Laminin-Derived Peptides and Isoforms: A Multifaceted Review of Their Roles in Cancer, Neurodegeneration, Inflammation, Tissue Regeneration, and Exercise Physiology

Background: Laminins are heterotrimeric basement membrane glycoproteins whose chain composition, molecular processing, receptor engagement, and cellular source determine their biological effects. Methods: We conducted an integrative narrative search of PubMed and manually screened reference lists for studies of laminin isoforms, laminin-derived peptides, and polylaminin in cancer, neurological disorders, inflammation, tissue regeneration, wound healing, and exercise-related adaptation. Results: The evidence is heterogeneous and is predominantly mechanistic, in vitro, or preclinical. Laminin isoforms and derived peptides can produce opposing effects depending on the isoform or sequence, receptor, presentation format, tissue context, disease stage, and experimental model. Polylaminin is an experimental biomaterial with encouraging but preparation-dependent preclinical activity in selected neural repair models and in vitro stem cell culture. Conclusions: Laminin-based interventions should be developed in an indication-specific manner and require mechanistic validation, controlled delivery, dose–response characterization, safety assessment, reproducible manufacturing, and clinical validation before therapeutic translation.