Fistulas are abnormal connections between two body parts that can impair the quality of life. The use of
biological glues represents the least invasive procedure to fill the
fistula; however, it is limited by the need of multiple
injections, the persistence of
infection and the failure in the treatment of high-output
fistulas. We describe herein the use of an
injectable nanocomposite hydrogel that is able to form in situ a tissue-mimicking matrix as an innovative material for the treatment of
esophageal fistulas.
Injectable hydrogels that have the dual advantage of being implantable with a minimally invasive approach and of adapting their shape to the target cavity, while the introduction of mesoporous
silica nanoparticles opens the possibility of
drug/biomolecules delivery. The
hydrogel is based on
hyaluronic acid (HA), the crosslinking process occurs at physiological conditions leading to a
hydrogel made of >96% by water and with a large-pore micro-architecture. The kinetic profile of the
hydrogel formation is studied as a function of HA molecular weight and concentration with the aim of designing a material that is easily
injectable with an endoscopic needle, is formed in a time compatible with the
surgical procedure and has final mechanical properties suitable for cell proliferation. The in vivo experiments (porcine model) on esophageal-
cutaneous fistulas, showed improved healing in the animals treated with the
hydrogel compared with the control group.