Johns Hopkins Medicine researchers have developed a color-coded test that quickly signals whether newly developed nanoparticles—ultra small compartments designed to ferry medicines, vaccines and other therapies—deliver their cargo into target cells. Historically, nanoparticles have a very low delivery rate to the cytosol, the inside compartment of cells, releasing only about 1%–2% of their contents. The new testing tool, engineered specifically to test nanoparticles, could advance the search for next-generation biological medicines. The technology builds upon nanoparticles currently used against cancer and eye disease, and in vaccines for viruses including SARS-CoV-2, the virus that causes COVID-19.
“Many of the current assessment tools for nanoparticles only test whether a nanoparticle reaches a cell, not if the therapy can successfully escape the degradative environment of the endosome to reach inside the cytosol of the cell, which is where the medicine needs to be located for performance,” says Jordan Green, Ph.D., professor of biomedical engineering at the Johns Hopkins University School of Medicine. The new tool was created to track location and nanoparticle release, he said.
Previous research has estimated that only about 1%-2% of nanoparticles “eaten” by cells are able to escape the cellular compartments that trap them to avoid being digested or “spit back out.” In addition to the properties of its cargo, a nanoparticle’s chemical properties determine whether it is accepted by a cell and able to evade its cellular defenses.
To surmount such obstacles to final delivery, Green and his team designed a screening tool that assesses hundreds of nanoparticle formulations on their ability to not just reach a cell, but also how efficiently the nanoparticle can escape with its cargo to reach a cell’s interior.
The test uses mouse cells grown in the laboratory that are genetically engineered to carry a florescent marker called Gal8-mRuby, which shines orange-red when a cellular envelope that engulfs a nanoparticle opens, releasing its cargo into the cell.
Images of the process are then analyzed by a computer program that quickly tracks the nanoparticle location using red fluorescent light and quantifies how effective the nanoparticles are at being released into the cell by assessing the amount of orange-red fluorescent light. Using this technique, a laboratory can screen hundreds of unique nanoparticles for delivery in a few hours, with detailed information about the uptake of the nanoparticles and the delivery of their cargo.
In experiments in mice, Green and his team administered biodegradable nanoparticles carrying mRNA that encoded a gene called luciferase, which makes cells glow. The researchers then tracked whether the mouse cells accepted the gene and began expressing it—lighting up target cells like a lightning bug.
Green’s team found that the top-performing nanoparticles in the cellular tests had a high positive correlation to nanoparticle gene delivery performance in living mice, showing the nanoparticle assay is a good predictor of successful cargo delivery.
In further mouse studies, the researchers discovered that different chemical group combinations in the polymer-based nanoparticles led the nanoparticles to target different tissue types. By analyzing how the particles behaved in the mouse’s body, the researchers found that polymer chemical properties could direct the nanoparticle gene therapy to specific target cells, such as endothelial cells in the lungs or B cells in the spleen.
“By fine-tuning small chemical changes, we can steer a nanoparticle to specific tissues and even specific cells,” said Green. “This would allow us to develop more precisely delivered therapies, which could improve both efficacy and safety.”
Nanoparticle delivery of biological drugs is a growing field, particularly for gene therapies and vaccines.
Other researchers involved in the study include Yuan Rui, David R. Wilson, Stephany Y. Tzeng, Hannah M. Yamagata, Deepti Sudhakar, Cynthia A. Berlinicke and Donald J. Zack of the Johns Hopkins University School of Medicine; Marranne Conge of the Johns Hopkins University School of Medicine and Berea College; and Anthony Tuesca of AstraZeneca.

News
Study Shows Brain Signals Only Matter if They Arrive on Time
Signals are processed only if they reach the brain during brief receptive cycles. This timing mechanism explains how attention filters information and may inform therapies and brain-inspired technologies. It has long been recognized that [...]
Does Space-Time Really Exist?
Is time something that flows — or just an illusion? Exploring space-time as either a fixed “block universe” or a dynamic fabric reveals deeper mysteries about existence, change, and the very nature of reality. [...]
