Gelatin gel from porcine skin

Collagen type I (COL) was obtained in our laboratory from scales of freshwater fish Esox lucius (Dejguny Lake, Poland) [39 (link)]. Gelatin (GEL) from porcine skin, hydroxyethyl cellulose (HEC), gellan gum (GG), xanthan gum (XG), 1-ethyl-3(3-dimethylaminopropyl) carbodiimide (EDC), N-hydroxysuccinimide (NHS), Tween 80, Folin–Ciocalteu reagent and gallic acid were acquired from Sigma-Aldrich (Poznan, Poland). The hydroglycolic Calendula officinalis flower extract was obtained from Provital S.A. (Barcelona, Spain). All the other reagents were obtained from Avantor Performance Materials Poland S.A. (Gliwice, Poland). All used chemicals were of analytical grade.

Gelatin (Gel) from porcine skin was purchased from Sigma-Aldrich (Shanghai, China). Dextran (Dex, Mw = 70 KDa) was purchased from J&K (Beijing, China). Methacrylic anhydride, sodium periodate, ethylene glycol, dopamine hydrochloride, ferric chloride hexahydrate (FeCl₃ 6H₂O), kartogenin (KGN) and photo-initiator 2-hydroxy-4’-(2-hydroxyethoxy)-2-methylpropiophenone (Irgacure 2959) were purchased from Aladdin Industrial Corporation (Shanghai, China). BMSCs were purchased from Guangzhou Chuangseed Biomedical Materials Co., Ltd. All other chemical reagents were purchased from Sigma-Aldrich and used without further purification.