The Future of Medicine: Elastic Superglue and DNA Clamps

nanomachineryIf there’s one thing medical science is looking to achieve, it’s ways of dealing with sickness and injuries that are less invasive. And now more than ever, researchers are looking to the natural world for solutions. Whether it is working with the bodies own components to promote healing, or using technologies that imitate living organism, the future of medicine is all about engineered-natural solutions.

Consider the elastic glue developed by associate professor Jeffrey Karp, a Canadian-born medical researcher working at Harvard University. Created for heart surgery, this medical adhesive is designed to replace sutures and staples as the principle means of sealing incisions and defects in heart tissue. But the real kicker? The glue was inspired by sticky natural secretions of slugs.

hlaa-4Officially known as hydrophobic light-activated adhesive (HLAA), the glue was developed in a collaboration between Boston Children’s Hospital, MIT, and Harvard-affiliated Brigham and Women’s Hospital. And in addition to being biocompatible and biodegradable (a major plus in surgery), it’s both water-resistant and elastic, allowing it to stretch as a beating heart expands and contracts.

All of this adds up to a medical invention that is far more user-friendly than stitches and staples, does not have to be removed, and will not cause complications. On top of all that, it won’t complicate healing by restricting the heart’s movements, and only becomes active when an ultraviolet light shines on it, so surgeons can more accurately bind the adhesive exactly where needed.

hlaa-3The technology could potentially be applied not just to congenital heart defects, but to a wide variety of organs and other body parts. In an recent interview with CBC Radio’s Quirks & Quarks, Karp explained the advantages of the glue:

Sutures and staples really are not mechanically similar to the tissues in the body, so they can induce stress on the tissue over time. This is a material that’s made from glycerol and sebacic acid, both of which exist in the body and can be readily metabolized. What happens over time is that this material will degrade. Cells will invade into it and on top of it, and ideally the hole will remain closed and the patient won’t require further operations.

In lab tests, biodegradable patches coated with HLAA were applied to holes in the hearts of live pigs. Despite the high pressure of the blood flowing through the organs, the patches maintained a leakproof seal for the 24-hour test period. HLAA is now being commercially developed by Paris-based start-up Gecko Biomedical, which hopes to have it on the market within two to three years.

dnaclampIn another recent development, scientists at the Université de Montréal have created a new DNA clamp capable of detecting the genetic mutations responsible for causing cancers, hemophilia, sickle cell anemia and other diseases. This clamp is not only able to detect mutations more efficiently than existing techniques, it could lead to more advanced screening tests and more efficient DNA-based nanomachines for targeted drug delivery.

To catch diseases at their earliest stages, researchers have begun looking into creating quick screening tests for specific genetic mutations that pose the greatest risk of developing into life-threatening illnesses. When the nucleotide sequence that makes up a DNA strand is altered, it is understood to be a mutation, which specific types of cancers can be caused by.

DNA-MicroarrayTo detect this type of mutation and others, researchers typically use molecular beacons or probes, which are DNA sequences that become fluorescent on detecting mutations in DNA strands. The team of international researchers that developed the DNA clamp state that their diagnostic nano machine allows them to more accurately differentiate between mutant and non-mutant DNA.

According to the research team, the DNA clamp is designed to recognize complementary DNA target sequences, binds with them, and form a stable triple helix structure, while fluorescing at the same time. Being able to identify single point mutations more easily this way is expected to help doctors identify different types of cancer risks and inform patients about the specific cancers they are likely to develop.

dna_cancerDiagnosing cancer at a genetic level could potentially help arrest the disease, before it even develops properly. Alexis Vallée-Bélisle, a Chemistry Professor at the Université de Montréal, explained the long-term benefits of this breakthrough in a recent interview:

Cancer is a very complex disease that is caused by many factors. However, most of these factors are written in DNA. We only envisage identifying the cancers or potential of cancer. As our understanding of the effect of mutations in various cancer will progress, early diagnosis of many forms of cancer will become more and more possible.

Currently the team has only tested the probe on artificial DNA, and plans are in the works to undertake testing on human samples. But the team also believes that the DNA clamp will have nanotechnological applications, specifically in the development of machines that can do targeted drug-delivery.

dna_nanomachineFor instance, in the future, DNA-based nanomachines could be assembled using many different small DNA sequences to create a 3D structure (like a box). When it encounters a disease marker, the box could then open up and deliver the anti-cancer drug, enabling smart drug delivery. What’s more, this new DNA clamp could prove intrinsic in that assembly process.

Professor Francesco Ricci of the University of Rome, who collaborated on the project, explained the potential in a recent interview:

The clamp switches that we have designed and optimized can recognize a DNA sequence with high precision and high affinity. This means that our clamp switches can be used, for example, as super-glue to assemble these nano machines and create a better and more precise 3D structure that can, for example, open in the presence of a disease marker and release a drug.

Hmm, glues inspired by mollusc secretions, machines made from DNA. Medical technology is looking less like technology and more like biology every day now!

Sources: cbc.ca, gizmag.com, (2)

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