ABSTRACT
Objective: The study aimed to monitor fetuses with tetralogy of Fallot (TOF) after prenatal counseling and how it influenced the decision of parents to terminate the pregnancy. Methods: Fetuses with isolated TOF diagnosed between January 2019 and December 2021 were prospectively enrolled. The follow-up period extended until termination or 6 months after the operation. Results: Of the 1,026 fetuses diagnosed with cardiac defects, 129 were identified to have isolated TOF and completed the follow-up. A total of 55 (42.6%) fetuses were terminated, with larger maternal age (odds ratio: 0.893, 95% confidence interval: 0.806-0.989, P = 0.031) as the protective factor. The maternal anxiety score, gestational weeks, and pulmonary-to-aortic-diameter ratio lost significance in multivariate analysis. Subjectively, the two most common reasons for terminating the pregnancy were worries about the prognosis (41.8%) and concerns about the possible suffering of the unborn child (18.2%). The prenatal diagnosis was accurate in 73 of the 74 (98.6%) live births. Out of the 64 live births that underwent surgical repair in our center, 57 (89.1%) received primary repair, with a median age of 104 days, and 49 (76.6%) underwent valve-sparing repair. No perioperative death occurred. Conclusions: Termination for fetuses with TOF remains common in China. Live births with TOF can be safely and effectively managed.
ABSTRACT
Bioprosthetic heart valves (BHVs) used in clinics are fabricated via glutaraldehyde (GLUT) crosslinking, which results in cytotoxicity and causes eventual valve calcification after implantation into the human body; therefore, the average lifetime and application of BHVs are limited. To address these issues, the most commonly used method is modification with amino acids, such as glycine (GLY), which is proven to effectively reduce toxicity and calcification. In this study, we used the l-glutathione (GSH) in a new modification treatment based on GLUT-crosslinked bovine pericardium (BP) as the GLUT + GSH group, BPs crosslinked with GLUT as GLUT-BP (control group), and GLY modification based on GLUT-BP as the GLUT + GLY group. We evaluated the characteristics of BPs in different treatment groups in terms of biomechanical properties, cell compatibility, aldehyde group content detection, and the calcification content. Aldehyde group detection tests showed that the GSH can completely neutralize the residual aldehyde group of GLUT-BP. Compared with that of GLUT-BP, the endothelial cell proliferation rate of the GLUT + GSH group increased, while its hemolysis rate and the inflammatory response after implantation into the SD rat were reduced. The results show that GSH can effectively improve the cytocompatibility of the GLUT-BP tissue. In addition, the results of the uniaxial tensile test, thermal shrinkage temperature, histological and SEM evaluation, and enzyme digestion experiments proved that GSH did not affect the ECM stability and biomechanics of the GLUT-BP. The calcification level of GLUT-BP modified using GSH technology decreased by 80%, indicating that GSH can improve the anti-calcification performance of GLUT-BP. Compared with GLUT-GLY, GLUT + GSH yielded a higher cell proliferation rate and lower inflammatory response and calcification level. GSH can be used as a new type of anti-calcification agent in GLUT crosslinking biomaterials and is expected to expand the application domain for BHVs in the future.
ABSTRACT
BACKGROUND: Cell therapy is a promising strategy for tissue regeneration. Key to this strategy is mobilization and recruitment of exogenous or autologous stem/progenitor cells by cytokines. However, there is no effective cytokine delivery system available for clinic application, in particular for myocardial regeneration. The aim of this study was to develop a novel cytokine delivery system that is stable in solution at physiological pH. METHODS: Four groups of self-assembled chitosan oligosaccharide/heparin (CSO/H) nanoparticles were prepared with various volume ratios of chitosan oligosaccharide to heparin (5:2, 5:4, 4:15, 1:5) and characterized by laser diffraction, particle size analysis, and transmission electron microscopy. The encapsulation efficiency and loading content of two cytokines, ie, stromal cell-derived factor (SDF)-1α and vascular endothelial growth factor (VEGF) were quantified using an enzyme-linked immunosorbent assay. The biological activity of the loaded SDF-1α and VEGF was evaluated using the transwell migration assay and MTT assay. The dispersion profiles for the cytokine-loaded nanoparticles were quantified using fluorescence molecular tomography. RESULTS: CSO/H nanoparticles were prepared successfully in solution with physiological pH. The particle sizes in the four treatment groups were in the range of 96.2-210.5 nm and the zeta potential ranged from -29.4 mV to 24.2 mV. The loading efficiency in the CSO/H nanoparticle groups with the first three ratios was more than 90%. SDF-1α loaded into CSO/H nanoparticles retained its migration activity and VEGF loaded into CSO/H nanoparticles continued to show proliferation activity. The in vivo dispersion test showed that the CSO/H nanoparticles enabled to VEGF to accumulate locally for a longer period of time. CONCLUSION: CSO/H nanoparticles have a high cytokine loading capacity and allow cytokines to maintain their bioactivity for longer, are stable in an environment with physiological pH, and may be a promising cytokine delivery system for tissue regeneration.
