How to Program DNA Robots

Scientists have worked out how to best get DNA to communicate with membranes in our body, paving the way for the creation of ‘mini biological computers’ in droplets that have potential uses in biosensing and mRNA vaccinesUNSW’s Dr Matthew Baker and the University of Sydney’s Dr Shelley Wickham co-led the study, published recently in Nucleic Acids Research.

It discovered the best way to design and build DNA ‘nanostructures’ to effectively manipulate synthetic liposomes tiny bubbles which have traditionally been used to deliver drugs for cancer and other diseases. By modifying the shape, porosity and reactivity of liposomes, there are far greater applications, such as building small molecular systems that sense their environment and respond to a signal to release a cargo, such as a drug molecule when it nears its target.

Lead author Dr Matt Baker from UNSW’s School of Biotechnology and Biomolecular Sciences says the study discovered how to buildlittle blocks” out of DNA and worked out how best to label these blocks with cholesterol to get them to stick to lipids, the main constituents of plant and animal cells.

The study discovered the best way to design and build DNA ‘nanostructures’ to effectively manipulate synthetic liposomes (pictured) – tiny bubbles which have traditionally been used to deliver drugs for cancer and other diseases

One major application of our study is biosensing: you could stick some droplets in a person or patient, as it moves through the body it records local environment, processes this and delivers a result so you can ‘read out’ the local environment,” Dr Baker says.

Liposome nanotechnology has shot into prominence with the use of liposomes alongside RNA vaccines such as the Pfizer and Moderna COVID-19 vaccines. “This work shows new ways to corral liposomes into place and then pop them open at just the right time,” Dr Baker says. “What is better is because they are built from the bottom-up out of individual parts we design, we can easily bolt in and out different components to change the way they work.”


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.