This past year saw a tremendous number of major medical and health science stories. It was no easy feat putting together a list of the year’s biggest breakthroughs. Ultimately, we decided on 13 — for the year, 2013, but also to represent the 13-person Medical Daily editorial team. In no particular order:

Nanoparticle Pills Could Mean No More Needles

The underlying nano-scale physics gives nanoparticles different properties than larger molecules — they not only behave differently but also can be manipulated in new ways. For years, scientists were able to deliver nano-drugs to patients via injections — but repeatedly failed when it came time to turn nanoparticles into pills. Despite their miniature size, nanoparticles were incapable of penetrating the intestinal lining, which is made of epithelial cells woven together to form an impassable barrier.

However, in the past year, a team of researchers finally cleared this difficult hurdle when they developed a new nanoparticle that can be absorbed through the digestive tract. The research team is now looking to design nanomedicines that can cross other impenetrable obstructions, including the blood-brain barrier and the placental barrier, with hopes of treating difficult-to-reach illnesses. And possibly making life easier for the millions of people worldwide who fear needles.

- Susan Scutti

3D Tech-Based 'Smart Glasses' Let Doctors See Through Patient's Skin

The technology used by the Eyes-On “smart glasses” earned its spot on this year’s list of medical breakthroughs with the promise of preserving a universal and invaluable asset: time. According to its developers, the innovation stands to transform bedside care and IV starts by allowing nurses to peer through their patient’s skin to the vasculature beneath. Just like the recently announced NanoKnife, the glasses’ “look-through” technology exemplifies the exciting emergence of interactive medical technologies.

On launch, the developers of the Eyes-On Glasses, Evena Medical, spoke about the device’s underlying technology as well as its future within clinical settings. Their breakdown of “look-through” engineering only serves to strengthen the unit’s sci-fi vibe: Eyes-On Glasses use multispectral 3D imaging technology to derive data from invisible spectra and layer it over the user’s natural field of vision. The result? A seamless blend of the digital and physical world that allows nurses to locate veins viable for IV access in no time.

- John Ericson

New Hepatitis C Drug Decreases Treatment Time From a Year to 12 Weeks

Pharmaceutical companies have been racing to deliver safe and effective Hepatitis C drugs, leading to several breakthroughs over the last few months. Though a few are promising, Sovaldi (sofosbuvir) might be the best hope. Sovaldi is the first interferon-free drug approved by the FDA, and it’s a big deal. Current treatments, including those with Olysio, require interferon injections, which come with terrible side effects — including anemia, insomnia, fatigue, depression, and skin rashes — and the chance that patients won’t be able to tolerate them. Sovaldi’s only reported side effects, when taken with the older drug ribavirin, are fatigue and headache. The drug also decreases the duration of treatment from about a year to 12 weeks. Hepatitis C is a chronic liver disease that affects an estimated 3.2 million people, many of whom don’t know they are infected.

- Anthony Rivas

First Mind-Controlled Robotic Leg Dazzles And Breaks Ground

In what was a colossal coup for prosthetics, bionics engineers from the Rehabilitation Institute of Chicago unveiled a groundbreaking development: the world’s first mind-controlled robotic leg. The project, which was partially funded by a $8 million U.S. Army grant, could help leagues of amputee veterans and many more. Building on recent advances with thought-guided bionic arms, nerves leading from the brain to nearby damaged leg muscles were rewired into healthy muscle adjacent to the robotic limb. Sensors from the mechanical leg read what the nerves were saying to guide the prosthetic. "The bionic leg allows me to seamlessly walk up and down stairs and even reposition the prosthetic by thinking about the movement I want to perform," Zac Vawter, the first and only recipient, said in a statement. "This is a huge milestone for me and for all leg amputees." A year earlier, Vawter demoed the leg by climbing all 103 floors of Chicago's Willis Tower. The project took four years to complete, and, after much anticipation, the findings were published in September’s New England Journal of Medicine.

- Nsikan Akpan

A (Very Strange) Cure for Baldness

This past year, scientists at Columbia University unveiled a new technique for hair regeneration using human dermal papilla cells and circumcised foreskin.

The cells — obtained from seven men who were undergoing hair transplants at the time — were first grown in a hanging drop tissue culture, and then injected into foreskin-made grafts on mice. Since foreskin has zero hair follicles of its own, the researchers believed using foreskin grafts would prevent any confusion between the transplanted human hair follicles and the native mice hair follicles.

The result? The human hair follicles transplanted onto the backs of mice sprouted, and led to a substantial boost in hair growth. Although the technique hasn’t yet been tested on human heads, these findings highlight the possibility that transplanted skin could not only create an environment for new hair follicles, but also could slow down the loss of hair follicles and stimulate the growth of existing hairs. In other words, it could be a cure-all for the full range of hair loss, from receding hairlines in men to thinning hair in women.

- by Liz Borreli

Optogenetics Shine A Light On the Brain

Our understanding of the most complex human organ, the brain, depends heavily on our abilities to manipulate samples. In animal studies, researchers use tools to stimulate or lesion certain brain regions to understand emotion, memory, perception, and more. But neuroscientists have long dreamt of a more elegant and precise way of turning nerves on and off, which is why a technique known as optogenetics has garnered a lot of excitement of late.

