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Technical Feasibility and Physiological Relevance of Hypoxic Cell Culture Models

. 2020 ; 11 () : 57. [epub] 20200221

Language English Country Switzerland Media electronic-ecollection

Document type Journal Article, Research Support, Non-U.S. Gov't, Review

Hypoxia is characterized as insufficient oxygen delivery to tissues and cells in the body and is prevalent in many human physiology processes and diseases. Thus, it is an attractive state to experimentally study to understand its inner mechanisms as well as to develop and test therapies against pathological conditions related to hypoxia. Animal models in vivo fail to recapitulate some of the key hallmarks of human physiology, which leads to human cell cultures; however, they are prone to bias, namely when pericellular oxygen concentration (partial pressure) does not respect oxygen dynamics in vivo. A search of the current literature on the topic revealed this was the case for many original studies pertaining to experimental models of hypoxia in vitro. Therefore, in this review, we present evidence mandating for the close control of oxygen levels in cell culture models of hypoxia. First, we discuss the basic physical laws required for understanding the oxygen dynamics in vitro, most notably the limited diffusion through a liquid medium that hampers the oxygenation of cells in conventional cultures. We then summarize up-to-date knowledge of techniques that help standardize the culture environment in a replicable fashion by increasing oxygen delivery to the cells and measuring pericellular levels. We also discuss how these tools may be applied to model both constant and intermittent hypoxia in a physiologically relevant manner, considering known values of partial pressure of tissue normoxia and hypoxia in vivo, compared to conventional cultures incubated at rigid oxygen pressure. Attention is given to the potential influence of three-dimensional tissue cultures and hypercapnia management on these models. Finally, we discuss the implications of these concepts for cell cultures, which try to emulate tissue normoxia, and conclude that the maintenance of precise oxygen levels is important in any cell culture setting.

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Mulkidjanian AY, Koonin EV, Makarova KS, Mekhedov SL, Sorokin A, Wolf YI, et al. . The cyanobacterial genome core and the origin of photosynthesis. Proc Natl Acad Sci USA. 103:13126–31. 10.1073/pnas.0605709103 PubMed DOI PMC

Canfield DE. The early history of atmospheric oxygen: homage to Robert M. Garrels. Annu Rev Earth Planet Sci. (2005) 33:1–36. 10.1146/annurev.earth.33.092203.122711 DOI

Hsia CCW, Schmitz A, Lambertz M, Perry SF, Maina JN. Evolution of air breathing: oxygen homeostasis and the transitions from water to land and sky. Compr. Physiol. (2013) 3:849–915. 10.1002/cphy.c120003 PubMed DOI PMC

Carreau A, Hafny-Rahbi BE, Matejuk A, Grillon C, Kieda C. Why is the partial oxygen pressure of human tissues a crucial parameter? Small molecules and hypoxia. J Cell Mol Med. (2011) 15:1239–53. 10.1111/j.1582-4934.2011.01258.x PubMed DOI PMC

Jamshidi N, Palsson B. Systems biology of the human red blood cell. Blood Cells Mol Dis. (2006) 36:239–47. 10.1016/j.bcmd.2006.01.006 PubMed DOI

Favier FB, Britto FA, Freyssenet DG, Bigard XA, Benoit H. HIF-1-driven skeletal muscle adaptations to chronic hypoxia: molecular insights into muscle physiology. Cell Mol Life Sci. (2015) 72:4681–96. 10.1007/s00018-015-2025-9 PubMed DOI PMC

Conkin J, Wessel JH. Critique of the equivalent air altitude model. Aviat Space Environ Med. (2008) 79:975–82. 10.3357/ASEM.2331.2008 PubMed DOI

Coppel J, Hennis P, Gilbert-Kawai E, Grocott MP. The physiological effects of hypobaric hypoxia versus normobaric hypoxia: a systematic review of crossover trials. Extrem Physiol Med. (2015) 4:2. 10.1186/s13728-014-0021-6 PubMed DOI PMC

Zhuan B, Yu Y, Yang Z, Zhao X, Li P. Mechanisms of oxidative stress effects of the NADPH oxidase-ROS-NF-κB transduction pathway and VPO1 on patients with chronic obstructive pulmonary disease combined with pulmonary hypertension. Eur Rev Med Pharmacol Sci. (2017) 21:3459–64. PubMed

Ostadal P, Mlcek M, Strunina S, Hrachovina M, Kruger A, Vondrakova D, et al. . Novel porcine model of acute severe cardiogenic shock developed by upper-body hypoxia. Physiol Res. (2016) 65:711–5. PubMed

Morita Y, Chin-Yee I, Yu P, Sibbald WJ, Martin CM. Critical oxygen delivery in conscious septic rats under stagnant or anemic hypoxia. Am J Respir Crit Care Med. (2003) 167:868–72. 10.1164/rccm.200205-490OC PubMed DOI

Lévy P, Kohler M, McNicholas WT, Barbé F, McEvoy RD, Somers VK, et al. . Obstructive sleep apnoea syndrome. Nat Rev Dis Prim. (2015) 1:15015. 10.1038/nrdp.2015.24 PubMed DOI

Benjamin JS, Culpepper CB, Brown LD, Wesolowski SR, Jonker SS, Davis MA, et al. . Chronic anemic hypoxemia attenuates glucose-stimulated insulin secretion in fetal sheep. Am J Physiol Integr Comp Physiol. (2017) 312:R492–500. 10.1152/ajpregu.00484.2016 PubMed DOI PMC

Kizaka-Kondoh S, Kuchimaru T, Kadonosono T. Pathophysiological response to hypoxia — from the molecular mechanisms of malady to drug discovery: hypoxia-inducible factor-1 (HIF-1)-active cells as a target for cancer therapy. J Pharmacol Sci. (2011) 115:440–5. 10.1254/jphs.10R20FM PubMed DOI

Jaroch K, Jaroch A, Bojko B. Cell cultures in drug discovery and development: the need of reliable in vitro-in vivo extrapolation for pharmacodynamics and pharmacokinetics assessment. J Pharm Biomed Anal. (2018) 147:297–312. 10.1016/j.jpba.2017.07.023 PubMed DOI

Jedrzejczak-Silicka M. History of cell culture. In: Gowder SJT. editor. New Insights Into Cell Culture Technology. London: InTech; (2017). p. 43936.

