Effect of a barrier on spatial distribution of respiratory particles in a room

Barriers have been widely used to mitigate transmission of Covid-19 and other diseases. Their efficacy for aerosol particles is not well established. The objective of this study was to quantify the impact of a barrier on the spatial distribution of particles released by speaking in a room with a low air-change rate (0.6 +/- 0.2 h-1). The source was a nebulizer that released fluorescent microspheres of diameters 0.5, 1, 6, 10, or 20 microm for 20 min, and the room was outfitted with 108 passive sampling sites. We counted the number of microspheres deposited on slides at sampling locations after >1 h. The presence of a barrier 0.46 m in front of the source resulted in an increase in 0.5 microm particles deposited on the source-side of the barrier and an increase in 0.5 microm particles around the sides of the barrier laterally and at certain locations 4-6 m from the source. The barrier had a minor effect on the distribution of 1 microm particles. There was no observable effect of the barrier on the distribution of 6, 10, and 20 microm particles. Most 10 and 20 microm particles deposited within 0.3 m of the source, although some were found at locations >3 m from the source. These results indicate that barriers may not serve as adequate protection to others in the room, depending on their location relative to the barrier and the exposure timescale. A limitation is that our study utilized only one barrier configuration at one air-change rate.Copyright © 2023 The Author(s). Published with license by Taylor & Francis Group, LLC.

Assessment of different laboratory tests for the diagnosis of novel coronavirus infections

Rapid diagnosis of coronavirus disease 2019 (COVID-19)-infected patients is urgent in making decisions on public health measures. There are different types of diagnostic tests, such as quantitative PCR assay, antibody, and antigen-based and CRISPR-based tests, which detect genetic materials, viral proteins, or human antibodies in clinical samples. However, the proper test should be highly sensitive, quick, and affordable to address this life-threatening situation. This review article highlights the advantages and disadvantages of each test and compares its different features, such as sensitivity, specificity, and limit of detection to reach a reliable conclusion. Moreover, the FDA- authorized kits and studies' approaches toward these have been compared to provide a better perspective to the researchers.Copyright © 2022 Lippincott Williams and Wilkins. All rights reserved.

Impact of temperature on optical sensing in biology based on investigation of SARS-CoV-2.

In this paper, we present an investigation of the influence of the temperature on the sensing of biological samples. We used biofunctionalized microsphere-based fiber-optic sensor to detect immunoglobulin G attached to the sensor head at temperatures relevant in biological research: 5°C, 25°C, and 55°C. The construction of the sensor allowed us to perform measurements in the small amount of solution. The results of our experiment confirm substantial changes in the measured reflected optical power, indicating the need to control the temperature during such measurements. The sensitivity of the sensor used in this research is 8.82 nW/°C. Coefficient R was also calculated and it equals 0.998, which shows good fit between theoretical linear fit and obtained measured data.

Therapeutic delivery: industry update covering January 2022

This industry update covers the period from January 1 through January 31, 2022, and is based on information sourced from company press releases, scientific literature, patents and news websites. January 2022 saw Janssen and Midatech expand their collaboration on bioresorbable polymer microsphere technology for drug delivery. Takeda announced its plans to acquire UK-based Adaptate Biotherapeutics and Gandeeva raised further investment funds to support its drug discovery and development platform focused on the evaluation of protein-drug interactions. Biogen announced that it will sell its stake in a biosimilars joint venture and ABL Bio and Sanofi announced a collaboration around a novel treatment for Parkinson's disease. New regulatory announcements this month included US FDA approvals of a new insomnia treatment for Idorsia and a treatment for atopic dermatitis developed by Pfizer. Insulet gained FDA clearance for a closed-loop insulin pump and Ascendis Pharma followed up its United States approval last year for a once-weekly treatment for growth hormone deficiency with European approval. Pfizer and Ionis announced the discontinuation of the clinical development of a novel cardiovascular drug. In terms of collaborations, Novartis and Alnylam announced they will work together to explore targeted therapies to restore liver function;Scorpion Therapeutics partnered with AstraZeneca to develop novel cancer treatments and Nutriband Inc. and Kindeva Drug Delivery will work together to develop a transdermal fentanyl patch. Collaborations were also announced between Century Therapeutics and Bristol Myers Squibb and Lilly and Entos Pharmaceuticals in the areas of stem cell therapies for cancer treatment and neurology, respectively. A team from the Massachusetts Institute of Technology reported progress in developing oral mRNA treatments and West Pharmaceutical Services published a blog describing the development of a proof-of-principle system for a closed-loop feedback system targeting opioid overdose. A report on the BBC website highlighted the benefits of more sustainable inhalers.

