Hydrogel superglue is 90 percent water
(Nanowerk News) Nature has developed innovative ways to solve a sticky challenge: Mussels and barnacles stubbornly glue themselves to cliff faces, ship hulls, and even the skin of whales. Likewise, tendons and cartilage stick to bone with incredible robustness, giving animals flexibility and agility.
The natural adhesive in all these cases is hydrogel — a sticky mix of water and gummy material that creates a tough and durable bond.
Now engineers at MIT have developed a method to make synthetic, sticky hydrogel that is more than 90 percent water. The hydrogel, which is a transparent, rubber-like material, can adhere to surfaces such as glass, silicon, ceramics, aluminum, and titanium with a toughness comparable to the bond between tendon and cartilage on bone.
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In experiments to demonstrate its robustness, the researchers applied a small square of their hydrogel between two plates of glass, from which they then suspended a 55-pound weight. They also glued the hydrogel to a silicon wafer, which they then smashed with a hammer. While the silicon shattered, its pieces remained stuck in place.
Such durability makes the hydrogel an ideal candidate for protective coatings on underwater surfaces such as boats and submarines. As the hydrogel is biocompatible, it may also be suitable for a range of health-related applications, such as biomedical coatings for catheters and sensors implanted in the body.
“You can imagine new applications with this very robust, adhesive, yet soft material,” says Xuanhe Zhao, the Robert N. Noyce Career Development Associate Professor in MIT’s Department of Mechanical Engineering. For example, Zhao’s group is currently exploring uses for the hydrogel in soft robotics, where the material may serve as synthetic tendon and cartilage, or in flexible joints.
“It’s a pretty tough and adhesive gel that’s mostly water,” Hyunwoo Yuk, a graduate student in mechanical engineering and the lead author of a paper on the work, says. “Basically, it’s tough, bonding water.”
Zhao and his students publish their results today in the journal Nature Materials ("Tough bonding of hydrogels to diverse non-porous surfaces").
Read more: Hydrogel superglue is 90 percent water
http://www.nanowerk.com/nanotechnology-news/newsid=41807.php
(Nanowerk News) Nature has developed innovative ways to solve a sticky challenge: Mussels and barnacles stubbornly glue themselves to cliff faces, ship hulls, and even the skin of whales. Likewise, tendons and cartilage stick to bone with incredible robustness, giving animals flexibility and agility.
The natural adhesive in all these cases is hydrogel — a sticky mix of water and gummy material that creates a tough and durable bond.
Now engineers at MIT have developed a method to make synthetic, sticky hydrogel that is more than 90 percent water. The hydrogel, which is a transparent, rubber-like material, can adhere to surfaces such as glass, silicon, ceramics, aluminum, and titanium with a toughness comparable to the bond between tendon and cartilage on bone.
@nanotech1
In experiments to demonstrate its robustness, the researchers applied a small square of their hydrogel between two plates of glass, from which they then suspended a 55-pound weight. They also glued the hydrogel to a silicon wafer, which they then smashed with a hammer. While the silicon shattered, its pieces remained stuck in place.
Such durability makes the hydrogel an ideal candidate for protective coatings on underwater surfaces such as boats and submarines. As the hydrogel is biocompatible, it may also be suitable for a range of health-related applications, such as biomedical coatings for catheters and sensors implanted in the body.
“You can imagine new applications with this very robust, adhesive, yet soft material,” says Xuanhe Zhao, the Robert N. Noyce Career Development Associate Professor in MIT’s Department of Mechanical Engineering. For example, Zhao’s group is currently exploring uses for the hydrogel in soft robotics, where the material may serve as synthetic tendon and cartilage, or in flexible joints.
“It’s a pretty tough and adhesive gel that’s mostly water,” Hyunwoo Yuk, a graduate student in mechanical engineering and the lead author of a paper on the work, says. “Basically, it’s tough, bonding water.”
Zhao and his students publish their results today in the journal Nature Materials ("Tough bonding of hydrogels to diverse non-porous surfaces").
