Tag Archives: red blood cells

Red-Blood-Cell “Hitchhikers” Transport Drugs to Specific Targets

A new drug-delivery technology which uses red blood cells (RBCs) to shuttle nano-scale drug carriers, called RBC-hitchhiking (RH), has been found in animal models to dramatically increase the concentration of drugs ferried precisely to selected organs, according to a study published in Nature Communications this month by researchers from the Perelman School of Medicine at the University of Pennsylvania. This proof-of-principle study points to ways to improve drug delivery for some of the nation’s biggest killers, such as acute lung disease, stroke, and heart attack.

The vast majority of drugs fail because they spread throughout the body, landing in nearby organs where they can cause intolerable side effects, as opposed to directly targeting the areas that are really in need,” said first author Jake Brenner, MD, PhD, an assistant professor of Pulmonary Medicine and Critical Care and of Pharmacology. “By massively increasing the drug concentrations that are hitting specific tissues, the RBC hitchhikers should decrease potential side effects and improve the efficacy of drugs delivered to target organs.”

The team showed that RH can safely transport nano-scale carriers of drugs to chosen organs by targeted placement of intravascular catheters, in mice, pigs, and in ex vivo human lungs, without causing RBC or organ toxicities.

Red blood cells are a particularly attractive carrier due to their biocompatibility and known safety in transfusions,” said senior author Vladimir Muzykantov, MD, PhD, a professor of Systems Pharmacology and Translational Therapeutics. “In just a few short years since we began this work, we are now on the brink of mapping out ways to test it in clinical trials.”

The researchers found that RH drug carriers injected intravenously increased drug uptake by about 40-fold in the lungs compared to absorption of freely circulating drug carriers in blood. In addition, injecting the RH drug carriers into the carotid artery (a major blood vessel in the neck that delivers blood to the brain, neck, and face) delivers 10 percent of the injected dose to the brain, which is about 10 times higher than what is achieved through older methods such using antibodies to guide drugs to their intended targets. Such impressive drug delivery to the brain could be used to treat acute strokes, the fourth leading cause of death in the U.S.

Development of RH technology has also revealed a potentially fundamental process that hold enormous clinical promise. “The body’s largest surface area of cell-to-cell interaction is observed between red blood cells and blood vessel linings, so it is intriguing to think that our RH technology has uncovered a phenomenon in which RBCs naturally transport cargo on their surfaces,” said Muzykantov.

Source: https://www.pennmedicine.org/

Nanorobots Clear Bacteria From Blood

Engineers at the University of California San Diego have developed tiny ultrasound-powered robots that can swim through blood, removing harmful bacteria along with the toxins they produce. These proof-of-concept nanorobots could one day offer a safe and efficient way to detoxify and decontaminate biological fluids.

Researchers built the nanorobots by coating gold nanowires with a hybrid of platelet and red blood cell membranes. This hybrid cell membrane coating allows the nanorobots to perform the tasks of two different cells at once—platelets, which bind pathogens like MRSA bacteria (an antibiotic-resistant strain of Staphylococcus aureus), and red blood cells, which absorb and neutralize the toxins produced by these bacteria. The gold body of the nanorobots responds to ultrasound, which gives them the ability to swim around rapidly without chemical fuel. This mobility helps the nanorobots efficiently mix with their targets (bacteria and toxins) in blood and speed up detoxification.

The work, published May 30 in Science Robotics, combines technologies pioneered by Joseph Wang and Liangfang Zhang, professors in the Department of NanoEngineering at the UC San Diego Jacobs School of Engineering. Wang’s team developed the ultrasound-powered nanorobots, and Zhang’s team invented the technology to coat nanoparticles in natural cell membranes.

SEM image of a MRSA bacterium attached to a hybrid cell membrane coated nanorobot

By integrating natural cell coatings onto synthetic nanomachines, we can impart new capabilities on tiny robots such as removal of pathogens and toxins from the body and from other matrices,” said Wang. “This is a proof-of-concept platform for diverse therapeutic and biodetoxification applications.”

The idea is to create multifunctional nanorobots that can perform as many different tasks at once,” adds co-first author Berta Esteban-Fernández de Ávila, a postdoctoral scholar in Wang’s research group at UC San Diego. “Combining platelet and red blood cell membranes into each nanorobot coating is synergistic—platelets target bacteria, while red blood cells target and neutralize the toxins those bacteria produce.

Source: http://jacobsschool.ucsd.edu/