Engineering Papers⌕ Search

SEARCH · Engineering Papers

Results for “therapeutic design”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 235 records · Page 13

Covalent Drug Binding in Live Cells Monitored by Mid-Infrared Quantum Cascade Laser Spectroscopy: Photoactive Yellow Protein as a Model System

The detection of drug-target interactions in live cells enables analysis of therapeutic compounds in a native cellular environment. Recent advances in spectroscopy and molecular biology have facilitated the development of genetically encoded vibrational probes like nitriles that can sensitively report on molecular interactions. Nitriles are powerful tools for measuring electrostatic environments within condensed media like proteins, but such measurements in live cells have been hindered by low signal-to-noise ratios. In this study, we design a spectrometer based on a double-beam quantum cascade laser (QCL)-based transmission infrared (IR) source with balanced detection that can significantly enhance sensitivity to nitrile vibrational probes embedded in proteins within cells compared to a conventional FTIR spectrometer. Here, using this approach, we detect small-molecule binding in Escherichia coli, with particular focus on the interaction between para-Coumaric acid (pCA) and nitrile-incorporated photoactive yellow protein (PYP). This system effectively serves as a model for investigating covalent drug binding in a cellular environment. Notably, we observe large spectral shifts of up to 15 cm –1 for nitriles embedded in PYP between the unbound and drug-bound states directly within bacteria, in agreement with observations for purified proteins. Such large spectral shifts are ascribed to the changes in the hydrogen-bonding environment around the local environment of nitriles, accurately modeled through high-level molecular dynamics simulations using the AMOEBA force field. Our findings underscore the QCL spectrometer’s ability to enhance sensitivity for monitoring drug–protein interactions, offering new opportunities for advanced methodologies in drug development and biochemical research.

chromophores↗

Selective inhibition of cullin 3 neddylation through covalent targeting DCN1 protects mice from acetaminophen-induced liver toxicity

Cullin-RING E3 ligases (CRLs) regulate the turnover of approximately 20% of mammalian cellular proteins. Neddylation of individual cullin proteins is essential for the activation of each CRL. We report herein the discovery of DI-1548 and DI-1859 as two potent, selective and covalent DCN1 inhibitors. These inhibitors selectively inhibit neddylation of cullin 3 in cells at low nanomolar concentrations and are 2–3 orders of magnitude more potent than our previously reported reversible DCN1 inhibitor. Mass spectrometric analysis and co-crystal structures reveal that these compounds employ a unique mechanism of covalent bond formation with DCN1. DI-1859 induces a robust increase of NRF2 protein, a CRL3 substrate, in mouse liver and effectively protects mice from acetaminophen-induced liver damage. Taken together, this study demonstrates the therapeutic potential of selective inhibition of cullin neddylation.

59 BASIC BIOLOGICAL SCIENCES↗

An activatable NIR fluorescent rosol for selectively imaging nitroreductase activity

Hypoxia (i.e., pO 2 ≤ ~1.5 %) is an important characteristic of tumor microenvironments that directly correlates with resistance against first-line therapies and tumor proliferation/infiltration. The ability to accurately identify hypoxic tumor cells/tissue could afford tailored therapeutic regimens for personalized treatment, the development of more-effective therapies, and discerning the mechanisms underlying disease progression. Fluorogenic constructs currently developed for identifying such tumor cells/tissue operate by targeting the bioreductive activity of primarily the nitroreductase (NTR) class of enzymes, but collectively such constructs unfortunately present photophysical and/or physicochemical shortcomings that could limit their effectiveness upon implementation. To overcome these limitations, we present the rational design, development, and evaluation of the first activatable ultracompact xanthene core-based molecular probe (NO 2 -Rosol) for selectively imaging NTR activity that affords an “OFF-ON” near-infrared (NIR) fluorescence response (ca. > 700 nm) alongside a remarkable Stokes shift (ca. > 150 nm) via NTR activity-facilitated modulation to its energetics whereby the resultant interplay discontinues an intramolecular d-PET fluorescence-quenching mechanism transpiring between directly-linked electronically-uncoupled π-systems comprising its components. DFT calculations guided selection of a suitable fluorogenic scaffold and nitroaromatic moiety candidate that when adjoined could (i) afford such photophysical response upon bioreduction by upregulated NTR activity in hypoxic tumor cells/tissue and (ii) employ a retention mechanism strategy that capitalizes on an inherent physical property of the NIR fluorogenic scaffold for achieving signal amplification. NO 2 -Rosol demonstrated 705 nm NIR fluorescence emission and a 157 nm Stokes shift, selectivity for NTR over relevant bioanalytes, and a 28- and 12-fold fluorescence enhancement in solution and between cells cultured under different oxic conditions, respectively. Finally, in establishing feasibility for NO 2 -Rosol to provide favorable contrast levels in in solutioand in vitrostudies, we anticipate NO 2 -Rosol similarly doing so in future studies towards its translation.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗

The Promise of Mutation Resistant Drugs for SARS-CoV-2 That Interdict in the Folding of the Spike Protein Receptor Binding Domain

In recent work, we proposed that effective therapeutic drugs aimed at treating the SARS-CoV-2 infection could be developed based on interdicting in the early steps of the folding pathway of key viral proteins, including the receptor binding domain (RBD) of the spike protein. In order to provide for a drug target on the protein, the earliest contact-formation event along the dominant folding pathway of the RBD spike protein was predicted employing the Sequential Collapse Model (SCM). The segments involved in the predicted earliest contact were suggested to provide optimal folding interdiction target regions (FITRs) for potential therapeutic drugs, with a focus on folding interdicting peptides (FIPs). In this paper, we extend our analysis to include 13 known single mutations of the RBD spike protein as well as the triple mutation B1.351 and the recent double mutation B1.617.2. The results show that the location of the FITR does not change in any of the 15 studied mutations, providing for a mutation-resistant drug design strategy for the RBD-spike protein.

Bergasa-Caceres, Fernando↗

Comprehensive deletion landscape of CRISPR-Cas9 identifies minimal RNA-guided DNA-binding modules

Proteins evolve through the modular rearrangement of elements known as domains. Extant, multidomain proteins are hypothesized to be the result of domain accretion, but there has been limited experimental validation of this idea. Here, we introduce a technique for genetic minimization by iterative size-exclusion and recombination (MISER) for comprehensively making all possible deletions of a protein. Using MISER, we generate a deletion landscape for the CRISPR protein Cas9. We find that the catalytically-dead Streptococcus pyogenes Cas9 can tolerate large single deletions in the REC2, REC3, HNH, and RuvC domains, while still functioning in vitro and in vivo, and that these deletions can be stacked together to engineer minimal, DNA-binding effector proteins. In total, our results demonstrate that extant proteins retain significant modularity from the accretion process and, as genetic size is a major limitation for viral delivery systems, establish a general technique to improve genome editing and gene therapy-based therapeutics.

59 BASIC BIOLOGICAL SCIENCES↗

Autonomous Medical Care for Exploration Class Space Missions

The US-based health care system of the International Space Station (ISS) contains several subsystems, the Health Maintenance System, Environmental Health System and the Countermeasure System. These systems are designed to provide primary, secondary and tertiary medical prevention strategies. The medical system deployed in Low Earth Orbit (LEO) for the ISS is designed to enable a "stabilize and transport" concept of operations. In this paradigm, an ill or injured crewmember would be rapidly evacuated to a definitive medical care facility (DMCF) on Earth, rather than being treated for a protracted period on orbit. The medical requirements of the short (7 day) and long duration (up to 6 months) exploration class missions to the Moon are similar to LEO class missions with the additional 4 to 5 days needed to transport an ill or injured crewmember to a DCMF on Earth. Mars exploration class missions are quite different in that they will significantly delay or prevent the return of an ill or injured crewmember to a DMCF. In addition the limited mass, power and volume afforded to medical care will prevent the mission designers from manifesting the entire capability of terrestrial care. NASA has identified five Levels of Care as part of its approach to medical support of future missions including the Constellation program. In order to implement an effective medical risk mitigation strategy for exploration class missions, modifications to the current suite of space medical systems may be needed, including new Crew Medical Officer training methods, treatment guidelines, diagnostic and therapeutic resources, and improved medical informatics.