Read more: Hydrogel superglue is 90 percent water
http://www.nanowerk.com/nanotechnology-news/newsid=41807.php
Nanowerk
Hydrogel superglue is 90 percent water
Engineers have developed a method to make synthetic, sticky hydrogel that is more than 90 percent water. The hydrogel, which is a transparent, rubber-like material, can adhere to surfaces such as glass, silicon, ceramics, aluminum, and titanium with a toughness…
Nanobodies from camels enable the study of organ growth
(Nanowerk News) Researchers at the Biozentrum of the University of Basel have developed a new technique using nanobodies. Employing the so-called “Morphotrap”, the distribution of the morphogen Dpp, which plays an important role in wing development, could be selectively manipulated and analyzed for the first time in the fruit fly. In the future, this tool may be applied for many further investigations of organ growth. The results of the study have been published in the current issue of Nature ("Dpp spreading is required for medial but not for lateral wing disc growth").
@nanotech1
The two basic processes that control organ development are the regulation of growth and of the spatial pattern. The research group of Prof. Markus Affolter at the Biozentrum, University of Basel, has now developed a method named “Morphotrap” to study wing development in the fruit fly.
Their results demonstrate that the signaling molecule Dpp, a so-called morphogen, influences growth in the center of the wing imaginal disc but not in the peripheral regions. It is the first time that an anti-GFP nanobody has been successfully employed in such an investigation. This tool also holds promise for future studies on organ development.
The new method “Morphotrap”: Nanobodies to study growth
Nanobodies are small antibody fragments derived from camels. They enable the research team of Markus Affolter to manipulate molecules in the living organism. The so-called “Morphotrap” method employs anti-GFP nanobodies. Using these Nanobodies, the functions of GFP-tagged proteins in living organisms can be studied faster and more effectively than by conventional methods.
“These anti-GFP nanobodies inhibit the dispersal of the morphogen Dpp at different locations in the wing. Therefore they allow us to identify the influence of Dpp spreading on wing growth,” explains Stefan Harmansa, the first author of the study.
Morphogen Dpp regulates growth in the middle of the imaginal disc
To determine the influence of the morphogen Decapentaplegic (Dpp) in more detail, the Affolter group examined the wing disc of the fruit fly, called the imaginal disc. This is the precursor tissue of the wing of the adult fly and serves as a model for studies on organ development.
“Our findings demonstrate that the morphogen Dpp only affects growth in the center of the imaginal disc. Growth continues in the periphery even when we fully block Dpp dispersal into this regions,” explains Harmansa. “Now, by employing anti GFP nanobodies, we have been able to show to which extent the morphogen Dpp determines the wing size and consequently we could disprove one of the two predominant theories in this field,” says Harmansa.
The fact that anti GFP-nanobodies can successfully be applied for research in complex living organism is a great achievement. Affolter also plans to apply this technique in future research: “In a next step, we will investigate at what time in development Dpp acts to control central growth. The correlation between the spatial and temporal influence of Dpp will provide new insights into organ growth and may uncover possible causes of organ malformation,” says Affolter.
Read more: Nanobodies from camels enable the study of organ growth
(Nanowerk News) Researchers at the Biozentrum of the University of Basel have developed a new technique using nanobodies. Employing the so-called “Morphotrap”, the distribution of the morphogen Dpp, which plays an important role in wing development, could be selectively manipulated and analyzed for the first time in the fruit fly. In the future, this tool may be applied for many further investigations of organ growth. The results of the study have been published in the current issue of Nature ("Dpp spreading is required for medial but not for lateral wing disc growth").
@nanotech1
The two basic processes that control organ development are the regulation of growth and of the spatial pattern. The research group of Prof. Markus Affolter at the Biozentrum, University of Basel, has now developed a method named “Morphotrap” to study wing development in the fruit fly.
Their results demonstrate that the signaling molecule Dpp, a so-called morphogen, influences growth in the center of the wing imaginal disc but not in the peripheral regions. It is the first time that an anti-GFP nanobody has been successfully employed in such an investigation. This tool also holds promise for future studies on organ development.
The new method “Morphotrap”: Nanobodies to study growth
Nanobodies are small antibody fragments derived from camels. They enable the research team of Markus Affolter to manipulate molecules in the living organism. The so-called “Morphotrap” method employs anti-GFP nanobodies. Using these Nanobodies, the functions of GFP-tagged proteins in living organisms can be studied faster and more effectively than by conventional methods.
