Crosslinking porcine aortic valve by radical polymerization for the preparation of BHVs with improved cytocompatibility, mild immune response, and reduced calcification

Allograft valves harvesting and preservation technique for enhanced performance

Allograft valves offer significant advantages in valve replacement; however, their limited availability from cadaveric or brain-dead donors presents a considerable challenge. This study aims to share our experience in harvesting and preserving Allograft valves from heart transplant recipients, addressing this shortage and streamlining the process. Allograft valves were harvested from patients who underwent heart transplants at our center from October 2007 to October 2022. After sampling of the allograft for quality control, allograft valves were cryopreserved and thawed before implantation. Allograft valves were used in 60 patients who had pulmonary valve replacement (PVR) in or after repaired Tetralogy of Fallot (TOF). Patient data were collected and statistically analyzed. The age of donors was 39.0 ± 186.0 years while the median age of recipients was 5.1 years (interquartile range, 1.5-12.1). After a median follow-up of 2.6 years (interquartile range, 1.0-6.9), the freedom from all-cause mortality was 94.0%, 89.5%, and 89.5% at 5, 10, and 15 years, respectively. Adverse clinical outcomes, occurred in 24 patients (40.0%), while freedom is 64.9%, 53.4%, and 31.7% for 5, 10, and 15 years. Allograft valves bicuspidized (odds ratio, 75.085; 95% confidence interval, 10.100-558.202, P < 0.001) and early postoperative regurgitation (odds ratio, 9.946; 95% confidence interval, 1.034-95.706, P = 0.047) were considered independent risk factors for adverse clinical outcomes. Our study presents our approach to harvesting and preserving allograft valves from heart transplant recipients, demonstrating favorable short to mid-term outcomes when utilized in allograft valves for patients with or after repaired TOF. We recommend vigilant monitoring of early postoperative regurgitation, as it may signal a poor prognosis, and we strongly advise against bicuspidized the implanted allograft valves.

Butterfly-Inspired Multiple Cross-Linked Dopamine-Metal-Phenol Bioprosthetic Valves with Enhanced Endothelialization and Anticalcification

Valve replacement is the most effective means of treating heart valve diseases, and transcatheter heart valve replacement (THVR) is the hottest field at present. However, the durability of the commercial bioprosthetic valves has always been the limiting factor restricting the development of interventional valve technology. The chronic inflammatory reaction, calcification, and difficulty in endothelialization after the implantation of a glutaraldehyde cross-linked porcine aortic valve or bovine pericardium often led to valve degeneration. Improving the biocompatibility of valve materials and inducing endothelialization to promote in situ regeneration can extend the service life of valve materials. Herein, inspired by the hardening process of butterfly wings, this study proposed a dopamine-metal-phenol strategy to modify decellularized porcine pericardium (DPP). This is a strategy to make dopamine (DA) coordinate trivalent metal chromium ions (Cr(III)) with antiplatelets (PLTs) and anti-inflammatory properties, and then cross-link it with tea polyphenols (TP) to generate a valve scaffold that is mechanically comparable to glutaraldehyde-cross-linked scaffolds but avoids the cytotoxicity of aldehyde and presents better biocompatibility, hemocompatibility, anticalcification, and anti-inflammatory response properties.

Recent Advances in the Modification and Improvement of Bioprosthetic Heart Valves

Valvular heart disease (VHD) has become a burden and a growing public health problem in humans, causing significant morbidity and mortality worldwide. An increasing number of patients with severe VHD need to undergo heart valve replacement surgery, and artificial heart valves are in high demand. However, allogeneic valves from donors are lacking and cannot meet clinical practice needs. A mechanical heart valve can activate the coagulation pathway after contact with blood after implantation in the cardiovascular system, leading to thrombosis. Therefore, bioprosthetic heart valves (BHVs) are still a promising way to solve this problem. However, there are still challenges in the use of BHVs. For example, their longevity is still unsatisfactory due to the defects, such as thrombosis, structural valve degeneration, calcification, insufficient re-endothelialization, and the inflammatory response. Therefore, strategies and methods are needed to effectively improve the biocompatibility and longevity of BHVs. This review describes the recent research advances in BHVs and strategies to improve their biocompatibility and longevity.

