An Aptamer-Based Biosensor for the Azole Class of Antifungal Drugs

ABSTRACT We have developed the first aptamer directed toward the azole class of antifungal drugs and a functional biosensor for these drugs. This aptamer has a unique secondary structure that allows it to bind to highly hydrophobic drugs. The aptamer works as a capture component of a graphene field effect transistor device. These devices can provide a quick and easy assay for determining drug concentrations. These will be useful for therapeutic drug monitoring of azole antifungal drugs, which is necessary to deal with the complex drug dosage profiles. This technical report describes the development of an aptamer for sensing azole antifungal drugs during therapeutic drug monitoring. Modified synthetic evolution of ligands through exponential enrichment (SELEX) was used to discover a DNA aptamer recognizing azole class antifungal drugs. This aptamer undergoes a secondary structural change upon binding to its target molecule, as shown through fluorescence anisotropy-based binding measurements. Experiments using circular dichroism spectroscopy revealed a unique G-quadruplex structure that was essential and specific for binding to the azole antifungal target. Aptamer-functionalized graphene field effect transistor (GFET) devices were created and used to measure the strength of binding of azole antifungals to this surface. In total, this aptamer and the supporting sensing platform provide a valuable tool for therapeutic drug monitoring of patients with invasive fungal infections. IMPORTANCE We have developed the first aptamer directed toward the azole class of antifungal drugs and a functional biosensor for these drugs. This aptamer has a unique secondary structure that allows it to bind to highly hydrophobic drugs. The aptamer works as a capture component of a graphene field effect transistor device. These devices can provide a quick and easy assay for determining drug concentrations. These will be useful for therapeutic drug monitoring of azole antifungal drugs, which is necessary to deal with the complex drug dosage profiles.

Download Full-text

Immunosuppressant quantification in intravenous microdialysate – towards novel quasi-continuous therapeutic drug monitoring in transplanted patients

Clinical Chemistry and Laboratory Medicine (CCLM) ◽

10.1515/cclm-2020-1542 ◽

2020 ◽

Vol 0 (0) ◽

Author(s):

Susanne Weber ◽

Sara Tombelli ◽

Ambra Giannetti ◽

Cosimo Trono ◽

Mark O’Connell ◽

...

Keyword(s):

Therapeutic Drug Monitoring ◽

Real Time ◽

Drug Monitoring ◽

Time Course ◽

Drug Dosage ◽

Immunosuppressive Drug ◽

Therapeutic Drug ◽

Continuous Sampling ◽

Real Time Analysis ◽

Drug Concentrations

AbstractObjectivesTherapeutic drug monitoring (TDM) plays a crucial role in personalized medicine. It helps clinicians to tailor drug dosage for optimized therapy through understanding the underlying complex pharmacokinetics and pharmacodynamics. Conventional, non-continuous TDM fails to provide real-time information, which is particularly important for the initial phase of immunosuppressant therapy, e.g., with cyclosporine (CsA) and mycophenolic acid (MPA).MethodsWe analyzed the time course over 8 h of total and free of immunosuppressive drug (CsA and MPA) concentrations measured by liquid chromatography-tandem mass spectrometry (LC-MS/MS) in 16 kidney transplant patients. Besides repeated blood sampling, intravenous microdialysis was used for continuous sampling. Free drug concentrations were determined from ultracentrifuged EDTA-plasma (UC) and compared with the drug concentrations in the respective microdialysate (µD). µDs were additionally analyzed for free CsA using a novel immunosensor chip integrated into a fluorescence detection platform. The potential of microdialysis coupled with an optical immunosensor for the TDM of immunosuppressants was assessed.ResultsUsing LC-MS/MS, the free concentrations of CsA (fCsA) and MPA (fMPA) were detectable and the time courses of total and free CsA comparable. fCsA and fMPA and area-under-the-curves (AUCs) in µDs correlated well with those determined in UCs (r≥0.79 and r≥0.88, respectively). Moreover, fCsA in µDs measured with the immunosensor correlated clearly with those determined by LC-MS/MS (r=0.82).ConclusionsThe new microdialysis-supported immunosensor allows real-time analysis of immunosuppressants and tailor-made dosing according to the AUC concept. It readily lends itself to future applications as minimally invasive and continuous near-patient TDM.

