular tension probes to measure pulling forces have been reported over the past decade; however, there are no reports of molecular probes for measuring compressive forces, representing a gap in the current mechanobiology toolbox. To address this gap, we report a molecular compression reporter using pseudostable hairpins (M-CRUSH). The design principle was based on a pseudostable DNA structure that folds in response to an external compressive force. We created a library of DNA stem-loop hairpins with varying thermodynamic stability, and then used Förster Resonance Energy Transfer (FRET) to quantify hairpin folding stability as a function of temperature and crowding. We identified an optimal pseudostable DNA hairpin highly sensitive to molecular crowding that displayed a shift in melting temperature (Tm) of 7 °C in response to a PEG crowding agent. When immobilized on surfaces, this optimized DNA hairpin showed a 29 ± 6% increase in FRET index in response to 25% w/w PEG 8K. As a proof-of-concept demonstration, we employed M-CRUSH to map the compressive forces generated by primary naïve T cells. We noted dynamic compressive forces that were highly sensitive to antigen presentation and coreceptor engagement. Importantly, mechanical forces are generated by cytoskeletal protrusions caused by acto-myosin activity. This was confirmed by treating cells with cytoskeletal inhibitors, which resulted in a lower FRET response when compared to untreated cells. Furthermore, we showed that M-CRUSH signal is dependent on probe density with greater density probes showing enhanced signal. Finally, we demonstrated that M-CRUSH probes are modular and can be applied to different cell types by displaying a compressive signal observed under human platelets. M-CRUSH offers a powerful tool to complement tension sensors and map out compressive forces in living systems.


Assuntos
DNA , Fenômenos Mecânicos , Humanos , DNA/química , Linfócitos T , Termodinâmica , Sondas Moleculares
10.
Biomacromolecules ; 25(2): 990-996, 2024 Feb 12.
Artigo em Inglês | MEDLINE | ID: mdl-38262046

RESUMO

Hydrazine-mediated formation of 1,4-phthalazinedione analogues from phthalimide-like components has been utilized to formulate fluorescent probe NorTh. A turn-on fluorescent process has been evaluated to detect hydrazine in a highly selective manner by a small molecular probe NorTh and its homopolymer Poly-NorTh. Both these probes have been evaluated as excellent candidates for nanomolar level detection of hydrazine with a time frame of <15 min, which is rapid in terms of real application. Due to the reaction-based detection process, we have achieved high selectivity for our probes toward the identification of hydrazine in the presence of metal ions, anions, amino acids, and various amines. Limit of detection values are 16 and 35 nM for NorTh and Poly-NorTh, respectively, which are well below the permissible limit given by WHO and EPA. Poly-NorTh has been utilized to detect hydrazine in environmental water samples, soil samples, and biological samples to establish the applicability of our probes in real-field scenarios. We introduce an easy-to-synthesize, cheap, and small molecular probe and its polymer for ultrafast, highly selective, and sensitive detection of hydrazine in all possible mediums to counter the hydrazine toxicity through fluorescence turn-on signal output.


Assuntos
Corantes Fluorescentes , Hidrazinas , Plásticos , Corantes Fluorescentes/química , Hidrazinas/química , Sondas Moleculares , Espectrometria de Fluorescência
11.
Analyst ; 149(4): 989-1001, 2024 Feb 12.
Artigo em Inglês | MEDLINE | ID: mdl-38226461

RESUMO

During a stress condition, the human body synthesizes catecholamine neurotransmitters and specific hormones (called "stress hormones"), the most important of which is cortisol. The monitoring of cortisol levels is extremely important for controlling the stress levels. For this reason, it has important medical applications. Common analytical methods (HPLC, GC-MS) cannot be used in real life due to the bulkiness of the instruments and the necessity of specialized operators. Molecular probes solve this problem. This review aims to provide a description of recent developments in this field, focusing on the analytical aspects and the possibility to obtain real practical devices from these molecular probes.


Assuntos
Catecolaminas , Hidrocortisona , Humanos , Sondas Moleculares , Neurotransmissores , Cromatografia Gasosa-Espectrometria de Massas
12.
Chemistry ; 30(11): e202303506, 2024 Feb 21.
Artigo em Inglês | MEDLINE | ID: mdl-38212242

RESUMO

ß2 -adrenergic receptor (ß2 -AR) agonists are used for the treatment of asthma and chronic obstructive pulmonary disease, but also play a role in other complex disorders including cancer, diabetes and heart diseases. As the cellular and molecular mechanisms in various cells and tissues of the ß2 -AR remain vastly elusive, we developed tools for this investigation with high temporal and spatial resolution. Several photoswitchable ß2 -AR agonists with nanomolar activity were synthesized. The most potent agonist for ß2 -AR with reasonable switching is a one-digit nanomolar active, trans-on arylazopyrazole-based adrenaline derivative and comprises valuable photopharmacological properties for further biological studies with high structural accordance to the native ligand adrenaline.


