Development of a Bamlanivimab Infusion Process in the Emergency Department for Outpatient COVID-19 Patients.

The coronavirus disease 2019 (COVID-19) pandemic has prompted the creation of new therapies to help fight against the novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Bamlanivimab is a SARS-CoV-2 monoclonal antibody that is administered as an intravenous infusion to ambulatory patients with mild or moderate COVID-19, but a concern that arose was deciding the optimal location for patients to receive the medication. This report describes the development and implementation of a bamlanivimab infusion center in the emergency department of three hospitals in Orange County, California, shortly after bamlanivimab received emergency use authorization. As a result, a total of 601 patients received bamlanivimab in one of these three emergency departments between December 2020 to April 2021. The emergency department was shown to be an optimal setting for administration of bamlanivimab due to its convenience, accessibility, and capabilities for monitoring patients.

An implantable Teflon chip holding lithium naphthalocyanine microcrystals for secure, safe, and repeated measurements of pO2 in tissues.

Lithium naphthalocyanine (LiNc) is a crystalline material that has significant potential as a probe for EPR (electron paramagnetic resonance)-based biological oximetry (Pandian et al. J. Mater. Chem. 19:4138-4147, 2009a). However, implantation of LiNc crystals in tissues in raw or neat form is undesirable since dispersion of crystals in tissue may lead to loss of EPR signal, while also exacerbating biocompatibility concerns due to tissue exposure. To overcome these concerns, we have encapsulated LiNc crystals in an oxygen-permeable polymer, Teflon AF 2400 (TAF). Fabrication of TAF films incorporating LiNc particles (denoted as LiNc:TAF chip) was carried out using solvent-evaporation techniques. The EPR linewidth of LiNc:TAF chip was linearly dependent on oxygen-partial pressure (pO(2)) and did not change significantly relative to neat LiNc crystals. LiNc:TAF chip responded to changes in pO(2) reproducibly, enabling dynamic measurements of oxygenation in real time. The LiNc:TAF chips were stable in tissues for more than 2 months and were capable of providing repeated measurements of tissue oxygenation for extended periods of time. The results demonstrated that the newly fabricated, highly oxygen-sensitive LiNc:TAF chip will enhance the applicability of EPR oximetry for long-term and clinical applications.

Polymer coating of paramagnetic particulates for in vivo oxygen-sensing applications.

Crystalline lithium phthalocyanine (LiPc) can be used to sense oxygen. To enhance biocompatibility/stability of LiPc, we encapsulated LiPc in Teflon AF (TAF), cellulose acetate (CA), and polyvinyl acetate (PVAc) (TAF, previously used to encapsulate LiPc, was a comparator). We identified water-miscible solvents that don't dissolve LiPc crystals, but are solvents for the polymers, and encapsulated crystals by solvent evaporation. Oxygen sensitivity of films was characterized in vitro and in vivo. Encapsulation did not change LiPc oximetry properties in vitro at anoxic conditions or varying partial pressures of oxygen (pO2). EPR linewidth of encapsulated particles was linear with pO2, responding to pO2 changes quickly and reproducibly for dynamic measurements. Encapsulated LiPc was unaffected by biological oxidoreductants, stable in vivo for four weeks. Oximetry, stability and biocompatibility properties of LiPc films were comparable, but both CA and PVAc films are cheaper, and easier to fabricate and handle than TAF films, making them superior.

Fabrication and physical evaluation of a polymer-encapsulated paramagnetic probe for biomedical oximetry.

Lithium octa-n-butoxynaphthalocyanine (LiNc-BuO) is a promising probe for biological electron paramagnetic resonance (EPR) oximetry and is being developed for clinical use. However, clinical applicability of LiNc-BuO may be hindered by potential limitations associated with biocompatibility, biodegradation, and migration of individual crystals in tissue. To overcome these limitations, we have encapsulated LiNc-BuO crystals in polydimethyl siloxane (PDMS), an oxygen-permeable and bioinert polymer, to fabricate conveniently implantable and retrievable oxygen-sensing chips. Encapsulation was performed by a simple cast-molding process, giving appreciable control over size, shape, thickness and spin density of chips. The in vitro oxygen response of the chip was linear, reproducible, and not significantly different from that of unencapsulated crystals. Cast-molding of the structurally-flexible PDMS enabled the fabrication of chips with tailored spin densities, and ensured non-exposure of embedded LiNc-BuO, mitigating potential biocompatibility/toxicological concerns. Our results establish PDMS-encapsulated LiNc-BuO as a promising candidate for further biological evaluation and potential clinical application.

Oxygen sensitivity and biocompatibility of an implantable paramagnetic probe for repeated measurements of tissue oxygenation.

