This research was supported by the National Research Foundation of Korea (NRF) funded by the Ministry of Education (No. 2020R1A6A1A03047902 and NRF-2018H1A2A1062091) and the Korea government (MSIT) (No. NRF-2019R1C1C1009606 and NRF-2019R1A3A3005437).

1. Computer simulation of oxygen gradient formation
<ol>
	<li>Generation of a 3D geometry model for hypoxic cancer-on-a-chip printing
	<ol>
		<li>Run a 3D CAD software.</li>
		<li>Sketch the geometry model of hypoxic cancer-on-a-chip. Click on Sketch and select the desired plane to draw the geometry. Refer to the drawing (Figure 2A) for the detail scale of each part.</li>
		<li>Set the thickness of the geometry by clicking on Feature-Protrusion Bos...

<ol>
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G., Lee, H., Cho, D. -. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=3D+printing+of+organs-on-chips.">3D printing of organs-on-chips.</a> Bioengineering. 4 (1), 10 (2017).</li><li>Yi, H. -. G., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+bioprinted+human-glioblastoma-on-a-chip+for+the+identification+of+patient-specific+responses+to+chemoradiotherapy.">A bioprinted human-glioblastoma-on-a-chip for the identification of patient-specific responses to chemoradiotherapy.</a> Nature Biomedical Engineering. 3 (7), 509-519 (2019).</li><li>Kang, T. -. Y., Hong, J. M., Jung, J. W., Yoo, J. J., Cho, D. -. 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In this study, we describe the fabrication process of a hypoxic cancer-on-a-chip based on 3D cell-printing technology. The formation of the hypoxic gradient in the designed chip was predicted through computer simulations. The environment that can induce a heterogeneous hypoxic gradient was reproduced via a simple strategy combining the 3D-printed gas-permeable barrier and the glass cover. The hypoxia-related pathological features of glioblastoma, including pseudopalisade and a small population of cancer stem cells, were ...

The cancer microenvironment is a critical factor driving cancer progression. Multiple components, including biochemical, biophysical, and cellular cues, determine the pathological features of cancer. Among these, hypoxia is strongly associated with cancer survival, proliferation, and invasion1. Due to the unlimited growth and division of cancer cells, nutrients and oxygen are continuously depleted, and a hypoxic gradient is generated. Under low-oxygen conditions, cells activate hypoxia-inducible transcription factor (HIF)-associated molecular cascade. This process induces a necrotic core, triggers metabolic changes, and initiates blood vessel hyperplasia and metastasis2,3. Subsequently, hypoxia in cancer cells causes the destruction of neighboring normal tissues. Furthermore, hypoxia is strongly associated with the therapeutic resistance of solid tumors in multifactorial manners. Hypoxia may severely impede radiotherapy, as radiosensitivity is limited owing to reactive oxygen species1,4. In addition, it decreases pH levels of cancer microenvironments, which decreases drug accumulation1. Therefore, reproducing pathological features related to hypoxia in vitro is a promising strategy for scientific and pre-clinical findings.
Modeling a specific microenvironment of cancer is essential for understanding cancer development and exploring appropriate treatments. Although animal models have been widely used because of their strong physiological relevance, issues related to species differences and ethical problems exist5. Furthermore, although conventional 2D and 3D models allow for the manipulation and real-time imaging of cancer cells for an in-depth analysis, their architectural and cellular complexity cannot be fully recapitulated. For example, cancer spheroid models have been widely used, as cancer cell aggregation in a spheroid can naturally generate hypoxia in the core. Moreover, large numbers of cellular spheroids of uniform size have been produced using plastic- or silicone-based multi-well systems6,7. However, the lower flexibility with regard to capturing the exact heterogeneous structure of cancerous tissues with conventional platforms has required the establishment of an advanced biofabrication technology to build a highly biomimetic platform to improve cancer research8.
3D microphysiological systems (MPSs) are useful tools to recapitulate the complex geometry and pathological progression of cancer cells9. As cancer cells sense the biochemical gradient of growth factors and chemokines and the mechanical heterogeneity reproduced on the system, important features of cancer development can be investigated in vitro. For instance, cancer viability, metastatic malignancy, and drug resistance depending on the varying oxygen concentrations has been studied using MPSs10,11. Despite recent advancements, generating hypoxic conditions of in vitro models relies on complex fabrication procedures, including connection with physical gas pumps. Therefore, simple, and flexible methods to build cancer-specific microenvironments are needed.
3D cell printing technology has gained considerable attention because of its precise control of the spatial arrangement of biomaterials to recapitulate native biological architectures12. In particular, this technology overcomes the existing limitations of 3D hypoxia models owing to its high controllability and feasibility for building the spatial features of the cancer microenvironment. 3D printing also facilitates computer-aided manufacturing through a layer-by-layer process, thereby providing a rapid, accurate, and reproducible construction of complex geometries to mimic actual tissue architectures. In addition to the advantages of existing manufacturing strategies for 3D MPSs, the pathophysiological features of cancer progression can be reproduced by patterning the biochemical, cellular, and biophysical components13,14.
Herein, we present a 3D cell-printing strategy for a hypoxic cancer-on-a-chip for recapitulating the heterogeneity of a solid cancer (Figure 1)15. The fabrication parameters were determined via a computational simulation of central hypoxia formation in the system. Cancer-stroma concentric rings were printed using collagen bioinks containing glioblastoma cells and endothelial cells to emulate the pathophysiology of glioblastoma, a type of solid cancer. The formation of a radial oxygen gradient aggravated cancer malignancy, indicating strengthened aggressiveness. Furthermore, we indicate future perspectives for the applications of the chip to patient-specific preclinical models. The proposed approach for creating a solid-cancer-mimetic microphysiological system is expected to bridge the gap between in vivo and in vitro models of cancer.

