Cytotoxicity of glutaraldehyde crosslinked collagen/poly(vinyl alcohol) films is by the mechanism of apoptosis

Abstract

Collagen has been investigated as a potential natural biomaterial, because of its occurrence in the extracellular matrix. Collagen requires crosslinking in this context, by reagents that are often cytotoxic. Glutaraldehyde is one such agent that is potentially cytotoxic. The aim of this study was to determine the cause of poor cell attachment and growth on collagen/poly(vinyl alcohol) bioartificial composite films, when crosslinked with glutaraldehyde. Dehydrothermal crosslinking was used as a comparison. Human osteoblasts were observed to undergo apoptosis on glutaraldehyde crosslinked films dependent on concentration of collagen present. Higher collagen content resulted in higher levels of apoptosis with poor cell attachment and spreading of remaining cells. Post-treatment of films with 8% L-glutamic acid prevented the apoptotic response of osteoblasts and allowed attachment and spreading. The addition of 100 nM insulin-like growth factor-1 to the culture medium also prevented apoptosis. Glutaraldehyde toxicity of crosslinked collagen has been demonstrated in this study, the mechanism of which is apoptosis. This study indicates that poor biocompatibility and induction of apoptosis on collagen/poly(vinyl alcohol) films crosslinked by glutaraldehyde are attributed to glutaraldehyde components on the surface of the films (not residual glutaraldehyde), whose effects can be quenched by glutamic acid, and prevented by insulin-like growth factor-1.

Cytocompatibility studies of mouse pancreatic islets on gelatin - PVP semi IPN scaffolds in vitro: Potential implication towards pancreatic tissue engineering

“…The unstable GTA polymers that may have been retained during the cross linking procedure may have implicated in the toxicity of cells. 31 Hence we presume that the concentration of GTA used in this study (1% GTA) may not be suitable for islet cell culture. It is also possible that trace quantities of GTA are released on degradation of GPG while immersed in media, thereby having implications on the viability of islet cells.…”

Reactionary and reparative dentin formation after pulp capping: Hydrogel vs. Dycal

“…Bars: 100 μm requires cross-linking by reagents such as GA, potentially cytotoxic. We assume that apoptosis and/or nemosis may be involved in the mechanism of GA toxicity of crosslinked collagen (Gough et al 2002). Metalloprotease degradation of Hydrogel contributes to the releases of GA, also known to be a cell fixative.…”

Glutaraldehyde cross-linking of amniotic membranes affects their nanofibrous structures and limbal epithelial cell culture characteristics

“…GTA is known to be very reactive. 27 At the initial stage, the cross-linking reaction may proceed too quickly to reduce the mobility of protein molecules and to form surface barriers to cross-linker permeation. Nevertheless, after the GTA diffusion into the AM matrix with time, these effects are weakened because of continued generation of cross-links by collision between the collagen and cross-linker molecules.…”