The use of oxygen-sensing water-insoluble paramagnetic probes, such as lithium octa-n-butoxynaphthalocyanine (LiNc-BuO), enables repeated measurements of pO(2) from the same location in tissue by electron paramagnetic resonance (EPR) spectroscopy. In order to facilitate direct in vivo application, and hence eventual clinical applicability, of LiNc-BuO, we encapsulated LiNc-BuO microcrystals in polydimethylsiloxane (PDMS), an oxygen-permeable and bioinert polymer, and developed an implantable chip. In vitro evaluation of the chip, performed under conditions of sterilization, high-energy irradiation, and exposure to cultured cells, revealed that it is biostable and biocompatible. Implantation of the chip in the gastrocnemius muscle tissue of mice showed that it is capable of repeated and real-time measurements of tissue oxygenation for an extended period. Functional evaluation using a murine tumor model established the suitability and applicability of the chip for monitoring tumor oxygenation. This study establishes PDMS-encapsulated LiNc-BuO as a promising choice of probe for clinical EPR oximetry.

Nanoscale adhesion, friction and wear studies of biomolecules on silicon based surfaces.

Protein layers are deployed over the surfaces of microdevices such as biological microelectromechanical systems (bioMEMS) and bioimplants as functional layers that confer specific molecular recognition or binding properties or to facilitate biocompatibility with biological tissue. When a microdevice comes in contact with any exterior environment, like tissues and/or fluids with a variable pH, the biomolecules on its surface may get abraded. Silicon based bioMEMS are an important class of devices. Adhesion, friction and wear properties of biomolecules (e.g., proteins) on silicon based surfaces are therefore important. Adhesion was studied between streptavidin and a thermally grown silica substrate in a phosphate buffered saline (PBS) solution with various pH values as a function of the concentration of biomolecules in the solution. Friction and wear properties of streptavidin (protein) biomolecules coated on silica by direct physical adsorption and a chemical linker method were studied in PBS using the tapping mode atomic force microscopy at a range of free amplitude voltages. Fluorescence microscopy was used to study the detailed wear mechanism of the biomolecules. Based on this study, adhesion, friction and wear mechanisms of biomolecules on silicon based surfaces are discussed.

Recommendations of the National Heart, Lung, and Blood Institute Nanotechnology Working Group.

Recent rapid advances in nanotechnology and nanoscience offer a wealth of new opportunities for diagnosis and therapy of cardiovascular, pulmonary, and hematologic diseases and sleep disorders. To review the challenges and opportunities offered by these nascent fields, the National Heart, Lung, and Blood Institute convened a Working Group on Nanotechnology. Working Group participants discussed the various aspects of nanotechnology and its applications to heart, lung, blood, and sleep (HLBS) diseases. This report summarizes their discussions according to scientific opportunities, perceived needs and barriers, specific disease examples, and recommendations on facilitating research in the field. An overarching recommendation of the Working Group was to focus on translational applications of nanotechnology to solve clinical problems. The Working Group recommended the creation of multidisciplinary research centers capable of developing applications of nanotechnology and nanoscience to HLBS research and medicine. Centers would also disseminate technology, materials, and resources and train new investigators. Individual investigators outside these centers should be encouraged to conduct research on the application of nanotechnology to biological and clinical problems. Pilot programs and developmental research are needed to attract new investigators and to stimulate creative, high-impact research. Finally, encouragement of small businesses to develop nanotechnology-based approaches to clinical problems was considered important.

The molecular analysis of breast cancer utilizing targeted nanoparticle based ultrasound contrast agents.

This study was structured to challenge the hypothesis that nano-sized particulates could be molecularly targeted and bound to the prognostic and predictive HER-2/neu cell membrane receptor to elicit detectable changes in ultrasound response from human breast cancer cells. SKBR-3 human breast cancer cells were enlisted to test the efficacy of the particle conjugation strategy used in this study and ultimately, to provide conclusive remarks regarding the validity of the stated hypothesis. A characterization-mode ultrasound (CMUS) system was used to apply a continuum mechanics based, two-step inversion algorithm to reconstruct the mechanical material properties of four cell/agarose test conditions upon three independent test samples. The four test conditions include: Herceptin conjugated iron oxide nanoparticles bound to cells (HER-con), Herceptin bound to cells (HER), iso-type matched antibody conjugated iron oxide nanoparticles bound to cells (ISO-con), and Cold Flow Buffer mixed with agarose (CFB). The statistical analysis of these ultrasound results supported the ability to differentiate between HER-2/neu positive SKBR-3 cells that have been successfully tagged with Herceptin(R) conjugated iron oxide particles to those that have not demonstrated particle binding. These findings serve as promising proof-of-concept data for the development of a quantitative histopathologic evaluation tool directed towards both in situ and in vivo applications. The ultimate goal of this research is to exploit the molecular expression of the HER-2/neu protein to offer rapid, quantitative ultrasound information concerning the malignancy rating of human breast tissue employing tumor targeting nanoparticle based ultrasound contrast agents. When fully developed, this could potentially help 32,000-63,000 women efficiently find their proper treatment strategy to fight and win their battle against breast cancer.

