UNASSIGNED: The treatment of infectious aortic disease is still challenging with open surgical debridement and reconstruction using biological, preferably autologous material, being the treatment of choice. However, these procedures are associated with high morbidity and mortality. Endovascular therapy is often considered a bridging method only, since the biologically inactive fabric of the covered stent grafts usually cannot be treated sufficiently with anti-infective agents in the event of a (obligate) consecutive secondary graft infection. This study aims to prove the feasibility of a physician-made pericardium stent graft ex-vivo.
UNASSIGNED: A state-of-the-art TEVAR was modified by separating the fabric from the z-stents and suturing a hand-sewn bovine pericardium tube to the bare metal. Feasibility of preparation, re-sheathing, and delivery is demonstrated in an ex-vivo model.
UNASSIGNED: This first xenogeneic stent graft could be manufactured and deployed successfully. In the future this may provide a bridging alternative for high-risk patients with infected native aortic aneurysm or aortic fistulas, eventually followed by surgical or thoracoscopic/laparoscopic debridement. Further studies on simulators or animal models are needed to test the technique and investigate its long-term durability. Additionally, this study prompts reflection on whether materials currently used should be further developed to prevent graft infections.

Defects in the dura matter can be caused by head injury, and many cases require neurosurgeons to use artificial dura matter. Bovine pericardium is an option due to its abundant availability, adjustable size and characteristics, and because it has more collagen than porcine or equine pericardia. Nevertheless, the drawback of bovine pericardium is that it has a higher inflammatory effect than other synthetic dura matters. Chitosan has been shown to have a strong anti-inflammatory effect and has good tensile strength; thus, the idea was formulated to use chitosan as a coating for bovine pericardium. This study used decellularized bovine pericardial membranes with 0.5% sodium dodecyl sulphate and coatings containing chitosan at concentrations of 0.25%, 0.5%, 0.75%, and 1%. An FTIR test showed the presence of a C=N functional group as a bovine pericardium-chitosan bond. Morphological tests of the 0.25% and 0.5% chitosan concentrations showed standard pore sizes. The highest tensile strength percentage was shown by the membrane with a chitosan concentration of 1%. The highest degradation rate of the membrane was observed on the 7th and 14th days for 0.75% and 1% concentrations, and the lowest swelling ratio was observed for the 0.25% concentration. The highest level of cell viability was found for 0.75% chitosan. The bovine pericardium membrane with a 0.75% concentration chitosan coating was considered the optimal sample for use as artificial dura matter.

Leaflet damage has been documented to occur while deploying a transcatheter aortic valve (TAV) due to mechanical loads during the crimping procedures. In this study, the impact of compressive stress on folded leaflets was measured to investigate the mechanism of traumatic leaflet tissue damage. Numerical simulation of TAV crimping procedure was adapted to calculate stress magnitude and distribution of leaflets. A 20 mm balloon expanding short stent TAV with 0.25 mm thickness leaflets was used in the simulation. Then the calculated stresses were applied on leaflet material (bovine pericardium) samples by loading experiments. Mechanical properties evaluation combined with histological and microscopy observation were used to investigate the tissue damage. The elastic modulus and the tensile strength of the tissue began to decrease significantly at 2 MPa stress and 2.5 MPa stress, respectively. No significant differences were observed at 0-1.5 MPa stress. When the TAV was crimped to 14 Fr and 12 Fr, the 2 MPa greater areas on leaflets increased from 18.17% to 76.96%. 2 MPa compressive stress might be the threshold value for leaflet damage. The TAV crimping size should be paid attention to avoid the compressive stress higher than 2 MPa.

UNASSIGNED: Bovine pericardium can be used for cardiovascular repair surgeries, but challenges involving biocompatibility and durability remain. This study aimed to carry out pre-clinical testing of aortic valve replacement using an aortic valve prosthesis made of bovine pericardium modified with glutaraldehyde (GA) and 2,3-butanediol (BD).
UNASSIGNED: The mechanical, plasma protein adsorption, platelet adhesion, collagenase digestion, and ninhydrin properties of the material (control vs. GA vs. GA + BD) were tested. All 3 tissues were implanted in rats and observed after 8 weeks under microscopy with alizarin red staining for calcification. Aortic valves made from the fully-treated material were implanted in sheep. A commercial bioprosthesis was used as control. Effectiveness and safety indicators were observed at 180 days after implantation.
UNASSIGNED: Compared with the control group, the GA + BD material showed higher elongation at breaking and tensile load (both P<0.05), lower plasma protein adsorption, lower platelet adhesion, lower collagenase digestion, lower ninhydrin value, and higher cross-linking (all P<0.05). After implantation in rat models, the GA + BD material showed little or no dissolution; there was no obvious calcification; and it was surrounded by a small amount of fibrosis, with peripheral capillary proliferation. After implantation in sheep models, the aortic valve leaflets of the experimental animals freely opened and closed, their surface was smooth, and no abnormal echo was observed. The echocardiographic results and hemodynamic were comparable between the two groups. All safety parameters were normal.
UNASSIGNED: Modification of bovine pericardium with GA and BD results in a biomaterial with favorable properties for use as an aortic valve prosthesis.

