The kirigami-inspired stents could be a long-term solution minimising the need for those with chronic conditions to take medication.
Researchers from Brigham and Women’s Hospital and MIT have designed a stretchable stent with pop-out needles for use in drug delivery in tubular organs, such as the airway and the gastrointestinal (GI) system.
Practitioners can fill the plastic-coated rubber stent with air in order to deliver drugs at specific locations throughout the body.
The research was a collaboration between Brigham and Women’s Hospital, Massachusetts General Hospital and MIT, and was partly funded by the Karl Von Tassel (1925) Career Development Professorship and the Department of Mechanical Engineering at MIT.
It was driven by the need to meet therapeutic requirements in disorders such as inflammatory bowel disease.
While interventions exist for conditions affecting tubular organs, applying the treatment is a different matter. Previous methods of drug administration have struggled to apply the intervention to these internal organs, as the shape and location inside the body can make it difficult to coat the afflicted area.
Instead, current practice often involves administering drugs that can affect entire systems, sometimes with unwanted side effects. Other balloon-based systems are location specific, but struggle in retention of the drug over longer periods of time. This new stent is intended to overcome these issues by facilitating precise and long-lasting drug delivery.
Based on kirigami (a form of origami that includes cutting the paper), the stent isn’t required to be implanted in the body, and instead expands temporarily where it is needed.
The stent is designed to pop out needles when the silicon-based tube is stretched. The needle surfaces are loaded by pipetting the particle solution onto the stents to create a uniform spread of the intended intervention.
By applying air pressure, the stent is transformed from an easily inserted flat shape to a complex, three-dimensional structure. Resembling snakeskin in texture, the appropriate design was identified through a series of finite element simulations and experiments.
These novel design elements are how the researchers intend to reach many organs in the body through a minimally invasive procedure.
Sahab Babaee is an MIT research scientist and lead author of the paper that was published in Nature Materials on Monday (14 June).
Babaee and his colleagues wrote that: “Such systems have the capacity to provide long-term local therapy for chronic conditions while minimising the actual need to take a medication, thereby potentially maximising adherence.”
Early animal models were tested in the oesophagi of pigs and demonstrated maintained drug concentrations for the week that followed. The researchers plan to continue animal testing for drugs used in the treatment of GI disorders, as well as refining the manufacturing process with the eventual goal of widespread clinical application.