Electrospinning Machine | Design and Development of Fiber Patch to Prevent Reperfusion Injury and Provide Thermal Stimulation for Treating Severe Frostbite

Frostbite is a common acute cold injury that can cause extensive tissue damage, often requiring amputation. However, most clinical interventions face the challenge of preventing or mitigating reperfusion injury while restoring blood supply.

Recently, Professor Zhou Shaobing's team at Southwest Jiaotong University developed a fiber patch with functions of preventing reperfusion injury and providing thermal stimulation for frostbite treatment. Itaconic acid (ITA) was embedded on the surface of necklace-like polymer fibers, optimizing its release kinetics and effectively inhibiting reactive oxygen species (ROS) production in the metabolic pathway. Local thermal stimulation from the fiber matrix regulates cytokine secretion and promotes microcirculation remodeling in frostbitten tissue. In a third-degree frostbite model study, the fiber patch showed superior therapeutic effects in accelerating tissue repair, outperforming conventional drug therapy. Therefore, this study provides a portable, effective, and preventive solution for frostbite management. The related research results were published in "Advanced Functional Materials" under the title "Design and Development of Fiber Patch to Prevent Reperfusion Injury and Provide Thermal Stimulation for Treating Severe Frostbite".

Figure 1 Schematic diagram of the preparation of the fiber patch and its therapeutic effect on frostbitten tissue.

As shown in Figure 1a, the fiber matrix for designing the patch consists of poly(lactic-co-glycolic acid) (PLGA) and gelatin-encapsulated polydopamine (PDA) particles. The discontinuous surface knots on the fiber surface consist of polyvinyl alcohol (PVA) and encapsulated itaconic acid (ITA). The high Laplace pressure difference (ΔP) and surface energy gradient (Fc) induced by PVA knots promote the absorption of exudate and subsequent ITA release (Figure 1b). Meanwhile, under red light irradiation, the PDA particles in the fiber matrix undergo photothermal conversion, raising the temperature of the frostbitten tissue to about 43°C, achieving rapid rewarming. The ITA released from the fiber patch binds to SDH in mitochondria, inhibiting succinate metabolism, thereby reducing intracellular ROS production after blood supply restoration. Experimental results show that micron-sized PDA particles can be retained within the frostbitten tissue, causing intratissue thermal stimulation. Local thermal stimulation upregulates the expression of heat shock protein-90 (HSP-90) and hypoxia-inducible factor-1α (HIF-1α) in frostbitten tissue, promoting angiogenesis and microcirculation remodeling by enhancing the expression and stability of vascular endothelial growth factor (VEGF).

Figure 2 Morphology and release performance characterization of fibers with necklace structure.

Figure 3 Portable fiber patch with necklace-like fibers and its surface properties.

Figure 4 Prevention of reperfusion injury and mitochondrial protection by the fiber patch.

Figure 5 Proliferation activity and tube formation of H/R model cells after applying the fiber patch.

Figure 6 Therapeutic effect of the fiber patch on frostbitten tissue.

Figure 7 Prevention of reperfusion injury and damaged tissue regeneration by the fiber patch.

Conclusion: This study developed a novel fiber patch capable of preventing reperfusion injury and providing thermal stimulation for treating frostbite. The necklace-like fibers within the fiber patch simultaneously encapsulate PDA and ITA. By optimizing PDA particle diameter and fiber surface characteristics, the rewarming effect was regulated and ITA release was controlled. The released ITA inhibits ROS generation by binding to succinate dehydrogenase, preventing reperfusion injury after rewarming through the metabolic pathway. Local thermal stimulation upregulates HSP-90 and HIF-1α in frostbitten tissue, enhancing VEGF expression and stability, promoting microcirculation reconstruction and collagen deposition, thereby accelerating tissue repair. The fiber patch developed in this study shows great potential as a portable, self-administerable frostbite treatment device.

Original link: https://doi.org/10.1002/adfm.202503172