This new technique involves a light-sensitive gene, known as channelrhodopsin, which scientists can, for example, insert in a single type of neuron in mice. When the brain is exposed to light, these neurons that have this gene activate — or inactivate, depending on the experiment. This light-sensitive neuronal on/off switch allows for a more nuanced look at the “black box of cell signaling” and has already provided insight about OCD behavior and drug-taking.

- Peter Sergo

The “Garbage Truck Brain” Hypothesis Explains Why Animals Need To Sleep

Sleep may seem like a flaw in evolution, considering how vulnerable we are when we do it. But scientists this year made a landmark finding into the odd-seeming habit, namely that, when we sleep our brain performs a kind of flushing of waste material. The purpose is to prevent the build-up of destructive plaques, which can lead to Alzheimer’s disease. Each night, the stores of sensory data we’ve accumulated over the course of the day must be removed. Like the garbage truck that rumbles freely through empty city streets at night, the brain demands that neural processes remain traffic-free if it’s to perform its nightly shift. So we sleep. "You can think of it like having a house party,” said Dr. Maiken Nedergaard, lead author of the breakthrough study. “You can either entertain the guests or clean up the house, but you can't really do both at the same time." The study, for the first time ever, offers a neurochemical explanation for sleep.

- Chris Weller

Phobias Can Be Passed From Generation To Generation

As we move deeper into the 21st century, the age-old debate of nature vs. nurture is beginning to become stale. Science has moved on, positing the more holistic idea that nature is nurture and vice verse — that your experiences can actually change your genetic makeup and vice versa. In perhaps the most compelling argument yet for what scientists call “epigenetics,” researchers at Emory University in Atlanta were able to prove that mice could pass down a fear that they learned in their lifetime.

In the study, the scientists conditioned one generation of mice to develop a new fear of the smell of cherry blossoms. Those fearful mice then gave birth to a new generation who, it turned out, retained the cherry blossom phobia. The researchers believe that this line of inquiry could eventually explain how neuropsychiatric disorders — phobias, anxiety, and post-traumatic stress disorder, for example — can develop in one generation’s lifetime and then be passed down to the next.

- Elijah Wolfson

How To Print Your Own Body Parts

The ability to generate new body parts from scratch seems like something out of Star Trek or The Jetson’s, but it’s not. This past year saw an explosion in the medical uses of 3D printing technology. Early in 2013, American neurosurgeons created a polymer skull implant to replace approximately 75 percent of a patient’s skull. A baby who had a collapsed lung benefited from 3D technology as engineers developed a splint to support the baby’s narrow airways, ultimately saving her life. At the Third Annual Cell Therapy Bioprocessing Conference a San Diego company developed and presented the world’s first 3D human liver. And a loving father, Paul McCathy, set out to make a prosthetic left hand for his son who was without fingers — ultimately, he made one using only $10 worth of materials.

- Sabrina Bachai

New HIV Vaccine Proves Successful In Phase 1 Human Trial

Developing a working vaccine for HIV, the virus that causes AIDS, has been a top priority of public health officials for decades. This year, scientists tested out the first-ever HIV vaccine based on a genetically modified killed-whole HIV-1, or a ‘dead’ version of the virus. Cells are infected with this genetically modified ‘dead’ HIV, which then triggers an immune response. The results were encouraging; the vaccine was proven safe during a Phase 1 clinical trial completed this August.

After volunteers received the vaccine, researchers observed them again every few weeks for a physical exam as well as a clinical chemistry, hematology, and urinalysis. They found no serious adverse effects, meaning the vaccine is quite safe. They also found a boost in the production of a particular antibody that fights against HIV viruses. This vaccine may be of importance down the road, as it is similar to the killed-whole vaccines for polio, influenza, and hepatitis A, which are already successfully in use.

- Lecia Bushak

The Affordable Care Act Changes The Public Health Landscape

It’s safe to say that no piece of legislation has drawn more attention this year than the Affordable Care Act, both politically and in the media. The Act, which has been nicknamed “Obamacare,” was signed into law by President Barack Obama in 2010. One of the key provisions of the law — health care marketplaces aimed to provide quality, affordable medical coverage to millions of uninsured Americans — debuted to a rocky start in October, with glitches and crashes plaguing the heavily promoted site and preventing a number of potential registrants from successfully signing up for coverage. Since October, though, the site has been fixed and is reportedly ready to handle up to 800,000 visitors a day. If successful, the Affordable Care Act could be the most profound health care legislation of a generation in the U.S., revolutionizing the way we get our insurance coverage and giving millions of previously uninsured Americans an opportunity for coverage as early as January 2014.

- Nadia-Elysse Harris

Marijuana Cures Crohn’s Disease

2013 saw no shortage of studies advocating medical marijuana as an effective treatment for symptoms of glaucoma, epilepsy, HIV/AIDS, certain types of cancer, and other conditions. One stood out: Researchers from Meir Medical Center and Sackler Faculty of Medicine at Tel Aviv University concluded a landmark study earlier this year in which patients with Crohn’s Disease achieved “complete remission” after starting a daily cannabis regimen.

As opposed to other controlled trials that explored marijuana’s remedial effect on cancer or AIDS, this study published in the journal Clinical Gastroenterology and Hepatology ended with total remission of Crohn’s symptoms in five of the 21 patients used for the sample. The research team from Israel attributed this outcome to cannabis’ anti-inflammatory components, also known as Cannabinoids. Now researchers are focused on the anti-inflammatory mechanism in marijuana that facilitates the release of inflammatory agents including histamine and serotonin.

- Justin Caba