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1.
Angew Chem Int Ed Engl ; : e202414239, 2024 Aug 22.
Artículo en Inglés | MEDLINE | ID: mdl-39171779

RESUMEN

With growing threats from counterfeiting-based security breaches, multi-level and specific stimuli-responsive anti-counterfeiting devices and message encryption methods have attracted immense research interest. Fluorescence-based encryption from aggregation-induced emission (AIE)-based materials solves the problems to a considerable extent. However, the development of smarter patterns with hierarchical security levels alongside dynamic display is still challenging. To screen out this complication, we bring forward a pH-switchable fluorescent assembly of an AIEgen and an aliphatic acid. We later temporally direct the molecular assembly with the aid of a chemical trigger-regulated pH clock, generating a transitory multicolor emission, including transient white light generation. The pH-dependent emissions were further implemented in constructing smart multi-input fluorescent chemical AND gates. Subsequently, we integrate the time-gated emissive system to develop an advanced multi-dimensionally secure data encryption strategy. This novel approach enhances anti-counterfeiting measures by introducing an additional layer of security based on temporal characteristics.

2.
J Rheumatol ; 2024 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-38749560

RESUMEN

Giant cell arteritis (GCA) is the most common autoimmune systemic vasculitis of older adults.1 Typically, it affects individuals 50 years and older, and more women than men. The lifetime risk of GCA for women is 1% and 0.5% for men.

3.
Blood Cancer J ; 14(1): 86, 2024 May 28.
Artículo en Inglés | MEDLINE | ID: mdl-38806475

RESUMEN

Multiple myeloma (MM) therapeutics have evolved tremendously in recent years, with significant improvement in patient outcomes. As newer treatment options are developed, stem cell transplant (SCT) remains an important modality that provides excellent disease control and delays the progression of disease. Over the years, SCT use has increased overall in the U.S., but two distinct gaps remain, including suboptimal use overall and racial-ethnic disparities. We evaluated the National Cancer Database (NCDB) to study what sociodemographic factors might play a role within a given racial-ethnic group leading to disparate SCT utilization, such that targeted approaches can be developed to optimize SCT use for all. In nearly 112,000 cases belonging to mutually exclusive categories of non-Hispanic Whites (NHW), non-Hispanic Blacks (NHB), Hispanics, non-Hispanic Asians (NHA), and others, we found certain factors including age, comorbidity index, payor type, facility type (academic vs. community) and facility volume to be uniformly associated with SCT use for all the racial-ethnic groups, while gender was not significant for any of the groups. There were several other factors that had a differential impact on SCT utilization among the various race-ethnicity groups studied, including year of diagnosis (significant for NHW, NHB, and Hispanics), income level (significant for NHW and Hispanics), literacy level (significant for NHW and NHB), and geographic location of the treatment facility (significant for NHW and NHA). The suboptimal SCT utilization overall in the U.S. suggests that there may be room for improvement for all, even including the majority NHW, while we continue to work on factors that lead to disparities for the traditionally underserved populations. This study helps identify sociodemographic factors that may play a role specifically in each group and paves the way to devise targeted solutions such that resource utilization and impact can be maximized.


Asunto(s)
Disparidades en Atención de Salud , Mieloma Múltiple , Humanos , Mieloma Múltiple/terapia , Mieloma Múltiple/epidemiología , Masculino , Femenino , Persona de Mediana Edad , Anciano , Estados Unidos/epidemiología , Adulto , Trasplante de Células Madre , Trasplante de Células Madre Hematopoyéticas
4.
PLoS One ; 19(4): e0301296, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38574046

