Effect of physical crosslinking methods on collagen-fiber durability in proteolytic solutions

✍ Scribed by Weadock, Kevin S. ;Miller, Edward J. ;Keuffel, Eric L. ;Dunn, Michael G.

• Publisher: John Wiley and Sons
• Year: 1996
• Tongue: English
• Weight: 541 KB
• Volume: 32
• Category: Article
• ISSN: 0021-9304
• DOI: 10.1002/(sici)1097-4636(199610)32:2<221::aid-jbm11>3.0.co;2-m

✦ Synopsis

We previously demonstrated that ultraviolet (UV) or dehydrothermal (DHT) crosslinking partially denatured fibers extruded from an insoluble type I collagen dispersion. In this study denaturation effects were evaluated by measuring collagen-fiber sensitivity to trypsin. Shrinkage-temperature measurements and sensitivity to collagenase served as indices of crosslinking. UV or DHT crosslinking increased the collagen-fiber shrinkage temperature, resistance to degradation in collagenase, and durability under load in collagenase. However, in trypsin solutions, solubility was significantly increased for UV ( ~1 1 % )

or DHT (215%) crosslinked fibers compared with uncrosslinked fibers (%4%). Size-exclusion chromatography indicated that no intact collagen a-chains were present in the soluble fraction of fibers exposed to trypsin (MW <1 kD). Interestingly, UV-crosslinked collagen fibers remained intact an order of magnitude longer (4840 +-739 min) than DHT-crosslinked (473 ? 39 min) or uncrosslinked (108 2 53 min) fibers when placed under load in trypsin solutions. These data indicate that mechanical loading during incubation in a trypsin solution measures denaturation effects not detected by the trypsin-solubility assay. Our results suggest that DHT-crosslinked collagen fibers should not be used as load-bearing implants. UV-crosslinked fibers may retain more native structure and should exhibit greater resistance to nonspecific proteases in viva