2.2.4 Elaboration of Gelatin hydrogel loaded with PDA-PAR30 NPs (Gel-PDA-PAR)
Gelatin hydrogel was prepared with gelatin type A at 6% w/v in PBS as control (Gel-PBS). As PDA-PAR30 NPs were prepared in Tris buffer, Gel-PDA-PAR30 composite hydrogel was prepared in mix PBS/Tris at different ratios. For example, Gel-PDA-PAR30 is prepared by adding directly PDA-PAR30 NPs in Tris buffer solution to gelatin type A powder. In this condition PDA-PAR30 NPs were non diluted in the hydrogel. Then Gel-PDA-PAR30 1:2 is prepared by first diluting PDA-PAR30 NPs in Tris buffer solution with PBS at a ratio 1:1 (Tris/PBS) (V/V) and then dissolving gelatin powder in this solution. The same method is used to prepare the other formulations. Then Gelatin solution is heated at +40-50°C until complete solubilization. After that, microbial- Transglutaminase (TGA, enzymatic crosslinker) prepared in PBS at 20% w/v is added in a ratio 1 to 5 (200µL of TGA for 1000µL of gelatin). After a mixing step, 200 µL gelatin solution are poured into molds or 48 wells-plate. This crosslinking step is performed overnight at +4°C. Finally, hydrogels are treated with UV light for 15 minutes before being stored at 4°C prior to use.