Recent progress in online detection methods of bioaerosols

The aerosol transmission of coronavirus disease in 2019, along with the spread of other respiratory diseases, caused significant loss of life and property;it impressed upon us the importance of real-time bioaerosol detection. The complexity, diversity, and large spatiotemporal variability of bioaerosols and their external/internal mixing with abiotic components pose challenges for effective online bioaerosol monitoring. Traditional methods focus on directly capturing bioaerosols before subsequent time-consuming laboratory analysis such as culture-based methods, preventing the high-resolution time-based characteristics necessary for an online approach. Through a comprehensive literature assessment, this review highlights and discusses the most commonly used real-time bioaerosol monitoring techniques and the associated commercially available monitors. Methods applied in online bioaerosol monitoring, including adenosine triphosphate bioluminescence, laser/light-induced fluorescence spectroscopy, Raman spectroscopy, and bioaerosol mass spectrometry are summarized. The working principles, characteristics, sensitivities, and efficiencies of these real-time detection methods are compared to understand their responses to known particle types and to contrast their differences. Approaches developed to analyze the substantial data sets obtained by these instruments and to overcome the limitations of current real-time bioaerosol monitoring technologies are also introduced. Finally, an outlook is proposed for future instrumentation indicating a need for highly revolutionized bioaerosol detection technologies.

SARS-CoV-2 VARIANTS-DEPENDENT INFLAMMASOME ACTIVATION

Background: Innate immunity is the first line of defense in response to pathogens, which acts locally and also leads the stimulation of adaptive immunity through at least with IL-1beta secretion. It has been shown that SARSCoV- 2 infection triggered the NLRP-3 inflammasome activation and the IL-1beta secretion. The aim of this study was to analyze and compare the level of IL-1beta secretion that is one of the most important innate immunity cytokines, in monocyte-like cells infected with 6 different variants of the SARS-CoV-2. Method(s): Six SARS-CoV-2 variants (historical (B.1, D614G), Alpha, Beta, Gamma, Delta and Omicron BA.1) were isolated from COVID-19 hospitalized patients. Viral stocks were obtained by inoculation in Vero and Vero-TRMPSS2 cells. THP-1 monocyte-like cells were cultured with RPMI-hepes 10% FBS-0.05 mM 2-mercaptoethanol. A total of 5 x 104 of THP-1 cells was plated per well in 96-wells plate and differentiated with 10nM of PMA for 24h. Differenciated- THP-1 were first primed with LPS 1mug/ml for 2h and infected with different SARS-CoV-2 variants with a MOI 0.1. IL-1beta was measured by luminescence in the supernatant after 24 h of infection. Result(s): We analyzed and compared IL-1beta secretion between SARS-CoV-2 virus 6 sublineages after infection of monocytes like THP-1. We observed that THP-1 cells infected with SARS-CoV-2 variants presented a significantly higher IL-1beta secretion than non-infected cells. Moreover, some SARS-CoV-2 variants led to a stronger IL-1beta secretion, and particularly we observed a significantly higher level of IL-1beta cells infected with Omicron BA.1 sublineage compared to other variants. Indeed, Omicron BA.1 infected cells presented the higher IL-1beta secretion (median 385.7 pg/ml IQR[302.6-426.3]) follows by the Delta variants and the historical variants (median 303.6 [266.3-391.9] and 281.9 [207.2-410], respectively). Alpha, Beta and Gamma variants presented the lowest IL-1beta secretion (median 228.1 [192.5-276.4], 219.1 [185.1-354.2] and 211 [149.8- 228.8]). Conclusion(s): We observed the inflammasome activation for the 6 SARS-CoV-2 sublineages with a variation in level of IL-1beta secretion. Indeed, our results suggested that Omicron BA.1 was more recognized by the innate immune cells than other SARS-CoV-2, which could in part, with its upper respiratory tract tropism, possibly explain its less clinical virulence. Taking together, these results suggest that the innate immunity response and precisely, IL-1beta secretion pathways were activated in a SARS-CoV-2 variants-dependent manner.