Hamilton, Douglas↗

Design and structural basis of selective 1,4-dihydropyridine inhibitors of the calcium-activated potassium channel K Ca 3.1

The 1,4-dihydropyridines, drugs with well-established bioavailability and toxicity profiles, have proven efficacy in treating human hypertension, peripheral vascular disorders, and coronary artery disease. Every 1,4-dihydropyridine in clinical use blocks L-type voltage-gated calcium channels. We now report our development, using selective optimization of a side activity (SOSA), of a class of 1,4-dihydropyridines that selectively and potently inhibit the intermediate-conductance calcium-activated K + channel K Ca 3.1, a validated therapeutic target for diseases affecting many organ systems. One of these 1,4-dihydropyridines, DHP-103, blocked K Ca 3.1 with an IC 50 of 6 nM and exhibited exquisite selectivity over calcium channels and a panel of >100 additional molecular targets. Using high-resolution structure determination by cryogenic electron microscopy together with mutagenesis and electrophysiology, we delineated the drug binding pocket for DHP-103 within the water-filled central cavity of the K Ca 3.1 channel pore, where bound drug directly impedes ion permeation. DHP-103 inhibited gain-of-function mutant K Ca 3.1 channels that cause hereditary xerocytosis, suggesting its potential use as a therapeutic for this hemolytic anemia. In a rat model of acute ischemic stroke, the second leading cause of death worldwide, DHP-103 administered 12 h postischemic insult in proof-of-concept studies reduced infarct volume, improved balance beam performance (measure of proprioception) and decreased numbers of activated microglia in infarcted areas. K Ca 3.1-selective 1,4-dihydropyridines hold promise for the many diseases for which K Ca 3.1 has been experimentally confirmed as a therapeutic target.

Ong, Seow Theng [Lee Kong Chian School of Medicine↗

MicroRNA expression in animal models of amyotrophic lateral sclerosis and potential therapeutic approaches

A review of recent animal models of amyotrophic lateral sclerosis showed a large number of miRNAs had altered levels of expression in the brain and spinal cord, motor neurons of spinal cord and brainstem, and hypoglossal, facial, and red motor nuclei and were mostly upregulated. Among the miRNAs found to be upregulated in two of the studies were miR-21, miR-155, miR-125b, miR-146a, miR-124, miR-9, and miR-19b, while those downregulated in two of the studies included miR-146a, miR-29, miR-9, and miR-125b. A change of direction in miRNA expression occurred in some tissues when compared (e.g., miR-29b-3p in cerebellum and spinal cord of wobbler mice at 40 days), or at different disease stages (e.g., miR-200a in spinal cord of SOD1(G93A) mice at 95 days vs. 108 and 112 days). In the animal models, suppression of miR-129-5p resulted in increased lifespan, improved muscle strength, reduced neuromuscular junction degeneration, and tended to improve motor neuron survival in the SOD1(G93A) mouse model. Suppression of miR-155 was also associated with increased lifespan, while lowering of miR-29a tended to improve lifespan in males and increase muscle strength in SOD1(G93A) mice. Overexpression of members of miR-17~92 cluster improved motor neuron survival in SOD1(G93A) mice. Treatment with an artificial miRNA designed to target hSOD1 increased lifespan and improved muscle strength in SOD1(G93A) animals. Further studies with animal models of amyotrophic lateral sclerosis are warranted to validate these findings and identify specific miRNAs whose suppression or directed against hSOD1 results in increased lifespan, improved muscle strength, reduced neuromuscular junction degeneration, and improved motor neuron survival in SOD1(G93A) animals.

