ASU Biophysicists Demonstrate Carbon Nanotubes' Potential For High-Speed Genetic Sequencing

 In the current issue of Science, Stuart Lindsay, director of Arizona State University’s Center for Single Molecule Biophysics at the Biodesign Institute, along with his colleagues, demonstrates the potential of a new DNA sequencing method in which a single-stranded ribbon of DNA is threaded through a carbon nanotube.

Credit: The Biodesign Institute at Arizona State University.

Faster sequencing of DNA holds enormous potential for biology and medicine, particularly for personalized diagnosis and customized treatment based on each individual's genomic makeup. At present however, sequencing technology remains cumbersome and cost prohibitive for most clinical applications, though this may be changing, thanks to a range of innovative new techniques.  

 In the current issue of Science, Stuart Lindsay, director of Arizona State University's Center for Single Molecule Biophysics at the Biodesign Institute, along with his colleagues, demonstrates the potential of one such method in which a single-stranded ribbon of DNA is threaded through a carbon nanotube, producing voltage spikes that provide information about the passage of DNA bases as they pass through the tube—a process known as translocation. 

 Carbon nanotubes are versatile, cylindrical structures used in nanotechnology, electronics, optics and other fields of materials science. They are composed of carbon allotropes—varied arrangements of carbon atoms, exhibiting unique properties of strength and electrical conductivity. 

Traditional methods for reading the genetic script, made up of four nucleotide bases, adenine, thymine, cytosine and guanine (labeled A,T,C,&G), typically rely on shredding the DNA molecule into hundreds of thousands of pieces, reading these abbreviated sections and finally, reconstructing the full genetic sequence with the aid of massive computing power. A decade ago, the first human genome—a sequence of over 3 billion chemical base pairs—was successfully decoded, in a biological tour de force. The undertaking required around 11 years of painstaking effort at a cost of $1 billion dollars. In addition to the laboriousness of existing techniques, accuracy is compromised, with errors accumulating in proportion to the number of fragments to be read.  

A new strategy involves the use of nanopores—orifices of molecular diameter that connect two fluid reservoirs. A constant voltage can be applied between two electrodes located at either end of the nanopore , inducing an ionic current to flow through the length of the nanopore's enclosed channel. At this scale, the passage of even a single molecule generates a detectable change in the flow of ionic current through the pore. This current is then electronically amplified and measured. Only fairly recently have state of the art micro-manufacturing techniques enabled researchers to construct nanopores at the scale of individual molecules, opening up many new possibilities for single-molecule manipulation and research. 

In the current study, single walled carbon nanotubes, 1-2 nm in diameter, were used for the conducting channels. When a current was induced through the nanotube, segments of single-stranded DNA (known as oligomeres) made up of either 60 or 120 nucleotides, were drawn into the opening of the nanotube and translocated from the anode side of the nanotube to the output cathode side, due to the negative charge carried by the DNA molecule. The velocity of DNA translocation is dependent on both the nucleotide structure and molecular weight of the DNA sample. 

The carbon nanotubes were grown on an oxidized silicon wafer. Results indicate that among the successfully formed nanotubes—those fully opened and without leakage along their length—a sharp spike in electrical activity is detected during the process of DNA translocation. Further, reversing the bias of the electrodes causes the current spikes to disappear; restoring the original bias caused the spikes to reappear.

Lindsay stresses that the transient current pulses, each containing roughly 10x7charges, represent an enormous amplification of the translocated charge. A technique known as quantitative polymerase chain reaction (qPCR) was used to verify that the particular carbon nanotubes displaying these anomalously sharp current spikes—around 20 percent of the total sample, were indeed those through which DNA translocation had occurred.

The team carried out molecular simulations to try to determine the mechanism for the anomalously large ionic currents detected in the nanotubes. Observation of current-voltage curves registered at varying ionic concentrations showed that ion movement through some of the tubes is very unusual, though understanding the precise mechanism by which DNA translocation gives rise to the observed current spikes will require further modeling. Nevertheless, the characteristic electrical signal of DNA translocation through tubes with high ionic conductance may provide a further refinement in ongoing efforts to apply nanopore technology for rapid DNA sequencing.

