Matrix-free cryo-microneedles array patch for 3D hair follicle organoids delivery and rapid hair regeneration.

Hair follicle (HF) organoid transplantation has emerged as a significant advancement for hair regeneration and wound repair. This study developed an efficient and minimally invasive cryo-microneedles array patch (cryo-MAP) technique to transplant self-assembled 3D HF organoids from matrix-free, serum-free culture and low-DMSO cryopreservation. This method successfully avoids the growth suppression caused by hydrogels, allowing HFs to germinate within 3 days. Furthermore, proteomics confirmed that cryopreservation not only maintained high cell viability but also enhanced the organoids' capacity for directional differentiation. The transplanted organoids regenerated complex skin structures, achieving successful hair growth penetrating the skin in approximately 15 days with an over 86% success rate. These results open up new possibilities for organoid transplantation platforms in the fields of tissue engineering and regenerative medicine.