Facing The Truth About Nanotechnology in Drug Delivery

Why Do Scientists Do What They Do?  

Scientists and engineers do what they do because they genuinely enjoy it. When it comes to nanotechnology, it’s not enough to just make something tiny and complex. The real purpose-especially in drug delivery is to create systems that help prevent, manage, or treat serious illnesses. Researchers in medicine and biotech are working hard to design tiny particles that can carry medicine directly to the right part of the body, making treatments more effective and reducing side effects. [1] [2]

There are still many health problems that need better solutions. For example, people with diabetes still have to prick their fingers and inject insulin several times a day. Could nanotech make this easier? Heart disease is the top cause of death in the U.S.-can nanotech help reduce that? Alzheimer’s affects not just patients but their loved ones too. Could it be detected earlier and treated better with nanotech? What about the misuse of prescription painkillers-could nanotech help make safer versions? And cancer takes millions of lives every year-can nanotech help stop it? 

Despite all the excitement around nanotechnology, it hasn’t yet delivered major breakthroughs for these problems [3]. In fact, some studies seem to focus more on making things complicated than actually solving real issues. That’s why it’s important for scientists to stay focused on meaningful goals are not just making things smaller, but making things better. 

What is Nanotechnology in Drug Delivery?  

In drug delivery research, a lot of attention has been given to using nanotechnology to target tumors. This area is often used to measure how far nanotech has come in the past ten years. Two commonly mentioned examples are Doxil and Abraxane [4] [5]. They’re considered nanotech based because they’re tiny-measured in nanometers. 

Doxil, a type of liposome coated with a substance called PEG, was developed back in the 1980s and approved by the FDA in 1995 [4]. It worked just as well as regular doxorubicin but was safer for the heart. That’s one way nanotech has lived up to its promise: delivering drugs more precisely with fewer side effects.

Table 1. FDA approved nano-technology based drug products

However, liposomes have been around for 60 years, and PEGylation for 40 [4] [6]. Abraxane is made using a basic oil-and-water mixture [5]. The process involves dissolving the drug paclitaxel in a chemical, mixing it with albumin (a protein), and then turning it into tiny droplets. These droplets are dried to form nanoparticles. You can also make similar particles by simply grinding the drug with albumin.

Even though Doxil and Abraxane are nanosized, they weren’t created using modern nanotech ideas. They were made using older, well-known methods. So, the question is: should we call something nanotechnology just because it’s small? If that’s the case, then today’s “nanotech” in drug delivery might just be a new label on old techniques-with no real innovation [3]. 

Figure 1. Types of nanotechnology-based drug delivery systems and their delivery process

Understanding the Limitations of Nanotechnology 

Young scientists today need to focus on solving problems that truly matter. As Tom Friedman says in his book That Used to Be Us, the first step toward a better future is realizing that something isn’t right, and that it’s up to us to make the changes [7]. 

One issue that needs attention is how people view nanotechnology. Future scientists will need to help reshape that perception. A big part of this change is stopping the spread of misleading information. Sometimes, research results that only apply in very specific lab conditions are exaggerated by the media with flashy, futuristic language. While this might help grab public interest and bring in funding, it can also cause problems. 

Researchers may feel pressured to tell dramatic stories just to get support, rather than focusing on solving real-world issues [3]. Reviewers at funding agencies who may not fully understand the science—often expect something new and exciting, even if the existing technology already works well. For example, it’s hard to come up with something more impressive than nanoparticles that can “lock onto cancer cells.” But that kind of expectation can make it tough for scientists to stay grounded and practical. 

Table 2. Advantages and limitations of nanoparticles

History of Drug-Delivery Technologies 

To understand how today’s nanotech drug delivery systems came to be, it helps to look back at the history of controlled drug delivery. This field has been around for about 60 years [6]. The first wave of innovation started in the 1950s and continued through the 1970s. During that time, scientists figured out the basic ways to control how drugs are released in the body. Most of the products were designed to be taken by mouth or absorbed through the skin, and they could release medicine over 12 hours or even up to a week. 

After that, from 1980 to 2010, the second phase of development didn’t bring as many useful products. Researchers tried to create systems that released drugs at a constant rate, but it turned out that wasn’t really necessary. A few long-acting injection-based products were made, but they were small in number compared to the many oral controlled-release medicines already available. Scientists also tried to develop smart systems-like insulin delivery that responds to blood sugar levels-but those ideas didn’t work well in practice [6]. It’s hard to build a tiny device that can both sense glucose and release insulin properly inside the body. 

Then, in the early 2000s, the National Nanotechnology Initiative sparked a wave of excitement around nanotech [8]. Suddenly, anything labeled “nano” was seen as new and cutting-edge. People believed that shrinking materials down to the nanoscale would give them special properties that larger materials couldn’t offer. Because of that belief, just making something nano-sized was considered enough to call it innovative—even if it didn’t solve any real problems. 