59 BASIC BIOLOGICAL SCIENCES↗

Designing Cyclic Nitrogen‐Bridged Sulfonamides with Anti‐Cancer Activity

The N-bridgehead heterocyclic structure is an abundant motif in a multitude of natural products. This structural feature is of high interest because it is present in many different bioactive molecules, many of which are well-established pharmaceuticals. The introduction of a sulfone group into the N-bridgehead system yields a new core structure containing a N-bridgehead sulfonamide. While linear sulfonamides can be found in natural products, only artificial cyclic sulfonamides are known to date. Applications of related cyclic sulfonamide compounds include matrix metalloproteinase inhibitors, potential HIV and cancer therapeutics, and anti-inflammatory compounds. To explore the potential bioactivity of the N-bridgehead sulfonamide scaffold, a synthetic route toward these scaffolds is developed and their bioactivity is explored against different cancer cell lines.

60 APPLIED LIFE SCIENCES↗

The Impact of Variability in Patient Exposure During Premarket Clinical Development on Postmarket Safety Outcomes

We characterized the size of the premarket safety population for 278 small-molecule new molecular entities (NMEs) and 61 new therapeutic biologics (NTBs) approved by the US Food and Drug Administration (FDA) between October 1, 2002, and December 31, 2014, evaluating the relationship of premarket safety population size to regulatory characteristics and postmarket safety outcomes. The median size of the safety population was 1,044, and was lower for NTBs than NMEs (median: 920 vs. 1,138, P = 0.04), orphan products than nonorphan products (393 vs. 1,606, P < 0.001), and for products with fast-track designation (617 vs. 1,455, P < 0.001), priority review (630 vs. 1,735, P < 0.001), and accelerated approval (475 vs. 1,164, P < 0.001), than products without that designation. The median number of postmarket safety label updates and issues added to the label were higher with larger premarket exposure among nonorphan products, but not among orphan products. Products with accelerated approval using a surrogate end point had a higher median number of safety issues added to the label than those with full approval, but this did not vary with the size of the safety population; fast-track and priority review were not associated with the number of safety issues added to the label. Here, a smaller safety population size was associated with a longer time to first safety outcome for nonorphan products but not orphan products. For orphan and nonorphan products combined, smaller premarket safety population size is not associated with the number or timing of postmarket safety outcomes, regardless of expedited program participation.

60 APPLIED LIFE SCIENCES↗

A Survey of Preclinical Studies Evaluating Nanoparticle-Based Vaccines Against Non-Viral Sexually Transmitted Infections

A worldwide estimate of over one million STIs are acquired daily and there is a desperate need for effective preventive as well as therapeutic measures to curtail this global health burden. Vaccines have been the most effective means for the control and potential eradication of infectious diseases; however, the development of vaccines against STIs has been a daunting task requiring extensive research for the development of safe and efficacious formulations. Nanoparticle-based vaccines represent a promising platform as they offer benefits such as targeted antigen presentation and delivery, co-localized antigen-adjuvant combinations for enhanced immunogenicity, and can be designed to be biologically inert. Here we discuss promising types of nanoparticles along with outcomes from nanoparticle-based vaccine preclinical studies against non-viral STIs including chlamydia, syphilis, gonorrhea, and recommendations for future nanoparticle-based vaccines against STIs.

59 BASIC BIOLOGICAL SCIENCES↗

AbBERT: Learning Antibody Humanness via Masked Language Modeling

Understanding the degree of humanness of antibody sequences is critical to the therapeutic antibody development process to reduce the risk of failure modes like immunogenicity or poor manufacturability. We introduce AbBERT, a transformer-based language model trained on up to 20 million unpaired heavy/light chain sequences from the Observed Antibody Space database. We first validate AbBERT using a novel “multi-mask” scoring procedure to demonstrate high accuracy in predicting complementary determining regions—including the challenging hypervariable H3 region. We then demonstrate several uses of AbBERT at various points along the antibody design process. AbBERT enhances in silico antibody optimization via deep reinforcement learning by utilizing its learned embeddings as additional observations during optimization. Within a larger computational antibody design platform, AbBERT has been successfully applied as an additional design objective, where it displays strong correlations with computational tools predicting antibody structural stability. Finally, mutant antibody sequences that have been scored as unfavorable by AbBERT have shown corresponding low yields when expressed in cells. These use cases demonstrate the power of language modeling within computational antibody design.

