Phospholipids are a class of lipids whose molecule has a hydrophilic "head" containing a phosphate group and two hydrophobic "tails" derived from fatty acids, joined by an alcohol residue. Marine phospholipids typically have omega-3 fatty acids EPA and DHA integrated as part of the phospholipid molecule. The phosphate group can be modified with simple organic molecules such as choline, ethanolamine or serine.
The lipid bilayer is a thin polar membrane made of two layers of lipid molecules. These membranes are flat sheets that form a continuous barrier around all cells. The cell membranes of almost all organisms and many viruses are made of a lipid bilayer, as are the nuclear membrane surrounding the cell nucleus, and membranes of the membrane-bound organelles in the cell. The lipid bilayer is the barrier that keeps ions, proteins and other molecules where they are needed and prevents them from diffusing into areas where they should not be. Lipid bilayers are ideally suited to this role, even though they are only a few nanometers in width, because they are impermeable to most water-soluble (hydrophilic) molecules. Bilayers are particularly impermeable to ions, which allows cells to regulate salt concentrations and pH by transporting ions across their membranes using proteins called ion pumps.
Membrane proteins are common proteins that are part of, or interact with, biological membranes. Membrane proteins fall into several broad categories depending on their location. Integral membrane proteins are a permanent part of a cell membrane and can either penetrate the membrane (transmembrane) or associate with one or the other side of a membrane. Peripheral membrane proteins are transiently associated with the cell membrane.
Semipermeable membrane is a type of biological or synthetic, polymeric membrane that allows certain molecules or ions to pass through it by osmosis. The rate of passage depends on the pressure, concentration, and temperature of the molecules or solutes on either side, as well as the permeability of the membrane to each solute. Depending on the membrane and the solute, permeability may depend on solute size, solubility, properties, or chemistry. How the membrane is constructed to be selective in its permeability will determine the rate and the permeability. Many natural and synthetic materials which are rather thick are also semipermeable. One example of this is the thin film on the inside of an egg.
A liposome is a small artificial vesicle, spherical in shape, having at least one lipid bilayer. Due to their hydrophobicity and/or hydrophilicity, biocompatibility, particle size and many other properties, liposomes can be used as drug delivery vehicles for administration of pharmaceutical drugs and nutrients, such as lipid nanoparticles in mRNA vaccines, and DNA vaccines. Liposomes can be prepared by disrupting biological membranes.
An S-layer is a part of the cell envelope found in almost all archaea, as well as in many types of bacteria. The S-layers of both archaea and bacteria consists of a monomolecular layer composed of only one identical proteins or glycoproteins. This structure is built via self-assembly and encloses the whole cell surface. Thus, the S-layer protein can represent up to 15% of the whole protein content of a cell. S-layer proteins are poorly conserved or not conserved at all, and can differ markedly even between related species. Depending on species, the S-layers have a thickness between 5 and 25 nm and possess identical pores 2–8 nm in diameter.
The University of Natural Resources and Life Sciences, Vienna, or simply BOKU, founded in 1872, is an education and research centre for renewable resources in Vienna, Austria. BOKU combines expertise in the fields of natural sciences, engineering and biotechnology as well as social and economic sciences. In research and teaching, it focuses on
Nanobiotechnology, bionanotechnology, and nanobiology are terms that refer to the intersection of nanotechnology and biology. Given that the subject is one that has only emerged very recently, bionanotechnology and nanobiotechnology serve as blanket terms for various related technologies.
Thermoproteus is a genus of archaeans in the family Thermoproteaceae. These prokaryotes are thermophilic sulphur-dependent organisms related to the genera Sulfolobus, Pyrodictium and Desulfurococcus. They are hydrogen-sulphur autotrophs and can grow at temperatures of up to 95 °C.
Erich Sackmann was a German experimental physicist and a pioneer of biophysics in Europe.
Cell theory has its origins in seventeenth century microscopy observations, but it was nearly two hundred years before a complete cell membrane theory was developed to explain what separates cells from the outside world. By the 19th century it was accepted that some form of semi-permeable barrier must exist around a cell. Studies of the action of anesthetic molecules led to the theory that this barrier might be made of some sort of fat (lipid), but the structure was still unknown. A series of pioneering experiments in 1925 indicated that this barrier membrane consisted of two molecular layers of lipids—a lipid bilayer. New tools over the next few decades confirmed this theory, but controversy remained regarding the role of proteins in the cell membrane. Eventually the fluid mosaic model was composed in which proteins “float” in a fluid lipid bilayer "sea". Although simplistic and incomplete, this model is still widely referenced today.
The cell membrane is a biological membrane that separates and protects the interior of a cell from the outside environment. The cell membrane consists of a lipid bilayer, made up of two layers of phospholipids with cholesterols interspersed between them, maintaining appropriate membrane fluidity at various temperatures. The membrane also contains membrane proteins, including integral proteins that span the membrane and serve as membrane transporters, and peripheral proteins that loosely attach to the outer (peripheral) side of the cell membrane, acting as enzymes to facilitate interaction with the cell's environment. Glycolipids embedded in the outer lipid layer serve a similar purpose. The cell membrane controls the movement of substances in and out of a cell, being selectively permeable to ions and organic molecules. In addition, cell membranes are involved in a variety of cellular processes such as cell adhesion, ion conductivity, and cell signalling and serve as the attachment surface for several extracellular structures, including the cell wall and the carbohydrate layer called the glycocalyx, as well as the intracellular network of protein fibers called the cytoskeleton. In the field of synthetic biology, cell membranes can be artificially reassembled.
