Non-invasive in vitro NAM for the detection of reversible and irreversible eye damage after chemical exposure for GHS classification purposes (ImAi).

The potential risk of chemicals to the human eye is assessed by adopted test guidelines (TGs) for regulatory purposes to ensure consumer safety. Over the past decade, the Organization for Economic Co-operation and Development (OECD) has approved new approach methodologies (NAMs) to predict chemical eye damage. However, existing NAMs remain associated with limitations: First, no full replacement of the in vivo Draize eye test due to limited predictability of severe/mild damage was reached.

The Impact of NO on Epithelial Barrier Integrity of a Primary Cell-Based Air-Liquid Interface Model of the Nasal Respiratory Epithelium.

Nitrogen dioxide (NO) is a pervasive gaseous air pollutant with well-documented hazardous effects on health, necessitating precise toxicological characterization. While prior research has primarily focused on lower airway structures, the upper airways, serving as the first line of defense against airborne substances, remain understudied. This study aimed to investigate the functional effects of NO exposure alone or in combination with hypoxia as a secondary stimulus on nasal epithelium and elucidate its molecular mechanisms because hypoxia is considered a pathophysiological factor in the onset and persistence of chronic rhinosinusitis, a disease of the upper airways.

Impedance-based in vitro eye irritation testing enables the categorization of diluted chemicals.

Products containing chemicals with eye irritation potential need to be labeled with the respective hazard symbol. To avoid the testing of numerous dilutions of chemicals on animals, their labeling is directed by a theoretical approach. In this report, a previously described in vitro tissue model of the cornea based on human epithelial cells was used for eye irritation testing of dilutions.

Characterization of an iPSC-based barrier model for blood-brain barrier investigations using the SBAD0201 stem cell line.

Background: Blood-brain barrier (BBB) models based on primary murine, bovine, and porcine brain capillary endothelial cell cultures have long been regarded as robust models with appropriate properties to examine the functional transport of small molecules. However, species differences sometimes complicate translating results from these models to human settings. During the last decade, brain capillary endothelial-like cells (BCECs) have been generated from stem cell sources to model the human BBB in vitro.

Subcellular trafficking and transcytosis efficacy of different receptor types for therapeutic antibody delivery at the blood‒brain barrier.

Here, we report an experimental setup to benchmark different receptors for targeted therapeutic antibody delivery at the blood-brain barrier. We used brain capillary endothelial-like cells derived from induced pluripotent stem cells (hiPSC-BECs) as a model system and compared them to colon epithelial Caco-2 cells. This approach helped to identify favourable receptors for transport into the cell layer itself or for directing transport for transcytosis across the cell layer.

Human isogenic cells of the neurovascular unit exert transcriptomic cell type-specific effects on a blood-brain barrier in vitro model of late-onset Alzheimer disease.

Background: The function of the blood-brain barrier (BBB) is impaired in late-onset Alzheimer disease (LOAD), but the associated molecular mechanisms, particularly with respect to the high-risk APOE4/4 genotype, are not well understood. For this purpose, we developed a multicellular isogenic model of the neurovascular unit (NVU) based on human induced pluripotent stem cells.

Methods: The human NVU was modeled in vitro using isogenic co-cultures of astrocytes, brain capillary endothelial-like cells (BCECs), microglia-like cells, neural stem cells (NSCs), and pericytes.

Locked Out: Phoenixin-14 Does Not Cross a Stem-Cell-Derived Blood-Brain Barrier Model.

Phoenixin-14 is a recently discovered peptide regulating appetite. Interestingly, it is expressed in the gastrointestinal tract; however, its supposed receptor, GPR173, is predominantly found in hypothalamic areas. To date, it is unknown how peripherally secreted phoenixin-14 is able to reach its centrally located receptor.

Full thickness 3D in vitro conjunctiva model enables goblet cell differentiation.

