Biology subjects

Booth, M. J.

Publications and source records attributed to Booth, M. J..

At least 19 recordsLinked to original sources

bioRxiv2026

Programmable and Dynamic DNA Localisation at Synthetic Cell Membranes

Spatial and temporal organisation of membrane-associated components is fundamental to cellular signalling, yet remains difficult to engineer in minimal synthetic systems. In synthetic cells, DNA and RNA nanotechnology offer programmable molecular organisation at membranes, while in vitro transcription (IVT) enables gene expression-driven regulation. However, integrating these systems within cell-like compartments, such as giant unilamellar vesicles (GUVs), remains challenging due to undesirable interactions between transcription machinery and nucleic acid assemblies. Here, we present a modular strategy that couples in situ RNA production to dynamic DNA localisation at GUV synthetic cell membranes. RNA strands, transcribed within GUVs, function as linkers that recruit DNA-conjugated cargo to lipid membranes, enabling programmable spatial organisation. Using this framework, we achieved reversible membrane localisation through toehold-mediated strand displacement and RNase H-mediated degradation. This work establishes a gene expression-driven platform for programmable and dynamic control of membrane-associated components in synthetic cells, providing a foundation for constructing dynamic signalling assemblies and higher-order cellular behaviours. O_FIG O_LINKSMALLFIG WIDTH=191 HEIGHT=200 SRC="FIGDIR/small/738173v1_ufig1.gif" ALT="Figure 1"> View larger version (58K): org.highwire.dtl.DTLVardef@1d6dbc4org.highwire.dtl.DTLVardef@f6419aorg.highwire.dtl.DTLVardef@14cff99org.highwire.dtl.DTLVardef@20b95a_HPS_FORMAT_FIGEXP M_FIG C_FIG

synthetic biology↗

bioRxiv2025

The effect of PEGylation on surface tethering of liposomes via DNA nanotechnology.

Polyethylene glycol (PEG) is widely used in liposome formulation due to its blocking properties and ability to prolong circulation in vivo, to create biomimetic liposomes and drug delivery devices. Similarly, membrane-embedded DNA nanotechnology is increasingly used to modulate cellular behaviour and communication. However, there is a gap in knowledge in how PEG-lipid formulations can be optimised for both liposome properties and control of selective DNA hybridisation. To address this, we systematically investigated the effect of liposome PEG content on DNA mediated tethering of liposomes to glass surfaces. We formulated liposomes of two different lipid compositions (DOPE/DOPC or DPhPC), with varying amounts of PEGylated lipid (0-50%). We measured the effect of increased PEG content on liposome size and polydispersity through dynamic light scattering (DLS). Small amounts of PEG (0-20%) introduced repulsive forces that reduced size, while large amounts of PEG (30-50%) increased polydispersity. PEG-liposomes were then decorated with cholesterol-DNA strands and labelled with either intercalating lipid dyes or fluorescently labelled lipids. Binding to surfaces via complementary DNA strands was quantified using total internal reflection fluorescence (TIRF) microscopy. We found that PEGylation of DNA-liposomes could either block or enhance surface binding, depending on the amount of PEG. DNA-liposomes with reduced surface binding included DPhPC/DiD with 10% or 20% PEG-lipid. In contrast, DNA-liposome surface binding increased for DOPE/DOPC/DiD with increasing PEG%. This study highlights that while PEG can act to stabilise liposome formulations, its ability to block specific DNA binding interactions on membranes is variable and dependent on membrane composition. Table of contents figure O_FIG O_LINKSMALLFIG WIDTH=197 HEIGHT=200 SRC="FIGDIR/small/663613v1_ufig1.gif" ALT="Figure 1"> View larger version (55K): org.highwire.dtl.DTLVardef@183b215org.highwire.dtl.DTLVardef@1208fd6org.highwire.dtl.DTLVardef@c343ccorg.highwire.dtl.DTLVardef@1982f80_HPS_FORMAT_FIGEXP M_FIG C_FIG

