Table 1.

Biomaterials implemented in cardiac microphysiological systems

	Advantages	Disadvantages	Examples with References
Natural
Mammalian ECM-derived hydrogels	• Tunable elastic modulus	• Difficult to decouple elastic modulus and ECM ligand	• Matrigel (52, 146, 158)
	• Naturally adhesive to cells and amenable to cellular remodeling	• Certain isolated proteins (fibronectin, etc.) are expensive	• Gelatin (116, 125, 156)
	• Compatible with 2-D and 3-D tissue engineering	• Limited range of elastic moduli	• Fibrin (24, 28, 196)
	• Physiological
Nonmammalian ECM-derived hydrogels	• Tunable elastic modulus	• Not physiological	• Chitosan (41)
	• Easier to decouple mechanical properties and ECM ligand	• Limited range of elastic moduli	• Alginate (1)• Silk (140, 175)
	• Some are naturally adhesive to cells and amenable to cellular remodeling
	• Relatively compatible with 2-D and 3-D tissue engineering
	• Relatively inexpensive
ECM from decellularized tissues	• Closely mimic the chemical and mechanical properties of native ECM	• Not tunable• Difficult to acquire• Highly heterogeneous and variable	• Decellularized rat and pig heart slices (25)• Solubilized decellularized ECM (59, 176)
Synthetic
Elastomers	• Easy to decouple elastic modulus and ECM ligand	• Not naturally adhesive to cells or amenable to cellular remodeling	• Polydimethylsiloxane (31, 54, 111, 134, 147)
	• Compatible with 2-D tissue engineering• Relatively inexpensive	• Not compatible with 3-D tissue engineering
	• Extensive range of elastic moduli
Hydrogels	• Easy to decouple elastic modulus and ECM ligand	• Not naturally adhesive to cells or amenable to cellular remodeling	• Polyacrylamide (11, 59, 69, 119, 176)
	• Compatible with 2-D tissue engineering• Relatively inexpensive	• Not compatible with 3D tissue engineering	• Polyethylene glycol (86, 87)

2-D, two-dimensional; 3-D, three-dimensional; ECM, extracellular matrix.