<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td colspan="4">Cells</td>
		</tr>
		<tr>
			<td>Human umbilical vein endothelial cells</td>
			<td>Promocell</td>
			<td>C-12200</td>
			<td></td>
		</tr>
		<tr>
			<td>U-87 MG cells</td>
			<td>ATCC</td>
			<td>ATCC HTB-14</td>
			<td></td>
		</tr>
		<tr>
			<td colspan="4">Disposable</td>
		</tr>
		<tr>
			<td>0.2 &#956;m syringe filter</td>
			<td>Sartorius</td>
			<td>16534-K</td>
			<td></td>
		</tr>
		<tr>
			<td>10 mL disposable syringe</td>
			<td>Jung Rim</td>
			<td>10ml 21G32</td>
			<td></td>
		</tr>
		<tr>
			<td>10 mL glass vial</td>
			<td>Hubena</td>
			<td>A0039</td>
			<td></td>
		</tr>
		<tr>
			<td>10 mL Serological pipette tip</td>
			<td>SPL lifescience</td>
			<td>91010</td>
			<td></td>
		</tr>
		<tr>
			<td>15 mL conical tube</td>
			<td>SPL lifescience</td>
			<td>50015</td>
			<td></td>
		</tr>
		<tr>
			<td>18G plastic needle</td>
			<td>Musashi engineering</td>
			<td>PN-18G-B</td>
			<td></td>
		</tr>
		<tr>
			<td>20G plastic tapered dispense tip</td>
			<td>Musashi engineering</td>
			<td>TPND-20G-U</td>
			<td></td>
		</tr>
		<tr>
			<td>22x50 glass cover</td>
			<td>MARIENFIELD</td>
			<td>0101142</td>
			<td></td>
		</tr>
		<tr>
			<td>25 mL Serological pipette tip</td>
			<td>SPL lifescience</td>
			<td>90125</td>
			<td></td>
		</tr>
		<tr>
			<td>3 mL disposable syringes</td>
			<td>HENKE-JET</td>
			<td>4020-X00V0</td>
			<td></td>
		</tr>
		<tr>
			<td>40 &#181;m cell strainer</td>
			<td>Falcon</td>
			<td>352360</td>
			<td></td>
		</tr>
		<tr>
			<td>5 mL Serological pipette tip</td>
			<td>SPL lifescience</td>
			<td>91005</td>
			<td></td>
		</tr>
		<tr>
			<td>50 mL conical tube</td>
			<td>SPL lifescience</td>
			<td>50050</td>
			<td></td>
		</tr>
		<tr>
			<td>50 mL Serological pipette tip</td>
			<td>SPL lifescience</td>
			<td>90150</td>
			<td></td>
		</tr>
		<tr>
			<td>50N precision nozzle</td>
			<td>Musashi engineering</td>
			<td>HN-0.5ND</td>
			<td></td>
		</tr>
		<tr>
			<td>Aluminum foil</td>
			<td>SINKWANG</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Capillary tips</td>
			<td>Gilson</td>
			<td>CP1000</td>
			<td></td>
		</tr>
		<tr>
			<td>Cell-scrapper</td>
			<td>SPL lifescience</td>
			<td>90030</td>
			<td></td>
		</tr>
		<tr>
			<td>Confocal dish</td>
			<td>SPL lifescience</td>
			<td>200350</td>
			<td></td>
		</tr>
		<tr>
			<td>Parafilm</td>
			<td>Bemis</td>
			<td>PM996</td>
			<td></td>
		</tr>
		<tr>
			<td>Pre-coated histology slide</td>
			<td>MATSUNAMI</td>
			<td>MAS-11</td>
			<td></td>
		</tr>
		<tr>
			<td>Reservoir</td>
			<td>SPL lifescience</td>
			<td>23050</td>
			<td></td>
		</tr>
		<tr>
			<td>T-75 cell culture flask</td>