“These anti-GFP nanobodies inhibit the dispersal of the morphogen Dpp at different locations in the wing. Therefore they allow us to identify the influence of Dpp spreading on wing growth,” explains Stefan Harmansa, the first author of the study.
Morphogen Dpp regulates growth in the middle of the imaginal disc
To determine the influence of the morphogen Decapentaplegic (Dpp) in more detail, the Affolter group examined the wing disc of the fruit fly, called the imaginal disc. This is the precursor tissue of the wing of the adult fly and serves as a model for studies on organ development.
“Our findings demonstrate that the morphogen Dpp only affects growth in the center of the imaginal disc. Growth continues in the periphery even when we fully block Dpp dispersal into this regions,” explains Harmansa. “Now, by employing anti GFP nanobodies, we have been able to show to which extent the morphogen Dpp determines the wing size and consequently we could disprove one of the two predominant theories in this field,” says Harmansa.
The fact that anti GFP-nanobodies can successfully be applied for research in complex living organism is a great achievement. Affolter also plans to apply this technique in future research: “In a next step, we will investigate at what time in development Dpp acts to control central growth. The correlation between the spatial and temporal influence of Dpp will provide new insights into organ growth and may uncover possible causes of organ malformation,” says Affolter.
Read more: Nanobodies from camels enable the study of organ growth
Nanoparticle delivery maximizes drug defense against bioterrorism agent
(Nanowerk News) Scientists from the California NanoSystems Institute at UCLA have developed a nanoparticle delivery system for the antibiotic moxifloxacin that vastly improves the drug’s effectiveness against pneumonic tularemia, a type of pneumonia caused by inhalation of the bacterium Francisella tularensis.
The study, which appears in the journal ACS Nano ("Mesoporous Silica Nanoparticles with pH-Sensitive Nanovalves for Delivery of Moxifloxacin Provide Improved Treatment of Lethal Pneumonic Tularemia"), shows how the nanoparticle system targets the precise cells infected by the bacteria and maximizes the amount of drug delivered to those cells.
Jeffrey Zink, distinguished professor of chemistry and biochemistry and a senior author on the study, developed the mesoporous silica nanoparticles used for drug delivery. Zink and his research team conducted an exhaustive process to find the best particle for the job.
@nanotech1
“The nanoparticles are full of deep empty pores,” Zink said. “We place the particles in drug solution overnight, filling the pores with drug molecules. We then block the pore openings on the nanoparticle’s surface with molecules called nanovalves, sealing the drug inside the nanoparticle.”
When the drug-bearing nanoparticles are injected into the infected animal, in this case a mouse, the drug stays in the nanoparticles until they reach their target: white blood cells called macrophages. Macrophages ingest nanoparticles into compartments that have an acidic environment. The nanovalves, which are designed to open in response to the more acidic surroundings, then release the drug.
“We tested several different particles and nanovalves until we found the ones that would carry the maximum amount of drug and release it at just the right pH value,” Zink said.
The F. tularensis bacterium is highly infectious and has been designated a top-tier bioterrorism agent by the Centers for Disease control, meaning that it is considered to pose a high risk to national security and public health.
“F. tularensis survives and multiplies within macrophages, especially those in the liver, spleen and lung,” said Marcus Horwitz, a distinguished professor of medicine and microbiology, immunology and molecular genetics and the study’s other senior author. “Macrophages readily devour mesoporous silica nanoparticles, making these particles ideal for treating these types of infections.”
Moxifloxacin is a powerful treatment for tularemia, but it has side effects when administered as a free drug in the bloodstream. The UCLA researchers worked to maximize the efficacy of the treatment while reducing side effects.
“When you give a drug freely in the blood, only 1 or 2 percent of it gets to where you want it to go,” Horwitz said. “With this system, the drug is contained inside the nanoparticles until they are inside macrophages, delivering a much larger amount of the drug directly to the site of infection.”
Horwitz added that freely flowing drugs are metabolized and excreted from the moment they are administered, whereas nanoparticles protect drug molecules from metabolism and excretion until after their release in the target cells, making nanotherapeutics potentially very potent.
