A system for monitoring the response of uniaxial strain on cell seeded collagen gels

The success of cell seeded constructs for the repair of collagenous tissues may be improved by the use of mechanical stimulation in vitro. A mechanica l loading apparatus, termed the cell straining system, was developed accord ing to a set of design criteria, to enable cell seeded constructs to be cyc lically loaded in tension. A suitable cell seeded collagen gel model system was used to characterise the apparatus. These gels were subjected to a cyc lic strain of 10% superimposed on two separate tare loads of 2 and 10 mN, w hile being maintained in cell culture conditions. The computer controlled a pparatus was shown to be capable of monitoring the individual loads on six specimens simultaneously, to an accuracy of 0.02 mN. Results indicated a wi de variability between individual specimens. Following cyclic loading, the cell seeded collagen gels exhibited an increase in structural stiffness com pared with the unloaded controls. This novel and versatile apparatus will p rovide a means of enhancing structural and mechanical integrity of tissue e ngineered repair systems. (C) 2000 IPEM. Published by Elsevier Science Ltd. All rights reserved.