Metzen E, Wolff M, Fandrey J, Jelkmann W. Pericellular PO2 and O2 consumption in monolayer cell cultures. Respir Physiol. (1995) 100:101–6. 10.1016/0034-5687(94)00125-J PubMed DOI

Pettersen EO, Larsen LH, Ramsing NB, Ebbesen P. Pericellular oxygen depletion during ordinary tissue culturing, measured with oxygen microsensors. Cell Prolif . (2005) 38:257–67. 10.1111/j.1365-2184.2005.00345.x PubMed DOI PMC

Allen CB, Schneider BK, White CW. Limitations to oxygen diffusion and equilibration in in vitro cell exposure systems in hyperoxia and hypoxia. Am J Physiol Lung Cell Mol Physiol. (2001) 281:L1021–7. 10.1152/ajplung.2001.281.4.L1021 PubMed DOI

Stenmark KR, Meyrick B, Galie N, Mooi WJ, McMurtry IF. Animal models of pulmonary arterial hypertension: the hope for etiological discovery and pharmacological cure. Am J Physiol Cell Mol Physiol. (2009) 297:L1013–32. 10.1152/ajplung.00217.2009 PubMed DOI

Labossiere JR, Pelletier J, Thiesen A, Schulz R, Bigam DL, Cheung P. Doxycycline attenuates renal injury in a swine model of neonatal hypoxia-reoxygenation. Shock. (2015) 43:99–105. 10.1097/SHK.0000000000000257 PubMed DOI

Thompson LP, Pence L, Pinkas G, Song H, Telugu BP. Placental hypoxia during early pregnancy causes maternal hypertension and placental insufficiency in the hypoxic guinea pig model. Biol Reprod. (2016) 95:128. 10.1095/biolreprod.116.142273 PubMed DOI PMC

Thelin EP. Experimental models combining traumatic brain injury and hypoxia. Methods Mol Biol. (2016) 1462:459–79. 10.1007/978-1-4939-3816-2_26 PubMed DOI

Cao Z, Jensen LD, Rouhi P, Hosaka K, Länne T, Steffensen JF, et al. . Hypoxia-induced retinopathy model in adult zebrafish. Nat Protoc. (2010) 5:1903–10. 10.1038/nprot.2010.149 PubMed DOI

Bourdillon N, Saugy J, Schmitt L, Rupp T, Yazdani S, Vesin J-M, et al. . Acute and chronic changes in baroreflex sensitivity in hypobaric vs. normobaric hypoxia. Eur J Appl Physiol. (2017) 117:2401–7. 10.1007/s00421-017-3726-6 PubMed DOI

Louis M, Punjabi NM. Effects of acute intermittent hypoxia on glucose metabolism in awake healthy volunteers. J Appl Physiol. (2009) 106:1538–44. 10.1152/japplphysiol.91523.2008 PubMed DOI PMC

Weiss JW, Pépin JL, Gilmartin GS, Thomas R, Nespoulet H, Launois SH, et al. . A new model of chronic intermittent hypoxia in humans: effect on ventilation, sleep, and blood pressure. J Appl Physiol. (2009) 107:17–24. 10.1152/japplphysiol.91165.2008 PubMed DOI PMC

Self DA, Mandella JG, Prinzo OV, Forster EM, Shaffstall RM. Physiological equivalence of normobaric and hypobaric exposures of humans to 25,000 feet (7620 m). Aviat Space Environ Med. (2011) 82:97–103. 10.3357/ASEM.2908.2011 PubMed DOI

Woods DR, O'Hara JP, Boos CJ, Hodkinson PD, Tsakirides C, Hill NE, et al. . Markers of physiological stress during exercise under conditions of normoxia, normobaric hypoxia, hypobaric hypoxia, and genuine high altitude. Eur J Appl Physiol. (2017) 117:893–900. 10.1007/s00421-017-3573-5 PubMed DOI PMC

Ko HC, Gelb BD. Concise review: drug discovery in the age of the induced pluripotent stem cell. Stem Cells Transl Med. (2014) 3:500–509. 10.5966/sctm.2013-0162 PubMed DOI PMC

Sterneckert JL, Reinhardt P, Schöler HR. Investigating human disease using stem cell models. Nat Rev Genet. (2014) 15:625–39. 10.1038/nrg3764 PubMed DOI

Shi Y, Inoue H, Wu JC, Yamanaka S. Induced pluripotent stem cell technology: a decade of progress. Nat Rev Drug Discov. (2017) 16:115–30. 10.1038/nrd.2016.245 PubMed DOI PMC

Ilic D, Ogilvie C. Concise review: human embryonic stem cells-what have we done? What are we ng? Where are we going? Stem Cells. (2017) 35:17–25. 10.1002/stem.2450 PubMed DOI

Dutta D, Heo I, Clevers H. Disease modeling in stem cell-derived 3D organoid systems. Trends Mol Med. (2017) 23:393–410. 10.1016/j.molmed.2017.02.007 PubMed DOI

Zhang YS, Aleman J, Shin SR, Kilic T, Kim D, Mousavi Shaegh SA, et al. . Multisensor-integrated organs-on-chips platform for automated and continual in situ monitoring of organoid behaviors. Proc Natl Acad Sci USA. (2017) 114:E2293–302. 10.1073/pnas.1612906114 PubMed DOI PMC

Place TL, Domann FE, Case AJ. Limitations of oxygen delivery to cells in culture: an underappreciated problem in basic and translational research. Free Radic Biol Med. (2017) 113:311–22. 10.1016/j.freeradbiomed.2017.10.003 PubMed DOI PMC

Cree IA. Cancer cell culture. In: Cree IA. editor. Totowa, NJ: Humana Press; (2011). 10.1007/978-1-61779-080-5 DOI

Woo W, Yeo SI. Dalton's law vs, amagat's law for the mixture of real gases. SNU J Educ Res. (1995) 5:127–34.

