Crosslinking and modification of dermal sheep collagen using 1, 4-butanediol diglycidyl ether.
Crosslinking of dermal sheep collagen (DSC) was accomplished using 1, 4-butanediol diglycidyl ether (BDDGE). At pH values > 8.0, epoxide groups of BDDGE will react with amine groups of collagen. The effects of BDDGE concentration, pH, time, and temperature were studied. Utilization of a 4-wt % BDDGE instead of 1-wt % resulted in a faster reaction. Whereas similar values of shrinkage temperature were obtained, fewer primary amine groups had reacted at a lower BDDGE concentration, which implies that the crosslinking reaction had a higher efficacy. An increase in pH from 8.5 to 10.5 resulted in a faster reaction but reduced crosslink efficacy. Furthermore, an increase in reaction temperature accelerated the reaction without changing the crosslink efficacy. Crosslinking under acidic conditions (pH < 6.0) evoked a reaction between epoxide groups and carboxylic acid groups of collagen. Additional studies showed that no oligomeric crosslinks could be formed. However, hydrolysis of the epoxide groups played a role in the crosslink mechanism especially under acidic reaction conditions. The macroscopic properties of these materials were dependent on the crosslinking method. Whereas a flexible and soft tissue was found if crosslinking was performed at pH < 6.0, a stiff sponge was obtained under alkaline conditions. Reaction of DSC with a monofunctional compound (glycidyl isopropyl ether) led to comparable trends in reaction rate and in similar macroscopical differences in materials as observed with BDDGE.
Department of Chemical Technology, and Institute of Biomedical Technology, University of Twente, P.O. Box 217, 7500 AE Enschede, The Netherlands.
R
R
Zeeman
P J
PJ
Dijkstra
P B
PB
van Wachem
M J
MJ
van Luyn
M
M
Hendriks
P T
PT
Cahalan
J
J
Feijen
D000818:Animals; D002072:Butylene Glycols / Q000737:chemistry*; D003094:Collagen / Q000737:chemistry*; D003432:Cross-Linking Reagents; D020405:Dermis / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D012756:Sheep; D013696:Temperature
D002072:Butylene Glycols; D003432:Cross-Linking Reagents; D003094:Collagen; C014376:1,4-bis(2,3-epoxypropoxy)butane