Injectable Microgel Reduces Blood Loss in Infant Surgery

Bleeding during neonatal surgery remains difficult to manage because infant blood forms clots differently than adult blood. Transfusing adult blood can offset losses but may provoke excessive clotting and thrombosis in infants. This mismatch complicates perioperative decision-making and increases risk. To help address this challenge, biomedical engineers have developed an injectable microgel designed to support infant hemostasis during surgical procedures.

The material, called B-knob triggered microgels (BK-TriGs), was created in the Lampe Joint Department of Biomedical Engineering at North Carolina State University and the University of North Carolina at Chapel Hill. BK-TriGs are engineered particles studded with short B‑peptide sequences that link fibrin molecules, the primary clotting protein. After injection the particles absorb water and become soft hydrogels that mimic platelet mechanics to promote fibrin network formation and limit bleeding.

Investigators evaluated BK‑TriGs in vitro using microfluidic devices and human plasma from adults and infants. The particles improved clotting in infant plasma more than in adult plasma. The authors reported that this result aligned with the infant‑specific role of B peptides in clot formation.

Efficacy was then tested in lab mice genetically engineered to lack fibrinogen, the precursor to fibrin. Researchers first introduced infant fibrinogen to model infant‑like hemostasis before surgical bleeding assays. In this model BK‑TriGs reduced blood loss by 50–60% compared with controls and outperformed other tested options. The study was published on April 3 in Science Advances.

Planned work will compare BK‑TriGs with available hemostatic therapeutics as standalone agents or in combination. The researchers noted that clinical use remains distant and that further studies are needed to rule out unforeseen clotting risks. They also indicated that manufacturing the particles could be relatively inexpensive compared with blood products.

“We found that the BK‑TriGs outperformed any of the other options we tested at reducing blood loss. Specifically, the BK‑TriGs reduced blood loss by 50–60% compared to the control group," said Ashley Brown, Lampe Distinguished Professor of Biomedical Engineering, Lampe Joint Department of Biomedical Engineering, North Carolina State University and the University of North Carolina at Chapel Hill.

“The results we’re reporting here are exciting, but we are still far removed from clinical use. We need to make sure there are no unforeseen risks associated with blood clotting. But if we do find BK‑TriGs are safe and effective, we’re optimistic this could be a cost‑effective way to make surgery safer for infants. Manufacturing the BK‑TriG particles would be relatively inexpensive—certainly in comparison to blood products,” added Brown.

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Lampe Joint Department of Biomedical Engineering