Quantification of functional antibody titers in a mouse model of SARS-CoV-2 infection

Towards the end of 2019 a novel severe acute respiratory syndrome (SARS)-like coronavirus (SARS-CoV-2) caused the ongoing global pandemic. The virus surface consists of spike proteins that mediate SARS-CoV-2 entry into cells through its receptor-binding domain (RBD) that attaches to the human receptor Angiotensin- Converting Enzyme 2 (ACE2). Upon infection with foreign material, like viruses and bacteria, the human immune system responds by producing a humoral response specific to the viral antigen. Cells from the innate immune system and antibodies generated in the humoral response work to destroy and block infectious antigens from causing damage to the human cells. The S protein of SARSCoV- 2 is the key protein that stimulates the immune system to generate neutralizing antibodies. To safely test and investigate SARS-CoV-2 in BSL-2 lab setting, we propagated a surrogate pseudo typed virus to evaluate the ability of antibodies to reduce viral cell entry and replication in SARS-CoV-2 infected mice model. Quantifying the functional ability of neutralizing antibodies would help us understand how they influence reinfection in recovered individuals. We hypothesize that antibodies generated in SARS-CoV-2 infected mice models will induce a protective immune response against the SARSCoV- 2 infection. To detect and quantify the protective immune response generated in mice, we performed two different serological assays and identified antibodies endpoint titers. Mice were infected with Delta and Beta at time points Day 3 and Day 4. We performed a SARS-CoV-2 Spike pseudo virus neutralization assay and measured luminescence to determine the percentage neutralization of functional antibodies induced in mice serum samples upon infection. Utilizing indirect ELISAs,' we measured absorbance for IgA antibodies in Bronchoalveolar lavage fluid (BALF) serum and total IgG antibodies in cardiac bleeds. Our results showed we did not obtain neutralizing activity of antibodies in mice serum samples taken at early time points, 24 hrs and 4 days, after infection with the Delta variant of SARS CoV2 virus using both the pseudo viruses Omicron andWA spike.We obtained 100% neutralizing activity in mice serum samples taken at day 21 and infected with Beta variant of SARS CoV2 virus using both the pseudo viruses Omicron and WA spike demonstrating that there is cross-neutralization against various variants of concern. Antibodies (IgA, IgM, IgG) generated in mice 3 weeks post infection with SARS CoV2 (Beta) virus are capable of neutralizing and inhibiting the entry of WA spike and Omicron pseudo viruses in human HEK293 T Ace2 cells. Moving forward utilizing samples with timepoints surpassing 3 weeks could possibly yield higher concentrations of IgA and IgM antibodies that can neutralize the SARS-CoV-2 pseudo virus. Thank you to Dr. Rhea Coler, the entire Coler lab, National Institutes of Health (NIH), and Seattle Children's Research Institute.Copyright © 2023 The American Society for Biochemistry and Molecular Biology, Inc.

Using Synthetic Biology methods to construct a functional estrogen biosensor based on split Nanoluciferase activity

The presence of estrogenic compounds (endocrine-disruptors, EDCs) in the water supply raises concerns about human and aquatic health. Current methods for detecting estrogen contamination require expensive, time-consuming techniques such as liquid chromatography-mass spectrometry and high-performance liquid chromatography. Previously reported estrogen biosensors required multiple cloning and transformation steps for successful detection in bacteria. Synthetic biology allows for the construction of genetic devises composed of DNA sequences modified to be interchangeable and provide novel functions. New tools and devices are constantly needed to enhance the already extensive list of novel genetic parts. Our approach to the design of an estrogen responsive element uses methodology developed in the Wells lab (Elledge et al, 2021) to detect SARS-CoV-2 antibodies. This methodology takes advantage of the split Nanoluciferase (spLUC) protein divided into two functional domains (designated SmBit and LgBit). Based on rational engineering design we express dimerization dependent LgBit and SmBit fused to the Estrogen Receptor alpha protein (ERalpha) in bacteria cells. These two monomeric proteins will dimerize in the presence of estrogen, reconstitute the split luciferase enzyme and reestablish enzyme activity. Cells can be lysed, and luminescence detected to quantify estrogen present in the sample. We present here the construction strategy and proof of concept data demonstrating the efficiency of this dual-functional biosensor and its effectiveness for detection of estrogenic compounds in contaminated water. NSF-REU-1852150, REU Site: A multisite REU in Synthetic Biology, 2019.Copyright © 2023 The American Society for Biochemistry and Molecular Biology, Inc.