Story DA. Alveolar oxygen partial pressure, alveolar carbon dioxide partial pressure, and the alveolar gas equation. Anesthesiology. (1996) 84:1011. 10.1097/00000542-199604000-00036 PubMed DOI

Krogh A. The rate of diffusion of gases through animal tissues, with some remarks on the coefficient of invasion. J Physiol. (1919) 52:391–408. 10.1113/jphysiol.1919.sp001838 PubMed DOI PMC

Stevens KM. Oxygen requirements for liver cells in vitro. Nature. (1965) 206:199. 10.1038/206199a0 PubMed DOI

Weiszenstein M, Pavlikova N, Elkalaf M, Halada P, Seda O, Trnka J, et al. . The effect of pericellular oxygen levels on proteomic profile and lipogenesis in 3T3-L1 differentiated preadipocytes cultured on gas-permeable cultureware. PLoS ONE. (2016) 11:e0152382. 10.1371/journal.pone.0152382 PubMed DOI PMC

Musutova M, Elkalaf M, Klubickova N, Koc M, Povysil S, Rambousek J, et al. . The effect of hypoxia and metformin on fatty acid uptake, storage, and oxidation in L6 differentiated myotubes. Front Endocrinol. (2018) 9:1–11. 10.3389/fendo.2018.00616 PubMed DOI PMC

Oze H, Hirao M, Ebina K, Shi K, Kawato Y, Kaneshiro S, et al. . Impact of medium volume and oxygen concentration in the incubator on pericellular oxygen concentration and differentiation of murine chondrogenic cell culture. Vitr Cell Dev Biol Anim. (2012) 48:123–30. 10.1007/s11626-011-9479-3 PubMed DOI

Polak J, Studer-Rabler K, McHugh H, Hussain MA, Shimoda LA. System for exposing cultured cells to intermittent hypoxia utilizing gas permeable cultureware. Gen Physiol Biophys. (2015) 34:235–47. 10.4149/gpb_2014043 PubMed DOI PMC

Maddalena LA, Selim SM, Fonseca J, Messner H, McGowan S, Stuart JA. Hydrogen peroxide production is affected by oxygen levels in mammalian cell culture. Biochem Biophys Res Commun. (2017) 493:246–51. 10.1016/j.bbrc.2017.09.037 PubMed DOI

Kieninger J, Aravindalochanan K, Sandvik JA, Pettersen EO, Urban GA. Pericellular oxygen monitoring with integrated sensor chips for reproducible cell culture experiments. Cell Prolif . (2014) 47:180–8. 10.1111/j.1365-2184.2013.12089.x PubMed DOI PMC

Chen B, Longtine MS, Nelson DM. Pericellular oxygen concentration of cultured primary human trophoblasts. Placenta. (2013) 34:106–9. 10.1016/j.placenta.2012.11.011 PubMed DOI PMC

Christmas KM, Bassingthwaighte JB. Equations for O2 and CO2 solubilities in saline and plasma: combining temperature and density dependences. J Appl Physiol. (2017) 122:1313–20. 10.1152/japplphysiol.01124.2016 PubMed DOI PMC

Popel AS. Theory of oxygen transport to tissue. Crit Rev Biomed Eng. (1989) 17:257–321. PubMed PMC

Buck LD, Inman SW, Rusyn I, Griffith LG. Co-regulation of primary mouse hepatocyte viability and function by oxygen and matrix. Biotechnol Bioeng. (2014) 111:1018–27. 10.1002/bit.25152 PubMed DOI PMC

Clark LC, Kaplan S, Matthews EC, Edwards FK, Helmsworth JA. Monitor and control of blood oxygen tension and pH during total body perfusion. J Thorac Surg. (1958) 36:488–96. PubMed

Detz RJ, Abiri Z, Kluwer AM, Reek JNH. A fluorescence-based screening protocol for the identification of water oxidation catalysts. ChemSusChem. (2015) 8:3057–61. 10.1002/cssc.201500558 PubMed DOI

Hong S, Tilan JU, Galli S, Acree R, Connors K, Mahajan A, et al. In vivo model for testing effect of hypoxia on tumor metastasis. J Vis Exp. (2016) 118:1–12. 10.3791/54532 PubMed DOI PMC

Kizaka-Kondoh S, Konse-Nagasawa H. Significance of nitroimidazole compounds and hypoxia-inducible factor-1 for imaging tumor hypoxia. Cancer Sci. (2009) 100:1366–73. 10.1111/j.1349-7006.2009.01195.x PubMed DOI PMC

Shahrzad S, Bertrand K, Minhas K, Coomber B. Induction of DNA hypomethylation by tumor hypoxia. Epigenetics. (2007) 2:119–25. 10.4161/epi.2.2.4613 PubMed DOI

Zhdanov AV, Ogurtsov VI, Taylor CT, Papkovsky DB. Monitoring of cell oxygenation and responses to metabolic stimulation by intracellular oxygen sensing technique. Integr Biol. (2010) 2:443–51. 10.1039/c0ib00021c PubMed DOI

Oppegard SC, Blake AJ, Williams JC, Eddington DT. Precise control over the oxygen conditions within the Boyden chamber using a microfabricated insert. Lab Chip. (2010) 10:2366. 10.1039/c004856a PubMed DOI

Taylor CT, Kent BD, Crinion SJ, McNicholas WT, Ryan S. Human adipocytes are highly sensitive to intermittent hypoxia induced NF-kappaB activity and subsequent inflammatory gene expression. Biochem Biophys Res Commun. (2014) 447:660–5. 10.1016/j.bbrc.2014.04.062 PubMed DOI

Toffoli S, Roegiers A, Feron O, Van Steenbrugge M, Ninane N, Raes M, et al. . Intermittent hypoxia is an angiogenic inducer for endothelial cells: role of HIF-1. Angiogenesis. (2009) 12:47–67. 10.1007/s10456-009-9131-y PubMed DOI

Toffoli S, Delaive E, Dieu M, Feron O, Raes M, Michiels C. NDRG1 and CRK-I/II are regulators of endothelial cell migration under intermittent hypoxia. Angiogenesis. (2009) 12:339–54. 10.1007/s10456-009-9156-2 PubMed DOI

Koch CJ. A thin-film culturing technique allowing rapid gas-liquid equilibration (6 sec) with no toxicity to mammalian cells. Radiat Res. (1984) 97:434–42. 10.2307/3576294 PubMed DOI

Campillo N, Jorba I, Schaedel L, Casals B, Gozal D, Farré R, et al. . A novel chip for cyclic stretch and intermittent hypoxia cell exposures mimicking obstructive sleep apnea. Front Physiol. (2016) 7:1–12. 10.3389/fphys.2016.00319 PubMed DOI PMC

Minoves M, Morand J, Perriot F, Chatard M, Gonthier B, Lemarié E, et al. An innovative intermittent hypoxia model for cell cultures allowing fast P <scp>o</scp> 2 oscillations with minimal gas consumption. Am J Physiol Physiol. (2017) 313:C460–8. 10.1152/ajpcell.00098.2017 PubMed DOI

