Table 2.

An overview of “Biomaterials” section, synthetic polymers.

Synthetic# , ##		Pro	Contra
Polyethers	Polyethyleneglycol (PEG)	‐ FDA approved ‐ High water content hydrogel after crosslinking	‐ Adhesive capacity has to be introduced ‐ Biodegradability has to be improved###
Polyesters	Poly(epsiloncaprolacton) (PCL)	‐ FDA approved ‐ Biodegradable (lipases esterases)	‐ Adhesive capacity has to be introduced ‐ Relatively hydrophobic
Polyacrylates	Poly(2‐hydroxyethylmethacrylate) (PHEMA)	‐Functional groups for introducing adhesive functionality ‐ Well hydrated ‐ Biodegradable (75% in 17 days)	Adhesive capacity has to be introduced
Polyacrylamides	Poly(acrylamide) (PA)	‐ Tunable stiffness ‐ Protocols for controlled protein coupling available	‐ Adhesive capacity has to be introduced ‐ Hydrogel precursor is toxic (= not biodegradable)
Polypeptides	Puramatrix™	‐ Intrinsic nanofiber scaffold hence 3D ‐ Encapsulation of cells under physiological conditions ‐ Easily modified at amino acid level with adhesive sequence ‐ Injectable ‐ Biodegradable ‐ Softer than fibrin and collagen gels

Background information is indicated by symbols.

^#Synthetic polymers are more strictly defined than their natural counterparts and purity of components may guarantee that no pathogens are present.

^##Often microfibers are frequently used, but actually, this is a 2D environment.

^###For instance, by incorporating matrix metalloproteinase cleavable motifs.