Bioinformatics↗

Let Dependent Low Dose and Synergistic Inhibition of Human Angiogenesis by Charged Particles: Validation of Micrornas That Drive Inhibition

The microvasculature permeates all tissues at the microscopic level making the whole body a target for Space Radiation. Depending on the trajectory a single heavy ion particle would traverse many micro-vessels as it passes through the body causing a widespread response. Studies on the effects of charged particles on the development of human 3D micro-vessel models show that angiogenesis is inhibited by all ions detectible at a dose of 1.25c Gy. However, there are two distinct mechanisms of inhibition depending on the linear energy transfer (LET). We show here that the inhibition of angiogenesis is demarcated into two groups. The blockage of the early motile stage of micro-vessel development occurs after exposure to light ions (LET 3 KeV/n or lower) whereas the prevention of the later stages of development when the microvessels widen into tubes occurs after exposure to heavy ions (LET 8 KeV/n or higher). Strikingly, the combined effect of each ion has a synergistic effect detectible as low as 0.6 cGy. The low fluence of these doses indicates a bystander effect where the response is transmitted to other cells by the secretion of molecules by targeted cells. Prime candidates are microRNAs (miRNAs) and we have previously identified three angiogenesis-associated miRNA regulators from serum, cardiac tissue, and micro-vessels exposed to a simplified Galactic Cosmic Radiation (GCR) simulation – a mixture of heavy and light ions found in Space. Synthetic molecules (Antagomirs) designed to inhibit the predicted miRNAs were successfully used to reverse the inhibition of angiogenesis by Space Radiation. With the simple application of the antagomirs as a countermeasure we have for the first time shown an amelioration of the complex response(s) of angiogenesis to Space Radiation. This opens a new avenue of possible mitigation strategies based on the regulation and understanding of master regulators. These results not only have impact with Space Radiation research, but also provide clues of possible therapeutics for terrestrial diseases in the clinical setting.

Yen-Ruh Wuu↗

In vivo stabilization of a less toxic asparaginase variant leads to a durable antitumor response in acute leukemia

Asparagine is a non-essential amino acid since it can either be taken up via the diet or synthesized by asparagine synthetase. Acute lymphoblastic leukemia (ALL) cells do not express asparagine synthetase or express it only minimally, which makes them completely dependent on extracellular asparagine for their growth and survival. This dependency makes ALL cells vulnerable to treatment with L-asparaginase, an enzyme that hydrolyzes asparagine. To date, all clinically approved L-asparaginases have significant L-glutaminase co-activity, associated with non-immune related toxic side effects observed during therapy. Therefore, reduction of L-glutaminase co-activity with concomitant maintenance of its anticancer L-asparaginase effect may effectively improve the tolerability of this unique drug. Previously, we designed a new alternative variant of Erwinia chrysanthemi (ErA; Erwinaze) with decreased L-glutaminase co-activity, while maintaining its L-asparaginase activity, by the introduction of three key mutations around the active site (ErA-TM). However, Erwinaze and our ErA-TM variant have very short half-lives in vivo. Here, we show that the fusion of ErA-TM with an albumin binding domain (ABD)-tag significantly increases its in vivo persistence. In addition, we evaluated the in vivo therapeutic efficacy of ABD-ErA-TM in a B-ALL xenograft model of SUP-B15. Our results show a comparable long-lasting durable antileukemic effect between the standard-of-care pegylated-asparaginase and ABD-ErA-TM L-asparaginase, but with fewer co-glutaminase-related acute side effects. Since the toxic side effects of current L-asparaginases often result in treatment discontinuation in ALL patients, this novel ErA-TM variant with ultra-low L-glutaminase co-activity and long in vivo persistence may have great clinical potential.

