The stabilization of fibrillar collagen matrices with 3,4-dihydroxyphenylalanine

• Published in: Journal of biomedical materials research 1991-07, Vol.25 (7), p.799-811
• Main Authors: Gade, Jay N., Fellman, Jack H., Peter Bentley, J.
• Format: Article
• Language: English
• Subjects: Biocompatible Materials; Biological and medical sciences; Bioprosthesis; Collagen - chemistry; Dihydroxyphenylalanine - pharmacology; Freeze Drying; Gels - chemistry; Medical sciences; Pepsin A - pharmacology; Radiotherapy. Instrumental treatment. Physiotherapy. Reeducation. Rehabilitation, orthophony, crenotherapy. Diet therapy and various other treatments (general aspects); Technology. Biomaterials. Equipments. Material. Instrumentation; Temperature; Tensile Strength
• ISSN: 0021-9304; 1097-4636
• DOI: 10.1002/jbm.820250702

Pepsin‐treated type I collagen fibrils were reconstituted by warming to 37°C in the presence of DOPA at a concentration of 1 × 10−3M. Following a 1‐1.5‐h lag period tdhe “gels” became progressively stabilized as indicated by an inability to disperse these at 0°C. Following 24 h of incubation at 37°C, the DOPA‐collagen gels were insoluble in dilute acetic acid even under denaturing conditions. The effect on both gel stability and solubility was concentration‐dependent and was maximum at 1 × 10−3M. Gel solubility changes were significant, with the greatest change occurring between concentrations of 3.1 × 10−5M. DOPA exposure did not alter the fibrillar banding pattern seen at the electron microscopic level. Collagen felts prepared by lyophilization of DOPA‐collagen gels demonstrated an increase in shrinkage temperature which after 24 h exceeded that of rat tail tendon. Preformed collagen felts incubated for 24 h in the presence of 1 mM DOPA also had a greatly increased shrinkage temperature. Pepsin‐treated collagen control felts were consistently unstable at 37°C. The tensile properties of DOPA‐collagen felts were altered with respect to control felts in a time dependent manner. The wet tensile strength increased to four times that of control after 3 days of incubation at 37°C. Matrix extensibility initially increased to 1.5 times that of control felts after 4 days of incubation at 37°C, but decreased to below control values following 6 additional days of incubation. These properties suggest that DOPA may be useful as a stabilizing agent of collagen biomedical prostheses.