COMPARISON of SARS-CoV-2 LIVE VIRUS NEUTRALIZATION and SEROLOGIC IMMUNOASSAYS

Background: Live virus micro-neutralization (MN) is the gold standard for quantifying the neutralizing titer (NT) of antibodies to SARS-CoV-2. However, performing MN is labor intensive and requires a biosafety level 3 laboratory. We assessed the performance of 8 immunoassays which measure SARS-CoV-2 NT and compared them to gold standard MN results. Methods: Samples from 269 individuals known to previously be SARS-CoV-2 PCR+ (i.e., convalescent individuals, <10% hospitalized) and 200 pre-pandemic individuals were evaluated on 3 lateral flow immunoassays (LFAs;Wondfo Colloidal Gold, Wondfo Colored Microsphere, Wondfo Finecare) and 5 enzyme-linked immunoassays (ELISAs;ImmunoRank, GenScript, Cusabio, Euroimmun NeutraLISA, Euroimmun QuantiVac). MN was performed on all samples from convalescent individuals;results were classified as undetectable vs any detection of MN NT (NT<20 vs. NT>20), as well as high and low MN NT (NT>80 vs. NT<80). Receiver operating curve analysis was used to assess accuracy for detecting levels of NT. The area under the curve (AUC) was calculated for the manufacturer's cut off and empirically to identify the best discriminatory cut off value. Cohen's kappa statistics were calculated to assess categorical agreement and Spearman's rank statistics were calculated to assess correlations. Results: Of the 269 convalescent plasma samples, 89 (33%) had MN NT values <20 (undetectable) and 117 (43%) >80 (high NT). Using the manufacturer's cutoffs, sensitivity for detection of samples with any NT ranged from 79% to 100%, and the false-positive rate (ie, classifying samples with undetectable NT as positive) was highest for LFAs (72% to 84%) and ranged from 14% to 69% for the ELISAs. For all assays except the ImmunoRank and NeutraLISA ELISAs, discrimination to identify samples with any NT was improved by raising the cut off values (Table). AUCs of ∼0.94 to discriminate high NT samples could be achieved for all quantifiable assays using an adjusted cut off value. Cohen's kappa statistic ranged from 0.20 to 0.69. Spearman's rank correlation between each assay and NT value ranged from 0.73 to 0.86. Using the manufacturer's cutoffs, specificity on pre-pandemic samples was ≥98% for all assays except for Cusabio which was 86%. Conclusion: The performance of immunoassays using manufacturer's cutoff to discriminate samples with any NT was accurate (AUC>0.83 for all assays), but could be improved by changing the cutoff. Identifying samples with high NT could be achieved using an alternative cutoff.

Teaching a graduate aourse in pharmaceutical excipients: personal experience and perspectives

Excipients are critically important in converting active pharmaceutical ingredients (API) into drug products that have optimal stability, bioavailability, manufacturability, duration of action, and therapeutic benefits. They will play even greater roles in the future to enable drug targeting, delivery of biotech products and vaccines, gene therapy, continuous manufacturing, 3D printing, and so forth. This commentary describes the author’s experience in teaching a graduate course on excipients at St. John’s University to train students on optimal selection and appropriate use of excipients in formulating dosage forms and development of drug delivery systems. The course is offered in 15 two-hour sessions over a semester, and the course materials are divided into 13 modules on chemistry of different classes of polymeric and non-polymeric excipients and their application in dosage form development, including the use as solubilizing agents, lyophilizing agents, cryoprotectants, buffers, biodegradable materials, and carriers for amorphous solid dispersions and 3D printing. The development of coprocessed excipients, the need for new excipients, and the regulatory aspects of excipients are also covered. The course includes presentations by guest speakers from the industry, and the students also watch virtual presentations from experts that are publicly available from the internet. It is a popular course at St. John’s University taken by all graduate students in the pharmaceutics program. It is recommended that such courses are introduced in other pharmacy schools and academic institutions. The course may be adapted to meet specific needs of different academic programs. Professional associations, such as AAPS and CRS, industry groups like IPEC, and the pharmaceutical industry may be able to help in introducing such courses by providing lecture materials and guest lecturers.

Simultaneous Measurement of IgM and IgG Antibodies to SARS-CoV-2 Spike, RBD, and Nucleocapsid Multiplexed in a Single Assay on the xMAP INTELLIFLEX DR-SE Flow Analyzer.

