Wyniki wyszukiwania - BazTech

Ograniczanie wyników

Znaleziono wyników: 2

Liczba wyników na stronie

Wyniki wyszukiwania

Wyszukiwano:
w słowach kluczowych: bioprostheses

Sortuj według:

Ogranicz wyniki do:

Radioisotopic investigation of crosslinking density in bovine pericardium used as a biomaterial

Turek A., Cwalina B., Kobielarz M.

Nukleonika

2013

Vol. 58, No. 4

511--517

Stabilized bovine pericardium (BP) belongs to tissues routinely applied in production of heart valves. Commercial products are manufactured from tissues crosslinked by glutaraldehyde (GA). Dye-mediated photooxidation was also proposed as an alternative method, which allows for the elimination of clinical failures of GA-treated tissues. The aim of the study was to investigate the density of BP stabilized by GA and the methylene blue-mediated photooxidation, as compared with a native tissue. Crosslinking density was evaluated based on their ability to accumulate radioactive cobalt ions (60Co2+) and the permeability to these ions. Radioactivity was examined using a γ-spectrophotometer (Packard). The results showed the changes in the crosslinking density between the native tissues and photooxidized or GA-crosslinked tissues. Significant decreases in radioactivity were detected only in the thinnest tissues after photooxidation and in filtrates penetrating the same samples. Photooxidized pericardium of a larger thickness did not reveal any significant changes. Weight-dependence for the permeability was observed in the case of filtrates penetrating the GA-treated tissues. However, 60Co2+-accumulation in these samples remained at the same level. Photooxidation may lead to obtaining biomaterials with advantageous properties, i.e. a decreased calcium-binding capacity. Photooxidation efficiencies were dependent both on compactness and thickness of tissues and on process duration. It should be emphasized that the tissues’ structure after photooxidation was characterized by lower density. This may point to the presence of crosslinks of a smaller compactness in comparison with GA treatment. It has been shown that the factor indeed influencing the result of crosslinking is tissue thickness.

Wpływ fotooksydacji w obecności błękitu metylenowego na właściwości mechaniczne osierdzia świni

Turek A., Kobielarz M., Cwalina B., Będziński R.

Engineering of Biomaterials

2010

Vol. 13, no. 96-98

99--103

Eliminacja najczęstszych wad stabilizacji tkanek zwierzęcych bogatych w kolagen jest przyczyną poszukiwań nowych metod ich przetwarzania. Celem przedstawionych badań było określenie właściwości mechanicznych osierdzia włóknistego świni domowej po fotostabilizacji przez 8 h i 24 h w obecności światła białego (50 W) i 0,05% roztworu błękitu metylenowego. Badania przeprowadzono z wykorzystaniem testu jednoosiowego rozciągania tkanek ze stałą prędkością 0,3 mm/s, w warunkach pełnego ich uwodnienia w 0,9% roztworze chlorku sodu. Przeprowadzone badania ujawniły istotne zmniejszenie siły zrywającej w przypadku tkanek poddanych fotooksydacji, przy zachowaniu ich sztywności i wartości wydłużenia. W prezentowanych badaniach wykazano, iż fotostabilizacja wpływa na właściwości mechaniczne osierdzia.

The elimination of the most frequent drawbacks resulting from stabilization of animal collagen-rich tissues is the reason for seeking novel methods of their processing. The aim of this work was the determination of mechanical properties of fibrous porcine pericardium after 8 h and 24 h photostabilization in the presence of visible light (50 W) and 0.05% solution of methylene blue. Uniaxial tensile test of tissue specimens was performed with constant rate at 0.3 mm/s, in the condition of full-hydration in 0.9% sodium chloride solution. The studies showed significant decrease of failure force in the case of photooxidized tissues, with preservation of the stiffness and values of maximum extension. The studies have shown that photostabilization influences the mechanical properties of pericardium.