Use of sucrose to diminish pore formation in freeze-dried heart valves

• Published in: Scientific reports 2018-08, Vol.8 (1), p.12982-12, Article 12982
• Main Authors: Vásquez-Rivera, Andrés, Oldenhof, Harriëtte, Dipresa, Daniele, Goecke, Tobias, Kouvaka, Artemis, Will, Fabian, Haverich, Axel, Korossis, Sotirios, Hilfiker, Andres, Wolkers, Willem F.
• Format: Article
• Language: English
• Subjects: 13/107; 14/63; 14/69; 631/61/490; 692/4019/592/2725; Biomechanics; Calorimetry; Collagen; Differential scanning calorimetry; Elastin; Fourier transforms; Freeze drying; Heart; Humanities and Social Sciences; Infrared spectroscopy; multidisciplinary; Pores; Porosity; Rehydration; Science; Science (multidisciplinary); Sucrose
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/s41598-018-31388-4

Freeze-dried storage of decellularized heart valves provides easy storage and transport for clinical use. Freeze-drying without protectants, however, results in a disrupted histoarchitecture after rehydration. In this study, heart valves were incubated in solutions of various sucrose concentrations and subsequently freeze-dried. Porosity of rehydrated valves was determined from histological images. In the absence of sucrose, freeze-dried valves were shown to have pores after rehydration in the cusp, artery and muscle sections. Use of sucrose reduced pore formation in a dose-dependent manner, and pretreatment of the valves in a 40% (w/v) sucrose solution prior to freeze-drying was found to be sufficient to completely diminish pore formation. The presence of pores in freeze-dried valves was found to coincide with altered biomechanical characteristics, whereas biomechanical parameters of valves freeze-dried with enough sucrose were not significantly different from those of valves not exposed to freeze-drying. Multiphoton imaging, Fourier transform infrared spectroscopy, and differential scanning calorimetry studies revealed that matrix proteins (i.e. collagen and elastin) were not affected by freeze-drying.