Our breakfast egg is a peculiarity of nature: a single cell protected by a thin mineral layer. Apart from a number of tiny radiolaria and diatoms, individual cells normally do not have a hard shell.
Korean researchers have now developed a strategy for equipping individual cells of baker’s yeast, Saccharomyces cerevisiae, with a synthetic shell made of silicon dioxide. As the team led by Insung S. Choi reports in the journal Angewandte Chemie, the lifespan of these coated yeast cells is tripled, whilst their division is suppressed. The shell also protects the cells from unfavorable external conditions.
Whereas other research efforts previously succeeded in coating yeast cells with a phosphate mineral layer, individual cells have not previously been encapsulated in silicon dioxide. Inspired by the natural shell formation of diatoms, the researchers developed a biomimetic process to coat individual cells under mild physiological conditions. The surfaces of diatoms are covered with special long-chain molecules that contain many positively charged groups of atoms and initiate biomineralization.
The researchers imitated this process by equipping the cell membranes of the yeast cells with synthetic polymers, always alternating layers with many positive charges and layers with many negative charges -- a total of 21 layers. When the yeast cells that have been treated in this way are placed in a solution containing negatively charged silicic acid compounds, these dock onto the outermost positively charged layer of the yeast shell. There they mineralize to silicon dioxide and completely encapsulate the yeast cells.
Genetically modified yeasts are used to produce important pharmaceutical agents. In molecular biological research, easily cultivated yeasts are often used for fundamental investigations of cellular processes and for the diagnosis of human diseases. The protection and improved shelf life possible because of the shell could enable new avenues of research. In addition, the shell could act as a scaffold for the introduction of modifications to the chemical and biological properties.
Author: Insung S. Choi, KAIST, Daejeon (Republic of Korea), http://cisgroup.kaist.ac.kr/
Title: Biomimetic Encapsulation of Individual Cells with Silica
Angewandte Chemie International Edition, doi: 10.1002/anie.200903010
Water forms 'spine of hydration' around DNA, group finds
26.05.2017 | Cornell University
How herpesviruses win the footrace against the immune system
26.05.2017 | Helmholtz-Zentrum für Infektionsforschung
Staphylococcus aureus is a feared pathogen (MRSA, multi-resistant S. aureus) due to frequent resistances against many antibiotics, especially in hospital infections. Researchers at the Paul-Ehrlich-Institut have identified immunological processes that prevent a successful immune response directed against the pathogenic agent. The delivery of bacterial proteins with RNA adjuvant or messenger RNA (mRNA) into immune cells allows the re-direction of the immune response towards an active defense against S. aureus. This could be of significant importance for the development of an effective vaccine. PLOS Pathogens has published these research results online on 25 May 2017.
Staphylococcus aureus (S. aureus) is a bacterium that colonizes by far more than half of the skin and the mucosa of adults, usually without causing infections....
Physicists from the University of Würzburg are capable of generating identical looking single light particles at the push of a button. Two new studies now demonstrate the potential this method holds.
The quantum computer has fuelled the imagination of scientists for decades: It is based on fundamentally different phenomena than a conventional computer....
An international team of physicists has monitored the scattering behaviour of electrons in a non-conducting material in real-time. Their insights could be beneficial for radiotherapy.
We can refer to electrons in non-conducting materials as ‘sluggish’. Typically, they remain fixed in a location, deep inside an atomic composite. It is hence...
Two-dimensional magnetic structures are regarded as a promising material for new types of data storage, since the magnetic properties of individual molecular building blocks can be investigated and modified. For the first time, researchers have now produced a wafer-thin ferrimagnet, in which molecules with different magnetic centers arrange themselves on a gold surface to form a checkerboard pattern. Scientists at the Swiss Nanoscience Institute at the University of Basel and the Paul Scherrer Institute published their findings in the journal Nature Communications.
Ferrimagnets are composed of two centers which are magnetized at different strengths and point in opposing directions. Two-dimensional, quasi-flat ferrimagnets...
An Australian-Chinese research team has created the world's thinnest hologram, paving the way towards the integration of 3D holography into everyday...
24.05.2017 | Event News
23.05.2017 | Event News
22.05.2017 | Event News
26.05.2017 | Life Sciences
26.05.2017 | Life Sciences
26.05.2017 | Physics and Astronomy