The study compared the efficacy of freely injected moxifloxacin with that delivered by the controlled-release nanoparticles. In mice given a highly lethal dose of Francisella tularensis, the nanoparticle-delivered moxifloxacin caused few side effects and was more effective at reducing the number of bacteria in the lungs than a dose of freely injected moxifloxacin two to four times greater.
The nanoparticle delivery system has the potential to maximize antibiotic effectiveness and reduce side effects in other infectious diseases including tuberculosis, Q fever and Legionnaires’ disease.
Read more: Nanoparticle delivery maximizes drug defense against bioterrorism agent
http://www.nanowerk.com/nanotechnology-news/newsid=41782.php
(Nanowerk News) Scientists from the California NanoSystems Institute at UCLA have developed a nanoparticle delivery system for the antibiotic moxifloxacin that vastly improves the drug’s effectiveness against pneumonic tularemia, a type of pneumonia caused by inhalation of the bacterium Francisella tularensis.
The study, which appears in the journal ACS Nano ("Mesoporous Silica Nanoparticles with pH-Sensitive Nanovalves for Delivery of Moxifloxacin Provide Improved Treatment of Lethal Pneumonic Tularemia"), shows how the nanoparticle system targets the precise cells infected by the bacteria and maximizes the amount of drug delivered to those cells.
Jeffrey Zink, distinguished professor of chemistry and biochemistry and a senior author on the study, developed the mesoporous silica nanoparticles used for drug delivery. Zink and his research team conducted an exhaustive process to find the best particle for the job.
@nanotech1
“The nanoparticles are full of deep empty pores,” Zink said. “We place the particles in drug solution overnight, filling the pores with drug molecules. We then block the pore openings on the nanoparticle’s surface with molecules called nanovalves, sealing the drug inside the nanoparticle.”
When the drug-bearing nanoparticles are injected into the infected animal, in this case a mouse, the drug stays in the nanoparticles until they reach their target: white blood cells called macrophages. Macrophages ingest nanoparticles into compartments that have an acidic environment. The nanovalves, which are designed to open in response to the more acidic surroundings, then release the drug.
“We tested several different particles and nanovalves until we found the ones that would carry the maximum amount of drug and release it at just the right pH value,” Zink said.
The F. tularensis bacterium is highly infectious and has been designated a top-tier bioterrorism agent by the Centers for Disease control, meaning that it is considered to pose a high risk to national security and public health.
“F. tularensis survives and multiplies within macrophages, especially those in the liver, spleen and lung,” said Marcus Horwitz, a distinguished professor of medicine and microbiology, immunology and molecular genetics and the study’s other senior author. “Macrophages readily devour mesoporous silica nanoparticles, making these particles ideal for treating these types of infections.”
Moxifloxacin is a powerful treatment for tularemia, but it has side effects when administered as a free drug in the bloodstream. The UCLA researchers worked to maximize the efficacy of the treatment while reducing side effects.
“When you give a drug freely in the blood, only 1 or 2 percent of it gets to where you want it to go,” Horwitz said. “With this system, the drug is contained inside the nanoparticles until they are inside macrophages, delivering a much larger amount of the drug directly to the site of infection.”
Horwitz added that freely flowing drugs are metabolized and excreted from the moment they are administered, whereas nanoparticles protect drug molecules from metabolism and excretion until after their release in the target cells, making nanotherapeutics potentially very potent.
The study compared the efficacy of freely injected moxifloxacin with that delivered by the controlled-release nanoparticles. In mice given a highly lethal dose of Francisella tularensis, the nanoparticle-delivered moxifloxacin caused few side effects and was more effective at reducing the number of bacteria in the lungs than a dose of freely injected moxifloxacin two to four times greater.
The nanoparticle delivery system has the potential to maximize antibiotic effectiveness and reduce side effects in other infectious diseases including tuberculosis, Q fever and Legionnaires’ disease.
Read more: Nanoparticle delivery maximizes drug defense against bioterrorism agent
http://www.nanowerk.com/nanotechnology-news/newsid=41782.php
Nanowerk
Nanoparticle delivery maximizes drug defense against bioterrorism agent
Scientists have developed a nanoparticle delivery system for the antibiotic moxifloxacin that vastly improves the drug's effectiveness against pneumonic tularemia, a type of pneumonia caused by inhalation of the bacterium Francisella tularensis.