biophysics↗

bioRxiv2025

Deep three-photon functional imaging in the mouse cortex with adaptive optics

Three-photon (3P) microscopy enables functional non-invasive single-cell resolution imaging at greater depths than any other technique. A key challenge of deep imaging is tissue-induced optical aberration, which reduces the excitation confinement. Adaptive optics use deformable mirrors to compensate for optical distortions, hence correcting these aberrations. Here, we present a practical adaptive optics-assisted 3P imaging system for functional imaging in the mouse brain during behavior. We introduce hierarchical corrections that sequentially target aberrations caused by the microscope system, the cranial window, and tissue depth. We demonstrate the utility of this strategy in the prelimbic cortex, where large vasculature near the midline causes aberrations, and in the lateral somatosensory cortex, where side access leads to distinct wavefront distortions. In both regions, adaptive optics significantly improved imaging performance, restoring cellular visibility near vasculature and enhancing signal-to-noise ratio. Our work provides a practical framework for utilizing adaptive optics to improve 3P imaging during behavior.

neuroscience↗

bioRxiv2025

Wavefront estimation through structured detection in laser scanning microscopy

Laser scanning microscopy (LSM) is the base of numerous advanced imaging techniques, including confocal laser scanning microscopy (CLSM), a widely used tool in life sciences research. However, its effective resolution is often compromised by optical aberrations, a common challenge in all optical systems. While adaptive optics (AO) can correct these aberrations, current methods face significant limitations: Aberration estimation, which is central to any AO approach, typically requires specialized hardware or prolonged sample exposure, rendering these methods sample-invasive, and less user-friendly. In this study, we introduce a simple and efficient AO approach for CLSM systems equipped with a detector array - the same of super-resolved image-scanning microscopy - and an AO element for beam shaping. We demonstrate that imaging datasets acquired with a detector array inherently encode aberration information. Leveraging this property, we developed a custom convolutional neural network capable of decoding aberrations, up to the 11th Zernike coefficient, directly from a single acquisition. This method enables a new generation of AO implementations for LSM, offering an accessible solution that minimizes sample stress while achieving high-resolution, and aberration-free imaging.

bioengineering↗

bioRxiv2024

Magnetic Activation of Spherical Nucleic Acids for the Remote Control of Synthetic Cells

The advancement of synthetic cells as drug delivery devices hinges on the development of targeting strategies, in particular the controlled synthesis of biomolecules in-situ using a deeply penetrative stimulus. To address this, we have designed spherical nucleic acids comprising DNA promoter sequences decorating magnetic nanoparticle cores. By harnessing the heat dissipated from magnetic hyperthermia (a clinically-approved anticancer therapy) we tightly controlled cell-free protein synthesis. We then deployed a tissue phantom that is impenetrable by current activation methods to demonstrate the potential of this technology for the remote control of synthetic cells using deeply tissue-penetrating magnetic fields. This paves the way for targeting and controlling the in-situ synthesis of biomolecules deep within the body. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=181 SRC="FIGDIR/small/608917v1_ufig1.gif" ALT="Figure 1"> View larger version (46K): org.highwire.dtl.DTLVardef@3cf352org.highwire.dtl.DTLVardef@18a8da3org.highwire.dtl.DTLVardef@159018aorg.highwire.dtl.DTLVardef@744529_HPS_FORMAT_FIGEXP M_FIG C_FIG

synthetic biology↗

bioRxiv2024

Lysosomal signalling pathways influence heart rhythm, and regulate atrial function

In the heart, endogenous nicotinic acid adenine dinucleotide phosphate (NAADP) triggers lysosomal calcium (Ca2+) release to augment sarcoplasmic reticulum (SR) Ca2+ sequestration, producing larger Ca2+ transients. However, the role of lysosomal Ca2+ signals in pacemaker activity, a distinct Ca2+-operated function of the sinoatrial node (SAN), or in the atrial myocardium has not been investigated. Pharmacological or genetic ablation of the NAADP pathway inhibits the spontaneous beating rate response to beta-adrenergic stimulation in intact SAN. We found intracellular signaling microdomains between lysosomes and neighboring SR or mitochondria in mouse, and goat tissue. The spatial relationship between lysosomes and other Ca2+-handling organelles are altered in goat atrial fibrillation. Furthermore, we demonstrate atrial myocytes produce cAMP in response to lysosomal signaling, adding a novel trigger for cyclic nucleotide signaling. Our findings support the hypothesis that lysosomal Ca2+ signaling contributes to regulation of cardiomyocyte cAMP levels and pacemaker activity.