Customized Luminescent Multiplexed Quick-Response Codes as Reliable Temperature Mobile Optical Sensors for eHealth and Internet of Things

The need to sense and track in real time through sustainable and multifunctional labels is exacerbated by the COVID-19 pandemic, where the simultaneous measurement of body temperature and the fast tracking of people is required. One of the big challenges is to develop effective low-cost systems that can promote healthcare provision everywhere and for that, smarter and personalized Internet of things (IoT) devices are a pathway in large exploration, toward cost reduction and sustainability. Using the concept of color-multiplexed quick response (QR) codes, customized smart labels formed by two independent layers and smart location patterns provide simultaneous tracking and multiple synchronous temperature reading with maximum sensitivity values of 8.5% K-1 in the physiological temperature range, overwhelming the state-of-the-art optical sensor for healthcare services provided electronically via the internet (eHealth) and mobile sensors (mHealth).

Recent advancements of metal-organic frameworks in sensing platforms: relevance in the welfare of the environment and the medical sciences with regard to cancer and SARS-CoV-2

Supramolecular architectures decorated with various conjugated building blocks give rise to numerous luminescent frameworks with interesting chemical and photophysical properties. The luminescence properties of these MOFs help global researchers achieve success in the field of recognition applications of MOFs for the detection of various targeted toxic analytes. In this regard, different MOF-based materials, along with their different host-guest recognition strategies, have been developed, emphasising selective and sensitive natures towards a particular analyte, which indeed helps in protecting our environment. The present review article discusses state-of-the art progress based on (i) advancement of electrochemical MOF-based sensors, (ii) detection of various waterborne pollutants & VOCs, and (iii) recent progress of MOFs in biomedical sciences, with regard to cancer & SARS-CoV-2, along with the advantages and current challenges to combat SARS-CoV-2 for the clinical purposes. Herein, detection of particular analytes along with their interactive mechanisms have been precisely described;however, it needs to be noted that detailed host-guest mechanistic revelations is not the topic of discussion in the present exploration. In this review, we have covered almost the last 14 years (2008-2022) of research on MOFs in the various sensing platforms. In a nutshell, the luminescent MOFs, along with their extraordinary applicability in the domains of chemical, biomedical and environmental arenas as welfare tools, have been studied in the present review article. © 2023 The Royal Society of Chemistry.

Development of an Interactive Touchless Technology Based on Static-Electricity-Induced Luminescence.

Touchless technology has garnered significant interest in recent years because of its effectiveness in combating infectious diseases such as the novel coronavirus (COVID-19). The goal of this study was to develop an inexpensive and high-precision touchless technology. A base substrate was coated with a luminescent material that emitted static-electricity-induced luminescence (SEL), and it was applied at high voltage. An inexpensive web camera was used to verify the relationship between the non-contact distance to a needle and the applied-voltage-triggered luminescence. The SEL was emitted at 20-200 mm from the luminescent device upon voltage application, and the web camera detected the SEL position with an accuracy of less than 1 mm. We used this developed touchless technology to demonstrate a highly accurate real-time detection of the position of a human finger based on SEL.