The multiplex capabilities of the new xMAP INTELLIFLEX DR-SE flow analyzer were explored by modifying a serological assay previously used to characterize the IgG antibody to infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The goal was to examine the instrument's performance and to simultaneously measure IgM and IgG antibody responses against multiple SARS-CoV-2 antigens in a single assay. Specific antibodies against the SARS-CoV-2 spike (S), receptor binding domain (RBD), and nucleocapsid (N) proteins were investigated in 310 symptomatic case patients using a fluorescent microsphere immunoassay and simultaneous detection of IgM and IgG. Neutralization potential was studied using the addition of soluble angiotensin-converting enzyme 2 (ACE2) to block antibody binding. A profile extending to 180 days from symptom onset (DFSO) was described for antibodies specific to each viral antigen. Generally, IgM levels peaked and declined rapidly ∼3-4 weeks following infection, whereas S- and RBD-specific IgG plateaued at 80 DFSO. ACE2 more effectively prevented IgM and IgG binding in convalescent cases > 30 DFSO, suggesting those antibodies had greater neutralization potential. This work highlighted the multiplex and multi-analyte potential of the xMAP INTELLIFLEX DR-SE, and provided further evidence for antigen-specific IgM and IgG trajectories in acute and convalescent cases. IMPORTANCE The xMAP INTELLIFLEX DR-SE enabled simultaneous and semi-quantitative detection of both IgM and IgG to three different SARS-CoV-2 antigens in a single assay. The assay format is advantageous for rapid and medium-throughput profiling using a small volume of specimen. The xMAP INTELLIFLEX DR-SE technology demonstrated the potential to include numerous SARS-CoV-2 antigens; future work could incorporate multiple spike protein variants in a single assay. This could be an important feature for assessing the serological response to emerging variants of SARS-CoV-2.

Early Circulation of SARS-CoV-2, Congo, 2020.

To determine when severe acute respiratory syndrome coronavirus 2 arrived in Congo, we retrospectively antibody tested 937 blood samples collected during September 2019-February 2020. Seropositivity significantly increased from 1% in December 2019 to 5.3% in February 2020, before the first officially reported case in March 2020, suggesting unexpected early virus circulation.

First Evidence of Natural SARS-CoV-2 Infection in Domestic Rabbits.

We tested 144 pet rabbits sampled in France between November 2020 and June 2021 for antibodies to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) by microsphere immunoassay. We reported the first evidence of a natural SARS-CoV-2 infection in rabbits with a low observed seroprevalence between 0.7% and 1.4%.

Risk factors and on-site simulation of environmental transmission of SARS-CoV-2 in the largest wholesale market of Beijing, China.

From June 11, 2020, a surge in new cases of coronavirus disease 2019 (COVID-19) in the largest wholesale market of Beijing, the Xinfadi Market, leading to a second wave of COVID-19 in Beijing, China. Understanding the transmission modes of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and the personal behaviors and environmental factors contributing to viral transmission is of utmost important to curb COVID-19 rise. However, currently these are largely unknown in food markets. To this end, we completed field investigations and on-site simulations in areas with relatively high infection rates of COVID-19 at Xinfadi Market. We found that if goods were tainted or personnel in market was infected, normal transaction behaviors between sellers and customers, daily physiological activities, and marketing activities could lead to viral contamination and spread to the surroundings via fomite, droplet or aerosol routes. Environmental factors such as low temperature and high humidity, poor ventilation, and insufficient hygiene facilities and disinfection practices may contribute to viral transmission in Xinfadi Market. In addition, precautionary control strategies were also proposed to effectively reduce the clustering cases of COVID-19 in large-scale wholesale markets.

A Multiplex Microsphere IgG Assay for SARS-CoV-2 Using ACE2-Mediated Inhibition as a Surrogate for Neutralization.

The coronavirus disease 2019 (COVID-19) pandemic has highlighted the challenges inherent to the serological detection of a novel pathogen such as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Serological tests can be used diagnostically and for surveillance, but their usefulness depends on their throughput, sensitivity, and specificity. Here, we describe a multiplex fluorescent microsphere-based assay, 3Flex, that can detect antibodies to three major SARS-CoV-2 antigens-spike (S) protein, the spike ACE2 receptor-binding domain (RBD), and nucleocapsid (NP). Specificity was assessed using 213 prepandemic samples. Sensitivity was measured and compared to that of the Abbott Architect SARS-CoV-2 IgG assay using serum samples from 125 unique patients equally binned (n = 25) into 5 time intervals (≤5, 6 to 10, 11 to 15, 16 to 20, and ≥21 days from symptom onset). With samples obtained at ≤5 days from symptom onset, the 3Flex assay was more sensitive (48.0% versus 32.0%), but the two assays performed comparably using serum obtained ≥21 days from symptom onset. A larger collection (n = 534) of discarded sera was profiled from patients (n = 140) whose COVID-19 course was characterized through chart review. This revealed the relative rise, peak (S, 23.8; RBD, 23.6; NP, 16.7 [in days from symptom onset]), and decline of the antibody response. Considerable interperson variation was observed with a subset of extensively sampled intensive care unit (ICU) patients. Using soluble ACE2, inhibition of antibody binding was demonstrated for S and RBD, and not for NP. Taking the data together, this study described the performance of an assay built on a flexible and high-throughput serological platform that proved adaptable to the emergence of a novel infectious agent.

