“…Natural materials include collagen ( Chang et al, 2011 ), gelatin ( Chang et al, 2020 ), fibrin ( Rabbani et al, 2017 ), silk fibroin ( Qing et al, 2018 ), alginate ( Yang et al, 2018 ), gellan gum, hyaluronic acid (HA) ( Yazdani et al, 2019 ), chitosan ( Kim et al, 2016 ), Matrigel ( Wang et al, 2020b ); while synthetic polymer materials include poly caprolactone (PCL) ( Zhang et al, 2017 ), polydimethylsiloxane (PDMS) ( McKee et al, 2017 ), polyethylene oxide (PEO) ( Evrova et al, 2016 ), polylactic acid (PLA) ( Gandolfi et al, 2020 ), poly lactic acid-glycolic acid (PLGA) ( Swanson et al, 2020 ), polyvinyl alcohol (PVA) ( Kalachaveedu et al, 2020 ), polyethylene glycol (PEG), tribasic calcium phosphate (TCP) ( Ying et al, 2020 ). Biomaterials used for 3D bioprinting are called “bio-inks.”…”