Ros-responsive dextran-phenylboronic acid-silibinin nanoparticles for targeting delivery of BAPTA-AM to effectively eliminate calcium overload-mediated inflammatory cascades and mitochondrial apoptosis: Alleviating acute liver injury

Calcium overload in hepatocytes mediates the crosstalk and amplification loop with oxidative stress and severe inflammation that initiate pro-apoptotic and necrotic signaling pathways in acute liver injury (ALI). In this study, an N-acetylgalactosamine-modified amphiphilic dextran-silibinin conjugate (GalNAc-Dex-Sil) with ROS-sensitive phenylboronic acid (PBA) linkage was synthesized. The as-prepared amphiphilic polymer was self-assembled into GalNAc-Dex-Sil nanoparticles, which efficiently encapsulated the membrane-permeable calcium chelator BAPTA-AM (BA), achieving GalNAc-mediated hepatocyte-specific targeting and ROS-responsive release in injured hepatocytes through PBA cleavage. Accordingly, a single low-dose injection of formulation (BA: 150 μg·kg−1) significantly alleviated hepatocyte oxidative stress and inflammation, rescued dying hepatocytes, prevented further hepatocyte damage, and ultimately restored liver function in the ALI mouse model by 1) rapidly and effectively eliminating the overloaded calcium and scavenging excessive ROS via released BA to block the feed-forward vicious cycles of the cell damage, 2) inhibiting the inflammatory cascade by decreasing the expression of the key factor of the NF-κB/NLPR3 axis, 3) inhibiting the key branch of the mitochondrial apoptotic pathway (Cyt C/Bcl-2 family/caspase-3 axis) and death receptor pathway (TNFα/Caspase-8 axis), and 4) stabilizing hepatocyte membranes through the synergistic hepatoprotective effect of silibinin. Taken together, this formulation exhibited great potential as a potent and effective ALI treatment strategy.