Nanoneedle
Encyclopedia
Nanoneedles may be conical or tubular needles in the nanometre
size range, made from silicon or boron-nitride with a central bore of sufficient size to allow the passage of large molecules, or solid needles useful in Raman spectroscopy
, light emitting diodes (LED) and laser diodes.
The conical needles can be mounted in arrays and used to deliver any drug or vaccination antigen. In a painless drug delivery procedure, the array is pressed against the skin. The technology was developed by the Israeli company NanoPass Technologies in 2004, and may reduce the volume of antigen required to ensure adequate immunity, as well as creating multiple immune pathways. The procedure was tested on animal models, effectively delivering insulin
and diclofenac
.
In 2005 the Research Institute for Cell Engineering at Japan's National Institute of Advanced Industrial Science and Technology
(AIST) and Tokyo University of Agriculture and Technology
used nanoneedles controlled by an atomic force microscope
(AFM) to penetrate the nucleus of living cells and insert molecules of nucleic acid, proteins or possibly to carry out cell surgery. The technique can accurately establish the position of the needle by monitoring the force exerted. Cells to be used for tracking, diagnosing, and treatment of illness, may be removed from the body and replaced after being injected. The 100 nm diameter needles were cut from silicon AFM tips using focused ion beam etching.
The University of California, Berkeley
in 2008 produced gallium arsenide (GaAs) nanoneedles which emit extremely bright light, though not yet lasers
, when optically pumped
. With a length of 3-4 micrometres, they taper to tips of 2-5 nm across. In addition to optoelectronic devices, the needles will be useful in atomic force microscopy (AFM), and can be easily grown in arrays. Such AFM arrays, besides producing near-atomic resolution images of surfaces, could lead to new forms of data storage by direct manipulation of atoms. The needles may also find a use in tip-enhanced Raman spectroscopy, a process in which molecular energy levels are measured by comparing the frequency of incident light with that of outgoing light. A sharp needle tip allows for a more precise examination of the sample, down perhaps to that of single molecules.
In 2009, researchers at the University of Illinois produced a 50 nm diameter boron-nitride nanoneedle with a thin coating of gold, suitable for biophysical research. Its diameter allows easy penetration of cell walls in order to deliver organic matter or fluorescent quantum dots into the cytoplasm or the nucleus. It may also be used as electrochemical probe or optical biosensor
in a cellular environment.
Research at the department of NanoMedicine and Biomedical Engineering at the University of Texas in 2010 created a new type of nanoneedle using silicon. A solution of hydrogen peroxide
produces porous needles - their porosity is controlled along their length by altering the concentration of peroxide over time. The coloured porous needles are constructed to biodegrade over a predictable period, and have a surface area 120 times that of equivalent solid wires, making them useful as drug-delivery vehicles. Since porous silicon does not harm cells, the needles may also be used to tag cells and monitor chemical reactions.
A note of caution was sounded by Martin A. Philbert, professor of toxicology at the University of Michigan, Ann Arbor. "The ability to manipulate nanometer-scale materials at the molecular level holds the promise of conferring specificity of cellular delivery and the reduction of collateral nuisance injury to neighboring cells. In the context of environmental health, the scientific community will have to pay close attention to those physicochemical properties of engineered nanomaterials that defeat or circumvent normal cellular processes and lend themselves to indiscriminate penetration of biological barriers, tissues, and cellular systems."
Nanometre
A nanometre is a unit of length in the metric system, equal to one billionth of a metre. The name combines the SI prefix nano- with the parent unit name metre .The nanometre is often used to express dimensions on the atomic scale: the diameter...
size range, made from silicon or boron-nitride with a central bore of sufficient size to allow the passage of large molecules, or solid needles useful in Raman spectroscopy
Raman spectroscopy
Raman spectroscopy is a spectroscopic technique used to study vibrational, rotational, and other low-frequency modes in a system.It relies on inelastic scattering, or Raman scattering, of monochromatic light, usually from a laser in the visible, near infrared, or near ultraviolet range...
, light emitting diodes (LED) and laser diodes.
The conical needles can be mounted in arrays and used to deliver any drug or vaccination antigen. In a painless drug delivery procedure, the array is pressed against the skin. The technology was developed by the Israeli company NanoPass Technologies in 2004, and may reduce the volume of antigen required to ensure adequate immunity, as well as creating multiple immune pathways. The procedure was tested on animal models, effectively delivering insulin
Insulin
Insulin is a hormone central to regulating carbohydrate and fat metabolism in the body. Insulin causes cells in the liver, muscle, and fat tissue to take up glucose from the blood, storing it as glycogen in the liver and muscle....
and diclofenac
Diclofenac
Diclofenac is a non-steroidal anti-inflammatory drug taken to reduce inflammation and as an analgesic reducing pain in certain conditions....
