UCLA dental school researchers create nanoparticle that could improve bone defect treatment

A team of researchers at the University of California, Los Angeles School of Dentistry has developed a nanoparticle that could improve treatment for bone defects.

The researchers — Min Lee, Ph.D.; Chung-Sung Lee, Ph.D.; Soyon Kim, Ph.D.; Jiabing Fan, M.D., Ph.D.; Hee Sook Hwang, Ph.D.; and Dr. Tara Aghaloo, M.D., Ph.D., who is a member of the ADA Council on Scientific Affairs — created a new type of liposome called a sterosome that successfully activated bone regeneration on its own, without needing therapeutic drugs, in laboratory tests using mice with bone defects, according to a news release from UCLA.

Currently, the standard treatment for bone defects is bone grafts, but they can cause complications. Liposomes, which can be used to administer nutrients and pharmaceutical drugs in the body, have recently been explored for possible use in bone tissue engineering.

Liposomes can be unstable, and it can be difficult to control how and when they release drugs. To help improve their stability and enhance their ability to form bone in the body, the researchers replaced the cholesterol in liposomes with oxysterol, a type of cholesterol that helps with skeletal development and bone healing, to develop sterosomes, the release stated.

After finding the sterosomes activated bone regeneration, the researchers added the nanoparticles to a tissue engineering scaffold, which is a structure used to move and grow naturally occurring stem cells that is matched to the site of the defect and used during bone graft procedures. They loaded the sterosomes with a bone-building drug called purmorphamine and immobilized them onto the scaffold to ensure they stayed concentrated in the defective areas and released the drugs where they were most needed for as long as possible, according to the release.

In a six-week study using mice with bone defects in their skulls, the researchers saw an average reduction of about 50% in the size of the defects after the drug-loaded scaffold was implanted.

The study was published April 22 in the journal Science Advances. It was funded by the National Institute of Dental and Craniofacial Research, U.S. Department of Defense and Musculoskeletal Transplant Foundation Biologics.