Critical to successful rapid sequencing through nanopores is the precise control of DNA translocation. The hope is that genetic reading can be significantly accelerated, while still allowing enough time for DNA bases to be identified by electrical current traces. Carbon nanotubes provide an attractive alternative, making the control of nanopore characteristics easier and more reliable.

If the process can be perfected, Lindsay emphasizes, DNA sequencing could be carried out thousands of times faster than through existing methods, at a fraction of the cost. Realizing the one-patient-one-genome goal of personalized medicine would provide essential diagnostic information and help pioneer individualized treatments for a wide range of diseases. 

To see Biodesign Institute at Arizona State University scientist Dr. Stuart Lindsay explain the potential of a sequencing method in which a single-stranded ribbon of DNA is threaded through a carbon nanotube in a video follow this link: http://www.eurekalert.org/multimedia/pub/19288.php?from=151548

Superior Carbonate Based Catalyst Supports for Carbon Nanotube Production Claimed by Belgian Researchers

Facultes Universitaires Notre-Dame De La Paix (Namur, BE) researchers detail a number of hydroxide and carbonate-based catalyst supports used for manufacturing multiwall carbon nanotubes (MWNT) and single wall carbon nanotubes (SWNT) in U.S. Patent Application 20090325788. The inventors claim the new catalyst supports do not produce large amounts of soot and amorphous carbon along with the carbon nanotubes as do many common catalyst supports now used.  

Inventors Janos B. Nagy, Narasimaiah Nagaraju, Isabelle Willems and Antonio Fonseca prepared carbon nanotubes by the catalytic decomposition of hydrocarbons using a technique called CCVD (Catalytic Carbon Vapor Deposition), carried out in the presence of catalysts to produce both MWNTs and SWNTs. Soot and encapsulated metal nanoparticles are the other by-products. The hydrocarbon can be acetylene, ethylene, butane, propane, ethane, methane or any other gaseous or volatile carbon containing compound. The catalyst, a transition metal, is generally, either pure or dispersed on a support.

The presence of a support for the catalyst affects the activity of the catalysts tremendously in the formation of carbon nanotubes. The selectivity of the catalyst for the production of nanotubes also depends on the type of catalyst support interaction.

The most common supports used to prepare supported catalyst for carbon nanotubes production are oxides i.e., silica, alumina, silica-alumina mixtures, magnesium oxide, calcium oxide, titanium oxide, cerium oxide, zeolites, spinels and graphite. The use of porous materials (i.e., silica, alumina, zeolites, etc.) as supports for catalysts, contaminates the carbon nanotubes produced thereon with a large amount of soot and amorphous carbon, while dissolving the support during the purification of the carbon nanotubes.

The Notre-Dame De La Paix hydroxide and carbonate-based catalyst supports do not present the contamination drawbacks of the catalyst supports of the state of the art.

The carbon nanotubes production on the supported catalyst by CCVD comprises the following steps:

Spreading manually or mechanically an appropriate amount of supported catalyst on a quartz boat to be used as bed for the supported catalyst in the fixed bed reactor. In the case of a moving bed reactor, the supported catalyst is spread continuously or by intermittence mechanically or manually on the moving bed of the reactor.

The reactor, containing the supported catalyst, is either kept initially at the appropriate constant reaction temperature (400-1200.degree. C.), or it is heated to the reaction temperature for an appropriate time of the reaction. Inert or reactant gas(es) can be passed over the supported catalyst during that step.

The pure or diluted hydrocarbon is passed over the supported catalyst at a predetermined temperature. Carbon nanotubes are grown on the supported catalyst as a result of the CCVD reaction. Diluted hydrocarbons are obtained by mixing at least one hydrocarbon with other gases such as nitrogen, argon, helium, hydrogen, CO, etc.

The crude nanotubes, composed of a mixture of carbon nanotubes and spent supported catalyst, is collected either continuously in the case of a moving bed reactor or stepwise in the case of a fixed bed reactor.   Preferably, the carbon nanotubes purification is carried out by dissolving the spent supported catalyst as follows:

Stirring the crude nanotubes in a concentrated basic solution, preferably a concentrated NaOH solution, at a temperature in between 100-250.degree. C. Recovering the solid product by filtration and preferably washing it until a neutral pH is obtained. This first step is not necessary if the catalyst support contains only Mg and/or Ca derivatives.