Morphology and adhesion of biomolecules on silicon based surfaces.

Biomolecules such as proteins, on silicon based surfaces are of extreme importance in various applications including microfabricated silicon implants, in the fabrication of microdevices with protein compounds (e.g., biosensors), and therapeutics. Morphology of silicon based surfaces with and without biomolecules and their adhesion with the substrate govern performance and reliability of the biological application. In this research, step by step morphological changes of silicon as well as adhesion during its surface modification have been studied using atomic force microscopy. To improve adhesion between biomolecules and the silicon based surfaces, chemical conjugation as well as surface patterning have been used. Changes in adhesion as a result of surface modification have been analyzed with the help of contact angle measurements. Phase imaging technique was used to confirm the presence of biomolecules on the surface. To understand the relationship between morphology and local values of adhesion, adhesion mapping and local stiffness mapping were carried out.

Object-oriented design tools for supramolecular devices and biomedical nanotechnology.

Nanotechnology provides multifunctional agents for in vivo use that increasingly blur the distinction between pharmaceuticals and medical devices. Realization of such therapeutic nanodevices requires multidisciplinary effort that is difficult for individual device developers to sustain, and identification of appropriate collaborations outside ones own field can itself be challenging. Further, as in vivo nanodevices become increasingly complex, their design will increasingly demand systems level thinking. System engineering tools such as object-oriented analysis, object-oriented design (OOA/D) and unified modeling language (UML) are applicable to nanodevices built from biological components, help logically manage the knowledge needed to design them, and help identify useful collaborative relationships for device designers. We demonstrate the utility of these systems engineering tools by reverse engineering an existing molecular device (the bacmid molecular cloning system) using them, and illustrate how object-oriented approaches identify fungible components (objects) in nanodevices in a way that facilitates design of families of related devices, rather than single inventions. We also explore the utility of object-oriented approaches for design of another class of therapeutic nanodevices, vaccines. While they are useful for design of current nanodevices, the power of systems design tools for biomedical nanotechnology will become increasingly apparent as the complexity and sophistication of in vivo nanosystems increases. The nested, hierarchical nature of object-oriented approaches allows treatment of devices as objects in higher-order structures, and so will facilitate concatenation of multiple devices into higher-order, higher-function nanosystems.

Anti-fouling properties of microstructured surfaces bio-inspired by rice leaves and butterfly wings.

Material scientists often look to biology for new engineering solutions to materials science problems. For example, unique surface characteristics of rice leaves and butterfly wings combine the shark skin (antifouling) and lotus leaf (self-cleaning) effects, producing the so-called rice and butterfly wing effect. In this paper, we study antifouling properties of four microstructured surfaces inspired by rice leaves and fabricated with photolithography and hot embossing techniques. Anti-biofouling effectiveness is determined with bioassays using Escherichia coli whilst inorganic fouling with simulated dirt particles. Antifouling data are presented to understand the role of surface geometrical features resistance to fouling. Conceptual modeling provides design guidance when developing novel antifouling surfaces for applications in the medical, marine, and industrial fields.

ImmunoFET feasibility in physiological salt environments.

Field-effect transistors (FETs) are solid-state electrical devices featuring current sources, current drains and semiconductor channels through which charge carriers migrate. FETs can be inexpensive, detect analyte without label, exhibit exponential responses to surface potential changes mediated by analyte binding, require limited sample preparation and operate in real time. ImmunoFETs for protein sensing deploy bioaffinity elements on their channels (antibodies), analyte binding to which modulates immunoFET electrical properties. Historically, immunoFETs were assessed infeasible owing to ion shielding in physiological environments. We demonstrate reliable immunoFET sensing of chemokines by relatively ion-impermeable III-nitride immunoHFETs (heterojunction FETs) in physiological buffers. Data show that the specificity of detection follows the specificity of the antibodies used as receptors, allowing us to discriminate between individual highly related protein species (human and murine CXCL9) as well as mixed samples of analytes (native and biotinylated CXCL9). These capabilities demonstrate that immunoHFETs can be feasible, contrary to classical FET-sensing assessment. FET protein sensors may lead to point-of-care diagnostics that are faster and cheaper than immunoassay in clinical, biotechnological and environmental applications.

