Selection of the Most Suitable Culture Medium for Patient-Derived Lung Cancer Organoids.

Introduction Patient-derived organoids have emerged as a promising in vitro model for precision medicine, particularly in cancer, but also in non-cancer-related diseases. However, the optimal culture medium for culturing patient-derived lung organoids has not yet been agreed upon. This study aimed to shed light on the optimal selection of a culture media for developing studies using patient-derived lung organoids. Methods Tumor and normal paired tissue from 71 resected non-small cell lung cancer patients were processed for organoid culture. Lung cancer organoids (LCOs) were derived from tumor tissue and normal lung organoids (LNOs) from non-neoplastic lung tissue. Three different culture media were compared: Permissive culture medium (PCM); Limited culture medium (LCM); and Minimum basal medium (MBM). We assessed their effectiveness in establishing organoid cultures, promoting organoid growth and viability, and compared their differential phenotypic characteristics. Results While PCM was associated with the highest success rate and useful for long-term expansion, MBM was the best option to avoid normal organoid overgrowth in the organoid culture. The density, size, and viability of LNOs organoids were reduced using LCM and severely affected with MBM. LNOs cultured in PCM tend to differentiate to bronchospheres, while alveolosphere differentiation can be observed in those cultured with LCM. The morphological phenotype of LCO was influenced by the culture media of election. Mesenchymal cell overgrowth was observed when LCM was used. Conclusion This work highlights the importance of considering the research objectives when selecting the most suitable culture medium for growing patient-derived lung organoids.

Corrosion Induced on Aluminum by Biodiesel Components in Non-Oxygen Environments.

Biodiesel is a mixture of saturated and unsaturated Fatty Acid Methyl Esters (FAMEs) whose composition affects the corrosion behavior of metal containers during storage. This study examines the effect of the C=C bond present in selected FAMEs (Methyl Stearate, Methyl Oleate, and Methyl Linoleate) in aluminum corrosion in the absence of oxygen. First, mass loss assays were carried out at 100, 200, and 280 °C for 1000 h using pure Methyl Stearate (MS), 5% Methyl Oleate in Methyl Stearate (MS-5% MO), and 5% Methyl Linoleate in Methyl Stearate (MS-5% ML). Next, chemical changes in FAMEs were studied using FTIR, TGA, and GC/MS. SEM/EDS analysis allowed us to inspect the aluminum surfaces and their chemical characterization. We estimated higher corrosion rates for MS assays than those of unsaturated methyl ester mixtures. In a separate set of experiments, we used electrochemical techniques (potentiodynamic polarization, linear polarization resistance, and electrochemical impedance spectroscopy) to investigate aluminum corrosion induced by thermal-degraded products from FAMEs at 100, 200, and 280 °C for 300 h able to dissolve in aqueous extracts. These electrochemical experiments revealed that the products in the aqueous extracts from the unsaturated methyl ester mixture form a passive layer on the Al surface thicker than pure MS at the corresponding degradation temperatures.