A simple screening test of filtration efficiency for protecting the gas sampling line from coronavirus using fluorescent microspheres.

BACKGROUND: During the coronavirus pandemic, preventing contamination of the anesthesia machine, critical to avoid cross-contamination between patients, has proven challenging when treating premature infants and neonates. While attaching a HEPA filter to the endotracheal tube will protect the anesthesia machine and the gas sampling line from contamination, this contribution to the dead space makes ventilation of these small patients challenging. Direct filtration of the gas sampling line eliminates this problem; however, appropriate filters are not readily available. AIMS: Identify a small filter capable of filtering out particles of a size similar to the SARS-CoV-2 virus for the gas sampling line. METHODS: We used fluorescence microspheres suspended in a solution for a challenge test to determine the filtration efficiency of various filters. The microspheres varied in diameter (0.02 µm, 0.042 µm, 0.109 µm, and 0.989 µm). A fluorescence plate reader was used to evaluate the degree of fluorescence intensity in the flow-through from various filters and referenced to the fluorescence intensity of the input. RESULTS: AHEPA filter, as recommended as an anti-viral filter, effectively filtered all the particles tested. The B. Braun PERIFIX Flat Epidural Filter was the second most effective filter, filtering particles larger than 0.042 µm. Other filters tested did not filter fluorescence microspheres equivalent in size to a single coronavirus particle (0.07 µm). CONCLUSIONS: Although the Food and Drug Administration (FDA) has not approved the Flat Epidural Filter for use as an anesthesia machine gas filter, our simple challenge test suggests that it could be used to effectively filter the anesthesia gas sampling line.

Development of a Sensitive Immunochromatographic Method Using Lanthanide Fluorescent Microsphere for Rapid Serodiagnosis of COVID-19.

The SARS-CoV-2 infection that caused the COVID-19 pandemic quickly spread worldwide within two months. Rapid diagnosis of the disease and isolation of patients are effective ways to prevent and control the spread of COVID-19. Therefore, a sensitive immunofluorescent assay method was developed for rapid detection of special IgM and IgG of COVID-19 in human serum within 10 min. The recombinant nucleocapsid protein of 2019 novel coronavirus was used as capture antigen. Lanthanide, Eu(III) fluorescent microsphere, was used to qualitatively/semiquantitatively determine the solid phase immunochromatographic assay. A total of 28 clinical positive and 77 negative serum or plasma samples were included in the test. Based on the analysis of serum or plasma from COVID-19 patients and healthy people, the sensitivity and specificity of the immunochromatographic assay were calculated as 98.72% and 100% (IgG), and 98.68% and 93.10% (IgM), respectively. The results demonstrated that rapid immunoassay has high sensitivity and specificity and was useful for rapid serodiagnosis of COVID-19.

From micro to nano: evolution and impact of drug delivery in treating disease.

Over the past 50 years, drug delivery breakthroughs have enabled the approval of several important medicines. Often, this path starts with innovation from academic collaborations amongst biologists, chemists, and engineers, followed by the formation of a start-up company driving clinical translation and approval. An early wave featured injectable (i.e., intramuscular, subcutaneous) biodegradable polymeric microspheres to control drug release profiles for peptides and small molecules (e.g., Lupron Depot®, Risperdal Consta®). With these early successes for microspheres, research shifted to exploring systemic delivery by intravenous injection, which required smaller particle sizes and modified surface properties (e.g., PEGylation) to enable long circulation times. These new innovations resulted in the nanoparticle medicines Doxil® and Abraxane®, designed to improve the therapeutic index of cytotoxic cancer agents by decreasing systemic exposure and delivering more drug to tumors. Very recently, the first siRNA lipid nanoparticle medicine, Patisiran (Onpattro®), was approved for treating hereditary transthyretin-mediated amyloidosis. In this inspirational note, we will highlight the technological evolution of drug delivery from micro- to nano-, citing some of the approved medicines demonstrating the significant impact of the drug delivery field in treating many diseases.