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1.
Curr Protein Pept Sci ; 25(6): 443-453, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38284715

RESUMEN

Lectins are proteins widely distributed among plants, animals and microorganisms that have the ability to recognize and interact with specific carbohydrates. They have varied biological activities, such as the inhibition of the progression of infections caused by fungi, bacteria, viruses and protozoa, which is related to the interaction of these proteins with the carbohydrates present in the cell walls of these microorganisms. Leishmaniasis are a group of endemic infectious diseases caused by protozoa of the genus Leishmania. In vitro and in vivo tests with promastigotes and amastigotes of Leishmania demonstrated that lectins have the ability to interact with glycoconjugates present on the cell surface of the parasite, it prevents their development through various mechanisms of action, such as the production of ROS and alteration of membrane integrity, and can also interact with defense cells present in the human body, thus showing that these molecules can be considered alternative pharmacological targets for the treatment of leishmaniasis. The objective of the present work is to carry out a bibliographic review on lectins with leishmanicidal activity, emphasizing the advances and perspectives of research in this theme. Through the analysis of the selected studies, we were able to conclude that lectins have great potential for inhibiting the development of leishmaniasis. However, there are still few studies on this subject.


Asunto(s)
Lectinas , Leishmania , Leishmaniasis , Leishmania/efectos de los fármacos , Humanos , Lectinas/farmacología , Lectinas/química , Lectinas/metabolismo , Leishmaniasis/tratamiento farmacológico , Leishmaniasis/parasitología , Animales , Antiprotozoarios/farmacología , Antiprotozoarios/química , Especies Reactivas de Oxígeno/metabolismo
2.
ACS Nano ; 18(4): 3023-3042, 2024 Jan 30.
Artículo en Inglés | MEDLINE | ID: mdl-38241477

RESUMEN

Antibiotic resistance is a pressing public health threat. Despite rising resistance, antibiotic development, especially for Gram-negative bacteria, has stagnated. As the traditional antibiotic research and development pipeline struggles to address this growing concern, alternative solutions become imperative. Synthetic molecular nanomachines (MNMs) are molecular structures that rotate unidirectionally in a controlled manner in response to a stimulus, such as light, resulting in a mechanical action that can propel molecules to drill into cell membranes, causing rapid cell death. Due to their broad destructive capabilities, clinical translation of MNMs remains challenging. Hence, here, we explore the ability of nonlethal visible-light-activated MNMs to potentiate conventional antibiotics against Gram-negative bacteria. Nonlethal MNMs enhanced the antibacterial activity of various classes of conventional antibiotics against Gram-negative bacteria, including those typically effective only against Gram-positive strains, reducing the antibiotic concentration required for bactericidal action. Our study also revealed that MNMs bind to the negatively charged phospholipids of the bacterial inner membrane, leading to permeabilization of the cell envelope and impairment of efflux pump activity following light activation of MNMs. The combined effects of MNMs on membrane permeability and efflux pumps resulted in increased antibiotic accumulation inside the cell, reversing antibiotic resistance and attenuating its development. These results identify nonlethal MNMs as pleiotropic antibiotic enhancers or adjuvants. The combination of MNMs with traditional antibiotics is a promising strategy against multidrug-resistant Gram-negative infections. This approach can reduce the amount of antibiotics needed and slow down antibiotic resistance development, thereby preserving the effectiveness of our current antibiotics.


Asunto(s)
Antibacterianos , Farmacorresistencia Bacteriana Múltiple , Antibacterianos/metabolismo , Bacterias Gramnegativas , Transporte Biológico , Permeabilidad
3.
Adv Mater ; 36(7): e2306669, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-38062893

RESUMEN

Molecular motors (MM) are molecular machines, or nanomachines, that rotate unidirectionally upon photostimulation and perform mechanical work on their environment. In the last several years, it has been shown that the photomechanical action of MM can be used to permeabilize lipid bilayers, thereby killing cancer cells and pathogenic microorganisms and controlling cell signaling. The work contributes to a growing acknowledgement that the molecular actuation characteristic of these systems is useful for various applications in biology. However, the mechanical effects of molecular motion on biological materials are difficult to disentangle from photodynamic and photothermal action, which are also present when a light-absorbing fluorophore is irradiated with light. Here, an overview of the key methods used by various research groups to distinguish the effects of photomechanical, photodynamic, and photothermal action is provided. It is anticipated that this discussion will be helpful to the community seeking to use MM to develop new and distinctive medical technologies that result from mechanical disruption of biological materials.