A paramagnetic implant containing lithium naphthalocyanine microcrystals for high-resolution biological oximetry.

Lithium naphthalocyanine (LiNc) is a microcrystalline EPR oximetry probe with high sensitivity to oxygen [R.P. Pandian, M. Dolgos, C. Marginean, P.M. Woodward, P.C. Hammel, P.T. Manoharan, P. Kuppusamy, Molecular packing and magnetic properties of lithium naphthalocyanine crystal: hollow channels enabling permeability and paramagnetic sensitivity to molecular oxygen J. Mater. Chem. 19 (2009) 4138-4147]. However, direct implantation of the crystals in the tissue for in vivo oxygen measurements may be hindered by concerns associated with their direct contact with the tissue/cells and loss of EPR signal due to particle migration in the tissue. In order to address these concerns, we have developed encapsulations (chips) of LiNc microcrystals in polydimethyl siloxane (PDMS), an oxygen-permeable, bioinert polymer. Oximetry evaluation of the fabricated chips revealed that the oxygen sensitivity of the crystals was unaffected by encapsulation in PDMS. Chips were stable against sterilization procedures or treatment with common biological oxidoreductants. In vivo oxygen measurements established the ability of the chips to provide reliable and repeated measurements of tissue oxygenation. This study establishes PDMS-encapsulated LiNc as a potential probe for long-term and repeated measurements of tissue oxygenation.

A molecular paramagnetic spin-doped biopolymeric oxygen sensor.

Electron paramagnetic resonance (EPR) oximetry is a powerful technique capable of providing accurate, reliable, and repeated measurements of tissue oxygenation, which is crucial to the diagnosis and treatment of several pathophysiological conditions. Measurement of tissue pO(2) by EPR involves the use of paramagnetic, oxygen-sensitive probes, which can be either soluble (molecular) in nature or insoluble paramagnetic materials. Development of innovative strategies to enhance the biocompatibility and in vivo application of these oxygen-sensing probes is crucial to the growth and clinical applicability of EPR oximetry. Recent research efforts have aimed at encapsulating particulate probes in bioinert polymers for the development of biocompatible EPR probes. In this study, we have developed novel EPR oximetry probes, called perchlorotriphenylmethyl triester (PTM-TE):polydimethyl siloxane (PDMS) chips, by dissolving and incorporating the soluble (molecular) EPR probe, PTM-TE, in an oxygen-permeable polymer matrix, PDMS. We demonstrate that such incorporation (doping) of PTM-TE in PDMS enhanced its oxygen sensitivity several fold. The cast-molding method of fabricating chips enabled them to be made with increasing amounts of PTM-TE (spin density). Characterization of the spin distribution within the PDMS matrix, using EPR micro-imaging, revealed potential inhomogeneties, albeit with no adverse effect on the oxygen-sensing characteristics of PTM-TE:PDMS. The chips were resistant to autoclaving or in vitro oxidoreductant treatment, thus exhibiting excellent in vitro biostability. Our results establish PTM-TE:PDMS as a viable probe for biological oxygen-sensing, and also validate the incorporation of soluble probes in polymer matrices as an innovative approach to the development of novel probes for EPR oximetry.

Nanoscale adhesion, friction and wear studies of biomolecules on silane polymer-coated silica and alumina-based surfaces.

Proteins on biomicroelectromechanical systems (BioMEMS) confer specific molecular functionalities. In planar FET sensors (field-effect transistors, a class of devices whose protein-sensing capabilities we demonstrated in physiological buffers), interfacial proteins are analyte receptors, determining sensor molecular recognition specificity. Receptors are bound to the FET through a polymeric interface, and gross disruption of interfaces that removes a large percentage of receptors or inactivates large fractions of them diminishes sensor sensitivity. Sensitivity is also determined by the distance between the bound analyte and the semiconductor. Consequently, differential properties of surface polymers are design parameters for FET sensors. We compare thickness, surface roughness, adhesion, friction and wear properties of silane polymer layers bound to oxides (SiO(2) and Al(2)O(3), as on AlGaN HFETs). We compare those properties of the film-substrate pairs after an additional deposition of biotin and streptavidin. Adhesion between protein and device and interfacial friction properties affect FET reliability because these parameters affect wear resistance of interfaces to abrasive insult in vivo. Adhesion/friction determines the extent of stickage between the interface and tissue and interfacial resistance to mechanical damage. We document systematic, consistent differences in thickness and wear resistance of silane films that can be correlated with film chemistry and deposition procedures, providing guidance for rational interfacial design for planar AlGaN HFET sensors.