60 APPLIED LIFE SCIENCES↗

Efficacy and Delivery of Novel FAST Agents for Coronaviruses

We proposed to test and develop advanced delivery for novel agents from our collaborators Facile Accelerated Specific Therapeutics (FAST) platform to reduce coronavirus replication. Sachi Bioworks Inc., Prof. Anushree Chatterjee, and Prof. Prashant Nagpal at the University of Colorado Boulder have developed a bioinformatics and synthesis pipeline to produce sequence specific theranostic agents (agents that can be therapies and/or diagnostics) that are inherently transported into the cytoplasm of mammalian host cells and sequence-specifically interfere in nucleic acid replication. The agent comprises a small nanoparticle (2-5 nm) chosen for ideal cellular transport and/or imaging conjugated to a short, synthetic DNA analog oligomer designed for binding to one or more target viral sequences. The sequence specific binding of the FAST agent to its target prevents nucleic acid replication due to its high affinity binding. While the small nanoparticle facilitates delivery in vitro, we plan to package the FAST agents into a larger nanoparticle (80-300 nm) for future in vivo delivery applications. Our team at Sandia has expertise encapsulating biomolecules including protein, DNA, and RNA into solid lipid nanoparticles (LNP) and lipid coated mesoporous silica nanoparticles (LC-MSN) and shown successful delivery in mouse models to multiple tissues. Our team focused on formulation parameters for FAST agents into lipid nanoparticles (LNP) and lipid coated mesoporous silica nanoparticles (LC-MSN) for enhanced delivery and/or efficacy and in vivo translation. We used lipid formulas that have been shown in literature to facility in vitro and more importantly, in vivo delivery. In our work discussed below, we successfully demonstrate loading and release of FAST agents on silica core and stable LC-MSN in a reasonable size range for in vivo testing.

59 BASIC BIOLOGICAL SCIENCES↗

National Virtual Biotechnology Laboratory: Report on Rapid R&D Solutions to the COVID-19 Crisis

With funding from the CARES Act, the U.S Department of Energy (DOE) established the National Virtual Biotechnology Laboratory (NVBL) in March 2020 to address key challenges associated with the COVID-19 crisis. NVBL brought together the broad scientific and technical expertise and resources of DOE’s 17 national laboratories to help tackle medical supply short ages, discover potential drugs to fight the virus, develop and validate COVID-19 testing methods, model disease spread and impact across the nation, and understand virus transport in buildings and the environment. National laboratory resources leveraged for this effort include a suite of world-leading user facilities broadly available to the research community, such as light and neutron sources, nanoscale science research centers, sequencing and biocharacterization facilities, and high-performance computing facilities. Within months, NVBL teams produced innovations in materials and advanced manufacturing that mitigated shortages in test kits and personal protective equipment (PPE), creating nearly 1,000 new jobs. They used DOE’s high-performance computers and light and neutron sources to identify promising candidates for antibodies and antivirals that universities and drug companies are now evaluating. NVBL researchers also developed new diagnostic targets and sample collection approaches, and supported U.S. Food and Drug Administration (FDA), Centers for Disease Control and Prevention (CDC), and U.S. Department of Defense (DoD) efforts to establish national guidelines used in administering millions of tests. Researchers used artificial intelligence and high-performance computing to produce near-real-time data analysis to forecast disease transmission, stress on public health infrastructure, and economic impact, which supported decision-makers at the local, state, and national levels. NVBL teams also studied how to control indoor virus movement to minimize uptake and protect human health. NVBL’s accomplishments demonstrate not only the powerful resource represented by DOE’s national laboratories working together to meet national needs, but also the effectiveness of the integrated NVBL framework for rapidly responding to emergencies with research and development (R&D) solutions. As the fight against COVID continues, sustained efforts are needed to confront this pandemic as well as future threats. Examples include: 1) Establishing “supply chains on demand” to meet emergency production needs by leveraging the materials and manufacturing expertise of DOE national laboratories and developing advances in electronics, sensing, robotics, and automation capabilities; 2) Improving the speed and robustness of drug discovery by integrating experimental platforms with DOE’s computational and experimental user facilities, which provide unique resources to support the discovery of high-potential therapeutic agents; 3) Protecting public, environmental, and animal health by developing new testing protocols and instrumentation adaptable to diverse sample types (both physiological and environmental) to quickly detect a wide range of pathogens and monitor other biorisks; 4) Supporting near-real-time data needs of decision-makers at the local, regional, state, and national levels by advancing data curation, analysis, and modeling using artificial intelligence and new data science tools for managing and evaluating large diverse datasets; 5) Harnessing DOE’s expertise in environmental modeling to design rooms and air handling for offices, classrooms, restaurants, and other structures to minimize biorisk transmissions. Going forward, NVBL is poised to apply the unique capabilities and expertise of the national laboratory complex to future national and international emergencies, both natural and engineered. Through this framework, the Office of Science will continue to be an integral component of agency wide efforts to prepare for and respond to biorisks and other crises.