.
In 2005 the Research Institute for Cell Engineering at Japan's National Institute of Advanced Industrial Science and Technology
National Institute of Advanced Industrial Science and Technology
The , or AIST, is a Japanese research facility headquartered in Tokyo, and most of the workforce is located in Tsukuba Science City, Ibaraki, and in several cities throughout Japan. The institute is managed to integrate scientific and engineering knowledge to address socio-economic needs...
(AIST) and Tokyo University of Agriculture and Technology
Tokyo University of Agriculture and Technology
Established in 1949 as a national university, , nicknamed "Nōkōdai" or "TUAT", is a research-oriented national university with two campuses, one each located in the cities of Fuchū and Koganei, Tokyo....
used nanoneedles controlled by an atomic force microscope
Atomic force microscope
Atomic force microscopy or scanning force microscopy is a very high-resolution type of scanning probe microscopy, with demonstrated resolution on the order of fractions of a nanometer, more than 1000 times better than the optical diffraction limit...
(AFM) to penetrate the nucleus of living cells and insert molecules of nucleic acid, proteins or possibly to carry out cell surgery. The technique can accurately establish the position of the needle by monitoring the force exerted. Cells to be used for tracking, diagnosing, and treatment of illness, may be removed from the body and replaced after being injected. The 100 nm diameter needles were cut from silicon AFM tips using focused ion beam etching.
The University of California, Berkeley
University of California, Berkeley
The University of California, Berkeley , is a teaching and research university established in 1868 and located in Berkeley, California, USA...
in 2008 produced gallium arsenide (GaAs) nanoneedles which emit extremely bright light, though not yet lasers
Lasing threshold
The lasing threshold is the lowest excitation level at which a laser's output is dominated by stimulated emission rather than by spontaneous emission. Below the threshold, the laser's output power rises slowly with increasing excitation. Above threshold, the slope of power vs. excitation is orders...
, when optically pumped
Optical pumping
Optical pumping is a process in which light is used to raise electrons from a lower energy level in an atom or molecule to a higher one. It is commonly used in laser construction, to pump the active laser medium so as to achieve population inversion...
. With a length of 3-4 micrometres, they taper to tips of 2-5 nm across. In addition to optoelectronic devices, the needles will be useful in atomic force microscopy (AFM), and can be easily grown in arrays. Such AFM arrays, besides producing near-atomic resolution images of surfaces, could lead to new forms of data storage by direct manipulation of atoms. The needles may also find a use in tip-enhanced Raman spectroscopy, a process in which molecular energy levels are measured by comparing the frequency of incident light with that of outgoing light. A sharp needle tip allows for a more precise examination of the sample, down perhaps to that of single molecules.
In 2009, researchers at the University of Illinois produced a 50 nm diameter boron-nitride nanoneedle with a thin coating of gold, suitable for biophysical research. Its diameter allows easy penetration of cell walls in order to deliver organic matter or fluorescent quantum dots into the cytoplasm or the nucleus. It may also be used as electrochemical probe or optical biosensor
Biosensor
A biosensor is an analytical device for the detection of an analyte that combines a biological component with a physicochemical detector component.It consists of 3 parts:* the sensitive biological element A biosensor is an analytical device for the detection of an analyte that combines a biological...
in a cellular environment.
Research at the department of NanoMedicine and Biomedical Engineering at the University of Texas in 2010 created a new type of nanoneedle using silicon. A solution of hydrogen peroxide
Hydrogen peroxide
Hydrogen peroxide is the simplest peroxide and an oxidizer. Hydrogen peroxide is a clear liquid, slightly more viscous than water. In dilute solution, it appears colorless. With its oxidizing properties, hydrogen peroxide is often used as a bleach or cleaning agent...
produces porous needles - their porosity is controlled along their length by altering the concentration of peroxide over time. The coloured porous needles are constructed to biodegrade over a predictable period, and have a surface area 120 times that of equivalent solid wires, making them useful as drug-delivery vehicles. Since porous silicon does not harm cells, the needles may also be used to tag cells and monitor chemical reactions.
A note of caution was sounded by Martin A. Philbert, professor of toxicology at the University of Michigan, Ann Arbor. "The ability to manipulate nanometer-scale materials at the molecular level holds the promise of conferring specificity of cellular delivery and the reduction of collateral nuisance injury to neighboring cells. In the context of environmental health, the scientific community will have to pay close attention to those physicochemical properties of engineered nanomaterials that defeat or circumvent normal cellular processes and lend themselves to indiscriminate penetration of biological barriers, tissues, and cellular systems."