A randomized, double-blind, comparative study of the pharmacodynamics and pharmacokinetics of GP40141 (romiplostim biosimilar) and reference romiplostim in healthy male volunteers.

AIMS: The pharmacodynamic (PD) similarity between GP40141, a proposed romiplostim biosimilar, and reference romiplostim was evaluated. Pharmacokinetics and safety were also assessed. METHODS: In this phase 1, randomized, double-blind, single-dose, crossover comparative study with an adaptive design, 56 healthy male volunteers were randomized 1:1 to receive a 3 ug × kg-1 subcutaneous dose of GP40141 and reference romiplostim. The PD similarity between GP40141 and the reference romiplostim was determined using the standard equivalence criteria (80%-125%) for the area under the platelet count-time curve from time 0 to the time of the last sampling for PD (AUCplt ) and the maximum observed platelet count (Pmax ). RESULTS: GP40141 and the reference romiplostim exhibited similar PD profiles. 90% CI for the geometric mean ratios for the primary PD parameters (AUCplt, Pmax ) for GP40141 (T) and the reference romiplostim (R) were fully contained within the predefined equivalence limits of 80%-125%: 98.13%-102.42% for AUCplt and 97.56%-105.80% for Pmax . The pharmacokinetic profiles of GP40141 and the reference romiplostim were well described. No adverse events were observed during the clinical trial after the administration of GP40141 and the reference romiplostim. CONCLUSION: This study demonstrates the PD similarity of GP40141 to the reference romiplostim. Both treatments had comparable safety profiles (NCT05652595).

Fecal Microbiota and Diet Composition of Buryatian Horses Grazing Warm- and Cold-Season Grass Pastures.

The Buryatian horse is an ancient breed and, as an indigenous breed, they have unique adaptive abilities to use scarce pastures, graze in winter, and survive in harsh conditions with minimal human care. In this study, fecal microbiota of Buryatian horses grazing in the warm and cold seasons were investigated using NGS technology on the Illumina MiSeq platform. We hypothesized that the composition of microbial communities in the feces of horses maintained on pasture would change in the different seasons, depending on the grass availability and different plant diets. We conducted microhistological fecal studies of horse diet composition on steppe pasture. The alpha diversity analysis showed horses had a more abundant and diverse gut microbiota in summer. There were significant effects on the beta diversity of microbial families, which were clustered by the warm and cold season in a principal coordinate analysis (PCoA), with 45% of the variation explained by two principal coordinates. This clustering by season was further confirmed by the significant differences observed in the relative abundances of microbial families and genera. The obtained results can serve as an experimental substantiation for further study of the impact of pasture grasses, which have a pharmacological effect, on the diversity of the gut microbiome and horse health.

Computational determination of toxicity risks associated with a selection of approved drugs having demonstrated activity against COVID-19.

BACKGROUND: The emergence and rapid spread of SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2) in thelate 2019 has caused a devastating global pandemic of the severe pneumonia-like disease coronavirus disease 2019 (COVID-19). Although vaccines have been and are being developed, they are not accessible to everyone and not everyone can receive these vaccines. Also, it typically takes more than 10 years until a new therapeutic agent is approved for usage. Therefore, repurposing of known drugs can lend itself well as a key approach for significantly expediting the development of new therapies for COVID-19. METHODS: We have incorporated machine learning-based computational tools and in silico models into the drug discovery process to predict Adsorption, Distribution, Metabolism, Excretion, and Toxicity (ADMET) profiles of 90 potential drugs for COVID-19 treatment identified from two independent studies mainly with the purpose of mitigating late-phase failures because of inferior pharmacokinetics and toxicity. RESULTS: Here, we summarize the cardiotoxicity and general toxicity profiles of 90 potential drugs for COVID-19 treatment and outline the risks of repurposing and propose a stratification of patients accordingly. We shortlist a total of five compounds based on their non-toxic properties. CONCLUSION: In summary, this manuscript aims to provide a potentially useful source of essential knowledge on toxicity assessment of 90 compounds for healthcare practitioners and researchers to find off-label alternatives for the treatment for COVID-19. The majority of the molecules discussed in this manuscript have already moved into clinical trials and thus their known pharmacological and human safety profiles are expected to facilitate a fast track preclinical and clinical assessment for treating COVID-19.

C subunit of the ATP synthase is an amyloidogenic calcium dependent channel-forming peptide with possible implications in mitochondrial permeability transition.

