JUL 12, 2016 8:00 AM PDT

Face implants fight infection from gunshots

Researchers developing temporary implants for facial reconstruction are incorporating a unique way to deliver time-released antibiotics to protect against infection while a patient heals.
 

Wound infections from gunshot injuries to the face are common—and soldiers are at particular risk, as battlefield injuries are often prone to infection from multidrug-resistant species of bacteria that invade between the time of injury and treatment. Image Credit: U.S. Army Photo by Sgt. Marcus Fichtl, 2nd ABCT, PAO 4th Inf. Div./Flickr


Antonios Mikos, professor of bioengineering and chemical and biomolecular engineering at Rice University, develops materials to help repair severe craniofacial injuries from trauma or pathological defects like tumor removal. Specialized plastic space maintainers are designed to keep a pocket for new bone open while the overlying soft tissue heals. In later surgery, the implant is removed to make way for reconstruction of the bone.

In a new advance, porous polymethylmethacrylate (PMMA) implants are filled with a gel that leaches a protective antibiotic to surrounding tissue, which protects the tissue from infection for several weeks.

Researchers describe the implants in a paper published in Biomaterials Science.

“Infection is an important problem that needs to be considered with medical devices because bacteria can prevent the body from being able to heal,” Mikos says. “If the infection gets too severe, it can even cause tissues that were previously healthy to die.”

Infections from the external environment and from neighboring structures such as the nasal passages, the sinuses, and the mouth can attack vulnerable tissue, researchers say. Wound infections from gunshot injuries to the face are common—and soldiers are at particular risk, as battlefield injuries are often prone to infection from multidrug-resistant species of bacteria that invade between the time of injury and treatment.

Researchers have experimented with porous implants but found they are susceptible to invasion by infectious bacteria. The new solution fills the pores at the point of care with a thermogel that infuses the spacer as a liquid and turns into a gel when exposed to body heat.

The thermogel itself is special. It consists of a block copolymer, a self-assembling combination of two polymers that is also under investigation for the controlled release of chemotherapy drugs.

“Block copolymers can offer a lot of benefits since they are designed to take advantage of the strengths of individual polymers,” Mikos says. “The block copolymer we used for our study was designed to be able to take on water, become a gel at body temperature, and slowly degrade over the course of implantation.”

Porous implants have been tested in humans, but PMMA with thermogel has not. Researchers infused the gel with colistin, a last-resort antibiotic with strong side effects. The PMMA and copolymer combination enabled tight control of its release without disrupting its antibacterial activity. In testing, the implants initially released a burst of the antibiotic through diffusion. Over time, degradation of the copolymer would continue to release lesser amounts of the drug for up to 28 days.

The thermogel can be customized at the time of implantation with the appropriate antibiotics, which also affect the rate and duration of release, before infusion into the prefabricated spacer.

Source: Rice University

This article was originally published on futurity.org.
About the Author
  • Futurity features the latest discoveries by scientists at top research universities in the US, UK, Canada, Europe, Asia, and Australia. The nonprofit site, which launched in 2009, is supported solely by its university partners (listed below) in an effort to share research news directly with the public.
You May Also Like
MAR 11, 2021
Immunology
Bye-Bye Burning: A New UTI Vaccine
MAR 11, 2021
Bye-Bye Burning: A New UTI Vaccine
Researchers have developed a vaccine that “trains” the bladder to fight back against the bacteria that cause ...
APR 13, 2021
Immunology
Food-borne Fungus Impedes Gut Healing
APR 13, 2021
Food-borne Fungus Impedes Gut Healing
In a recent study, researchers discovered that a fungus present in cheese, processed meats, beer, and other fermented fo ...
APR 22, 2021
Drug Discovery & Development
mRNA Covid Vaccines May Protect Against New Strains and Common Cold
APR 22, 2021
mRNA Covid Vaccines May Protect Against New Strains and Common Cold
Researchers from Johns Hopkins have found that the mRNA Covid vaccines developed by Pfizer and Moderna not only work wit ...
MAY 20, 2021
Immunology
Why Delaying the 2nd COVID Shot is Paying Off for Some
MAY 20, 2021
Why Delaying the 2nd COVID Shot is Paying Off for Some
A new study indicates that delaying the second “booster” dose of the Pfizer-BioNTech COVID vaccine (to 11-12 ...
MAY 31, 2021
Immunology
Engineering Faster, More Agile T Cell Cancer Fighters
MAY 31, 2021
Engineering Faster, More Agile T Cell Cancer Fighters
Cell therapies use engineered T cells extracted from the patient’s own immune system to rally an attack on tumors. ...
JUN 08, 2021
Immunology
Fueling the Immune System's Killers
JUN 08, 2021
Fueling the Immune System's Killers
There’s a group of “killers” protecting your body against infections and eliminating potentially cance ...
Loading Comments...