Assuntos
Adrenérgicos , Agonistas de Receptores Adrenérgicos beta 2 , Agonistas de Receptores Adrenérgicos beta 2/farmacologia , Sondas Moleculares , Receptores Adrenérgicos beta 2/química , Epinefrina/farmacologia , Transdução de Sinais
13.
Eur J Med Chem ; 266: 116134, 2024 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-38266552

RESUMO

PURPOSE: Claudin 18.2 (CLDN18.2), due to its highly selective expression in tumor cells, has made breakthrough progress in clinical research and is expected to be integrated into routine tumor diagnosis and treatment. METHODS: In this research, we obtained an scFv-Fc fusion protein (SF106) targeting CLDN18.2 through hybridoma technology. The scFv-Fc fusion protein was labeled with radioactive isotopes (124I and 177Lu) to generate the radio-probes. The targeting and specificity of the radio-probes were tested in cellular models, and its diagnostic and therapeutic potential was further evaluated in tumor-bearing models. RESULTS: The molecular probes [124I]I-SF106 and [177Lu]Lu-DOTA-SF106 possess high radiochemical purity (RCP, 98.18 ± 0.93 % and 97.05 ± 1.1 %) and exhibit good stability in phosphate buffer saline and 5 % human serum albumin (92.44 ± 4.68 % and 91.03 ± 2.42 % at 120 h). [124I]I-SF106 uptake in cells expressing CLDN18.2 was well targeted and specific, and the dissociation constant was 17.74 nM [124I]I-SF106 micro-PET imaging showed that the maximum standardized uptake value (SUVmax) was significantly higher than CLDN18.2-negative tumors (1.83 ± 0.02 vs. 1.23 ± 0.04, p < 0.001). The maximum uptake was attained in tumors expressing CLDN18.2 at 48 h after injection. [124I]I-SF106 and [177Lu]Lu-DOTA-SF106 dosimetric study showed that the effective dose in humans complies with the medical safety standards required for their clinical application. The results of treatment experiments showed that 3 MBq of [177Lu]Lu-DOTA-SF106 in CLDN18.2-expressing tumor-bearing mice could significantly inhibit tumor growth. CONCLUSION: These results indicate that radionuclide-labeled scFv-Fc molecular probes ([124I]I-SF106 and [177Lu]Lu-DOTA-SF106) provide a new possibility for the diagnosis and treatment of CLDN18.2-positive cancer patients in clinical practice.


Assuntos
Neoplasias , Compostos Radiofarmacêuticos , Humanos , Camundongos , Animais , Compostos Radiofarmacêuticos/farmacologia , Compostos Radiofarmacêuticos/uso terapêutico , Neoplasias/diagnóstico por imagem , Neoplasias/terapia , Albumina Sérica Humana , Radioisótopos do Iodo , Sondas Moleculares , Linhagem Celular Tumoral , Claudinas
14.
PLoS One ; 19(1): e0296847, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38190402

RESUMO

Molecular breeding methods, such as marker-assisted selection and genomic selection, require high-throughput and cost-effective methods for isolating genomic DNA from plants, specifically from crop tissue or seed with high polysaccharides, lipids, and proteins. A quick and inexpensive high-throughput method for isolating genomic DNA from seed and leaf tissue from multiple crops was tested with a DNA isolation method that combines CTAB extraction buffer and lab-made SA-coated magnetic nanoparticles. This method is capable of isolating quality genomic DNA from leaf tissue and seeds in less than 2 hours with fewer steps than a standard CTAB extraction method. The yield of the genomic DNA was 582-729 ng per 5 leaf discs or 216-1869 ng per seed in soybean, 2.92-62.6 ng per 5 leaf discs or 78.9-219 ng per seed in wheat, and 30.9-35.4 ng per 5 leaf discs in maize. The isolated DNA was tested with multiple molecular breeding methods and was found to be of sufficient quality and quantity for PCR and targeted genotyping by sequencing methods such as molecular inversion probes (MIPs). The combination of SA-coated magnetic nanoparticles and CTAB extraction buffer is a fast, simple, and environmentally friendly, high-throughput method for both leaf tissues and seed(s) DNA preparation at low cost per sample. The DNA obtained from this method can be deployed in applied breeding programs for marker-assisted selection or genomic selection.


