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.
Zeeman
R
R
Department of Chemical Technology, and Institute of Biomedical Technology, University of Twente, P.O. Box 217, 7500 AE Enschede, The Netherlands.
Dijkstra
P J
PJ
van Wachem
P B
PB
van Luyn
M J
MJ
Hendriks
M
M
Cahalan
P T
PT
Feijen
J
J
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