David Alexander Gregory

David Alexander Gregory
The University of Sheffield | Sheffield · Department of Materials Science and Engineering

PhD; MSc; BSc; BSc; FHEA

About

26
Publications
3,294
Reads
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543
Citations
Additional affiliations
October 2013 - July 2015
The University of Sheffield
Position
  • Lab Teaching Undergraduate Students
Description
  • Teaching Undergraduate students in Experimental Labs
Education
September 2010 - September 2011
The University of Sheffield
Field of study
  • Bionanotechnology
September 2007 - July 2010
Keele University
Field of study
  • Biochemistry and Music Dual Hons.
October 2004 - July 2007
Lancaster University
Field of study
  • Physics with Astrophysics and Cosmology

Publications

Publications (26)
Article
Spherical colloids decorated with a surface coating of catalytically active material are capable of producing autonomous motion in fluids by decomposing dissolved fuel molecules to generate a gaseous product, resulting in momentum generation by bubble growth and release. Such colloids are attractive as they are relatively simple to manufacture comp...
Article
Full-text available
Inkjet-printed enzyme-powered silk-based micro-rockets are able to undergo autonomous motion in a vast variety of fluidic environments including complex media such as human serum. By means of digital inkjet printing it is possible to alter the catalyst distribution simply and generate varying trajectory behavior of these micro-rockets. Made of silk...
Article
While much attention has focused on self-motile asymmetrical catalytically active “Janus” colloids as a route to enable new fluidic transport applications, the motion of symmetrical catalytically active colloids is less well investigated. This is despite isotopically active colloids being more accessible, and commonly used as supports for heterogen...
Article
Full-text available
Ulceration of the oral mucosa is common, can arise at any age and as a consequence of the pain lessens enjoyment and quality of life. Current treatment options often involve the use of topical corticosteroids with poor drug delivery systems and inadequate contact time. In order to achieve local controlled delivery to the lesion with optimal adhesio...
Article
Natural biomaterials have benefited the human civilisation for millennia. However, in recent years, designing of natural materials for a wide range of applications have become a focus of attention, spearheaded by sustainability. With advances in materials science, new ways of manufacturing, processing, and functionalising biomaterials for structura...
Article
Polyhydroxyalkanoates (PHAs) are sustainable, versatile, biocompatible, and bioresorbable polymers that are suitable for biomedical applications. Produced via bacterial fermentation under nutrient-limiting conditions, they are uncovering a new horizon for devices in biomedical applications. A wide range of cell types including bone, cartilage, nerv...
Article
Hypothesis Water contamination is a serious global challenge and an on-site and out-of-lab method of assessment of contamination level is highly needed. In this study, we report the potential of using printable and biodegradable propelling sensors as indicators of water contamination in sewage wastewater. Experiments We used reactive 3D inkjet pri...
Article
Full-text available
The ability to generate rotation in ellipsoidal catalytic micro swimming devices by catalyst deposition at glancing angles allows reliable access to circling trajectories. This behaviour could enable propulsive ellipsoids to gather cargo and enhance mixing at small scales. Catalytically propelled colloidal rotation has been previously achieved in s...
Article
Full-text available
Guiding neuronal cell growth is desirable for neural tissue engineering but is very challenging. In this work, a self-assembling ultra-short surfactant-like peptide I3K which possesses positively charged lysine head groups, and hydrophobic isoleucine tails, was chosen to investigate its potential for guiding neuronal cell growth. The peptides were...
Article
Full-text available
Tissue engineering (TE) is the approach to combine cells with scaffold materials and appropriate growth factors to regenerate or replace damaged or degenerated tissue or organs. The scaffold material as a template for tissue formation plays the most important role in TE. Among scaffold materials, silk fibroin (SF), a natural protein with outstandin...
Article
Full-text available
The patterning of neuronal cells and guiding neurite growth are important for neuron tissue engineering and cell-based biosensors. In this paper, inkjet printing has been employed to pattern self-assembled I3QGK peptide nanofibers on silk substrates for guiding the growth of neuron-like PC12 cells. Atomic force microscopy (AFM) confirmed the dynami...
Article
Full-text available
Cardiovascular diseases (CVD) constitute a major fraction of the current major global diseases and lead to about 30% of the deaths, i.e., 17.9 million deaths per year. CVD include coronary artery disease (CAD), myocardial infarction (MI), arrhythmias, heart failure, heart valve diseases, congenital heart disease, and cardiomyopathy. Cardiac Tissue...
Article
Full-text available
In this study, a protocol for using reactive inkjet printing to fabricate enzymatically propelled silk swimmers with well-defined shapes is reported. The resulting devices are an example of self-propelled objects capable of generating motion without external actuation and have potential applications in medicine and environmental sciences for a vari...
Article
Full-text available
Curcumin is a promising anti-cancer drug, but its applications in cancer therapy are limited, due to its poor solubility, short half-life and low bioavailability. In this study, curcumin loaded magnetic alginate/chitosan nanoparticles were fabricated to improve the bioavailability, uptake efficiency and cytotoxicity of curcumin to Human Caucasian B...
Article
Full-text available
The lack of efficient and cost-effective methods for gene delivery has significantly hindered the applications of gene therapy. In this paper, a simple one step and cost effective salting-out method has been explored to fabricate silk-PEI nanoparticles (SPPs) and magnetic-silk/PEI core-shell nanoparticles (MSPPs) for targeted delivery of c-myc anti...
Preprint
Curcumin is a promising anti-cancer drug but its applications in cancer therapy are limited due to its poor solubility, short half-life and low bioavailability. In this study, curcumin loaded magnetic alginate / chitosan nanoparticles were fabricated to improve the bioavailability, uptake efficiency and cytotoxicity of curcumin to MDA-MB-231 breast...
Article
Catalytic Janus colloids produce rapid motion in fluids by decomposing dissolved fuel. There is great potential to exploit these “autonomous chemical swimmers” in applications currently performed by diffusion limited passive colloids. Key application areas for colloids include transporting active ingredients for drug delivery, gathering analytes fo...
Chapter
This chapter describes how small-scale devices with a “two-faced” structure, often termed catalytic Janus swimmers, can be used to generate autonomous motion within fluids at small scales. The chapter starts by giving a general introduction to the field of swimming devices, and then surveys the variety of different Janus structures that have been u...
Conference Paper
Full-text available
Regenerated silk fibroin (RSF) protein is an FDA approved biomaterial and has been used as a bio-ink to structures using inkjet printing. Silk can be present in water soluble amorphous (Silk I) and water insoluble fabricate crystalline conformations (Silk II) made up of beta-sheet structures. Here we show the generation of silk scaffolds by inkjet...
Article
On page 4048, X. Zhao, S. J. Ebbens, and co-workers demonstrate the ability to fabricate biocompatible silk microrockets via reactive inkjet printing. The microrockets are powered by catalase and undergo bubble propulsion in the presence of hydrogen peroxide. Microrockets are capable of swimming in a large variety of media including biological solu...
Article
Full-text available
The effect of added salt on the propulsion of Janus platinum-polystyrene colloids in hydrogen peroxide solution is studied experimentally. It is found that micromolar quantities of potassium and silver nitrate salts reduce the swimming velocity by similar amounts, while leading to significantly different effects on the overall rate of catalytic bre...

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