Breast cancer has a high incidence among women [1] and almost all women with breast cancer should have surgery in the treatment,which can only remove the visible tumor tissues.The risk of recurrence is still very high as the residual malignant cells can not be eliminated completely.For the traditional systemic chemotherapy to prevent tumor recurrence,a continuous sustained drug release with the desired concentration at the tumor location is challenging due to the removal and sequestration by the reticuloendothelial system.Consequently,a local drug delivery depot such as implantation of a biodegradable device loaded with anti-cancer drug in the resulting cavity brought much more prominent clinical effects in the breast cancer therapy [2],in which a prolonged drug release can be achieved through the sustained drug release from the hydrogels.