Injectable Microgel Mimics Infant Clotting to Reduce Bleeding in Pediatric Surgery

Biomedical engineers have created an injectable microgel designed to match the way infants form clots, reporting sizable reductions in bleeding in preclinical tests. The early work addresses a long‑standing challenge in pediatric surgery: infants do not clot like adults, yet operating rooms often must rely on blood products sourced from adults. The findings land as children’s hospitals and regulators look for safer, more tailored tools to manage bleeding in neonatal intensive care units and high‑risk surgeries.

A lab-built microgel tuned to infant clotting physiology

The team engineered B‑knob-triggered microgels (BK‑TriGs) that present short “B peptide” sequences used by fibrin-blood’s primary structural clotting protein-to build fibrin networks. The particles swell into soft hydrogels in aqueous environments, aiming to mimic key platelet‑like mechanics while concentrating the infant‑relevant peptide signals that drive clot formation. In principle, the material is meant to support the body’s own clotting processes rather than replace them, acting as a scaffold that infant clotting factors can latch onto more efficiently.

But if you give adult blood to an infant, the difference in adult hemostasis versus infant hemostasis can lead to too much clotting, that can increase the likelihood of thrombosis, where blood clots form in the lungs or elsewhere and put the baby at risk.

“My research team has done a lot of work on surgery-related bleeding in newborns, and we wanted to develop a therapeutic intervention that would reduce bleeding and – by extension – reduce the need for infants to receive adult blood transfusions during surgery,” says Brown, who is the Lampe Distinguished Professor of Biomedical Engineering in the Lampe Joint Department of Biomedical Engineering at North Carolina State University and the University of North Carolina at Chapel Hill. Brown notes that even incremental reductions in transfusion volume can matter for fragile patients weighing only a few kilograms.

What the preclinical data show so far

The early evidence for BK‑TriGs comes from controlled lab systems and animal models rather than human infants, but the signals are directionally consistent across platforms.

“We found that BK‑TriGs worked better at improving blood clotting in infant plasma than in adult plasma, which was what we expected to see,” says Brown. The microgel’s design is intended to exploit differences in infant clotting factor levels and kinetics rather than simply boosting coagulation indiscriminately.

“We found that the BK‑TriGs outperformed any of the other options we tested at reducing blood loss,” Brown adds. “Specifically, the BK‑TriGs reduced blood loss by 50-60% compared to the control group.” Those figures, while promising, come from tightly controlled experiments that cannot yet predict real‑world performance in the operating room.

Why infant clotting complicates the operating room

For surgeons and anesthesiologists, developmental differences in clotting are not just academic-they shape transfusion decisions, bypass protocols, and post‑operative monitoring. A technology that deliberately keys into infant physiology could eventually change those workflows if it proves safe and effective.

• Developmental hemostasis: newborns have a distinct balance of pro‑ and anticoagulant proteins and fibrinolytic activity compared with adults, yielding different clotting kinetics during and after surgery.
• Transfusion fit: operating rooms frequently rely on adult donor blood products, which can overshoot or undershoot the infant’s hemostatic needs and raise the risk of postoperative thrombosis or bleeding.
• Exposure risks: multiple product exposures (plasma, platelets, cryoprecipitate) increase complexity in dosing and monitoring during neonatal cardiothoracic and abdominal procedures.

Pediatric professional societies have for years urged more infant‑specific evidence to guide transfusion thresholds and use of hemostatic agents. Tools like BK‑TriGs, if validated, could give hospital transfusion committees another option beyond simply adjusting adult protocols down to infant size.

Safety signals that must be addressed before any clinical use

“The results we’re reporting here are exciting, but we are still far removed from clinical use,” says Brown. “We need to make sure there are no unforeseen risks associated with blood clotting.”

• Off‑target clotting and thrombosis: any pro‑hemostatic agent must demonstrate that it does not trigger pathologic clot formation in lungs, brain, or central lines, particularly in small‑caliber neonatal vessels.
• Biocompatibility and immunogenicity: materials testing typically includes sterility, pyrogenicity, hemolysis, complement activation, and assessments of immune sensitization.
• Dose finding in pediatrics: infant physiology constrains volume and dosing windows; scaling from adult paradigms is not appropriate.
• Interaction with standard care: compatibility with blood products, anticoagulation protocols during bypass, and point‑of‑care coagulation monitoring must be established.