RESUMEN

In this study, the complex interactions between soil types, compaction, and moisture on nitrogen (N) transformation processes such as ammonia (NH3) volatilization, ammonification, nitrification, and denitrification were examined over a 30-day period using a simulated column approach. Two soil types: loam, and sandy loam, were subjected to three compaction treatments-control, surface, and sub-surface compaction-and two moisture regimes, dry and wet. Liquid urea ammonium nitrate (32-0-0) was used as the N fertilizer source at a rate of 200 kg N ha-1. Key indicators of N transformations were measured, including residual concentrations of ammonium (NH4-N) and nitrate (NO3-N), NO3-N leaching, NH3 volatilization, and nitrous oxide (N2O) emissions. Findings revealed that compaction significantly increased residual NH4-N concentrations in deeper soil profiles, with the highest 190.80 mg kg-1 recorded in loam soil under sub-surface compaction and dry conditions. Nitrification rates decreased across both soil types due to compaction, evidenced by elevated residual NH4-N levels. Increased NO3-N leaching was observed in loam soil (178.06 mg L-1), greater than sandy loam (81.11 mg L-1), due to initial higher residual NO3- in loam soil. The interaction of compaction and moisture most affected N2O emissions, with the highest emissions in control treatments during dry weather at 2.88 kg ha -1. Additionally, higher NH3 volatilization was noted in moist sandy loam soil under control conditions at 19.64 kg ha -1. These results highlight the necessity of considering soil texture, moisture, and compaction in implementing sustainable N management strategies in agriculture and suggest recommendations such as avoiding broadcast application in moist sandy loam and loam soil to mitigate NH3 volatilization and enhance N use efficiency, as well as advocating for readjustment of fertilizer rate based on organic matter content to reduce potential NO3-N leaching and N2O emissions, particularly in loam soil.


Asunto(s)
Nitrógeno , Suelo , Fertilizantes/análisis , Agricultura , Amoníaco/análisis , Arena , Óxido Nitroso/análisis
5.
Br J Haematol ; 204(5): 1825-1829, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38286472

RESUMEN

This phase II study evaluated time-limited (24 cycles) treatment with ibrutinib and ixazomib in newly diagnosed (NDWM; n = 9) and relapsed/refractory (RRWM; n = 12) Waldenström macroglobulinaemia (WM). The overall response rate (ORR) was 76.2% (n = 16) in 21 evaluable patients with no patient achieving a complete response (CR). The median duration of treatment was 15.6 months, and after a median follow-up time of 25.7 months, the median progression-free survival (PFS) was 22.9 months. While the primary end-point was not met (CR rate at any time) and 28.5% discontinued treatment due to toxicity, ibrutinib plus ixazomib led to a clinically meaningful ORR and PFS. Combined Bruton's tyrosine kinase (BTK) and proteasome inhibition merits further evaluation in WM.


Asunto(s)
Adenina , Protocolos de Quimioterapia Combinada Antineoplásica , Compuestos de Boro , Glicina , Piperidinas , Macroglobulinemia de Waldenström , Humanos , Compuestos de Boro/uso terapéutico , Compuestos de Boro/administración & dosificación , Compuestos de Boro/efectos adversos , Macroglobulinemia de Waldenström/tratamiento farmacológico , Glicina/análogos & derivados , Glicina/administración & dosificación , Glicina/efectos adversos , Glicina/uso terapéutico , Adenina/análogos & derivados , Masculino , Anciano , Persona de Mediana Edad , Femenino , Piperidinas/uso terapéutico , Piperidinas/administración & dosificación , Piperidinas/efectos adversos , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Protocolos de Quimioterapia Combinada Antineoplásica/efectos adversos , Protocolos de Quimioterapia Combinada Antineoplásica/administración & dosificación , Anciano de 80 o más Años , Pirimidinas/efectos adversos , Pirimidinas/uso terapéutico , Pirimidinas/administración & dosificación , Pirazoles/uso terapéutico , Pirazoles/efectos adversos , Pirazoles/administración & dosificación , Adulto , Resultado del Tratamiento
7.
Access Microbiol ; 5(11)2023.
Artículo en Inglés | MEDLINE | ID: mdl-38074104

RESUMEN

Background: The rapid and accurate diagnosis of tubercular lymphadenitis remains a challenging task today. The World Health Organization (WHO) endorsed the LoopAMP MTBC kit (TB-LAMP) as a replacement for sputum smear microscopy in the diagnosis of pulmonary tuberculosis (PTB). However, no prospective diagnostic accuracy study of TB-LAMP for tubercular lymphadenitis in adults has been performed yet. The current study evaluated the diagnostic performance of TB-LAMP in tubercular lymphadenitis (LNTB). Methods: In a prospective observational study conducted at a tertiary care hospital in India, 90 subjects (age >18 years) suspected of LNTB were recruited consecutively and followed up for 6 months between January 2019 and December 2020. Samples were processed for microscopy, culture, GeneXpert, histopathology and TB-LAMP. The sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of TB-LAMP against the composite reference standard (CRS) and culture were determined. Results: TB-LAMP showed a sensitivity of 83.78 % (95 % CI, 73.76-90.47) and a specificity of 81.25 % (95 % CI, 56.99-93.41), respectively, against the CRS. The PPV and NPV were 95.38 % (95 % CI, 87.29-98.42) and 52.00 % (95 % CI, 33.50-69.97), respectively. TB-LAMP showed a sensitivity of 88.89 % (95 % CI, 71.94-96.15) and a specificity of 36.17 % (95 % CI, 23.97-50.46), respectively, against culture. The PPV and NPV were 44.44 % (95 % CI, 32-57.62) and 85 % (95 % CI, 63.96-94.76), respectively. Conclusion: TB-LAMP can be used instead of conventional microscopy for the diagnosis of TB in lymph node specimens at primary healthcare centres. It provides rapid and cost-effective diagnosis of LNTB in resource-limited settings due to good sensitivity and NPV.