The nano-grip This is an SEM image (color enhanced by Photoshop) of high aspect ratio 250nm thick epoxy bristles that have self assembled and trapped a 2.5 micron diameter PS sphere.
Read more: Nano Teddybear, Garden of Eden and other spectacular nanotechnology images
Read more: Nano Teddybear, Garden of Eden and other spectacular nanotechnology images
Modern Stonehenge Colorized SEM image of silicon nanopillar formation created by Gallium implantation and DRIE-etching
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@nanotech1
ترکیب سلژل و اسیدچرب برای ساخت خازن
@nanotech1
محققان با استفاده از لایه نازکی از جنس اسید چرب و ترکیب آن با هیدروژل، موفق به ساخت خازنی با دانسیته جریان بالا شدند. این خازن میتواند در خودروهای برقی استفاده شود.
محققان با استفاده از ترکیب سلژل با ترکیبات تکلایه خودآرا از جنس اسید چرب موفق به ساخت ماده دیالکتریکی جدیدی برای خازنها شدند. با استفاده از این ماده جدید هم امکان تولید دانسیته انرژی بالایی وجود دارد و هم دانسیته توان بالایی ایجاد میشود.
در صورتی که ساخت این ماده تجاریسازی شود آنگاه میتوان ظرفیت خازنها را تا حدی بالا برد که بتوان از آن در خودروهای برقی استفاده کرد. خازنها مکمل باتریها هستند و مزیت آنها، امکان ایجاد سریع جریان بالا است.
این ماده جدید از جنس لایه نازک سلژل سیلیکا بوده که حاوی گروههای قطبی است که به اتمهای سیلیکون لینک شدهاست. همچنین تک لایه خودآرا از جنس اسید استیلفسفونیک در این ساختار استفاده شدهاست که نقش ماده عایق را ایفا میکند.
ژوزف پری از محققان موسسه فناوری جرجیا میگوید: «سلژل با گروههای آلی بسیار شناخته شده هستند، همچنین اسیدهای چربی نظیر اسید فسفونیک نیز برای محققان آشنا است. اما این اولین باری است که این دو ماده با هم ترکیب شده و در دستگاه ذخیره انرژی با دانسیته بالا استفاده میشود.»
نتایج این پروژه در قالب مقالهای با عنوان Bilayer Structure with Ultra-high Energy/Power Density Using Hybrid Sol-Gel Dielectric and Charge Blocking Monolayer در نشریه Advanced Energy Materials منتشر شدهاست.
نیاز به مواد با کارایی بالا برای ذخیره انرژی الکتریکی در حال رشد است. مواد دی الکتریکی امکان شارژ و تخلیه سریع را فراهم میکنند. اما این که بتوان مادهای یافت که هم نفوذپذیری بالایی داشته باشد، مستحکم باشد و امکان ایجاد دانسیته انرژی بالایی را داشته باشد بسیار دشوار است.
این گروه تحقیقاتی به دنبال ساخت مادهای با این شرایط برای استفاده در خازنها هستند. این هیبرید سلژل دارای پتانسیل بالایی برای به کارگیری در ذخیره انرژی است؛ به همین دلیل، محققان تصمیم گرفتند تا از آن در ساخت خازن استفاده کنند.
این گروه با استفاده از فیلم آلومینیومی حاوی پوششی از این سلژل اقدام به ساخت خازنی کردند که دانسیته جریان بسیار بالایی ایجاد کرده و کاملا انعطافپذیر است. این ابرخازن نشت جریان داشت که برای حل آن محققان از تک لایههای خودآرا از جنس اسید چرب استفاده کردند؛ لایهای که ضخامت یک نانومتری دارد. از این لایه بهعنوان عایق در این پروژه استفاده شد. http://news.nano.ir/51566/1
@nanotech1
محققان با استفاده از لایه نازکی از جنس اسید چرب و ترکیب آن با هیدروژل، موفق به ساخت خازنی با دانسیته جریان بالا شدند. این خازن میتواند در خودروهای برقی استفاده شود.
