Development of an in situ 3D bioprinting and laser-assisted wound care model: From leech regeneration to space medicine applications

G. Loi, M. Zaccara, F. Cialdai, C. Risaliti, G. Leggieri, L. Notari, D. Bani, M. Conti, M. Monici
International Journal of Bioprinting, 12(1), 2026

Wound healing is a complex process that ensures tissue recovery and survival, but remains challenging to manage, particularly in deep wounds and burns. Conventional treatments require specialized operators, repeated interventions, and high costs. In extreme environments, such as space, the absence of dedicated facilities and personnel further complicates wound care, highlighting the need for novel, automated, and easy-to-use therapeutic strategies. In this study, we developed and validated a protocol that combines in situ 3D bioprinting with near-infrared (NIR) laser irradiation to promote graft integration and accelerate wound repair. The approach was tested in the leech model of a skin wound with tissue loss, selected for its suitability in reproducing key aspects of tissue regeneration and for its relevance in space-oriented regenerative medicine experiments design comprised four steps: (i) identification of biomaterial inks compatible with the wound environment; (ii) application of an optimized in situ 3D bioprinting protocol; (iii) NIR laser irradiation to stimulate graft integration; and (iv) histological and immunofluorescence evaluation of healing outcomes compared to controls (bioprinting only, laser only, and untreated). Results demonstrated that the integrated protocol significantly improved wound healing, preventing fibrosis and enhancing re-epithelialization, fibroblast activation, and transdifferentiation. The combined treatment outperformed all control conditions, confirming the synergistic effect of In situ bioprinting and laser irradiation. This work introduces an advanced wound care strategy integrating biofabrication and photobiomodulation. The protocol shows high potential for clinical translation, with applications not only in conventional medical settings but also in extreme environments such as space.