Detection of COVID-19 DNA using Förster Resonance Energy Transfer between upconversion and gold nanoparticles

FRET is ascribed to the spectral overlapping of upconversion luminescence and the absorption of AuNPs. This experiment enables early-stage coronavirus detection. The results show a sensitivity of 100 fM for the detection of COVID-19 DNA. © 2022 The Author(s)

Rapid point-of-care detection of SARS-CoV-2 RNA with smartphone-based upconversion luminescence diagnostics.

Accurate COVID-19 screening via molecular technologies is still hampered by bulky instrumentation, complicated procedure, high cost, lengthy testing time, and the need for specialized personnel. Herein, we develop point-of-care upconversion luminescence diagnostics (PULD), and a streamlined smartphone-based portable platform facilitated by a ready-to-use assay for rapid SARS-CoV-2 nucleocapsid (N) gene testing. With the complementary oligo-modified upconversion nanoprobes and gold nanoprobes specifically hybridized with the target N gene, the luminescence resonance energy transfer effect leads to a quenching of fluorescence intensity that can be detected by the easy-to-use diagnostic system. A remarkable detection limit of 11.46 fM is achieved in this diagnostic platform without the need of target amplification, demonstrating high sensitivity and signal-to-noise ratio of the assay. The capability of the developed PULD is further assessed by probing 9 RT-qPCR-validated SARS-CoV-2 variant clinical samples (B.1.1.529/Omicron) within 20 min, producing reliable diagnostic results consistent with those obtained from a standard fluorescence spectrometer. Importantly, PULD is capable of identifying the positive COVID-19 samples with superior sensitivity and specificity, making it a promising front-line tool for rapid, high-throughput screening and infection control of COVID-19 or other infectious diseases.

Detection of COVID-19 DNA using Förster Resonance Energy Transfer between upconversion and gold nanoparticles

FRET is ascribed to the spectral overlapping of upconversion luminescence and the absorption of AuNPs. This experiment enables early-stage coronavirus detection. The results show a sensitivity of 100 fM for the detection of COVID-19 DNA. © 2022 The Author(s)

The Luminescence Hypothesis of Olfaction.

A new hypothesis for the mechanism of olfaction is presented. It begins with an odorant molecule binding to an olfactory receptor. This is followed by the quantum biology event of inelastic electron tunneling as has been suggested with both the vibration and swipe card theories. It is novel in that it is not concerned with the possible effects of the tunneled electrons as has been discussed with the previous theories. Instead, the high energy state of the odorant molecule in the receptor following inelastic electron tunneling is considered. The hypothesis is that, as the high energy state decays, there is fluorescence luminescence with radiative emission of multiple photons. These photons pass through the supporting sustentacular cells and activate a set of olfactory neurons in near-simultaneous timing, which provides the temporal basis for the brain to interpret the required complex combinatorial coding as an odor. The Luminescence Hypothesis of Olfaction is the first to present the necessity of or mechanism for a 1:3 correspondence of odorant molecule to olfactory nerve activations. The mechanism provides for a consistent and reproducible time-based activation of sets of olfactory nerves correlated to an odor. The hypothesis has a biological precedent: an energy feasibility assessment is included, explaining the anosmia seen with COVID-19, and can be confirmed with existing laboratory techniques.

Expression of exogenous proteins in donor platelets treated with lipid nanoparticles encapsulating mRNA

