Thus, they have been extensively investigated during the last decade. Natural biomacromolecules such as bovine serum albumin (BSA) have conventionally been used to block cell adhesion. Zhao and Ding (Fudan University, Shanghai, China) recently reported that the purple membrane (PM) containing a natural photoresponsive protein, bacteriorhodopsin (BR), can serve as a new basic substance that resists adhesion of mammalian cells.
Purple membrane containing the retinal protein bacteriorhodopsin (BR) was coated onto glass. The coated film resisted adhesion of mammalian cells, while the purple membrane retained its biological activity. This is the first report of a non-fouling substrate with photoelectric and photochromic responses. This material consists of natural biomacromolecules. Credit: © Science China Press
BR is a retinal-containing bacterial protein that is present in the PM region of the bacterial membrane. The PM is the simplest biological system for energy conversion. Excitation of BR with a photon causes a photocycle, resulting in uptake of a proton from the cytoplasmic side of the PM and release of another proton to the extracellular side. BR and similar retinal proteins have attracted much attention as potential optical materials for applications in 2-D or 3-D storage, holographic storage, optical filtering, light switching, neural networks, super-fast photo detection, motion detection, and artificial retinas, etc., and also as model proteins in fundamental research.
Nevertheless, the PM had not been recognized as a non-fouling material for preventing cell adhesion. Adhesion is the first cellular event that occurs when a cell comes into contact with a material surface, and it influences subsequent cellular events such as proliferation and differentiation. Non-fouling surfaces are useful for studies on cell–material interactions for generating patterned surfaces of contrasting adhesion, and they are also useful for controlling cellular and bacterial adhesion in medical applications and/or in complex bio-related environments. A number of non-fouling substances have been reported, including polyethylene glycol (PEG) or oligoethylene glycol (OEG), PEG hydrogels, poly(N-isopropylacrylamide) or its copolymers, and the globular protein, BSA. This study affords a new choice of non-fouling substance, because the PM containing the membrane protein BR was shown to resist cell adhesion.
Our results reveal that the natural PM has significant resistance to cell adhesion. This non-fouling property is very beneficial for potential applications of BR materials, for instance, as biosensors in complex environments. The finding also affords an excellent model substance that resists cell adhesion, which could be useful in surface modification of biomaterials for regenerative medicine. The photoresponsive property of BR distinguishes it from all of the currently known anti-fouling substances.
It is also worth noting that many other retinal proteins such as rhodopsin, halorhodopsin, xanthorhodopsin, and archaerhodopsin, are light-driven ion pumps. Therefore, a direct extension of this work would be to examine possible non-fouling properties of other retinal proteins. Further studies are required examine the resistance to adhesion of other types of mammalian and non-mammalian cells. Hence, while the mechanism by which the PM prevents non-specific protein absorption remains an open question, this report paves the way for further investigations and new applications of BR and possibly other light-sensitive proteins.Reference
Ding Jian-dong | EurekAlert!
Novel mechanisms of action discovered for the skin cancer medication Imiquimod
21.10.2016 | Technische Universität München
Second research flight into zero gravity
21.10.2016 | Universität Zürich
Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.
"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...
In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.
A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...
By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.
"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...
COMPAMED has become the leading international marketplace for suppliers of medical manufacturing. The trade fair, which takes place every November and is co-located to MEDICA in Dusseldorf, has been steadily growing over the past years and shows that medical technology remains a rapidly growing market.
In 2016, the joint pavilion by the IVAM Microtechnology Network, the Product Market “High-tech for Medical Devices”, will be located in Hall 8a again and will...
'Ferroelectric' materials can switch between different states of electrical polarization in response to an external electric field. This flexibility means they show promise for many applications, for example in electronic devices and computer memory. Current ferroelectric materials are highly valued for their thermal and chemical stability and rapid electro-mechanical responses, but creating a material that is scalable down to the tiny sizes needed for technologies like silicon-based semiconductors (Si-based CMOS) has proven challenging.
Now, Hiroshi Funakubo and co-workers at the Tokyo Institute of Technology, in collaboration with researchers across Japan, have conducted experiments to...
14.10.2016 | Event News
14.10.2016 | Event News
12.10.2016 | Event News
21.10.2016 | Health and Medicine
21.10.2016 | Information Technology
21.10.2016 | Materials Sciences