Download Full-text

Therapeutic Drug Monitoring in Fungal Infections: the Dawn of Proactive Monitoring

10.20944/preprints202105.0554.v1 ◽

2021 ◽

Author(s):

Joan Antoni Schoenenberger-Arnaiz ◽

Ana Aragones-Eroles ◽

Pilar Taberner-Bonastre ◽

Arturo Morales-Portillo

Keyword(s):

Clinical Practice ◽

Therapeutic Drug Monitoring ◽

Drug Monitoring ◽

Fungal Infections ◽

Antifungal Drugs ◽

Therapeutic Drug ◽

Clinical Settings ◽

Drug Concentrations ◽

Direct Exposure ◽

Consensus Statements

Therapeutic Drug Monitoring (TDM) is potentially a useful tool that can be employed to increase the efficacy and decrease the toxicity of antifungal drugs. The aim of this narrative review is to provide an overview of the current use of TDM in clinical practice, and to present the evidence available regarding its use in proactive clinical settings for preventing and managing treatment failure. This review also presents the existing evidence regarding the association of various clinical outcomes with specific thresholds of drug concentrations in everyday practice. Articles concerning the use of TDM of triazoles in the treatment of fungal infections were retrieved through an electronic search using PubMed. In clinical practice, TDM has an increasingly important role in the management of antifungal drugs as a consequence of the improvement in the knowledge of the pharmacokinetics and pharmacodynamics of these drugs. The currently available evidence shows a direct exposure-response relationship for triazoles, though the PK/PD profile is unpredictable. Current guidelines and treatment consensus statements recommend the proactive TDM of voriconazole, posaconazole, and itraconazole to optimize dosage regimens and improve outcomes for adult and pediatric patients.

Download Full-text

Real-time label-free detection of DNA hybridization using a functionalized graphene field effect transistor: a theoretical study

Journal of Nanoparticle Research ◽

10.1007/s11051-021-05295-1 ◽

2021 ◽

Vol 23 (8) ◽

Author(s):

Sheida Bagherzadeh-Nobari ◽

Reza Kalantarinejad

Keyword(s):

Real Time ◽

Dna Hybridization ◽

Field Effect ◽

Field Effect Transistor ◽

Theoretical Study ◽

Functionalized Graphene ◽

Label Free ◽

Graphene Field Effect Transistor ◽

Label Free Detection ◽

Effect Transistor

Download Full-text

Investigating electrical performance and breakdown characteristic of graphene field-effect transistor with different oxides structure

Physics Letters A ◽

10.1016/j.physleta.2021.127139 ◽

2021 ◽

pp. 127139

Author(s):

Yongzhong Fu ◽

Zhongxue Li ◽

Quan Wang

Keyword(s):

Field Effect ◽

Field Effect Transistor ◽

Electrical Performance ◽

Graphene Field Effect Transistor ◽

Effect Transistor

Download Full-text

Demonstration of programmable ternary graphene field-effect transistor using ferroelectric polymer doping

Organic Electronics ◽

10.1016/j.orgel.2021.106157 ◽

2021 ◽

pp. 106157

Author(s):

So-Young Kim ◽

Jiae Yoo ◽

Hyeon Jun Hwang ◽

Byoung Hun Lee

Keyword(s):

Field Effect ◽

Field Effect Transistor ◽

Ferroelectric Polymer ◽

Graphene Field Effect Transistor ◽

Effect Transistor

Download Full-text

Graphene field effect transistor as a radiation and photodetector

10.1117/12.919628 ◽

2012 ◽

Cited By ~ 7

Author(s):

Ozhan Koybasi ◽

Isaac Childres ◽

Igor Jovanovic ◽

Yong P. Chen

Keyword(s):

Field Effect ◽

Field Effect Transistor ◽

Graphene Field Effect Transistor ◽

Effect Transistor

Download Full-text

Rapid point-of-care anti-infliximab antibodies detection in clinical practice: comparison with ELISA and potential for improving therapeutic drug monitoring in IBD patients

Therapeutic Advances in Gastroenterology ◽

10.1177/1756284821999902 ◽

2021 ◽

Vol 14 ◽

pp. 175628482199990

Author(s):

Sonia Facchin ◽

Andrea Buda ◽

Romilda Cardin ◽

Nada Agbariah ◽

Fabiana Zingone ◽

...

Keyword(s):

Clinical Practice ◽

Therapeutic Drug Monitoring ◽

Drug Monitoring ◽

Point Of Care ◽

Drug Clearance ◽

Elisa Test ◽

Enzyme Linked Immunosorbent Assay ◽

Therapeutic Drug ◽

Drug Concentrations ◽

Inflammatory Bowel

Anti-drug antibodies can interfere with the activity of anti-tumor necrosis factor (TNF) agents by increasing drug clearance via direct neutralization. The presence of anti-drug antibodies is clinically relevant when trough drug concentrations are undetectable or sub-therapeutic. However, traditional immunoassay is not easily and rapidly accessible, making the translation of the results into treatment adjustment difficult. The availability of a point-of-care (POC) test for therapeutic drug monitoring (TDM) might represent an important step forward for improving the management of inflammatory bowel disease (IBD) patients in clinical practice. In this pilot study, we compared the results obtained with POC tests with those obtained by enzyme-linked immunosorbent assay (ELISA) in a group of IBD patients treated with Infliximab (IFX). We showed that POC test can reliably detect presence of antibody-to-IFX with 100% of specificity and 76% sensitivity, in strong agreement with the ELISA test ( k-coefficient = 0.84).

Download Full-text