The c subunit is an inner mitochondrial membrane (IMM) protein encoded by three nuclear genes. Best known as an integral part of the F0 complex of the ATP synthase, the c subunit is also present in other cytoplasmic compartments in ceroid lipofuscinoses. Under physiological conditions, this 75 residue-long peptide folds into an α-helical hairpin and forms oligomers spanning the lipid bilayer. In addition to its physiological role, the c subunit has been proposed as a key participant in stress-induced IMM permeabilization by the mechanism of calcium-induced permeability transition. However, the molecular mechanism of the c subunit participation in IMM permeabilization is not completely understood. Here we used fluorescence spectroscopy, atomic force microscopy and black lipid membrane methods to gain insights into the structural and functional properties of unmodified c subunit protein that might make it relevant to mitochondrial toxicity. We discovered that c subunit is an amyloidogenic peptide that can spontaneously fold into ß-sheets and self-assemble into fibrils and oligomers in a Ca2+-dependent manner. C subunit oligomers exhibited ion channel activity in lipid membranes. We propose that the toxic effects of c subunit might be linked to its amyloidogenic properties and are driven by mechanisms similar to those of neurodegenerative polypeptides such as Aß and α-synuclein.

Influence of oscillating main flow on separation efficiency in asymmetrical flow field-flow fractionation.

The steadily rising interest in the investigation of interactions between nanomaterials and biological media has also led to an increasing interest in asymmetrical flow field-flow fractionation (AF-FFF). The biggest strength of AF-FFF is the possibility to alter the flow profiles to suit a specific separation problem. In this paper, the influence of an oscillating main flow on the separation efficiency of AF-FFF is investigated. Such oscillations can e.g. be caused by the main pump To investigate the influence of such flow conditions on the separation efficiency in AF-FFF systematically, different oscillation profiles were applied and their influence on the elution profile and the retention times was observed. It could be shown, that the separation mechanism is extremely robust and a fractionation is still possible even under unfavorable conditions.

Observation of interaction forces by investigation of the influence of eluent additives on the retention behavior of aqueous nanoparticle dispersions in asymmetrical flow field-flow fractionation.

The investigation and subsequent understanding of the interactions of nanomaterials with components of their surrounding media is important to be able to evaluate both potential use cases as well as potential risks for human health and for the environment. To investigate such interactions, asymmetrical flow field-flow fractionation (AF4) is an interesting analytical tool. This statement grounds on the fact that interactions of the analyte with the membrane and with components of the eluent are crucial for the retention behavior of the analyte within the field-flow fractionation (FFF) channel. Therefore, the investigation of the retention behavior provides an insight in the nature of the interactions between analyte, membrane and eluent. Within this publication, the influence of the composition of the eluent on the retention behavior of aqueous dispersions of two model analytes is investigated. Eluents with different types of salts and surfactants and eluents with different salt concentrations were prepared and the influence of the composition of these eluents on the retention behavior of polystyrene and polyorganosiloxane particles was compared. Three main trends were observed: Elution times increase with increasing electrolyte concentration; when comparing different electrolyte anions, the retention time increases the more kosmotropic the anion is; when comparing different electrolyte cations, the retention order depends on the surfactant. Additional dynamic light scattering (DLS) measurements were conducted to verify that the differences in retention times are not caused by actual differences in particle size. Instead, the differences in elution time can be correlated with the concentration and with the chao-/kosmotropicity of the added electrolyte ions. Therefore, AF4 proves to be sensitive to subtile changes of interaction forces on the level of Coulomb and van der Waals forces. The experimentally gathered elution times were used to develop a model describing the retention behavior, based on an enhanced version of the standard AF4 model: By introducing particle-medium-membrane interactions in the standard AF4 model via the respective Hamaker constants, the calculation of retention times was possible. The congruence of the calculated with the experimental retention times confirmed the validity of the simulation.

Intra-Articular Injections of a Whole Blood Clot Secretome, Autologous Conditioned Serum, Have Superior Clinical and Biochemical Efficacy Over Platelet-Rich Plasma and Induce Rejuvenation-Associated Changes of Joint Metabolism: A Prospective, Controlled Open-Label Clinical Study in Chronic Knee Osteoarthritis.