Recent progress in functional modification and crosslinking of bioprosthetic heart valves

Valvular heart disease (VHD), clinically manifested as stenosis and regurgitation of native heart valve, is one of the most prevalent cardiovascular diseases with high mortality. Heart valve replacement surgery has been recognized as golden standard for the treatment of VHD. Owing to the clinical application of transcatheter heart valve replacement technic and the excellent hemodynamic performance of bioprosthetic heart valves (BHVs), implantation of BHVs has been increasing over recent years and gradually became the preferred choice for the treatment of VHD. However, BHVs might fail within 10-15 years due to structural valvular degeneration (SVD), which was greatly associated with drawbacks of glutaraldehyde crosslinked BHVs, including cytotoxicity, calcification, component degradation, mechanical failure, thrombosis and immune response. To prolong the service life of BHVs, much effort has been devoted to overcoming the drawbacks of BHVs and reducing the risk of SVD. In this review, we summarized and analyzed the research and progress on: (i) modification strategies based on glutaraldehyde crosslinked BHVs and (ii) nonglutaraldehyde crosslinking strategies for BHVs.

Is cell regeneration and infiltration a double edged sword for porcine aortic valve deterioration? A large cohort of histopathological analysis

BACKGROUND AND OBJECTIVE

Bioprostheses are the most common prostheses used for valve replacement in the Western medicine. The major flaw of bioprostheses is the occurrence of structural valve deterioration (SVD). This study aimed to assess the pathological features of porcine aortic valve (PAV)-SVD based on histomorphological and immunopathological characteristics of a large cohort of patients.

METHODS

Histopathological data of 109 cases with resected PAV were collected. The type and amount of infiltrated cells were evaluated in the different types of bioprosthetic SVD by immunohistochemical staining.

RESULTS

The most common cause of SVD was calcification, leaflet tear, and dehiscence (23.9%, 19.3%, and 18.3%, respectively). Immunohistochemical staining demonstrated that macrophages were infiltrated in the calcified, lacerated and dehiscence PAV, in which both M1 and M2 macrophages were existed in the calcified PAV. Importantly, the higher content of M1 macrophages and less content of M2 macrophages were found in the lacerated and dehiscence PAV, and MMP-1 expression was mainly found in the lacerated PAV. The endothelialization rate of leaflet dehiscence was higher than that of calcified and lacerated leaflets. A large number of CD31+/CD11b+ cells was aggregated in the spongy layer in the lacerated and dehiscence PAV.

CONCLUSION

Cell regeneration and infiltration is a double edged sword for the PAV deterioration. Macrophage infiltration is involved in the different types of SVD, while only MMP-1 expression is involved in lacerated leaflets. The macrophage subtype of circulating angiogenic cells in dehiscence and tear PAV could be identified, which could reserve macrophages in the PAV-SVD.

The Curative Effect of Shuangshen Decoction Combined with Immunological Preparations in the Treatment of Pediatric Nephrotic Syndrome and Its Influence on the Rate of Complicated Infection and Recurrence

BACKGROUND

To explore the curative effect of Shuangshen Decoction combined with immunological preparations in the treatment of pediatric nephrotic syndrome and its influence on concurrent infection and recurrence rate.

METHODS

Ninety children with nephrotic syndrome were divided into the routine group and the combined group. The routine group received conventional treatment and immune agents, and the combined group was treated with Shuangshen Decoction on the basis of the routine group. The clinical indexes of the two groups were analyzed and followed up. The infection rate and recurrence rate were calculated.

RESULTS

The TCM syndrome scores in the combined group were significantly lower than those in the routine group. The total effective rate of the combined group was significantly higher than that of the routine group. The recurrence rate and infection rate of the combined group were significantly lower than those of the routine group. The incidence of adverse reactions in the combined group was significantly lower than that in the routine group.

CONCLUSION

Shuangshen Decoction combined with immune preparations is effective in treating pediatric nephrotic syndrome and can reduce the incidence of adverse reactions, infection rate, and recurrence rate.