Phys.org September 26, 2023 Rapid, sensitive detection of biomolecules is important for biosensing of infectious pathogens as well as biomarkers and pollutants. Researchers in Japan have achieved rapid and sensitive detection of SARS-CoV-2 nucleocapsid protein antigen by enhancing the performance of optical biosensing based on optical frequency combs (OFC). The virus-concentration-dependent optical spectrum shift produced by antigen–antibody interactions was transformed into a photonic RF shift by a frequency conversion between the optical and RF regions in the OFC, facilitating rapid and sensitive detection with well-established electrical frequency measurements. The active-dummy temperature-drift compensation with a dual-comb configuration enabled the very small […]
Category Archives: Biotechnology
In a First, Scientists Fully Wipe a Cell’s Memory Before Turning It Into a Stem Cell
Science Alert August 30, 2023 The epigenomes of hiPS cells and human embryonic stem (hES) cells differ significantly, which affects hiPS cell function. An international team of researchers (Australia, UK, Singapore) found that reprogramming-induced epigenetic aberrations to emerge midway through primed reprogramming, whereas DNA demethylation begins early in naive reprogramming. Using this they developed a transient-naive-treatment (TNT) reprogramming strategy that emulated the embryonic epigenetic reset. They showed that the epigenetic memory in hiPS cells is concentrated in cell of origin-dependent repressive chromatin. TNT reprogramming reconfigured these domains to a hES cell-like state and did not disrupt genomic imprinting correcting epigenetic […]
Turning bacteria into solar factories with semiconductor nanoclusters
Nanowerk July 28, 2023 Semiconductor-based biointerfaces are typically established either on the surface of the plasma membrane or within the cytoplasm. In Gram-negative bacteria, the periplasmic space, characterized by its confinement and the presence of numerous enzymes and peptidoglycans, offers additional opportunities for biomineralization, allowing for nongenetic modulation interfaces. A team of researchers in the US (University of Chicago, Argonne National Laboratory, National Renewal Energy Laboratory) demonstrated semiconductor nanocluster precipitation containing single- and multiple-metal elements within the periplasm. The periplasmic semiconductors were metastable and displayed defect-dominant fluorescent properties. The defect-rich (i.e., the low-grade) semiconductor nanoclusters produced in situ could still […]
Sticky, slippery, water repellent channels form maze-like, gravity-powered biomedical devices
Science Daily July 11, 2023 Motivated by the need to develop new point-of-care clinical tests researchers at Duke University developed a technology that only uses surface chemistry and gravity to manipulate the sequence, timing, movement, and interactions of discrete droplets across a surface solely by gravity. To demonstrate the application of the technology they fabricated a device that combined fluidic elements to carry out a multi-step enzymatic assay of LDH with minimal user intervention. To fabricate the device, they developed a surface coating toolbox of nine different coatings with three levels of wettability and three levels of slipperiness that could […]
Researchers induce cancer cells to ‘commit suicide’ with a self-produced bacterial toxin
Phys.org July 4, 2023 Suicide gene therapies and immunotoxins have been investigated for the treatment of tumors by direct cancer cell cytotoxicity. Recent advances in mRNA delivery also demonstrated the potential of mRNA-based vaccines and immune-modulators for cancer therapeutics by utilizing nanocarriers for mRNA delivery. Researchers in Israel designed a bacterial toxin-encoding modified mRNA, delivered by lipid nanoparticles into a B16-melanoma mouse model. They showed that local administration of LNPs entrapping a modified mRNA that encodes for a bacterial toxin, induced significant anti-tumor effects and improved overall survival of treated mice. They proposed mmRNA-loaded LNPs as a new class of […]
Innovative paper-like, battery-free, AI-enabled sensor for holistic wound monitoring
Nanowerk June 26, 2023 Researchers in Singapore developed a paper-like battery-free in situ AI-enabled multiplexed (PETAL) sensor for holistic wound assessment by leveraging deep learning algorithms. This sensor consisted of a wax-printed paper panel with five colorimetric sensors for temperature, pH, trimethylamine, uric acid, and moisture. Sensor images captured by a mobile phone were analyzed by neural network–based machine learning algorithms to determine healing status. For ex situ detection via exudates collected from rat perturbed wounds and burn wounds, the PETAL sensor could classify healing versus nonhealing status with an accuracy as high as 97%. With the sensor patches attached […]
MIT engineers develop a soft, printable, metal-free electrode
MIT News June 15, 2023 Conducting polymer hydrogels have emerged as a promising candidate for bioelectronic interfacing with biological systems. Despite the recent advances, the development of hydrogels with both excellent electrical and mechanical properties in physiological environments is still challenging. An international team of researchers led by MIT has developed a bi-continuous conducting polymer hydrogel that simultaneously achieves high electrical conductivity, stretchability, and fracture toughness in physiological environments. It is readily applicable to advanced fabrication methods including 3D printing. Enabled by these properties, they demonstrated multi-material 3D printing of monolithic all-hydrogel bioelectronic interfaces for long-term electrophysiological recording and stimulation […]
The ‘invisible’ cellulose coatings that mitigate surface transmission of pathogens
Phys.org May 17, 2023 Researchers in the UK have developed antimicrobial surface film based on sustainable micro fibrillated cellulose. The porosity, and microstructure of the film can be modulated by the formulations and the coating process. They observed a threefold reduction in water contact angles and accelerated water evaporation kinetics on the cellulose film (more than 50% faster than that on a flat glass surface). It exhibited a rapid inactivation effect against SARS-CoV-2 in 5 minutes, following deposition of virus-loaded droplets, and an exceptional ability to reduce contact transfer of liquid, e.g., respiratory droplets, to surfaces such as an artificial […]
Cell imaging could provide next step for developing synthetic photosynthesis
Phys.org April 5, 2023 Carboxysomes are proteinaceous bacterial microcompartments that sequester the key enzymes for carbon fixation in cyanobacteria and some proteobacteria. Despite their significance in carbon fixation and great bioengineering potentials, the structural understanding of native carboxysomes is currently limited to low-resolution studies. An international team of researchers (UK, Germany, Austria) has characterized a native α-carboxysome from a marine cyanobacterium by single-particle cryoelectron microscopy. They have determined the structure of its RuBisCO enzyme, and obtained low-resolution maps of its icosahedral shell, and its concentric interior organization. They proposed a complete atomic model of an intact carboxysome, providing insight into […]
This Incredible Tiny Robot Can Locate And Capture Individual Cells
Science Alert April 8, 2023 While dielectrophoretic (DEP)-based cargo manipulation can be achieved at high-solution conductivity, electrical propulsion of these micromotors becomes ineffective at solution conductivities. Researchers in Israel found that combination of a rotating magnetic field and electric field results in enhanced micromotor mobility and steering control through tuning of the electric field frequency. They demonstrated the micromotor’s ability of identifying apoptotic cell among viable and necrotic cells based on their dielectrophoretic difference. This enabled analysis of apoptotic status in the single-cell samples for drug discovery, cell therapeutics, and immunotherapy. According to the researcher’s hybrid micromotor approach for label-free […]