‘Plug and play’ nanoparticles could make it easier to tackle various biological targets

Phys.org  October 30, 2023 Despite their inherent versatility and ability to enable complex biological applications, there is considerable interest in augmenting the performance of membrane-coated nanoparticles (CNP) through the introduction of additional functionalities. Researchers at UC San Diego developed and demonstrated a genetic-engineering-based modular approach to CNP functionalization. The cell membrane coating was engineered to express a SpyCatcher membrane anchor that could readily form a covalent bond with any moiety modified with SpyTag. They generated three unique targeted CNP formulations using different classes of targeting ligands, including a designed ankyrin repeat protein. In vitro, the modified nanoparticles exhibited enhanced affinity […]

Free-space nanoprinting beyond optical limits to create 4D functional structures

Phys.org October 7, 2023 Femtosecond laser–based technique called two-photon polymerization (TPP) has emerged as a powerful tool for nanofabrication and integrating nanomaterials. However, challenges persist in existing 3D nanoprinting methods, such as slow layer-by-layer printing and limited material options due to laser-matter interactions. An international team of researchers (USA – Purdue University, Germany, UK) has developed free-space nanopainting using an optical force brush (OFB) which enabled precise spatial writing paths, instantaneous adjustment of linewidths and concentrations, and unrestricted resolution beyond optical limits. OFB allowed rapid aggregation and solidification of radicals, resulting in narrower lines at lower polymerization thresholds and enhanced […]

Living hydrogel fibers unveiling a new era of sustainable engineered materials

Nanowerk  September 27, 2023 A major challenge in creating living materials for functional material design, integrating synthetic biology tools to endow materials with programmable, dynamic, and life-like characteristics, is balancing the tradeoff between structural stability, mechanical performance, and functional programmability. To address this problem researchers in China proposed a sheath–core living hydrogel fiber platform that synergistically integrated living bacteria with hydrogel fibers to achieve both functional diversity and structural and mechanical robustness. The microfluidic spinning was used to produce hydrogel fiber, which offered advantages in both structural and functional designability due to their hierarchical porous architectures that could be tailored […]

Tiny CRISPR tool could help shred viruses

Science Daily   September 27, 2023 The CRISPR-Cas13 ribonucleases have been widely applied for RNA knockdown and transcriptional modulation owing to their high programmability and specificity. However, the large size of Cas13 effectors and their non-specific RNA cleavage upon target activation limit the adeno-associated virus-based delivery of Cas13 systems for therapeutic applications. Researchers at Rice University descried detailed biochemical and structural characterizations of a compact Cas13 (Cas13bt3) suitable for adeno-associated virus delivery. Distinct from many other Cas13 systems, Cas13bt3 cleaves the target and other nonspecific RNA at internal “UC” sites and was activated in a target length-dependent manner. The cryo-electron microscope […]

Successful optical biosensing using dual optical combs: High sensitivity and rapid detection of biomolecules

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 […]

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 […]