Stirring the product in a concentrated acidic solution, preferably a concentrated HCl solution, at a temperature in between 0-120.degree. C.

Recovering the solid product (purified carbon nanotubes) by filtration and preferably washing until a neutral pH is obtained.

Finally purified carbon nanotubes are dried by air flow on a filter or by a rotary evaporator or by the use of a vacuum pump or by the use of an oven or a furnace. Preferably, the oven or furnace is heated at temperatures varying from 30.degree. C. to 400.degree. C. in air or from 30.degree. C. to 1200.degree. C. under vacuum or inert atmosphere. 

FIG. 3a represents a low magnification Transmission Electron Microscopy (TEM) image of as made MWNTs, synthesized by acetylene decomposition at 700.degree. C. in a continuous reaction of 60 min, on the supported catalyst SCA2. The catalyst was activated by preheating 10 min in N₂ flow.

 

FIG. 3b represents a higher magnification TEM image of MWNTs synthesized as in FIG. 3a.

FIG. 3c represents a low magnification TEM image of as made carbon fibers, synthesized by acetylene decomposition at 700.degree. C. in a continuous reaction of 60 min, on the supported catalyst SCA63. The catalyst was activated by preheating 10 min in N₂ flow.

FIG. 3d represents a low magnification TEM image of purified SWNTs, in bundles, synthesized by CH₄/H₂ decomposition at 1000.degree. C. for 6 min, on the supported catalyst SCC81. The catalyst was activated by 4 min of in situ preheating from 25 to 1000.degree. C. in a CH₄/H₂ flow.

 

FIG. 4a represents the inner and outer diameter distribution histograms of the MWNTs synthesized as in FIG. 3a. The average inner and outer diameter of the MWNTs was found to be 4.7 and 9.7 nm, respectively. No amorphous carbon is noticed either in the sample or on the walls of the tubes. The tubes are generally turbostratic with some defects in the outer surface.

FIG. 4b represents the number of walls as a function of the inner diameter distribution of the MWNTs synthesized as in FIG. 3a. These MWNTs are obtained by acetylene decomposition at 700.degree. C. in a continuous reaction for 60 min on the supported catalyst SCA2. The supported catalyst was activated by preheating it for 10 min in a flow of N₂. The number of walls of the MWNTs is in the range of 2-26 and the average value is 8.

Samsung Creates Viable RF Nanoswitches with Carbon Nanotubes by Tuning Capacitance of Dialectic Materials

Using a MEMS (Micro Electro Mechanical Systems) manufacturing technique, MEMS RF nanoswitches have been developed by Samsung Electronics scientists, and in addition, practical and commercial nanometer sized RF nanoswitches are on the way to being developed.

FIG. 2 is a perspective schematically showing a RF nanoswitch according to an exemplary embodiment in Samsung’s U.S. Patent 7,638,790

 Samsung Electronics Co., Ltd. (Suwon-si, KR)  researchers have created an RF nanoswitch which easily transmits RF signals through carbon nanotubes, overcoming the problem of signal loss encountered in previous attempts to create nanoswitches for RF signals.  The achievement is detailed in U.S. Patent U.S. Patent 7,638,790.

The Samsung RF nanoswitch includes a first electrode unit connected to one terminal of a driving power supply, a second electrode connected to the other terminal of the driving power supply, and a dielectric material selectively coming into contact with at least one of the first electrode unit and the second electrode, depending on whether or not power is applied from the driving power supply.

Samsung RF Nanoswitch inventors Dong-ha Shim, Kuang-woo Nam, Seok-chul Yun and In-sang Song developed the nanometer-sized subminiature RF nanoswitch which solved the loss in RF signal power experienced in previous attempts to create RF nanoswitches

In prior art RF nanoswitches generated electric resistance of several tens to several hundreds k.OMEGA. at a contact portion between the  carbon nanotube and the drain. Due to such electric resistance, an RF signal could not be transmitted to the drain even if the RF nanoswitch is in the ON state or an increased loss in RF signal is caused even if the RF signal is transmitted. Thus it was difficult to commercialize such an RF nanoswitch

In Samsung RF nanoswitch, the driving power supply is a DC power supply and applies a power to the first electrode unit  and the second electrode  to produce an electrostatic force. On each circuit for connecting the driving power supply, the first electrode unit  and the second electrode  with each other, an inductor  is connected, which has inductance sufficiently high to prevent the transmission of an RF signal to the driving power supply. As the impedance of each circuit connected to the driving power supply is increased by the corresponding inductor, the RF signal could not be transmitted to the driving power supply.

