ACS Appl Mater Interfaces
January 2024
Extracellular matrices interface with cells to promote cell growth and tissue development. Given this critical role, matrix mimetics are introduced to enable biomedical materials ranging from tissue engineering scaffolds and tumor models to organoids for drug screening and implant surface coatings. Traditional microscopy methods are used to evaluate such materials in their ability to support exploitable cell responses, which are expressed in changes in cell proliferation rates and morphology.
View Article and Find Full Text PDFExtracellular matrix type 0 is reported. The matrix is developed from a jellyfish collagen predating mammalian forms by over 0.5 billion years.
View Article and Find Full Text PDFAnnually, an estimated seven million deaths are linked to exposure to airborne pollutants. Despite extensive epidemiological evidence supporting clear associations between poor air quality and a range of short- and long-term health effects, there are considerable gaps in our understanding of the specific mechanisms by which pollutant exposure induces adverse biological responses at the cellular and tissue levels. The development of more complex, predictive, respiratory models, including two- and three-dimensional cell cultures, spheroids, organoids and tissue cultures, along with more realistic aerosol exposure systems, offers new opportunities to investigate the cytotoxic effects of airborne particulates under controlled laboratory conditions.
View Article and Find Full Text PDFThe emergence of multidrug-resistant bacteria stimulates the search for antimicrobial materials capable of addressing challenges conventional antibiotics fail to address. The ability to target intracellular bacteria remains one of the most fundamental tasks for contemporary antimicrobial treatments. Here we report engineered protein pseudo-capsids targeting bacteria internalised in macrophages.
View Article and Find Full Text PDFElectron microscopy offers necessary precision for the characterization of peptide materials at the nanoscale. Analysis is typically performed for acellular material specimens, whereas measurements in more complex, cellular environments prompt additional considerations for sample processing. Herein, we describe a protocol for the ultramicrotomy analysis of peptide-treated bacterial and mammalian cells.
View Article and Find Full Text PDFFront Bioeng Biotechnol
January 2020
The symptomatic irreproducibility of data in biomedicine and biotechnology prompts the need for higher order measurements of cells in their native and near-native environments. Such measurements may support the adoption of new technologies as well as the development of research programs across different sectors including healthcare and clinic, environmental control and national security. With an increasing demand for reliable cell-based products and services, cellular metrology is poised to help address current and emerging measurement challenges faced by end-users.
View Article and Find Full Text PDFA design template for membrane active antibiotics against microbial and tumor cells is described. The template is an amino acid sequence that combines the properties of helminth defense molecules, which are not cytolytic, with the properties of host-defense peptides, which disrupt microbial membranes. Like helminth defense molecules, the template folds into an amphipathic helix in both mammalian host and microbial phospholipid membranes.
View Article and Find Full Text PDFA correction to this article has been published and is linked from the HTML and PDF versions of this paper. The error has been fixed in the paper.
View Article and Find Full Text PDFThe spread of antimicrobial resistance stimulates discovery strategies that place emphasis on mechanisms circumventing the drawbacks of traditional antibiotics and on agents that hit multiple targets. Host defense peptides (HDPs) are promising candidates in this regard. Here we demonstrate that a given HDP sequence intrinsically encodes for tuneable mechanisms of membrane disruption.
View Article and Find Full Text PDFThe spread of bacterial resistance to antibiotics poses the need for antimicrobial discovery. With traditional search paradigms being exhausted, approaches that are altogether different from antibiotics may offer promising and creative solutions. Here, we introduce a de novo peptide topology that-by emulating the virus architecture-assembles into discrete antimicrobial capsids.
View Article and Find Full Text PDFThe spread of bacterial resistance to traditional antibiotics continues to stimulate the search for alternative antimicrobial strategies. All forms of life, from bacteria to humans, are postulated to rely on a fundamental host defense mechanism, which exploits the formation of open pores in microbial phospholipid bilayers. Here we predict that transmembrane poration is not necessary for antimicrobial activity and reveal a distinct poration mechanism that targets the outer leaflet of phospholipid bilayers.
View Article and Find Full Text PDFExtracellular protein matrices provide a rigidity interface exhibiting nano-mechanical cues that guide cell growth and proliferation. Cells sense such cues using actin-rich filopodia extensions which encourage favourable cell-matrix contacts to recruit more actin-mediated local forces into forming stable focal adhesions. A challenge remains in identifying and measuring these local cellular forces and in establishing empirical relationships between them, cell adhesion and filopodia formation.
View Article and Find Full Text PDFBiocompatible surfaces hold key to a variety of biomedical problems that are directly related to the competition between host-tissue cell integration and bacterial colonisation. A saving solution to this is seen in the ability of cells to uniquely respond to physical cues on such surfaces thus prompting the search for cell-instructive nanoscale patterns. Here we introduce a generic rationale engineered into biocompatible, titanium, substrates to differentiate cell responses.
View Article and Find Full Text PDFSequence-prescribed biomolecular assemblies find increasing use in the development of novel nanostructured materials. Critical requirements for emerging designs remain in matching form with function. Peptide assembly diversifies form and supports function, but lacks control over both.
View Article and Find Full Text PDFAn ability to construct biological matter from the molecule up holds promise for applications ranging from smart materials to integrated biophysical models for synthetic biology. Biomolecular self-assembly is an efficient strategy for biomaterial construction which can be programmed to support desired function. A challenge remains in replicating the strategy synthetically, that is at will, and differentially, that is for a specific function at a given length scale.
View Article and Find Full Text PDFTissue Eng Part C Methods
January 2013
The initial attachment of cells to biomaterials is an important indicator of longer term cell-substrate biocompatibility. To study and quantify this interaction, we have developed a protocol for measuring temporal changes in the three-dimensional (3D) morphology of mammalian cells seeded onto different substrates using fluorescence confocal laser scanning microscopy and image processing techniques. This method has been used to investigate how morphology parameters, such as cell thickness, volume, and the footprint area, change over time for osteosarcoma cells on uncoated glass control, fibronectin-coated glass, and titanium substrates.
View Article and Find Full Text PDFTwo ambient ionisation techniques, desorption electrospray ionisation (DESI) and plasma assisted desorption ionisation (PADI), have been used to analyse personal care products (PCPs) on fixed fibroblast cell surfaces. The similarities and differences between the two techniques for this type of analysis have been explored in various ways. Here, we show the results of DESI and PADI analysis of individual PCP ingredients as well as the analysis of these as complex creams on model skin surfaces, with minimal sample preparation.
View Article and Find Full Text PDFEncapsulation of living cells into gel-like matrices that are capable of maintaining their viability over an extended time period is starting to play a major role in medicine in applications such as, cell-based sensors, cellular therapy, and tissue engineering. The permeability of nutrients and waste products through these matrices is critical to their performance. In this article, we report a methodology for selecting scaffolds with different permeabilities and surface area/volume ratios that can be used to house a 3D cell aggregate.
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