How can nanoparticles be engineered to target specific cells or tissues?

Nanoparticles are tiny particles that can have unique properties and functions at the nanoscale, which is about 1 to 100 nanometers (a billionth of a meter). They have potential applications in many fields, including medicine, where they can be used to deliver drugs, genes, or imaging agents to specific cells or tissues in the body. However, designing nanoparticles that can target the desired sites and avoid unwanted interactions with the immune system, blood, and other organs is a challenging task that requires a combination of chemical engineering, biology, and physics. In this article, you will learn about some of the strategies and techniques that can help you engineer nanoparticles for targeted delivery.

1 Surface modification

One of the key factors that determines the fate of nanoparticles in the body is their surface properties, such as charge, hydrophobicity, shape, and size. These properties affect how nanoparticles interact with biological molecules, such as proteins, lipids, and sugars, that form a layer around them called the protein corona. The protein corona can influence the stability, circulation, and recognition of nanoparticles by cells and tissues. To control the protein corona and enhance the targeting ability of nanoparticles, you can modify their surface with different molecules, such as polymers, peptides, antibodies, or ligands, that can shield them from unwanted interactions or bind to specific receptors on the target cells or tissues.

Add your perspective

Azarmidokht G. Shirazi

Research Fellow, Future Biomanufacturing Research Hub, Manchester Institute of Biotechnology, University of Manchester
Report contribution
Surface Functionalization: Attach ligands (antibodies, peptides) to nanoparticle surfaces Size and Shape:Tailor nanoparticle size and shape Charge: Control nanoparticle charge Responsive Materials: Use materials responsive to physiological conditions (pH, enzymes) for triggered release at specific locations Encapsulation: Encapsulate therapeutic agents within nanoparticles Magnetic Targeting: Apply external magnetic fields for site-specific accumulation Active and Passive Targeting: Passive targeting through enhanced permeability in certain tissues, Active targeting via ligands for specific cell recognition. Biochemical Affinity: Leverage biochemical interactions Stealth Coating: Biocompatible coatings (PEGylation) to evade immune response

Like

2 Stimuli-responsive nanoparticles

Another way to improve the targeting of nanoparticles is to make them responsive to external or internal stimuli, such as light, heat, magnetic fields, pH, or enzymes. These stimuli can trigger changes in the structure, size, shape, or surface of nanoparticles, allowing them to release their cargo, change their biodistribution, or enhance their penetration into the target sites. For example, you can design nanoparticles that can release drugs when exposed to a laser beam or an ultrasound wave, or nanoparticles that can change their charge or hydrophobicity when they encounter acidic or enzymatic environments in tumors or inflammation sites.

Add your perspective

3 Self-assembling nanoparticles

A third approach to engineer nanoparticles for targeted delivery is to use self-assembly, which is the process of spontaneous formation of ordered structures from smaller components. Self-assembly can create nanoparticles with complex shapes, structures, and functions that can mimic natural systems, such as viruses, cells, or tissues. You can use different types of molecules, such as DNA, proteins, lipids, or polymers, to create self-assembling nanoparticles that can encapsulate drugs, genes, or imaging agents, and that can recognize and interact with specific cells or tissues. For example, you can use DNA to create nanoparticles that can form different shapes, such as spheres, rods, or cages, and that can bind to complementary DNA sequences on the target sites.

Add your perspective

4 Multifunctional nanoparticles

A fourth strategy to engineer nanoparticles for targeted delivery is to combine different functionalities and properties in one nanoparticle. This can enhance the performance, efficiency, and safety of nanoparticles, as well as enable multiple applications, such as diagnosis, therapy, and monitoring. You can create multifunctional nanoparticles by incorporating different components, such as metals, semiconductors, polymers, or biomolecules, that can provide different functions, such as imaging, drug delivery, gene delivery, or magnetic manipulation. For example, you can create nanoparticles that can simultaneously deliver drugs and genes to tumors, and that can also produce fluorescence or magnetic signals for imaging and tracking.

Add your perspective

5 Nanoparticle synthesis and characterization

The final step in engineering nanoparticles for targeted delivery is to synthesize and characterize them. This involves using different methods and techniques to create, modify, and analyze nanoparticles, such as chemical reactions, physical processes, or biological methods. You also need to measure and evaluate the properties and functions of nanoparticles, such as size, shape, surface, composition, stability, toxicity, biocompatibility, biodistribution, targeting, and efficacy. You can use different instruments and assays to perform these measurements and evaluations, such as microscopy, spectroscopy, chromatography, electrophoresis, or cell culture.

Add your perspective

Arnob Das

Staff Scientist - Applied and Emerging Materials Group @ LLNL
Report contribution
Lipid nanoparticles are a salient model system for targeted delivery as carriers for sustained mRNA delivery, with recent applications in COVID-19 vaccines and CAR-T cancer therapy. Despite iterating chemical combinatorial libraries for optimizing cellular uptake, a missing feature in nanoparticle synthesis is the lack of dynamical adjustment to pH changes. For example, nucleic acids like mRNA buffer for large pH changes and prior to uptake, intermediary cellular structures called endosomes undergo a large pH change. If nanoparticles were designed with functional groups that could modulate nanoparticle cellular interfacing from deviations in expected acidity/basicity, it would act as an important generalizable feature for targeted delivery.

Like

6 Here’s what else to consider

This is a space to share examples, stories, or insights that don’t fit into any of the previous sections. What else would you like to add?

Add your perspective

How can nanoparticles be engineered to target specific cells or tissues?

1

2

3

4

5

6

1 Surface modification

2 Stimuli-responsive nanoparticles

3 Self-assembling nanoparticles

4 Multifunctional nanoparticles

5 Nanoparticle synthesis and characterization

6 Here’s what else to consider

Chemical Engineering

Rate this article

Thanks for your feedback

More articles on Chemical Engineering

More relevant reading