According to the Samsung researchers, by tuning the RF switch capacitance by means of a dielectric material, it is possible to reduce the impedance in the RF nanoswitch in which an increased loss in RF signal is caused due to contact resistance produced by a contact between an existing nanotube and a drain, making it possible to stably transmit an RF signal without any loss. In addition, by tuning the impedance by means of capacitance, it make it possible to commercialize a nanometer-sized subminiature RF nanoswitch.

Chinese Researchers Fire Up First Carbon Nanotube Based Heaters-CNT Wires Prove Superior to Traditional Metal Heating Coils

Heaters based on carbon nanotube wires have been developed by Tsinghua University (Beijing City, CN)  researchers and may be developed for the marketplace by Hon Hai Precision Industry Co., Ltd (Tu-Cheng City, TW).

Carbon nanotube wires used in the heating coil prove to be superior in performance and have a longer life than traditional wire heating coils, according to inventors Chen Feng,  Kai Liu,  Ding Wang, Kai-Li Jiang, Chang-Hong Liu Shou-Shan Fan (Beijing City, CN).  In Tsinghua's and Hon Hai's joint U.S. Patent Application 20090314765, the two organizations reveal both hollow and planar carbon nanotube based fabricated. 

The heating elements include carbon nanotube structures. The carbon nanotube structures include a plurality of carbon nanotubes uniformly distributed therein. The carbon nanotubes can be combined by van der Waals attractive force. The carbon nanotube structure can be a substantially pure structure of the carbon nanotubes, with few impurities. The carbon nanotubes can be used to form many different structures and provide a large specific surface area.

The heat capacity per unit area of the carbon nanotube structure can be less than 2.times.10^-4 J/m²K. Typically, the heat capacity per unit area of the carbon nanotube structure is less than 1.7.times.10^-6 J/m²K. As the heat capacity of the carbon nanotube structure is very low, and the temperature of the heating element  can rise and fall quickly, which makes the heating element have a high heating efficiency and accuracy. 

As the carbon nanotube structure can be substantially pure, the carbon nanotubes are not easily oxidized and the life of the heating element will be relatively long. Further, the carbon nanotubes have a low density, about 1.35 g/cm³, so the heating element is light. As the heat capacity of the carbon nanotube structure is very low, the heating element has a high response heating speed.

As the carbon nanotube has large specific surface area, the carbon nanotube structure with a plurality of carbon nanotubes has large specific surface area. When the specific surface of the carbon nanotube structure is large enough, the carbon nanotube structure is adhesive and can be directly applied to a surface.

A typical heater includes a heating element and at least two electrodes. The heating element is located on the two electrodes. The heating element generates heat when a voltage is applied to it. The heating element is often made of metal such as tungsten. Metals, which have good conductivity, can generate a lot of heat even when a low voltage is applied. However, metals may be easily oxidized, thus the heater element has short life. Furthermore, since metals have a relative high density, metal heating elements are heavy, which limits applications of such a heater. Additionally, metal heating elements are difficult to bend to desired shapes without breaking. 

The carbon nanotube hollow heater includes a hollow supporter, a heating element and at least two electrodes. The least two electrodes electrically connected to the heating element. The hollow supporter defines a hollow space, and the hollow supporter has an inner surface and an outer surface. The heating element is located on the inner surface or the outer surface of the hollow supporter. The heating element comprises at least one carbon nanotube film comprising a plurality of carbon nanotubes, and an angle between a primary alignment direction of the carbon nanotubes and a surface of the carbon nanotube film is 0 degrees to 15 degrees. 

Heaters are configured for generating heat. According to the structures, the heaters can be divided into three types: linear heater, planar heater and hollow heater.

The linear heater has a linear structure, and is a one-dimensional structure. An object to be heated can be wrapped by linear heater when the linear heater is used to heat the object. The linear heater has an advantage of being very small in size and can be used in appropriate applications.