Asunto(s)
Membrana Dobles de Lípidos , Fotoquimioterapia , Movimiento (Física)
4.
Curr Protein Pept Sci ; 25(2): 172-182, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-37694793

RESUMEN

INTRODUCTION: Trypsin inhibitors (TIs) have the ability to competitively or non-competitively bind to trypsin and inhibit its action. These inhibitors are commonly found in plants and are used in protease inhibition studies involved in biochemical pathways of pharmacological interest. OBJECTIVES: This work aimed to purify a trypsin inhibitor from Bauhinia pulchella seeds (BpuTI), describing its kinetic mechanism and anticoagulant effect. METHODS: Affinity chromatography, protein assay, and SDS-PAGE were used to purify the inhibitor. Mass spectrometry, inhibition assays, and enzyme kinetics were used to characterize the inhibitor. In vitro assays were performed to verify its ability to prolong blood clotting time. RESULTS: Affinity chromatography on a Trypsin-Sepharose 4B column gave a yield of 43.1. BpuTI has an apparent molecular mass of 20 kDa with glycosylation (1.15%). Protein identification was determined by MS/MS, and BpuTI showed similarity to several Kunitz-type trypsin inhibitors. BpuTI inhibited bovine trypsin as an uncompetitive inhibitor with IC50 (3 x 10-6 M) and Ki (1.05 x 10-6 M). Additionally, BpuTI showed high stability to temperature and pH variations, maintaining its activity up to 100ºC and in extreme pH ranges. However, the inhibitor was susceptible to reducing agents, such as DTT, which completely abolished its activity. BpuTI showed an anticoagulant effect in vitro at a concentration of 33 µM, prolonging clotting time by 2.6 times. CONCLUSION: Our results suggest that BpuTI can be a biological tool to be used in blood clotting studies.


Asunto(s)
Bauhinia , Inhibidores de Tripsina , Animales , Bovinos , Inhibidores de Tripsina/farmacología , Inhibidores de Tripsina/química , Bauhinia/metabolismo , Tripsina/análisis , Tripsina/química , Tripsina/metabolismo , Espectrometría de Masas en Tándem , Semillas/química , Anticoagulantes/farmacología , Anticoagulantes/análisis , Anticoagulantes/química
5.
Nat Commun ; 14(1): 7475, 2023 11 17.
Artículo en Inglés | MEDLINE | ID: mdl-37978172

RESUMEN

Non-natural amino acids are increasingly used as building blocks in the development of peptide-based drugs as they expand the available chemical space to tailor function, half-life and other key properties. However, while the chemical space of modified amino acids (mAAs) such as residues containing post-translational modifications (PTMs) is potentially vast, experimental methods for measuring the developability properties of mAA-containing peptides are expensive and time consuming. To facilitate developability programs through computational methods, we present CamSol-PTM, a method that enables the fast and reliable sequence-based prediction of the intrinsic solubility of mAA-containing peptides in aqueous solution at room temperature. From a computational screening of 50,000 mAA-containing variants of three peptides, we selected five different small-size mAAs for a total number of 37 peptide variants for experimental validation. We demonstrate the accuracy of the predictions by comparing the calculated and experimental solubility values. Our results indicate that the computational screening of mAA-containing peptides can extend by over four orders of magnitude the ability to explore the solubility chemical space of peptides and confirm that our method can accurately assess the solubility of peptides containing mAAs. This method is available as a web server at https://www-cohsoftware.ch.cam.ac.uk/index.php/camsolptm .


