In the present work, an iridium (Ir) complex loaded theranostic nanoplatform was designed for high-efficiency triple-negative breast cancer (TNBC) therapy. For this purpose, the Ir complex was firstly loaded on a photothermal agent of gold nanostars (GNS) by simply mixing followed by functionalization using a urokinase-type plasminogen activator receptor (uPAR) targeted polyetherimide-AE105 peptide conjugate (P-AE105) with the formation of GNS@Ir@P-AE105. It was demonstrated that the resultant GNS@Ir@P-AE105 was a multifunctional nanoplatform with advantages of (1) NIR laser controlled release of the Ir complex; (2) precise delivery of the Ir complex to TNBC cells; (3) excellent photothermal (PT)/photoacoustic (PA)/X-ray computed tomography (CT) tri-modal imaging ability; and (4) a synergistic photothermal-chemotherapeutic effect. An in-depth investigation of the mechanism revealed that binding forces of the Ir complex–GNS and P-AE105–GNS were significantly diminished upon NIR laser irradiation, which conferred an NIR laser-responsive Ir complex release property to the nanoplatform. Moreover, the nanoplatform exerted high efficiency anti-TNBC effects via a ROS-induced p53 apoptotic pathway. Specifically, combinational photothermal-chemotherapeutic treatments stimulated intracellular ROS generation, which significantly up-regulated apoptotic-relative p53 gene expression either by causing severe DNA damage or inducing an arrest effect on the sub-G1 phase of the cell cycle. Taken together, our work provides a novel theranostic nanoplatform for efficient and simultaneous diagnosis and therapy of TNBC.
Pancreatic ductal adenocarcinoma (PDAC) is one of the leading causes of cancer death. Early detection of precancerous pancreatic intraepithelial neoplasia (PanIN) tissues is an urgent challenge to improve the PDAC prognosis. Here, a urokinase-type plasminogen activator receptor (uPAR)-targeted magnetic resonance (MR)/near-infrared fluorescence (NIRF) dual-modal nanoprobe dendron-grafted polylysine (DGL)-U11 for ultra-early detection of pancreatic precancerosis is reported. Because of its good biocompatibility and biodegradability, globular architecture, and well-defined reactive groups, the DGL is chosen as the platform to load with a pancreatic tumor-targeting peptide U11, a magnetic resonance contrast agent Gd 3+ -diethylene triamine pentaacetic acid, and a near-infrared fluorescent cyanine dye Cy5.5. The nanoprobe DGL-U11 has several preferable characteristics, such as active peptide targeting to activator receptor, good biocompatibility, dual-modal imaging diagnosis, and well controlled diameter in a range of 15–25 nm. Upon incorporation of the active U11 peptide target to the overexpressed activator receptor uPAR, the targeted nanoprobe DGL-U11 can increase to the earlier PanIN-II stage through in vivo NIRF imaging. Labeled with both MR and NIRF bioimaging reporters, the uPAR-targeted dual-modal nanoprobe is very effective in the targeted imaging of precancerous PanINs and PDAC lesions with high sensitivity and spatial resolution, providing a promising platform to the ultra-early detection of PDAC.
Cardiac fibrosis is one of the common pathological processes in many cardiovascular diseases characterized by excessive extracellular matrix deposition. SerpinE2 is a kind of protein that inhibits peptidase in extracellular matrix and up-regulated tremendously in mouse model of cardiac fibrosis induced by pressure-overloaded via transverse aortic constriction (TAC) surgery. However, its effect on cardiac fibroblasts (CFs), collagen secretion and the underlying mechanism remains unclear. In this study, DyLight® 488 green fluorescent dye or His-tagged proteins were used to label the exogenous serpinE2 protein. It was showed that extracellular serpinE2 translocated into CFs by low-density lipoprotein receptor-related protein 1 (LRP1) and urokinase plasminogen activator receptor (uPAR) of cell membrane through endocytosis. Knockdown of LRP1 or uPAR reduced the level of serpinE2 in CFs and down-regulated the collagen expression. Inhibition of the endocytosis of serpinE2 could inhibit ERK1/2 and β-catenin signaling pathways and subsequently attenuated collagen secretion. Knockdown of serpinE2 attenuates cardiac fibrosis in TAC mouse. We conclude that serpinE2 could be translocated into cardiac fibroblasts due to endocytosis through directly interact with the membrane protein LRP1 and uPAR, and this process activated the ERK1/2, β-catenin signaling pathways, consequently promoting collagen production.