42 ENGINEERING↗

Stability of Formulations Contained in the Pharmaceutical Payload Aboard Space Missions

Efficacious pharmaceuticals with adequate shelf life are essential for successful space medical operations in support of space exploration missions. Physical and environmental factors unique to space missions such as vibration, G forces and ionizing radiation may adversely affect stability of pharmaceuticals intended for standard care of astronauts aboard space missions. Stable pharmaceuticals, therefore, are of paramount importance for assuring health and wellness of astronauts in space. Preliminary examination of stability of formulations from Shuttle and International Space Station (ISS) medical kits revealed that some of these medications showed physical and chemical degradation after flight raising concern of reduced therapeutic effectiveness with these medications in space. A research payload experiment was conducted with a select set of formulations stowed aboard a shuttle flight and on ISS. The payload consisted of four identical pharmaceutical kits containing 31 medications in different dosage forms that were transported to the International Space Station (ISS) aboard the Space Shuttle, STS 121. One of the four kits was stored on the shuttle and the other three were stored on the ISS for return to Earth at six months intervals on a pre-designated Shuttle flight for each kit; the shuttle kit was returned to Earth on the same flight. Standard stability indicating physical and chemical parameters were measured for all pharmaceuticals returned from the shuttle and from the first ISS increment payload along with ground-based matching controls. Results were compared between shuttle, ISS and ground controls. Evaluation of data from the three paradigms indicates that some of the formulations exhibited significant degradation in space compared to respective ground controls; a few formulations were unstable both on the ground and in space. An increase in the number of pharmaceuticals from ISS failing USP standards was noticed compared to those from the shuttle flight. A comprehensive evaluation of results is in progress.

Putcha, Lakshmi↗

Drugsniffer: An Open Source Workflow for Virtually Screening Billions of Molecules for Binding Affinity to Protein Targets

The SARS-CoV2 pandemic has highlighted the importance of efficient and effective methods for identification of therapeutic drugs, and in particular has laid bare the need for methods that allow exploration of the full diversity of synthesizable small molecules. While classical high-throughput screening methods may consider up to millions of molecules, virtual screening methods hold the promise of enabling appraisal of billions of candidate molecules, thus expanding the search space while concurrently reducing costs and speeding discovery. Here, we describe a new screening pipeline, called drugsniffer, that is capable of rapidly exploring drug candidates from a library of billions of molecules, and is designed to support distributed computation on cluster and cloud resources. As an example of performance, our pipeline required ~40,000 total compute hours to screen for potential drugs targeting three SARS-CoV2 proteins among a library of ~3.7 billion candidate molecules.

59 BASIC BIOLOGICAL SCIENCES↗