Asunto(s)
Aminoácidos , Péptidos , Solubilidad , Péptidos/química
6.
Biochim Biophys Acta Gen Subj ; 1867(12): 130474, 2023 12.
Artículo en Inglés | MEDLINE | ID: mdl-37778449

RESUMEN

The differential energy metabolism of cancer cells has stimulated the development of tools that can be applied to better understand the complex biological interaction involved in the uptake of glucose analogs at the cellular level in this disease. Herein, we explored the outstanding optical properties of quantum dots (QDs) to develop a new fluorescent glyconanoprobe using the 1-thio-ß-d-glucose (Glc). Then, monolayers and spheroids of HeLa cells were applied to probe the biological interaction with the conjugate through fluorescence techniques. Spheroids have been gaining prominence for better mimicking the tumor microenvironment. The Glc-QDs conjugate was prepared by a facile and direct procedure based on the affinity of the Glc thiol group by the QD semiconductor surface. The conjugation was evaluated and confirmed by Zeta potential (ζ) measurements, FTIR spectroscopy, and fluorescence correlation spectroscopy (FCS). Moreover, a biological assay using Candida albicans yeasts coated with concanavalin A, by exploring the lectin-carbohydrate affinity, was also developed to further confirm the conjugation, which corroborated the previous analyses. The hanging drop method was used to prepare the spheroids. The fluorescence microscopy analyses indicated an intracellular labeling by the glyconanoprobe, in both cell culture models. Flow cytometry assays revealed effective uptake of the conjugate (above ca. 76%), even by cells cultivated as spheroids, applying short incubation time. Therefore, a new fluorescent glyconanoprobe was developed, which showed potential to be applied for investigating mechanisms involved in the uptake of glucose analogs, both by simpler and complex cancer biological models, as monolayers and spheroids.


Asunto(s)
Neoplasias , Puntos Cuánticos , Humanos , Puntos Cuánticos/química , Células HeLa , Glucosa/metabolismo , Candida albicans/metabolismo , Colorantes Fluorescentes/química
7.
Front Endocrinol (Lausanne) ; 14: 1217021, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37554763

RESUMEN

Introduction: Oxyntomodulin (Oxm) hormone peptide has a number of beneficial effects on nutrition and metabolism including increased energy expenditure and reduced body weight gain. Despite its many advantages as a potential therapeutic agent, Oxm is subjected to rapid renal clearance and protease degradation limiting its clinical application. Previously, we have shown that subcutaneous administration of a fibrillar Oxm formulation can significantly prolong its bioactivity in vivo from a few hours to a few days. Methods: We used a protease resistant analogue of Oxm, Aib2-Oxm, to form nanfibrils depot and improve serum stability of released peptide. The nanofibrils and monomeric peptide in solution were characterized by spectroscopic, microscopic techniques, potency assay, QCM-D and in vivo studies. Results: We show that in comparison to Oxm, Aib2-Oxm fibrils display a slower elongation rate requiring higher ionic strength solutions, and a higher propensity to dissociate. Upon subcutaneous administration of fibrillar Aib2-Oxm in rodents, a 5-fold increase in bioactivity relative to fibrillar Oxm and a significantly longer bioactivity than free Aib2-Oxm were characterized. Importantly, a decrease in food intake was observed up to 72-hour post-administration, which was not seen for free Aib2-Oxm. Conclusion: Our findings provides compelling evidence for the development of long-lasting peptide fibrillar formulations that yield extended plasma exposure and enhanced in vivo pharmacological response.


