In vivo behavior of epoxy-crosslinked porcine heart valve cusps and walls

Abstract

Calcification limits the long-term durability of xenograft glutaraldehydecrosslinked heart valves. In this study, epoxy-crosslinked porcine aortic valve tissue was evaluated after subcutaneous implantation in weanling rats. Non-crosslinked valves and valves crosslinked with glutaraldehyde or carbodiimide functioned as control. Epoxy-crosslinked valves had somewhat lower shrinkage temperatures than the crosslinked controls, and within the series also some macroscopic and microscopic differences were obvious. After 8 weeks implantation, cusps from non-crosslinked valves were not retrieved. The matching walls were more degraded than the epoxy-and control-crosslinked walls. This was observed from the higher cellular ingrowth with fibroblasts, macrophages, and giant cells. Furthermore, noncrosslinked walls showed highest numbers of lymphocytes, which were most obvious in the capsules. Epoxy-and control-crosslinked cusps and walls induced lower reactions. Calcification, measured by von Kossa-staining and by Ca-analysis, was always observed. Crosslinked cusps calcified more than walls. Of all wall samples, the non-crosslinked walls showed the highest calcification. It is concluded that epoxy-crosslinked valve tissue induced a foreign body and calcification reaction similar to the two crosslinked controls. Therefore, epoxy-crosslinking does not represent a solution for the calcification problem of heart valve bioprostheses.

A facile chemical cross-linking approach toward the fabrication of a sustainable porous ulvan scaffold

“…21 In spite of being potential cross-linkers such as glutaraldehyde, formaldehyde, methyl glyoxal, bis-acrylamide, and epoxy-based compounds, their degradation products have been found to be cytotoxic. [22][23][24][25][26][27][28] Thus, developing a chemically benign yet a sustainable cross-linked product has become one of the top priorities for tissue engineering researchers. Generally, cations such as Ca+ 2 are the most favored ionic cross-linkers due to their tunability.…”

Treatment with bisphosphonates to mitigate calcification of elastin‐containing bioprosthetic materials

“…In 1987, Nojiri et al demonstrated the possibility of calcification suppression using epoxy compounds in place of GA for cross‐linking (Nojiri, Noishiki, & Koyanagi, 1987). However, later experimental studies found that epoxy compounds cannot block the calcification of the elastin‐rich aortic wall (Rapoport et al, 2007; Van Wachem et al, 2000).…”