Penn State Engineers Build Tunable Foam-Like Biomaterial That Speeds Blood Vessel Growth in Wounds

Penn State

The problem with most biomaterials designed for wound healing is not that they fail entirely. It is that physicians cannot control what happens inside them at the cellular level. The pores that allow oxygen, nutrients, and cells to reach damaged tissue are formed somewhat haphazardly, and their size and connectivity, the very features that determine whether new blood vessels can grow through the material, are difficult to engineer precisely.

A team at Penn State has addressed this with a new approach: building scaffolds not from a continuous material but from precisely sized building blocks that self-assemble into a structure with programmable internal architecture.

Aerogels: mostly air, by design

Aerogels are ultralight materials composed primarily of air, with enormous internal surface area relative to their mass. That makes them attractive for tissue regeneration: the open, porous structure can store and transport cells while allowing efficient movement of oxygen and nutrients. But traditional aerogels offer limited control over pore architecture at the scale that cells actually operate on, roughly tens to hundreds of micrometers.

Amir Sheikhi, the study's corresponding author and an associate professor of chemical engineering at Penn State, developed what the team calls granular aerogel scaffolds (GAS). Instead of forming aerogels through conventional chemistry, they assemble them from size-controlled, protein-based microparticles. By changing the size of these building blocks, the researchers can program the pore geometry and interconnectivity of the resulting scaffold without altering its mechanical properties.

"By changing the size of these building blocks, we can program the pore geometry and interconnectivity of the scaffold," Sheikhi explained. "This allows us to adjust pore size without impacting the material's stiffness and avoid structural collapse during drying, limitations that have historically constrained aerogel performance in regenerative medicine."

Testing in tubes and in mice

The team tested GAS both in vitro (in laboratory cell cultures) and in vivo (in mouse models). The results, published in Biomaterials, showed that the tunable pore architecture made a measurable difference. Scaffolds with optimized pore sizes showed improved cell infiltration and, critically, faster formation of new blood vessels compared to conventional aerogel structures.

Dino Ravnic, a professor of surgery and co-author on the paper, emphasized why vascularization matters: "To be clinically useful for tissue repair, biomaterials must undergo cell infiltration and vascularization upon implantation. If vascularization cannot occur with the material present, tissue repair is not possible, which can lead to patient disease, reoperation and increased health care costs."

This is especially problematic in wounds with compromised blood supply at baseline: irradiated tissue, diabetic wounds, and burn injuries. These patients currently have limited treatment options because their wounds lack the vascular capacity to support conventional biomaterial implants.

Engineering guided by surgery

The project represents a deliberate collaboration between engineers and clinicians. Sheikhi's lab identified the pore-control problem and invented the GAS approach. Ravnic's surgical team then helped optimize the material for biological performance, providing feedback on what properties matter most for clinical utility: rapid vascular ingrowth, mechanical stability during handling, and compatibility with surgical implantation techniques.

"Engineers can design materials with almost any property, but clinical insight allows us to optimize for practical use," Sheikhi said. The feedback loop between laboratory testing and surgical assessment shaped the material's development at each stage.

Shelf stability and commercial potential

One practical advantage of GAS that the researchers highlight is shelf stability. The material can be dried, sterilized, stored at room temperature, and rapidly rehydrated without losing its pore architecture or mechanical properties. For a biomaterial aiming at clinical translation, this matters enormously. A product that requires cold storage, special handling, or immediate use after fabrication faces much higher logistical barriers to adoption than one that can sit on a shelf.

The team is actively exploring paths toward commercialization, including patent filings and industry partnerships. The immediate next steps involve adding biochemical cues to the scaffold, factors that promote cell growth or modulate immune responses, to enhance the platform's therapeutic activity beyond its structural role.

What remains to be demonstrated

The current work is preclinical. The mouse model results are promising, but mouse skin wounds heal differently from human wounds in important ways, including faster closure, different immune responses, and the presence of a contractile muscle layer (panniculus carnosus) that humans lack. Translating pore-optimization benefits observed in mice to human wound healing will require larger animal studies and eventually clinical trials.

The study demonstrates proof of concept for tunable pore architecture and its effect on vascularization, but it does not address long-term outcomes: how the material degrades over weeks to months, whether the new blood vessels persist and mature, and whether the healed tissue achieves functional equivalence to uninjured tissue. These are standard gaps in early-stage biomaterials research, but they represent significant distance between current results and clinical utility.

The biomaterials field has a long history of promising preclinical results that struggle to clear the translational hurdle. GAS may prove to be an exception, but the path from a successful mouse study to an FDA-approved wound care product typically spans a decade or more.

For reconstructive surgeons treating patients with tissue loss from burns, radiation, diabetes, or trauma, a platform biomaterial that promotes reliable vascularization would address a genuine unmet need. Whether GAS can deliver on that promise will depend on the work that comes next.