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Self‐assembling peptides (SAPs) are versatile building blocks in the creation of hierarchical nanostructures. Although SAPs promise precise control over assembled morphology and dimensions, experimental validation is still crucial. In this sense, recent efforts have focused on nanospiral structures, which mimic natural architectures and hold potential for biomedical and nanotechnological applications. Here, it is demonstrated that SARS‐CoV‐2 fusion peptides are able to form specific spiral‐like structures using interfacial assembly as a fabrication methodology, along with fine‐tuning of the spiral ensembles through an imposed interfacial flow due to the uniaxial compression in a Langmuir–Blodgett trough. Molecular characterization by atomic force microscopy, neutron reflectometry, interfacial shear rheology, and infrared spectroscopy, highlighted how variations in fusion peptide sequences influence assembly, highlighting the importance of molecular design. These spiral structures are subsequently modified to serve as templates for metallic replicas, expanding the potential of peptide‐guided self‐assembly in fabricating tailored nanostructured surfaces with sub‐10 nm dimensions over cm2 areas. [ABSTRACT FROM AUTHOR]

A characteristic new cooperative dehydration transition, in 1:1 Laponite-MMT cogel, was observed at Tc ≈ 60 °C, a temperature at which the storage modulus (G′) and depolarization ratio (Dp) showed sharp increase, and the isotropic cogel turned into an anisotropic one. The dehydration dynamics could be described through power-law relations: G′ ∼ (Tc - T)-γ and Dp ∼ (Tc - T)-β with γ ≈ β = 0.40 ± 0.05. The x-ray diffraction data revealed that the crystallite size decreased from 17 nm (at 20 °C) to 10 nm (at 80 °C) implying loss of free and inter-planar water. When this cogel was spontaneously cooled below Tc, it exhibited much larger storage modulii values which implied the existence of several metastable states in this system. This phase transition could be modeled through Landau theory, where the depolarization ratio was used as experimental order parameter (ψ). This parameter was found to scale with temperature, as ψ ∼ (Tc - T)-α, with power-law exponent α = 0.40 ± 0.05; interestingly, we found α ≈ β ≈ γ. [ABSTRACT FROM AUTHOR]

Binding of nanoclay (Laponite) to gelatin-A and gelatin-B (both polyampholytes) molecules was investigated at room temperature (25 °C) both experimentally and theoretically. The stoichiometric binding ratio between gelatin and Laponite was found to be strongly dependent on the solution ionic strength. Large soluble complexes were formed at higher ionic strengths of the solution, a result supported by data obtained from light scattering, viscosity, and zeta potential measurements. The binding problem was theoretically modeled by choosing a suitable two-body screened Coulomb potential, U(R+)=(q-/2[variant_greek_epsilon])[(Q-/R-)e-kR--(Q+/R+)e-kR+], where the protein dipole has charges Q+ and Q_ that are located at distances R+ and R_ from the point Laponite charge q- and the dispersion liquid has dielectric constant ([variant_greek_epsilon]). U(R+) accounted for electrostatic interactions between a dipole (protein molecule) and an effective charge (Laponite particle) located at an angular position θ. Gelatin-A and Laponite association was facilitated by a strong attractive interaction potential that led to preferential binding of the biopolymer chains to negatively charged face of Laponite particles. In the case of gelatin-B selective surf ace patch binding dominated the process where the positively charged rim and negatively charged face of the particles were selectively bound to the oppositely charged segments of the biopolymer. The equilibrium separation (Re) between the protein and nanoclay particle revealed monovalent salt concentration dependence given by Re∼[NaCl]α where α=0.6±0.2 for gelatin-A and α=0.4±0.2 for gelatin-B systems. The equilibrium separations were ≈30% less compared to the gelatin-A system implying preferential short-range ordering of the gelatin-B–nanoclay pair in the solvent. [ABSTRACT FROM AUTHOR]

The transmembrane serine protease matriptase is a key regulator of both barrier-disruptive and protective epithelial cell-cell interactions. Elevated matriptase is a consistent feature of epithelial ovarian cancers (OvCa), where multicellular spheroids shed from the primary tumor into the peritoneal cavity are critical drivers of metastasis. Dynamic cell-to-cell adhesive contacts are required for spheroid formation and maintenance. Here, we show that overactive matriptase, reflected in an increased ratio of matriptase to its inhibitor hepatocyte growth factor activator inhibitor 1 (HAI-1), disrupts cell-cell contacts to produce loose prometastatic spheroids that display increased mesothelial cell adhesion and submesothelial invasion. We show that these activities are dependent on the matriptase activation of a protease-activated receptor-2 (PAR-2) signaling pathway involving PI3K/Akt and MMP9-induced disruption of cell-cell adhesion by the release of the soluble E-cadherin ectodomain. These data reveal a novel pathological connection between matriptase activation of PAR-2 and disruption of cell-cell adhesion, and support the clinical investigation of this signaling axis as a therapeutic strategy for aggressive metastatic OvCa., (© 2023 Pawar et al.)

Background: At 140 million, India has the second largest population of old people in the world, as per the 2011 census.1 The covid 19 pandemic has wreaked havoc in millions of lives. Elderly are especially vulnerable to COVID-19 and experience high morbidity and mortality as a result of immunosenescence. Age is independently linked with mortality, but age alone does not adequately capture the robustness of older adults who are a heterogeneous group. The current research was done in a tertiary healthcare hospital in Maharashtra to understand the clinical profile and factors that affected the outcome of elderly during the second wave of the COVID pandemic., Method: This was a single centre retrospective observational study done in a tertiary hospital which was admitting both covid and non-covid patients during the time of this study. All elderly patients admitted with COVID 19 disease in Covid ward and covid ICU (Intensive care unit) were included in the study. Their Demographic details, duration of illness, vital parameters, oxygen saturation, partial pressure of arterial oxygen compared to fraction of inspired oxygen (PaO2-FiO2 ratio) were recorded and also relevant investigations such as complete blood count, kidney function tests, liver function tests, arterial blood gases, chest X-rayand ECG (Electrocardiogram),CT scan of the brain, CSF(cerebrospinal fluid) studies and other tests where relevant were recorded. Inflammatory markers such as C-Reactive Protein (CRP), Ferritin, D-Dimer and Chest CT scan were noted. Clinical profiles and outcomes were noted till discharge or death., Results: Among 231 patients that were included in this study, 81(35%) were female and 150 (65%) were male. Ninety-two patients died (39.8%) while 139 patients (60.2%) survived in our study. Majority of our patients (211;91.3%) presented in category E(pneumonia with respiratory failure) or category F(pneumonia with respiratory failure and multiorgan dysfunction syndrome). Factors which had a major impact on mortality were- a low PaO2-FiO2 ratio on admission, high C-Reactive Protein (CRP) levels, high d-dimer levels, a finding of bilateral ground glass opacities on x-ray, and need for invasive ventilation on admission., Conclusions: Elderly remain vulnerable to severe consequences of COVID-19 infection owing to the increasing comorbidities and immunosenescence in them. Prolonged oxygen therapy and intensive respiratory rehabilitation are the mainstays of effective management. Given the constant threat of mutating virus, masking, maintaining hand sanitization, vaccination and also caring for our elders while still maintaining social distance are our best bet against a fatal third wave., (© Journal of the Association of Physicians of India 2011.)