Month: September 2022

Polymers (Basel). 2022 May 26;14(11):2156. doi: 10.3390/polym14112156.

ABSTRACT

(1) Background: Hemocompatibility is a critical challenge for tissue-derived biomaterial when directly contacting the bloodstream. In addition to surface modification with heparin, endothelialization of the grafted material is suggested to improve long-term clinical efficacy. This study aimed to evaluate the ability to endothelialize in vitro of heparinized bovine pericardial scaffolds. (2) Methods: bovine pericardial scaffolds were fabricated and heparinized using a layer-by-layer assembly technique. The heparinized scaffolds were characterized for heparin content, surface morphology, and blood compatibility. Liquid extraction of the samples was prepared for cytotoxicity testing on human endothelial cells. The in-vitro endothelialization was determined via human endothelial cell attachment and proliferation on the scaffold. (3) Results: The heparinized bovine pericardial scaffold exhibited a heparin coating within its microfiber network. The scaffold surface immobilized with heparin performed good anti-thrombosis and prevented platelet adherence. The proper cytotoxicity impact was observed for a freshly used heparinized sample. After 24 h washing in PBS 1X, the cell compatibility of the heparinized scaffolds was improved. In-vitro examination results exhibited human endothelial cell attachment and proliferation for 7 days of culture. (4) Conclusions: Our in-vitro analysis provided evidence for the scaffold’s ability to support endothelialization, which benefits long-term thromboresistance.

PMID:35683829 | PMC:PMC9182580 | DOI:10.3390/polym14112156

Sci Rep. 2022 Jun 20;12(1):10329. doi: 10.1038/s41598-022-14138-5.

ABSTRACT

Artificial biomaterials can significantly increase the rate of tissue regeneration. However, implantation of scaffolds leads not only to accelerated tissue healing but also to an immune response of the organism, which results in the degradation of the biomaterial. The synergy of the immune response and scaffold degradation processes largely determines the efficiency of tissue regeneration. Still, methods suitable for fast, accurate and non-invasive characterization of the degradation degree of biomaterial are highly demandable. Here we show the possibility of monitoring the degradation of decellularized bovine pericardium scaffolds under conditions mimicking the immune response and oxidation processes using multiphoton tomography combined with fluorescence lifetime imaging (MPT-FLIM). We found that the fluorescence lifetimes of genipin-induced cross-links in collagen and oxidation products of collagen are prominent markers of oxidative degradation of scaffolds. This was verified in model experiments, where the oxidation was induced with hypochlorous acid or by exposure to activated neutrophils. The fluorescence decay parameters also correlated with the changes of micromechanical properties of the scaffolds as assessed using atomic force microscopy (AFM). Our results suggest that FLIM can be used for quantitative assessments of the properties and degradation of the scaffolds essential for the wound healing processes in vivo.

PMID:35725581 | PMC:PMC9209456 | DOI:10.1038/s41598-022-14138-5

Sheng Wu Yi Xue Gong Cheng Xue Za Zhi. 2022 Jun 25;39(3):537-543. doi: 10.7507/1001-5515.202202044.

ABSTRACT

Currently, as the key raw material of artificial biological heart valve, bovine pericardium is mainly depend on import and has become a “bottleneck” challenge, greatly limiting the development of domestic biological heart valve. Therefore, the localization of bovine pericardium is extremely urgent. In this study, the pericardium of Sichuan yak was compared with that of Australian cattle in terms of fundamental properties and anti-calcification performance. The results demonstrated that the appearance and thickness of yak pericardium were more advantageous than the Australian one. Sichuan yak pericardium and Australian cattle pericardium had comparable performance in shrinkage temperature, mechanical test and anti-calcification test. This study preliminarily verifies the feasibility of substitution of Australian cattle pericardium by Sichuan yak pericardium and promotes the progression of bovine pericardium localization with data support.

PMID:35788523 | DOI:10.7507/1001-5515.202202044

ACS Appl Bio Mater. 2022 Aug 15;5(8):3883-3895. doi: 10.1021/acsabm.2c00423. Epub 2022 Jul 15.