physiology↗

bioRxiv2023

Sequence-independent, site-specific incorporation of chemical modifications to generate light-activated plasmids

Plasmids are ubiquitous in biology, where they are used to study gene-function relationships and intricate molecular networks, and hold potential as therapeutic devices. Developing methods to control their function will advance their application in research and may also expedite their translation to clinical settings. Light is an attractive stimulus to conditionally regulate plasmid expression as it is non-invasive, and its properties such as wavelength, intensity, and duration can be adjusted to minimise cellular toxicity and increase penetration. Herein, we have developed a method to site-specifically introduce photocages into plasmids, by resynthesizing one strand in a manner similar to Kunkel mutagenesis. Unlike alternative approaches to chemically-modify plasmids, this method is sequence independent at the site of modification and uses commercially available phosphoramidites. To generate our light-activated (LA) plasmids, photocleavable biotinylated nucleobases were introduced at specific sites across the T7 and CMV promoters on plasmids and bound to streptavidin to sterically block access. These LA-plasmids were then successfully used to control expression in both cell-free systems (T7 promoter) and mammalian cells (CMV promoter). These light-activated plasmids might be used to remotely-control cellular activity and reduce off-target toxicity for future medical use. Our simple approach to plasmid modification might also be used to introduce novel chemical moieties for advanced function. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=50 SRC="FIGDIR/small/542478v1_ufig1.gif" ALT="Figure 1"> View larger version (12K): org.highwire.dtl.DTLVardef@256978org.highwire.dtl.DTLVardef@2f7ecdorg.highwire.dtl.DTLVardef@2dd957org.highwire.dtl.DTLVardef@1802bf_HPS_FORMAT_FIGEXP M_FIG C_FIG

synthetic biology↗

bioRxiv2023

Sculpting DNA-based synthetic cells through phase separation and phase-targeted activity

Synthetic cells, like their biological counterparts, require internal compartments with distinct chemical and physical properties where different functionalities can be localised. Inspired by membrane-less compartmentalisation in biological cells, here we demonstrate how micro-phase separation can be used to engineer heterogeneous cell-like architectures with programmable morphology and compartment-targeted activity. The synthetic cells selfassemble from amphiphilic DNA nanostructures, producing core-shell condensates due to size-induced de-mixing. Lipid deposition and phase-selective etching are then used to generate a porous pseudo-membrane, a cytoplasm analogue, and membrane-less organelles. The synthetic cells can sustain RNA synthesis via in vitro transcription, leading to cytoplasm and pseudo-membrane expansion caused by an accumulation of the transcript. Our approach exemplifies how architectural and functional complexity can emerge from a limited number of distinct building blocks, if molecular-scale programmability, emergent biophysical phenomena, and biochemical activity are coupled to mimic those observed in live cells.

biophysics↗

bioRxiv2022

Engineering cellular communication between light-activated synthetic cells and bacteria

Gene-expressing compartments assembled from simple, modular parts, are a versatile platform for creating minimal synthetic cells. In a manner synonymous with natural cells, these life-like assemblies utilise information encoded in DNA within the compartments interior to dictate which proteins are expressed and consequently the overall function of the synthetic cell. Hence, by incorporating gene regulatory motifs into the DNA templates, in situ gene expression can be controlled according to specific stimuli. In this work, cell-free protein synthesis within synthetic cells was controlled using light by encoding genes of interest on light-activated DNA templates. Light-activated DNA contained a photocleavable blockade within the T7 promoter region that tightly repressed transcription until the blocking groups were removed with UV light. In this way, synthetic cells were activated remotely, in a spatiotemporally controlled manner. By applying this strategy to the expression of an acyl homo-serine lactone synthetase, BjaI, quorum-sensing based communication between synthetic cells and bacteria was controlled with light. This work provides a framework for the remote-controlled production and delivery of small molecules from non-living matter to living matter, with applications in biology and medicine.

