Point-of-Care Drug of Abuse Testing in the Opioid Epidemic

Highly multiplexed design of an allosteric transcription factor to sense novel ligands

Allosteric transcription factors (aTF), widely used as biosensors, have proven challenging to design for detecting novel molecules because mutation of ligand-binding residues often disrupts allostery. We developed Sensor-seq, a high-throughput platform to design and identify aTF biosensors that bind to non-native ligands. We screened a library of 17,737 variants of the aTF TtgR, a regulator of a multidrug exporter, against six non-native ligands of diverse chemical structures - four derivatives of the cancer therapeutic tamoxifen, the antimalarial drug quinine, and the opiate analog naltrexone - as well as two native flavonoid ligands, naringenin and phloretin. Sensor-seq identified novel biosensors for each of these ligands with high dynamic range and diverse specificity profiles. The structure of a naltrexone-bound design showed shape-complementary methionine-aromatic interactions driving ligand specificity. To demonstrate practical utility, we developed cell-free detection systems for naltrexone and quinine. Sensor-seq enables rapid, scalable design of new biosensors, overcoming constraints of natural biosensors.

Detection of contraband drugs in forensic-correctional mental health services using TeknoScan-a gas chromatography tool

Substance misuse is a major problem among individuals involved in forensic-correctional mental health services. Urine drug screening detects substance use and deters the entry of contraband into forensic-correctional units, albeit with limitations. For example, a point-of-care urine sample may not be possible and patients can alter or substitute samples to avoid detection, highlighting the role of ancillary tools to detect contraband substances. This study describes the pattern and types of substances detected from environmental samples using a gas chromatographic analyzer (TeknoScan TSI3000) in forensic-correctional populations to model the benefits of similar tools in similar settings. Samples collected over 18 months (January 2020 to June 2021) by trained staff members using the machine were reviewed. During this period, 217 environmental samples were recorded, and 66 (30%) samples were positive for contraband substances, including tetrahydrocannabinol (25%), methamphetamines (19%), and cocaine (16%). Other substances detected include methylene-dioxymethamphetamine, heroin, morphine, lysergic acid diethylamide, tramadol, and methyl-benzoate. Fewer positive samples were detected, especially during the time corresponding with the COVID-19 restriction on the forensic units. TeknoScan was beneficial as an ancillary tool to detect and deter contraband substances. It also provided evidence for risk management. Adequate training is needed for the successful implementation of the tool.

Comparative effectiveness of urine drug screening strategies alongside opioid agonist treatment in British Columbia, Canada: a population-based observational study protocol

INTRODUCTION

Urine drug tests (UDTs) are commonly used for monitoring opioid agonist treatment (OAT) responses, supporting the clinical decision for take-home doses and monitoring potential diversion. However, there is limited evidence supporting the utility of mandatory UDTs-particularly the impact of UDT frequency on OAT retention. Real-world evidence can inform patient-centred approaches to OAT and improve current strategies to address the ongoing opioid public health emergency. Our objective is to determine the safety and comparative effectiveness of alternative UDT monitoring strategies as observed in clinical practice among OAT clients in British Columbia, Canada from 2010 to 2020.

METHODS AND ANALYSIS

We propose a population-level retrospective cohort study of all individuals 18 years of age or older who initiated OAT from 1 January 2010 to 17 March 2020. The study will draw on eight linked health administrative databases from British Columbia. Our primary outcomes include OAT discontinuation and all-cause mortality. To determine the effectiveness of the intervention, we will emulate a 'per-protocol' target trial using a clone censoring approach to compare fixed and dynamic UDT monitoring strategies. A range of sensitivity analyses will be executed to determine the robustness of our results.

ETHICS AND DISSEMINATION

The protocol, cohort creation and analysis plan have been classified and approved as a quality improvement initiative by Providence Health Care Research Ethics Board and the Simon Fraser University Office of Research Ethics. Results will be disseminated to local advocacy groups and decision-makers, national and international clinical guideline developers, presented at international conferences and published in peer-reviewed journals electronically and in print.