محققان با استفاده از ترکیب سلژل با ترکیبات تکلایه خودآرا از جنس اسید چرب موفق به ساخت ماده دیالکتریکی جدیدی برای خازنها شدند. با استفاده از این ماده جدید هم امکان تولید دانسیته انرژی بالایی وجود دارد و هم دانسیته توان بالایی ایجاد میشود.
در صورتی که ساخت این ماده تجاریسازی شود آنگاه میتوان ظرفیت خازنها را تا حدی بالا برد که بتوان از آن در خودروهای برقی استفاده کرد. خازنها مکمل باتریها هستند و مزیت آنها، امکان ایجاد سریع جریان بالا است.
این ماده جدید از جنس لایه نازک سلژل سیلیکا بوده که حاوی گروههای قطبی است که به اتمهای سیلیکون لینک شدهاست. همچنین تک لایه خودآرا از جنس اسید استیلفسفونیک در این ساختار استفاده شدهاست که نقش ماده عایق را ایفا میکند.
ژوزف پری از محققان موسسه فناوری جرجیا میگوید: «سلژل با گروههای آلی بسیار شناخته شده هستند، همچنین اسیدهای چربی نظیر اسید فسفونیک نیز برای محققان آشنا است. اما این اولین باری است که این دو ماده با هم ترکیب شده و در دستگاه ذخیره انرژی با دانسیته بالا استفاده میشود.»
نتایج این پروژه در قالب مقالهای با عنوان Bilayer Structure with Ultra-high Energy/Power Density Using Hybrid Sol-Gel Dielectric and Charge Blocking Monolayer در نشریه Advanced Energy Materials منتشر شدهاست.
نیاز به مواد با کارایی بالا برای ذخیره انرژی الکتریکی در حال رشد است. مواد دی الکتریکی امکان شارژ و تخلیه سریع را فراهم میکنند. اما این که بتوان مادهای یافت که هم نفوذپذیری بالایی داشته باشد، مستحکم باشد و امکان ایجاد دانسیته انرژی بالایی را داشته باشد بسیار دشوار است.
این گروه تحقیقاتی به دنبال ساخت مادهای با این شرایط برای استفاده در خازنها هستند. این هیبرید سلژل دارای پتانسیل بالایی برای به کارگیری در ذخیره انرژی است؛ به همین دلیل، محققان تصمیم گرفتند تا از آن در ساخت خازن استفاده کنند.
این گروه با استفاده از فیلم آلومینیومی حاوی پوششی از این سلژل اقدام به ساخت خازنی کردند که دانسیته جریان بسیار بالایی ایجاد کرده و کاملا انعطافپذیر است. این ابرخازن نشت جریان داشت که برای حل آن محققان از تک لایههای خودآرا از جنس اسید چرب استفاده کردند؛ لایهای که ضخامت یک نانومتری دارد. از این لایه بهعنوان عایق در این پروژه استفاده شد. http://news.nano.ir/51566/1
news.nano.ir
ستاد ويژه توسعه فناوري نانو | اخبار | ترکیب سلژل و اسیدچرب برای ساخت خازن
محققان با استفاده از لایه نازکی از جنس اسید چرب و ترکیب آن با هیدروژل، موفق به ساخت خازنی با دانسیته جریان بالا شدند. این خازن میتواند در خودروهای برقی استفاده شود.
Scanning near-field optical microscopy (SNOM) uses nanoscale metal tips to scan a surface. Here, a standard tip has been modified and sharpened to increase its precision. The tip in the middle of this structure measures a few tens of nanometers.
Read more: Blow-up: The startling landscapes of nanotechnology
Read more: Blow-up: The startling landscapes of nanotechnology
Developing new instruments to be able to "see" at the nanoscale is a research field in itself. Shown here is the tip of an atomic force microscope (AFM), one of the foremost tools for imaging, measuring and manipulating matter at the nanoscale. Here, a platinum electrode measuring one hundredth of a nanometer has been deposited on the tip of this pyramid shaped AFM tip via focused ion beam (FIB) deposition.
Read more: Blow-up: The startling landscapes of nanotechnology
Read more: Blow-up: The startling landscapes of nanotechnology