A competition-format microarray assay on a poly(oligo(ethylene glycol) methacrylate-co-glycidyl methacrylate-co-glycidyl methacrylate brush integrated into a single-use microfluidic cassette and portable reader to quantify vancomycin directly from fingerstick volumes of whole blood in 30 min.
Abstract
Summary Vancomycin requires individualized dosing guided by therapeutic drug monitoring, but current laboratory assays are slow and centralized. We describe a competition-format microarray assay on a poly(oligo(ethylene glycol) methacrylate-co-glycidyl methacrylate) brush integrated into a single-use microfluidic cassette and portable reader to quantify vancomycin directly from fingerstick volumes of whole blood in 30 min. The assay shows a limit of detection of 0.8 μg/mL and precise quantification across the clinical range, with relative error below 20%. In a pilot study of 31 patient samples, cassette measurements correlated strongly with routine hospital testing with minimal bias, including when operated by minimally trained coordinators. This work establishes an approach for rapid, decentralized vancomycin monitoring that could support area-under-the-curve-based dosing in settings where access to high-complexity laboratories is limited and suggests a path toward extending therapeutic drug monitoring to point-of-care devices.
Background The global rise of multidrug-resistant (MDR) infections has intensified the clinical reliance on last-resort antibiotics such as vancomycin, linezolid, and tigecycline, particularly in critically ill patients. These agents possess narrow therapeutic windows, complex pharmacokinetics, and substantial inter-patient variability, making therapeutic drug monitoring (TDM) a cornerstone of individualized therapy. Traditional TDM methodologies though accurate are often limited by centralized processing, slow turnaround times, and cost constraints, which hinder real-time clinical decision-making in intensive care settings. Objective This review aims to critically evaluate emerging bioanalytical platforms, modeling frameworks, and decision-support systems for optimizing TDM of last-resort antibiotics. It focuses on enhancing precision dosing, improving clinical outcomes, and addressing antimicrobial resistance through integration of innovative sensor technologies and artificial intelligence. Methods A comprehensive literature search was conducted across databases, including PubMed, Google Scholar, Scopus, and Nature. Relevant studies were analyzed for analytical techniques, matrix types, extraction strategies, assay validation parameters, and clinical applicability. Emphasis was placed on comparing high-performance liquid chromatography (HPLC), LC–MS/MS, and immunoassays with novel approaches such as microneedle-based biosensors, real-time urinary antibiotic monitoring, wearable devices, and luciferase-based bioluminescent sensors. Mechanism-based pharmacokinetic/pharmacodynamic (PK/PD) modelling and Bayesian forecasting frameworks were reviewed for their role in adaptive dosing. Results LC–MS/MS emerged as the most sensitive and specific platform, while immunoassays provided practical solutions for near-patient testing. Innovations such as microsampling, temperature-responsive two-dimensional chromatography, and bioluminescent sensor platforms demonstrated potential to overcome the limitations of conventional assays. Integration of population pharmacokinetic (PPK) models and AI-driven decision-support algorithms enhanced predictive precision, allowing dynamic dose optimization for β-lactam antibiotics, tetracyclines, vancomycin, linezolid, and tigecycline. A three-tiered TDM model was proposed, combining site-specific sensing, real-time analysis, and computational forecasting to improve antimicrobial stewardship. Conclusion Emerging bioanalytical technologies and predictive PK/PD modeling are transforming TDM from a static laboratory tool into a real-time, precision-guided clinical decision platform. The integration of minimally invasive sensing technologies with AI-enabled dose optimization offers a path toward personalized antibiotic therapy, optimized clinical outcomes, and the mitigation of antimicrobial resistance in critical care settings. This paradigm shift supports a more adaptive and responsive approach to TDM, ensuring last-resort antibiotics are used effectively and sustainably.
Aparna Inamdar, N. Beeraka, P. Vikram et al.· Frontiers in Pharmacology· 0 citations
: Point-of-care molecular diagnostics (POC-MDx) have transformed infectious disease diagnosis by enabling rapid, accurate pathogen detection at or near the patient care site. Unlike conventional laboratory-based molecular tests, POC molecular platforms provide clinically actionable results within minutes to hours, facilitating timely antimicrobial therapy, improving patient outcomes, and strengthening antimicrobial stewardship (AMS). Recent advances in nucleic acid amplification technologies, microfluidics, isothermal amplification, CRISPR-based diagnostics, and portable sequencing platforms have expanded the applications of POC molecular testing across emergency departments, intensive care units, outpatient clinics, and resource-limited settings. Despite these advances, challenges related to cost, quality assurance, interpretation of results, and integration into clinical workflows remain. This review summarizes the current evidence supporting POC molecular diagnostics and explores future innovations that are likely to redefine infectious disease management.
Yogesh Kumar Gupta· International Journal of Sci...· 0 citations
Rapid point-of-care diagnostics that operate directly on whole blood can accelerate clinical decision-making by bypassing complex sample preprocessing and centralized laboratory infrastructure. However, most serologic assays still require serum or plasma, limiting near-patient deployment. This challenge is particularly evident for Lyme disease, whose diagnosis relies on centralized two-tier serology. Here, we present a whole-blood multiplexed vertical flow assay (WB-xVFA) that performs single-tier Lyme serology directly from 50 microliter of whole blood. The assay combines multilayer blood filtration with a peptide-patterned nitrocellulose membrane to separate cellular components and detect Lyme-associated IgM/IgG responses on a cartridge. Coupled with smartphone-based imaging and machine-learning analysis, the WB-xVFA provides results in 20 min. The assay remained robust across hematocrits up to 60% and sample volumes ranging from 25 to 100 microliter. In blinded testing of 62 whole-blood measurements, it achieved ~97% sensitivity and specificity, demonstrating the feasibility of rapid, near-patient whole-blood Lyme serology.