Background: Platelets are transfused therapeutically for hemostasis, and are an integral part of hemorrhage management. However, transfusions can be ineffective in the most severe cases of hemorrhage. Platelets are also a potential cell therapy in other applications, but development has been hindered by inadequate methods to control which proteins are expressed by platelets. Currently, there are no methods to express exogenous proteins in transfusable platelets, which would expand their use to help treat the diseases they modulate. A method is therefore needed to modify transfusable platelets, and thus enhance their protein composition for specific applications. Aim(s): To produce engineered, transfusable platelets to enhance their natural coagulability and functional repertoire by directly transfecting donor-derived platelets with mRNA via lipid nanoparticle (LNP)-mediated delivery. The recent advances through the COVID-19 mRNA vaccines demonstrates the clinical safety and efficacy of LNP-mediated gene therapy, and thus offers a promising strategy to effectively engineer modified platelets. Method(s): Donor-derived platelets were washed and subsequently incubated with a systematic array of LNPs encapsulating Cy5-labeled mRNA encoding for nanoluciferase in comparison to commercial transfection reagents. LNP uptake and platelet activation via CD62p levels was assessed following 4 hours by flow cytometry, while luciferase expression was assessed by normalizing the luminescence intensity to the total protein content. Result(s): Platelets took up the mRNA through all conditions tested;nanoluciferase was only expressed, however, in platelets treated with LNPs and not commercial reagents. Systematically optimizing LNPs increased nanoluciferase expression nine-fold relative to pre-optimized LNPs. Exogenous protein expression did not appear to correlate with mRNA uptake nor platelet activation. Conclusion(s): Platelets transfected with LNPs can express exogenous protein. Further optimization can eventually lead to the creation of a platform technology that in the long-term will allow platelets to deliver therapeutic proteins and yield more effective platelet products.

Alternative Methods to Detect Severe Acute Respiratory Syndrome Coronavirus 2 Antibodies.

The COVID-19 pandemic has resulted in the development, validation, and rapid adoption of multiple novel diagnostic approaches. Hundreds of SARS-CoV-2 serologic assays have been developed and deployed to contain the spread of the virus, and to supply timely and important health information. Most of these serologic assays were based on a conventional enzyme-linked immunosorbent assay or the lateral flow assay format. The immunoassays that were developed were based on alternative technologies and are highlighted in this article with a brief discussion of the assay principle and the pros and cons for each assay. Measurement of neutralizing antibodies is also discussed.

Merging microfluidics with luminescence immunoassays for urgent point-of-care diagnostics of COVID-19.

The Coronavirus disease 2019 (COVID-19) outbreak has urged the establishment of a global-wide rapid diagnostic system. Current widely-used tests for COVID-19 include nucleic acid assays, immunoassays, and radiological imaging. Immunoassays play an irreplaceable role in rapidly diagnosing COVID-19 and monitoring the patients for the assessment of their severity, risks of the immune storm, and prediction of treatment outcomes. Despite of the enormous needs for immunoassays, the widespread use of traditional immunoassay platforms is still limited by high cost and low automation, which are currently not suitable for point-of-care tests (POCTs). Microfluidic chips with the features of low consumption, high throughput, and integration, provide the potential to enable immunoassays for POCTs, especially in remote areas. Meanwhile, luminescence detection can be merged with immunoassays on microfluidic platforms for their good performance in quantification, sensitivity, and specificity. This review introduces both homogenous and heterogenous luminescence immunoassays with various microfluidic platforms. We also summarize the strengths and weaknesses of the categorized methods, highlighting their recent typical progress. Additionally, different microfluidic platforms are described for comparison. The latest advances in combining luminescence immunoassays with microfluidic platforms for POCTs of COVID-19 are further explained with antigens, antibodies, and related cytokines. Finally, challenges and future perspectives were discussed.

Luminescence nanomaterials for biosensing applications.

Due to their capacity to immobilize more bioreceptor parts at reduced volumes, nanomaterials have emerged as potential tools for increasing the sensitivity to specific molecules. Furthermore, carbon nanotubes, gold nanoparticles, polymer nanoparticles, semiconductor quantum dots, nanodiamonds, and graphene are among the nanomaterials that are under investigation. Due to the fast development of this field of research, this review summarizes the classification of biosensors using the main receptors and design of biosensors. Numerous studies have concentrated on the manipulation of persistent luminescence nanoparticles (PLNPs) in biosensing, cell tracking, bioimaging, and cancer therapy due to the effective removal of autofluorescence interference from tissues and the ultra-long near-infrared afterglow emission. As luminescence has a unique optical property, it can be detected without constant external illumination, preventing autofluorescence and light dispersion through tissues. These successes have sparked an increasing interest in creating novel PLNP types with the desired superior properties and multiple applications. In this review, we emphasize the most recent developments in biosensing, imaging, and image-guided therapy whilst summarizing the research on synthesis methods, bioapplications, biomembrane modification, and the biosafety of PLNPs. Finally, the remaining issues and difficulties are examined together with prospective future developments in the biomedical application field.