8.
Curr Oncol ; 30(11): 9627-9633, 2023 Oct 31.
Artículo en Inglés | MEDLINE | ID: mdl-37999117

RESUMEN

While immunotherapies, such as CAR T therapy and bi-specific antibodies, have revolutionized the treatment of multiple myeloma (MM), patients with AL amyloidosis have been excluded from trials with these agents due to concerns of underlying autonomic, cardiac, and renal dysfunction, leading to potentially fatal toxicities from these therapies. In this communication, we described the outcomes of two patients with AL amyloidosis and concurrent MM with underlying cardiac and/or renal dysfunction who underwent anti-BCMA CAR T cell therapy with ide-cel or cilta-cel, received cytokine release syndrome prophylaxis, and tolerated therapy well with manageable toxicities and achieved a MRD-negative state. We described the preliminary efficacy and safety of CAR T in patients with AL amyloidosis and highlighted the importance of patient selection and medical optimization of cardiac and renal function prior to CAR T.


Asunto(s)
Amiloidosis de Cadenas Ligeras de las Inmunoglobulinas , Enfermedades Renales , Mieloma Múltiple , Receptores Quiméricos de Antígenos , Humanos , Mieloma Múltiple/terapia , Mieloma Múltiple/tratamiento farmacológico , Inmunoterapia Adoptiva/efectos adversos , Receptores Quiméricos de Antígenos/uso terapéutico , Amiloidosis de Cadenas Ligeras de las Inmunoglobulinas/complicaciones , Amiloidosis de Cadenas Ligeras de las Inmunoglobulinas/terapia , Antígeno de Maduración de Linfocitos B/uso terapéutico , Tratamiento Basado en Trasplante de Células y Tejidos , Enfermedades Renales/etiología
9.
Cancer Med ; 12(18): 19013-19020, 2023 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-37587868

RESUMEN

INTRODUCTION: Health information technology (HIT) has the potential to improve healthcare delivery and engagement. Studying racial-ethnic disparities in HIT engagement will help understand and overcome challenges to healthcare utilization. METHODS: We undertook a patient-reported survey among patients with lymphoid malignancies at two campuses of Mayo Clinic, Florida to explore HIT-related disparities. Variables between Whites and non-Whites, and non-Whites from the two campuses were compared. RESULTS: The survey was completed by 1004 respondents, with 71% whites, 27% non-Whites (race-ethnicity not reported by 2%). Non-Whites included 30% responders at the main campus and 64% at an inner-city campus. Whites were significantly older and had higher education, while non-Whites had lesser access to a computer. Only 51% of non-Whites were registered to use electronic medical records (EMR) as compared to 72% Whites (p < 0.001) and significantly lesser number of non-Whites even knew that EMR existed (81% vs. 92%, p < 0.001). Encouragingly, a higher number of non-Whites wanted to engage in EMR. Non-Whites from the main campus were older, more educated and had more access to a computer as compared to those from the inner-city campus. Similar disparate factors were noted among minorities from the two campuses, suggesting impact of socioeconomic backgrounds on EMR usage among non-Whites. Linguistic barriers were more striking among inner-city campus non-Whites. CONCLUSIONS: Non-Whites continue to struggle with suboptimal utilization of the healthcare system and barriers related to integration in HIT, including disparities representing socioeconomic differences. Efforts need to be made at several levels to help racial-ethnic minorities overcome awareness, access, and linguistic barriers to HIT utilization.

