WHAT IS NANOBIOTECHNOLOGY?
Nanobiotechnology is a young and rapidly evolving field of research in nanoscience and it is an interdisciplinary area which complies advances in Science and Engineering. Nanobiotechnology is a field that concerns the utilization of biological system optimized through evolution, such as cells, cellular components, nucleic acid, and proteins to facilitate functional nanostructured and mesoscopic architecture comprised of organic and inorganic materials.
Nano means “one-billionth.” The nanometer is one-billionth of a meter — much too small to see with the naked eye or even with a conventional light microscope. Nanotechnology involves creating and manipulating materials at the nano scale. This is a relatively new area for researchers, with rapidly growing commercial applications. Nanobiotechnology is biotechnology at the nano scale, and it has exciting applications in drug delivery systems, diagnostic medical tests and regenerative medicine.
Nanostructure materials have potentials application in many areas, such as biological detection, controlled drug delivery, low-threshold laser, optical filters, and also sensors.
APPLICATIONS OF NANOBIOTECHNOLOGY
Applications of nanobiotechnology are extremely widespread such as
Nanomedicine is a field of medical science whose applications are increasing more and more thanks to nanorobots and biological machines.At a clinical level, cancer treatment with nanomedicine will consist of the supply of nanorobots to the patient through an injection that will search for cancerous cells while leaving the healthy ones untouched. Patients that will be treated through nanomedicine will not notice the presence of these nanomachines inside them; the only thing that is going to be noticeable is the progressive improvement of their health. Nanobiotechanlogy helps in making vaccines as well.
In the agriculture industry, engineered nanoparticles have been serving as nano carriers, containing herbicides, chemicals, or genes, which target particular plant parts to release their content. Previously nanocapsules containing herbicides have been reported to effectively penetrate through cuticles and tissues, allowing the slow and constant release of the active substances. Likewise, other literature describes that nano-encapsulated slow release of fertilizers has also become a trend to save fertilizer consumption and to minimize environmental pollution through precision farming.
Nanoscale delivery vehicles can
(1) enhance the therapeutic efficacy and minimize adversities associated with available drugs
(2) enable new classes of therapeutics
(3) encourage the re-investigation of pharmaceutically suboptimal but biologically active new molecular entities that were previously considered undevelopable.
4. In vitro diagnostics
Nanotechnology-based sensors (e.g. nanowires, nanotubes, nanoparticles, cantilevers, and micro-/nanoarrays) can enable fast and high throughput detection of disease biomarkers with higher sensitivity and lower sample consumption. Nanotechnology also offers hope for the early detection of viruses, bacteria, and circulating tumor cells, as well as for single cell analysis.
5. In vivo imaging
Targeted imaging nanoprobes (e.g. magnetic nanoparticles, quantum dots, and carbon nanotubes) could provide a faster, less invasive, and more accurate way to diagnose diseases (e.g. cancer) at their earliest stages and monitor disease progression. Some other possible opportunities include reporting in vivo efficacy of therapeutics, tracking nanocarrier biodistribution in the body, and helping surgeons to locate tumors and their margins, identify important adjacent structures, and map sentinel lymph nodes.
6. Therapy techniques
Certain nanomaterials have unique therapeutic properties that differ from conventional drugs, and can, therefore, be directly used to treat diseases. For example, hafnium oxide- and gold-based nanoparticles can greatly enhance X-ray therapy; gold nanoshells/nanorods, carbon nanotubes, magnetic nanoparticles can induce hypothermia to kill cancer cells; and nanocrystalline silver is being used as an antimicrobial agent.
Biocompatible nanomaterials that have optimal mechanical properties can be used as medical implants (e.g. dental restoratives and bone substitutes)†. Nanocoatings or nanostructured surfaces can also improve the biocompatibility and adhesion of biomaterials.
8. Tissue engineering
Nanotechnology can enable the design and fabrication of biocompatible scaffolds at the nanoscale and control the spatiotemporal release of biological factors—resembling native extracellular matrix—to direct cell behaviors, and eventually lead to the creation of implantable tissues.
NANOSYSTEMS IN NATURE
Biological systems often feature natural, functional nanomaterials. The structure of foraminifera (mainly chalk) and viruses
(protein, capsid), the wax crystals covering a lotus or nasturtium leaf, spider and spider-mite silk, the blue hue of tarantulas,the “spatulae” on the bottom of gecko feet, some butterfly wing scales, natural colloids (milk, blood), horny materials (skin, claws, beaks, feathers, horns, hair), paper, cotton, nacre, corals, and even our own bone matrix are all natural organic nanomaterials.
Natural sources of nanoparticles include combustion products forest fires, volcanic ash, ocean spray, and the radioactive decay of radon gas. Natural nanomaterials can also be formed through weathering processes of metal- or anion-containing rocks, as well as at acid mine drainage sites.
A nanoparticle is by definition a particle where all the three dimensions are in nanometer scale. Nanoparticles are known to exist in diverse shapes such as spherical, triangular, cubical, pentagonal, rod-shaped, shells, ellipsoidal and so forth.
Nanoparticles by themselves and when used as building blocks to construct complex nanostructures such as nanochains, nanowires, nanoclusters and nanoaggregates find use in a wide variety of applications in the fields of electronics, chemistry, biotechnology and medicine, just to mention few: For example, gold nanoparticles are being used to enhance electroluminescence and quantum efficiency in organic light emitting diodes palladium and platinum nanoparticles are used as efficient catalysts , glucose sensors are developed based on AgNP and iron oxide NP are used as contrast agents in diagnosing cancer in Magnetic Resonance Imaging (MRI).
