How Scientists Tackle Chronic Osteomyelitis using Bioactive Glass

If you asked doctors how to treat chronic osteomyelitis, they would likely all say the same thing: antibiotics, amputation, or bone grafts. However, if you asked the scientists at Galeazzi Orthopedic Institute, you might get told that the best way to treat chronic osteomyelitis is with bioactive glass S53P4, one of the most recent and promising medical advancements for bone treatment. But what makes bioactive glass S53P4 so special? 

First off, we need to understand what osteomyelitis is, and subsequently what chronic osteomyelitis is. Osteomyelitis is an infection of the bone tissue which can occur due to bone damage, surrounding soft tissue damage, or nearby surgery which allows pathogens to penetrate the protective outer layer of the bone. Once within the bone, pathogens can cause varying degrees of bone loss as the infection progresses. Ultimately, this bone loss can result in limb amputation, sepsis, or even death as a progressed infection can result in organ failure. 

As mentioned above, the traditional treatments for osteomyelitis consist of antibiotics to kill the responsible pathogen and stop the spread of the infection; however, antibiotics are not always the best option as they can affect other microorganisms in the body. Furthermore, overuse of antibiotics in a clinical setting has allowed for the development of antibiotic resistant pathogens, such as methicillin resistant staphylococcus aureus (MRSA), which will eventually render antibiotics useless. Furthermore, higher degrees of bone loss can result in a very weak bone which cannot be treated with antibiotics alone. So, what are our other options? 

Clinically, if you want to avoid losing a limb, the next best options would be antibiotic loaded polymethylmethacrylate beads (PMMA) or bone grafting. Both of these methods work through the surgical removal of the necrotic bone tissue and the replacement of that bone tissue with PMMA or fresh bone from a graft.

However, there are some drawbacks as these methods are only designed to fill the bone cavity left behind from the infection, provide limited local antibiotics, and take a long time to produce results. Sadly, bone doesn’t grow overnight! So, what if there was something that could fill the bone cavity, stimulate bone growth, and was naturally antibiotic resistant?

Enter bioactive glass S53P4 (BAG S53P4). Bioactive glass itself is a silica based biodegradable glass which has been shown to have antibiotic, osteoconductive, and angiogenic properties. Which is essentially a way of saying it stimulates bone growth and blood vessel growth all while repelling those pesky pathogens! BAG S53P4 takes it a step further and is composed of SiO2, Na2O, CaO, and P2O5 which further stimulates bone growth by chemically binding to surrounding bone. This almost sounds too good to be true, so researchers at Galeazzi Orthopedic Institute set out to understand how BAG S53P4 is so effective and determine its safety in a clinical setting. 

To determine the source of BAG S53P4s antibiotic properties and to evaluate its safety, the research team took 27 patients with chronic long bone osteomyelitis from antibiotic resistant pathogens and treated them using the bioactive glass.  From their study, they were able to determine that the antibiotic resistant properties of BAG S53P4 stems from its contact with an aqueous solution. By contacting an aqueous solution, BAG S53P4 activates the release of ions which increase the surrounding pH. This increased pH creates a hostile environment for bacterial growth stopping infection in its tracks. As a result, 90% of the treated patients showed no signs of infection after 18 months. X Rays of the patient treated with BAG S53P4 were also taken over the course of 18 months. From these X Rays, the team was able to determine that the vascularization and bone growth seen in these patients far surpassed that of previous methods and was equally safe in its application. 

Ultimately, this research determined that BAG S53P4 was a safe and effective treatment for patients suffering from chronic osteomyelitis. So next time you’re asked how to treat chronic osteomyelitis, consider the less traditional route and give BAG S53P4 a try!  

Source:

Drago, L., Romanò, D., De Vecchi, E., Vassena, C., Logoluso, N., Mattina, R., & Romanò, C. L. (2013). Bioactive glass BAG-S53P4 for the adjunctive treatment of chronic osteomyelitis of the long bones: An in vitro and prospective clinical study. BMC Infectious Diseases, 13(1), 1-8.

https://pubmed.ncbi.nlm.nih.gov/24325278/