Oh Great: New Syringe Makes Really Thick Fluids Injectable

Syringe disassembled with green lines showing injection length
Jose-Luis Olivares, MIT

As if regular needles weren’t bad enough, researchers at MIT have developed a syringe that can inject extra-thick medicines into our bodies. While it might sound terrifying, it could bring critical drugs to more people than ever (and it doesn’t look bad at all).

Chemistry Counts

The fluids under question are known as biopharmaceuticals, drugs that are generally produced from proteins. These drugs can be tailored based on a particular person’s chemistry, providing personalized treatment that can be much more effective than broad-spectrum drugs. They also have fewer side effects as they are “body-friendly” and can be useful in eliciting immune responses other drugs can’t.

“You can tailor very specific proteins or molecules that bind to very specific receptors in the body,” said Vishnu Jayaprakash, a graduate student in MIT’s mechanical engineering department. “They enable a degree of personalization, specificity, and immune response that just isn’t available with small-molecule drugs. That’s why, globally, people are pushing toward biologic drugs.”

Too Thick for Comfort

The problem is that such drugs tend to be quite viscous, which has meant that, for the most part, they have to be diluted and injected using IV lines. This makes it challenging to create biopharmaceuticals that could be self-injected in areas where access to medical facilities is difficult.

“Where drug delivery and biologics are going, injectability is becoming a big bottleneck, preventing formulations that could treat diseases more easily,” said Kripa Varanasi, MIT professor of mechanical engineering. “Drugmakers need to focus on what they do best, and formulate drugs, not be stuck by this problem of injectability.”

Bill Gates to the Rescue!

Varanasi has previously worked with the issue of dispensing fluids, so when the Bill and Melinda Gates Foundation decided they wanted to tackle the problem of injectability, he was a natural contact. Not only did Varanasi see the benefits of pursuing a new type of syringe for biopharmaceuticals, but he says that such a device could help people stay home and self-administer other drugs such as vaccines.

“Self-administration of drugs or vaccines can help democratize access to health care,” he said.

Varanasi and his team created a syringe with two barrels, one inside the other. The outer barrel holds a bio-friendly lubricant, and the center barrel holds the drug. As the plunger is pressed, the drug is coated in the lubricant, which allows it to flow out of the needle tip easily. When trying to use a typical needle to dispense the thicker liquids, it is practically impossible to push the plunger to get the fluid to go through the needle. Using the new syringe cuts resistance by seven times, allowing the drug to flow.

As for what lubricant is used, Varanasi says it depends on the drug being dispensed.

“The syringe device is a platform technology, and so the lubricating fluid is chosen based on drug formulation,” he told MindBounce. “The lubricating fluid can be chosen from numerous biocompatible fluids that are most appropriate for the drug-lubricant combination and have the right wetting properties with the syringe and needle surfaces to promote flow.”

The new syringe will allow over 100 drugs previously considered too thick to now be dispensed with simple injections.

The work has been published in the peer-reviewed journal Advanced Healthcare Materials and is detailed in the MIT video below.