Asunto(s)
Péptido 1 Similar al Glucagón , Glucagón , Ingestión de Alimentos/fisiología , Glucagón/metabolismo , Péptido 1 Similar al Glucagón/farmacología , Oxintomodulina/química , Oxintomodulina/farmacología , Péptido Hidrolasas , Péptidos/farmacología , Receptores de Glucagón/metabolismo , Animales
8.
Nat Nanotechnol ; 18(9): 1051-1059, 2023 09.
Artículo en Inglés | MEDLINE | ID: mdl-37430037

RESUMEN

Intercellular calcium waves (ICW) are complex signalling phenomena that control many essential biological activities, including smooth muscle contraction, vesicle secretion, gene expression and changes in neuronal excitability. Accordingly, the remote stimulation of ICW could result in versatile biomodulation and therapeutic strategies. Here we demonstrate that light-activated molecular machines (MM)-molecules that perform mechanical work on the molecular scale-can remotely stimulate ICW. MM consist of a polycyclic rotor and stator that rotate around a central alkene when activated with visible light. Live-cell calcium-tracking and pharmacological experiments reveal that MM-induced ICW are driven by the activation of inositol-triphosphate-mediated signalling pathways by unidirectional, fast-rotating MM. Our data suggest that MM-induced ICW can control muscle contraction in vitro in cardiomyocytes and animal behaviour in vivo in Hydra vulgaris. This work demonstrates a strategy for directly controlling cell signalling and downstream biological function using molecular-scale devices.


Asunto(s)
Señalización del Calcio , Uniones Comunicantes , Animales , Señalización del Calcio/genética , Uniones Comunicantes/metabolismo , Contracción Muscular , Fosfatos de Inositol/metabolismo , Calcio/metabolismo
9.
Chem Biol Interact ; 382: 110639, 2023 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-37468117

RESUMEN

Lectins are proteins of non-immunological origin with the ability to bind to carbohydrates reversibly. They emerge as an alternative to conventional antifungals, given the ability to interact with carbohydrates in the fungal cell wall inhibiting fungal growth. The lectin from D. violacea (DVL) already has its activity described as anti-candida in some species. Here, we observed the anti-candida effect of DVL on C. albicans, C. krusei and C. parapsilosis and its multiple mechanisms of action toward the yeasts. Additionally, it was observed that DVL induces membrane and cell wall damage and ROS overproduction. DVL was also able to cause an imbalance in the redox system of the cells, interact with ergosterol, inhibit ergosterol biosynthesis, and induce cytochrome c release from the mitochondrial membrane. These results endorse the potential application of DVL in developing a new antifungal drug to fight back against fungal resistance.


Asunto(s)
Dioclea , Lectinas , Lectinas/farmacología , Candida/metabolismo , Dioclea/metabolismo , Lectinas de Plantas/farmacología , Lectinas de Plantas/metabolismo , Antifúngicos/farmacología , Carbohidratos , Semillas/metabolismo , Ergosterol , Candida albicans , Pruebas de Sensibilidad Microbiana
10.
Nat Commun ; 14(1): 2209, 2023 04 18.
Artículo en Inglés | MEDLINE | ID: mdl-37072447

RESUMEN

Genetically identical cells in the same stressful condition die at different times. The origin of this stochasticity is unclear; it may arise from different initial conditions that affect the time of demise, or from a stochastic damage accumulation mechanism that erases the initial conditions and instead amplifies noise to generate different lifespans. To address this requires measuring damage dynamics in individual cells over the lifespan, but this has rarely been achieved. Here, we used a microfluidic device to measure membrane damage in 635 carbon-starved Escherichia coli cells at high temporal resolution. We find that initial conditions of damage, size or cell-cycle phase do not explain most of the lifespan variation. Instead, the data points to a stochastic mechanism in which noise is amplified by a rising production of damage that saturates its own removal. Surprisingly, the relative variation in damage drops with age: cells become more similar to each other in terms of relative damage, indicating increasing determinism with age. Thus, chance erases initial conditions and then gives way to increasingly deterministic dynamics that dominate the lifespan distribution.