10.
J Stroke Cerebrovasc Dis ; 32(9): 107300, 2023 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-37572602

RESUMEN

BACKGROUND AND PURPOSE: Human amylin is a 37 amino-acid pancreatic peptide that forms neuro-toxic aggregates that deposit in the endothelium of brain capillaries of patients with diabetes, potentially contributing to cerebral small vessel ischemic injury. Pathogenic amylin also deposits in the capillary endothelium in other organs, including the skin. The aim of this study was to test the hypothesis that skin capillary amylin deposition correlates with cerebral small vessel amylin deposition, potentially providing a clinically useful marker of cerebral amylin deposition. METHODS: Immunohistochemistry (IHC) was performed for human amylin and collagen IV in brain and skin sections of rats (age 15-16 months) with pancreatic overexpression of amyloidogenic human amylin polypeptide (HIP rats), and control rats (Wild type; WT; rats that express non-amyloidogenic rat amylin) using antibodies binding amylin (n = 5 male and 5 female rats for each group) and antibodies binding Hypoxia inducing factor (HIF)-1α and HIF-2α (n = 3 for each group). The reactive amylin-aldehyde 4-hydroxynonenal (4-HNE) adduct was measured in skin homogenates. (n = 4 for each group) RESULTS: Brain capillaries isolated from HIP rats had higher amylin content compared to WT rats using Western blot with anti-amylin antibody (p = 0.0010). The HIF-1α and HIF-2α immunoreactivity signals in skin from HIP and WT rats were similar (p = 0.2 for HIF-1 α, and p = 0.75 for HIF-2α). Amylin-4HNE adduct formation was higher in HIP rats compared to WT rats (p = 0.0014). There was phenotypic similarity between brain and skin capillary amylin based on co-staining for human amylin and collagen IV in both HIP and WT rats. CONCLUSION: Skin and brain capillary amylin deposition are similar providing evidence that a skin biopsy might be providing a potential biomarker for diabetes-associated intracranial vasculopathy.


Asunto(s)
Capilares , Polipéptido Amiloide de los Islotes Pancreáticos , Ratas , Humanos , Masculino , Animales , Femenino , Lactante , Polipéptido Amiloide de los Islotes Pancreáticos/metabolismo , Capilares/metabolismo , Encéfalo/patología , Factores de Transcripción con Motivo Hélice-Asa-Hélice Básico/metabolismo , Colágeno/metabolismo
11.
J Stroke ; 25(2): 223-232, 2023 May.
Artículo en Inglés | MEDLINE | ID: mdl-37282372

RESUMEN

BACKGROUND AND PURPOSE: Intracranial arterial stenosis (ICAS)-related stroke occurs due to three primary mechanisms with distinct infarct patterns: (1) borderzone infarcts (BZI) due to impaired distal perfusion, (2) territorial infarcts due to distal plaque/thrombus embolization, and (3) plaque progression occluding perforators. The objective of the systematic review is to determine whether BZI secondary to ICAS is associated with a higher risk of recurrent stroke or neurological deterioration. METHODS: As part of this registered systematic review (CRD42021265230), a comprehensive search was performed to identify relevant papers and conference abstracts (with ≥20 patients) reporting initial infarct patterns and recurrence rates in patients with symptomatic ICAS. Subgroup analyses were performed for studies including any BZI versus isolated BZI and those excluding posterior circulation stroke. The study outcome included neurological deterioration or recurrent stroke during follow-up. For all outcome events, corresponding risk ratios (RRs) and 95% confidence intervals (95% CI) were calculated. RESULTS: A literature search yielded 4,478 records with 32 selected during the title/abstract triage for full text; 11 met inclusion criteria and 8 studies were included in the analysis (n=1,219 patients; 341 with BZI). The meta-analysis demonstrated that the RR of outcome in the BZI group compared to the no BZI group was 2.10 (95% CI 1.52-2.90). Limiting the analysis to studies including any BZI, the RR was 2.10 (95% CI 1.38-3.18). For isolated BZI, RR was 2.59 (95% CI 1.24-5.41). RR was 2.96 (95% CI 1.71-5.12) for studies only including anterior circulation stroke patients. CONCLUSION: This systematic review and meta-analysis suggests that the presence of BZI secondary to ICAS may be an imaging biomarker that predicts neurological deterioration and/or stroke recurrence.

