A method of achieving tissue changes in bone or bone-derived organic tissue, in which method bone or bone-derived organic tissue is provided, an interfacing agent is applied to the bone or bone-derived organic tissue, and electromagnetic energy is applied to the interfacing agent. The interfacing agent can include collagen, preferably bone-derived collagen, and a therapeutic agent. In a related embodiment, a method of treating bone tissue is provided wherein a bioactive interfacing agent is placed between the bone segments of the bone tissue to be treated.