CD44-targeted hyaluronic acid-podophyllotoxin micelles with dual-stimuli responsiveness for lung cancer therapy

MST and CD quantitatively confirmed that the flexible ADH-DTDPA spacer preserves strong CD44 binding ( K D  = 15.3 μM). • HPMs showed pH/redox-triggered release, with 78.2% payload release in 72 h under tumor-mimicking conditions. • HPMs achieved superior antitumor efficacy at a lower dose while reducing systemic toxicity in vivo . Clinical application of podophyllotoxin (PPT) is significantly hampered by poor aqueous solubility and considerable systemic toxicity. Herein, we engineered dual-targeting and dual-cleavable prodrug micelles (HPMs) by conjugating PPT to hyaluronic acid (HA) backbone via a flexible, dual-responsive spacer, adipic dihydrazide–3,3′-dithiodipropionic acid (ADH-DTDPA). In vitro , HPMs demonstrated efficient CD44-mediated internalization in NCI-H1299 cells and rapidly disassembled under tumor microenvironment (TME) conditions (pH 5.0/GSH). Crucially, microscale thermophoresis (MST) provided quantitative evidence of the targeting mechanism, revealing a high binding affinity ( K D  = 15.3 μM) for the CD44 receptor. In vivo , this design achieved effective accumulation of the micelles at tumor sites. Notably, HPMs (10 mg/kg) achieved superior tumor inhibition compared to free PPT (15 mg/kg) without inducing hepatotoxicity or nephrotoxicity. These findings provide a safe delivery strategy to overcome the clinical limitations of PPT and offer quantitative molecular insights into the rational design of targeted nanomedicines for lung cancer therapy. Download: Download high-res image (244KB) Download: Download full-size image