			<td>SPL lifescience</td>
			<td>70075</td>
			<td></td>
		</tr>
		<tr>
			<td colspan="4">Equipment</td>
		</tr>
		<tr>
			<td>3DX printer</td>
			<td>T&#38;R Biofab</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Autoclave</td>
			<td>JEIOTECH</td>
			<td>AC-12</td>
			<td></td>
		</tr>
		<tr>
			<td>Centrifuger</td>
			<td>Cyrozen</td>
			<td>1580MGR</td>
			<td></td>
		</tr>
		<tr>
			<td>Confocal laser microscopy</td>
			<td>Olympus Life Science</td>
			<td>FV 1000</td>
			<td></td>
		</tr>
		<tr>
			<td>Fluorescence microscope</td>
			<td>FISHER SCEINTIFIC</td>
			<td>O221S366</td>
			<td></td>
		</tr>
		<tr>
			<td>Forcep</td>
			<td>Korea Ace Scientific</td>
			<td>HC.203-30</td>
			<td></td>
		</tr>
		<tr>
			<td>Hand tally counter</td>
			<td>KTRIO</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Hemocytometer</td>
			<td>MARIENFIELD</td>
			<td>0650030</td>
			<td></td>
		</tr>
		<tr>
			<td>Incubator</td>
			<td>Panasonic</td>
			<td>MCO-170AIC</td>
			<td></td>
		</tr>
		<tr>
			<td>Laminar flow cabinet</td>
			<td>DAECHUNG SCIENCE</td>
			<td>CB-BMMS C-001</td>
			<td></td>
		</tr>
		<tr>
			<td>Metal syringe</td>
			<td>IWASHITA engineering</td>
			<td>SUS BARREL 10CC</td>
			<td></td>
		</tr>
		<tr>
			<td>Operating Scissors</td>
			<td>Hirose</td>
			<td>HC.13-122</td>
			<td></td>
		</tr>
		<tr>
			<td>Oven</td>
			<td>JEIOTECH</td>
			<td>OF-12, H070023</td>
			<td></td>
		</tr>
		<tr>
			<td>Positive displacement pipette</td>
			<td>GILSON</td>
			<td>NJ05652</td>
			<td></td>
		</tr>
		<tr>
			<td>Refrigerator</td>
			<td>SAMSUNG</td>
			<td>CRFD-1141</td>
			<td></td>
		</tr>
		<tr>
			<td>Voltex Mixer</td>
			<td>DAIHAN scientific</td>
			<td>VM-10</td>
			<td></td>
		</tr>
		<tr>
			<td>Water bath</td>
			<td>DAIHAN SCIENTIFIC</td>
			<td>WB-11</td>
			<td></td>
		</tr>
		<tr>
			<td>Water purifier</td>
			<td>WASSER LAB</td>
			<td>DI-GR</td>
			<td></td>
		</tr>
		<tr>
			<td colspan="4">Materials</td>
		</tr>
		<tr>
			<td>0.25 % Trypsin-EDTA</td>
			<td>Gibco</td>
			<td>25200-072</td>
			<td></td>
		</tr>
		<tr>
			<td>10x PBS</td>
			<td>Intron</td>
			<td>IBS-BP007a</td>
			<td></td>
		</tr>
		<tr>
			<td>4% Paraformaldehyde</td>
			<td>Biosesang</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>70% Ethanol</td>
			<td>Daejung</td>
			<td>4018-4410</td>
			<td></td>
		</tr>
		<tr>
			<td>Anti-CD31 antibody</td>
			<td>Abcam</td>
			<td>ab28364</td>
			<td></td>
		</tr>
		<tr>
			<td>Anti-HIF-1 alpha antibody</td>
			<td>Abcam</td>
			<td>ab16066</td>
			<td></td>
		</tr>
		<tr>
			<td>Anti-SHMT2/SHMT antibody</td>
			<td>Abcam</td>
			<td>ab88664</td>
			<td></td>
		</tr>
		<tr>
			<td>Anti-SOX2 antibody</td>
