Kinetic study of collagen fixation with polyepoxy fixatives

Abstract

A new biomaterial has been developed by fixing native collagen with a polyepoxy compound (PC) fixative. In this study, bovine internal thoracic arteries were fixed with PC under various conditions to help understand the kinetics of the collagen-PC reactions and optimize the fixation process. At predetermined time intervals, small samples were cut from the arteries to determine the quantities of the remaining unreacted amino acids in the collagen. Temperature, concentration, and solution pH were among the key parameters studied. The overall fixation rate was found to be reaction-rate controlled, as the rate of fixation was relatively slow compared with the rate of diffusion of PC. As might be expected, the reaction rate was favored by a higher temperature, concentration, and solution pH. A kinetic model, with a 2.5th reaction order with respect to the reactive functional groups of collagen and a first order with respect to PC, was developed that gave a good fit to the experimental data. Based on this model, the degree of fixation, X, as a function of time, t, is given by (1 - X)-1.5 = 1 + Kt, where K is a constant related to the initial concentrations and the reaction rate constant.

The role of collagen in the declining mechanical properties of aging human cortical bone

“…19 The technique has proved valuable in assessing the efficiency and density of artificially induced intermolecular crosslinks, produced by various chemical tanning agents, on a number of tissues. [20][21][22][23] The shrinkage temperature of cortical bone collagen has been shown to decline with age in rats 11 and in humans, healthy or otherwise. 4 A concomitant decrease in the biochemical stability of a tissue 4 implies that bone collagen becomes less stable with age.…”

Chitosan/polyethylene glycol-alginate microcapsules for oral delivery of hirudin

“…17 Further, it has been observed that the PEGs can abrogate the immunogenicity of proteins and are capable of preserving their biological properties. 18,19 PEGs are used for improving the biocompatibility of polymers.…”

Characterization and implantation of a novel foamy type of collagen into SD rats to regenerate tissue by slowing down the collagen degradation rate

“…Traditionally, crosslinking reagents have been used to strengthen the mechanical properties of porous collagen and to slow down its degradation rate. However, most crosslinking reagents are cytotoxic and thus cannot be used for tissue regeneration [19][20][21][22][23][24][25][26]. Hence, the development of a novel type of collagen that can address the previous limitation is important.…”

“…Traditionally, crosslinking reagents such as glutaraldehyde, carbodiimide, and epoxy compounds, among others, have been used to slow down the degradation rate of porous collagen. However, most crosslinking reagents are cytotoxic and are not suitable for tissue regeneration [19][20][21][22][23][24][25][26].…”