Nanoparticles To Open New Doors In Bone Defect Treatment.

Readily available and reliable bone grafts are required for craniofacial surgeries as bone regeneration is an important clinical issue accompanying aging population. Bone injuries are particulary prevalent among elderly.

Researchers at the University of California Los Angeles, School of dentistry have developed a nanoparticle that could improve treatment for bone defects caused by traumatic injury, infection, osteoporosis, or tumor removal.

At present, the standard treatment for bone defects is a Bone graft. Bone grafting involves transplanting healthy bone from another part of the body to repair the damaged area.

However, the procedure can cause complications. These complications include:

• Infection.
• Bleeding.
• Nerve damage.

In order to combat this complication, the researchers turned focus towards liposomes. Liposomes are tiny spherical sacs that are derived from naturally existing lipids.

Liposomes have been in use in medical field since early nineties for the treatment of cancer and many infectious diseases before they were considered to be used bone tissue engineering. They can be used to administer nutrients as well as pharmaceutical drugs in the body and can easily enter cells to administer their valuable cargo.

But they come with their own drawbacks which are:

1. Instability.
2. Difficulty in controlling when and how they release drugs.

To help improve their stability and enhance their ability to form bone in the body, the UCLA researchers developed a new type of liposome called a sterosome. (The name is inspired by the fact that they contain a high concentration of steroids.)

How are sterosomes produced?

To produce the sterosomes, the scientists replaced cholesterol, an important component of liposomes, with oxysterol, a type of cholesterol that has a key role in skeletal development and bone healing.

When tested on mice having bone defects, these sterosomes were found to successfully activate bone regeneration on their own, without need of any therapeutic drug.

"Liposomes are generally made from pharmacologically inactive substances," said Min Lee, the paper's corresponding author and a professor of biomaterials science at the dental school. "Including oxysterol into our liposomal formulation not only increased nanoparticle stability but also stimulated cells to develop into bone-forming cells."