Genipin

PDMS (Sylgard 184) was obtained from Dow Corning (Midland, USA). PLA was purchased from Lakeshore Biomaterials Inc. (AL, USA). Cell counting kit (CCK-8) and STZ were purchased from AbMole BioScience (TX, USA). Gel (from cold water fish skin and from porcine skin), FITC, phosphate buffer, and deuterium oxide (D₂O, D > 99.9%) were purchased from Sigma-Aldrich (MO, USA). Ehrlich’s reagent was purchased from BioTechnology Co Ltd. (Shanghai, China). Acetic acid, sodium carbonate anhydrous (Na₂CO₃), and dibasic sodium phosphate (Na₂HPO₄) were obtained from Sinopharm Chemical Reagent Co Ltd. (Beijing, China). Insulin (short-, intermediate-, and long-acting types) was purchased from Wanbang Biopharmaceuticals Co. Ltd. (Jiangsu, China). HA (M_w ≈ 350,000 Da) was purchased from Toronto Research Chemicals Inc. (Toronto, Canada). BDDE (M_w = 202.25 Da) was purchased from Adamas Reagent Co. Ltd. (Basel, Switzerland). Genipin was purchased from J&K Scientific (Beijing, China). Mouse fibroblast cell lines (L-929 cells) were purchased from iCell Bioscience (Shanghai, China), and female Balb/c mice were obtained from the Institute of Laboratory Animal Sciences (Beijing, China). Aqueous solutions were carried out using ultrapure water from a reverse osmosis membrane system, unless otherwise stated.