Microneedle arrays for brain drug delivery: the potential of additive manufacturing

For a long time, the treatment of brain diseases has been a significant challenge. Drug delivery to the brain has recently become one of the most challenging problems for patients with severe forms of central nervous system diseases. The blood–brain barrier (BBB) poses a significant challenge for drug delivery to the brain. While extensive efforts focus on finding materials to overcome the BBB for brain tumor treatment, it limits the penetration of chemotherapeutic drugs for the broader treatment of brain diseases. The oral method of drug administration has several drawbacks, such as the loss of drugs because of metabolism and gastrointestinal environmental issues. Besides, using the intravenous route to administer medicines has several disadvantages, including discomfort at the injection site, infection, bleeding, anxiety, and incompetence toward patients. Fabrication and development of microneedles to overcome the drawbacks mentioned above of traditional drug delivery methods may be a viable alternative. Drug delivery using microneedle arrays (MNAs) has recently been shown to be an effective method for delivering drugs to the brain. Different fabricating methods like three-dimensional printing could be used for the fabrication of personalized drug delivery systems, like MNAs, with precise control over spatiotemporal drug distribution. This article presents a review of using MNAs for drug delivery to the brain.