Proteins are an interesting class of drugs because they demonstrate high biological activity and are highly specific in their effects. It has become possible to produce more and more proteins with tailored pharmacological properties; however transport and controlled release of the protein drugs in the body have remained a challenge.
In the journal Angewandte Chemie, Helmuth Möhwald of the Max Planck Institute of Colloids and Interfaces in Golm/Potsdam (Germany) and Dmitry V. Volodkin and Regine von Klitzing of the TU Berlin (Germany) have now introduced an alternative to the usual transport agents, such as liposomes: by using a simple, inexpensive, gentle process, they were able to produce pure protein microspheres of uniform size.
Loading nano- and microscale transport systems with proteins is the most common strategy used to bring drugs to their target area and achieve a longer period of activity. The challenge is to produce particles with a precisely defined quantity of protein, size, morphology, composition, and density. These characteristics are critical for the attainment of high bioavailability and a defined rate of release at the desired location. Unfortunately, they are difficult to control when using conventional methods for the production of protein particles, such as crystallization, spray drying, or incorporation in liposomes or polymer matrices. Another disadvantage is that these processes generally require organic solvents, high temperatures, or other conditions that can compromise the stability of the proteins.
The researchers were looking for a method that would deliver uniform protein particles without destructive additives and under mild conditions. The team has now developed such a method, which is also very simple and inexpensive, and successfully tested it on insulin, a classic therapeutic protein. The secret to their success lies in porous calcium carbonate microspheres of defined size, and a change of pH value. In a slightly alkaline aqueous environment (high pH value), the protein insulin is soluble. When the calcium carbonate spheres are added to such a protein solution, their pores are filled with the insulin solution. When the solution is then neutralized with acid, the insulin becomes insoluble and precipitates out in the pores. If the solution is acidified further, until the calcium carbonate spheres slowly begin to dissolve in the slightly acidic solution. The insulin remains behind as a loose matrix, which shrinks down into compact micrometer-scale spheres. This results in protein particles of uniform size and high protein density.
Author: Dmitry V. Volodkin, Technische Universität Berlin (Germany), http://www.chemie.tu-berlin.de/klitzing/menue/ueber_uns/arbeitsgruppe/volodkin/
Title: Pure Protein Microspheres by Calcium Carbonate Templating
Angewandte Chemie International Edition, Permalink to the article: http://dx.doi.org/10.1002/anie.201005089
Dmitry V. Volodkin | Angewandte Chemie
Rainbow colors reveal cell history: Uncovering β-cell heterogeneity
22.09.2017 | DFG-Forschungszentrum für Regenerative Therapien TU Dresden
The pyrenoid is a carbon-fixing liquid droplet
22.09.2017 | Max-Planck-Institut für Biochemie
Plants and algae use the enzyme Rubisco to fix carbon dioxide, removing it from the atmosphere and converting it into biomass. Algae have figured out a way to increase the efficiency of carbon fixation. They gather most of their Rubisco into a ball-shaped microcompartment called the pyrenoid, which they flood with a high local concentration of carbon dioxide. A team of scientists at Princeton University, the Carnegie Institution for Science, Stanford University and the Max Plank Institute of Biochemistry have unravelled the mysteries of how the pyrenoid is assembled. These insights can help to engineer crops that remove more carbon dioxide from the atmosphere while producing more food.
A warming planet
Our brains house extremely complex neuronal circuits, whose detailed structures are still largely unknown. This is especially true for the so-called cerebral cortex of mammals, where among other things vision, thoughts or spatial orientation are being computed. Here the rules by which nerve cells are connected to each other are only partly understood. A team of scientists around Moritz Helmstaedter at the Frankfiurt Max Planck Institute for Brain Research and Helene Schmidt (Humboldt University in Berlin) have now discovered a surprisingly precise nerve cell connectivity pattern in the part of the cerebral cortex that is responsible for orienting the individual animal or human in space.
The researchers report online in Nature (Schmidt et al., 2017. Axonal synapse sorting in medial entorhinal cortex, DOI: 10.1038/nature24005) that synapses in...
Whispering gallery mode (WGM) resonators are used to make tiny micro-lasers, sensors, switches, routers and other devices. These tiny structures rely on a...
Using ultrafast flashes of laser and x-ray radiation, scientists at the Max Planck Institute of Quantum Optics (Garching, Germany) took snapshots of the briefest electron motion inside a solid material to date. The electron motion lasted only 750 billionths of the billionth of a second before it fainted, setting a new record of human capability to capture ultrafast processes inside solids!
When x-rays shine onto solid materials or large molecules, an electron is pushed away from its original place near the nucleus of the atom, leaving a hole...
For the first time, physicists have successfully imaged spiral magnetic ordering in a multiferroic material. These materials are considered highly promising candidates for future data storage media. The researchers were able to prove their findings using unique quantum sensors that were developed at Basel University and that can analyze electromagnetic fields on the nanometer scale. The results – obtained by scientists from the University of Basel’s Department of Physics, the Swiss Nanoscience Institute, the University of Montpellier and several laboratories from University Paris-Saclay – were recently published in the journal Nature.
Multiferroics are materials that simultaneously react to electric and magnetic fields. These two properties are rarely found together, and their combined...
19.09.2017 | Event News
12.09.2017 | Event News
06.09.2017 | Event News
22.09.2017 | Life Sciences
22.09.2017 | Medical Engineering
22.09.2017 | Physics and Astronomy