Mihye Lee, R. Ghosh, Artem Goncharov et al.· 0 citations
Tacrolimus is a cornerstone immunosuppressant used to prevent graft rejection in solid organ transplant recipients. While effective, tacrolimus therapy must be carefully monitored and managed due to the drug's narrow therapeutic window and variable patient responses to dosing. Overdosing of tacrolimus can lead to opportunistic infections, nephrotoxicity, neurotoxicity, and cancer while under-dosing risks organ rejection. As a result, therapeutic drug monitoring (TDM) of tacrolimus is routinely performed. Current monitoring approaches face significant limitations, including slow (4-8 h or days) turnaround times, complex sample preparation requirements, and reliance on centralized infrastructure that delays critical dosing decisions. Furthermore, emerging evidence shows that the pharmacokinetic exposure parameter best associated with clinical outcomes is the area under the concentration-time curve (AUC). AUC-based monitoring requires sampling patients at multiple time points, which increases the logistical burdens to both patients and providers. Hence, there is an urgent need for a point-of-care test for tacrolimus that can be run at the patient bedside, in outpatient clinics, and eventually in patient homes. Here, we describe a novel point-of-care test, the TAC-D4 POCT, capable of measuring tacrolimus levels directly from whole blood samples without sample preparation steps or expensive analyzers with automated results available in 1 h. Our test helps overcome the current logistical barriers in the clinical management of patients receiving tacrolimus therapy ultimately leading to improved patient adherence, outcomes, and the ability to further personalize dosing regimens. Moreover, the Tac-D4 is highly modular and can be used to monitor clinically significantly biomarkers, such as interleukin-6 and matrix metalloproteinase 3, that complement tacrolimus TDM.
Damon T. Burrow, David S. Kinnamon, Jacob T. Heggestad et al.· Analytical Chemistry· 0 citations
Background: Rapid and accurate measurement of procalcitonin (PCT) is useful for diagnosing bacterial infections and guiding antibiotic therapy, yet current laboratory-based immunoassays require centralised infrastructure, delaying clinical decision-making and limiting access in low-resource settings. We developed a battery-free, smartphone-connected electrochemical lateral flow assay with linked analytics for the detection of PCT (ELLA-PCT) enabling quantitative testing at the point of care without conventional laboratory instrumentation. Methods: We designed a competitive electrochemical lateral flow assay using gold nanoparticles co-functionalised with a PCT-specific DNA aptamer and ferrocene hexanethiol as a redox reporter. A miniaturised near-field communication (NFC) potentiostat embedded within a disposable cassette enabled wireless electroanalytical measurements using a smartphone. Analytical performance was assessed in buffer and serum, including limit of detection (LOD), linearity, specificity, and stability. Clinical evaluation was performed on 27 serum samples from nine adults undergoing antibiotic treatment for suspected bacterial infection, with results compared against the reference Time-Resolved Amplified Cryptate Emission (TRACE) assay. Findings: ELLA-PCT achieved an LOD of 46 pg/mL and a linear detection range of 0.5-100 ng/mL. The ELLA-PCT assays remained stable for three months under ambient storage conditions, and cross-reactivity with calcitonin, C-reactive protein, and interleukin-6 remained below clinically relevant thresholds. Clinical results showed strong correlation with TRACE (R2 = 0.979, p < 0.0001), with a mean bias of 0.05 ng/mL and narrow 95% limits of agreement (-0.69 to 0.89 ng/mL). Importantly, ELLA-PCT delivered results in only 30 minutes without requiring external power or clinical laboratory instrumentation. In comparison to TRACE, the total turnaround time was reduced by at least 50%, which typically requires at least one hour from sample collection to results at a hospital setting. Interpretation: ELLA-PCT is an antibody-free, smartphone-connected test that provides laboratory-grade quantitative PCT measurement using only an NFC-enabled electroanalytical sensor and a mobile phone. The platform has a strong potential to decentralise diagnosis of infectious diseases, support antibiotic stewardship, and enable remote, real-time monitoring in outpatient and resource-limited settings. Larger studies are needed to evaluate the use of whole-blood samples and the integration of the platform into digital clinical workflows.
Y. Cai, J. Flauzino, A. Şanli et al.· medRxiv· 0 citations
The FDA has recently approved a medical device which determines a glomerular filtration rate assessment at the point-of-care by transdermal detection of the fluorescent tracer agent relmapirazin. Previous in vitro and in vivo studies on this agent yielded negligible safety/toxicology concern resulting in advancement to phase I, II, and III human clinical studies. Now that clinical use is occurring, herein we investigated possible interference this agent may induce with typical clinical diagnostic assays given to incoming and hospitalized patients. The testing methodology followed the CLSI EP07-A3 Interference Testing in Clinical Chemistry guideline for determination of interference. No interference from relmapirazin was detected in the suite of metabolic and cardiac assays evaluated.
R. Dorshow, Nancy Morrison, Margot Borgel· International journal of tox...· 0 citations
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