TABLE 1.

Comparison of in vitro compression devices.

Methods of force application	Weight of the piston on the top Tse et al. (2012)	Weight of the cube filled with iron ball bearings Kim et al. (2017)	Weight of the piston on the top Kalli et al. (2019)	Cylindrical weight on the top Morikura and Miyata (2019)	Cylindrical weight on the top Morikura and Miyata (2021)	Air pressure applied via a bioreactor device Novak et al. (2020)	Weight of gels on the top [this work]
Compression force	5.8 mmHg	5.8 mmHg (∼0.773 kPa)	4 mmHg	0.77 kPa	0.77 kPa	3.9–6.5 kPa dynamically	0.08–0.24 mmHg
Compression force applied duration	16 h	24 h	16 h	8 and 32 h	a cycle of 4 h on/4 h off	24 and 72 h	1, 2, 4, and 24 h
Cell types	Breast cancer cells	Breast cancer cells	Brain cancer cells	Melanoma cells	Melanoma cells	Ovarian cancer cells	Breast cancer cells
Cell culture condition	Cells sandwiched between gels	Cells embedded in agarose	Spheroids embedded in agarose	Cells embedded in collagen	Cells embedded in collagen	Cells embedded in agarose/collagen	Cells sandwiched between gels
Real-time observation	No	No	No	Yes	Yes	No	Yes
Single cell resolution	No	No	No	No mentioned	No mentioned	No	Yes
Hydrogel digest for cell harvest	Not required	Required	Required	Required	Required	Required	Not required