The future that is fast approaching us is one filled with possibilities, many of which were once thought to be the province of science fiction. Between tricorders and other new devices that can detect cancer sooner and at a fraction of the cost, HIV vaccines and cures, health monitoring tattoos and bionic limbs, we could be moving into an age where all known diseases are curable and physical handicaps will be non-existent.
And in the past few months, more stories have emerged with provide hope for millions of people living with diseases, injuries and disabilities. The first came just over three weeks ago from University of California, Berkley, where researchers have been working with an engineered virus which they claim could help cure blindness. As part of a gene therapy program, this treatment has been shown to effectively correct a rare form of inherited blindness.
For the past six years, medical science has been using adeno-associated viruses (AAV) as part of a gene therapy treatment to correct inherited retinal degenerative disease. However, the process has always been seen as invasive, since it involves injected the AAVs directly into a person’s retina with a needle. What’s more, the rpocess has shown itself to be limited, in that the injected virus does not reach all the retinal cells that need repair.
But as Professor David Schaffer, the lead researcher on the project, stated in an interview with Science Translational Medicine:
[D]octors have no choice because none of the gene delivery viruses can travel all the way through the back of the eye to reach the photoreceptors – the light sensitive cells that need the therapeutic gene.
Building on this and many more years of research, Prof David Schaffer and his colleagues developed a new process where they generated around 100 million variants of AAV and then selected five that were effective in penetrating the retina. They then used the best of these, a strain known as 7m8, to transport genes to cure two types of hereditary blindness on a group of mice.
In each case, the engineered virus delivered the corrective gene to all areas of the retina and restored retinal cells nearly to normal. But more importantly, the virus’ ability to penetrate the retina on its own makes the process far less invasive, and will likely be far more cost-effective when adapted to humans. And the process is apparently very convenient:
[W]e have now created a virus that you just inject into the liquid vitreous humor inside the eye and it delivers genes to a very difficult-to-reach population of delicate cells in a way that is surgically non-invasive and safe. It’s a 15-minute procedure, and you can likely go home that day.
Naturally, clinical trials are still needed, but the results are encouraging and Professor Schaffer indicated that his team are busy at work, now collaborating with physicians to identify the patients most likely to benefit from this gene-delivery technique.
Next up, there was the announcement back at the end of May that researchers from North Carolina State and University of North Carolina Chapel Hill had found yet another medical use for nanoparticles. In there case, this consisted of combating a major health concern, especially amongst young people today: diabetes.
In a study that was published in the Journal of Agricultural and Food Chemistry, the collaborating teams indicated that their solution of nanoparticles was able to monitor blood sugar levels in a group of mice and released insulin when their sugar levels got too high. Based on the results, the researchers claim that their method will also work for human beings with type 1 diabetes.
Each of the nanoparticles have a core of insulin that is contained with a degradable shell. When glucose levels in the blood reach high concentrations spike, the shell dissolves, releasing insulin and lowering the subject’s blood sugar. The degradable nano-network was shown to work in mice where a single injection kept blood glucose levels normal for a minimum of 10 days.
While the exact cause of this kind of diabetes is unknown, the effects certainly are. Patients living with this genetically-acquired form of the disease require several shots of insulin a day to keep their blood sugar levels under control. And even then, blindness, depression and even death can still result. What’s more, if the insulin shots are specifically calculated for the individual in question, side-effects can occur.
Hence the genius behind this new method. Not only would it relieve people who have type 1 diabetes from constantly injecting themselves, it would also remove the need to monitor their own blood sugar levels since the nanoparticles would be controlling them automatically.
In a study published recently in the Journal of Agricultural and Food Chemistry, Zhen Gu, lead author of the study claimed that the technology functions essentially the same as a pancreas. Hence another benefit of the new method, in that it could make pancreatic transplants – which are often necessary for patients with diabetes – unnecessary.
And last, but certainly not least, comes from the University of Illinois where John Rogers are developing a series of bio-absorbable electronic circuits that could help us win the war on drug-resistant bacteria. As part of a growing trend of biodegradable, flexible electronic circuits that operate wirelessly, fighting “superbugs” is just one application for this technology, but a very valuable one.
For some time now, bacteria that is resistant to antibiotics has been spreading, threatening to put the clock back 100 years to the time when routine, minor surgery was life-threatening. Some medical experts are warning that otherwise straightforward operations could soon become deadly unless new ways to fend off these infections are found. And though bacteria can evolve ways of evading chemical assaults, they are still vulnerable to direct assault.
This is how the new bio-absorbable circuits work: by heating up the virus. Each circuit is essentially a miniature electric heater that can be implanted into wounds and powered wirelessly to fry bacteria during healing before dissolving harmlessly into body fluids once their job is done. While this might sound dangerous, keep in mind that it takes only a relatively mild warming to kill bugs without causing discomfort or harm to surrounding tissues.
To fashion the circuits, Rogers and his colleagues used layers of utra-thin wafers and silk, material so thin that they disintegrate in water or body fluids or (in the case of silk) are known to dissolve anyway. For the metal parts, they used extra-thin films of magnesium, which is not only harmless but in fact an essential nutrient. For semiconductors, they used silicon membranes 300 nanometres thick, which also dissolve in water.
In addition to deterring bacteria, Rogers says that implantable, bio-absorbable RF electronics could be used to stimulate nerves for pain relief, and to stimulate bone re-growth, a process long proven to work when electrodes are placed on the skin or directly on the bone. Conceivably they could also be used to precisely control drug release from implanted reservoirs.
In other words, this is just the beginning. When it comes to the future of medicine, just about any barrier that was once considered impassable are suddenly looking quite porous…