			<td>Abcam</td>
			<td>ab75485</td>
			<td></td>
		</tr>
		<tr>
			<td>Bovine Serum Albumin</td>
			<td>Thermo scientific</td>
			<td>J10857-22</td>
			<td></td>
		</tr>
		<tr>
			<td>Collagen from porcine skin</td>
			<td>Dalim tissen</td>
			<td>PC-001-1g</td>
			<td></td>
		</tr>
		<tr>
			<td>DAPI (4&#39;,6-Diamidino-2-Phenylindole, Dihydrochloride)</td>
			<td>Thermofisher</td>
			<td>D1306</td>
			<td></td>
		</tr>
		<tr>
			<td>Endothelial Cell Growth Medium-2</td>
			<td>Promocell</td>
			<td>C22011</td>
			<td></td>
		</tr>
		<tr>
			<td>Fetal bovine serum</td>
			<td>Gibco</td>
			<td>12483-020</td>
			<td></td>
		</tr>
		<tr>
			<td>Goat anti-Mouse IgG (H+L) Cross-Adsorbed Secondary Antibody, Alexa Fluor 488</td>
			<td>Theromofisher</td>
			<td>A-11001</td>
			<td></td>
		</tr>
		<tr>
			<td>Goat anti-Rabbit IgG (H+L) Cross-Adsorbed Secondary Antibody, Alexa Fluor 594</td>
			<td>Theromofisher</td>
			<td>A-11012</td>
			<td></td>
		</tr>
		<tr>
			<td>High-glucose Dulbecco&#8217;s Modified Eagle Medium(DMEM)</td>
			<td>Hyclone</td>
			<td>SH30243-0</td>
			<td></td>
		</tr>
		<tr>
			<td>Hydrochloric acid</td>
			<td>Sigma-Aldrich</td>
			<td>311413-100ML</td>
			<td></td>
		</tr>
		<tr>
			<td>Live/dead assay kit</td>
			<td>Invitrogen</td>
			<td>L3224</td>
			<td></td>
		</tr>
		<tr>
			<td>Mouse IgG1, kappa monoclonal [15-6E10A7] - Isotype Control</td>
			<td>Abcam</td>
			<td>ab170190</td>
			<td></td>
		</tr>
		<tr>
			<td>Penicillin/streptomycin</td>
			<td>Gibco</td>
			<td>15140-122</td>
			<td></td>
		</tr>
		<tr>
			<td>Phenol red solution</td>
			<td>Sigma-Aldrich</td>
			<td>P0290-100ML</td>
			<td></td>
		</tr>
		<tr>
			<td>Poly(ethylene-vinyl acetate)&#160;</td>
			<td>Poly science</td>
			<td>06108-500</td>
			<td></td>
		</tr>
		<tr>
			<td>Polydimethylsiloxane</td>
			<td>Dowhitech</td>
			<td>sylgard 184</td>
			<td></td>
		</tr>
		<tr>
			<td>Rabbit IgG, polyclonal - Isotype Control</td>
			<td>Abcam</td>
			<td>ab37415</td>
			<td></td>
		</tr>
		<tr>
			<td>Sodium hydroxide solution</td>
			<td>Samchun</td>
			<td>S0610</td>
			<td></td>
		</tr>
		<tr>
			<td>Triton X-100</td>
			<td>Biosesang</td>
			<td>TRI020-500-50</td>
			<td></td>
		</tr>
		<tr>
			<td>Trypan Blue</td>
			<td>Sigma-Aldrich</td>
			<td>T8154</td>
			<td></td>
		</tr>
		<tr>
			<td colspan="4">Software</td>
		</tr>
		<tr>
			<td>COMSOL Multiphysics 3.5a</td>
			<td>COMSOL AB</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>IMS beamer</td>
			<td></td>
			<td></td>
			<td>in-house software</td>
		</tr>
		<tr>
			<td>SolidWorks Package</td>
			<td colspan="2">Dassault Systems SolidWorks Corporation</td>
			<td></td>
		</tr>
	</tbody>
</table>

