2. Execute
Nanoparticle Drug Delivery Systems
In the Execute phase, students move from exploration to a deeper analysis of the scientific mechanisms underlying nanomedicine. The focus is on understanding how nanoparticles can function as drug delivery systems capable of transporting therapeutic molecules to specific locations in the body.
Traditional medical treatments often rely on drugs that circulate throughout the entire bloodstream. While effective in treating disease, this approach frequently produces severe side effects because healthy tissues are also exposed to the drug.
Nanotechnology offers a solution to this problem through targeted drug delivery. Nanoparticles can be engineered to transport drugs selectively to diseased tissues, increasing treatment efficiency while reducing toxicity.
Students examine the three main stages involved in nanoparticle drug delivery.
Stage 1 – Nanoparticle Design
Scientists design nanoparticles with specific properties that determine their behavior inside the body. Important parameters include:
• particle size
• shape
• surface chemistry
• electrical charge
These characteristics influence how nanoparticles circulate in blood, interact with cells, and reach target tissues.
Stage 2 – Drug Loading
Once the nanoparticle structure is created, it is loaded with therapeutic molecules.
For example:
• Liposomes encapsulate drugs inside a lipid bilayer similar to biological membranes.
• Polymeric nanoparticles bind drug molecules to their surface.
• Carbon nanotubes can carry molecules through their hollow cylindrical structure.
This stage ensures that the drug remains stable while traveling through the body.
Stage 3 – Controlled Drug Release
After reaching the target tissue, the nanoparticle releases the drug.
Drug release can be triggered by environmental factors such as:
• pH changes in tumor environments
• specific enzymes
• temperature differences
• external stimuli such as light or magnetic fields
Controlled release allows the drug to act exactly where it is needed.
Cancer cells often present specific proteins on their surface called receptors. Scientists design nanoparticles with molecules known as ligands that bind selectively to these receptors.
This interaction follows the lock-and-key model, a concept commonly used in molecular biology.
When the nanoparticle encounters a cancer cell:
1. The ligand binds to the receptor.
2. The nanoparticle attaches to the cell membrane.
3. The cell internalizes the nanoparticle.
4. The drug is released inside the tumor cell.
Because healthy cells lack these receptors, they interact much less with the nanoparticles. As a result, targeted nanotherapy can significantly reduce damage to healthy tissues.