Prospects in Lyophilization of Bovine Pericardium

Abstract

Almost 30 years after the introduction of heart valve prostheses patients worldwide are benefiting from the implant of these devices. Among the various types of heart valves, the ones made of treated bovine pericardium have become a frequently used replacement of the heart's native valve. Lyophilization, also known as freeze-drying, is an extremely useful technique for tissue storage for surgical applications. This article gives a brief overview on the current bovine pericardium lyophilization development, including the chemical modification to improve physical-chemical characteristics and the advanced technologies used to guarantee a high-quality product. It was shown that lyophilization process can be successfully applied as a method of bovine pericardium preservation and also as a technological tool to prepare new materials obtained by chemical modification of native tissues.

Effects of freeze‐drying of samples on metabolite levels in metabolome analyses

“…We did not compare the effects of different FD conditions, including temperature conditions of the cold trap, and these conditions may also influence the outcome. Previously, liposomes and bacterium stability were reported to be affected by different FD conditions 1, 5–8. Recently, a new method, vacuum microwave drying, has been tested for drying foods 11, 14, 18.…”

“…Once samples are freeze‐dried, they are biologically and chemically more stable than fresh samples, making handling for shipping and storage easier 1, 2. Therefore, FD is used in a variety of processes, such as preparation of pharmaceuticals 2–4, long‐term storage of liposomes as drug delivery systems 5, production of starter cultures of lactic acid bacterium 6, 7, tissue storage for surgical applications 8, and manufacture of dry foods 9, 10. Many reports showed that the levels of bioactive compounds, such as polyphenols in freeze‐dried fruits and crops, were higher than in fresh fruit or in fruit that had been dried by conventional methods 10–14.…”

“…In addition, FD causes changes in the relative concentrations of volatile compounds and polyphenols 4, destabilization of liposome structure 5, 15, reductions in cell viability 7, 16, protein degradation 2, 17, and loss of flavor or taste 11, 18. Therefore, the optimal conditions of FD have been examined for individual freeze‐dried products 2, 5–8. In addition, various additives such as cryoprotectants or excipients are often used in the manufacturing of freeze‐dried products 5, 15–17.…”

The effects of anticalcification treatments and hydration on the molecular dynamics of bovine pericardium collagen as revealed by 13C solid‐state NMR

“…GL‐treated BP has been used extensively to construct heart valve bioprostheses, patches, and to shape conduits. GL stabilizes the collagen structure, prevents tissue digestion by enzymes or bacteria, and reduces the antigenicity of the material 5…”

Freeze-drying microscopy in mathematical modeling of a biomaterial freeze-drying

“…When applied to biological human or animal tissues for regenerative medicine or tissue engineering purposes, the freeze-drying process allows fundamental properties of these materials to be preserved, making future manipulation and storage much easier (Aimoli et al, 2007;Borgognoni et al, 2010;Leirner, Tattini Jr, Pitombo, 2009). Freeze-drying is a very lengthy process C. F. Borgognoni, J. S. Bevilacqua, R. N. M. Pitombo 204 when compared to other methods of drying because of the low drying rate and operation under reduced pressure.…”