Category: General

Sci Adv. 2025 Jun 20;11(25):eadw0808. doi: 10.1126/sciadv.adw0808. Epub 2025 Jun 18.

ABSTRACT

Bovine pericardium is the tissue of choice for replacing heart valves of human patients in minimally invasive surgery. The tissue has an extraordinarily high toughness of ~100 kilojoules per square meter. Here, we investigate the origin of the toughness through mechanical tests and microscopic observations. In the tissue, crimped, long, strong collagen fibers are embedded in a soft matrix. As a crack grows in the matrix, the fibers decrimp, reorient, slip, and bridge the crack. These microscopic processes enable the fibers to transmit high tension over a long distance. Using two types of experiments, we measure the bridging traction as a function of crack separation, σ(δ). The peak traction is σ₀ ~ 60 megapascals. The maximum separation is δ₀ ~ 6 millimeters, two to four orders of magnitude higher than that of hard tissues. Both the high traction and large separation of the bovine pericardium contribute to its high toughness.

PMID:40532007 | PMC:PMC12175909 | DOI:10.1126/sciadv.adw0808

Clin Case Rep. 2025 Jul 27;13(8):e70655. doi: 10.1002/ccr3.70655. eCollection 2025 Aug.

ABSTRACT

This case report highlights an innovative surgical approach in orthotopic heart transplantation (OHT) for a patient with the largest recorded giant left atrium, measuring a biplanar volume of 1906 mL. The patient, a 63-year-old man with severe heart failure and a history of mitral and aortic valve replacements, presented with atrial fibrillation, moderate systolic dysfunction, and severe cardiomegaly. Despite optimized medical therapy, his condition warranted heart transplantation. The procedure involved a novel surgical technique utilizing Teflon reinforcement and a bovine pericardial patch to reconstruct the significantly enlarged left atrium. Postoperative outcomes were favorable, with no rejection episodes and resolution of pulmonary symptoms. This report underscores the challenges of atrial size mismatch in OHT and the necessity for tailored surgical strategies to address extreme anatomical variations. The successful outcome exemplifies the potential of customized approaches in complex heart transplant cases.

PMID:40735707 | PMC:PMC12301168 | DOI:10.1002/ccr3.70655

Polymers (Basel). 2025 Jun 5;17(11):1576. doi: 10.3390/polym17111576.

ABSTRACT

The aim of this study was to evaluate the effect of suture material made of polyester (PET), polypropylene (PP), and polytetrafluoroethylene (PTFE) on the calcification of a bovine pericardium (BP) consisting of collagen biopolymer preserved with an epoxy compound. Non-porous film made of the synthetic reinforced polymer REPEREN^® was chosen as a control material. Samples of the material (sutured or non-sutured with each of the three types of surgical sutures) were implanted subcutaneously in 45 young rats for 30, 60, and 90 days. The calcium content of the explants was quantified using atomic absorption spectrometry, a histological examination was performed using hematoxylin and eosin and von Kossa staining, and the structure of the calcium phosphate deposits was studied using scanning electron microscopy (SEM) and energy dispersive spectrometry (EDS) with color field mapping. The results demonstrated the absence of calcification in the non-sutured BP and in all the REPEREN^® groups. In the sutured BP samples, a dynamic increase in the Ca content and the Ca/P ratio to 1.67-1.7 (crystalline hydroxyapatite) was observed by the 90th day. The minimum Ca content among the sutured BP groups was detected in samples where the PET thread was used. The cellular reaction to BP was significantly more pronounced than the reaction to REPEREN^® throughout the entire observation period; collagen homogenization was noted near the sutures. It can be concluded that all the studied suture materials provoke BP calcification. PET has the minimal negative effect.

PMID:40508818 | PMC:PMC12157850 | DOI:10.3390/polym17111576