Nanomedicine

As the landscape of the healthcare field expands, new advances are coming forth, and one such area of interest is nanomedicine. Existing on a miniature scale called nanometres, nanomedicine and technology provide a revolutionary solution to many modern-day problems faced by the scientific community. Through this article, we’ll aim to explore what exactly nanomedicine is, its importance, its use in medicine, as well as its limitations and future prospects.

The nanoscale

When mentioning nanomedicine or nanotechnology, we refer to materials and particles existing on the nanoscale. This lies between 1-100 nanometres. For reference, human hair is 80,000-100,000 nanometres wide, so comparatively, the technology is much smaller. Although the technology may seem small, its impact is far too significant to be discredited. Due to their smaller size, the nanoparticles hold several advantages, making them useful in biomedicine, these include providing greater surface area for molecular interactions in the body, and they are much easier to manipulate, allowing for greater control and precision in terms of diagnostics and medicine delivery (Figure 1).

Cancer drug delivery systems

Nanotechnology in the field of medicine is being widely used and tested with regards to its application as a drug delivery system. More recently, it’s being investigated for its increased precision in delivering anti-cancer drugs to patients. Nanotechnology enables precise drug delivery through the construction of nanoscale infrastructures called nanoparticles. These can be filled with anti-cancer drug treatments, and their outer structure can be further designed to include elements which target folate receptors, such as folic acid (B9 vitamin), thus increasing their affinity for specific receptors in the body. Folate receptors tend to be overexpressed on the surface of many cancers, including pancreas, breast, and lung. So, by increasing selectivity and targeting only the cells which overexpress these receptors, the nanoparticles can deliver chemotherapy drugs with increased precision. This increased accuracy results in decreased cellular toxicity to surrounding non-cancerous tissues whilst also reducing side effects.

In current experiments, lipid nanoparticles loaded with the anti-cancer drug edelfosine were tested on mice with mantle cell cancer. Lipid nanoparticles offer several advantages as a drug delivery system, including biocompatibility, greater physical stability, increased tolerability, and controlled release of the encapsulated drug. Lipid nanoparticles are also advantageous for their ability to be size specific to a tumour. In the study, in vivo experimentation using mice that contained mantle cell lymphoma was used, and they were administered 30mg/kg of the encapsulated drug. After administering the edelfosine loaded nanoparticles every 4 days, it was found that the process of metastasis had been removed; this means that cancer cells could not spread to other parts of the body. Additionally, it was also found that because of the way the nanoparticles were absorbed into the lymphatic system, they could accumulate in the thoracic duct providing precise and slow release of the drug over time, thus preventing metastasis (Figure 2).

Imaging and diagnostics

Another area of use for nanotechnology includes imaging and diagnostics. This area of expertise is regarded as theranostics, which involves using nanoparticles as detectors to help locate the area of the body affected by a disease, such as the location of a tumour, and aid in diagnosing illnesses. With regards to diagnostics, nanoparticles can also help identify what stage of the disease is being observed as well as enable us to garner more information to form a concrete treatment programme for the patient, thus providing a personalised touch to their care. Nanomaterials can be used to engineer different types of nanoparticles, which can enhance contrast on CT and MRI scans so that diseases can be detected more easily by being more visible when compared to traditional scans. 

In collaboration with Belcher et al., Bardhan worked to collectively develop different formulations of polymers that would be most effective in imagining and detecting cancers earlier. In the figure below, a nanoparticle made of a core shell was used for imaging. It comprises a yellow polymer with a red fluorescent dye to increase imagining contrast of the area and a blue lanthanide nanoparticle. When the lanthanide particles are excited by a light source, fluorescence in the near infrared range (NIR-II) is emitted, allowing for clear contrast and imaging. This can be seen in the figure below. From the colours involved, the tumour being imaged could be investigated more thoroughly in how it was distributed and learn more about its microenvironment in a mouse affected by ovarian cancer (Figure 3).

Nanobots

In recent times, new investment in the form of nanorobots has been made apparent. Nanorobots are nanoelectromechanical systems whose size is very similar to human organelles and cells, so there are a variety of ways they could be helpful in healthcare, such as in the field of surgery. Traditionally, surgical tools can be limited to work on a small scale. However, with nanorobots, it can be possible to access areas unreachable to surgical tools and catheters whilst also reducing recovery time and infection risk, as well as granting greater control and accuracy over the surgery.

In a study conducted by Chen et al. (2020), the researchers manipulated magnetotactic bacterial microrobots to kill a bacteria known as Staphylococcus aureus enabled by magnetic fields to target them. Using a microfluidic chip, the microrobots were guided to the target site and then were programmed to attach themselves to the bacteria. Once connected, the viability of the bacteria was reduced due to the swinging magnetic fields generated by the device. Although this research is promising, further research must be conducted to understand the compatibility of these nanotechnologies with the human body and any implications they may have in side effects (Figure 4).

Challenges and safety concerns

From the evidence explored above, it is evident that nanotechnology holds much promise in the field of healthcare. However, they are not without their challenges and resignations when introducing their use to human bodies. The human body is incredibly complex, and therefore the complete biocompatibility of nanoparticles, particularly nanobots, is currently under-researched and under reviewed. To extensively use them, it is vital first to understand how safe they are and their efficacy in treatment and diagnosis. Below is a summary of some of the advantages and disadvantages of these nanotechnologies (Figure 5).

The future of nanotechnology in biomedicine

In conclusion, nanotechnology indicates an extensive and optimistic field at the forefront of changing medical care from diagnosis to treatment. It has the potential to answer many pressing questions in healthcare including decreasing cytotoxicity via a precise drug delivery system, increased accuracy in diagnosis, and possibly becoming a novel tool in surgery. Although it is imperative for there to be new and evolved techniques to increase the quality of care for patients, it is vital not to rush and to be thorough in our approach. This involves undergoing further research, including conducting clinical trials when investigating the use of nanotechnology inside the human body; this will test for tissue compatibility, side effects, efficacy, and even dosage when using nanoparticles for drug delivery. In summary, the transformative role of nanomedicine is undeniable. It offers a path to a more personalised and precise healthcare system, allowing researchers to reshape treatment, diagnosis, and patient well-being, though its limitations are yet to be overcome.

Written by Irha Khalid

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