The Methanosarcinales S-layer Tile Protein (MSTP) is a protein family found almost exclusively in Methanomicrobia members of the order Methanosarcinales. Typically a tandem repeat of two DUF1608 domains are contained in a single MSTP protein chain and these proteins self-assemble into the protective proteinaceous surface layer (S-layer) structure that encompasses the cell. The S-layer, which is found in most Archaea, and in many bacteria, serves many crucial functions including protection from deleterious extracellular substances.
Sporosarcina ureae is a type of bacteria of the genus Sporosarcina, and is closely related to the genus Bacillus. S. ureae is an aerobic, motile, spore-forming, Gram-positive coccus, originally isolated in the early 20th century from soil. S. ureae is distinguished by its ability to grow in relatively high concentrations of urea through production of at least one exourease, an enzyme that converts urea to ammonia. S. ureae has also been found to sporulate when environmental conditions become unfavorable, and can remain viable for up to a year.
A unilamellar liposome is a spherical liposome, a vesicle, bounded by a single bilayer of an amphiphilic lipid or a mixture of such lipids, containing aqueous solution inside the chamber. Unilamellar liposomes are used to study biological systems and to mimic cell membranes, and are classified into three groups based on their size: small unilamellar liposomes/vesicles (SUVs) that with a size range of 20–100 nm, large unilamellar liposomes/vesicles (LUVs) with a size range of 100–1000 nm and giant unilamellar liposomes/vesicles (GUVs) with a size range of 1–200 μm. GUVs are mostly used as models for biological membranes in research work. Animal cells are 10–30 μm and plant cells are typically 10–100 μm. Even smaller cell organelles such as mitochondria are typically 1–2 μm. Therefore, a proper model should account for the size of the specimen being studied. In addition, the size of vesicles dictates their membrane curvature which is an important factor in studying fusion proteins. SUVs have a higher membrane curvature and vesicles with high membrane curvature can promote membrane fusion faster than vesicles with lower membrane curvature such as GUVs.
Owais Mohammad is an Indian immunologist, nano-technologist and a professor at the interdisciplinary biotechnology unit of the Aligarh Muslim University. Known for his studies on nanotechnology-based vaccine and drug delivery, Owais is the author of two books, Trypanothione reductase: a potential anti-leishmanial drug target and Antimicrobial properties of clove oil: clove oils as antimicrobial agent. He has also co-edited two books, Modern Phytomedicine: Turning Medicinal Plants into Drugs and Combating Fungal Infections: Problems and Remedy, and has contributed chapters. His studies have also been documented by way of a number of articles and ResearchGate, an online repository of scientific articles has listed 60 of them. He is a recipient of the Rashtriya Gaurav Award of the India International Friendship Society. The Department of Biotechnology of the Government of India awarded him the National Bioscience Award for Career Development, one of the highest Indian science awards, for his contributions to biosciences in 2007. His work has been displayed on cover pages of FEMS Immunol. Med Microbiology for all the issues of Year 2006 and Molecular Medicine in May–June issue of Year 2007.
Shuguang Zhang is an American biochemist. He is at the MIT Media Lab's Laboratory for Molecular Architecture. Shuguang Zhang's research focuses on designs of biological molecules, particularly proteins and peptides. He has published over 170 scientific papers, which have cumulatively been cited over 35,000 times with an h-index of 88. On the “Updated science-wide author databases of standardizes citation indicators”, he is ranked 18th worldwide in the field of Biomedical Engineering. Zhang is also a co-founder and board member of Molecular Frontiers Foundation, which organizes annual Molecular Frontiers Symposia in Sweden and around the world. The selected winners are awarded Molecular Frontiers Inquiry Prize.
Intracellular delivery is the process of introducing external materials into living cells. Materials that are delivered into cells include nucleic acids, proteins, peptides, impermeable small molecules, synthetic nanomaterials, organelles, and micron-scale tracers, devices and objects. Such molecules and materials can be used to investigate cellular behavior, engineer cell operations or correct a pathological function.
Liangfang Zhang is a Chinese-American nanoengineer. He is the Chancellor Professor of Nanoengineering and Bioengineering and Director of Chemical Engineering at the University of California, San Diego. Zhang is a Fellow of the American Institute for Medical and Biological Engineering, American Association for the Advancement of Science, and the National Academy of Inventors.
Christoph Benning is a German–American plant biologist. He is an MSU Foundation Professor and University Distinguished Professor at Michigan State University. Benning's research into lipid metabolism in plants, algae and photosynthetic bacteria, led him to be named Editor-in-Chief of The Plant Journal in October 2008.