Deep learning-assisted sensitive detection of fentanyl using a bubbling-microchip

Deep learning-enabled smartphone-based image processing has significant advantages in the development of point-of-care diagnostics. Conventionally, most deep-learning applications require task specific large scale expertly annotated datasets. Therefore, these algorithms are oftentimes limited only to applications that have large retrospective datasets available for network development. Here, we report the possibility of utilizing adversarial neural networks to overcome this challenge by expanding the utility of non-specific data for the development of deep learning models. As a clinical model, we report the detection of fentanyl, a small molecular weight drug that is a type of opioid, at the point-of-care using a deep-learning empowered smartphone assay. We used the catalytic property of platinum nanoparticles (PtNPs) in a smartphone-enabled microchip bubbling assay to achieve high analytical sensitivity (detecting fentanyl at concentrations as low as 0.23 ng mL-1 in phosphate buffered saline (PBS), 0.43 ng mL-1 in human serum and 0.64 ng mL-1 in artificial human urine). Image-based inferences were made by our adversarial-based SPyDERMAN network that was developed using a limited dataset of 104 smartphone images of microchips with bubble signals from tests performed with known fentanyl concentrations and using our retrospective library of 17 573 non-specific bubbling-microchip images. The accuracy (± standard error of mean) of the developed system in determining the presence of fentanyl, when using a cutoff concentration of 1 ng mL-1, was 93 ± 0% in human serum (n = 100) and 95.3 ± 1.5% in artificial human urine (n = 100).

Nanobiosensors for detection of opioids: A review of latest advancements

Opioids are generally used as analgesics in pain treatment. Like many drugs, they have side effects when overdosing and causeaddiction problems.Illegal drug use and misuse are becoming a major concern for authorities worldwide; thus, it is critical to have precise procedures for detecting them in confiscated samples, biological fluids, and wastewaters. Routine blood and urine tests are insufficient for highly selective determinations and can cause cross-reactivities. For this purpose, nanomaterial-based biosensors are great tools to determine opioid intakes, continuously monitoring the drugs with high sensitivity and selectivity even at very low sample volumes.Nanobiosensors generally comprise a signal transducer nanostructure in which a biological recognition molecule is immobilized onto its surface. Lately, nanobiosensors have been extensively utilized for the molecular detection of opioids. The usage of novel nanomaterials in biosensing has impressed biosensing studies. Nanomaterials with a large surface area have been used to develop nanobiosensors with shorter reaction times and higher sensitivity than conventional biosensors. Colorimetric and fluorescence sensing methods are two kinds of optical sensor systems based on nanomaterials. Noble metal nanoparticles (NPs), such as silver and gold, are the most frequently applied nanomaterials in colorimetric techniques, owing to their unique optical feature of surface plasmon resonance. Despite the progress of an extensive spectrum of nanobiosensors over the last two decades, the future purpose of low-cost, high-throughput, multiplexed clinical diagnostic lab-on-a-chip instruments has yet to be fulfilled. In this review, a concise overview of opioids (such as tramadol and buprenorphine, oxycodone and fentanyl, methadone and morphine) is provided as well as information on their classification, mechanism of action, routine tests, and new opioid sensing technologies based on various NPs. In order to highlight the trend of nanostructure development in biosensor applications for opioids, recent literature examples with the nanomaterial type, target molecules, and limits of detection are discussed.

Current and Future Perspective of Devices and Diagnostics for Opioid and OIRD

OIRD (opioid-induced respiratory depression) remains a significant public health concern due to clinically indicated and illicit opioid use. Respiratory depression is the sine qua non of opioid toxicity, and early detection is critical for reversal using pharmacologic and non-pharmacologic interventions. In addition to respiratory monitoring devices such as pulse oximetry, capnography, and contactless monitoring systems, novel implantable sensors and detection systems such as optical detection and electrochemical detection techniques are being developed to identify the presence of opioids both in vivo and within the environment. These new technologies will not only monitor for signs and symptoms of OIRD but also serve as a mechanism to alert and assist first responders and lay rescuers. The current opioid epidemic brings to the forefront the need for additional accessible means of detection and diagnosis. Rigorous evaluation of safety, efficacy, and acceptability will be necessary for both new and established technologies to have an impact on morbidity and mortality associated with opioid toxicity. Here, we summarized existing and advanced technologies for opioid detection and OIRD management with a focus on recent advancements in wearable and implantable opioid detection. We expect that this review will serve as a complete informative reference for the researchers and healthcare professionals working on the subject and allied fields.

