AIMS: Breast cancer is the second leading cause of death worldwide. Conventional chemotherapeutic therapies lack the specific targeting effect toward the cancerous cells resulting in extensive side effects. Our current study endeavors to prepare novel bioinspired folic acid-functionalized caffeic acid (CA)-loaded casein nanoparticles (CS NPs) for curbing breast cancer. METHODS: CA-CS NPs were prepared by simple coacervation method followed by lyophilization. Functionalized CS NPs were achieved using folic acid as the targeting moiety. Entire comparative characterization between unconjugated and conjugated NPs were implemented in terms of size, polydispersity index, surface charge, H-NMR, surface morphology, drug release, sterilization, cytotoxicity, and animal studies. RESULTS: Conjugated NPs attained PS = 157.23 ± 2.64 nm, PDI = 0.309 ± 0.199, ZP = -25.53 ± 2.31 mV and IC50 = 40 ± 2.9 µg/ml. Significant reduction in the biochemical marker levels of Carcino-embryonic antigen, carbohydrate antigen 15-3, and malondialdehyde while increased superoxide dismutase levels were achieved in the tumor -induced rats treated by the conjugated NPs. Histopathological examinations showed great improvement in the mammary and necrotic regions. CONCLUSION: The present work paves the road of 'back to nature' approach in designing biocompatible bioinspired conjugated nanocarriers for the diagnosis and treatment of various diseases.