Penicillin. Hailed as the world's first miracle drug because of its ability to cure people of many once-fatal bacterial infections, may be one of the best-known medical breakthroughs of all time. It's almost impossible to imagine a time before antibiotics were discovered and dying from an infected scratch was commonplace.

Current medical innovations are no less impressive. Today, infertile couples can conceive; organs can be transplanted and vaccines can halt deadly epidemics. Thanks to medical findings over the years, the main causes of death today are "diseases of old age," such as heart disease and cancer.

Here's a roundup of fascinating breakthroughs from the past few years.

1. Reprogramming cells to create stem cell without embryos.

In October 2012, two scientists, John B. Gurdon of England and Shinya Yamanaka of Tokyo, were awarded the Nobel Prize in Physiology or Medicine for their regenerative medicine discoveries. The result of their work is that cells can be generated without embryos. Using tissue generated from the body's own cells has numerous implications for degenerative diseases and gives scientists a new means of tracking the genesis of disease. Another bonus: creating stem cells in this manner has less ethical complexities.

2. Innovative heart pumps for patients that couldn't be helped in the past.

Heart medications can keep the heart beating but can't prevent other problems, says Eugene Storozynsky, MD, PhD, University of Rochester Medical Center, School of Medicine and Dentistry. He explains: "The vast majority of patients with heart conditions today may eventually develop progressive heart failure, despite being on good medication. That's because although the medicines are working, they don't always prevent the heart from weakening. Over time the heart may enlarge in size to compensate for the weakness. As it does that, the heart becomes less efficient at pumping."

Thanks to the current generation of heart imaging devices doctor are better able to monitor patients and prevent some of them from developing heart failure.

Miniature mechanical heart pumps surgically implanted within the chest or those with magnetically levitated components may soon be available for patients in the end stages of heart disease. "Since the internal components are magnetically levitated there are no working parts that can wear down. Today, it's possible that patients who weren't good candidates for mechanical heart pumps in the past may have their lives extended by receiving these types of pumps," Dr. Storozynsky explains. 

3. A pill that slows aging.

Longevity researchers working on an anti-aging drug may extend healthy lifespans, too. In a discovery Science magazine called one of the top medical breakthroughs of 2011, researchers from the Mayo Clinic published results showing they could delay the onset of many age-related diseases in mice by killing off the rodents' senescent cells. (Senescent cells stop dividing and accumulate during aging. Once thought to be dormant, it turns out they may be fueling many diseases that typically affect older people.)

When working with mice bred to age prematurely, the scientists found that exposing them to a synthetic drug that attacked the senescent cells cut down on muscle loss, cataracts, skin thinning and other signs of aging. Stay tuned for clinical trials on humans expected in the near future. Harvard University is also using mice to experiment with telomeres—the structures at the tips of chromosomes. When researchers successfully used gene therapy to extend the telomeres in mice, cognitive function improved significantly-the mind of what can be likened to an 80-year-old person, had the mental acuteness of someone middle-aged.

4. Advances in fetal medicine making it safer to test for genetic abnormalities during pregnancy.

The American Congress of Obstetricians and Gynecologists currently recommend prenatal screening for Down syndrome for all pregnant women, regardless of age. A new, non-invasive test makes it possible to collect fetal DNA from the mother's blood stream—rather than the umbilical chord—and can be conducted earlier in the pregnancy (at 10 weeks instead of 19 weeks when amniocentesis tests are typically performed). Standard tests such as chorionic villus sampling (CVS) and amniocentesis are 90 percent accurate but carry a small risk of miscarriage. Ethical issues aside, more knowledge about fetal health could help women and doctors anticipate a risky birth or better prepare for treatable health problems that aren't currently diagnosed until after birth.

5. Slowing the progression of Alzheimer's disease.

Five million Americans currently have Alzheimer's, a type of dementia that causes problems with memory, thinking and behavior. While there is no known cure for the disease (which is not a normal consequence of aging), Alzheimer's advocates and experts are encouraged by the results of recent testing showing medications, such as Solanezumab. The medicine appears to clear abnormal proteins called amyloids from the brain slowing the mental decline in patients in the early stages of the disease. This is significant because many scientists believe that if the right drug is given to patients before symptoms appear, it may be possible to head off the illness in much the same way that statin drugs avert cardiovascular problems.

6. Reversing and preventing blindness.

Researchers at the University of Utah School of Medicine have made tremendous strides in ophthalmology using drugs that activate a protein called Robo4. Abnormal blood vessel growth and leakage are primary factors contributing to two leading causes of blindness: age-related macular degeneration (AMD) and diabetic retinopathy. When scientists used Robo4 on mice models with the ocular diseases, blood vessel growth was inhibited and leakage prevented. Using Robo4 may go beyond diseases of the eye and have important implications for other diseases involving inflammation and blood vessels.