The planar heater has a planar two-dimensional structure. An object to be heated is placed near the planar structure and heated. The planar heater provides a wide planar heating surface and an even heating to an object. The planar heater has been widely used in various applications such as infrared therapeutic instruments, electric heaters, etc.

The hollow heater defines a hollow space therein, and is three-dimensional structure. An object to be heated can be placed in the hollow space in a hollow heater. The hollow heater can apply heat in all directions about an object and will have a high heating efficiency. Hollow heaters have been widely used in various applications.

FIG. 7 is a Scanning Electron Microscope (SEM) image of an untwisted carbon nanotube wire used to form heating coils.

FIG. 8 is a Scanning Electron Microscope (SEM) image of a twisted carbon nanotube wire used to form heating coils for carbon nanotube based heaters.

 
FIG. 9 is an isotropic view of a hollow heater having a carbon nanotube structure.

 

FIG. 14 below  is a flow chart of a method for fabricating the hollow heater

Korean Researchers Set Precedent with Manufacturing Method for Metal/Carbon Nanotube Nano-Composites Using Electroplating

 Image Source: KAIST Patent Application 20070199826, Figure 4.

Korea Advanced Institute of Science and Technology (KAIST) (Daejeon, KR) inventors Yoon-Chul Son, Jung-Joon Yoo and Jin Yu disclose a precedent setting method for manufacturing metal/carbon nanotube nano-composites using electroplating in U.S. Patent Application 20070199826.  The metal/carbon nanotube nano-composite can replace all metal thin film materials capable of being electroplated including semiconductor interconnection material like aluminum, copper, and others.

The KAIST method for manufacturing metal/carbon nanotube nano-composite includes: adding carbon nanotubes and cationic surfactants in metal plating solution including metal or metal salt and performing electroplating in the cathode.  The method for manufacturing metal/carbon nanotube nano-composite using electroplating further comprises: immersing carbon nanotubes in acid solution and filtering the solution and carrying out heat treatment; adding the heat treated carbon nanotubes and cationic surfactants in metal plating solution including metal or metal salt and dispersing the carbon nanotubes.  Then a cathode and an anode are provided in the metal plating solution including the carbon nanotubes and the cationic surfactant, to which current is applied and electroplating is carried out in order to obtain metal/carbon nanotube nano-composite (complex material).

The carbon nanotube has excellent electrical conductivity, thermal conductivity and strength, thus is expected to show more excellent physical properties when combined with specific qualities of specific metals. Therefore, there have been a lot of developments of composites including carbon nanotubes.

Especially, when it comes to forming nano-composite of metal and carbon nanotubes, researches are directed to improving mechanical properties and the nano-composite is mainly made in the form of bulk. The nano-composite in the above form is mainly manufactured via a powder method or a sintering process.

Pure carbon nanotubes are formed at high temperature of 600.about.1000.degree. C. via chemical vapor deposition method deposition method and surface treatment prior to the deposition are important to control the growing direction and speed of the pure carbon nanotube. The carbon nanotube does not constitute densely packed structure to leave empty spaces between carbon nanotubes when it grows, leading to a big problem in replacing the existing metal thin film material. There have been attempts to fill the empty spaces between the carbon nanotubes with SiO₂ etc. to use as semiconductor interconnections. When these interconnections are connected to form some layers, there is no alternative as to a process for the next layer.

There are no precedents of forming metal/carbon nanotube nano-composite in the type of thin film using electroplating until now due to the characteristics of the bar shape structure and no charges of the carbon nanotube. If metal and carbon nanotubes are simultaneously deposited at the same time by electroplating, densely packed structure unlike the growth of pure carbon nanotubes can be obtained and depositions at desired portions in a type of thin film are possible, also. Thus, all the metal thin films including the existing semiconductor metal interconnection can be replaced, improving their electrical, mechanical and thermal physical properties. Moreover, the KIST manufacturing method can be applied without changing the existing semiconductor interconnection process or the surface finishing process of electronic products, thus the present invention has good marketability and practicality.

