A high incidence of restenosis has been reported at the site of inflammation following angioplasty and stent implantation. The anti-proliferative drug paclitaxel (PTX) could help to reduce inflammation and restenosis; however, it has poor water solubility and serious adverse side effects at high doses. Given the presence of metabolic acidosis at the site of inflammation, we hypothesized that nanoparticles that are responsive to low pH could precisely release the loaded drug at the target site. We successfully constructed pH-responsive poly(D, L-lactic-co-glycolic acid) (PLGA) nanoparticles loaded with PTX and NaHCO₃ as a pH-sensitive therapeutic agent (PTX-NaHCO₃-PLGA NPs). The NPs exhibited remarkable pH sensitivity and a good safety profile both in vitro in rat vascular smooth muscle cells and in vivo in Sprague Dawley rats after tail vein injection. In the rat model, the PTX-NaHCO₃-PLGA NPs treatment group showed suppressed intimal proliferation following balloon-induced carotid artery injury compared with that of the saline-treated control. Overall, these results demonstrate that our newly developed pH-responsive nanodrug delivery platform has the potential to effectively inhibit restenosis.

Objective: This study aimed to explore the safety and efficacy of simultaneous interventional therapy for compound congenital heart disease (CCHD) in children.Methods: In total, 155 children with CCHD who received simultaneous interventional therapy at the Children's Hospital of Chongqing Medical University between January 2007 and December 2021 were included in study. Data on clinical manifestations, transthoracic echocardiography, electrocardiogram, and follow-up were retrospectively analyzed.Results: The most common type of CCHD was atrial septal defect (ASD) combined with ventricular septal defect (VSD), accounting for 32.3% of the patients. Simultaneous interventional therapy was successfully administered to 151 children (97.4%). The pulmonary gradient of patients with pulmonary stenosis decreased from 47.3 ± 21.9 mmHg to 15.2 ± 12.2 mmHg (P < 0.05) immediately after the procedure. One patient had failed PBPV as he had residual PS >40 mmHg post procedure. The right ventricular dimension and left ventricular end-diastolic dimension significantly decreased in the first month after the procedure in patients with ASD combined with VSD. Twenty-five (16.1%) patients had mild residual shunt, which spontaneously disappeared in more than half of these patients 6 months after the procedure. The major adverse events were minimal (n = 4, 2.58%), including one patient requiring drug treatment for complete atrioventricular block and three patients receiving surgical treatment because of cardiac erosion, anterior tricuspid valve chordae rupture, and hemolysis, respectively.Conclusions: ASD combined with VSD is the most common type of CCHD in children, and simultaneous interventional therapy for CCHD in children is safe and effective with satisfactory results. Ventricular remodeling can be reversed in patients with ASD combined with VSD 1 month after the procedure. Most adverse events associated with interventional therapy are mild and manageable.