The present invention disclosed a shape memory and pH responsive hydrogel based on medium chain length poly-3-hydroxyalkanoates-co-polyethylene glycol methacrylate (mcl-PHA-PEGMA) macromer that cross-linking with an acrylic acid. The shape memory and pH responsive hydrogel according to the present invention is able to load a variety of hydrophilic or lipophilic pharmaceutical compounds into it polymeric networks and function as a drug delivery system. The mcl-PHA-PEGMA macromer is synthesized by enzymatic catalysis followed by the free radical polymerization process with acrylic acid as the cross-linker.