Murphy AM, Thomas A, Crinion SJ, Kent BD, Tambuwala MM, Fabre A, et al. . Intermittent hypoxia in obstructive sleep apnoea mediates insulin resistance through adipose tissue inflammation. Eur Respir J. (2017) 49:1601731. 10.1183/13993003.01731-2016 PubMed DOI

Otto CM, Baumgardner JE. Effect of culture PO2 on macrophage (RAW 264.7) nitric oxide production. Am J Physiol Cell Physiol. (2001) 280:C280–7. 10.1152/ajpcell.2001.280.2.C280 PubMed DOI

Redline S, Gottlieb DJ, Ho V, Crainiceanu CM, Punjabi NM. Calibration model for apnea-hypopnea indices: impact of alternative criteria for hypopneas. Sleep. (2015) 38:1887–92. 10.5665/sleep.5234 PubMed DOI PMC

Oppegard SC, Eddington DT. Device for the control of oxygen concentration in multiwell cell culture plates. Conf Proc. Annu Int Conf IEEE Eng Med Biol Soc IEEE Eng Med Biol Soc Annu Conf . (2009) 2009:2097–100. 10.1109/IEMBS.2009.5332491 PubMed DOI

Polotsky VY, Savransky V, Bevans-Fonti S, Reinke C, Li J, Grigoryev DN, Shimoda LA. Intermittent and sustained hypoxia induce a similar gene expression profile in human aortic endothelial cells. Physiol Genomics. (2010) 41:306–314. 10.1152/physiolgenomics.00091.2009 PubMed DOI PMC

Baumgardner JE, Otto CM. In vitro intermittent hypoxia: challenges for creating hypoxia in cell culture. Respir Physiol Neurobiol. (2003) 136:131–9. 10.1016/S1569-9048(03)00077-6 PubMed DOI

Tsapikouni T, Garreta E, Melo E, Navajas D, Farré R. A bioreactor for subjecting cultured cells to fast-rate intermittent hypoxia. Respir Physiol Neurobiol. (2012) 182:47–52. 10.1016/j.resp.2012.01.001 PubMed DOI

Polinkovsky M, Gutierrez E, Levchenko A, Groisman A. Fine temporal control of the medium gas content and acidity and on-chip generation of series of oxygen concentrations for cell cultures. Lab Chip. (2009) 9:1073. 10.1039/b816191g PubMed DOI

Lam RHW, Kim M, Thorsen T. Culturing aerobic and anaerobic bacteria and mammalian cells with a microfluidic differential oxygenator. Anal Chem. (2009) 81:5918–24. 10.1021/ac9006864 PubMed DOI PMC

Lo JF, Wang Y, Blake A, Yu G, Harvat TA, Jeon H, et al. . Islet preconditioning via multimodal microfluidic modulation of intermittent hypoxia. Anal Chem. (2012) 84:1987–93. 10.1021/ac2030909 PubMed DOI PMC

Ryan S, Taylor CT, McNicholas WT. Selective activation of inflammatory pathways by intermittent hypoxia in obstructive sleep apnea syndrome. Circulation. (2005) 112:2660–7. 10.1161/CIRCULATIONAHA.105.556746 PubMed DOI

Wree A, Mayer A, Westphal S, Beilfuss A, Canbay A, Schick RR, et al. . Adipokine expression in brown and white adipocytes in response to hypoxia. J Endocrinol Invest. (2012) 35:522–7. 10.3275/7964 PubMed DOI

Haslip M, Dostanic I, Huang Y, Zhang Y, Russell KS, Jurczak MJ, et al. . Endothelial uncoupling protein 2 regulates mitophagy and pulmonary hypertension during intermittent hypoxia. Arterioscler Thromb Vasc Biol. (2015) 35:1166–78. 10.1161/ATVBAHA.114.304865 PubMed DOI PMC

Mees G, Dierckx R, Vangestel C, Laukens D, Van Damme N, Van De Wiele C. Pharmacologic activation of tumor hypoxia: a means to increase tumor 2-deoxy-2-[18F]fluoro-D-glucose uptake? Mol Imaging. (2013) 12:49–58. 10.2310/7290.2012.00020 PubMed DOI

Liu S, Yin Y, Yu R, Li Y, Zhang W. R-spondin3-LGR4 signaling protects hepatocytes against DMOG-induced hypoxia/reoxygenation injury through activating β-catenin. Biochem Biophys Res Commun. (2018) 499:59–65. 10.1016/j.bbrc.2018.03.126 PubMed DOI PMC

Sethi K, Rao K, Bolton D, Patel O, Ischia J. Targeting HIF-1 α to prevent renal ischemia-reperfusion injury: does it work? Int J Cell Biol. (2018) 2018:1–7. 10.1155/2018/9852791 PubMed DOI PMC

Davis CK, Jain SA, Bae O-N, Majid A, Rajanikant GK. Hypoxia mimetic agents for ischemic stroke. Front Cell Dev Biol. (2019) 6:1–12. 10.3389/fcell.2018.00175 PubMed DOI PMC

Chatard M, Puech C, Perek N, Roche F. Hydralazine is a suitable mimetic agent of hypoxia to study the impact of hypoxic stress on in vitro blood-brain barrier model. Cell Physiol Biochem. (2017) 42:1592–602. 10.1159/000479399 PubMed DOI

Zhdanov AV, Dmitriev RI, Papkovsky DB. Bafilomycin A1 activates HIF-dependent signalling in human colon cancer cells via mitochondrial uncoupling. Biosci Rep. (2012) 32:587–95. 10.1042/BSR20120085 PubMed DOI PMC

Wenger RH, Kurtcuoglu V, Scholz CC, Marti HH, Hoogewijs D. Frequently asked questions in hypoxia research. Hypoxia. (2015) 3:35–43. 10.2147/HP.S92198 PubMed DOI PMC

Wagner BA, Venkataraman S, Buettner GR. The rate of oxygen utilization by cells. Free Radic Biol Med. (2011) 51:700–12. 10.1016/j.freeradbiomed.2011.05.024 PubMed DOI PMC

Pasarica M, Sereda OR, Redman LM, Albarado DC, Hymel DT, Roan LE, et al. . Reduced adipose tissue oxygenation in human obesity: evidence for rarefaction, macrophage chemotaxis, and inflammation without an angiogenic response. Diabetes. (2009) 58:718–25. 10.2337/db08-1098 PubMed DOI PMC