3d cell-printed hypoxic cancer-on-a-chip for recapitulating pathologic progression of solid cancer

Cancer microenvironment has a significant impact on the progression of the disease. In particular, hypoxia is the key driver of cancer survival, invasion, and chemoresistance. Although several in vitro models have been developed to study hypoxia-related cancer pathology, the complex interplay of the cancer microenvironment observed&#160;in vivo has not been reproduced yet owing to the lack of precise spatial control. Instead, 3D biofabrication approaches have been proposed to create microphysiological systems for better emulation of cancer ecology and accurate anticancer treatment evaluation. Herein, we propose a 3D cell-printing approach to fabricate a hypoxic cancer-on-a-chip. The hypoxia-inducing components in the chip were determined based on a computer simulation of the oxygen distribution. Cancer-stroma concentric rings were printed using bioinks containing glioblastoma cells and endothelial cells to recapitulate a type of solid cancer. The resulting chip realized central hypoxia and aggravated malignancy in cancer with the formation of representative pathophysiological markers. Overall, the proposed approach for creating a solid-cancer-mimetic microphysiological system is expected to bridge the gap between in vivo and in vitro models for cancer research.

The hypoxic cancer-on-a-chip was developed using computer-aided 3D cell-printing technology to recapitulate hypoxia and cancer-related pathology (Figure 1). Oxygen transportation and consumption were simulated using the 3D geometry model. The chip was designed in the form of concentric rings to mimic the radial oxygen diffusion and depletion, in cancer tissues (Figure 2A). After defining the control volume of a space where oxygen...

Watch this Scientific Journal Video about 3D Cell-Printed Hypoxic Cancer-on-a-Chip for Recapitulating Pathologic Progression of Solid Cancer at JoVE.com

3D Cell-Printed Hypoxic Cancer-on-a-Chip for Recapitulating Pathologic Progression of Solid Cancer

Hypoxia is a hallmark of tumor microenvironment and plays a crucial role in cancer progression. This article describes the fabrication process of a hypoxic cancer-on-a-chip based on 3D cell-printing technology to recapitulate a hypoxia-related pathology of cancer.

Cancer microenvironment has a significant impact on the progression of the disease. In particular, hypoxia is the key driver of cancer survival, invasion, ...