Any signal of unanticipated clotting in preclinical models would likely trigger additional toxicology work and close scrutiny from hospital review boards before a first‑in‑infant study could proceed.

Regulatory pathway considerations in the United States

If BK‑TriGs advance toward human use, they will move into a regulatory environment that has become more attentive to pediatric devices and biologics, but still demands extensive safety data before testing products in newborns.

• Product classification: hemostatic technologies can be regulated as drugs, devices, biologics, or combination products; jurisdiction often depends on the product’s primary mode of action and may involve FDA centers overseeing biologics or devices.
• Pediatric development: pediatric assessments are a formal expectation for drugs and biologics, and dedicated pathways and consortia support pediatric devices to address historically limited availability of child‑specific technologies.
• Preclinical to first‑in‑human: typical steps include good laboratory practice (GLP) toxicology, thrombogenicity and embolic risk testing, manufacturing controls, and early feasibility protocols focused on safety and dose.

In the United States, any sponsor would ultimately need authorization from the U.S. Food and Drug Administration-most likely via an investigational new drug application or comparable investigational device exemption under the federal framework governing clinical trials-before BK‑TriGs could be tested in infants. Hospital institutional review boards would then decide how and where those trials could run, including which neonatal and cardiac surgery units participate.

Potential impact for hospitals and families if future trials succeed

For health systems, a successful infant‑tuned hemostatic product could have operational, financial, and policy repercussions, especially in high‑volume children’s hospitals that already manage strict blood‑use programs.

• Transfusion stewardship: a therapy tuned to infant clotting could reduce intraoperative bleeding and the volume of adult blood products used in neonatal cases.
• Operating room efficiency: fewer bleeding‑related interruptions can shorten bypass time or operative duration, with downstream effects on intensive‑care recovery and bed availability.
• Economic considerations: decreased reliance on multiple blood components and wastage could translate into cost offsets, provided acquisition costs and monitoring demands remain manageable.

For families, fewer transfusions and shorter postoperative stays are not only clinical outcomes but also emotional and financial ones, informing decisions about where complex neonatal surgery is sought and how payers design coverage for advanced hemostatic care.

“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.”

Equity and implementation questions that merit attention

As with many pediatric innovations, early adopters are likely to be large academic medical centers, raising questions about how quickly smaller hospitals can benefit if the technology is approved.

• Access across NICU levels: adoption would need to reach lower‑volume and rural hospitals that stabilize newborns before transfer to tertiary centers.
• Workforce readiness: perfusionists, anesthesiologists, and neonatal teams would require protocol training, including monitoring for thrombotic events and integration with point‑of‑care testing.
• Data transparency: pediatric trials benefit from harmonized endpoints for bleeding and thrombosis so results are comparable across institutions.

Health systems and professional societies would ultimately decide how BK‑TriGs, or similar products, are written into perioperative guidelines and quality metrics, shaping whether they become a niche tool or a standard part of neonatal surgical care.

Funding, affiliations, and disclosures

• Supported by the American Heart Association (22TPA969368), the National Science Foundation (2211404), and the Comparative Medicine Institute at North Carolina State University.
• Conflicts of interest: Brown is a co‑founder of Selsym Biotech, Inc., a company developing injectable materials intended to stop bleeding.

Standard conflict‑of‑interest and funding disclosures were reported in the journal publication; hospitals and regulators will weigh those relationships alongside independent replication of the findings.

Publication and institutional details

• Peer‑reviewed study in Science Advances published on April 3, 2026.
• Institutional announcement by North Carolina State University provides additional nonclinical context on materials design and testing methods; see the university release.

The combination of a high‑impact journal publication and institutional backing signals that BK‑TriGs will likely remain on the radar of pediatric surgeons, regulators, and health‑system leaders as the technology moves through the long, uncertain path from laboratory to operating room.