Targeted Drug Delivery: A Simple Guide

What is Targeted Drug Delivery? 

Targeted drug delivery is a method of delivering medication to a patient in a manner that increases the concentration of the medication in a specific site of the body.  This direct method prevents the harmful effects to healthy tissue due to drug interactions.  The goal of targeted drug delivery is to have a protected drug interaction with the diseased tissue.  

How does Targeted Drug Delivery Work? 

Targeted drug delivery heavily relies on the use of nanoparticles, which are particles of matter that are usually between 1-100 nanometers (nm) in diameter. These nanoparticles are loaded with the specific drug and then targeted to specific parts of the body where there is exclusively diseased tissue, therefore, avoiding interactions with the healthy tissue.  

Different Methods of Targeted Drug Delivery 

There are two types of targeting methods: passive and active.  

Passive Targeting: In passive targeting, the drug’s success correlates to its circulation time. The nanoparticle in passive targeting is coated with a specific substance, such as polyethylene glycol (PEG). The nanoparticles accumulate preferentially in the neoplastic tissues because of the enhanced permeability and retention (EPR) phenomenon. The drug loaded nanoparticles can stay in circulation for a longer period of time and allows for efficient localization of the drug within the tumor microenvironment.  

Active Targeting: In active targeting, it is important to know the nature of the cell that the drug will be targeted to. Then, researchers can utilize cell- specific ligands that will allow the nanoparticle to bind to that specific cell directly. The nanoparticles bind directly to the receptors on the cell that they are intended to target. Therefore, the cells that are targeted actively uptake the nanoparticles themselves.  

Benefits of Drug Targeting in Healthcare  

Progress in the field of drug targeting has changed the landscape of cancer therapy. Targeted therapy is a type of cancer treatment that targets proteins that control how cancer cells grow, divide, and spread. It is the foundation of precision medicine. One reason cancer cells thrive is their ability to hide from the immune system. With the new advancements in targeted drug delivery, cancer cells can be marked as dangerous, so it is easier for the immune system to find and destroy them. In addition, different drug targeting methods forces cancer cells to go through the process of cell death, which is called apoptosis.  

Challenges Associated with Drug Targeting 

Along with its benefits, drug targeting has its drawbacks. Cancer cells can become resistant to targeted therapies, which can cause the medication to no longer be able to interact with cancerous cells as they take on different forms. Drugs for some targets are hard to develop, as the target’s structure, and function can vary greatly. Furthermore, side effects can occur such as problems with blood clotting, fatigue, and skin problems.  

Importance of Targeted Drug Delivery 

Targeted drug delivery and drug delivery systems are important because they allow for the protection of the surrounding and non-diseased tissues in the body. This helps maintain the required plasma and tissue drug levels in the body and helps prevent any damage and contamination to healthy tissue. With targeted drug delivery, lower doses of the medicine are required to be effective so there is greater control over toxicity within the body. In addition, targeted drug delivery can be used to treat many diseases, such as diabetes, cardiovascular diseases, and cancerous tumors.