Eliminating glutaraldehyde from crosslinked collagen films using supercritical CO₂

Abstract

Collagen has received considerable attention as a biomaterial for tissue engineering because of its low immunogenicity, controllable biodegradation, and ability to influence cell growth and proliferation. Frequently, collagen scaffolds require crosslinking to improve mechanical strength, requiring agents like glutaraldehyde that have high residual cytotoxicity. A novel method for extracting residual glutaraldehyde from crosslinked collagen films with supercritical carbon dioxide (CO 2 ) is presented. CO 2 is a nontoxic, nonflammable substance that is relatively inert and can be used to process biomaterials at mild pressures and physiologic temperatures. In this work, it was first determined that type I collagen is chemically compatible with both liquid and supercritical CO 2 . Treated collagen showed minimal changes in physicochemical properties as determined by differential scanning calorimetry, gel electrophoresis, and circular dichroism. CO 2 was subsequently used to extract residual glutaraldehyde from crosslinked collagen films. Glutaraldehyde concentration was reduced by over 95%, from over 20 ppm before treatment to about 1 ppm, in only 1 h. CO 2 treatment caused negligible alteration of thermal stability but did significantly increase film stiffness and tensile strength. However, these changes were minor compared to heat-based removal of glutaraldehyde.

Bioprinting of Collagen: Considerations, Potentials, and Applications

“…"Chemical" crosslinkers such as aldehyde, [30][31][32][33][34] isocyanate, [35][36][37] and carbodiimide [38][39][40][41][42] are introduced to enhance the mechanical properties of collagen. Glutaraldehyde creates reversible intra-and intermolecular crosslinks, causing release of glutaraldehyde monomers.…”

Development of a cellulose-based prosthetic mesh for pelvic organ prolapse treatment: In vivo long-term evaluation in an ewe vagina model

“…However, the fibers cross-linked in those systems showed inadequate water stability and collapsed into films in aqueous or high-humidity environments [ 32 ]. Glutaraldehyde is a known crosslinker of hydroxyl and amine groups, which are abundant in cellulose and collagen [ 33 , 34 ].. In the present study, glutaraldehyde was used as a cross-linking agent, because it has been proven to be efficient and useful in previously published study [ 16 ].…”

Hydrogel, Electrospun and Composite Materials for Bone/Cartilage and Neural Tissue Engineering

“…To overcome this problem, many of them are treated with crosslinking agents to provide adequate mechanical properties, stability in physiological conditions and controlled degradation rate [28]. Nevertheless, such commonly used crosslinkers as glutaraldehyde or formaldehyde are toxic in contact with cells, whereas their complete removal after the process is often impossible [29]. Currently investigated alternatives are physical crosslinking methods, which induce physical bonding under specific environmental changes (e.g., temperature, pH, UV) [30].…”