13.
J Microbiol Methods ; 207: 106707, 2023 04.
Artículo en Inglés | MEDLINE | ID: mdl-36931327

RESUMEN

For enumerating viable bacteria, traditional dilution plating to count colony forming units (CFUs) has always been the preferred method in microbiology owing to its simplicity, albeit being laborious and time-consuming. Similar CFU counts can be obtained by quantifying growing micro-colonies in conjunction with the benefits of a microscope. Here, we employed a simple method of five to ten microliter spotting of a diluted bacterial culture multiple times on a single Petri dish followed by determining CFU by counting micro-colonies using a phase-contrast microscope. In this method, the CFU of an Escherichia coli culture can be estimated within a four-hour period after spotting. Further, within a ten-hour period after spotting, CFU in a culture of Ralstonia solanacearum, a bacterium with a generation time of around 2 h, can be estimated. The CFU number determined by micro-colonies observed for 106-fold dilutions or lower is similar to that obtained by the dilution plating method for 107-fold dilutions or lower. Micro-colony numbers observed in the early hours of growth (2 h in case of E. coli and 8 h in case of R. solanacearum) were found to remain consistent at later hours (4 h in case of E. coli and 10 h in case of R. solanacearum), where the visibility of the colonies was better due to a noticeable increase in the size of the colonies. This suggested that micro-colonies observed in the early hours indeed represent the bacterial number in the culture. Practical applications to this counting method were employed in studying the rifampicin-resistant mutation rate as well as performing a fluctuation test in E. coli. The spotting method described here to enumerate bacterial CFU results in reduction of labour, time and resources.


Asunto(s)
Bacterias , Escherichia coli , Recuento de Colonia Microbiana , Células Madre
14.
Chemistry ; 29(24): e202203820, 2023 Apr 25.
Artículo en Inglés | MEDLINE | ID: mdl-36786201

RESUMEN

An intricate synergism between multiple biochemical processes and physical conditions determines the formation and function of various biological self-assemblies. Thus, a complex set of variables dictate the far-from-equilibrium nature of these biological assemblies. Mimicking such systems synthetically is a challenging task. We report multi-stimuli responsive transient coacervation of an aldehyde-appended polymer and a short peptide. The coacervates are formed by the disulphide linkages between the peptide molecules and the imine bond between the polymer and the peptide. Imines are susceptible to pH changes and the disulphide bonds can be tuned by oxidation/reduction processes. Thus, the coacervation is operational only under the combined effect of appropriate pH and oxidative conditions. Taking advantage of these facts, the coacervates are transiently formed under a pH cycle (urea-urease/gluconolactone) and a non-equilibrium redox cycle (TCEP/H2 O2 ). Importantly, the system showed high adaptability toward environmental changes. The transient existence of the coacervates can be generated without any apparent change in size and shape within the same system through the sequential application of the above-mentioned nonequilibrium reaction cycles. Additionally, the coacervation allows for efficient encapsulation/stabilisation of proteins. Thus, the system has the potential to be used for protein/drug delivery purposes in the future.

15.
Stroke ; 54(6): 1685-1694, 2023 06.
Artículo en Inglés | MEDLINE | ID: mdl-36661035

RESUMEN

Occlusive and nonocclusive cervicocephalic thrombi can be encountered during neurovascular imaging in patients with acute ischemic stroke. Radiographic and morphological characteristics on basic and advanced imaging modalities can be important clues towards determination of pathomechanism and the choice of acute and subacute treatment modalities. The aim of this review article is to evaluate the epidemiology, radiographic properties, histologic clot composition of cervicocephalic arterial thrombi, and its response to various medical and endovascular therapy modalities. Future studies are needed to derive and validate a classification system for extracranial and intracranial partially occlusive thrombi to enable further testing of various stroke treatment and prevention strategies in these patients.


Asunto(s)
Isquemia Encefálica , Accidente Cerebrovascular Isquémico , Accidente Cerebrovascular , Trombosis , Humanos , Accidente Cerebrovascular/diagnóstico por imagen , Accidente Cerebrovascular/terapia , Accidente Cerebrovascular/epidemiología , Trombosis/patología , Isquemia Encefálica/diagnóstico por imagen , Isquemia Encefálica/terapia , Isquemia Encefálica/epidemiología
16.
DNA Res ; 29(4)2022 Jun 25.
Artículo en Inglés | MEDLINE | ID: mdl-35920776