Convenient Misconceptions 

In cancer research, a lot of excitement around nanotechnology started when scientists noticed something interesting in mice. Tiny particles, called nanoparticles, seemed to gather more easily in tumors-a behavior known as the EPR effect (enhanced permeation and retention) [9]. This led people to believe that only nanoparticles could do this. 

But when researchers looked more closely at the original data, they found that natural proteins like albumin and IgG actually collected in tumors even better. Another idea was that coating nanoparticles with PEG (a type of molecule) helped them stay in the bloodstream longer, which might boost the EPR effect.[10].

Because of these beliefs, many assumed that PEG-coated nanoparticles could kill tumors more effectively, and that the challenge of targeting cancer with drugs was partly solved. In reality, these ideas led to a flood of research papers-but not much progress in actual treatments for patients[3].

Figure 2. Mechanism of enhanced permeation and retention (EPR) effect in tumor targeting

Inconvenient Truth 

Nanoparticles can increase the amount of medicine that reaches a tumor by 100 to 400 percent, which sounds impressive. But there’s more to the story. In reality, over 95% of the nanoparticles end up in other parts of the body-not the tumor [1] [2]. This important detail is often ignored. 

When we look at real-world cancer treatments like Taxol, Taxotere, Abraxane, and Genexol, we see that the newer nanoparticle versions (Abraxane and Genexol) perform about the same as the older solution-based ones (Taxol and Taxotere) [2] [11]. All of them deliver similar amounts of medicine to the tumor. Taxol, Abraxane, and Genexol carry paclitaxel, while Taxotere carries a related drug called docetaxel. 

One useful thing about nanoparticles is that they help turn drugs that don’t dissolve well in water into injectable solutions-without needing harsh additives like polysorbate 80 or Cremophor EL [12] [13]. That’s a smart and practical use of nanotech. But it’s different from the popular belief that nanoparticles are always much better than regular drug solutions.  Sometimes, they’re just another way to get the job done. 

OUTLOOK AND FUTURE CHALLENGES 

To make nanoparticles truly useful in treating patients, scientists need to set clear and achievable goals. The difficulties in using nanoparticles to deliver drugs to specific areas- like tumors-can be solved by first understanding what nanoparticles can and can’t do, and then making the most of what they already offer. 

Exploit the 5% Reaching the Target Tumor 

Nanoparticles reach tumors mainly because they travel through the bloodstream. No matter how the drug is packaged, only a small amount-about 5%-actually ends up at the tumor [1] [2]. However, nanoparticles tend to stay near the tumor longer than regular drug molecules because they don’t easily flow back into the blood. This helps more of the drug build up around the tumor. 

Most current nanoparticles don’t carry much drug-usually only about 10% of their weight. But if we can increase that amount five times, it would be like delivering 25% of the total dose to the tumor. One way to do this is by using the drug itself in crystal form, instead of putting it inside carriers like liposomes. These drug nanocrystals can be nearly 100% active drug [12]. Their surfaces can be coated with proteins or polymers to help them stick to cells or stay stable. Even if the drug percentage drops a bit due to the coating, most of the particle is still the drug itself. 

Of course, this also means more drug might reach other parts of the body, so it’s important to design nanoparticles that release the drug only in the right environment-like near a tumor- to reduce side effects. If we can make nanoparticles that carry more drug and release it in a controlled way, drug delivery could improve quickly. 

But there’s another issue: once nanoparticles deliver their drug, they need to leave the tumor site. If they stay behind, they might block new nanoparticles from getting in. For example, some liposomes have been found still sitting near blood vessels a week after being injected [14]. Other studies show that many nanoparticles don’t fully break down even after a week [15]. That’s why it’s important to design nanoparticles that can break down or clear out at the right time. Unfortunately, this part of the design is often overlooked. 

Figure 4. Approximate biodistribution of intravenously administered nanoparticles in the body

Entering the Tumor Cells 

For a cancer drug to work well, it needs to get inside the tumor cells-not just reach the area around them. That’s why improving how nanoparticles interact with cells is so important. To help with this, a new method called the “nanocage” was developed. Professor In San Kim and his team created a special cage-like structure that sticks strongly to cell receptors [16]. They used specific peptides-tiny protein pieces-that were added to the surface of the cage. These peptides naturally group together on the cage, which boosts their ability to bind to cells. This stronger connection can make the treatment much more effective. If these nanocages are added to drug particles, they could greatly improve how well the drug works. 

Another benefit of nanoparticles that stick well to cells is that they can spread more evenly inside the tumor. How well nanoparticles move through the tumor depends on the type of molecules attached to their surface. One helpful process is called receptor-mediated transcytosis, which helps nanoparticles move from blood vessels into the tumor tissue [17] [2]. This makes it easier for the drug to reach more cancer cells. When the drug spreads well inside the tumor, it can hit the cancer cells with stronger doses and reduce the chance of the cancer becoming resistant. While certain molecules on the nanoparticle surface may not help with getting the drug from the bloodstream to the tumor, they can improve how the drug moves within the tumor once it’s there.

Figure 5. Nanocage-mediated receptor targeting and cellular uptake in tumor cells