synthetic biology↗

bioRxiv2022

Reaction-diffusion patterning of DNA-based artificial cells

Biological cells display complex internal architectures, with distinct micro environments that establish the chemical heterogeneity needed to sustain cellular functions. The continued efforts to create advanced cell mimics - artificial cells - demands strategies to construct similarly heterogeneous structures with localized functionalities. Here, we introduce a platform for constructing membrane-less artificial cells from the self-assembly of synthetic DNA nanostructures, in which internal domains can be established thanks to prescribed reaction-diffusion waves. The method, rationalized through numerical modeling, enables the formation of up to five distinct, concentric environments, in which functional moieties can be localized. As a proof-of-concept, we apply this platform to build DNA-based artificial cells in which a prototypical nucleus synthesizes fluorescent RNA aptamers, which then accumulate in a surrounding storage shell, thus demonstrating spatial segregation of functionalities reminiscent of that observed in biological cells.

synthetic biology↗

bioRxiv2021

A lipid-based parallel processor for chemical signals

A key goal of bottom-up synthetic biology is to construct cell- and tissue-like structures. Underpinning cellular life is the ability to process several external chemical signals, often in parallel. Until now, however, cell- and tissue-like structures have only been constructed with one signalling pathway. Here, we construct a dual-signal processor from the bottom up in a modular fashion. The processor comprises three aqueous compartments bounded by lipid bilayers and operates in an aqueous environment. It can receive two chemical signals from the external environment, process them orthogonally, and then produce a distinct output for each signal. It is suitable for both sensing and enzymatic processing of environmental signals with fluorescence and molecular outputs. In the future, such processors could serve as smart drug delivery vehicles or as modules within synthetic tissues to control their behaviour in response to external chemical signals.

synthetic biology↗

bioRxiv2021

Python-Microscope: high performance control of arbitrarily complex and scalable bespoke microscopes

Custom built microscopes often require control of multiple hardware devices and precise hardware coordination. It is also desirable to have a solution that is scalable to complex systems and translatable between components from different manufacturers. Here we report Python-Microscope, a free and open source Python library for high performance control of arbitrarily complex and scalable custom microscope systems. Python-Microscope offers simple to use Python-based tools, abstracting differences between physical devices by providing a defined interface for different device types. Concrete implementations are provided for a range of specific hardware and a framework exists for further expansion. Python-Microscope supports the distribution of devices over multiple computers while maintaining synchronisation via highly precise hardware triggers. We discuss the architecture choices of Python-Microscope that overcome the performance problems often raised against Python and demonstrate the different use cases that drove its design: its integration in user facing projects, namely in the Microscope-Cockpit project; in controlling complex microscopes at high speed while using the Python programming language; and as a microscope simulation tool for software development.

biophysics↗

bioRxiv2021

Microscope-Cockpit: Python-based bespoke microscopy for bio-medical science

We have developed "Microscope-Cockpit" (Cockpit), a highly adaptable open source user-friendly Python-based GUI environment for precision control of both simple and elaborate bespoke microscope systems. The user environment allows next-generation near-instantaneous navigation of the entire slide landscape for efficient selection of specimens of interest and automated acquisition without the use of eyepieces. Cockpit uses "Python-Microscope" (Microscope) for high-performance coordinated control of a wide range of hardware devices using open source software. Microscope also controls complex hardware devices such as deformable mirrors for aberration correction and spatial light modulators for structured illumination via abstracted device models. We demonstrate the advantages of the Cockpit platform using several bespoke microscopes, including a simple widefield system and a complex system with adaptive optics and structured illumination. A key strength of Cockpit is its use of Python, which means that any microscope built with Cockpit is ready for future customisation by simply adding new libraries, for example machine learning algorithms to enable automated microscopy decision making while imaging. HighlightsO_LIUser-friendly setup and use for simple to complex bespoke microscopes. C_LIO_LIFacilitates collaborations between biomedical scientists and microscope technologists. C_LIO_LITouchscreen for near-instantaneous navigation of specimen landscape. C_LIO_LIUses Python-Microscope, for abstracted open source hardware device control. C_LIO_LIWell-suited for user training of AI-algorithms for automated microscopy. C_LI

biophysics↗

bioRxiv2020

3D Adaptive Optical Nanoscopy for Thick Specimen Imaging at sub-50 nm Resolution

Understanding cellular organization demands the best possible spatial resolution in all three dimensions (3D). In fluorescence microscopy, this is achieved by 4Pi nanoscopy methods that combine the concepts of using two opposing objectives for optimal diffraction-limited 3D resolution with switching fluorescent molecules between bright and dark states to break the diffraction limit. However, optical aberrations have limited these nanoscopes to thin samples and prevented their application in thick specimens. Here, we have developed a nanoscope that, by utilizing an advanced adaptive optics strategy, achieves sub-50 nm isotropic resolution of structures such as neuronal synapses and ring canals previously inaccessible in tissue.

