ROS-responsive nanomicelles encapsulating celastrol ameliorate pressure overload-induced cardiac hypertrophy by regulating the NF-κB signaling pathway

Celastrol (CEL) belongs to the group of non-steroidal immunosuppressants with the potential to improve cardiac hypertrophy (CH). However, the poor biocompatibility and low bioavailability of CEL limit its <i>in vivo</i> application. This study was aimed to develop a targeted drug delivery system that can efficiently and safely deliver CEL to target tissues, providing a research basis for the application of CEL in CH therapy. A novel ROS-sensitive drug-loaded nanomicelle, dodecanoic acid (DA)-phenylboronic acid pinacol ester-dextran polymer encapsulating CEL (DBD@CEL), was synthesized using chemical synthesis. Then, the morphology, particle size, drug-loaded content, and ROS-responsive release behavior of DBD@CEL were studied. Pharmacokinetics and biocompatibility were evaluated using healthy mice. Finally, the ability and mechanism of DBD@CEL in improving CH <i>in vivo</i> were investigated using a mouse CH model. DBD@CEL was successfully prepared with a drug loading of 18.9%. It exhibited excellent stability with an average particle size of 110.0 ± 1.7 nm. Within 48 h, DBD@CEL released only 19.4% in the absence of H₂O₂, while in the presence of 1 mM H₂O₂, the release rate increased to 71.5%. Biocompatibility studies indicated that DBD@CEL did not cause blood cell hemolysis, had no impact on normal organs, and did not result in abnormal blood biochemical indicators, demonstrating excellent biocompatibility. <i>In vivo</i> studies revealed that DBD@CEL regulated the activation of NF-κB signaling, inhibits pyroptosis and oxidative stress, and thereby ameliorates CH. The ROS-responsive DBD@CEL nanodrug delivery system enhances the therapeutic activity of CEL for CH, providing a promising drug delivery system for the clinical treatment of CH.