July 3, 2014 12:00 am JST

Taking the tiny road to personalized medicine

TEJRAJ M. AMINABHAVI

Molecular biologists are working hard to unravel complex diseases -- cancer, heart disease, neurological disorders. Recently, much research has focused on nanotechnology and biotechnology as a way to develop personalized medicine and treat these diseases.

     One key to success will be "nanobiotechnology," the fusion of nanotechnology and biotechnology. This field promises new biotech treatments, particularly pharmaceuticals, that are more effective than conventional medicines and traditional methods of drug delivery.

Small is beautiful

The human body is made up of roughly 60 trillion cells, each one carrying a copy of the same DNA. Genes, which encode around 100,000 different life-sustaining proteins, are scattered through the DNA. Living cells have hundreds of "nanomachines" carrying out biological functions on a tiny scale.

     Scientists are using their understanding of molecular biology at the nanometer (DNA, RNA and proteins) to micrometer scale (cells) to manipulate or synthesize these molecules and understand life processes at the most basic level. One example is the creation of unique genetic sequences -- also known as recombinant DNA -- to engineer proteins not found in nature.

     Nanobiotechnology is an interdisciplinary science that brings together biologists, chemists, pharmacists and bioengineers. They use biomolecules as building blocks and biosystems as "fabrication equipment" to create bioengineered tools to analyze specific biological systems.

     These tools allow for more precise biological and chemical analysis, and can create technology platforms that will transform the practice of medicine. Imagine artificial biosensors that can detect minute chemical, biological or mechanical changes and transmit this information as needed to help doctors create better treatment regimens.

     In nature, dogs' sharp sense of smell comes from receptors that are sensitive to chemicals at the nanoscale. Certain fish have tiny sensors that can pick up vibrations in water that a human would completely miss. Taking their cue from nature, scientists are creating nanobiosensors to sniff out changes at the cellular level, opening up the new field of "nanomedicine."

On target

One promising area for nanomedicine is drug delivery. Conventional medications are often a blunt instrument; excessive doses can be harmful to humans. But nanoscale drug delivery methods -- nanotubes, nanochannels, nanoparticles, nanopores and nanocapacitors -- bring both conventional medications and new treatments, such as recombinant proteins, vaccines, nucleotides and genes, just where they are needed.

     This precision targeting minimizes side effects through sustained, slow release, making potentially toxic medicines safer to use and opening the door to new types of biotech drugs, including recombinant proteins and peptides. Joint research by the Soniya College of Pharmacy in India, and UT Southwestern Medical Center in Dallas suggests these drug delivery methods can cross the blood-brain barrier, offering hope for early diagnosis of Alzheimer's disease, for example.

     Another potential application is personalized medicine, in which a course of treatment is tailored to the needs of an individual patient. Personalized cancer therapies, for example, are developed based on an understanding of how the disease works at the molecular level. Nanobiotechnology-based biomarkers, molecular diagnostics, and drug delivery systems -- the basic components of personalized medicine -- are used in treatment. Tools include quantum dots, gold nanoparticles, molecular imaging diagnostic tools and "theranostics" -- which combines therapeutics with diagnosis.

     Overcoming limitations in current diagnostic techniques will depend on nanomedicine developing more precise ways of detecting molecules such as nucleic acids and proteins at relatively low concentrations. Nanomedicine will minimize damage to the body by using more sensitive nanoparticles in diagnosis and treatment.

     Tools will include microarrays and "lab-on-a-chip" devices that can detect gene expression or tiny alterations in DNA. The devices work by printing or attaching DNA or RNA strands and proteins onto the chip. They can carry laboratory functions in a space measuring a few millimeters or centimeters across, detecting viruses or bacteria, for example, or extracting DNA from a blood sample.

Future benefits

Current advances in molecular biology, genetics and nanomedicine allow more accurate diagnosis of disease using the powerful new techniques of nanobiotechnology. They will also fight deadly diseases and help solve the puzzle of conditions that are not yet understood. These developments are an important step toward the type of personalized medicine that will have a high impact on human health.

     Nanobiotechnology is a 21st-century tool that uses biosensors, bioelectronics and new materials to develop more effective approaches to diagnosis and treatment. This burgeoning field will employ nanoscale materials and devices that will become an integral part of medical practice over the next decade to realize the promise of personalized medicine.

Tejraj M. Aminabhavi is emeritus professor and research director at Soniya College of Pharmacy, Dharwad, India.