Embryonic stem cells overexpressing high molecular weight FGF2 isoform enhance recovery of pre-ganglionic spinal root lesion in combination with fibrin biopolymer mediated root repair

• hESCs overexpressing the 31 kD FGF2 isoform significantly enhance motoneuron survival and functional recovery after spinal root avulsion. • The combination of hESC therapy with heterologous fibrin biopolymer (HFB) provides a promising scaffold for cell delivery and root repair. • The 31 kD FGF2 isoform outperforms 18 and 23 kD isoforms in neuroprotection, immunomodulation, and attenuation of astrogliosis. • This approach offers a novel therapeutic strategy for preganglionic spinal root injuries, potentially improving quality of life and reducing treatment costs.