Expandable Lung Epithelium Differentiated from Human Embryonic Stem Cells

Using Polycaprolactone Nanofibers for the Proof-of-Concept Construction of the Alveolar-Capillary Interface

The alveolar-capillary interface is the key functional element of gas exchange in the human lung, and disruptions to this interface can lead to significant medical complications. However, it is currently challenging to adequately model this interface in vitro, as it requires not only the co-culture of human alveolar epithelial and endothelial cells but mainly the preparation of a biocompatible scaffold that mimics the basement membrane. This scaffold should support cell seeding from both sides, and maintain optimal cell adhesion, growth, and differentiation conditions. Our study investigates the use of polycaprolactone (PCL) nanofibers as a versatile substrate for such cell cultures, aiming to model the alveolar-capillary interface more accurately. We optimized nanofiber production parameters, utilized polyamide mesh UHELON as a mechanical support for scaffold handling, and created 3D-printed inserts for specialized co-cultures. Our findings confirm that PCL nanofibrous scaffolds are manageable and support the co-culture of diverse cell types, effectively enabling cell attachment, proliferation, and differentiation. Our research establishes a proof-of-concept model for the alveolar-capillary interface, offering significant potential for enhancing cell-based testing and advancing tissue-engineering applications that require specific nanofibrous matrices.

Pulsed laser ablation synthesis of fresh Te nanoparticles for matrix assisted laser desorption/ionization mass spectrometry (MALDI-MS) applications

This work aims to demonstrate the potential of pulsed laser ablation synthesis (PLA) of tellurium nanoparticles (Te NPs) for use in matrix assisted laser desorption/ionization mass spectrometry (MALDI-MS) applications. An experimental laboratory setup for PLA synthesis of fresh Te NPs was designed to prevent unwanted aggregation of uncoated Te NPs and avoid the need to use additional modifiers. Performing pulsed laser ablation synthesis in liquid (PLAL) using acetone was found to be the optimal way of preparing Te NPs. Another possibility is to use commercially available laser ablation devices for laser ablation - inductively coupled plasma mass spectrometry (LA-ICP-MS) to perform PLA in a helium atmosphere, but this approach is less efficient and results in the formation of unwanted larger particles. The prepared Te NPs were studied using the transmission electron microscopy (TEM) and dynamic light scattering (DLS) methods. TEM images showed the formation of Te NP nanochains composed of many crystallized Te NPs with sizes ranging from 8 to 15 nm. The various size distributions of the synthesized Te NPs identified using the DLS method correspond to the size distributions of aggregations rather than individual Te NPs. The synthesized Te NPs were used for a pilot study of their possible use with the MALDI-MS technique. An important effect was observed when Te NPs were used to perform a MALDI-MS analysis of the α-cyclodextrin (α-CD) and cucurbit[7]uril (CB7) macrocycles, which consisted in a decline in the formation of matrix adducts. Furthermore, several changes in MALDI-MS mass spectra of intact cells and a positive effect of Te NPs on the crystallization of the MALDI-MS matrix were observed.

Intact cell mass spectrometry coupled with machine learning reveals minute changes induced by single gene silencing

Intact (whole) cell MALDI TOF mass spectrometry is a commonly used tool in clinical microbiology for several decades. Recently it was introduced to analysis of eukaryotic cells, including cancer and stem cells. Besides targeted metabolomic and proteomic applications, the intact cell MALDI TOF mass spectrometry provides a sufficient sensitivity and specificity to discriminate cell types, isogenous cell lines or even the metabolic states. This makes the intact cell MALDI TOF mass spectrometry a promising tool for quality control in advanced cell cultures with a potential to reveal batch-to-batch variation, aberrant clones, or unwanted shifts in cell phenotype. However, cellular alterations induced by change in expression of a single gene has not been addressed by intact cell mass spectrometry yet. In this work we used a well-characterized human ovarian cancer cell line SKOV3 with silenced expression of a tumor suppressor candidate 3 gene (TUSC3). TUSC3 is involved in co-translational N-glycosylation of proteins with well-known global impact on cell phenotype. Altogether, this experimental design represents a highly suitable model for optimization of intact cell mass spectrometry and analysis of spectral data. Here we investigated five machine learning algorithms (k-nearest neighbors, decision tree, random forest, partial least squares discrimination, and artificial neural network) and optimized their performance either in pure populations or in two-component mixtures composed of cells with normal or silenced expression of TUSC3. All five algorithms reached accuracy over 90 % and were able to reveal even subtle changes in mass spectra corresponding to alterations of TUSC3 expression. In summary, we demonstrate that spectral fingerprints generated by intact cell MALDI-TOF mass spectrometry coupled to a machine learning classifier can reveal minute changes induced by alteration of a single gene, and therefore contribute to the portfolio of quality control applications in routine cell and tissue cultures.

Advanced lung organoids for respiratory system and pulmonary disease modeling

Amidst the recent coronavirus disease 2019 (COVID-19) pandemic, respiratory system research has made remarkable progress, particularly focusing on infectious diseases. Lung organoid, a miniaturized structure recapitulating lung tissue, has gained global attention because of its advantages over other conventional models such as two-dimensional (2D) cell models and animal models. Nevertheless, lung organoids still face limitations concerning heterogeneity, complexity, and maturity compared to the native lung tissue. To address these limitations, researchers have employed co-culture methods with various cell types including endothelial cells, mesenchymal cells, and immune cells, and incorporated bioengineering platforms such as air-liquid interfaces, microfluidic chips, and functional hydrogels. These advancements have facilitated applications of lung organoids to studies of pulmonary diseases, providing insights into disease mechanisms and potential treatments. This review introduces recent progress in the production methods of lung organoids, strategies for improving maturity, functionality, and complexity of organoids, and their application in disease modeling, including respiratory infection and pulmonary fibrosis.