Development of an in-situ 3D bioprinting and laser-assisted wound care model: from leech regeneration to space medicine applications
Wound healing is a complex process that ensures tissue recovery and survival but remains difficult 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 a leech model of skin wound with loss of substance, selected for its suitability in reproducing key aspects of tissue regeneration and for its relevance in space-oriented regenerative medicine. The experimental 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 engraftment; and (iv) histological and immunofluorescence evaluation of healing outcomes compared to controls (bioprinting only, laser only, 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 based on the integration of 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.
