Effects of Pressure upon Collagen

Abstract

DURING recent investigations into the micro-structure of collagen fibres, we have utilized the ‘crushing technique’ of Boddy¹, and combined this with the interferometric method due to Merton². By these means, changes in structure due to physical or chemical effects may be readily observed, and we have found that liquid globules are exuded from air-dried collagen fibre bundles under pressures in the region of 2,500 kgm./cm.². Fig. 1 shows the appearance of a fibre bundle originally 35 µ in diameter, after the application of a load of approximately 2,000 kgm./cm.². The globules are seen on the surface and at the edges of the bundle. These appear as discrete globules after the release of the pressure, if it has been sufficient to force the film of displaced liquid to an excessive distance. The effect of increasing the pressure to approximately 2,500 kgm./cm.² is shown in Fig. 2, where the displaced liquid continues to ‘wet’ the fibres at the perimeter of the main pressure area. The portions of fibres from which liquid has been displaced appear dark as they are virtually dry-mounted. Further work is in progress upon the nature of this liquid.