Asunto(s)
Escherichia coli , Escherichia coli/metabolismo , División Celular , Muerte Celular , Procesos Estocásticos
11.
Subcell Biochem ; 103: 341-435, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37120475

RESUMEN

The gradual ageing of the world population has been accompanied by a dramatic increase in the prevalence of obesity and metabolic diseases, especially type 2 diabetes. The adipose tissue dysfunction associated with ageing and obesity shares many common physiological features, including increased oxidative stress and inflammation. Understanding the mechanisms responsible for adipose tissue dysfunction in obesity may help elucidate the processes that contribute to the metabolic disturbances that occur with ageing. This, in turn, may help identify therapeutic targets for the treatment of obesity and age-related metabolic disorders. Because oxidative stress plays a critical role in these pathological processes, antioxidant dietary interventions could be of therapeutic value for the prevention and/or treatment of age-related diseases and obesity and their complications. In this chapter, we review the molecular and cellular mechanisms by which obesity predisposes individuals to accelerated ageing. Additionally, we critically review the potential of antioxidant dietary interventions to counteract obesity and ageing.


Asunto(s)
Antioxidantes , Diabetes Mellitus Tipo 2 , Humanos , Antioxidantes/uso terapéutico , Antioxidantes/metabolismo , Envejecimiento/patología , Estrés Oxidativo , Obesidad/tratamiento farmacológico
12.
Arch Clin Neuropsychol ; 38(3): 408-432, 2023 Apr 26.
Artículo en Inglés | MEDLINE | ID: mdl-36988491

RESUMEN

OBJECTIVE: The Latina(o)/Hispanic (L/H) population represents the largest and fastest-growing ethnic group in the United States. Migration patterns have evolved and greater diversity (i.e., country of origin) is evident, highlighting the ever-changing heterogeneity of this community and the need for the field of neuropsychology to ensure equitable care for linguistically and culturally diverse communities. This paper aims to provide a flexible protocol of neuropsychological instruments appropriate for primarily Spanish-speaking adults residing in the United States. METHOD: Spanish measures were selected based on availability, translations/cultural modifications, accompanying normative data sets, and clinician experience/acumen. Bilingual/bicultural providers of neuropsychological services to Spanish speakers across the training spectrum working at U.S.-based medical centers implemented a multimodal approach (i.e., literature search, clinical practice parameters, and focus groups) in the development of a multi-domain primary protocol that includes core and supplemental measures that are appropriate for individuals with varying linguistic proficiency and sociocultural demographic characteristics. RESULTS: A multi-domain, evidence-based, flexible neuropsychological protocol is presented. Recommendations for test selection based on sociocultural demographic factors and examples of clinical assessment practices are provided via a case illustration. Most instruments included may be applied across cultural and regional backgrounds. CONCLUSION: Provision of neuropsychological services to primarily Spanish-speaking adults presents unique challenges. Existing Spanish measures and accompanying data rarely capture the heterogeneity of L/H individuals. Although Spanish has the largest number of neurocognitive instruments, relative to other languages, robust and representative norms continue to be scarce. Future studies should prioritize collecting normative data from educationally and geographically diverse samples.


Asunto(s)
Hispánicos o Latinos , Lenguaje , Adulto , Humanos , Estados Unidos , Pruebas Neuropsicológicas , Hispánicos o Latinos/psicología , Etnicidad , Traducciones
13.
Arch Clin Neuropsychol ; 38(3): 501-512, 2023 Apr 26.
Artículo en Inglés | MEDLINE | ID: mdl-36988624

RESUMEN

OBJECTIVE: As the third largest immigrant population in Houston, Texas, Brazilians represent a large bloc of the community in need of culturally and linguistically informed healthcare. In particular, the number of older adults within this population is rapidly growing, emphasizing the increased need to develop socially responsible neuropsychological assessment practices that can meet the needs of this demographic. Additionally, early symptoms of cognitive decline in Brazilian older adults can be culturally perceived as normal aging and may be masked by cultural and lifestyle practices (i.e., scaffolding by family members) that result in lack of appreciation for cognitive and functional decrements. With increased knowledge and awareness of Brazilian culture and customs, we can better understand and assess brain-behavior relationships, provide tailored assessment services, and determine the clinical implications for this population. METHODS: Test instruments in Portuguese were identified through systematic literature searches, and in consultation with clinicians serving the Portuguese community in the United States, and cultural brokers involved in Brazilian-based neuropsychology. RESULTS: A multidomain neuropsychological battery with accompanying normative data for use with adults from this community is presented. A case illustration is utilized to highlight limitations and strengths of the proposed battery, which includes core and supplemental measures. CONCLUSION: Neuropsychologists are encouraged to familiarize themselves with the proposed protocol, understand the psychometric limitations of the available tools, and make an earnest attempt toward providing socially responsible neuropsychological care via the appropriate use of culturally and linguistically tailored instruments and clinical practices.