Ye J. Emerging role of adipose tissue hypoxia in obesity and insulin resistance. Int J Obes. (2009) 33:54–66. 10.1038/ijo.2008.229 PubMed DOI PMC

Choi JR, Pingguan-Murphy B, Wan Abas WAB, Yong KW, Poon CT, Noor Azmi MA, et al. . In situ normoxia enhances survival and proliferation rate of human adipose tissue-derived stromal cells without increasing the risk of tumourigenesis. PLoS ONE. (2015) 10:e0115034. 10.1371/journal.pone.0115034 PubMed DOI PMC

Maltepe E, Saugstad OD. Oxygen in health and disease: regulation of oxygen homeostasis–clinical implications. Pediatr Res. (2009) 65:261–8. 10.1203/PDR.0b013e31818fc83f PubMed DOI

Morin SJ. Oxygen tension in embryo culture: does a shift to 2% O2 in extended culture represent the most physiologic system? J Assist Reprod Genet. (2017) 34:309–14. 10.1007/s10815-017-0880-z PubMed DOI PMC

Ezashi T, Das P, Roberts RM. Low O2 tensions and the prevention of differentiation of HES cells. Nat Methods. (2005) 2:325 10.1073/pnas.0501283102 PubMed DOI PMC

Forsyth NR, Kay A, Hampson K, Downing A, Talbot R, McWhir J. Transcriptome alterations due to physiological normoxic (2% O2) culture of human embryonic stem cells. Regen Med. (2008) 3:817–33. 10.2217/17460751.3.6.817 PubMed DOI

Chen H-F, Kuo H-C, Lin S-P, Chien C-L, Chiang M-S, Ho H-N. Hypoxic culture maintains self-renewal and enhances embryoid body formation of human embryonic stem cells. Tissue Eng Part A. (2010) 16:2901–13. 10.1089/ten.tea.2009.0722 PubMed DOI

Lim HJ, Han J, Woo DH, Kim SE, Kim SK, Kang HG, et al. . Biochemical and morphological effects of hypoxic environment on human embryonic stem cells in long-term culture and differentiating embryoid bodies. Mol Cells. (2011) 31:123–32. 10.1007/s10059-011-0016-8 PubMed DOI PMC

Fynes K, Tostoes R, Ruban L, Weil B, Mason C, Veraitch FS. The differential effects of 2% oxygen preconditioning on the subsequent differentiation of mouse and human pluripotent stem cells. Stem Cells Dev. (2014) 23:1910–22. 10.1089/scd.2013.0504 PubMed DOI

Chen HF, Kuo HC, Chen W, Wu FC, Yang YS, Ho HN. A reduced oxygen tension (5%) is not beneficial for maintaining human embryonic stem cells in the undifferentiated state with short splitting intervals. Hum Reprod. (2009) 24:71–80. 10.1093/humrep/den345 PubMed DOI

Mohyeldin A, Garzón-Muvdi T, Quiñones-Hinojosa A. Oxygen in stem cell biology: a critical component of the stem cell niche. Cell Stem Cell. (2010) 7:150–61. 10.1016/j.stem.2010.07.007 PubMed DOI

Chen KG, Mallon BS, McKay RDG, Robey PG. Human pluripotent stem cell culture: considerations for maintenance, expansion, and therapeutics. Cell Stem Cell. (2014) 14:13–26. 10.1016/j.stem.2013.12.005 PubMed DOI PMC

Rumsey WL, Pawlowski M, Lejavardi N, Wilson DF. Oxygen pressure distribution in the heart in vivo and evaluation of the ischemic “border zone.” Am J Physiol. (1994) 266:H1676–80. 10.1152/ajpheart.1994.266.4.H1676 PubMed DOI

Linsenmeier RA, Zhang HF. Retinal oxygen: from animals to humans. Prog Retin Eye Res. (2017) 58:115–51. 10.1016/j.preteyeres.2017.01.003 PubMed DOI PMC

Zamudio S, Borges M, Echalar L, Kovalenko O, Vargas E, Torricos T, et al. . Maternal and fetoplacental hypoxia do not alter circulating angiogenic growth effectors during human pregnancy1. Biol Reprod. (2014) 90:1–9. 10.1095/biolreprod.113.115592 PubMed DOI PMC

Farré R, Navajas D, Planas AM, Almendros I, Bonsignore MR, Torres M, et al. . Tissue oxygenation in brain, muscle, and fat in a rat model of sleep apnea: differential effect of obstructive apneas and intermittent hypoxia. Sleep. (2011) 34:1127–33. 10.5665/SLEEP.1176 PubMed DOI PMC

Thorn CE, Knight B, Pastel E, McCulloch LJ, Patel B, Shore AC, et al. . Adipose tissue is influenced by hypoxia of obstructive sleep apnea syndrome independent of obesity. Diabetes Metab. (2017) 43:240–7. 10.1016/j.diabet.2016.12.002 PubMed DOI

Abe H, Semba H, Takeda N. The roles of hypoxia signaling in the pathogenesis of cardiovascular diseases. J Atheroscler Thromb. (2017) 24:884–94. 10.5551/jat.RV17009 PubMed DOI PMC

Fan J, Fan X, Li Y, Ding L, Zheng Q, Guo J, et al. . Chronic normobaric hypoxia induces pulmonary hypertension in rats: role of NF-κB. High Alt Med Biol. (2016) 17:43–9. 10.1089/ham.2015.0086 PubMed DOI

Liu M, Ning X, Li R, Yang Z, Yang X, Sun S, et al. . Signalling pathways involved in hypoxia-induced renal fibrosis. J Cell Mol Med. (2017) 21:1248–59. 10.1111/jcmm.13060 PubMed DOI PMC

Jaitovich A, Jourd'heuil D. In: ed Wang Y-X. Pulmonary Vasculature Redox Signaling in Health and Disease. Cham: Springer International Publishing; (2017).

