Biodegradable polymer could help heal the bones of patients with orthopedic injuries

A plastic derived from cornstarch combined with a volcanic ash compound, Montmorillonite clay, could help heal the bones of hundreds of thousands of patients with orthopedic injuries who need bone replacement after tumor removal, spinal fusion surgery or fracture repair.

Traditional bone graft procedures require surgeons to remove bone from another part of the patient's body to heal the affected area and encourage new bone growth. Harvesting a patient's bone can result in complications at the harvest site. Some surgeons also use bone donated from cadavers. However, there is a limited supply of donor bones available.

Researchers at Beaumont Hospital - Royal Oak will publish their preclinical findings in the journal Nanomedicine. Kevin Baker, Ph.D., director, Beaumont Orthopaedic Research Laboratories, worked on the study with Rangaramanujam Kannan, Ph.D., of Johns Hopkins, formerly with Wayne State University.

Using a synthetic material will likely lead to a reduction in the surgery complication rate. The patient will only need to heal from one surgery because harvesting bone would not be necessary.

The goal is to use the material without any additional permanent hardware placed in a patient's body. Current procedures often require a metal or non-resorbable plastic implant because traditional bone grafts are not strong enough without the added support.

"This improves outcomes for the patient because internal hardware can pose a challenge with respect to being a potential site for infection, and can complicate MRI and CT imaging tests. In addition, from the surgeon's perspective, not having to worry about a large piece of metal or hard plastic in the area may make future procedures easier," Baker says.

The biodegradable polymer, reinforced with Montmorillonite clay nanoparticles for strength, dissolves in the body within 18 months. As the material dissolves, new bone formation takes its place. The material is created by injecting the polymer-clay mixture with carbon dioxide, resulting in an implant that looks like foam, but is rigid like bone. Researchers designed the bone material to be porous, just like actual human bone.

The material is still in the research phase and likely won't be available to patients for several years.