RESUMEN

A common approach to estimate the strength and direction of selection acting on protein coding sequences is to calculate the dN/dS ratio. The method to calculate dN/dS has been widely used by many researchers and many critical reviews have been made on its application after the proposition by Nei and Gojobori in 1986. However, the method is still evolving considering the non-uniform substitution rates and pretermination codons. In our study of SNPs in 586 genes across 156 Escherichia coli strains, synonymous polymorphism in 2-fold degenerate codons were higher in comparison to that in 4-fold degenerate codons, which could be attributed to the difference between transition (Ti) and transversion (Tv) substitution rates where the average rate of a transition is four times more than that of a transversion in general. We considered both the Ti/Tv ratio, and nonsense mutation in pretermination codons, to improve estimates of synonymous (S) and non-synonymous (NS) sites. The accuracy of estimating dN/dS has been improved by considering the Ti/Tv ratio and nonsense substitutions in pretermination codons. We showed that applying the modified approach based on Ti/Tv ratio and pretermination codons results in higher values of dN/dS in 29 common genes of equal reading-frames between E. coli and Salmonella enterica. This study emphasizes the robustness of amino acid composition with varying codon degeneracy, as well as the pretermination codons when calculating dN/dS values.


Asunto(s)
Proteínas de Escherichia coli , Selección Genética , Codón , Codón sin Sentido , Desoxirribonucleasa (Dímero de Pirimidina)/genética , Escherichia coli/genética , Evolución Molecular , Modelos Genéticos
17.
Chem Asian J ; 17(18): e202200550, 2022 Sep 14.
Artículo en Inglés | MEDLINE | ID: mdl-35871609

RESUMEN

Leishmaniasis, caused by the intramacrophage protozoan parasite Leishmania donovani, is a life-threatening yet neglected vector-borne disease. Few medications for the treatment of this disease are available. However, targeted delivery of drugs to macrophages remains a significant concern. Macrophages are equipped with many receptors, and therefore putting suitable ligands in the macrophage targeting drug delivery vehicle gained a lot of attention. One such receptor is the mannose receptor, abundantly expressed by macrophages. To treat this deadly disease, in this study, a mannose containing composite hydrogel is prepared by combining a self-aggregating short peptide (Nap-FFGE-NH2 , Pep-A) and a mannose containing non-aggregating peptide (Nap-FF-mannosyl, Pep-B). The self-aggregation of the composite hydrogel is evaluated using various spectroscopic and microscopic techniques. Intermolecular hydrogen bonding and π-π stacking lead to an antiparallel ß-sheet like arrangement of the peptides. Notably, the composite hydrogel showed shear-thinning and syneresis properties. Moreover, the composite hydrogel was found to be stable in cell-culture media, biodegradable and non-toxic to the macrophages. Both control and infected macrophages showed effective cell growth and proliferation when subjected to the composite 2D and 3D hydrogel matrix. When treated with Amphotericin B loaded composite hydrogel, the drug was effectively delivered to kill the parasite in the infected macrophages. Almost 3.5 fold decrease in the parasite burden was recorded when infected cells were treated with drug-loaded composite hydrogel. The injectability, biodegradability, non-cytotoxicity, and efficient drug delivery properties of the mannose-functionalized hydrogel make it a suitable candidate for the treatment of Leishmaniasis.


Asunto(s)
Leishmaniasis Visceral , Leishmaniasis , Humanos , Hidrogeles , Leishmaniasis/tratamiento farmacológico , Leishmaniasis Visceral/tratamiento farmacológico , Leishmaniasis Visceral/parasitología , Manosa/química , Manosa/farmacología , Péptidos/farmacología
20.
Chem Sci ; 13(14): 4050-4057, 2022 Apr 06.
Artículo en Inglés | MEDLINE | ID: mdl-35440999

RESUMEN

Nature has evolved a unique mechanism of self-regulatory feedback loops that help in maintaining an internal cellular environment conducive to growth, healing and metabolism. In biology, enzymes display feedback controlled switchable behaviour to upregulate/downregulate the generation of metabolites as per the need of the cells. To mimic the self-inhibitory nature of certain biological enzymes under laboratory settings, herein, we present a cucurbit[8]uril based pH responsive supramolecular peptide amphiphile (SPA) that assembles into hydrolase mimetic vesicular nanozymes upon addition of alkaline TRIS buffer (activator) but disintegrates gradually owing to the catalytic generation of acidic byproducts (deactivator). The lifetime of these nanozymes could be manipulated in multiple ways, either by varying the amount of catalytic groups on the surface of the vesicles, by changing the acid generating substrate, or by changing the ratio between the activator and the substrate. The self-inhibitory nanozymes displayed highly tunable lifetimes ranging from minutes to hours, controlled and in situ generation of deactivating agents and efficient reproducibility across multiple pH cycles.

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