ABSTRACT

Thrombogenicity, which is commonly encountered in artificial heart valves after replacement surgeries, causes valvular failure. Even life-long anticoagulant drug use may not be sufficient to prevent thrombogenicity. In this study, it was aimed to develop a heart valve construct with antithrombogenic properties and suitable mechanical strength by combining multiwalled carbon nanotubes within a decellularized bovine pericardium. In this context, the decellularization process was performed by using the combination of freeze-thawing and sodium dodecyl sulfate (SDS). Evaluation of decellularization efficiency was determined by histology (Hematoxylin and Eosin, DAPI and Masson’s Trichrome) and biochemical (DNA, sGAG and collagen) analyses. After the decellularization process of the bovine pericardium, composite pericardial tissues were prepared by incorporating -COOH-modified multiwalled carbon nanotubes (MWCNTs). Characterization of MWCNT incorporation was performed by ATR-FTIR, TGA, and mechanical analysis, while SEM and AFM were used for morphological evaluations. Thrombogenicity assessments were studied by platelet adhesion test, Calcein-AM staining, kinetic blood clotting, hemolysis, and cytotoxicity analyses. As a result of this study, the composite pericardial material revealed improved mechanical and thermal stability and hemocompatibility in comparison to decellularized pericardium, without toxicity. Approximately 100% success is achieved in preventing platelet adhesion. In addition, kinetic blood-coagulation analysis demonstrated a low rate and slow coagulation kinetics, while the hemolysis index was below the permissible limit for biomaterials.

PMID:35839464 | PMC:PMC9382671 | DOI:10.1021/acsabm.2c00423

J Cardiol Cases. 2022 Jan 3;25(5):297-299. doi: 10.1016/j.jccase.2021.11.010. eCollection 2022 May.

ABSTRACT

Cardiac calcified amorphous tumors are rare non-neoplastic intracavitary masses. Herein, we report a case of a 75-year-old woman who presented with dyspnea on exertion and multiple cerebral infarctions 3 months prior. Transthoracic echocardiography showed severe mitral regurgitation from the posterior mitral leaflet with valve perforation and severe mitral annular calcification. In addition, we observed a 13 mm mobile high echogenic mass, suggesting healed infective endocarditis. The mass was successfully resected, and the mitral valve was replaced with a bovine pericardial patch for the decalcified annulus. Histopathological examination confirmed cardiac calcified amorphous tumor; the postoperative course was uneventful. Mitral valve replacement and annulus patch repair effectively prevented postoperative recurrent systemic embolization. <Learning objective: Calcified amorphous tumor (CAT) is a risk factor for systemic embolism. Cardiac CAT destroying the mitral valve tissue and causing mitral valvular disease have been scarcely reported. We present a case of cardiac CAT with mitral valve perforation and suspected systemic embolization, treated successfully through mitral valve replacement and calcified lesion coverage by surgical resection and patch repair.>.

PMID:35582074 | PMC:PMC9091504 | DOI:10.1016/j.jccase.2021.11.010

Vasc Health Risk Manag. 2022 Apr 27;18:329-333. doi: 10.2147/VHRM.S363417. eCollection 2022.

ABSTRACT

BACKGROUND: Secondary aortoenteric fistula is a rare, highly morbid and often difficult to diagnose, cause of gastrointestinal bleeding. It is associated with prior aortic surgery or placement of a synthetic aortic graft. Our case features staged hybrid endovascular stent-grafting, graft excision, aortoplasty using a bovine pericardial patch, extra-anatomical bypass and complex bowel repair.

CASE REPORT: An 82-year-old man presented with gastrointestinal bleeding and Streptococcus Anginosus bacteraemia, with previous aorto-bi-iliac bypass surgery for left common iliac occlusive disease 15 years ago. Computed tomography angiography (CTA), gastroscopy, colonoscopy, capsule endoscopy and enteroscopy identified no bleeding source. Repeat CTA showed gas locules and stranding around the graft and the third part of the duodenum, concerning for fistulous communication. On the next day, a Zenith TX2 thoracic 28x80mm stent-graft was deployed into the infrarenal aorta. On laparotomy, a fistula was present between the Dacron graft and fourth part of the duodenum. The Dacron graft was excised, followed by aortic patching with bovine pericardium. A right-to-left femoral-femoral crossover graft was constructed. CT at one-month post-laparotomy showed no signs of perigraft endoleak and interval resolution of gas locules. He was transferred to a rehabilitation facility on the 34th post-operative day with a multidisciplinary follow-up arranged.

DISCUSSION: Aortoduodenal fistula is a challenging entity to diagnose and should be suspected in patients with GI bleeding and prior aortic surgery. Endovascular repair alone is a less invasive option but with higher re-infection and late failure rates. Liberal use of appropriate imaging modalities, a judicious repair strategy, long-term follow-up and multidisciplinary approach are critical for its management.

PMID:35510033 | PMC:PMC9058014 | DOI:10.2147/VHRM.S363417