This gradual release enables control of protein expression for days or even months, recreating the sequence of events that naturally occurs in bone growth. Developed by biomaterials expert Robert Levy, M.D., professor of pediatrics and of pharmaceutics, the gel is based on the same material used in biodegradable sutures. Inside the body, the polymer molecules undergo a sort of surface erosion similar to what happens to a hard candy that melts in the mouth. When the molecules dissolve, the DNA is released. Once the DNA is taken up by the granulation cells, these cells become micro-pharmacies, dispensing the healing proteins and hormones needed to make new bone tissue.
Studies using the newer copolymer DNA vector are under way.
The team hopes to have the technology in clinical trials within two years. The patient is cleaned up, stabilized and put to bed. The bone-growing proteins are programmed to start being released three days later, when the granulation tissue appears. All of these proteins are released within about eight weeks the time it takes for a normal fracture to substantially heal. In addition to bone, the technique eventually may be used to speed healing in other tissues, from torn tendons and cartilage to surgical wounds, Bonadio says.