A determinative and confirmatory method for residues of the metabolites of carbadox and olaquindox in porcine tissues.

Carbadox (CBX) and olaquindox (OLQ) are used in swine feed for growth promotion, to improve feed efficiency, increase the rate of weight gain, control swine dysentery and bacterial enteritis in young swine. In 1991, the Joint FAO/WHO Expert Committee on Food Additives (JECFA) recommended maximum residue limits (MRLs) of 30 and 5mugkg(-1) in liver and muscle tissues of pigs, respectively, based on the concentration of, and expressed as, quinoxaline-2-carboxylic acid (QCA) as marker residue. In 1998, the European Commission (EC) banned the use of CBX and OLQ in food animal production together with four other feed additives, following reports that CBX and desoxycarbadox (DCBX) are suspect carcinogens and mutagens. In 2001, the sale of CBX was halted in Canada. In 2003, JECFA recommended the withdrawal of the previously recommended acceptable daily intake (ADI) and MRLs and concluded that QCA was not a suitable marker residue for CBX, based on new sponsor studies reporting that DCBX, the suspect carcinogen, persisted in animal tissues much longer than had previously been thought. This paper presents a very sensitive LC-MS/MS method that was developed by CFIA scientists for the simultaneous determination and confirmation of DCBX residues at concentrations >/=0.050 ngkg(-1) and QCA and mQCA residues at concentrations >/=0.50 ngkg(-1)in bovine muscle, pork liver and muscle tissues.

A folic acid-based functionalized surface for biosensor systems.

The performance of a biosensor depends largely on its interface with the biological system. This interface imparts a biologically relevant function to the device and provides a measure of specificity towards the biological analyte of interest. This paper documents the choice of folic acid as the functional component of a cantilever sensor to recognize nasopharyngeal (KB) cancer cells. A conjugation chemistry protocol has been outlined to deploy folic acid onto a titanium-coated sensor surface using a silane linker. The presence and biological activity of the sensor was verified by means of an immunospecific (ELISA) procedure. The overall performance of the folic acid-based cantilever sensor was measured using cancerous KB cell-binding experiments.

Localization to atherosclerotic plaque and biodistribution of biochemically derivatized superparamagnetic iron oxide nanoparticles (SPIONs) contrast particles for magnetic resonance imaging (MRI).

Annexin V recognizes apoptotic cells by specific molecular interaction with phosphatidyl serine, a lipid that is normally sequestered in the inner leaflet of the cell membrane, but is translocated to the outer leaflet in apoptotic cells, such as foam cells of atherosclerotic plaque. Annexin V could potentially deliver carried materials (such as superparamagnetic contrast agents for magnetic resonance imaging) to sites containing apoptotic cells, such as high grade atherosclerotic lesions, so we administered biochemically-derivatized (annexin V) superparmagnetic iron oxide particles (SPIONs) parenterally to two related rabbit models of human atherosclerosis. We observe development of negative magnetic resonance imaging (MRI) contrast in atheromatous lesions and but not in healthy artery. Vascular targeting by annexin V SPIONs is atheroma-specific (i.e., does not occur in healthy control rabbits) and requires active annexin V decorating the SPION surface. Targeted SPIONs produce negative contrast at doses that are 2,000-fold lower than reported for non-specific atheroma uptake of untargeted superparamagnetic nanoparticles in plaque in the same animal model. Occlusive and mural plaques are differentiable. While most of the dose accumulates in liver, spleen, kidneys and bladder, annexin V SPIONs also partition rapidly and deeply into early apoptotic foamy macrophages in plaque. Contrast in plaque decays within 2 months, allowing MRI images to be replicated with a subsequent, identical dose of annexin V SPIONs. Thus, biologically targeted superparamagnetic contrast agents can contribute to non-invasive evaluation of cardiovascular lesions by simultaneously extracting morphological and biochemical data from them.

New technologies for nutrition research.

The Experimental Biology 2003 symposium entitled "New Technologies for Nutrition Research" was organized to highlight new and emerging technologies, including nanotechnology and proteomics, and to suggest ways for their integration into nutrition research. Speakers focused on topics that included accelerator mass spectrometry for ultra-low level radiolabel tracing, nanodevices for real-time optical intracellular sensing, mass spectrometric techniques for examining protein expression, as well as potential applications for nanotechnology in the food sciences. These technologies may be particularly useful in obtaining accurate spatial information and low-level detection of essential and nonessential bioactive food components (nutrients) and their metabolites, and in enhancing the understanding of the impact of nutrient/metabolite and biomolecular interactions. Highlights from this symposium are presented briefly herein.