Seems like the special sauce is nothing at all but what seems to be well known prior art:

    [0038] In preparing the xenograft for use, the tendon is surgically 
    dissected and removed from the paratenon (tendon sheath). The tendon is 
    composed mostly of an extra-cellular collagen matrix, which is non-
    immunogenic. The tendon may therefore require no denaturing 
    (decellularisation) prior to implantation into a mammal. In some 
    embodiments, the tendon may be subjected to a decellularisation process 
    prior to implantation. In removing the cells from the tendon, the 
    immunogenic antibodies within the cells are also removed, thus rendering the 
    tendon non- immunogenic. Methods of decellularisation of tendon tissue are 
    known in the art. Such methods include physical, chemical and enzymatic 
    treatments, wherein the cells within the tendon are lysed, leaving an 
    undamaged extracellular matrix having the same physical and biochemical 
    properties as the natural tissue.