Synthesis and Characterization of PEG-DA Hydrogel

Sodium periodate (NaIO4, > 99.8%) was obtained from Acros Organics (Fair Lawn, NJ). 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide 98% (MTT) was purchased from Alfa Aesar (Ward Hill, MA). Phosphate buffer saline (PBS), tetraethyl orthosilicate (TEOS, 99.8%), ethanol (200 proof), sodium hydroxide, and acetic acid (Glacier) were purchased from Fisher Scientific Co. (Pittsburgh, PA). Histology mounting medium Polyfreeze, Trichrome Stain (Masson) Kit, Bouin’s solution, and Weigert’s iron hematoxylin solution were purchased from Sigma-Aldrich (St. Louis, MO). Anti-CD163 antibody (ab87099), goat anti-rabbit IgG H&L (Alexa Fluor 488) (ab150077), anti-CD68 antibody (ab125212), and goat anti-rabbit IgG H&L (Alexa Fluor 647) were purchased from Abcam (Cambridge, MA). 4,6-Diamidino-2-phenylindole (DAPI) was obtained from Invitrogen (Grand Island, NY). PEG-DA (Figure S1) was prepared using an 8-armed PEG (MW = 20 kDa, JenKem USA, TX) while following previously published protocols (22 (link), 30 (link)).