Osteoarthritis is a frequent, age-associated disease affecting >10% of world's population over 60 years of age. This study intended to compare intra-articular whole blood clot secretome (autologous conditioned serum [ACS], recently re-named blood clot secretome [BCS]) to platelet-rich plasma (PRP) in knee osteoarthritis (OA). A clinical, nonrandomized open-label comparison of ACS versus PRP in knee OA with subclinical or moderate synovitis symptomology was performed. One hundred and twenty-three patients with knee OA, Kellgren and Lawrence grade II-III, were each treated with six i.a. injections of ACS or PRP. The clinical efficacy was measured by visual analog scale and Western Ontario and McMaster Universities Arthritis Index (WOMAC) score. The biochemical effects measured include synovial fluid (SF) viscosity, cytokines interleukin (IL)-1Ra and IL-1b, radical footprint NO3, and conjugated dienes (CDs). At the 3-month follow-up, clinical efficacy of ACS was significant in all groups, versus PRP. PRP had significant versus baseline efficacy in subclinical, but not in moderate, synovitis cases. ACS was more effective than PRP regarding all analytical parameters. It induced endogenous IL-1Ra expression, downregulated IL-1b, and improved SF viscosity. ACS reduced-significantly stronger than PRP-the concentration of CDs-interpreted as reactive oxygen species footprints-and NO3-interpreted as nitric oxide footprint-in SF. ACS displayed significant efficacy in all groups, which was clinically and biochemically superior to PRP. ACS appears to improve i.a. homeostasis. Strength of this open clinical study is the combination of clinical and biochemical data.

Determination of Hamaker constants of polymeric nanoparticles in organic solvents by asymmetrical flow field-flow fractionation.

Interaction forces between all objects are either of repulsive or attractive nature. Concerning attractive interactions, the determination of dispersion forces are of special interest since they appear in all colloidal systems and have a crucial influence on the properties and processes in these systems. One possibility to link theory and experiment is the description of the London-Van der Waals forces in terms of the Hamaker constant, which leads to the challenging problem of calculating the van der Waals interaction energies between colloidal particles. Hence, the determination of a Hamaker constant for a given material is needed when interfacial phenomena such as adhesion are discussed in terms of the total potential energy between particles and substrates. In this work, the asymmetrical flow field-flow fractionation (AF-FFF) in combination with a Newton algorithm based iteration process was used for the determination of Hamaker constants of different nanoparticles in toluene.

Characterization of polymer nanoparticles by asymmetrical flow field flow fractionation (AF-FFF).

We present the characterization of different polymeric nanoparticles with asymmetrical flow field-flow fractionation (AF-FFF) in different solvents and additional, independent methods such as static and dynamic light scattering (SLS, DLS) in solution and transmission electron microscopy (TEM) and atomic force microscopy (AFM) for the visualization of the nanoparticles on solid substrates. AF-FFF proves to be a powerful technique to determine average sizes of nanoparticles such as multifunctional polyorganosiloxane nanospheres both, in aqueous dispersion and in organic solvents such as toluene. In addition, dye loaded block copolymer vesicles and cylindrical polyelectrolyte type polymacromonomers are successfully analyzed by AF-FFF and the obtained results are compared to the other techniques used.

Factors governing loss and rescue of DNA binding upon single and double mutations in the p53 core domain.

The mutation of R273-->H in the p53 core domain (p53-CD) is one of the most common mutations found in human cancers. Although the 273H p53-CD retains the wild-type conformation and stability, it lacks sequence-specific DNA binding, a transactivation function and growth suppression. However, mutating T284-->R in the 273H p53-CD restores the DNA binding affinity, and transactivation and tumour suppressor functions. Since X-ray/NMR structures of DNA-free or DNA-bound mutant p53-CD molecules are unavailable, the factors governing the loss and rescue of sequence-specific DNA binding in the 273H and 273H+284R p53-CD, respectively, are unclear. Hence, we have carried out molecular dynamics (MD) simulations of the wild-type, single mutant and double mutant p53-CD, free and DNA bound, in the presence of explicit water molecules. Based on the MD structures, the DNA-binding free energy of each p53 molecule has been computed and decomposed into component energies and contributions from the interface residues. The wild-type and mutant p53-CD MD structures were found to be consistent with the antibody-binding, X-ray and NMR data. The predicted DNA binding affinity and specificity of both mutant p53-CDs were also in accord with experimental data. The non-detectable DNA binding of the 273H p53-CD is due mainly to the disruption of a hydrogen-bonding network involving R273, D281 and R280, leading to a loss of major groove binding by R280 and K120. The restoration of DNA binding affinity and specificity of the 273H+284R p53-CD is due mainly to the introduction of another DNA-binding site at position 284, leading to a recovery of major groove binding by R280 and K120. The important role of water molecules and the DNA major groove conformation as well as implications for structure-based linker rescue of the 273H p53-CD DNA-binding affinity are discussed.