Poly (caprolactam) (nylon 6, 181110), formic acid (FA, F0507), thrombin from bovine plasma (T4648), fibrinogen from bovine plasma (F8630), streptozotocin (STZ, S0130) and gelatin from porcine skin (G1890) were purchased from Sigma-Aldrich Co. (St. Louis, MO). 1,1,1,3,3,3-Hexafluoro-2-propanol (HFIP, 003409) was purchased from Oakwood Products, Inc. (Estill, SC). Calcium chloride (CaCl2, BDH9224) and sodium chloride (NaCl, BDH9286) were purchased from VWR International (Radnor, PA). Barium chloride dihydrate (BaCl2.2H2O, BX0060-1) was purchased from EMD Millipore Corporation. Regular sodium alginate (PROTANAL LF 10/60FT) and sterile sodium alginate (Pronova SLG 100) were purchased from FMC BioPolymer Co. (Philadelphia, PA). Sucrose (8360-6) was purchased from Avantor Performance Materials, LLC. (Center Valley, PA). All reagents were used without further purification. Sulfobetaine-modified alginate (SB-alginate) was synthesized according to a previously published protocol[18 (link)].