We have characterized some of the physiology of multicellular spheroids of different sizes grown from Chinese hamster lung fibroblast (V79) cells. Among the parameters studied were oxygen tension distributions within the spheroid. This was achieved using ultramicroelectrodes with tip diameters of 1-5 mu and a perfusion system whereby environmental conditions such as flow, temperature, and chemical makeup of the milieu could be measured and controlled. Plateau pO2 values of less than 10 mm Hg were consistently obtained from spheroids under various conditions. We were able to modify these distributions by use of indirect radiation sensitizer drugs such as mechlorethamine HCl (mustargen) at nontoxic doses. We have also made determinations of the inhibitory capacities of several other drugs on the respiration rate of constituent cells of multicellular spheroids in single-cell suspensions. We have concluded that there are indeed hypoxic cells in spheroids whose radioresistance may be modified by essentially nontoxic levels of indirect radiosensitizer drugs and that the system described shows great promise for screening agents which may modify radiation response.
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Methods Cell Biol
January 2025
Department of Oncology-Pathology, Karolinska Institutet, Solna, Sweden. Electronic address:
In recent years, three-dimensional (3D) cultures of tumor cells has emerged as an important tool in cancer research. The significance of 3D cultures, such as tumor spheroids, lies in their ability to mimic the in vivo tumor microenvironment more precisely, offering a nuanced understanding of immune responses within the context of tumor progression. In fact, the infiltration of cytotoxic lymphocytes is key to determining patients' prognosis in several types of cancer and response to immunotherapy.
View Article and Find Full Text PDFSci Adv
January 2025
Department of Bioengineering, University of Pennsylvania, Philadelphia, PA 19104, USA.
Tissues form during development through mechanical compaction of their extracellular matrix (ECM) and shape morphing, processes that result in complex-shaped structures that contribute to tissue function. While observed in vivo, control over these processes in vitro to understand both tissue development and guide tissue formation has remained challenging. Here, we use combinations of mesenchymal stromal cell spheroids and hydrogel microparticles (microgels) with varied hydrolytic stability to fabricate programmable and dynamic granular composites that control compaction and tissue formation over time.
View Article and Find Full Text PDFMethods Mol Biol
January 2025
Department of Internal Medicine II, University Hospital Frankfurt, Goethe University Frankfurt, Frankfurt am Main, Germany.
Spheroid culture systems have been extensively used to model the three-dimensional (3D) behavior of cells in vitro. Traditionally, spheroids consist of a single cell type, limiting their ability to fully recapitulate the complex inter-cellular interactions observed in vivo. Here we describe a protocol for generating cocultured spheroids composed of two distinct cell types, embedded within a 3D extracellular matrix (ECM) to better study cellular interactions.
View Article and Find Full Text PDFNat Methods
January 2025
Novo Nordisk Foundation Center for Protein Research, University of Copenhagen, Copenhagen, Denmark.
Single-cell proteomics (SCP) promises to revolutionize biomedicine by providing an unparalleled view of the proteome in individual cells. Here, we present a high-sensitivity SCP workflow named Chip-Tip, identifying >5,000 proteins in individual HeLa cells. It also facilitated direct detection of post-translational modifications in single cells, making the need for specific post-translational modification-enrichment unnecessary.
View Article and Find Full Text PDFACS Appl Bio Mater
January 2025
Koç University Translational Medicine Research Center, Koç University, Istanbul 34450, Turkey.
There is growing interest in generating in vitro models of tissues and tissue-related diseases to mimic normal tissue organization and pathogenesis for different purposes. The retina is a highly complex multicellular tissue where the organization of the cellular components relative to each other is critical for retinal function. Many retinopathies arise due to the disruption of this order.
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