Hypoxia is a key driver of cancer development that induces genomic instability and tumorigenesis. We demonstrate a method for generating central hypoxia in a solid cancer in vitro based on 3D bioprinting technology. Using this method, a radio hypoxic gradient can be reproduced using a simple strategy that combines a 3D printed gas permeable barrier and a glass cover.This hypoxic cancer on-a-chip technology can be used to predict drug efficacy to facilitate patient specific anticancer drug prescription. And it's also expected to enable a quick diagnosis of aggressive cancers. To assist in the preparation of a three milliliter neutralized collagen pre-gel solution, cut 30 milligram collagen sponges into a five by five millimeters squared pieces.Place the pieces into a sterile 10 milliliter glass vial and add 2.4 milliliters of 0.2 micron syringe filter 0.1 normal hydrochloric acid to the vial for a three-day incubation at four degrees Celsius and 15 revolutions per minute. After the digestion, strain any undigested collagen particles through a 40 micron cell strainer and store the acidic collagen solution at four degrees Celsius for up to seven days. To adjust the pH of the 1%neutralized collagen pre-gel solution, add 30 microliters of phenol red solution to a final concentration of 1%and 300 microliters of 10X PBS to a final concentration of 10%After mixing and centrifugation, use one normal sodium hydroxide to neutralize the pH to seven, verifying the color change and add distilled water to obtain a total volume of three milliliters.Then store the pH adjusted 1%neutralized collagen pre-gel solution at four degrees Celsius for use within three days. To precheck the gelation of the neutralized collagen pre-gel solution, use a positive displacement pipette to add 50 microliters of collagen droplets to a small dish and incubate the droplets in a 37 degrees Celsius incubator for one hour. At the end of the incubation, check whether the collagen has changed from a transparent color to an opaque white.Tilt the container to confirm that the collagen is adhere to the bottom of the container. And pour PBS onto the droplet to confirm that the collagen construct does not break in solution. For 3D printing of a sacrificial PEVA mold, click File and save file type as STL to convert the 3D CAD file into an STL file and click Option and output form as ASCII to generate the G-code.To import the generated STL file, click File and open STL file and select the saved STL file. To automatically generate the G-code of the sacrificial PEVA mold, select the slice model of the STL-CAD exchanger. Then to generate printing paths for the chip fabrication, use a 50 gauge precision nozzle at a pneumatic pressure of 500 kilopascals at 110 degrees Celsius to print the sacrificial PEVA mold onto a sterile adhesive hydrophilic histology slide.To cast the PDMS barrier, mixed six milliliters of PDMS base elastomer and 600 microliters of curing agent for five minutes in a plastic reservoir and load the homogeneously blended solution into a 10 milliliter disposable syringe. Equipped the syringe with a 20 gauge plastic tapered dispense tip and fill the sacrificial PEVA mold with the blended PDMS solution. The blended PDMS will fill this sacrificial PEVA mold with a convex surface and the barrier will be higher than that of the mold.After curing the PDMS barrier in a 40 degrees Celsius oven for over 36 hours to avoid melting the PEVA, use a pair of precision tweezers to detach the sacrificial PEVA mold and sterilize the gas permeable barrier at 120 degrees Celsius in an autoclave. To mix the solution with cancer cells, resuspend each type of collected cell pellet in 20 microliters of culture medium and add one milliliter of 1%neutralized collagen pre-gel solution into each of the resuspended cell suspensions on wet ice with gentle mixing. Use a positive displacement pipette to mix each cell suspension.When homogeneous solutions are obtained, use a positive disposable pipette to transfer the cell encapsulated collagen bioinks into individual three milliliter disposable syringes and store the syringes at four degrees Celsius until 3D cell printing. For 3D printing of cancer-stroma concentric rings, convert the appropriate 3D CAD file into an STL file format and use an STL-CAD exchanger to generate a G-code of the cancer-stroma concentric rings. Load the cell encapsulated collagen bioinks into the 3D printer head and set the temperature of the head and plate to 15 degrees Celsius.Load the generated printing path on the control software of the 3D printer and click Start to print the collagen bioinks onto the gas permeable barrier according to the loaded G-code with an 18 gauge plastic needle at a pneumatic pressure of approximately 20 kilopascals at 15 degrees Celsius. At the end of every printing operation, manually place a sterilized 22 by 50 millimeter glass cover on top of the gas permeable barrier to generate the hypoxic gradient. After generating three hypoxic cancer-on-chips transfer the chips to a 37 degrees Celsius incubator for one hour to crosslink the collagen bioinks.When all of the hypoxic cancer-on-a-chips have been printed, gently rubbed the cover glasses on top of the gas permeable barriers with a cell scraper for tight bonding. To refresh cell culture medium to the chips without detaching the cancer construct, tilt the chips and use a pipette to introduce 1.5 milliliters of endothelial cell growth medium to the side of each chip. The hypoxic cancer-on-a-chip was designed in the form of concentric rings to mimic the radial oxygen diffusion and depletion observed in cancer tissues.After defining the control volume of a space in which oxygen is diffused and consumed by cells, an appropriate cellular density for central hypoxia generation can be determined through computational finite element analysis. Upon 3D cell printing, a compartmentalized cancer-stroma concentric ring structure can be created to reproduce the anatomical features of the solid cancer. Quantitatively, the post-printing cell viability is typically greater than 96%confirming that the manufacturing conditions are appropriate for cancer and stromal cells.In this representative analysis, two groups were compared according to the presence and absence of the oxygen gradient to verify the effects of a hypoxic gradient on cancer progression. Under both conditions mature CD31 positive endothelial cells were present within the peripheral regions, indicating that spatially patterned living constructs were produced using 3D bioprinting technology. Compared to the oxygen gradient negative condition the gradient positive condition demonstrated a hypoxic gradient, indicating the gradual expression of HIF1 alpha.SHMT2 positive pseudopalisaded cells and SOX2 positive pluripotent cells were also observed, indicative of the presence of aggressive pathophysiological features of solid cancer. The hypoxic cancer-on-a-chip is a useful tool for investigating the pathophysiological characteristics of solid cancers and the dynamic crosstalk between cancer cells and tumorigenesis promoting microenvironment. As the methodology can be adapted for a patient-specific drug design in a reasonable timeframe, this approach is expected to bridge the gap between in vivo and in vitro models of cancer.

3d-cell-printed-hypoxic-cancer-on-chip-for-recapitulating-pathologic

Research

JoVE Journal

Bioengineering

4.5K vues.  Pohang University of Science and Technology (POSTECH). L’hypoxie est un facteur clé du développement du cancer qui induit une instabilité génomique et une tumorigenèse. Nous démontrons une méthode pour générer une hypoxie centrale dans un cancer solide in vitro basée sur la technologie de bioimpression 3D. En utilisant cette méthode, un gradient radio hypoxique peut être reproduit à l’aide d’une stratégie simple qui combine une barrière perméable au gaz imprimée en 3D et un couvercle en verre.Cette technologie sur pu...