Inclusion criteria:
• Definite diagnosis of Alzheimer's disease based on DSM-5 criteria and confirmed by brain scans (MRI). • Definite diagnosis of mild or moderate Alzheimer's disease based on NIA/AA (2018) criteria. • Patients must have a low to moderate score (usually between 20 and 35) on the QoL-AD test, which indicates a decrease in quality of life due to the disease. • Patients must have an ADAS-Cog score in the range of early to moderate Alzheimer's disease (usually between 15 and 40). • MMSE score between 10 and 24 (inclusive). • Score less than or equal to 4 on the Modified Hashinsky Ischemic Scale (MHIS). • Age between 55 and 80 years. • Body mass index (BMI) between 18.5 and 30. • Written informed consent obtained from the patient and legal representative or close family before the study began. • The patient's general condition is appropriate based on medical history, physical examination, vital signs, laboratory tests, and electrocardiogram (ECG) results. • Ability to walk independently or with assistive devices (such as a wheelchair, walker, or cane) and no vision or hearing problems that would prevent them from following the study (using glasses or hearing aids is permitted). • Presence of a designated and reliable caregiver who meets the following requirements: o Ability to read and understand research-related documents and communicate with the investigator. o Ability to follow research instructions and provide accurate information about the patient's condition during the study. o Living with the patient or providing care at least 3 days a week and at least 2 hours a day.
Exclusion criteria:
• Non-cooperation during the study. • Serious treatment-related adverse events. • Active infectious diseases or autoimmune disorders. • Severe hypersensitivity to therapeutic compounds. • Receiving treatment with mesenchymal stem cells or their derived exosomes. • The following laboratory results: o Neutrophil count less than 100 × 10⁹/L o Platelet count less than 100 × 10⁹/L o Serum albumin level less than 30 g/L. o Serum creatinine level above the normal range. o Total bilirubin, ALT, and AST levels greater than twice the upper limit of normal. • Underlying medical conditions, including (but not limited to) cardiovascular, cerebrovascular, hepatic, renal, pulmonary, or endocrine diseases. • Severe Alzheimer’s. (Score less than 10 on MMSE and MoCA questionnaires) • Severe depression (score greater than 29 on standard questionnaires such as Beck Depression Inventory (BDI-II) or score 24–35 on the 24-item version of the Hamilton Depression Scale (HAM-D)). • Having diseases such as Parkinson's, vascular dementia, Huntington's, hydrocephalus, progressive supranuclear palsy, multiple sclerosis, epilepsy, mental retardation, or a significant history of brain injury. • Having a history of malignant neoplasm. • Contraindications to MRI for reasons such as the presence of implanted electronic devices, agoraphobia, or critical condition. • Positive results for HIV, HBV, HCV, and syphilis. • Participation in another clinical study in the past 6 months. • Pregnancy, breastfeeding, or pregnancy in the past 6 months. • Any other conditions that the investigator deems inappropriate, including factors that reduce compliance with follow-up.