biophysics↗

bioRxiv2020

Wavefront-sensorless adaptive optics with a laser-free spinning disk confocal microscope

Adaptive optics is being applied widely to a range of microscopies in order to improve imaging quality in the presence of specimen-induced aberrations. We present here the first implementation of wavefront-sensorless adaptive optics for a laser-free, aperture correlation, spinning disk microscope. This widefield method provides confocal-like optical sectioning through use of a patterned disk in the illumination and detection paths. Like other high-resolution microscopes, its operation is compromised by aberrations due to refractive index mismatch and variations within the specimen. Correction of such aberrations shows improved signal level, contrast and resolution.

cell biology↗

bioRxiv2020

Microscope-AOtools: A generalised adaptive optics implementation

Microscope-AOtools is a software package which allows for a simple, robust and generalised implementation of adaptive optics (AO) elements. It contains all the necessary methods for set-up, calibration, and aberration correction which are simple to use and function in a robust manner. Aberrations arising from sources such as sample hetero-geneity and refractive index mismatches are constant problems in biological imaging. These aberrations reduce image quality and the achievable depth of imaging, particularly in super-resolution microscopy techniques. AO technology has been proven to be effective in correcting for these aberrations and thereby improving the image quality. However, it has not been widely adopted by the biological imaging community due, in part, to difficulty in set-up and operation of AO, particularly by non-specialist users. Microscope-AOtools offers a robust, easy-to-use implementation of the essential methods for set-up and use of AO techniques. These methods are constructed in a generalised manner that can utilise a range of adaptive optics elements, wavefront sensing techniques and sensorless AO correction methods. Furthermore, the methods are designed to be easily extensible as new techniques arise, leading to a streamlined pipeline for new AO technology and techniques to be adopted by the wider microscopy community.

biophysics↗

bioRxiv2020

Democratising "Microscopi": a 3D printed automated XYZT fluorescence imaging system for teaching, outreach and fieldwork

Commercial fluorescence microscope stands and fully automated XYZt fluorescence imaging systems are generally beyond the limited budgets available for teaching and outreach. We have addressed this problem by developing "Microscopi", an accessible, affordable, DIY automated imaging system that is built from 3D printed and commodity off-the-shelf hardware, including electro-mechanical, computer and optical components. Our design features automated sample navigation and image capture with a simple web-based graphical user interface, accessible with a tablet or other mobile device. The light path can easily be switched between different imaging modalities. The open source Python-based control software allows the hardware to be driven as an integrated imaging system. Furthermore, the microscope is fully customisable, which also enhances its value as a learning tool. Here, we describe the basic design and demonstrate imaging performance for a range of easily sourced specimens. HighlightsO_LIPortable, low cost, self-build from 3D printed and commodity components C_LIO_LIMultimodal imaging: bright field, dark field, pseudo-phase and fluorescence C_LIO_LIAutomated XYZt imaging from a tablet or smartphone via a simple GUI C_LIO_LIWide ranging applications in teaching, outreach and fieldwork C_LIO_LIOpen source hardware and software design, allowing user modification C_LI

scientific communication and education↗

bioRxiv2020

Compact and contactless reflectance confocal microscope for neurosurgery

Visual guidance at the cellular level during neurosurgical procedures is essential for complete tumour resection. We present a compact reflectance confocal microscope with a 20 mm working distance that provided <1.2 {micro}m spatial resolution over a 600 {micro}m x 600 {micro}m field of view in the near-infrared region. A physical footprint of 200 mm x 550 mm was achieved using only standard off-the-shelf components. Theoretical performance of the optical design was first evaluated via commercial Zemax software. Then three specimens from rodents: fixed brain, frozen calvaria and live hippocampal slices, were used to experimentally assess system capability and robustness. Results show great potential for the proposed system to be translated into use as a next generation label-free and contactless neurosurgical microscope.

neuroscience↗