李泽夫
中国医学科学院阜外医院 结构性心脏病三病区
Transcatheter intervention has been the preferred treatment for congenital structural heart diseases by implanting occluders into the heart defect site through minimally invasive access. Biodegradable polymers provide a promising alternative for cardiovascular implants by conferring therapeutic function and eliminating long-term complications, but inducing in situ cardiac tissue regeneration remains a substantial clinical challenge. PGAG (polydioxanone/poly (l-lactic acid)-gelatin-A5G81) occluders are prepared by covalently conjugating biomolecules composed of gelatin and layer adhesive protein-derived peptides (A5G81) to the surface of polydioxanone and poly (l-lactic acid) fibers. The polymer microfiber-biomacromolecule-peptide frame with biophysical and biochemical cues could orchestrate the biomaterial-host cell interactions, by recruiting endogenous endothelial cells, promoting their adhesion and proliferation, and polarizing immune cells into anti-inflammatory phenotypes and augmenting the release of reparative cytokines. In a porcine atrial septal defect (ASD) model, PGAG occluders promote in situ tissue regeneration by accelerating surface endothelialization and regulating immune response, which mitigate inflammation and fibrosis formation, and facilitate the fusion of occluder with surrounding heart tissue. Collectively, this work highlights the modulation of cell-biomaterial interactions for tissue regeneration in cardiac defect models, ensuring endothelialization and extracellular matrix remodeling on polymeric scaffolds. Bioinspired cell-material interface offers a highly efficient and generalized approach for constructing bioactive coatings on medical devices.
Advanced science (Weinheim, Baden-Wurttemberg, Germany) 2024
Although the use of bioabsorbable occluder is expected to reduce the risk of metal occluder-related complications, it has not been approved due to incomplete degradation and new complications. Novel fully bioabsorbable occluders were designed to overcome such limitations. The aim of this study was to investigate the efficacy and safety of a fully biodegradable occluder in patients with ventricular septal defects. 125 patients with perimembranous ventricular septal defect (VSD) larger than 3 mm were screened from April 2019 to January 2020 in seven centers. 108 patients were enrolled and randomized into the bioabsorbable occluder group (n = 54 patients) and nitinol occluder group (n = 54). A non-inferiority design was utilized and all patients underwent transcatheter device occlusion. Outcomes were analyzed with a 24-month follow-up. All patients were successfully implanted and completed the trial. No residual shunt >2 mm was observed during follow-up. Transthoracic echocardiography showed a hyperechoic area corresponding to the bioabsorbable occluder which decreased primarily during the first year after implantation and disappeared within 24 months. Postprocedural arrhythmia was the only occluder-related complication with an incidence of 5.56% and 14.81% for the bioabsorbable and nitinol groups, respectively (P = 0.112). The incidence of sustained conduction block was lower in the bioabsorbable occluder group (0/54 vs. 6/54, P = 0.036) at 24-month follow-up. In conclusion, the novel fully bioabsorbable occluder can be successfully and safely implanted under echocardiography guidance and reduce the incidence of sustained postprocedural arrythmia. The efficacy and safety of this fully biodegradable occluder are non-inferior to that of a traditional nitinol one.
Science bulletin 2023
The treatment of myocardial infarction (MI) remains a substantial challenge due to excessive inflammation, massive cell death, and restricted regenerative potential, leading to maladaptive healing process and eventually heart failure. Current strategies of regulating inflammation or improving cardiac tissue regeneration have limited success. Herein, a hybrid hydrogel coassembled by acellular cardiac extracellular matrix (ECM) and immunomodulatory glycopeptide is developed for endogenous tissue regeneration after MI. The hydrogel constructs a niche recapitulating the architecture of native ECM for attracting host cell homing, controlling macrophage differentiation via glycopeptide unit, and promoting endotheliocyte proliferation by enhancing the macrophage-endotheliocyte crosstalk, which coordinate the innate healing mechanism for cardiac tissue regeneration. In a rodent MI model, the hybrid hydrogel successfully orchestrates a proreparative response indicated by enhanced M2 macrophage polarization, increased angiogenesis, and improved cardiomyocyte survival, which alleviates infarct size, improves wall thicknesses, and enhances cardiac contractility. Furthermore, the safety and effectiveness of the hydrogel are demonstrated in a porcine MI model, wherein proteomics verifies the regulation of immune response, proangiogenesis, and accelerated healing process. Collectively, the injectable composite hydrogel serving as an immunomodulatory niche for promoting cell homing and proliferation, inflammation modulation, tissue remodeling, and function restoration provides an effective strategy for endogenous cardiac repair.
Advanced science (Weinheim, Baden-Wurttemberg, Germany) 2023
Ventricular septal defect (VSD) is one of the commonest congenital heart diseases (CHDs). Current occluders for VSD treatment are mainly made of nitinol, which has the risk of nickel allergy, persistent myocardial abrasion and fatal arrythmia. Herein, a fully biodegradable polydioxanone (PDO) occluder equipped with a shape line and poly-l-lactic acid PLLA membranes is developed for VSD closure without the addition of metal marker. PDO occluder showed great mechanical strength, fatigue resistance, geometry fitness, biocompatibility and degradability. In a rat subcutaneous implantation model, PDO filaments significantly alleviated inflammation response, mitigated fibrosis and promoted endothelialization compared with nitinol. The safety and efficacy of PDO occluder were confirmed in a canine VSD model with 3-year follow-up, demonstrating the biodegradable PDO occluder could not only effectively repair VSD, induce cardiac remodeling but also address the complications associated with metal occluders. Furthermore, a pilot clinical trial with five VSD patients indicated that all the occluders were successfully implanted under the guidance of echocardiography and no adverse events occurred during the 3-month follow-up. Collectively, the fully bioresorbable PDO occluder is safe and effective for clinical VSD closure and holds great promise for the treatment of structural CHDs.
Bioactive materials 2023
Endothelial-to-mesenchymal transition (EndMT) plays a critical role in the flow-induced vascular remodeling process, such as pulmonary arterial hypertension (PAH) related to congenital heart disease (CHD). NBL1 (neuroblastoma suppressor of tumorigenicity 1) is a secreted glycoprotein that has been implicated in CHD-PAH by aggravating the phenotypic transformation of smooth muscle cells. However, the underlying mechanisms regarding the interplay between NBL1 and endothelial cells in CHD-PAH remain to be fully elucidated. Thus, we aimed to identify the potential effect of NBL1 on EndMT using a novel flow-associated PAH model with Nbl1 knockout rats. The phenotype of EndMT was detected using RNA sequencing and further examined using western blotting and immunostaining of pulmonary arteries. Our observations demonstrated that the novel strategy of Nbl1 knockout effectively attenuated flow-associated PAH through downregulation of EndMT to some extent. Mechanistic experiments were established on human pulmonary artery endothelial cells to confirm that EndMT was induced by NBL1 in vitro. After 7 days' stimulation with NBL1, concentrations of EndMT-related biomarkers and downstream transcription factors were quantified using RNA sequencing, western blotting, and immunocytochemistry. Both in vitro and in vivo experiments supported the imbalance of increased TGF-β (transforming growth factor-β) and dysregulation of BMP (bone morphogenetic protein) signaling by NBL1. Blocking the canonical TGF-β pathway efficiently preserved endothelial function upon NBL1 stimulation. These data suggested that NBL1 aggravated flow-associated PAH by inducing EndMT via the TGF-β and BMP signaling pathway. Thus, antagonizing NBL1 and rebalancing TGF-β and BMP signaling may be a suitable therapeutic target for CHD-PAH.
American journal of respiratory cell and molecular biology 2022
