Tensile Strength of Single Collagen Fibrils Isolated from Tendons

Tensile failure properties of single collagen fibrils were determined using our original tensile test method. Fibrils were directly isolated from the fascicles of mouse tail tendons. Both the ends of each fibril were wound onto the tips of two microneedles several times using micromanipulators. The fibril and tips were immersed in physiological saline solution. Then, the fibril was stretched to failure by moving the one microneedle. During tensile testing, the fibril was firmly attached to the tips of the microneedles, and broken between the tips with no slippage observed. The diameter of tested 10 fibrils was 410±60 nm (Mean±S.D.). The stress-strain curves of these fibrils were almost linear. Their tensile strength and failure strain were 100±32 MPa and 34±11%, respectively. These values were approximately 480 and 190% of those of the fascicles with the diameter of 81±12 μm, respectively.