Quantitative PBMC ADCC bioassay and ADCC reporter bioassays for immunotherapy and SARS-CoV-2 monoclonal antibody development

Fc effector function is one of the main mechanisms of action (MoA) for therapeutic monoclonal antibodies (mAbs). Quantitative measurement of antibody-dependent cellular cytotoxicity (ADCC) is critically required for understanding the Fc function in mAb drug development. Despite the increasing interest and clinical success of the mAb therapeutic, it has been highly challenging to measure their ADCC activity in a reproducible and quantitative manner due to the lack of consistency in current methods that are based on primary PBMCs or NK cells and use tedious assay procedures. To improve ADCC assay precision so they can be validated as potency assay in cGMP laboratories, we developed reporter based ADCC bioassays using engineered effector cell line stably expressing a luciferase reporter and FcγRIIIa (V or F variant) to replace primary PBMC to overcome the assay variation. The ADCC reporter bioassays have been validated according to ICH guidelines by many laboratories and are demonstrated to be suitable for product release and stability studies in a quality-controlled environment. For early research and antibody characterization, we developed an improved PBMC ADCC assay using ADCC-prequalified PBMCs and engineered HiBiT target cells so they can measure the target specific lysis in ADCC. The PBMCs used in the study are isolated from prescreened blood donors and QC tested in ADCC assay. When HiBiT target cells are incubated with an antibody and PBMCs, HiBiT are released to the culture medium where it binds to LgBiT in the detection reagent to form a functional NanoBiT luciferase to generate luminescence signal. This new PBMC ADCC bioassay is simple, homogenous, highly sensitive, and gives a robust assay window. We demonstrate that it can quantitatively measure the potency for mAb drugs in cancer immunotherapy (e.g., rituximab, trastuzumab), and for anti-SARS-CoV-2 spike antibodies in antiviral drug development. Additionally, it shows antibody potency comparable with the ADCC reporter bioassay. In summary, the new PBMC ADCC bioassay using HiBiT target cells can be a valuable tool for early antibody discovery and characterization and also for method bridging study with ADCC reporter bioassay.

Strategies for sensitivity enhancement of point-of-care devices

Point-of-care (POC) technology reduces the time required for diagnosis at a reduced cost to facilitate early treatment, continuous monitoring, and prevention of fatal outcomes. Biosensors are the key to the development of reliable and accurate POC devices as they are capable of detecting clinical biomarkers based on bio-recognition events. Paper-based microfluidics and lateral flow assays (LFAs) are the most commonly used techniques for the development of POC devices. Electrochemical biosensors provide high sensitivity and reproducibility in comparison to optical biosensors. Sensitivity enhancement of POC devices is imperative to lower their detection limit for improved analysis of target biomarkers at low concentrations. In this review, we have discussed the need for sensitivity enhancement in POC devices. Various sensitivity enhancement strategies such as physical, chemical, electrochemical, nanomaterial, nucleic acid, enzymatic, label-based, etc. are discussed along with numerous examples. The role of biosensors in the sensitivity enhancement of POC devices is also described herein. We have illustrated the relationship between sensitivity and the limit of detection of POC devices. Several sensitivity enhancement strategies that have been either adopted or have the potential to be realized for POC devices have been summarized in tabular form. In terms of future perspectives, the sensitivity enhancement of POC devices for the detection of important biomarkers is yet to be comprehended copiously amid the rising market for POC devices.