Asunto(s)
Competencia Cultural , Lenguaje , Anciano , Humanos , Brasil , Pruebas Neuropsicológicas , Estados Unidos
14.
Int J Biol Macromol ; 236: 123941, 2023 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-36893486

RESUMEN

DVL is a Man/Glc-binding lectin from Dioclea violacea seeds that has the ability to interact with the antibiotic gentamicin. The present work aimed to evaluate whether the DVL has the ability to interact with neomycin via CRD and to examine the ability of this lectin to modulate the antibiotic effect of neomycin against multidrug-resistant strains (MDR). The hemagglutinating activity test revealed that neomycin inhibited the hemagglutinating activity of DVL with a minimum inhibitory concentration of 50 mM, indicating that the antibiotic interacts with DVL via the carbohydrate recognition domain (CRD). DVL immobilized on cyanogen bromide-activated Sepharose® 4B bound 41 % of the total neomycin applied to the column, indicating that the DVL-neomycin interaction is efficient for purification processes. Furthermore, the minimum inhibitory concentrations (MIC) obtained for DVL against all strains studied were not clinically relevant. However, when DVL was combined with neomycin, a significant increase in antibiotic activity was observed against S. aureus and P. aeruginosa. These results demonstrate the first report of lectin-neomycin interaction, indicating that immobilized DVL has the potential to isolate neomycin by affinity chromatography. Moreover, DVL increased the antibiotic activity of neomycin against MDR, suggesting that it is a potent adjuvant in the treatment of infectious diseases.


Asunto(s)
Dioclea , Fabaceae , Humanos , Masculino , Lectinas/farmacología , Antibacterianos/farmacología , Dioclea/química , Neomicina/farmacología , Lectinas de Plantas/química , Staphylococcus aureus/metabolismo , Fabaceae/metabolismo
15.
Adv Sci (Weinh) ; 10(10): e2205781, 2023 04.
Artículo en Inglés | MEDLINE | ID: mdl-36715588

RESUMEN

Invasive fungal infections are a growing public health threat. As fungi become increasingly resistant to existing drugs, new antifungals are urgently needed. Here, it is reported that 405-nm-visible-light-activated synthetic molecular machines (MMs) eliminate planktonic and biofilm fungal populations more effectively than conventional antifungals without resistance development. Mechanism-of-action studies show that MMs bind to fungal mitochondrial phospholipids. Upon visible light activation, rapid unidirectional drilling of MMs at ≈3 million cycles per second (MHz) results in mitochondrial dysfunction, calcium overload, and ultimately necrosis. Besides their direct antifungal effect, MMs synergize with conventional antifungals by impairing the activity of energy-dependent efflux pumps. Finally, MMs potentiate standard antifungals both in vivo and in an ex vivo porcine model of onychomycosis, reducing the fungal burden associated with infection.


Asunto(s)
Antifúngicos , Calcio , Animales , Porcinos , Antifúngicos/farmacología , Antifúngicos/uso terapéutico , Antifúngicos/metabolismo , Calcio/metabolismo , Hongos/metabolismo
16.
Adv Sci (Weinh) ; 9(30): e2203242, 2022 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-36002317

