Evaluation of a Rapid Drug Test Device for Urine Fentanyl Compared to Mass Spectrometry and 2 Urine Fentanyl Assays.

BACKGROUND: A new Rapid Drug Test Device (RDTD) is available for analysis of urine fentanyl. With the rise in fentanyl abuse in the United States, we evaluated the analytical performance of the RDTD test strip compared to mass spectrometry and 2 urine fentanyl immunoassays. METHODS: Leftover, deidentified urine samples collected from inpatients and outpatients from our psychiatric hospital and other clinics were frozen at <-70°C, thawed at room temperature, and centrifuged. Aliquots were tested with the RDTD (CLIA Waived, Inc.) test strips and 2 urine fentanyl immunoassays: the ARK Fentanyl II assay (ARK Diagnostics Inc.) and the Immunalysis SEFRIA Fentanyl assay (Immunalysis Corporation). Both assays were conducted on the Abbott Alinity c chemistry analyzer (Abbott Laboratories). Mass spectrometry analysis was performed at ARUP Laboratories. All assays had a 1 ng/mL positive cutoff. RESULTS: A total of 142 urine samples included 70 positive and 72 negative samples. The RDTD strips had lower sensitivity (84.3%) and efficiency (85.9%) and showed a specificity of 87.5% compared to the other assays. The ARK Fentanyl II assay showed identical sensitivity (95.7%) to the Immunalysis SEFRIA Fentanyl assay but had higher specificity (94.4% vs 81.9%) and overall efficiency (95.1% vs 88.7%). CONCLUSIONS: Differences were noted in the number of false negatives and positives among the assays. The RDTD demonstrated acceptable performance in detecting urine fentanyl in our patient population and would provide faster test results at point-of-care testing sites in our healthcare enterprise.

Implementing Individualized quality control plans and managing risk at the point-of-care for molecular diagnostics.

INTRODUCTION: Faster turnaround times can lead to rapid patient treatment. Implementing a point-of-care (POC) molecular COVID-19 test requires careful planning. In the POC setting, there are numerous operators and regular monitoring of their activities is key to the successful implementation of a POC molecular test. Test errors can arise from samples, operators, reagents, the testing system, and even from the environment. These sources of error should be considered when implementing a new test. AREAS COVERED: We outline the importance of establishing well-defined policies for staff to follow at the preanalytic, analytic and postanalytic phases of SARS-CoV-2 testing. As these factors are crucial for the accuracy and reliability of the test results. The key discussion points are from the CLSI EP23-Ed2 document on developing individualized quality control plans and medical literature search engines such as EMBASE, MEDLINE and MedlinePlus. EXPERT OPINION: The risk management principles applied when implementing nucleic acid POC tests can identify specific control processes to help mitigate common sources of error when conducting molecular testing at the POC.

Functionalized resorcinarenes effectively disrupt the aggregation of αA66-80 crystallin peptide related to cataracts.

Cataracts, an eye lens clouding disease, are debilitating and while operable, remain without a cure. αA66-80 crystallin peptide abundant in cataracted eye lenses contributes to aggregation of αA-crystallin protein leading to cataracts. Inspired by the versatility of macrocycles and programmable guest selectivity through discrete functionalizations, we report on three water-soluble ionic resorcinarene receptors (A, B, and C) that disrupt the aggregation of αA66-80 crystallin peptide. A and B each possess four anionic sulfonate groups, while C includes four cationic ammonium groups with four flexible extended benzyl groups. Through multiple non-covalent attractions, these receptors successfully disrupt and reverse the aggregation of αA66-80 crystallin peptide, which was studied through spectroscopic, spectrometric, calorimetric, and imaging techniques. The αA66-80·receptor complexes were also explored using molecular dynamics simulation, and binding energies were calculated. Even though each of the three receptors can bind with the peptide, receptor C was characterized by the highest binding energy and affinity for three different domains of the peptide. In effect, the most efficient inhibitor was a cationic receptor C via extended aromatic interactions. These results highlight the potential of versatile and tunable functionalized resorcinarenes as potential therapeutics to reverse the aggregation of α-crystallin dominant in eye cataracts.

A dip-and-read optical aptasensor for detection of tau protein.

Neurodegeneration currently remains without a differential diagnosis or cure. Tau protein is one of the biomarkers of neurodegenerative diseases commonly known as tauopathies. Tau protein plays an integral role in stabilizing microtubules and cell structure; however, due to post-translational modifications, tau protein undergoes self-assembly into cytotoxic structures and is co-localized intra- and extracellularly. Hence, tau protein is a viable biomarker associated with protein pathogenesis and neurodegeneration. The novel optical biosensor for tau441 protein is based on the aptamer recognition probe and the biolayer interferometry (BLI) method for detection. The current biotin-aptasensor in combination with the streptavidin surface provides real-time monitoring of tau441 protein in the nanomolar range, with the limit of detection at 6.7 nM in vitro. The tau441 detection is achieved with high selectivity over other neurodegeneration biomarkers which include amyloid-ß and α-synuclein. The aptasensor also allows for tau441 protein detection in a complex matrix such as fetal bovine serum, indicating its utility in other biological fluids for diagnostic applications. The optical method is simple, rapid and highly selective for point-of-care application which is critical for achieving the early and differential diagnosis of neurodegenerative diseases and identifying their treatments. Graphical abstract.