Assuntos
Nanopartículas de Magnetita , Cetrimônio , Melhoramento Vegetal , Sementes/genética , Inversão Cromossômica , Sondas Moleculares
15.
Nucleic Acids Res ; 52(3): 1272-1289, 2024 Feb 09.
Artigo em Inglês | MEDLINE | ID: mdl-38050987

RESUMO

Exciton-coupled chromophore dimers are an emerging class of optical probes for studies of site-specific biomolecular interactions. Applying accurate theoretical models for the electrostatic coupling of a molecular dimer probe is a key step for simulating its optical properties and analyzing spectroscopic data. In this work, we compare experimental absorbance and circular dichroism (CD) spectra of 'internally-labeled' (iCy3)2 dimer probes inserted site-specifically into DNA fork constructs to theoretical calculations of the structure and geometry of these exciton-coupled dimers. We compare transition density models of varying levels of approximation to determine conformational parameters of the (iCy3)2 dimer-labeled DNA fork constructs. By applying an atomistically detailed transition charge (TQ) model, we can distinguish between dimer conformations in which the stacking and tilt angles between planar iCy3 monomers are varied. A major strength of this approach is that the local conformations of the (iCy3)2 dimer probes that we determined can be used to infer information about the structures of the DNA framework immediately surrounding the probes at various positions within the constructs, both deep in the duplex DNA sequences and at sites at or near the DNA fork junctions where protein complexes bind to discharge their biological functions.


Assuntos
DNA , Sondas Moleculares , Ligação Proteica , Conformação de Ácido Nucleico , DNA/química , Dicroísmo Circular , Sítios de Ligação
16.
Angew Chem Int Ed Engl ; 63(6): e202311233, 2024 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-37856157

RESUMO

The viscosity and crowding of biological environment are considered vital for the correct cellular function, and alterations in these parameters are known to underly a number of pathologies including diabetes, malaria, cancer and neurodegenerative diseases, to name a few. Over the last decades, fluorescent molecular probes termed molecular rotors proved extremely useful for exploring viscosity, crowding, and underlying molecular interactions in biologically relevant settings. In this review, we will discuss the basic principles underpinning the functionality of these probes and will review advances in their use as sensors for lipid order, protein crowding and conformation, temperature and non-canonical nucleic acid structures in live cells and other relevant biological settings.


Assuntos
Corantes Fluorescentes , Sondas Moleculares , Viscosidade , Corantes Fluorescentes/química , Sondas Moleculares/química , Conformação Molecular , Proteínas
17.
Anal Chem ; 96(1): 272-280, 2024 01 09.
Artigo em Inglês | MEDLINE | ID: mdl-38131222

RESUMO

Fluorescence analysis is an increasingly important contributor to the early diagnosis of kidney diseases. To achieve precise visualization of the kidneys and early diagnosis of related diseases, an asymmetric pyrrolopyrrolidone (DPP) dye platform with C-aromatic substituents and N-lipophilic/hydrophilic modification was constructed. Based on these, we developed the renal-clearable, water-soluble, and kidney injury biomarker leucine aminopeptidase (LAP) activated ratiometric fluorescent probe DPP-S-L. In the mouse model of cisplatin-induced acute kidney injury and during the development of type 2 diabetes to diabetic kidney disease, we visualized for the first time the upregulation of LAP in the kidney and urine by dual-channel ratiometric fluorescence signal and diagnosed the kidney injury earlier and more sensitively than blood/urine enzyme detection and tissue analysis. This study showcases an excellent asymmetric DPP dye platform and renal-clearable ratiometric fluorescent probe design strategy that is extended to determination and visualization of other biomarkers for early disease diagnosis.


Assuntos
Diabetes Mellitus Tipo 2 , Sondas Moleculares , Animais , Camundongos , Corantes Fluorescentes , Leucil Aminopeptidase/análise , Biomarcadores , Rim/química , Diagnóstico Precoce , Imagem Óptica
18.
Langmuir ; 40(1): 657-667, 2024 01 09.
Artigo em Inglês | MEDLINE | ID: mdl-38100549