Nanoparticles have large surface to volume ratio, thus surface related phenomena/properties are drastically
affected with slight modification of size, shape and surrounding media of nanoparticles. Therefore, the optical properties of desired nanoparticles depending on application can be tuned by generating the nanoparticles of definite size and shape in preferred media and henceforth, develop new effective nanomaterials and nanodevices.
Types of Gold Nanoparticles
In recent years, there has been tremendous interest in using novel solid state nanomaterials for medical and biological applications. The unique physical properties of nanoscale solids (dots or wires) in conjunction with the remarkable recognition capabilities of biomolecules could lead to miniature biological electronics and optical devices including biosensors and probes. We describe below some interesting examples that utilize nanostructured materials conjugated with DNA as novel biosensors.
Sequence specific DNA detection is an important topic because of its application in the diagnosis of pathogenic and genetic diseases. The principle of their detection method relies on oligonucleotide molecules labeled with a thiol group which are attached at one end of the core of a 2.5 nm gold nanoparticle and a fluorophore at the other end. This hybrid construct is found to spontaneously assemble into a constrained arch like conformation on the particle surface. In the assembled state, the fluorophore is quenched by the nanoparticle.
Upon target binding, the conformation opens and the fluorophore leaves the surface because of the structural rigidity of the hybridized double stranded DNA, and fluorescence is restored. This structural change generates a fluorescence signal that is highly sensitive and specific to the target DNA.
Microarrays are a sensitive, specific, miniaturized devices that may be used to detect selected DNA sequences and proteins, or mutated genes associated with human diseases. Several methods have been developed to detect the binding of complementary molecules to microarrays by generating an optical signal. One of the most commonly used molecular labeling methods at present is fluorescence, but it is sophisticated process that requires a lot of work and patience.
Using nanoparticles we can have similar sensitivity and specificity. Nanoparticles are sphere-like biocompatible materials made of inert silica, metal or crystals of a nanometer in size, which are generally coated with a thin gold layer. They may be used as hybridization probes in single nucleotide polymorphism (SNP) screening and to detect biological markers for cancer, infection, and cardiovascular diseases.
Nanotechnology can be used to create nanofibers, nanopatterns and controlled-release nanoparticles with applications in tissue engineering, for mimicking native tissues since biomaterials to be engineered is of nanometre size like extracellular fluids, bone marrow, cardiac tissues etc.
Tissue engineering is an evolving interdisciplinary field integrating biology, engineering, materials science, and medicine, that focuses on the development of biological substitutes to restore, replace, maintain or enhance tissue and organ function.
Over the past few decades, continued progress in this specific field has lead to the creation of implantable tissues, some of which are already used in humans (e.g. skin and cartilage) or have entered clinical trials (e.g. bladder and blood vessels). Nevertheless, most tissue engineering strategies rely on the principle that under appropriate bioreactor conditions, cells seeded or recruited into three-dimensional (3D) biocompatible scaffolds are able to reassemble into functional structures resembling native tissues.
Within tissues, cells are surrounded by extracellular matrix (ECM) which is characterized by a natural web of hierarchically organized nanofibers. This integral nanoarchitecture is important because it provides cell support and directs cell behavior via cell-ECM interactions.
Furthermore, ECM plays a vital role in storing, releasing and activating a wide range of biological factors, along with aiding cell-cell and cell-soluble factor interactions.Thus, the ability to engineer biomaterials that closely emulate the complexity and functionality of ECM is pivotal for successful regeneration of tissues.
Recent advances in nanotechnology, however, have enabled the design and fabrication of biomimetic microenvironment at the nanoscale, providing an analog to native ECM. Notably, these technologies have been applied to create nanotopographic surfaces and nanofeatured scaffolds, and to encapsulate and control the spatiotemporal release of drugs (e.g. growth factors). In turn, these nanodevices offer a means to direct cellular behaviors that range from cell adhesion to gene expression.
It is widely believed that active targeting, through the modification of nanoparticles with ligands, has the potential to enhance the therapeutic efficacy and reduce the side effects relative to conventional therapeutics. While the necessity of targeted delivery depends on various factors (e.g. delivery vehicles, drugs, and diseases), a myriad of important benefits have been demonstrated.
In cancer therapy, the presence of targeting ligands can greatly enhance the retention and cellular uptake of nanoparticles via receptor-mediated endocytosis—even although tumor accumulation is largely determined by the physicochemical properties of nanoparticles. This can then lead to higher intracellular drug concentration and increase therapeutic activity.
Similarly, ligand-mediated targeting is of importance for the transcytosis of nanodrugs across tight epithelial and endothelial barriers (e.g. blood-brain barrier).Additionally, targeted delivery has been applied, in some instances, to combat multidrug resistance (MDR).
Targeted nanoparticle fabrication usually requires multiple steps—biomaterial assembly, ligand coupling/insertion, and purification—and could cause batch-to-batch variation and quality concern. The recent development of single-step synthesis of targeted nanoparticles by self-assembling pre-functionalized biomaterials provides a simple and scalable manufacturing strategy. Another important consideration is targeting ligands.