Title: Drug-delivering particles aim to breach the blood–brain barrier
URL Source: https://www.nature.com/articles/d41586-026-02655-6
Markdown Content:
• OUTLOOK
• 09 September 2026
The inability to get drugs into the brain has impeded the treatment of cancer and neurodegenerative diseases for decades. Techniques based on nanoparticles and exosomes are vying to provide a solution.
By
• [Simon Makin](https://www.nature.com/articles/d41586-026-02655-6#author-0)[0](https://www.nature.com/articles/d41586-026-02655-6#Aff0)
• Simon Makin
• Simon Makin is a freelance writer in Reading, UK.

Illustration: Julia Specht represented by Roar Artists
The most formidable barrier in medicine is the one that separates the brain from the bloodstream. Some small, simple chemical compounds such as paracetamol can cross the blood–brain barrier, but for larger molecules, such as proteins and messenger RNA, it is completely impermeable. There is a good reason for this — toxins and pathogens swimming in the blood could wreak havoc in the brain. But the barrier also makes it difficult to treat the devastating diseases that affect this delicate organ.
_Nature_**657**, S4-S7 (2026)
_doi: https://doi.org/10.1038/d41586-026-02655-6_
This article is part of [Nature Outlook: Drug delivery](https://www.nature.com/collections/jggjicdegi), a supplement produced with financial support from [Taiho Oncology, Inc](https://www.taihooncology.com/us/). _Nature_ maintains full independence in all editorial decisions related to the content. [About this content](https://partnerships.nature.com/commercial-content-at-nature-research/).
References
• Wang, C. _et al._ _Nature Mater._**24**, 1653–1663 (2025).
[Article](https://doi.org/10.1038%2Fs41563-024-02114-5)[PubMed](http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Abstract&list_uids=39962245)[Google Scholar](http://scholar.google.com/scholar_lookup?&title=&journal=Nature%20Mater.&doi=10.1038%2Fs41563-024-02114-5&volume=24&pages=1653-1663&publication_year=2025&author=Wang%2CC.)
• Martins, C. _et al._ _Small_**19**, 2300029 (2023).
[Article](https://doi.org/10.1002%2Fsmll.202300029)[Google Scholar](http://scholar.google.com/scholar_lookup?&title=&journal=Small&doi=10.1002%2Fsmll.202300029&volume=19&publication_year=2023&author=Martins%2CC.)
• Yang, Z. _et al._ _Nature Biomed. Eng._**4**, 69–83 (2020).
[Article](https://doi.org/10.1038%2Fs41551-019-0485-1)[PubMed](http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Abstract&list_uids=31844155)[Google Scholar](http://scholar.google.com/scholar_lookup?&title=&journal=Nature%20Biomed.%20Eng.&doi=10.1038%2Fs41551-019-0485-1&volume=4&pages=69-83&publication_year=2020&author=Yang%2CZ.)
[Download references](https://citation-needed.springer.com/v2/references/10.1038/d41586-026-02655-6?format=refman&flavour=references)
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Can this work for large proteins too? Most current methods only handle small molecules or mRNA effectively.
The Trojan horse analogy is perfect here. It is exciting to see biology outsmarting its own defenses.
What about immune system recognition? These foreign particles could trigger inflammation before they even reach the brain.
I worry about long-term toxicity. Can we be sure these particles clear safely from neural tissue after delivering their payload?
Finally! Decades of frustration for Alzheimer’s researchers might actually be over with these new nanoparticle approaches.