Localized delivery,comparing to systemic drug administration,offers a unique alternative to enhance efficacy,lower dosage,and minimize systemic tissue toxicity by releasing therapeutics locally and specifically to the site of interests.Herein,a localized drug delivery platform(“plum-pudding”struc-ture)with controlled release and long-acting features is developed through an injectable hydrogel(“pud-ding”)crosslinked via self-assembled triblock polymeric micelles(“plum”)to help reduce renal interstitial fibrosis.This strategy achieves controlled and prolonged release of model therapeutics in the kidney for up to three weeks in mice.Following a single injection,local treatments containing either anti-inflammatory small molecule celastrol or anti-TGFβ antibody effectively minimize inflammation while alleviating fibrosis via inhibiting NF-κB signaling pathway or neutralizing TGF-β1 locally.Importantly,the micelle-hydrogel hybrid based localized therapy shows enhanced efficacy without local or systemic toxicity,which may represent a clinically relevant delivery platform in the management of renal interstitial fibrosis.