Decellularization is a promising technique to produce natural scaffolds for tissue engineering applications. However, non-crosslinked natural scaffolds disfavor application in cardiovascular surgery due to poor biomechanics and rapid degradation. Herein, we proposed a green strategy to crosslink and functionalize acellular scaffolds via the self-assembly of copper@tea polyphenol nanoparticles (Cu@TP NPs), and the resultant nanocomposite acellular scaffolds were named as Cu@TP-dBPs. The crosslinking degree, biomechanics, denaturation temperature and resistance to enzymatic degradation of Cu@TP-dBPs were comparable to those of glutaraldehyde crosslinked decellularized bovine pericardias (Glut-dBPs). Furthermore, Cu@TP-dBPs were biocompatible and had abilities to inhibit bacterial growth and promote the formation of capillary-like networks. Subcutaneous implantation models demonstrated that Cu@TP-dBPs were free of calcification and allowed for host cell infiltration at Day 21. Cardiac patch graft models confirmed that Cu@TP-dBP patches showed improved ingrowth of functional blood vessels and remodeling of extracellular matrix at Day 60. These results suggested that Cu@TP-dBPs not only had comparable biomechanics and biostability to Glut-dBPs, but also had several advantages over Glut-dBPs in terms of anticalcification, remodeling and integration capabilities. Particularly, they were functional patches possessing antibacterial and proangiogenic activities. These material properties and biological functions made Cu@TP-dBPs a promising functional acellular patch for cardiovascular applications.
Tricuspid regurgitation (TR) has become one of the most common valve diseases. Patients with severe TR are often at high surgical mortality risk. Transcatheter tricuspid valve interventions have emerged as a promising alternative to open-heart surgery. The LuX-Valve is a novel radial force-independent transcatheter tricuspid valve replacement system. We presented here the first patient treated for symptomatic TR using the LuX-Valve replacement system in September 2018. Four-year follow-up outcomes suggested that the bioprosthesis was in normal function, with stable hemodynamics (mean transtricuspid gradient 2.55 mmHg) and the patient’s clinical symptoms were significantly improved; thus indicating that it is a safe, effective, and satisfactory case of the LuX-Valve application in treating a patient with severe TR.
1 January 2025 in American Journal of Translational Research
To evaluate the effects of 75% ethanol on the disinfection efficacy, biocompatibility, extracellular matrix (ECM) integrity, and mechanical properties of swim bladders from Hypophthalmichthys nobilis, a promising biomaterial for cardiovascular applications. Swim bladders were immersed in 75% ethanol for 30, 60, or 120 minutes, followed by phosphate-buffered saline (PBS) rinsing. Disinfection efficacy was assessed using bacterial cultures; cytotoxicity and blood compatibility were evaluated using CCK-8 assays and hemolysis tests. The decellularization efficiency, ECM integrity, and mechanical properties were analyzed through histological staining, DNA quantification, and uniaxial tensile test. 75% ethanol effectively disinfected the swim bladder with minimal cytotoxicity and good hemocompatibility. Histological staining demonstrated preservation of collagen fibers, elastin, and glycosaminoglycans (GAGs), indicating minimal impact on the ECM structure. The uniaxial tensile test revealed that ethanol immersion caused tissue dehydration and increased stiffness, but these effects were reversible after PBS rinsing, with mechanical properties returning to baseline. DNA content and tissue thickness normalized following PBS washing, suggesting that ethanol did not impair decellularization. 75% ethanol is an effective disinfectant for swim bladder biomaterials, preserving biocompatibility, ECM structure, and mechanical properties after rinsing. These findings support the use of swim bladder-derived scaffolds in cardiovascular tissue engineering applications.
Transcatheter aortic valve implantation (TAVI) has become a popular treatment for surgical high-risk patients with severe aortic stenosis (AS). Recently, we have applied TAVI to the treatment of aortic regurgitation (AR). Compared with conventional surgical procedures, TAVI is less invasive and considered a useful option for these high-risk patients. In this study, we reported a patient who underwent transapical TAVI. The patient was a 52-year-old female with Takayasu arteritis (TA) for 25 years, as well as with severe aortic regurgitation, porcelain aortas, and heart failure. Transapical TAVI successfully was accomplished without neurological complications, and heart failure immediately improved postoperatively.
Rationale: To maintain vascular patency, endothelial cells (ECs) actively regulate hemostasis. Among the myriad of pathways by which they control both fibrin formation and fibrinolysis is EC expression of annexin A2 (ANXA2) in a heterotetrameric complex with S100A10 [(ANXA2-S100A10) 2 ]. This complex is a well-recognized endothelial surface platform for the activation of plasminogen by tissue plasminogen activator. A noteworthy advance in this field came about when it was shown that the cAMP pathway is linked to the regulation of (ANXA2-S100A10) 2 in ECs. Objective: These findings prompted us to determine whether a druggable target, namely the exchange p rotein directly a ctivated by c AMP (EPAC) pathway, plays a role in vascular luminal fibrinolysis. Methods and Results: Taking advantage of our Epac1-null mouse model, we found that depletion of Epac1 results in fibrin deposition, fibrinolytic dysfunction, and decreased endothelial surface ANXA2 in mice, which are similar to phenomena discovered in ANXA2 -null and S100A10 -null mice. We observed upregulation of EPAC1 and downregulation of fibrin in endocardial tissues beneath atrial mural thrombi in humans. Of note, our thrombosis model revealed that dysfunction of fibrinolysis in EPAC1 -null mice can be ameliorated by recombinant ANXA2. Furthermore, we demonstrated that suppression of EPAC1 using a small-molecule inhibitor (ESI09) reduces the expression of ANXA2 in lipid rafts and impedes ANXA2 association with S100A10. Endothelial apical surface expression of both ANXA2 and S100A10 were markedly decreased in ESI09-treated ECs, which was corroborated by results from a nanoforce spectroscopy study. Moreover, inactivation of EPAC1 decreases tyrosine 23 phosphorylation of ANXA2 in the cell membrane compartment. Conclusions: Our data reveal a novel role for EPAC1 in vascular fibrinolysis, by showing that EPAC1 is responsible for the translocation of ANXA2 to the EC surface. This process promotes conversion of plasminogen to plasmin, thereby enhancing local fibrinolytic activity.