RecruitingDrug trialExploring Nasal Drop Therapy With Small Extracellular Vesicles for ALSThis is a multicenter, randomized, double-blind, placebo-controlled, dose-escalation trial. The goal of this clinical trial is to evaluate the safety and preliminary efficacy of nasal drop exosomes derived from human umbilical cord blood mesenchymal stem cells (hUC-MSC-sEV-001) in amyotrophic lateral sclerosis.