RESUMO

Vesicles formed by phospholipids are promising candidates for drug delivery. It is known that the lipid composition affects properties such as the rigidity-fluidity of the membrane and that it influences the bilayer permeability, but sometimes sophisticated techniques are selected to monitor them. In this work, we study the bilayer of different unilamellar vesicles composed of different lipids (1,2-dioleoyl-sn-glycero-3-phosphocholine, DOPC, and lecithin) and diverse techniques such as extruder and electrospun templates and using 6-propionyl-2-(N,N-dimethyl) aminonaphthalene (PRODAN) and its photophysics. Moreover, we were able to monitor the influence of cholesterol on the bilayers. We demonstrate that the bilayer properties can be evaluated using the emission feature of the molecular probe PRODAN. This fluorescent probe gives relevant information on the polarity and fluidity of the microenvironment for unilamellar vesicles formed by two different methods. The PRODAN emission at 434 nm suggests that the bilayer properties significantly change if DOPC or lecithin is used in the vesicle preparation especially in their fluidity. Moreover, cholesterol induces alterations in the bilayer's structural and microenvironmental properties to a greater or lesser degree in both vesicles. Thus, we propose an easy and elegant way to evaluate physicochemical properties, which is fundamental for manufacturing vesicles as a drug delivery system, simply by monitoring the molecular probe emission band centered at 434 nm, which corresponds to the PRODAN species deep inside the bilayer.


Assuntos
Fosfolipídeos , Lipossomas Unilamelares , Fosfolipídeos/química , Lipossomas Unilamelares/química , Lecitinas , Bicamadas Lipídicas/química , Sondas Moleculares , Colesterol/química , Fosfatidilcolinas/química
19.
J Am Chem Soc ; 145(51): 28296-28306, 2023 12 27.
Artigo em Inglês | MEDLINE | ID: mdl-38090812

RESUMO

Atherosclerosis (AS) is the formation of plaques in blood vessels, which leads to serious cardiovascular diseases. Current research has disclosed that the formation of AS plaques is highly related to the foaming of macrophages. However, there is a lack of detailed molecular biological mechanisms. We proposed a "live sensor" by grafting a tetrazine-based ratiometric NO probe within macrophages through metabolic and bio-orthogonal labeling. This "live sensor" was proved to target the AS plaques with a diameter of only tens of micrometers specifically and visualized endogenous NO at two lesion stages in the AS mouse model. The ratiometric signals from the probe confirmed the participation of NO during AS and indicated that the generation of endogenous NO increased significantly as the lesion progressed. Our proposal of this "live sensor" provided a native and smart strategy to target and deliver small molecular probes to the AS plaques at the in vivo level, which can be used as universal platforms for the detection of reactive molecules or microenvironmental factors in AS.


Assuntos
Aterosclerose , Placa Aterosclerótica , Camundongos , Animais , Óxido Nítrico/metabolismo , Placa Aterosclerótica/metabolismo , Placa Aterosclerótica/patologia , Macrófagos/metabolismo , Aterosclerose/metabolismo , Aterosclerose/patologia , Sondas Moleculares/metabolismo
20.
Biomolecules ; 13(12)2023 12 12.
Artigo em Inglês | MEDLINE | ID: mdl-38136647

RESUMO

Currently, there is great interest in the development of highly sensitive bioanalytical systems for diagnosing diseases at an early stage, when pathological biomarkers are present in biological fluids at low concentrations and there are no clinical manifestations. A promising direction is the use of molecular detectors-highly sensitive devices that detect signals from single biomacromolecules. A typical detector in this class is the atomic force microscope (AFM). The high sensitivity of an AFM-based bioanalysis system is determined by the size of the sensing element of an atomic force microscope-the cantilever-the radius of the curvature of which is comparable to that of a biomolecule. Biospecific molecular probe-target interactions are used to ensure detection system specificity. Antibodies, aptamers, synthetic antibodies, and peptides can be used as molecular probes. This study has demonstrated the possibility of using aptamers as molecular probes for AFM-based detection of the ovarian cancer biomarker CA125. Antigen detection in a nanomolar solution was carried out using AFM chips with immobilized aptamers, commercially available or synthesized based on sequences from open sources. Both aptamer types can be used for antigen detection, but the availability of sequence information enables additional modeling of the aptamer structure with allowance for modifications necessary for immobilization of the aptamer on an AFM chip surface. Information on the structure and oligomeric composition of aptamers in the solution was acquired by combining small-angle X-ray scattering and molecular modeling. Modeling enabled pre-selection, before the experimental stage, of aptamers for use as surface-immobilized molecular probes.


Assuntos
Aptâmeros de Nucleotídeos , Microscopia de Força Atômica , Aptâmeros de Nucleotídeos/química , Sondas Moleculares , Modelos Moleculares
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...