In vitro culture and generation of highly specialized goblet cells is still a major challenge in conjunctival 3D in vitro equivalents. A model comprising all physiological factors, including mucus-secreting goblet cells has the potential to act as a new platform for studies on conjunctival diseases. We isolated primary conjunctival epithelial cells and fibroblasts from human biopsies.

Overcoming the blood-brain barrier? - prediction of blood-brain permeability of hydrophobically modified polyethylenimine polyplexes for siRNA delivery into the brain with in vitro and in vivo models.

The blood-brain barrier (BBB) is a highly selective biological barrier that represents a major bottleneck in the treatment of all types of central nervous system (CNS) disorders. Small interfering RNA (siRNA) offers in principle a promising therapeutic approach, e.g.

A primary cell-based model of the human small intestine reveals host olfactomedin 4 induction in response to Typhimurium infection.

Infection research largely relies on classical cell culture or mouse models. Despite having delivered invaluable insights into host-pathogen interactions, both have limitations in translating mechanistic principles to human pathologies. Alternatives can be derived from modern Tissue Engineering approaches, allowing the reconstruction of functional tissue models .

In Model, In Vitro and In Vivo Killing Efficacy of Antitumor Peptide RDP22 on MUG-Mel2, a Patient Derived Cell Line of an Aggressive Melanoma Metastasis.

The host defense derived peptide was assessed in different model systems with increasing complexity employing the highly aggressive NRAS mutated melanoma metastases cell line MUG-Mel2. Amongst others, fluorescence microscopy and spectroscopy, as well as cell death studies were applied for liposomal, 2D and 3D in vitro models including tumor spheroids without or within skin models and in vivo mouse xenografts. Summarized, MUG-Mel2 cells were shown to significantly expose the negatively charged lipid phosphatidylserine on their plasma membranes, showing they are successfully targeted by RDP22.

Sol-Gel-Derived Fibers Based on Amorphous -Hydroxy-Carboxylate-Modified Titanium(IV) Oxide as a 3-Dimensional Scaffold.

The development of novel fibrous biomaterials and further processing of medical devices is still challenging. For instance, titanium(IV) oxide is a well-established biocompatible material, and the synthesis of TiO particles and coatings via the sol-gel process has frequently been published. However, synthesis protocols of sol-gel-derived TiO fibers are hardly known.

Cell Adhesion Assessment Reveals a Higher Force per Contact Area on Fibrous Structures Compared to Flat Substrates.

The distribution and density of ligands have a determinant role in cell adhesion on planar substrates. At the same time, planar surfaces are nonphysiological for most cells, and cell behavior on planar and topographical surfaces is significantly different, with fibrous structures being the most natural environment for cells. Despite phenomenological examinations, the role of adhesion ligand density in the fibrous scaffold for cell adhesion strength has so far not been assessed.

The blood-brain barrier is dysregulated in COVID-19 and serves as a CNS entry route for SARS-CoV-2.

Neurological complications are common in COVID-19. Although SARS-CoV-2 has been detected in patients' brain tissues, its entry routes and resulting consequences are not well understood. Here, we show a pronounced upregulation of interferon signaling pathways of the neurovascular unit in fatal COVID-19.

From Single Batch to Mass Production-Automated Platform Design Concept for a Phase II Clinical Trial Tissue Engineered Cartilage Product.

Advanced Therapy Medicinal Products (ATMP) provide promising treatment options particularly for unmet clinical needs, such as progressive and chronic diseases where currently no satisfying treatment exists. Especially from the ATMP subclass of Tissue Engineered Products (TEPs), only a few have yet been translated from an academic setting to clinic and beyond. A reason for low numbers of TEPs in current clinical trials and one main key hurdle for TEPs is the cost and labor-intensive manufacturing process.

Measurements of transepithelial electrical resistance (TEER) are affected by junctional length in immature epithelial monolayers.

The measurement of transepithelial electrical resistance (TEER) is a common technique to determine the barrier integrity of epithelial cell monolayers. However, it is remarkable that absolute TEER values of similar cell types cultured under comparable conditions show an immense heterogeneity. Based on previous observations, we hypothesized that the heterogeneity of absolute TEER measurements can not only be explained by maturation of junctional proteins but rather by dynamics in the absolute length of cell junctions within monolayers.