Shimoda LA, Polak J. Hypoxia. 4. Hypoxia and ion channel function. Am J Physiol Physiol. (2011) 300:C951–67. 10.1152/ajpcell.00512.2010 PubMed DOI PMC

Wang GL, Jiang BH, Rue EA, Semenza GL. Hypoxia-inducible factor 1 is a basic-helix-loop-helix-PAS heterodimer regulated by cellular O2 tension. Proc Natl Acad Sci USA. (1995) 92:5510–4. 10.1073/pnas.92.12.5510 PubMed DOI PMC

Michiels C, Minet E, Mottet D, Raes M. Regulation of gene expression by oxygen: NF-kappaB and HIF-1, two extremes. Free Radic Biol Med. (2002) 33:1231–42. 10.1016/S0891-5849(02)01045-6 PubMed DOI

Zepeda AB, Pessoa A, Castillo RL, Figueroa CA, Pulgar VM, Farías JG. Cellular and molecular mechanisms in the hypoxic tissue: role of HIF-1 and ROS. Cell Biochem Funct. (2013) 31:451–9. 10.1002/cbf.2985 PubMed DOI

Zhang L, Hu Y, Xi N, Song J, Huang W, Song S, et al. . Partial oxygen pressure affects the expression of prognostic biomarkers HIF-1 alpha, Ki67, and CK20 in the microenvironment of colorectal cancer tissue. Oxid Med Cell Longev. (2016) 2016:1–12. 10.1155/2016/1204715 PubMed DOI PMC

Jiang BH, Semenza GL, Bauer C, Marti HH. Hypoxia-inducible factor 1 levels vary exponentially over a physiologically relevant range of O2 tension. Am J Physiol. (1996) 271:C1172-80. 10.1152/ajpcell.1996.271.4.C1172 PubMed DOI

Edin NJ, Olsen DR, Sandvik JA, Malinen E, Pettersen EO. Low dose hyper-radiosensitivity is eliminated during exposure to cycling hypoxia but returns after reoxygenation. Int J Radiat Biol. (2012) 88:311–9. 10.3109/09553002.2012.646046 PubMed DOI

Lee B, Chiu N, Hsia C, Shen L. Accumulation of Tc-99m HL91 in tumor hypoxia: in vitro cell culture and in vivo tumor model. Kaohsiung J Med Sci. (2008) 24:461–72. 10.1016/S1607-551X(09)70003-8 PubMed DOI PMC

Wang L, Liu W, Wang Y, Wang J, Tu Q, Liu R, et al. . Construction of oxygen and chemical concentration gradients in a single microfluidic device for studying tumor cell-drug interactions in a dynamic hypoxia microenvironment. Lab Chip. (2013) 13:695–705. 10.1039/C2LC40661F PubMed DOI

Byrne MB, Leslie MT, Gaskins HR, Kenis PJA. Methods to study the tumor microenvironment under controlled oxygen conditions. Trends Biotechnol. (2014) 32:556–63. 10.1016/j.tibtech.2014.09.006 PubMed DOI PMC

Xi C, Liang X, Chen C, Babazada H, Li T, Liu R. Hypoxia Induces Internalization of κ-Opioid Receptor. Anesthesiology. (2017) 126:842–54. 10.1097/ALN.0000000000001571 PubMed DOI PMC

Panel M, Ghaleh B, Morin D. Ca2+ ionophores are not suitable for inducing mPTP opening in murine isolated adult cardiac myocytes. Sci Rep. (2017) 7:4283 10.1038/s41598-017-04618-4 PubMed DOI PMC

Martewicz S, Michielin F, Serena E, Zambon A, Mongillo M, Elvassore N. Reversible alteration of calcium dynamics in cardiomyocytes during acute hypoxia transient in a microfluidic platform. Integr Biol. (2012) 4:153–64. 10.1039/C1IB00087J PubMed DOI

Wang B, Wood IS, Trayhurn P. Dysregulation of the expression and secretion of inflammation-related adipokines by hypoxia in human adipocytes. Pflügers Arch Eur J Physiol. (2007) 455:479–92. 10.1007/s00424-007-0301-8 PubMed DOI PMC

Floyd ZE, Kilroy G, Wu X, Gimble JM. Effects of prolyl hydroxylase inhibitors on adipogenesis and hypoxia inducible factor 1 alpha levels under normoxic conditions. J Cell Biochem. (2007) 101:1545–57. 10.1002/jcb.21266 PubMed DOI

Chuang L, Chen N, Lin S-W, Chang Y, Liao H, Lin Y-S, et al. . Increased C-C chemokine receptor 2 gene expression in monocytes of severe obstructive sleep apnea patients and under intermittent hypoxia. PLoS ONE. (2014) 9:e113304. 10.1371/journal.pone.0113304 PubMed DOI PMC

Chuang L, Chen N, Lin Y, Ko W, Pang JS. Increased MCP-1 gene expression in monocytes of severe OSA patients and under intermittent hypoxia. Sleep Breath. (2016) 20:425–33. 10.1007/s11325-015-1252-5 PubMed DOI

Philippe C, Boussadia Y, Prulière-Escabasse V, Papon JF, Clérici C, Isabey D, et al. . Airway cell involvement in intermittent hypoxia-induced airway inflammation. Sleep Breath. (2015) 19:297–306. 10.1007/s11325-014-1019-4 PubMed DOI

Dyugovskaya L, Polyakov A, Lavie P, Lavie L. Delayed neutrophil apoptosis in patients with sleep apnea. Am J Respir Crit Care Med. (2008) 177:544–54. 10.1164/rccm.200705-675OC PubMed DOI

Yuan G, Nanduri J, Bhasker CR, Semenza GL, Prabhakar NR. Ca 2+ /calmodulin kinase-dependent activation of hypoxia inducible factor 1 transcriptional activity in cells subjected to intermittent hypoxia. J Biol Chem. (2005) 280:4321–28. 10.1074/jbc.M407706200 PubMed DOI

Kaczmarek E, Bakker JP, Clarke DN, Csizmadia E, Kocher O, Veves A, et al. . Molecular biomarkers of vascular dysfunction in obstructive sleep apnea. PLoS ONE. (2013) 8:e70559. 10.1371/journal.pone.0070559 PubMed DOI PMC

Li C, Ni C, Yang M, Tang Y, Li Z, Zhu Y, et al. . Honokiol protects pancreatic β cell against high glucose and intermittent hypoxia-induced injury by activating Nrf2/ARE pathway in vitro and in vivo. Biomed Pharmacother. (2018) 97:1229–37. 10.1016/j.biopha.2017.11.063 PubMed DOI

Wu J, Stefaniak J, Hafner C, Schramel JP, Kaun C, Wojta J, et al. . Intermittent hypoxia causes inflammation and injury to human adult cardiac myocytes. Anesth Analg. (2016) 122:373–80. 10.1213/ANE.0000000000001048 PubMed DOI

