Nanotechnology bears a multitude of possibilities to systematically and specifically treat many well-characterized and currently untreatable diseases. Despite this, there exist multiple barriers to its development including challenges related to delivery in the human body.
Justin Hanes, a professor of Chemical and Biomolecular Engineering at Johns Hopkins University, highlighted some of the exciting advances that his laboratory has developed to overcoming these challenges. According to Hanes, one of the primary functions of nanobiotechnology is to enable a therapy to be delivered to a specific location and only remain there for as long as it is needed. He likened this idea to applying weed poison to a rose garden. You only want to apply a little bit of poison to a targeted area, not flood the whole garden. Unfortunately conventional cancer chemotherapy is like flooding the garden, but only 1 percent of the drug reaches the tumor. Hanes stated the goal of his work is to flip that so that all but 1 percent of the drug makes it to the site of delivery.
Johns Hopkins researchers report they are one step closer to having a drug-delivery system flexible enough to overcome some key challenges posed by brain cancer and perhaps other maladies affecting that organ. In a report published online Aug. 29 in Science Translational Medicine, the Johns Hopkins team says its bioengineers have designed nanoparticles that can safely and predictably infiltrate deep into the brain when tested in rodent and human tissue.
“We are pleased to have found a way to prevent drug-embedded particles from sticking to their surroundings so that they can spread once they are in the brain,” said Justin Hanes, Lewis J. Ort Professor of Ophthalmology and project leader in the Johns Hopkins Center of Cancer Nanotechnology Excellence.
Standard protocols following the removal of brain tumors include chemotherapy directly applied to the surgical site to kill any cancer cells left behind. This method, however, is only partially effective because it is hard to administer a dose of chemotherapy high enough to sufficiently penetrate the tissue to be effective and low enough to be safe for the patient and healthy tissue. Furthermore, previous versions of drug-loaded nanoparticles typically adhere to the surgical site and do not penetrate into the tissue.
The brain is a notoriously difficult organ to treat, but Johns Hopkins researchers report they are one step closer to having a drug-delivery system flexible enough to overcome some key challenges posed by brain cancer and perhaps other maladies affecting that organ.
In a report published online on August 29 in Science Translational Medicine, the Johns Hopkins team says its bioengineers have designed nanoparticles that can safely and predictably infiltrate deep into the brain when tested in rodent and human tissue.
“We are pleased to have found a way to prevent drug-embedded particles from sticking to their surroundings so that they can spread once they are in the brain,” says Justin Hanes, Ph.D., Lewis J. Ort Professor of Ophthalmology, with secondary appointments in chemical and biomolecular engineering, biomedical engineering, oncology, neurological surgery and environmental health sciences, and director of the Johns Hopkins Center for Nanomedicine.
“Would you poison the entire garden to kill one weed?” asked Justin Hanes at the opening of his talk at the 2012 Johns Hopkins annual NanoBio Symposium. “Unfortunately, that is how most chemotherapy works today.” Hanes is a professor of ophthalmology at Johns Hopkins School of Medicine and an affiliated faculty member of the Institute for NanoBioTechnology.
On average, less than one percent of any chemotherapy cancer treatment will go to a patient’s tumor. The remaining 99 percent circulates through the rest of the patient’s body, kills healthy cells unnecessarily, and causes often unbearable side effects. This alarming statistic has led Hanes and his team to focus on targeted, chemotherapeutic drug delivery using nanoparticles.
Hanes explained that nanoparticles are ideal in cancer treatment because tumors form new blood vessels within themselves to be able to receive nutrients, and these tumor-associated blood vessels are leaky. Thin, leaky blood vessel walls are ideal for drug-loaded nanoparticles, which are on the order of 1-100 nanometers in diameter, to break through to reach tumor cells. The ultimate goal of nanoparticle drug delivery for cancer is to synthesize bio-targeted particles that provide localized delivery straight to the tumor alone, improving drug effectiveness and reducing undesirable side effects.
Sisters Kim Alkire and Marlee, Cherie , and Karen Ort were invited to Wilmer this August to meet Justin Hanes, Ph.D., the new Lewis J. Ort Professor and Director of the Center for Nanomedicine; for a special champagne toast and tour of the Smith Building. Dr. Hanes is working with other Wilmer investigators to focus the power of nanotechnology on creating new drug and gene therapies for patients with vision disorders, including those that affect the back of the eye, such as age-related macular degeneration; and those that affect the cornea, such as Fuch’s dystrophy.
Researchers have created biodegradable ultra tiny, nanosized particles that can easily slip through the body’s sticky and viscous mucus secretions to deliver a sustained-release medication cargo.
The interdisciplinary team of researchers led by Justin Hanes, Ph.D., professor and director of the Johns Hopkins Center for Nanomedicine, developed the nanoparticles, which degrade over time into harmless components. The team believes they could one day carry life-saving drugs to patients suffering from dozens of health conditions, including cancer.
The new technology is expected to help patients suffering from diseases, such as cystic fibrosis, that affect mucus-lined surfaces of the body, but the nanoparticles also could be used to help treat lung and cervical cancers, says Hanes. He is working with Chien-Fu Hung, Ph.D., and T.C. Wu, M.D., Ph.D., M.P.H., to develop their use in cancer treatment. “Chemotherapy is typically given to the whole body and has many undesired side effects,” he said. “For example, if drugs are encapsulated in these nanoparticles and inhaled directly into the lungs of lung cancer patients, drugs may reach lung tumors more effectively, and improved outcomes may be achieved, especially for patients diagnosed with early stage non–small cell lung cancer.”