The manufacturing method for metal/carbon nanotube nano-composite distributes carbon nanotubes at a molecule level, by a system that includes: adding carbon nanotubes and cationic surfactants which is adsorbed on the surface of the carbon nanotube in metal plating solution including metal or metal salt to constitute the plating solution; and completely separating and dispersing individual carbon nanotubes each other and carrying out electroplating.

The cationic surfactant is at least one selected from the group consisting of poly(diallyldimethylammonium chloride, PDMA), cetyltrimethylammonium chloride (CTAC), cetyltrimethylammonium bromide (CTAB), dodecyltrimethylammonium bromide (DTAB), dodecyltrimethylammonium chloride (DTAC), Decylamine, Dodecylamine, Hexadecylamine, Triethylamine, Octylsulfate, sodium salt, Hexylamine and Octadecylamine.

The KAIST method overcomes many prior limitations in manufacturing a metal/carbon nanotube complex material. . The metal/carbon nanotube nano-composite manufactured according KIST’s method can produce metal/carbon nanotube nano-composite in a type of thin film using electroplating, and can replace all metal thin film materials capable of being electroplated including semiconductor interconnection material like aluminum and copper, etc.

The KAIST metal/carbon nanotube nano-composite contrary to the growth of pure carbon nanotubes, grows to thin film with a densely packed structure and can be used without changing the existing process method.  As the metal/carbon nanotube nano-composite has carbon nanotubes uniformly dispersed into a metal matrix, the existing metal thin film is expected to improve the electric, mechanic and thermal physical characteristics.

Arrowhead Research Reports Highlights and Financial Results for 2009, Future Bright for Carbon Nanotubes in 2010

Arrowhead Research Corporation (Pasadena, CA) (NASDAQ: ARWR) reported financial results for its fiscal 2009 fourth quarter and full-year ended September 30, 2009 on December 22^nd.

“Fiscal 2009 marked a period of transition in which we successfully streamlined our business model, significantly reduced our cost structure, and made material advances with our lead subsidiaries,” said Dr. Christopher Anzalone, Arrowhead’s President and CEO. “Our aggressive cost-cutting initiatives that we undertook at the beginning of the year continue to pay-off. We are now a more efficient and flexible company, and have simultaneously retained the means to capitalize on longer-term growth opportunities.

We strengthened our balance sheet through a number of mechanisms, including: securing over $3.7 million in license fees, product sales, and grants; raising $4.1 million of equity capital directly into Calando and Unidym; and, raising $2.8 million directly in Arrowhead via an oversubscribed equity financing transaction. Last week, after the end of fiscal 2009, we raised an additional $3.2 million of equity capital into Arrowhead by selling units of restricted stock and warrants at nearly $0.13 higher than our share price traded on the day the financing closed. With this financing in place, we believe our current cash position is sufficient to advance our existing subsidiaries’ prospects through fiscal 2010.

“We also made key progress with our most advanced subsidiaries, Unidym and Calando. During the fourth quarter, we began selling Unidym’s CNT film into the commercial touch panel market and we are beginning to realize modest revenue contribution from the initial introduction of this product. While still in its early stages of market introduction, this marks a crucial milestone for our Company and signifies early adoption of new technologies in the touch panel industry.

“We have reached an advanced point in Calando’s siRNA Phase I clinical trial. We are seeing exciting results that we believe could drive significant shareholder value in the near-term. A manuscript describing some of the data has been prepared for possible publication in a peer-reviewed scientific journal. While we have little control over the timing of potential publication, we look forward to discussing the data once it is published,” Dr. Anzalone concluded.

FOURTH QUARTER FISCAL 2009 AND RECENT COMPANY HIGHLIGHTS:

Business highlights:

Entered the touch panel market with majority owned Unidym, Inc.’s carbon nanotube (CNT) film;

Increased ownership in Unidym to nearly 80% to capture additional subsidiary value;

Advanced Unidym’s potential future revenue stream through licensing of certain fullerene derivatives patents to Nano-C for use in the growing thin film solar industry;

Secured joint development agreements with leading liquid crystal display (LCD) manufacturers to progress Unidym’s CNT product integration into display devices:

Extended Samsung Electronics Co., Ltd. agreement for CNTs in flexible displays.

Entered into new agreement with a major LCD manufacturer for CNTs in glass-based LCDs.