Modified mRNA delivery to the heart using Lipid Nanoparticles

Myocardial infarction is a global health burden for which there is no treatment available that aims to recover the damaged tissue after the ischemic event. Lipid nanoparticles (LNPs) represent a well characterized class of mRNA delivery systems, which were recently approved for clinical usage in their application for mRNA-based covid-19 vaccines. After myocardial infarction, endogenous mechanisms that enable repair of the functional damaged tissue can be triggered by modified mRNA (modRNA) delivery, locally in the infarcted area. As a first step, in order to optimize the LNP formulation for effective myocardial delivery and study cellular tropism of the LNPs in the heart, different LNPs formulations will be evaluated as delivery systems in a murine healthy heart model. Different LNP formulations varying in type and amount of helper lipid were used as delivery systems for modRNA encoding the reporter genes luciferase or eGFP. In vitro, LNPs were evaluated for modRNA delivery in a human endothelial cell line (HMEC-1), induced pluripotent stem cell-derived cardiomyocytes (iPS-CMs) and induced pluripotent stem cell -derived fibroblasts (iPS-FBs). In vivo, modRNA delivery was evaluated in C57BL-6 mice, undergoing open chest heart surgery under general anaesthesia in order to infuse LNPs into the left ventricular wall. For determination of luciferase expression levels, animals were infused with luciferin substrate intraperitoneally 24 hrs after injection. Heart, liver, lungs, spleen and kidneys were extracted for imaging in a bioluminescence imaging system. The organs were then stored in liquid nitrogen for further ex-vivo modRNA delivery analysis. For determining cellular tropism, histology was performed on mice treated with eGFP modRNA. Both bioluminescence imaging and luminescence analysis in tissue lysates showed that mRNA transfection is achieved in the myocardium 24 hours after LNP intramyocardial administration. However, all LNP formulations also resulted in high expression levels in other organs, including liver and spleen. Changes in type or amount of helper lipid in LNPs strongly affected transfection levels. Histology of the treated hearts revealed a distinct transfection pattern. The targeted, interstitial cells were negative for CD31 (marker for endothelial cells and monocytes) and Troponin I3 (marker for cardiomyocytes) (Figure 1). We show that, using an optimized LNP formulation, a significant degree of modRNA local transfection of the heart can be achieved. However, despite the local route of administration (into the left ventricular wall), the highest LNP transfection is shown in remote organs such as liver and spleen. More improvements of the LNP formulations must be done to increase their tropism towards the heart tissue for their optimization as cardiac delivery systems. Determining which cell types are being targeted is also important in order to establish a therapeutic target when applying the LNPs for cardiac therapy. (Figure Presented).

Study of Mask Fibers for Protection Against SARS-Cov-2 Via Luminescent Aerosolized Silicon Nanoparticles

During the 2020-current COVID-19 pandemic, the importance of wearing a mask to reduce infection and spread is key. The mask works as filter for the different microorganisms. In this work the geometrical part of the filtration process of the N95 and surgical masks was studied using luminescent ultra-small silicon nanoparticles (Si-NPs) to represent the SARS-CoV-2 by spraying it on the mask using atomizer. Scanning electron microscopy (SEM), and optical microscope were used to check the mask. The obtained images show that the Si nanoparticles to are trapped by the PE fiber network, indicating its ability to filter SARS-CoV-2. This visualization using nanotechnology can help to further improve mask designs for better filtration. © 2022 ECS - The Electrochemical Society.

Luminescent Assay for the Screening of SARS-CoV-2 MPro Inhibitors.

Since the outbreak of SARS-CoV-2 in December 2019 millions of infections have been reported globally. The viral chymotrypsin-like main protease (MPro ) exhibits a crucial role in viral replication and represents a relevant target for antiviral drug development. In order to screen potential MPro inhibitors we developed a luminescent assay using a peptide based probe containing a cleavage site specific for MPro . This assay was validated showing IC50 values similar to those reported in the literature for known MPro inhibitors and can be used to screen new inhibitors.