Substance‐P and transforming growth factor‐β in chitosan microparticle‐pluronic hydrogel accelerates regenerative wound repair of skin injury by local ionizing radiation

: Clinical irradiation therapy for cancer could increase the risk of localized wound complications. This study was conducted to evaluate the potential use of a chitosan microparticle-pluronic F127 (CSMP-PF) hydrogel complex containing bioactive molecules, substance P and transforming growth factor-β1, to regeneratively repair skin damaged by local ionizing radiation (IR). The BALB/c/bkl mice were locally irradiated to their limbs with a single 40 Gy dose of Co-60 γ rays to induce a skin injury. The morphological characteristics of the chitosan microparticles were analysed by scanning electron microscopy. The amounts of bioactive molecules taken up and released by the CSMP-PF hydrogel complex were measured. Haematoxylin and eosin staining of IR-damaged skin showed acanthosis and hyperkeratosis in the epidermis; and damage to hair follicles/skin appendages and adipose tissue, as well as panniculus carnosus, in the dermis. Injection of the CSMP-PF hydrogel complex into IR-damaged skin resulted in skin repair, suggesting that the complex has potential for use in the regenerative repair of IR-damaged skin.