Cell-based regenerative interventions in Parkinson's disease: Overcoming pharmacological limitations

Parkinson's disease (PD) is a progressive neurodegenerative disorder characterized by the loss of dopaminergic (DA) neurons and the pathological aggregation of α-synuclein. While current pharmacological therapies provide symptomatic relief, they do not halt or reverse disease progression. Cell-based regenerative strategies have emerged as promising approaches to restore DA function and target the complex, multifactorial pathophysiology of PD. This review critically examines current approaches, including transplantation of fetal ventral mesencephalic tissue, pluripotent stem cell-derived midbrain DA progenitors, and in vivo reprogramming of endogenous cells. In addition, supportive cell types, such as mesenchymal stromal cells and carotid body glomus cells, provide neuroprotective and immunomodulatory effects via paracrine signaling. We summarize preclinical and clinical evidence on graft survival, integration, and functional recovery, and discuss key determinants of therapeutic efficacy, including mitochondrial function and bioenergetic integrity, immune compatibility, and biomaterial scaffolding. Despite significant progress, major challenges remain regarding long-term efficacy, graft standardization, and host-graft interactions. Ongoing translational advances are poised to drive the development of disease-modifying cell therapies capable of delivering durable clinical benefits and improving long-term outcomes in PD.