Enhanced subsidiary Calando Pharmaceuticals, Inc.’s strategic leadership with the addition of Mostafa Analoui, Ph.D., and Bruce D. Given, MD, to its Board of Directors.

Completed consolidation activities to further streamline Unidym and Calando operations and maximize potential for near-term opportunities while conserving cash.

Financial highlights:

Decreased quarterly operating expenses by 68% year-over-year to $3.7 million.

Decreased cash burn by 72% in the fourth quarter of fiscal 2009, compared with the same quarter in the prior fiscal year.

On August 6, 2009, completed an oversubscribed financing transaction that raised gross proceeds of $2.8 million.

On December 11, 2009, completed a private placement for gross proceeds of $3.2 million.

SELECTED FISCAL 2009 FOURTH QUARTER FINANCIAL RESULTS

For the fourth quarter ended September 30, 2009, Arrowhead reported revenues of $203,000, compared with ($60,000) in the same period in 2008. The loss in revenue for the fiscal 2008 period reflects an adjustment across periods in grant revenue.

Total operating expenses for the fourth quarter of fiscal 2009 decreased by 68% to $3.7 million, compared with total operating expenses of $11.5 million for the fourth quarter of fiscal 2008. The significant reduction in operating expenses was a direct result of measures undertaken by management at the beginning of the year to streamline its businesses and better align its cost structure with its capital resources.

Net loss for the fourth quarter of fiscal 2009 was ($3.5) million, or ($0.06) per share based on 51.9 million weighted average shares outstanding. This compares with a net loss of ($8.7) million, or ($0.22) per share based on 40.5 million weighted average shares outstanding, for the fourth quarter of fiscal 2008.

SELECTED FISCAL 2009 FULL-YEAR FINANCIAL RESULTS

For the fiscal year ended September 30, 2009, Arrowhead reported revenues of $3.8 million, compared with $1.3 million for the fiscal year ended September 30, 2008. Net loss for the 2009 fiscal year was ($19.3) million, or ($0.43) per share based on 45.2 million weighted average shares outstanding, compared with a net loss of ($27.1) million, or ($0.69) per share based on 39.2 million weighted average shares outstanding in the 2008 fiscal year.

The Company's net cash used in operations for the 2009 fiscal year was $15.3 million, compared with $27.6 million in the 2008 fiscal year. Arrowhead’s consolidated cash flows included approximately $2.5 million raised from outside investors through a note offering by Calando and the sale of $2.0 million of newly issued Unidym C-1 shares to TEL Ventures in the first quarter of fiscal 2009. Additionally, Unidym realized a $0.7 million gain through the sale of its equity interest in Ensysce BioSciences, Inc.

As of September 30, 2009, Arrowhead had cash and cash equivalents of $2.0 million and stockholders' equity of $4.9 million. Subsequent to the close of the 2009 fiscal year, Arrowhead sold an aggregate of 5.1 million units comprised of common stock and warrants in private placement transactions with accredited investors for gross proceeds of $3.2 million.

Fiscal 2010 Outlook

“We have reached an important inflection point that we believe could increase shareholder value in 2010 and beyond,” said Dr. Anzalone. “Our near-term goals for 2010 will be focused on gaining market traction with Unidym’s CNTs in the large touch panel market where we see considerable opportunity to drive value and growth. We’ve made exceptional progress on this front as evidenced by our initial product introduction, as well as our continued and new partnerships with leading LCD manufacturers.

We also plan to continue to enroll patients in Calando’s clinical Phase I escalating dose trial and believe that our initial data set holds important implications for the future of RNAi therapeutics. In-line with our strategy to maximize revenue opportunity with minimal expenditure, we believe that as this trial proceeds, we will be well-positioned to monetize the value of Calando’s delivery system and therapeutic drug candidate through potential partnering, licensing or M&A activities.

“In addition, after a year-long suspension of efforts instituted to preserve capital, we have begun exploring new opportunities in the nanobiotech space. Given where Calando and Unidym are in their development, we are beginning to slowly shift from our defensive posture toward becoming more opportunistic. We continue to keep a close eye on costs and plan to accelerate into this transition once we have better visibility into possible future liquidity events and extra available capital. This marks an important step that we believe will enhance our portfolio and create additional shareholder value.”

  www.arrowheadresearch.com.