Folate-Modified Drug-Carrying Micelles With pH-Responsiveness for Curcumin-Targeted Delivery

A predrug delivery system combining tumor-targeting and pH-responsive features was synthesized using baicalin (BAI), polyethylene glycol (PEG), and folic acid (FA). BAI and PEG were linked via esterification to create pH-sensitive ester bonds (-COO-) that facilitate drug release in acidic environments, while FA was attached to PEG through substitution. This system, named FA-PEG-COO-BAI (FPB), encapsulated curcumin (CUR) to form drug-loaded micelles. The impact of drug-loading conditions, such as sonication duration and initial drug dosage, on CUR/FA-PEG-COO-BAI encapsulation efficiency and drug release was investigated. In vitro studies demonstrated a maximum encapsulation rate of (73.09 +/- 3.31)% and a drug-loading rate of (11.90 +/- 0.69)%. Drug release from CUR/FA-PEG-COO-BAI micelles accelerated as pH decreased, confirming pH-responsive behavior. Cellular uptake and antitumor assays suggested effective tumor targeting and inhibition of proliferation. Hemolysis and cell viability assays indicated low toxicity. These findings underscore the potential of CUR/FA-PEG-COO-BAI micelles for controlled drug release and targeted therapy.