Engineered human myogenic cells in hydrogels generate functional myofibers within dystrophic mouse muscle

Transplantation of human myogenic progenitor cells (MPCs) is a promising therapeutic strategy for treating muscle-wasting diseases, e.g., Duchenne muscular dystrophy (DMD). To increase engraftment efficiency of donor stem cells, modulation of host muscles is required, significantly limiting their clinical translation. Here we develop a clinically relevant transplantation strategy synergising hydrogel-mediated delivery and engineered human MPCs generated from CRISPR-corrected DMD patient-derived pluripotent stem cells (PSCs). We demonstrate that donor-derived human myofibers produce full-length dystrophin at 4 weeks and 5 - 6 months (long-term) post transplantation in the unmodulated muscles of the dystrophin-deficient mouse model of DMD. Remarkably, human myofibers are innervated by mouse motor neurons forming neuromuscular junctions and supported by vascularisation after long-term engraftment in dystrophic mice. PAX7+ cells of human origin replenish the satellite cell niche. There was no evidence of tumorigenesis in mice engrafted with hydrogel-encapsulated human MPCs. Our results provide a proof-of-concept in developing hydrogel-based cell therapy for muscle-wasting diseases.