Dealing with Missing Angular Sections in NanoCT Reconstructions of Low Contrast Polymeric Samples Employing a Mechanical In Situ Loading Stage.

While in situ experiments are gaining importance for the (mechanical) assessment of metamaterials or materials with complex microstructures, imaging conditions in such experiments are often challenging. The lab-based computed tomography system Xradia 810 Ultra allows for the in situ (time-lapsed) mechanical testing of samples. However, the in situ loading setup of this system limits the image acquisition angle to 140°.

Site-Selective Biofunctionalization of 3D Microstructures Via Direct Ink Writing.

Two-photon lithography has revolutionized multi-photon 3D laser printing, enabling precise fabrication of micro- and nanoscale structures. Despite many advancements, challenges still persist, particularly in biofunctionalization of 3D microstructures. This study introduces a novel approach combining two-photon lithography with scanning probe lithography for post-functionalization of 3D microstructures overcoming limitations in achieving spatially controlled biomolecule distribution.

Regulation of PD-L1 Trafficking from Synthesis to Degradation.

Programmed death-ligand 1 (PD-L1) is a transmembrane ligand for the programmed cell death protein 1 (PD-1), a receptor that inhibits T-cell activity. The PD-L1/PD-1 immune checkpoint axis has been successfully targeted to enhance antitumor immune responses. Tethering PD-L1 to the membrane spatially restricts its ability to inhibit immune responses, and it provides for the acute and reversible modulation of PD-L1 plasma membrane density by regulation of its trafficking.

Membrane remodelling triggers maturation of excitation-contraction coupling in 3D-shaped human-induced pluripotent stem cell-derived cardiomyocytes.

The prospective use of human-induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CM) for cardiac regenerative medicine strongly depends on the electro-mechanical properties of these cells, especially regarding the Ca-dependent excitation-contraction (EC) coupling mechanism. Currently, the immature structural and functional features of hiPSC-CM limit the progression towards clinical applications. Here, we show that a specific microarchitecture is essential for functional maturation of hiPSC-CM.

Proximity proteome mapping reveals PD-L1-dependent pathways disrupted by anti-PD-L1 antibody specifically in EGFR-mutant lung cancer cells.

Background: PD-L1, a transmembrane ligand for immune checkpoint receptor PD1, has been successfully targeted to activate an anti-tumor immune response in a variety of solid tumors, including non-small cell lung cancer (NSCLC). Despite the success of targeting PD-L1, only about 20% of patients achieve a durable response. The reasons for the heterogeneity in response are not understood, although some molecular subtypes (e.

Selective Positioning of Different Cell Types on 3D Scaffolds via DNA Hybridization.

Three-dimensional (3D) microscaffolds for cell biology have shown their potential in mimicking physiological environments and simulating complex multicellular constructs. However, controlling the localization of cells precisely on microfabricated structures is still complex and usually limited to two-dimensional assays. Indeed, the implementation of an efficient method to selectively target different cell types to specific regions of a 3D microscaffold would represent a decisive step toward cell-by-cell assembly of complex cellular arrangements.

Adaptation of cell spreading to varying fibronectin densities and topographies is facilitated by β1 integrins.

Cells mechanical behaviour in physiological environments is mediated by interactions with the extracellular matrix (ECM). In particular, cells can adapt their shape according to the availability of ECM proteins, e.g.

Physicochemical Properties and Biological Activities of Garlic ( L.) Bulb and Leek ( L. var) Leaf Oil Extracts.

species including garlic and leek exhibits a broad range of medicinal and nutritional properties. Therefore, this study investigates the physicochemical and biological activities of garlic ( L.) and leek ( L.

Intriguing Heteroleptic Zn bis(dipyrrinato) Emitters in the Far-Red Region With Large Pseudo-Stokes Shift for Bioimaging.

Novel heteroleptic Zn bis(dipyrrinato) complexes were prepared as intriguing emitters. With our tailor-made design, we achieved far-red emissive complexes with a photoluminescence quantum yield up to 45% in dimethylsulfoxide and 70% in toluene. This means that heteroleptic Zn bis(dipyrrinato) complexes retain very intense emission also in polar solvents, in contrast to their homoleptic counterparts, which we prepared for comparing the photophysical properties.

Micro-scaffolds as synthetic cell niches: recent advances and challenges.

Micro-fabrication and nano-fabrication provide useful approaches to address fundamental biological questions by mimicking the physiological microenvironment in which cells carry out their functions. In particular, 2D patterns and 3D scaffolds obtained via lithography, direct laser writing, and other techniques allow for shaping hydrogels, synthetic polymers and biologically derived materials to create structures for (single) cell culture. Applications of micro-scaffolds mimicking cell niches include stem cell self-renewal, differentiation, and lineage specification.

Coronary plaque composition influences biomechanical stress and predicts plaque rupture in a morpho-mechanic OCT analysis.

Plaque rupture occurs if stress within coronary lesions exceeds the protection exerted by the fibrous cap overlying the necrotic lipid core. However, very little is known about the biomechanical stress exerting this disrupting force. Employing optical coherence tomography (OCT), we generated plaque models and performed finite-element analysis to simulate stress distributions within the vessel wall in 10 ruptured and 10 non-ruptured lesions.

Mechanical stimulation of single cells by reversible host-guest interactions in 3D microscaffolds.

Many essential cellular processes are regulated by mechanical properties of their microenvironment. Here, we introduce stimuli-responsive composite scaffolds fabricated by three-dimensional (3D) laser lithography to simultaneously stretch large numbers of single cells in tailored 3D microenvironments. The key material is a stimuli-responsive photoresist containing cross-links formed by noncovalent, directional interactions between β-cyclodextrin (host) and adamantane (guest).