RESUMEN

Antibiotic resistance is a growing health threat. There is an urgent and critical need to develop new antimicrobial modalities and therapies. Here, a set of hemithioindigo (HTI)-based molecular machines capable of specifically killing Gram-positive bacteria within minutes of activation with visible light (455 nm at 65 mW cm-2 ) that are safe for mammalian cells is described. Importantly, repeated exposure of bacteria to HTI does not result in detectable development of resistance. Visible light-activated HTI kill both exponentially growing bacterial cells and antibiotic-tolerant persister cells of various Gram-positive strains, including methicillin-resistant S. aureus (MRSA). Visible light-activated HTI also eliminate biofilms of S. aureus and B. subtilis in as little as 1 h after light activation. Quantification of reactive oxygen species (ROS) formation and protein carbonyls, as well as assays with various ROS scavengers, identifies oxidative damage as the underlying mechanism for the antibacterial activity of HTI. In addition to their direct antibacterial properties, HTI synergize with conventional antibiotics in vitro and in vivo, reducing the bacterial load and mortality associated with MRSA infection in an invertebrate burn wound model. To the best of the authors' knowledge, this is the first report on the antimicrobial activity of HTI-based molecular machines.


Asunto(s)
Staphylococcus aureus Resistente a Meticilina , Animales , Pruebas de Sensibilidad Microbiana , Staphylococcus aureus/metabolismo , Especies Reactivas de Oxígeno/metabolismo , Antibacterianos/farmacología , Antibacterianos/uso terapéutico , Bacterias , Luz , Estrés Oxidativo , Mamíferos/metabolismo
17.
Sci Adv ; 8(22): eabm2055, 2022 Jun 03.
Artículo en Inglés | MEDLINE | ID: mdl-35648847

RESUMEN

The increasing occurrence of antibiotic-resistant bacteria and the dwindling antibiotic research and development pipeline have created a pressing global health crisis. Here, we report the discovery of a distinctive antibacterial therapy that uses visible (405 nanometers) light-activated synthetic molecular machines (MMs) to kill Gram-negative and Gram-positive bacteria, including methicillin-resistant Staphylococcus aureus, in minutes, vastly outpacing conventional antibiotics. MMs also rapidly eliminate persister cells and established bacterial biofilms. The antibacterial mode of action of MMs involves physical disruption of the membrane. In addition, by permeabilizing the membrane, MMs at sublethal doses potentiate the action of conventional antibiotics. Repeated exposure to antibacterial MMs is not accompanied by resistance development. Finally, therapeutic doses of MMs mitigate mortality associated with bacterial infection in an in vivo model of burn wound infection. Visible light-activated MMs represent an unconventional antibacterial mode of action by mechanical disruption at the molecular scale, not existent in nature and to which resistance development is unlikely.

18.
J Funct Biomater ; 13(2)2022 Apr 18.
Artículo en Inglés | MEDLINE | ID: mdl-35466227

RESUMEN

The quest for an ideal biomaterial perfectly matching the microenvironment of the surrounding tissues and cells is an endless challenge within biomedical research, in addition to integrating this with a facile and sustainable technology for its preparation. Engineering hydrogels through click chemistry would promote the sustainable invention of tailor-made hydrogels. Herein, we disclose a versatile and facile catalyst-free click chemistry for the generation of an innovative hydrogel by combining chondroitin sulfate (CS) and polyethylene glycol (PEG). Various multi-armed PEG-Norbornene (A-PEG-N) with different molecular sizes were investigated to generate crosslinked copolymers with tunable rheological and mechanical properties. The crosslinked and mechanically stable porous hydrogels could be generated by simply mixing the two clickable Tetrazine-CS (TCS) and A-PEG-N components, generating a self-standing hydrogel within minutes. The leading candidate (TCS-8A-PEG-N (40 kD)), based on the mechanical and biocompatibility results, was further employed as a scaffold to improve wound closure and blood flow in vivo. The hydrogel demonstrated not only enhanced blood perfusion and an increased number of blood vessels, but also desirable fibrous matrix orientation and normal collagen deposition. Taken together, these results demonstrate the potential of the hydrogel to improve wound repair and hold promise for in situ skin tissue engineering applications.

