Wound-healing scaffold expands its pores by 91%, promoting healing in mice

Anyone who has had a wound treated knows the pain of removing gauze only to have newly formed tissue pulled away with it, reopening the wound. A self-adjusting wound-healing scaffold that could address this problem has been developed.

According to the international journal Journal of Functional Biomaterials (J Funct Biomater) on the 28th, a research team including Krete Medical reported findings from a study in which it designed an electrospun scaffold made from three components to support wound healing.

The scaffold’s key feature is that its three materials are designed to degrade at different rates. One component dissolves as soon as it comes into contact with water, helping the scaffold conform to the skin. Another breaks down through hydrolysis within days, gradually widening the spaces between fibers. The third degrades most slowly, supporting the overall structure until the first two components have completed their roles.

This is similar to erecting a temporary stage. Some support posts are removed after a few days to clear space, while a few sturdy posts remain until the performance ends and are taken down last. Rather than waiting for the material to collapse on its own, the scaffold actively changes its structure in step with tissue growth.

Experimental results supported this design. On day 7 of in vitro culture, the scaffold’s maximum pore size increased by 91%, from 80.4 micrometers to 153.6 micrometers. This falls within the 100-200 micrometer range known to allow fibroblasts to move freely.

The research team confirmed the effect of pore expansion in a predegradation control experiment. After immersing the scaffold in cell-free culture medium for 7 days to sufficiently widen its pores, the team seeded fibroblasts onto it; the cells spread out from the first day. By contrast, cells cultured on a new scaffold took 3 days to reach the same state. This indicates that the cells’ spreading was driven by the enlarged pores, rather than by their adaptation to the culture medium.

The animal experiment showed a more pronounced difference. In a full-thickness skin-defect model on the backs of mice, the wound-healing rate in the scaffold group began to exceed that in the petrolatum-gauze group on day 7. The gap was greatest on day 14, and the scaffold group maintained a significant advantage on day 21.

By day 28, both groups appeared almost fully healed to the naked eye, but quantitative microscopic analysis of collagen revealed a difference. The collagen area fraction remained at 45.4% in the scaffold group, while it was only 30.6% in the control group. The favorable environment provided early on appears to have helped newly formed collagen tissue better withstand the later remodeling process.

Safety was also assessed. No foreign-body giant cells or fibrous capsules were observed, and the scaffold group had a lower inflammation score on day 7. The two groups showed similar levels thereafter. The animals gained weight normally, and no signs of toxicity were observed.

The design principle behind the scaffold is simple: rather than having a single material perform every role from beginning to end, it divides the needs over time so that multiple components take over in sequence. A product using this structure has already received U.S. Food and Drug Administration (FDA) 510(k) clearance.

The research team said it will be important to see how the scaffold performs in various types of wounds, including diabetic foot ulcers and burns. There is interest in whether the painful experience that has repeatedly accompanied wound treatment could soon become a thing of the past.