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Endothelial Cells of the Lung
Published in Joan Gil, Models of Lung Disease, 2020
Another advantage of the cell culture approach is that pure populations of cells can be isolated and their individual cell products purified. These substances can then be used with other cell types found in the same organ to determine if one cell’s products affect the behavior of another different cell. For example, it is now known that there is signaling between smooth muscle and endothelial cells within the vessel wall. By isolating the products of one cell type and adding them to the culture medium of th other, considerable new information has been obtained about the interactions between these cells (Mecham et al., 1987). It is also possible to isolate large quantities of endothelial cell products by using innovative culture techniques. For example, substantial increases in the surface area available for cell growth can be provided by microcarrier beads (Davies, 1981), which make it possible to purity substantial quantities of cell products.
Methods to Study Endothelium-Dependent Responses
Published in Thomas F. Lüscher, Paul M. Vanhoutte, The Endothelium: Modulator of Cardiovascular Function, 2020
Thomas F. Lüscher, Paul M. Vanhoutte
The time for the perfusate to leave the arterial segment with endothelium and to reach the bioassay ring can be altered. This allows the estimation of the biological half-life of endothelium-derived vasoactive substances. The administration of drugs below the arterial segment with endothelium determines the direct effect on the bioassay ring, while that of drugs above the donor segment determines how the endothelial cells respond to it. Cultured endothelial cells seeded on microcarrier beads can also be used as a source of endothelial substances (see Section IV.C).
Strategies for Activation of Macrophages in Vivo for the Therapy of Metastatic Disease
Published in Gloria H. Heppner, Amy M. Fulton, Macrophages and Cancer, 2019
Richard Kirsh, William J. Johnson, Peter J. Bugelski, George Poste
Economic considerations such as this clearly suggest that other particulate microcarrier systems such as multiphase emulsions and biodegradable polymeric nanoparticles, which share many of the advantageous properties of liposomes, deserve careful evaluation. Prevailing commercial factors currently favor these alternative drug carriers because they can be produced as pharmaceutically acceptable formulations at far less cost than liposomes using existing equipment and manufacturing processes universally available within the pharmaceutical industry. In this regard, one emulsion-based drug delivery system containing diazapam is currently available commercially for parenteral use.
Process parameters of microsphere preparation based on propylene carbonate emulsion-precursors
Published in Journal of Microencapsulation, 2021
Microparticulate drug delivery systems are nowadays highly appreciated as versatile drug carriers, which can encapsulate both lipophilic (Birnbaum et al.2000, Allhenn and Lamprecht 2011) and hydrophilic (Ito et al.2007, Hales et al.2017) drug substances. In addition, these systems can be administered by different routes, often employing controllable drug release patterns (Birnbaum et al.2000, Park et al.2017, Garner et al.2018, Takeuchi et al.2018). Factors such as physicochemical properties of the matrix polymer, type of organic solvent or the manufacturing conditions are known to have a major impact on the final characteristics of microcarrier formulations (Blanco and Alonso 1998; Paillard-Giteau et al.2010). Subsequently, the microencapsulation of drug substances possesses many technological challenges related to different process parameters (Ito et al.2007, Feczkó et al.2008; Buske et al.2012).
Engineering mesenchymal stem cells to improve their exosome efficacy and yield for cell-free therapy
Published in Journal of Extracellular Vesicles, 2018
Jennifer Phan, Priyadarsini Kumar, Dake Hao, Kewa Gao, Diana Farmer, Aijun Wang
The microcarriers are tiny beads with many varying features such as material, pore size, and surface charge [53]. The cells, adhered on microcarriers, are grown in spinner flasks that hold a pair of plastic baffles in an X formation propelled by a magnetic field, creating a dynamic environment. The flasks also come in different sizes, ranging from 100 mL to 3 L and are placed on stir plates within an incubator where gas exchange occurs by either the loosened side caps or by a gas line through the holes on the side caps. Using this method, the final cell yield is quite high and can be achieved within a shorter incubation time. MSCs cultured using this method show no change in differentiation capability and maintain a normal karyotype [52–55]. The CM collected from the suspension culture was shown to contain higher levels of secretory molecules, which increased the cell proliferation and neural differentiation when injected directly to the hippocampal dentate gyrus of rat brains [55]. The CM also enhanced both the survival and differentiation rates of human neural precursor cells in culture [52]. A drawback to this method is that the cells are much more metabolically active, thus more nutrients are consumed, and more wastes are produced, requiring frequent change of culture media and passaging. Nevertheless, this could be one of the promising methods to increase MSC-exosomes production with less culture media.
Calcium-oligochitosan-pectin microcarrier for colonic drug delivery
Published in Pharmaceutical Development and Technology, 2020
Samuel Stealey, Xiaoru Guo, Rebecca Majewski, Alexander Dyble, Kendra Lehman, Michael Wedemeyer, Douglas A. Steeber, Matey G. Kaltchev, Junhong Chen, Wujie Zhang
Because CP microcarriers were not stable in simulated intestinal fluid, they would be poor candidates for colonic delivery. Therefore, COP-based microcarriers would be preferred for colonic drug delivery as they remain viable through incubation in the stomach and intestines before releasing their encapsulated contents in the colon.