The Role of Nanorobots in Drug Delivery

Usually, people treat diseases by taking a pill that dissolves and diffuses slowly, but this method often has adverse side effects. Fortunately, nanoscale robots have emerged as a better alternative since they target diseases directly. Could they be the future of drug delivery?

What Are Drug Delivery Nanorobots?

In drug delivery, nanoscale robots (nanorobots) are designed to access hard-to-reach areas of the human body to administer medication at a microscopic level. These machines range in size from 1–100 nanometers, which is where they get their name. To put those figures into perspective, one meter is equivalent to 1,000,000,000 nanometers.

Nanorobots are either autonomous or remotely controlled. Unlike traditional drugs — which are orally administered and passively dispersed once in the body — they actively navigate toward the disease’s source. There, they deliver the drug directly.

The benefit of targeting diseases at their source is it minimizes adverse side effects. For example, cancer treatments often make people sick because they target non-specific areas. Unfortunately, radiation is just as toxic to regular cells as it is to cancerous ones.

Considering about 50% of cancer patients receive radiation therapy, the health care sector has searched for an alternative for ages. With nanorobots, medical professionals can zero in on tumors directly instead of targeting large sections of a person’s body. This way, they experience little to no adverse side effects — and their treatment is more effective.

While health care nanorobotics seems futuristic, the technology already exists. The United States Food and Drug Administration (FDA) has already approved nanotechnology, including nanocarriers and nanocarrier-based drugs. 

The Drug Delivery Techniques Nanobots Use

Nanorobots can deliver drugs in one of several ways, each with unique benefits and challenges. Researchers are constantly uncovering new methods, so here are some of the most common.

Chemical

Chemically driven nanorobots convert chemical energy into kinetic energy to propel themselves toward their destination. The human body runs on chemical energy, so there’s plenty around to supply these machines.

Artificial Intelligence

Artificial intelligence is one of the latest developments in nanorobotics. With this technology, the robots autonomously propel themselves toward their target. Robotic AI is far more precise than humans, so this progression was a matter of time.

These algorithms already exist. For example, researchers developed a model that can predict drugs’ therapeutic effects by analyzing cell images. Since people have unique molecular profiles and different disease biomarkers, utilizing AI to tailor dosages and treatments is ideal.

Biological

Biologically driven nanorobots combine live microorganisms — like bacteria or sperm, for example — with synthetic materials. They use biological reactions to propel themselves toward their destination.

Magnetic

Nanorobots coated or embedded with magnetic nanoparticles rely on external forces to move. Medical professionals must adjust the magnetic field’s direction or intensity from outside the body to direct the machines toward the disease’s source.

So far, this drug delivery technique is among the most commonly studied because it’s effective despite its simplicity. In fact, studies show magnetic nanocarriers improve tumor treatment efficacy by 20% compared to their passive counterparts.

Ultrasound 

Sound waves can travel through solids, liquids or gases, so they can deeply penetrate body tissues easily. Medical professionals can use ultrasound to propel their nanorobots toward their destination without causing noticeable harm to the patient.

How Do These Nanobots Work?

Nanobots travel through blood vessels, so they have to be soft-bodied and flexible. Since they enter the tissue, they have to be biocompatible, meaning they can’t damage living matter. Engineers must consider those conditions when selecting materials. While some opt for purely synthetic designs, others choose a combination of biological and inorganic.

Propulsion is complicated. Engineers must work out how to guide nanorobots with little to no communication. While the concept — either magnetic, AI, biological, chemical or ultrasound delivery — is well-researched, figuring out the mechanical aspect can be challenging since they have little room for intricate technical feats at the nanoscale.

A variety of monitoring solutions exist. Medical professionals can use photoacoustic, fluorescent or magnetic imaging techniques to track nanoscale machines as they move through a patient’s body. One proof-of-concept involves biomolecular communication, where a machine interprets molecules in the bloodstream as either a one or a zero, meaning in binary.

So far, most nanorobotics applications use swarms — hundreds or hundreds of thousands of nanoparticles — because monitoring a single object smaller than a red blood cell as it travels through the body would be technically and logistically impossible. Also, having larger groups means the robots can carry a large enough dose for treatment.

How Do Nanobots Deliver Drugs?

In principle, nanorobots must be orally ingested or administered through a syringe to enter a patient's body. Once inside, they need to make their way to their target. Professionals use their chosen propulsion, monitoring, and imaging techniques to guide and monitor them.

While the nanobots are en route to their destination, they have to protect their payload. Many have a special coating or capsule to prevent the drug from being accidentally delivered elsewhere.

When these machines finish their task, they must be retrieved, dissolved or expelled. If they degrade, they must be biodegradable and non-toxic. If the patient has to expel them, they must all be accounted for. Managing this hurdle is one of the most significant robotics engineers and researchers face.

How Are Nanobots Used in Drug Delivery?

Although nanotechnology has FDA approval, the health care industry isn’t using it for drug delivery quite yet. This technology is largely still in the development phase. While several nanocarrier-based drugs are on the market already, these nanoscale machines are still stuck in clinical trials.

The hesitancy makes sense since researchers and robotics engineers must overcome a few hurdles before moving on to mass-market production. For one, once they figure out a practical, foolproof drug delivery technique, they must figure out how to remove their machines from inside patients’ bodies quickly and safely.

Another significant obstacle is standardization. While it’s great that researchers have developed numerous drug delivery, design, communication and monitoring methods, the current approach seems to be exploring potential solutions instead of refining existing ones. As long as this continues, progress may stagnate.

The Future of Nanoscale Drug Delivery 

Drug delivery nanorobotics could be incredibly promising for patients and providers. If researchers and engineers can develop safe, effective robots, they could revolutionize drug delivery. This technology promises a future where cancer patients don’t have to get sick during treatment and where sick people can get better exponentially faster.