Brain Diseases’ Worst Enemy: Nanoparticles

Understanding Nanotechnology through Targeted Drug Delivery to the Brain

Therefore, by definition, Nanotechnology is the control and fabrication of matter at the nanoscale.

To put things in perspective, consider one of the smallest things we can see with the naked eye: a single human hair. Now here is where it gets really crazy. A single human hair is around 90,000 nanometers wide.

A Nanowire (highlighted in red) curled in a loop on a single human hair. Source


Nanoparticles are one of the main aspects of nanotechnology. They are particles of matter with at least one dimension in the nanoscale.


The Magic School Bus in Real Life

Remember the classic TV show The Magic School Bus, where the teacher and her class would go on the school bus, it would shrink down and then travel throughout the body? Targeted drug delivery is essentially that, except instead of students, there are drugs or medication

Targeted Drug Delivery is a group of technologies that deliver and control the release of drugs to very specific parts of the body.

The way they work is by using nanoparticles, or other materials at the nanoscale, to bind to certain target receptors found in the specific cells.

Why Nanotechnology?

The blood-brain barrier (BBB) is a highly selective semipermeable membrane whose job is to stop substances in the blood from entering the central nervous system and coming into contact with neurons.

A simplified makeup of the blood-brain barrier. Source
  1. Passive Delivery
  2. Temporary Disruption of the BBB
  3. Active Delivery

Blowing Chemotherapy Out of the Water

Through the introduction of multifunctional nanoparticles into targeted drug delivery, it has been able to overcome one of the biggest challenges with chemotherapy: systemic toxicity.

An example of a multifunctional nanoparticle. Source

Polymeric Nanospheres and Nanocapsules:

Nanospheres and nanocapsules are two similar types of nanoparticles.


Polymeric Nanogels and Nanosuspensions:

Nanogels are a network of physically or chemically linked polymers. Nanosuspensions is the process in which the drugs are colloidally (evenly) in the nanogel.


Polymeric Nanomicelles:

Nanomicelles are, by far, the most unique nanoparticles out there, due to their structure. Polymeric Nanomicells are types of nanoparticles in which all of their benefits lie in said structure.


Polymeric Nanoliposomes:

Nanoliposomes are the fan-favourite nanoparticles for targeted drug delivery. They are vesicles that are made of singular (or occasionally multiple) lipid bilayers, surrounding an aqueous core. A lipid bilayer is a membrane of 2 lipid molecules, surrounding a watery core. The drugs are added to the core.



Dendrimers are spherical nanoparticles that are made up of repetitive tree-like structures, that stem from a singular core or multiple cores. The core is the central part to which all the primary levels of branches are connected to. The primary branches then split in the shell, then the split branches split again, and so on. The final layer consists of the terminal branches. The unique branching structure allows for the encapsulation of drugs.


Iron Oxide Nanoparticles:

Targeted Drug Delivery in the brain has also been accomplished using magnetic nanoparticles, made out of iron oxide.



To summarize, various types of nanoparticles can be and are being used to find more efficient methods to work around the challenges and deliver drugs into one of the most difficult places in our body, the brain.



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Aahaan Maini

16-year-old ML dev currently building Circulate to tackle the blood shortage in India