By: IPP Bureau
Last updated : September 22, 2026 7:21 pm
Review highlights why getting medicines into the brain is only the first step
A multi-institutional review—co-authored by researchers from the Birla Institute of Technology and Science, Pilani (BITS Pilani) and institutions in Taiwan—reveals a critical bottleneck in neurological treatments. The study emphasizes that simply penetrating the blood-brain barrier is insufficient; ensuring a therapeutic agent successfully reaches its target and functions effectively within an aging brain remains a major hurdle.
According to a review published in the peer-reviewed journal Ageing Research Reviews, age-related alterations in the brain—including changes to blood flow, fluid dynamics, waste clearance, and immune response—significantly impact the pharmacokinetics of nanoparticles. These physiological changes ultimately alter how drug-delivery particles navigate the cerebral environment, their localization, and their overall therapeutic efficacy.
The review was undertaken by Ruei-Dun Teng, Jui-Ming Sun, Ting-Lin Yen, Cheng-Ta Hsieh, and Chih-Hao Yang from Taipei Medical University and affiliated institutions in Taiwan, with Dr. Rajeev Taliyan, Neuropsychopharmacology Division, Department of Pharmacy, BITS Pilani, India, as a collaborating author.
Dr. Rajeev Taliyan, Neuropsychopharmacology Division, Department of Pharmacy, BITS Pilani, Pilani Campus, Rajasthan, India, said, “Crossing the blood-brain barrier is only the first step in delivering medicines to the brain. As we age, the brain undergoes several changes that can affect how a medicine reaches its target and how well it works. Understanding these changes can help us develop better and more precise treatments for brain disorders.”
The review highlights that aging brains differ significantly from the young, healthy brains typically used in drug-delivery testing. Over time, blood vessels lose flexibility, the brain's waste-clearance system slows down, and immune shifts alter how nanoparticles behave. Consequently, a drug-delivery system that succeeds in youth may fail or function differently in older adults.
To overcome these challenges, the authors suggest developing drug-delivery systems that can respond to the changing conditions inside an aging brain. These systems may be developed to deliver drugs in response to specific modifications identified as a function of age and disease. The review also mentions that medicines can be given at an appropriate time of the day and that information about the patient can be used to decide on the most appropriate treatment.
The authors also highlight the importance of testing these drug delivery systems in more advanced and realistic biological systems before they are applied to patients. Knowing how the nanoparticles behave in the blood and brain of older individuals may help make the nanoparticles safer and more effective.
The review calls for a change in how brain-targeted medicines are developed. Instead of focusing only on whether a medicine can cross the blood-brain barrier, researchers should also understand what happens to it after it enters the brain. This approach could help in developing safer and more effective treatments for age-related brain conditions, including Alzheimer’s and Parkinson’s diseases.