Scientists in Italy have reported promising results from an experimental nasal spray treatment for Alzheimer’s disease utilizing tiny, naturally released packages derived from human placental cells, according to findings published in the journal Translational Neurodegeneration. The research brings together investigations into the regenerative properties of the placenta and the role of brain inflammation in neurodegenerative conditions.
Placenta-Derived Nasal Spray Shows Memory-Protecting Promise in Alzheimer’s Mouse Study
While the hallmark features of Alzheimer’s disease include sticky proteins known as amyloid-beta and tau, researchers increasingly recognize that chronic activation of brain cells such as microglia and astrocytes leads to harmful neuroinflammation. To counter this, a research team utilized human amniotic mesenchymal stromal cell-derived vesicles (hAMSC-EVs) sourced from the placental amniotic membrane, according to Knowridge.
Experimental Testing and Delivery to the Brain
The experimental formulation was administered intranasally as a spray to transgenic mice genetically engineered to develop features of Alzheimer’s disease. The animals received doses twice a week for six months, starting at three months of age before symptoms manifested and continuing until nine months of age, as reported by Sciencealert.
Fluorescent dye tests confirmed that the extracellular vesicles successfully traveled through the nose and reached all regions of the hippocampus—a brain area essential for learning and memory that is affected early in Alzheimer’s. Once there, the vesicles co-localized with both neurons and microglia. Behavioral testing demonstrated that the treated mice exhibited improved cognitive performance compared to control animals in tasks measuring object recognition, spatial memory, and short-term working memory.
Combating Neuroinflammation and Protecting Synapses
The treatment operated by reshaping the inflammatory microenvironment rather than directly shutting down the immune response. According to Jiji Press, the extracellular vesicles modified the functional state and morphology of microglia to create favorable conditions for maintaining neuronal integrity. Furthermore, the therapy reduced neuronal deterioration and significantly increased levels of proteins linked to neuronal plasticity, synaptic transmission efficiency, and memory processes.
Importantly, researchers observed that the vesicles were able both to prevent the onset of memory deficits when administered earlier and to reduce cognitive decline after problems had already developed. The treatment also significantly reduced amyloid-beta deposits in the hippocampus.
Testing on Human Neurons and Collaborative Research
To investigate whether the findings applied to humans, researchers at the Gemelli Memory Clinic collected skin samples from Alzheimer’s patients and healthy volunteers. These cells were reprogrammed into stem cells and developed into neurons in the laboratory. The vesicles produced protective changes in these human neurons in vitro, providing additional support for the approach.
The study was conducted by teams from the Università Cattolica del Sacro Cuore, Fondazione Policlinico Universitario A. Gemelli IRCCS, and the E. Menni Research Center of Fondazione Poliambulanza. Key contributors to the project include first author and cell biologist Andrea Papait, Francesca Natale, Ornella Parolini, Claudio Grassi, and Salvatore Fusco.