Where success in almost any field is had by thinking big and seeing the larger picture, the future of medical treatment seems to be in thinking small. Really small—on the molecular scale.
Nanomedicine is changing the way doctors combat disease. Prior to the advent of molecular technology, medicine took the “carpet-bombing” approach, injecting a drug into the general area of the diseased tissue or bombarding it with radiation.
Such wide-area targeting often causes collateral damage to surrounding healthy tissue that happens to be in the way or too close for its own good.
But with the help of new drugs and materials, including the recently discovered wonder material called graphene, medicines are being developed that function like smart-bombs, working their way harmlessly through the bloodstream to attack only those specific tissues that need to be cured or destroyed.
A whole new world of nanomedicine is opening up.
Since electrical circuitry is little more than the controlled flow of electrons along determined pathways, nanomedicine is exploring ways of using organic molecules to create bio-circuits that can navigate to any part of the human body and deploy a cargo of medicines.
These “smart-pills” can be programmed to reach specific tissues by incorporating molecules that recognize specific proteins on the surface of diseased cells—kind of like a narcotics-sniffing dog.
They can even be coated with “nano-armor” that protects them from the body’s immune system so they won’t be attacked by the patient’s own bio-defenses.
This specialized “packaging” around drugs and medicines has opened the way for previously unusable drugs to finally be used safely. As Dr. Juliana Chan, adjunct assistant professor at the Nanyang Technological University (NTU) in Singapore, explains to the South China Morning Post:
“Drugs with poor profiles that were routinely discarded, for being too hydrophobic [water-repellent] for example, and previously had poor bioavailability can now be encapsulated in nanoparticles to improve their solubility and pharmacokinetic profiles.”
Once they locate their targets, these programmable microscopic saboteurs bind themselves to the infected tissue and deliver their drugs only to the desired cells, without harming any surrounding healthy tissue. They can also release their medicines at a predetermined rate to apply just the right amount at just the right flow.
“Anything you can do to improve targeting of tumors rather than normal tissue - whether that is through an armed antibody or nanoparticle approach - increases the chance of success.”
Nanoparticles are also being designed to improve diagnostics. Particles made of polymers, gold, and even graphene (a carbon material that conducts electrical signals better than all other materials) are being developed to improve scans, X-rays, and other diagnostic imagery.
Yet nanomedicine is exploring not just how to destroy harmful tissues, but also how to repair and reconstruct needed tissues.
Professor So Kwok-fai of the Hong Kong University, in collaboration with Boston’s MIT, has developed a nanoparticle to help repair damaged nerves. When these amino-acid-based particles absorb blood, they reassemble themselves into a porous mesh that spans openings or gaps within the tissue. Over time, new cells can grow across these molecular frames, and the tissue becomes whole again.
As an unexpected benefit, it was recently discovered that these particle-delivered meshes or frames helped stop bleeding by providing a kind of dam-like obstruction to which blood cells could cling, facilitating coagulation.
The benefits in controlling bleeding during surgery and in speeding the healing process after surgery are astounding. “Normally it would take more than 90 seconds for platelets to amass at the site of the wound, form a blood clot and stop the bleeding,” explains Professor So to the South China Morning Post. “But the application of the nanomaterial was able to stop the bleeding within 15 seconds.”
In a parallel research program at the Hong Kong University Department of Surgery, Dr. Kenneth Wong is applying silver nanoparticles to skin burns, surgical wounds, and bone fractures to assist in cell regeneration and repair.
These silver nanoparticles have been shown to stimulate more rapid cell growth and division to close wounds, and they are being tested as a coating agent on wound dressings.
Companies on the Frontlines
Two companies to watch in this rapidly advancing field of “smart-particle” nanomedicine are AstraZeneca PLC (NYSE: AZN) and Bind Therapeutics.
Bind Therapeutics introduces itself at its website as “a clinical-stage biopharmaceutical company developing a new class of highly selective targeted and programmable therapeutics called Accurins™. We seek to significantly improve patients' lives and treat disease in a powerful new way by designing Accurins that selectively target and accumulate at the site of disease, dramatically enhancing efficacy while minimizing effects on healthy tissues.”
The company’s proprietary technology was developed by Professors Robert Langer, David H. Koch Institute Professor of the Massachusetts Institute of Technology (MIT), and Omid Farokhzad, Associate Professor of Harvard Medical School.
The team has attracted the attention and support of several deep-pocketed investors, including Polaris Partners, Flagship Ventures, ARCH Venture Partners, NanoDimension, DHK Investments, EndeavourVision, and Rusnano.
AstraZeneca can now also be added to that list of investors for its recent development and commercialisation agreement with Bind for cancer nanomedicines. From the press release:
“AstraZeneca and BIND Therapeutics announced today that they have entered into a strategic collaboration to develop and commercialise an Accurin™, a targeted and programmable cancer nanomedicine from BIND’s Medicinal Nanoengineering platform, based on a molecularly targeted kinase inhibitor developed and owned by AstraZeneca.”
Though Bind Therapeutics is still a privately held company at this time, AstraZeneca shares are currently trading at around $52 a share.
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