Photocrosslinked GelMA-AgNP Constructs

GelMA constructs were prepared by adding 50% w/w of GelMA stock solution, 48% PBS, 1% of 50 mM tris(2,2-bipyridyl) dichlororuthenium(II) hexahydrate (Ru; Cat. No. 544981; Sigma-Aldrich, Auckland, New Zealand), and 1% of 500 mM sodium persulphate (SPS; Cat. No. 216232; Sigma-Aldrich, Auckland, New Zealand). Stock solutions of 50 mM Ru (MW = 748.63 g/mol) and 500 mM SPS (MW = 238.1 g/mol) were made in PBS. All solutions were sterilized with a 0.22 μm filter prior to use. Different gel consistencies (stiff, standard, and soft) were obtained by preparing different concentrations of the stock GelMA solution as per Table S2A in the Supplementary Materials. In the GelMA-AgNP constructs, the volume of AgNPs to be used was deduced from the total amount of PBS added. Constructs were pipetted into well plates and photo cross-linked for 3 min using visible light (Wavelength = 400–450 nm) at 30 mW/cm².