PH response type 3D printing hydrogel dressing as well as preparation method and application thereof

The invention belongs to the field of biomedical materials, and discloses a pH response type 3D printing hydrogel dressing and a preparation method and application thereof.The hydrogel dressing is obtained by assembling a prepared color changing unit, a seepage traction module, a hydrogel layer and a transparent dressing patch; the color changing unit is completed by extracting anthocyanin and dyeing the anthocyanin; the seepage traction module is prepared by taking polyether polyol, water, a catalyst and a foam stabilizer as main raw materials through a one-step method; the hydrogel layer is obtained by taking gelatin, methacrylic anhydride, sodium alginate, a growth factor and a photoinitiator as main raw materials, performing 3D printing, crosslinking with an anhydrous calcium chloride solution and soaking with a metal cation aqueous solution; according to the hydrogel dressing prepared through the 3D printing technology, CAD modeling can be conducted according to the depth of a wound, the printed hydrogel