Fetal surgery is risky business as the amniotic sac may be pierced by an endoscopic tool, raising prospects for attendant complications such as premature labor or fetal morbidity. Surgeons are challenged to seal the fragile amniotic sac post-operation because medical adhesives do not perform effectively on wet surfaces.
Taking inspiration from a basic bivalve, University of California-Berkeley researchers formulated a surgical glue that could reduce the hazards of these procedures. They sought to replicate the ability of mussels to cling to slippery rocks by using a chemical found in the creature’s foot. The adhesive ingredient—dihydroxyphenylalanine—was infused into a special polymer that can dissolve in a biocompatible solvent. The resulting formulation can be delivered with a syringe, and its chemistry eliminates the use of crosslinkers, which can be toxic to fetuses, previously required to develop surgical hydrogels.
The glue was tested with pieces of a membrane that surround a cow’s heart as a model of the amniotic sac. After application with a syringe to overlapping pieces of the wet, filmy tissues, the solution became rubbery, set within an hour and effectively held the pieces together.
“Repairing a hole in the amniotic sac is a daunting engineering challenge,” says researcher Philip Messersmith, Ph.D. “So in addition to the novel polymer that we’re making, we’re approaching its delivery from a new angle, which is what we call pre-sealing. Injecting the liquid polymer between the inner wall of the uterus and the amniotic sac and letting it harden before surgery could provide the mechanical support needed to prevent the hole from tearing and causing a catastrophic rupture.”
The researchers are now perfecting the glue, examining biocompatibility and planning preclinical testing in animals.
The research was presented at the 254th American Chemical Society National Meeting & Exposition, August 20-24, 2017, in Washington, D.C.