Bioprosthetic heart valves made from bovine pericardium (BP) and porcine pericardium (PP) preserved with glutaraldehyde (GA) are commonly used in valve surgeries but prone to calcification in many patients. In this study, we compared BP and PP preserved with GA, ethylene glycol diglycidyl ether (DE), and 1,2,3,4,6-penta-O-{1-[2-(glycidyloxy)ethoxy]ethyl}-d-glucopyranose (PE). We studied the stabilities of DE and PE in preservation media along with the amino acid (AA) compositions, Fourier-transform infrared spectra, mechanical properties, surface morphologies, thermal stability, calcification, and the cytocompatibility of BP and PP treated with 0.625% GA, 5% DE, 2% PE, and alternating 5% DE and 2% PE for 3 + 11 d and 10 + 10 d, respectively. Both epoxides were stable in the water-buffer solutions (pH 7.4). DE provided high linkage densities in BP and PP owing to reactions with Hyl, Lys, His, Arg, Ser, and Tyr. PE reacted weakly with these AAs but strongly with Met. High cross-linking density obtained using the 10 d + 10 d method provided satisfactory thermal stability of biomaterials. The epoxy preservations improved cytocompatibility and resistance to calcification. PE enhanced the stress/strain properties of the xenogeneic pericardia, perhaps by forming nanostructures that were clearly visualised in BP using scanning electron microscopy. The DE + PE combination, in an alternating cross-linking manner, thus constitutes a promising option for developing bioprosthetic pericardia.

Bovine pericardium has been proposed as an available material for tissue engineering and bioprosthetic reconstruction. In this study, bovine pericardium was fabricated into a scaffold for culturing and chondrogenic differentiation of human adipose-derived stem cells (hADSCs). Bovine pericardium was treated in 10 mM Tris-HCl and 0.15% SDS, followed by crosslinking in 0.1% glutaraldehyde. Treated bovine pericardium (tBP) was characterized as a slight yellowish thin membrane with enhanced tensile strength and strain property. The membrane maintained stability under enzymatic conditions for up to 16 days of incubation. The results confirmed tBP as a cell-friendly scaffold for hADSCs due to low cytotoxicity and its ability to support an appropriate attachment and proliferation of hADSCs. Moreover, there was an accumulation of the extracellular matrix proteoglycan in tBP seeded with hADSCs after 7 and 14 days of chondrogenic induction. COMP as a specific marker of chondrogenesis was detected after 7 days, whereas type X-a1 collagen (Col10a1) expression was stable up to day 14. However, minor expression of aggrecan was found. Taken together, these results indicate that tBP is a potential scaffold for hADSCs for cartilage tissue engineering.Key words: Bovine pericardium, scaffold, adipose-derived stem cells, chondrogenic differentiation, cartilage regeneration, augmentation rhinoplasty.

Decellularized bovine pericardium (DBP)-based biomeshes are the gold standard in reconstructive surgery. In order to prolong their stability after the transplantation, various chemical cross-linking strategies are employed. However, structural and functional properties of the biomeshes differ in dependence on the cross-linker used. Here, we performed a bottom-up study of structural and functional alterations of DBP-based biomeshes following cross-linking with hexamethylene diisocyanate (HMDC), ethylene glycol diglycidyl ether (EGDE), 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide (EDC) and genipin. The in vitro cytotoxicity tests supported their clinical applicability. Their structural differences (eg roughness, fibre thickness, pore morphology) were evaluated using the two-photon confocal laser scanning, atomic force, scanning electron and polarized light microscopies. HMDC and EDC samples appeared to be the roughest. Complex mechanical trials indicated the tendency to reduced Young\'s Modulus and mechanical anisotropy values of DBP upon cross-linking. The lowest mechanical anisotropy was found in EDC and genipin sample groups. In vitro collagenase susceptibility was the highest for EDC samples and the lowest for EGDE samples. The comparative analysis of the results allowed us to recognize the strengths and weaknesses of each cross-linker in relation to a particular clinical application.

BACKGROUND: Prosthetic heart valves designed to be implanted percutaneously must be loaded within delivery catheters whose diameter can be as low as 18 F (6 mm). This mandatory crimping of the devices may result in deleterious damages to the tissues used for valve manufacturing. As bovine and porcine pericardial tissue are currently given preference because of their excellent availability and traceability, a preliminary comparative study was undertaken to highlight their potential advantages.
METHODS: Bovine and pericardium patches were compared morphologically (light microscopy, scanning electron microscopy and transmission electron microscopy). The acute thrombogenicity of both materials was measured in term of platelet uptake and observed by scanning electron microscopy, porcine intact and injured arteries being used as controls. The pericardium specimens were also subjected to uniaxial tensile tests to compare their respective mechanical characteristics.
RESULTS: Both pericardiums showed a layered architecture of collagen bundles presenting some interstitial cells. They displayed wavy crimps typical of an unloaded collagenous tissue. The collagen bundles were not bound together and the fibrils were parallel with characteristic periodicity patterns of cross striations. The mesothelial cells found in vivo on the serous surface were no longer present due to tissue processing, but the adjacent structure was far more compacted when compared to the fibrous side. The fibrinocollagenous surfaces were found to be more thrombogenic for both bovine and porcine tissues and the serous side of the porcine pericardium retained more platelets when compared to the bovine samples, making the acute thrombogenicity more important in the porcine pericardium.
CONCLUSIONS: Both bovine and porcine pericardium used in cardiovascular implantology can be selected to manufacture percutaneous heart valves. The selection of one pericardium preferably to the other should deserve additional testing regarding the innocuousness of crimping when loaded in delivery catheters and the long-term durability after percutaneous deployment.