Mechanical Properties of Mineralized Collagen Type I Rat-Tail Tendon Fascicles

Type I collagen fibers transmit forces, dissipate energy, and prevent mechanical failure in normal tissues. Mineralization of collagen fibers is proposed to strengthen these structural proteins as a possible therapeutic option for small tears in soft tissues such as cemental tears in periodontal ligaments.  In the present study, collagen fascicles extracted from the tail tendons of male Sprague-Dawley rats were tested in a MiniMat tensile tester at different strain rates. The fascicles were previously immersed in SBF to induce mineralization and were maintained in a moist condition during mechanical testing. Mineralization of the fascicles resulted in an increase in the modulus of elasticity and tensile strength with minimal change in percentage elongation to failure. From SEM/EDS, calcium phosphate deposits formed on the fascicles indicating a high probability of intrafibrillar mineralization resulting in the observed improvement in mechanical properties.