Liu K, Chen G, Lin P-L, Huang J, Lin X, Qi J, et al. . Detection and analysis of apoptosis- and autophagy-related miRNAs of mouse vascular endothelial cells in chronic intermittent hypoxia model. Life Sci. (2018) 193:194–9. 10.1016/j.lfs.2017.11.001 PubMed DOI

Zhou Y, Richards AM, Wang P. Characterization and standardization of cultured cardiac fibroblasts for ex vivo models of heart fibrosis and heart ischemia. Tissue Eng Part C Methods. (2017) 23:422–33. 10.1089/ten.tec.2017.0169 PubMed DOI

Ren J, Liu W, Li G, Jin M, You Z, Liu H, et al. . Atorvastatin attenuates myocardial hypertrophy induced by chronic intermittent hypoxia in vitro partly through miR-31/PKCε pathway. Curr Med Sci. (2018) 38:405–12. 10.1007/s11596-018-1893-2 PubMed DOI

Gagner J, Lechpammer M, Zagzag D. Induction and assessment of hypoxia in glioblastoma cells in vitro. In: Placantonakis D. editor. Methods in Molecular Biology. New York, NY: Springer Science+Business Media; (2018). p. 111–23. PubMed

Zagzag D, Esencay M, Mendez O, Yee H, Smirnova I, Huang Y, et al. . Hypoxia- and vascular endothelial growth factor-induced stromal cell-derived factor-1α/CXCR4 expression in glioblastomas. Am J Pathol. (2008) 173:545–60. 10.2353/ajpath.2008.071197 PubMed DOI PMC

Zagzag D, Lukyanov Y, Lan L, Ali MA, Esencay M, Mendez O, et al. . Hypoxia-inducible factor 1 and VEGF upregulate CXCR4 in glioblastoma: implications for angiogenesis and glioma cell invasion. Lab Investig. (2006) 86:1221–32. 10.1038/labinvest.3700482 PubMed DOI

Chanana V, Tumturk A, Kintner D, Udho E, Ferrazzano P, Cengiz P. Sex differences in mouse hippocampal astrocytes after in-vitro ischemia. J Vis Exp. (2016) 116:1-9. 10.3791/53695 PubMed DOI PMC

Wang X, Wang W, Wang J, Yang C, Liang C. Effect of apigenin on apoptosis induced by renal ischemia/reperfusion injury in vivo and in vitro. Ren Fail. (2018) 40:498–505. 10.1080/0886022X.2018.1497517 PubMed DOI PMC

Radovits T, Zotkina J, Lin L, Karck M, Szabó G. Endothelial dysfunction after hypoxia–reoxygenation: do in vitro models work? Vascul Pharmacol. (2009) 51:37–43. 10.1016/j.vph.2009.01.009 PubMed DOI

Wu D, Yotnda P. Induction and testing of hypoxia in cell culture. J Vis Exp. (2011) 54:2–5. 10.3791/2899 PubMed DOI PMC

Maugeri G, D'Amico AG, Rasà DM, La Cognata V, Saccone S, Federico C, et al. . Caffeine prevents blood retinal barrier damage in a model, in vitro, of diabetic macular edema. J Cell Biochem. (2017) 118:2371–9. 10.1002/jcb.25899 PubMed DOI

Zagzag D, Zhong H, Scalzitti JM, Laughner E, Simons JW, Semenza GL. Expression of hypoxia-inducible factor 1alpha in brain tumors: association with angiogenesis, invasion, and progression. Cancer. (2000) 88:2606–18. 10.1002/1097-0142(20000601)88:11<2606::AID-CNCR25>3.0.CO;2-W PubMed DOI

Ord JJ, Streeter EH, Roberts ISD, Cranston D, Harris AL. Comparison of hypoxia transcriptome in vitro with in vivo gene expression in human bladder cancer. Br J Cancer. (2005) 93:346–54. 10.1038/sj.bjc.6602666 PubMed DOI PMC

Duval K, Grover H, Han L, Mou Y, Pegoraro AF, Fredberg J, et al. . Modeling physiological events in 2D vs. 3D cell culture. Physiology. (2017) 32:266–77. 10.1152/physiol.00036.2016 PubMed DOI PMC

Tanner K, Mori H, Mroue R, Bruni-Cardoso A, Bissell MJ. Coherent angular motion in the establishment of multicellular architecture of glandular tissues. Proc Natl Acad Sci USA. (2012) 109:1973–8. 10.1073/pnas.1119578109 PubMed DOI PMC

Wartenberg M, Ling FC, Müschen M, Klein F, Acker H, Gassmann M, et al. . Regulation of the multidrug resistance transporter P-glycoprotein in multicellular tumor spheroids by hypoxia-inducible factor (HIF-1) and reactive oxygen species. FASEB J. (2003) 17:503–5. 10.1096/fj.02-0358fje PubMed DOI

Magdeldin T, López-Dávila V, Pape J, Cameron GWW, Emberton M, Loizidou M, et al. . Engineering a vascularised 3D in vitro model of cancer progression. Sci Rep. (2017) 7:44045. 10.1038/srep44045 PubMed DOI PMC

Benton G, DeGray G, Kleinman HK, George J, Arnaoutova I. In vitro microtumors provide a physiologically predictive tool for breast cancer therapeutic screening. PLoS ONE. (2015) 10:e0123312. 10.1371/journal.pone.0123312 PubMed DOI PMC

Leek R, Grimes DR, Harris AL, Mcintyre A. In: Koumenis C, Coussens LM, Giaccia A, Hammond E. editors. Tumor Microenvironment. Cham: Springer International Publishing; (2016).

