Fig. 1

Schematic of processing the single components for the silk, tyrosinated gelatin, and human placenta ECM (SGE) composite hydrogels: A hpcECM hydrogel produced by tissue decellularization of chorionic tissue from the human placenta, followed by enzymatic digestion to solubilize hpcECM powder into a pre-hydrogel solution which forms a gel at physiological condition (37 °C, pH 7.2). B Chemical modification of bovine gelatin type B by EDC/NHS coupling of tyramine-modified amino acids to the backbone of gelatin. C (ii) Degumming Bombyx mori silk cocoon fibers using carbonate buffer (60 min boiling) followed by (iii) drying in air on aluminum foil and (iv) lithium bromide (LiBr) solubilization of silk fibers to produce a silk fibroin pre-hydrogel solution. (v) Polymerization can be chemically induced by a combination of horseradish peroxidase (HRP) and hydrogen peroxide (H₂O₂). D Mixing the three components results in SGE composite hydrogels for 3D printing and tissue engineering