What Is Nanomedicine? Examples in Vaccines & Cancer Care

Nanomedicine applies nanotechnology to healthcare, using engineered particles to interact with biological systems at the molecular level. A nanometer is one-millionth of a millimeter; for scale, a human hair is about 80,000 nanometers wide. The goal of nanomedicine is to use these tiny tools to monitor, repair, and improve biological systems.

Targeted Drug Delivery in Cancer Treatment

A developed application of nanomedicine is targeted drug delivery for cancer. Nanoparticles act as vehicles to transport chemotherapy drugs directly to tumor cells, reducing harm to healthy tissues. This approach addresses a limitation of conventional chemotherapy, where side effects result from the drug affecting the entire body. By encapsulating drugs in nanoparticles, their activity is concentrated at the tumor site.

An example is Doxil, a liposome—a tiny, spherical fat bubble—that contains the chemotherapy drug doxorubicin. The nanoparticle’s design takes advantage of the “enhanced permeability and retention” (EPR) effect. Tumor blood vessels are leaky, with gaps larger than those in healthy tissue, allowing Doxil particles to pass through and accumulate in the tumor.

Abraxane uses a different strategy to deliver the chemotherapy agent paclitaxel, binding the drug to nanoparticles made of albumin, a protein found in blood. This design avoids the harsh chemical solvents used in older formulations, which were responsible for many side effects. The albumin-bound nanoparticles are transported through the bloodstream and are preferentially taken up by tumors, leading to a higher drug concentration at the cancer site.

Advanced Diagnostics and Medical Imaging

Nanotechnology is refining the tools doctors use to find and visualize diseases. In this context, nanoparticles are used for detection rather than treatment, enhancing imaging methods and forming the basis of new diagnostic tests for earlier, more accurate diagnoses.

For instance, superparamagnetic iron oxide nanoparticles (SPIONs) serve as contrast agents for magnetic resonance imaging (MRI). When injected, these iron particles improve the clarity of MRI scans by altering the magnetic properties of nearby water molecules. This makes diseased tissues stand out more distinctly, helping radiologists spot abnormalities.

Nanotechnology is also used to develop highly sensitive biosensors. Gold nanoparticles can be engineered to change color when they contact specific disease biomarkers in a fluid sample like blood or urine. This property is the basis for rapid, point-of-care diagnostic tests that can provide results in minutes rather than days.

Nanoparticles in Modern Vaccines

Nanotechnology has advanced modern vaccine development, particularly through the use of lipid nanoparticles (LNPs). These particles were important for the success of the mRNA vaccines for COVID-19. The primary obstacle for an mRNA vaccine was the fragility of the mRNA molecule, which is easily destroyed in the body and struggles to enter human cells.

LNPs solve this problem by acting as a protective delivery vehicle. The nanoparticle is a fatty shell that encases the delicate mRNA, shielding it from degradation after injection. This protective bubble is engineered to fuse with human cells, releasing its mRNA payload directly into the cell’s interior.

Once inside, the cell’s machinery reads the mRNA instructions and produces a specific viral protein. This process triggers the immune system to recognize the viral protein as foreign and build a defensive response, leading to immunity. This delivery system for genetic material is a significant advance, distinct from how nanoparticles deliver pre-made chemotherapy drugs.

Therapeutic Nanoparticles

Nanoparticles can also be therapeutic agents themselves, not just delivery vehicles. In this approach, the nanoparticle’s physical properties are harnessed to cause a therapeutic effect. These nanoparticles are designed to be harmless on their own but become active when stimulated by an external source, such as light.

An example is photothermal therapy, a technique that uses heat to destroy cancer cells. Inert nanoparticles, such as gold nanoshells, are administered and accumulate in a tumor. When a laser is shone on the area, the nanoshells absorb the light energy and convert it into intense heat. This localized heating, known as thermal ablation, destroys the cancer cells while leaving adjacent healthy tissue unharmed.

Nanotechnology in Regenerative Medicine

Nanotechnology offers tools for regenerative medicine, which focuses on repairing or rebuilding damaged tissues and organs. Nanomaterials are used to build scaffolds that mimic the natural environment of cells, encouraging them to grow and form new, functional tissue.

Scientists can create three-dimensional scaffolds from nanofibers that replicate the body’s extracellular matrix—the natural support structure that surrounds cells. These nanofiber scaffolds can be produced using techniques like electrospinning. A patient’s own cells can be seeded onto these scaffolds to grow new tissue, such as skin for burn victims or cartilage to repair joints.

In bone regeneration, nanoparticles are incorporated into materials to foster the growth of new bone. For instance, nanohydroxyapatite, a nano-sized version of the natural mineral component of bone, can be added to implant materials. Its presence promotes the adhesion and growth of bone-forming cells, accelerating healing in fractures and improving the integration of dental implants.