Cubillos-Zapata C, Hernández-Jiménez E, Avendaño-Ortiz J, Toledano V, Varela-Serrano A, Fernández-Navarro I, et al. . Obstructive sleep apnea monocytes exhibit high levels of vascular endothelial growth factor secretion, augmenting tumor progression. Med Inflamm. (2018) 2018:1–9. 10.1155/2018/7373921 PubMed DOI PMC

Hunyor I, Cook KM. Models of intermittent hypoxia and obstructive sleep apnea: molecular pathways and their contribution to cancer. Am J Physiol Regul Integr Comp Physiol. (2018) 315:R669–87. 10.1152/ajpregu.00036.2018 PubMed DOI

Bauer M, Kang L, Qiu Y, Wu J, Peng M, Chen HH, et al. . Adult cardiac progenitor cell aggregates exhibit survival benefit both in vitro and in vivo. PLoS ONE. (2012) 7:e50491. 10.1371/journal.pone.0050491 PubMed DOI PMC

Sepuri NBV, Angireddy R, Srinivasan S, Guha M, Spear J, Lu B, et al. . Mitochondrial LON protease-dependent degradation of cytochrome c oxidase subunits under hypoxia and myocardial ischemia. Biochim Biophys Acta Bioenerg. (2017) 1858:519–28. 10.1016/j.bbabio.2017.04.003 PubMed DOI PMC

Acun A, Zorlutuna P. Engineered myocardium model to study the roles of HIF-1α and HIF1A-AS1 in paracrine-only signaling under pathological level oxidative stress. Acta Biomater. (2017) 58:323–36. 10.1016/j.actbio.2017.06.023 PubMed DOI PMC

Chaitanya G, Minagar A, Alexander JS. Neuronal and astrocytic interactions modulate brain endothelial properties during metabolic stresses of in vitro cerebral ischemia. Cell Commun Signal. (2014) 12:7. 10.1186/1478-811X-12-7 PubMed DOI PMC

Gammella E, Leuenberger C, Gassmann M, Ostergaard L. Evidence of synergistic/additive effects of sildenafil and erythropoietin in enhancing survival and migration of hypoxic endothelial cells. Am J Physiol Cell Mol Physiol. (2013) 304:L230–9. 10.1152/ajplung.00112.2012 PubMed DOI

Sucre JMS, Vijayaraj P, Aros CJ, Wilkinson D, Paul M, Dunn B, et al. . Posttranslational modification of β-catenin is associated with pathogenic fibroblastic changes in bronchopulmonary dysplasia. Am J Physiol Cell Mol Physiol. (2017) 312:L186–95. 10.1152/ajplung.00477.2016 PubMed DOI PMC

Ehsan SM, George SC. Vessel network formation in response to intermittent hypoxia is frequency dependent. J Biosci Bioeng. (2015) 120:347–50. 10.1016/j.jbiosc.2015.01.017 PubMed DOI PMC

Lam SF, Shirure VS, Chu YE, Soetikno AG, George SC. Microfluidic device to attain high spatial and temporal control of oxygen. PLoS ONE. (2018) 13:1–16. 10.1371/journal.pone.0209574 PubMed DOI PMC

Alhawarat FM, Hammad HM, Hijjawi MS, Sharab AS, Abuarqoub DA, Al Shhab MA, et al. . The effect of cycling hypoxia on MCF-7 cancer stem cells and the impact of their microenvironment on angiogenesis using human umbilical vein endothelial cells (HUVECs) as a model. PeerJ. (2019) 7:e5990. 10.7717/peerj.5990 PubMed DOI PMC

Beharry KD, Cai CL, Valencia GB, Lazzaro D, Valencia AM, Salomone F, et al. . Human retinal endothelial cells and astrocytes cultured on 3-D scaffolds for ocular drug discovery and development. Prostaglandins Other Lipid Mediat. (2018) 134:93–107. 10.1016/j.prostaglandins.2017.09.005 PubMed DOI PMC

McMurtrey RJ. Analytic models of oxygen and nutrient diffusion, metabolism dynamics, and architecture optimization in three-dimensional tissue constructs with applications and insights in cerebral organoids. Tissue Eng Part C Methods. (2016) 22:221–49. 10.1089/ten.tec.2015.0375 PubMed DOI PMC

Gomes A, Guillaume L, Grimes DR, Fehrenbach J, Lobjois V, Ducommun B. Oxygen partial pressure is a rate-limiting parameter for cell proliferation in 3D spheroids grown in physioxic culture condition. PLoS ONE. (2016) 11:e0161239. 10.1371/journal.pone.0161239 PubMed DOI PMC

Park KM, Gerecht S. Hypoxia-inducible hydrogels. Nat Commun. (2014) 5:4075. 10.1038/ncomms5075 PubMed DOI PMC

Lewis DM, Blatchley MR, Park KM, Gerecht S. O2-controllable hydrogels for studying cellular responses to hypoxic gradients in three dimensions in vitro and in vivo. Nat Protoc. (2017) 12:1620–38. 10.1038/nprot.2017.059 PubMed DOI PMC

Dmitriev RI, Kondrashina AV, Koren K, Klimant I, Zhdanov AV, Pakan JMP, et al. Small molecule phosphorescent probes for O2 imaging in 3D tissue models. Biomater Sci. (2014) 2:853–66. 10.1039/C3BM60272A PubMed DOI

Dmitriev RI, Papkovsky DB. Multi-parametric O2 imaging in three-dimensional neural cell models with the phosphorescent probes. Methods Mol Biol. (2015) 1254:55–71. 10.1007/978-1-4939-2152-2_5 PubMed DOI

Lesher-Pérez SC, Kim G-A, Kuo C, Leung BM, Mong S, Kojima T, et al. . Dispersible oxygen microsensors map oxygen gradients in three-dimensional cell cultures. Biomater Sci. (2017) 5:2106–13. 10.1039/C7BM00119C PubMed DOI PMC

Oppegard SC, Eddington DT. A microfabricated platform for establishing oxygen gradients in 3-D constructs. Biomed Microdevices. (2013) 15:407–14. 10.1007/s10544-013-9737-0 PubMed DOI PMC

Li C, Chaung W, Mozayan C, Chabra R, Wang P, Narayan RK. A new approach for on-demand generation of various oxygen tensions for in vitro hypoxia models. PLoS ONE. (2016) 11:1–13. 10.1371/journal.pone.0155921 PubMed DOI PMC

Langan LM, Dodd NJF, Owen SF, Purcell WM, Jackson SK, Jha AN. Direct measurements of oxygen gradients in spheroid culture system using electron parametric resonance oximetry. PLoS ONE. (2016) 11:e0149492 10.1371/journal.pone.0149492 PubMed DOI PMC

Funamoto K, Zervantonakis IK, Liu Y, Ochs CJ, Kim C, Kamm RD. A novel microfluidic platform for high-resolution imaging of a three-dimensional cell culture under a controlled hypoxic environment. Lab Chip. (2012) 12:4855. 10.1039/c2lc40306d PubMed DOI PMC

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