The North American opioid epidemic: opportunities and challenges for clinical laboratories

Since 1999, the opioid epidemic in North America has resulted in over 1 million deaths, and it continues to escalate despite numerous efforts in various arenas to combat the upward trend. Clinical laboratories provide drug testing to support practices such as emergency medicine, substance use disorder treatment, and pain management; increasingly, these laboratories are collaborating in novel partnerships including drug-checking services (DCS) and multidisciplinary treatment teams. This review examines drug testing related to management of licit and illicit opioid use, new technologies and test strategies employed by clinical laboratories, barriers hindering laboratory response to the opioid epidemic, and areas for improvement and standardization within drug testing. Literature search terms included combinations of "opioid," "opiate," "fentanyl," "laboratory," "epidemic," "crisis," "mass spectrometry," "immunoassay," "drug screen," "drug test," "guidelines," plus review of PubMed "similar articles" and references within publications. While immunoassay (IA) and point-of-care (POC) test options for synthetic opioids are increasingly available, mass spectrometry (MS) platforms offer the greatest flexibility and sensitivity for detecting novel, potent opioids. Previously reserved as a second-tier application in most drug test algorithms, MS assays are gaining a larger role in initial screening for specific patients and DCS. However, there are substantial differences among laboratories in terms of updating test menus, algorithms, and technologies to meet changing clinical needs. While some clinical laboratories lack the resources and expertise to implement MS, many are also slow to adopt available IA and POC tests for newer opioids such as fentanyl. MS-based testing also presents challenges, including gaps in available guidance for assay validation and ongoing performance assessment that contribute to a dramatic lack of standardization among laboratories. We identify opportunities for improvement in laboratory operations, reporting, and interpretation of drug test results, including laboratorian and provider education and laboratory-focused guidelines. We also highlight the need for collaboration with providers, assay and instrument manufacturers, and national organizations to increase the effectiveness of clinical laboratory and provider efforts in preventing morbidity and mortality associated with opioid use and misuse.

Comparative Analyses of Three Point-of-Care Urine Drug Test Devices' Performance Characteristics for Use in Ambulatory Clinic Settings

BACKGROUND

Urine drug testing (UDT) is a standard practice used for monitoring controlled and illicit substances in ambulatory care patients. Point-of-care (POC) UDTs are useful tools that allow for drug identification within minutes, providing rapid and objective diagnostic assistance for clinicians. The objective of this study was to evaluate the performance characteristics of 3 different POC UDT devices compared to reference methods.

METHODS

A total of 106 residual urine specimens were collected to evaluate the 3 POC UDT devices: the Profile®-V MEDTOX Scan® drugs of abuse test, Quidel Triage® TOX Drug screen, and Quidel Triage Rapid OXY-BUP-MDMA panel. Device performance was assessed by their ability to identify drug classes/compounds compared to manufacturer and reference method (mass spectrometry) cutoffs.

RESULTS

The results from quantitative mass spectrometry showed that 77% (84/106) of the samples were positive for one or more drugs. Each device had variable performance across each drug class. Overall, the specificity of the Profile-V MEDTOX Scan test was 90.1%, while the Quidel Triage TOX Drug Screen and Rapid OXY-BUP-MDMA devices had specificities of 89.0% and 50.0% using their respective manufacturer-stated cutoffs. Overall sensitivity was determined to be 98.6%, 97.0%, and 100% for the Profile-V MEDTOX Scan, Quidel Triage TOX Drug Screen, and Rapid OXY-BUP-MDMA, respectively.

CONCLUSIONS

Of the 3 POC UDT devices evaluated, the Profile-V MEDTOX Scan demonstrated the best overall sensitivity and specificity compared to reference methods. False positive and negative results are possible with UDTs, ultimately the best device may depend on patient population and drugs of interest.