Tech Briefs

Scaffolds loaded with a particular antibiotic prevent two infection-causing bacteria.

A study led by scientists from the Regenerative, Modular, and Developmental Engineering Laboratory (REMODEL) and the Science Foundation Ireland Centre for Research in Medical Devices, CÚRAM, has developed a new type of implantable device to provide localized drug treatment and prevent infection. It has already proven effective against two types of major device infection bacteria.

Antimicrobial activity of Ran- and Cef-loaded scaffolds. Ran, even at the highest concentration of 500 μg ml−1, was completely ineffective even against the lowest (106 CFU/ml) E. coli and S. epidermidis concentration. Cef, at 100 μg ml−1, was effective against both low (106 CFU/ml) and high (108 CFU/ml) E. coli and S. epidermidis concentrations. (Credit: Biomedical Materials/IOP Publishing).

Publishing their results in the journal Biomedical Materials, the NUI Galway research team show that stabilized collagen scaffolds loaded with a particular antibiotic were able to prevent two infection-causing bacteria, Escherichia coli and Staphylococcus epidermidis from forming.

Lead author of the paper, Dr Dimitrios Zeugolis from NUI Galway’s REMODEL and CÚRAM says, “Implant infections remain a major healthcare problem. They can require long hospitalization periods to disturb and treat bacterial biofilm formation. There can also be a need for additional surgeries to remove or replace the infected implant, which if not done in time, may lead to sepsis. Although localized drug treatment via an implanted scaffold has shown promise, the ideal scaffold cross-linking (to initially withstand the aggressive infection environment) and drug (to fight against infection) have not, until now, been found.”

The NUI Galway research team, including Dr. Gerard Wall of Microbiology and CÚRAM, first ventured to identify the optimal hexamethylene diisocyanate (HMDI) concentration that would offer suitable biomechanical, biochemical, and biological properties. HMDI was chosen as it is a Food and Drug Administration approved cross-linking agent for collagen-based medical devices.

They then loaded the optimally crosslinked collagen scaffolds with variable concentrations of the antibiotics Cefaclor and Ranalexin to identify the minimum effective concentration required to inhibit the growth of Escherichia coli and Staphylococcus epidermidis, two of the most frequently encountered bacteria in medical device infection.

“The development of our drug-loaded collagen device marks an important step forward,” says Dr. Zeugolis. “First, the sustained and localized delivery system that we developed avoids issues associated with systemic drug administration, such as antibiotic resistance. Further, we contributed towards finding a solution against a severe economic burden to healthcare systems internationally.”

Professor Abhay Pandit, Scientific Director of CÚRAM adds, “CÚRAM’s goal is to develop affordable transformative solutions to improve quality of life for people suffering from chronic illnesses. Dr. Zeugolis’ work continues to push towards this goal and will have real impact for patients and for the future medical device development.”

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