Under a microscope they look like tiny pie charts or colorful candy canes: A team led by Joerg Lahann at the University of Michigan (USA) has been able to produce micrometer-wide discs and elongated rods precisely built out of multicolored compartments.
As reported in the journal Angewandte Chemie, these scientists have developed a simple, cost-effective, reliable, and scalable method for the production of microcylinders with multiple compartments. The inner structure, aspect ratio, and surface chemistry can be tuned by means of the new production method which is based on electrodynamic co-spinning and microcutting processes.
Bicolor cylinders were made by pumping two differently colored biodegradable polymer solutions through two side-by-side jets. An electrical field stretches the exiting drops, resulting in a bicompartmental fiber that is “spun” into a bundle of parallel individual fibers. The researchers embed the 1 cm long fiber bundles in a gel, which they then freeze. Using a microtome, they slice off thin sections. Upon dissolution of the gel in water and treatment with ultrasound, the bundles can be separated into individual cylinders of uniform size. The length of the cylinders depends on the thickness of the microtome sections, which allows for the production of everything from flat discs to long rods.
If more than two jets are used, it is possible to make fibers out of three, four, or more different components. Depending on the arrangement of the jets, different patterns can be generated. For example, it is possible to fabricate cylindrical particles that look like a three-section or four-section pie chart. If the jets are positioned next to each other, the result is a striped structure. The individual segments are always identical in size and are clearly delineated.
Instead of dyeing the components, it is also possible to attach various (bio-)reagents to the segments of the cylinders if specific “anchor sites” are built into the polymer. Special shapes can also be produced when one or more segments are made of a polymer that can be selectively dissolved. For example, one fourth of a four-component cylinder can be removed to make a rod with a groove.
The new method can be used to produce particles made of precisely designed compartments with mutually independent physical and chemical properties. Possible areas of application include drug transport, tissue culture, and bundled biotests, as well as “intelligent displays” and reactive materials.
Author: Joerg Lahann, University of Michigan, Ann Arbor (USA), http://www.engin.umich.edu/dept/cheme/people/lahann.html
Title: Multicompartmental Microcylinders
Angewandte Chemie International Edition, doi: 10.1002/anie.200806241
Joerg Lahann | Angewandte Chemie
At last, butterflies get a bigger, better evolutionary tree
16.02.2018 | Florida Museum of Natural History
New treatment strategies for chronic kidney disease from the animal kingdom
16.02.2018 | Veterinärmedizinische Universität Wien
Breakthrough provides a new concept of the design of molecular motors, sensors and electricity generators at nanoscale
Researchers from the Institute of Organic Chemistry and Biochemistry of the CAS (IOCB Prague), Institute of Physics of the CAS (IP CAS) and Palacký University...
For photographers and scientists, lenses are lifesavers. They reflect and refract light, making possible the imaging systems that drive discovery through the microscope and preserve history through cameras.
But today's glass-based lenses are bulky and resist miniaturization. Next-generation technologies, such as ultrathin cameras or tiny microscopes, require...
Scientists from the University of Zurich have succeeded for the first time in tracking individual stem cells and their neuronal progeny over months within the intact adult brain. This study sheds light on how new neurons are produced throughout life.
The generation of new nerve cells was once thought to taper off at the end of embryonic development. However, recent research has shown that the adult brain...
Theoretical physicists propose to use negative interference to control heat flow in quantum devices. Study published in Physical Review Letters
Quantum computer parts are sensitive and need to be cooled to very low temperatures. Their tiny size makes them particularly susceptible to a temperature...
Let’s say the armrest is broken in your vintage car. As things stand, you would need a lot of luck and persistence to find the right spare part. But in the world of Industrie 4.0 and production with batch sizes of one, you can simply scan the armrest and print it out. This is made possible by the first ever 3D scanner capable of working autonomously and in real time. The autonomous scanning system will be on display at the Hannover Messe Preview on February 6 and at the Hannover Messe proper from April 23 to 27, 2018 (Hall 6, Booth A30).
Part of the charm of vintage cars is that they stopped making them long ago, so it is special when you do see one out on the roads. If something breaks or...
15.02.2018 | Event News
13.02.2018 | Event News
12.02.2018 | Event News
16.02.2018 | Information Technology
16.02.2018 | Health and Medicine
16.02.2018 | Physics and Astronomy