Science Daily March 20, 2024 Extracellular electron transfer (EET) via microbial nanowires drives important environmental processes and biotechnological applications for bioenergy, bioremediation, and bioelectronics. However, the process is not clear. An international team of researchers (USA – Yale University, Portugal) showed that Geobacter sulfurreducens periplasmic cytochromes PpcABCDE inject electrons directly into OmcS nanowires by binding transiently with differing efficiencies, with the least-abundant cytochrome (PpcC) showing the highest efficiency. This defined nanowire-charging pathway was evolutionarily conserved in phylogenetically diverse bacteria capable of EET. OmcS heme reduction potentials were within 200 mV of each other, with a midpoint 82 mV-higher than reported previously. […]
Tag Archives: Biotechnology
Researchers demonstrate control of living cells with electronics
Phys.org March 5, 2024 Microelectronic devices can directly communicate with biology, as electronic information can be transmitted via redox reactions within biological systems. Researchers at the University of Maryland engineered biology’s native redox networks to enable electronic interrogation and control of biological systems at several hierarchical levels: proteins, cells, and cell consortia. Electro-biofabrication facilitated on-device biological component assembly, electrode-actuated redox data transmission and redox-linked synthetic biology allowed programming of enzyme activity and closed-loop electrogenetic control of cellular function. Horseradish peroxidase was assembled onto interdigitated electrodes where electrode-generated hydrogen peroxide controlled its activity. E. coli’s stress response regulon, oxyRS, was rewired […]
Silk nanointerfaces merge biology and electronics
Nanowerk October 24, 2023 Researchers at Tufts University have developed a hybrid biopolymer–semiconductor device by integrating nanoscale silk layers in a well-established class of inorganic field-effect transistors (silk-FETs). The devices offered two distinct modes of operation—either traditional field-effect or electrolyte-gated—enabled by the precisely controlled thickness, morphology, and biochemistry of the integrated silk layers. The different operational modes were selectively accessed by dynamically modulating the free-water content within the nanoscale protein layer from the vapor phase. They illustrated the utility of the hybrid devices in a highly sensitive and ultrafast breath sensor, highlighting the opportunities offered by the integration of nanoscale […]
New laser tweezers allow gentle, efficient manipulation of cells and nanoparticles (w/video)
Nanowerk September 8, 2023 Optical tweezers are used from manufacturing to biotechnology. However, the requirement of refractive index contrast and high laser power results in potential photon and thermal damage to the trapped objects. Optothermal tweezers have been developed to trap particles and biological cells via opto-thermophoresis with much lower laser powers. But the intense laser heating and stringent requirement of the solution environment prevent their use for general biological applications. A team of researchers in the US (UT Austin, UT Dallas) has proposed hypothermal opto-thermophoretic tweezers (HOTTs) to achieve low-power trapping of diverse colloids and biological cells in their […]
Tiny magnetic beads produce an optical signal that could be used to quickly detect pathogens
MIT News August 25, 2023 Researchers at MIT have identified a new optical signature in a widely used class of magnetic beads, which could be used to quickly detect contaminants in a variety of diagnostic tests. They used Dynabeads coated with anti-Salmonella to bind and identify Salmonella enterica. Dynabeads presented signature peaks at 1000 and 1600 1/cm from aliphatic and aromatic C-C stretching of polystyrene, and 1350 1/cm and 1600 1/cm from amide, alpha-helix, and beta-sheet of antibody coatings of the Fe2O3 core, confirming with electron dispersive X-ray imaging. The Raman signature could be measured in dry and liquid samples. […]
Researchers design switch-like proteins inspired by transistors
Phys.org August 23, 2023 In nature, proteins that switch between two conformations in response to environmental stimuli structurally transduce biochemical information in a manner analogous to how transistors control information flow in computing devices. Designing proteins with two distinct but fully structured conformations is a challenge for protein design as it requires sculpting an energy landscape with two distinct minima. A team of researchers in the US (University of Washington, Lawrence Berkeley National Laboratory, University of Milwaukee) described the design of “hinge” proteins that populate one designed state in the absence of ligand and a second designed state in the […]
Discovering nanomachines within living organisms: Cytochromes P450 unleashed as living soft robots
Phys.org August 7, 2023 An international team of researchers (Israel, India) addressed the difference between regular 3D matter and the nanomachines in ‘living matters’ (e.g., the CYP450 enzymes), which oxidize an array of essential substrate molecules. Molecular dynamics simulations revealed that, unlike 3D materials, CYP450s are 4D nanomachines, in which the fourth dimension was a sensing mechanism whereby the protein responds to an initial stimulus of substrate entrance and performs an autonomous chain of events (the catalytic cycle), which leads to substrate oxidation. They found that stimulus was the binding of a substrate molecule that eventually underwent oxidation in a […]
Bacteria as blacksmiths – new method to assemble unconventional materials
Nanowerk July 27, 2023 When in equilibrium, thermal forces agitate molecules, which then diffuse, collide, and bind to form materials. However, the space of accessible structures in which micron-scale particles can be organized by thermal forces is limited, owing to the slow dynamics and metastable states. Active agents in a passive fluid generate forces and flows, forming a bath with active fluctuations. Two unanswered questions are whether those active agents can drive the assembly of passive components into unconventional states and which material properties they will exhibit. Researchers in Austria showed that passive, sticky beads immersed in a bath of […]
Intelligent rubber materials
Nanowerk July 18, 2023 Researchers in Germany have developed intelligent humidity-programmed hydrogel patches with high stretchability and tunable water-uptake and -release by copolymerization and crosslinking of N-isopropylacrylamide and oligo(ethylene glycol) comonomers. The intelligent elastomeric patches strongly responded to different humidities and temperatures in terms of mechanical properties which made them applicable for soft robotics and smart skin applications where autonomous adaption to environmental conditions was a key requirement. Beyond using the hydrogel in the conventional state in aqueous media, the new patches could be controlled by relative humidity. The humidity programming of the patches allowed to tune drug release kinetics, […]
Using AI, scientists find a drug that could combat drug-resistant infections
MIT News May 25, 2023 Discovering new antibiotics against Acinetobacter baumannii, a pathogen that often displays multidrug resistance has proven challenging through conventional screening approaches. An international team of researchers (Canada, USA – MIT, Harvard University) screened ~7,500 molecules for those that inhibited the growth of A. baumannii in vitro and trained a neural network with this growth inhibition dataset and performed in silico predictions for structurally new molecules with activity against A. baumannii. They discovered abaucin, an antibacterial compound with narrow-spectrum activity against A. baumannii. Further investigations revealed that abaucin perturbs lipoprotein trafficking, and it could control an A. […]