Unlocking hidden soil microbes for new antibiotics
Most bacteria cannot be cultured in the lab-and that's been bad news for medicine. Many of our frontline antibiotics originated from microbes, yet as antibiotic resistance spreads and drug pipelines run dry, the soil [...]
By working together, cells can extend their senses beyond their direct environment
The story of the princess and the pea evokes an image of a highly sensitive young royal woman so refined, she can sense a pea under a stack of mattresses. When it comes to [...]
Overworked Brain Cells May Hold the Key to Parkinson’s
Scientists at Gladstone Institutes uncovered a surprising reason why dopamine-producing neurons, crucial for smooth body movements, die in Parkinson’s disease. In mice, when these neurons were kept overactive for weeks, they began to falter, [...]
Old tires find new life: Rubber particles strengthen superhydrophobic coatings against corrosion
Development of highly robust superhydrophobic anti-corrosion coating using recycled tire rubber particles. Superhydrophobic materials offer a strategy for developing marine anti-corrosion materials due to their low solid-liquid contact area and low surface energy. However, [...]
This implant could soon allow you to read minds
Mind reading: Long a science fiction fantasy, today an increasingly concrete scientific goal. Researchers at Stanford University have succeeded in decoding internal language in real time thanks to a brain implant and artificial intelligence. [...]
A New Weapon Against Cancer: Cold Plasma Destroys Hidden Tumor Cells
Cold plasma penetrates deep into tumors and attacks cancer cells. Short-lived molecules were identified as key drivers. Scientists at the Leibniz Institute for Plasma Science and Technology (INP), working with colleagues from Greifswald University Hospital and [...]
This Common Sleep Aid May Also Protect Your Brain From Alzheimer’s
Lemborexant and similar sleep medications show potential for treating tau-related disorders, including Alzheimer’s disease. New research from Washington University School of Medicine in St. Louis shows that a commonly used sleep medication can restore normal sleep patterns and [...]
Sugar-Coated Nanoparticles Boost Cancer Drug Efficacy
A team of researchers at the University of Mississippi has discovered that coating cancer treatment carrying nanoparticles in a sugar-like material increases their treatment efficacy. They reported their findings in Advanced Healthcare Materials. Over a tenth of breast [...]
Nanoparticle-Based Vaccine Shows Promise in Fighting Cancer
In a study published in OncoImmunology, researchers from the German Cancer Research Center and Heidelberg University have created a therapeutic vaccine that mobilizes the immune system to target cancer cells. The researchers demonstrated that virus peptides combined [...]
Quantitative imaging method reveals how cells rapidly sort and transport lipids
Lipids are difficult to detect with light microscopy. Using a new chemical labeling strategy, a Dresden-based team led by André Nadler at the Max Planck Institute of Molecular Cell Biology and Genetics (MPI-CBG) and [...]
Ancient DNA reveals cause of world’s first recorded pandemic
Scientists have confirmed that the Justinian Plague, the world’s first recorded pandemic, was caused by Yersinia pestis, the same bacterium behind the Black Death. Dating back some 1,500 years and long described in historical texts but [...]
“AI Is Not Intelligent at All” – Expert Warns of Worldwide Threat to Human Dignity
Opaque AI systems risk undermining human rights and dignity. Global cooperation is needed to ensure protection. The rise of artificial intelligence (AI) has changed how people interact, but it also poses a global risk to human [...]
Nanomotors: Where Are They Now?
First introduced in 2004, nanomotors have steadily advanced from a scientific curiosity to a practical technology with wide-ranging applications. This article explores the key developments, recent innovations, and major uses of nanomotors today. A [...]
Study Finds 95% of Tested Beers Contain Toxic “Forever Chemicals”
Researchers found PFAS in 95% of tested beers, with the highest levels linked to contaminated local water sources. Per- and polyfluoroalkyl substances (PFAS), better known as forever chemicals, are gaining notoriety for their ability [...]