19.
Dig Dis ; 40(6): 835-838, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35081538

RESUMEN

A 48-year-old woman was admitted in the emergency department due to epigastric pain, nausea, vomiting, and cough. She presented with fever and increased inflammatory parameters. A thoracoabdominal computed tomography (CT) was performed and revealed thickening of the gastric fundus and esophagus, with an apparent laceration in esophageal mucosa and associated dissection of esophageal wall. In upper endoscopy (UE), a bulging of esophageal and gastric walls was observed, with an ulceration in proximal esophagus, suggestive of a perforation. After multidisciplinary discussion, a minimally invasive endoscopic approach was decided. Internal esophageal drainage (IED) was assured with performance of some incisions with Dual-knife® (Olympus, Tokyo) along the mucosal and submucosal layers in the esophagus. During the incision, extravasation of pus was evident. One week later, due to clinical worsening and evidence of esophageal perforation in CT scan, UE was repeated. We confirmed esophageal perforation with visualization of two millimetric defects in the proximal esophagus. Significant bulging of the gastric fundus and body was also observed. IED was repeated with mucosal incision of the gastric bulging using Needle-Cut 3V® (Olympus, Tokyo), with extravasation of a significant quantity of pus. We decided to proceed to endoscopic vacuum therapy that was performed with sponge placement in the esophageal lumen (Endosponge®, B. Braun, Melsungen, Germany). UE was repeated 1 week later with sponge removal and confirmation of resolution of esophageal perforation. An improvement of the thickening of gastric fundus and body was also seen. One month later after admission, the patient was discharged home, eating normally, and remains well in the follow-up.


Asunto(s)
Perforación del Esófago , Esofagitis , Femenino , Humanos , Persona de Mediana Edad , Perforación del Esófago/cirugía , Gastroscopía , Supuración
20.
Chem Biol Interact ; 351: 109714, 2022 Jan 05.
Artículo en Inglés | MEDLINE | ID: mdl-34710376

RESUMEN

The use of schiff base complex against microbial agentes a has recently received more attention as a strategy to combat infections caused by multidrug-resistant bacteria and leishmania. This study aimed to evaluate the toxicity, antibacterial and leishmanicidal activities of the nickel (II) chloride schiff base complex ([Ni(L2)] against Leishmania amazonensis promastigote, multi-resistant bacterial strains and evaluate to modulate antibiotic activity against multi-resistant bacterial. The schiff base complex was characterized by the techniques of elemental analysis, Fourier transform infrared spectroscopy (FTIR), UV-vis absorption spectroscopy and thermal analysis (TGA/DTG/DSC). The [Ni(L2)] complex presented moderate toxicity in saline artemia (LC50 = 150.8 µg/mL). In leishmanicidal assay, the NiL2 complex showed values of IC50 of (6.079 µg/mL ± 0.05656 at the 24 h), (0.854 µg/mL ± 0.02474, 48 h) and (1.076 µg/mL ± 0.04039, 72 h). In antibacterial assay, the [Ni(L2)] complex presented significant inhibited the bacterial growth of P. aeruginosa (MIC = 256 µg/mL). However, [Ni(L2)] complex did not present clinically relevant minimum inhibitory concentration (MIC ≥1024 µg/mL) against S. aureus and E. coli. The combination of [Ni(L2)] complex and antibacterial drugs resulted in the increased antibiotic activity of gentamicin and amikacin against S. aureus and E.coli multi-resistant strains. Thus, our results showed that [Ni(L2)] complex is a promising molecule for the development of new therapies associated with aminoglycoside antibiotics and in disease control related to resistant bacteria and leishmaniasis.


Asunto(s)
Antibacterianos/farmacología , Complejos de Coordinación/farmacología , Bases de Schiff/farmacología , Tripanocidas/farmacología , Amicacina/farmacología , Animales , Antibacterianos/química , Artemia/efectos de los fármacos , Complejos de Coordinación/química , Sinergismo Farmacológico , Escherichia coli/efectos de los fármacos , Gentamicinas/farmacología , Leishmania infantum/efectos de los fármacos , Pruebas de Sensibilidad Microbiana , Níquel/química , Pruebas de Sensibilidad Parasitaria , Pseudomonas aeruginosa/efectos de los fármacos , Bases de Schiff/química , Staphylococcus aureus/efectos de los fármacos , Tripanocidas/química
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