3D-microenvironments initiate TCF4 expression rescuing nuclear β-catenin activity in MCF-7 breast cancer cells.

Mechanical cues sensed by tumor cells in their microenvironment can influence important mechanisms including adhesion, invasion and proliferation. However, a common mechanosensitive protein and/or pathway can be regulated in different ways among diverse types of tumors. Of particular interest are human breast epithelial cancers, which markedly exhibit a heterogeneous pattern of nuclear β-catenin localization, a protein known to be involved in both mechanotransduction and tumorigenesis.

Intrinsic calcification angle: a novel feature of the vulnerable coronary plaque in patients with type 2 diabetes: an optical coherence tomography study.

Background: Coronary calcification is associated with high risk for cardiovascular events. However, its impact on plaque vulnerability is incompletely understood. In the present study we defined the intrinsic calcification angle (ICA) as the angle externally projected by a vascular calcification and analyzed its role as novel feature of coronary plaque vulnerability in patients with type 2 diabetes.

3D Scaffolds to Study Basic Cell Biology.

Mimicking the properties of the extracellular matrix is crucial for developing in vitro models of the physiological microenvironment of living cells. Among other techniques, 3D direct laser writing (DLW) has emerged as a promising technology for realizing tailored 3D scaffolds for cell biology studies. Here, results based on DLW addressing basic biological issues, e.

Studying Cell Mechanobiology in 3D: The Two-Photon Lithography Approach.

Two-photon lithography is a laser writing technique that can produce 3D microstructures with resolutions below the diffraction limit. This review focuses on its applications to study mechanical properties of cells, an emerging field known as mechanobiology. We review 3D structural designs and materials in the context of new experimental designs, including estimating forces exerted by single cells, studying selective adhesion on substrates, and creating 3D networks of cells.

Laser micromachining of tapered optical fibers for spatially selective control of neural activity.

Tapered and micro-structured optical fibers (TFs) recently emerged as a versatile tool to obtain dynamically addressable light delivery for optogenetic control of neural activity in the mammalian brain. Small apertures along a metal-coated and low-angle taper allow for controlling light delivery sites in the neural tissue by acting on the coupling angle of the light launched into the fiber. However, their realization is typically based on focused ion beam (FIB) milling, a high-resolution but time-consuming technique.

Single-cell-based evaluation of sperm progressive motility via fluorescent assessment of mitochondria membrane potential.

Sperm cells progressive motility is the most important parameter involved in the fertilization process. Sperm middle piece contains mitochondria, which play a critical role in energy production and whose proper operation ensures the reproductive success. Notably, sperm progressive motility is strictly related to mitochondrial membrane potential (MMP) and consequently to mitochondrial functionality.

Microenvironmental Stiffness of 3D Polymeric Structures to Study Invasive Rates of Cancer Cells.

Cells are highly dynamic elements, continuously interacting with the extracellular environment. Mechanical forces sensed and applied by cells are responsible for cellular adhesion, motility, and deformation, and are heavily involved in determining cancer spreading and metastasis formation. Cell/extracellular matrix interactions are commonly analyzed with the use of hydrogels and 3D microfabricated scaffolds.

Molecular typing and drug sensitivity testing of Mycobacterium tuberculosis isolated by a community-based survey in Ethiopia.

Background: The identification of circulating TB strains in the community and drug sensitivity patterns is essential for the tuberculosis control program. This study was undertaken to identify M. tuberculosis strains circulating in selected communities in Ethiopia as well as to evaluate the drug sensitivity pattern of these strains.

The first population-based national tuberculosis prevalence survey in Ethiopia, 2010-2011.

Setting: Tuberculosis (TB) remains a major public health problem in Ethiopia.

Objective: To determine the prevalence of pulmonary TB among the general adult population aged ≥15 years in 2010-2011. METHOD A nationwide, cluster-sampled, stratified (urban/rural/pastoralist), cross-sectional survey was conducted in 85 selected clusters.

Toxicity study and evaluation of biochemical markers towards the identification of the causative agent for an outbreak of liver disease in Tahtay Koraro Woreda, Tigray.

Background: A team of experts of the Faculty of Medicine, Addis Ababa University reported the emergence of unidentified fatal liver disease in Tahtay Koraro Woreda, Tigray in the mid of December 2005. The EHNRI has been then instructed to investigate the possible etiological agent that are likely to be responsible in triggering the health problem and a field survey team consisting of experts were went to the affected area to investigate the situations surrounding the disease.

Objectives: This investigation was conducted to determine the possible etiological agent(s) for the stated health problem in the affected village.

Training laboratory technicians from the Ethiopian periphery in the MODS technique enables rapid and low-cost diagnosis of Mycobacterium tuberculosis infection.

Tuberculosis (TB) is a leading cause of morbidity and mortality and is frequently complicated by emergence of drug-resistant strains. Diagnosis of TB in developing countries is often based on the relatively insensitive acid-fast staining that does not enable susceptibility profiling. Microscopic observation drug susceptibility assay (MODS) is an inexpensive, simple method that enables rapid TB culture coupled with susceptibility testing.

Improved tuberculosis smear detection in resource-limited settings: Combined bleach concentration and LED fluorescence microscopy.

Improved diagnostics for tuberculosis is a high priority in resource-limited settings (RLS). Sputum concentration and fluorescence microscopy (FM) are standard techniques in developed countries where appropriate biosafety precautions are possible. Recently, inexpensive fluorescent lenses using LED light sources have made auramine-based FM more feasible in RLS.