Protein Kinase D2 drives chylomicron-mediated lipid transport in the intestine and promotes obesity.

Lipids are the most energy-dense components of the diet, and their overconsumption promotes obesity and diabetes. Dietary fat content has been linked to the lipid processing activity by the intestine and its overall capacity to absorb triglycerides (TG). However, the signaling cascades driving intestinal lipid absorption in response to elevated dietary fat are largely unknown.

Assessment of Human Health Risks Posed by Nano-and Microplastics Is Currently Not Feasible.

The exposure of humans to nano-and microplastic particles (NMPs) is an issue recognized as a potential health hazard by scientists, authorities, politics, non-governmental organizations and the general public. The concentration of NMPs in the environment is increasing concomitantly with global plastic production and the usage of plastic materials. NMPs are detectable in numerous aquatic organisms and also in human samples, therefore necessitating a risk assessment of NMPs for human health.

Human iPSC-Derived Blood-Brain Barrier Models: Valuable Tools for Preclinical Drug Discovery and Development?

Translating basic biological knowledge into applications remains a key issue for effectively tackling neurodegenerative, neuroinflammatory, or neuroendocrine disorders. Efficient delivery of therapeutics across the neuroprotective blood-brain barrier (BBB) still poses a demanding challenge for drug development targeting central nervous system diseases. Validated in vitro models of the BBB could facilitate effective testing of drug candidates targeting the brain early in the drug discovery process during lead generation.

Regulatory-Compliant Validation of a Highly Sensitive qPCR for Biodistribution Assessment of Hemophilia A Patient Cells.

The investigation of the biodistribution profile of a cell-based medicinal product is a pivotal prerequisite to allow a factual benefit-risk assessment within the non-clinical to clinical translation in product development. Here, a qPCR-based method to determine the amount of human DNA in mouse DNA was validated according to the guidelines of the European Medicines Agency and the International Council for Harmonisation of Technical Requirements for Pharmaceuticals for Human Use. Furthermore, a preclinical worst-case scenario study was performed in which this method was applied to investigate the biodistribution of 2 × 10 intravenously administered, genetically modified, blood outgrowth endothelial cells from hemophilia A patients after 24 h and 7 days.

Sterubin: Enantioresolution and Configurational Stability, Enantiomeric Purity in Nature, and Neuroprotective Activity in Vitro and in Vivo.

Alzheimer's disease (AD) is a neurological disorder with still no preventive or curative treatment. Flavonoids are phytochemicals with potential therapeutic value. Previous studies described the flavanone sterubin isolated from the Californian plant Eriodictyon californicum as a potent neuroprotectant in several in vitro assays.

Blood-Brain Barrier Permeability and Cytotoxicity of an Atorvastatin-Loaded Nanoformulation Against Glioblastoma in 2D and 3D Models.

Inhibitors of 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase of the family of statins have been suggested as therapeutic options in various tumors. Atorvastatin is a statin with the potential to cross the blood-brain barrier; however, the concentrations necessary for a cytotoxic effect against cancer cells exceed the concentrations achievable via oral administration, which made the development of a novel atorvastatin formulation necessary. We characterized the drug loading and basic physicochemical characteristics of micellar atorvastatin formulations and tested their cytotoxicity against a panel of different glioblastoma cell lines.

Bacterial nanocellulose as novel carrier for intestinal epithelial cells in drug delivery studies.

Synthetic cell carriers (A) represent common scaffold structures for the development of cell-based in vitro models of the human intestine but due to their low porosity or unwanted molecular adhesion effects, synthetic carriers can negatively affect cell function. Alternative scaffolds such as natural extracellular matrices (ECMs) (B) were shown to overcome some of the common drawbacks. However, their fabrication is time-consuming, less well standardized and not entirely conform to the 3R principle (replacement, reduction, refinement).