Naing Tun Thet

University of Bath | UB · Department of Chemistry

Infection and blockage of indwelling urinary catheters is significant owing to its high incidence rate and severe medical consequences. Bacterial enzymes are employed as targets for small molecular intervention in human bacterial infections. Urease is a metalloenzyme known to play a crucial role in the pathogenesis and virulence of catheter-associa...

Biofilm formation in wounds is considered a major barrier to successful treatment, and has been associated with the transition of wounds to a chronic non-healing state. Here, we present a novel laboratory model of wound biofilm formation using ex-vivo porcine skin and a custom burn wound array device. The model supports high-throughput studies of b...

It is becoming increasingly accepted that to understand and model the bacterial colonization and infection of abiotic surfaces requires the use of a biofilm model. There are many bacterial colonizations by at least two primary species, however this is difficult to model in vitro. This study reports the development of a simple mixed‐species biofilm...

Formation of crystalline biofilms following infection by Proteus mirabilis can lead to encrustation and blockage of long-term indwelling catheters, with serious clinical consequences. We describe a simple sensor, placed within the catheter drainage bag, to alert of impending blockage via a urinary color change. The pH-responsive sensor is a dual-la...

We investigate the ability to disrupt and limit growth biofilms ol Pseudomonas aeruginosa using application of cold atmospheric pressure (CAP) plasma. The effect of the bio-film's exposure to a helium (CAP)jet was assessed at varying time points during biofilm matura­tion. Results showed that the amount of time during biofilm growth that CAP pressu...

We describe a novel infection-responsive coating for urinary catheters that provides a clear visual early warning of Proteus mirabilis infection and subsequent blockage. The crystalline biofilms of P. mirabilis can cause serious complications for patients undergoing long-term bladder catheterisation. Healthy urine is around pH 6, bacterial urease i...

Supplementary material

The early detection of wound infection in situ can dramatically improve patient care pathways and clinical outcomes. There is increasing evidence that within an infected wound the main bacterial mode of living is a biofilm: a confluent community of adherent bacteria encased in an extracellular polymeric matrix. Here we have reported the development...

This work presents an electrochemical sensor concept for bacterial toxin detection using biomimetic lipid vesicles containing potassium ferricyanide. The toxin mediated release of redox couples from the vesicles was quantified by measuring the redox current on screen printed electrodes, and the detection limits to rhamnolipid, delta toxin and bacte...

The use of hydrogels as safe, biocompatible materials for wound healing has been widely utilized in recent years. Here, we investigated the use of a composite hydrogel to impart a “trigger” mechanism into an antimicrobial hydrogel system. The system was comprised of a bilayer hydrogel architecture: a lower agarose layer containing the antimicrobial...

Liposomes containing lipids and polydiacetylene (PDA) are hybrid systems encompassing both a fluid phospholipid membrane and a polymer scaffold (PDA). However, the biophysical role of PDA in such liposomes is not well understood. In this report, we studied the effects of photo-polymerization of PDA on the stability of lipid-PDA liposomes, and their...

Phospholipid vesicles have been the focus of attention as potential vehicles for drug delivery, as they are biomimetic, easy to produce and contain an aqueous compartment which can be used to carry hydrophilic material, such as drugs or dyes. Lipid vesicles used for this purpose present a particular challenge, as they are not especially stable, and...

A synthetic biological sensor was developed to monitor the interaction of plasma with soft, hydrated biological material. It comprises phospholipid vesicles in a hydrated proteinaceous environment comprising 5% (w/v) gelatin. The vesicles contained a self-quenched dye, which was activated by vesicle destruction giving a clear fluorescent switch on....

A method for forming interconnects in a substrate, the substrate comprising a semiconductor layer on an oxide layer forming a silicon-on-oxide substrate, the method comprising forming a plurality of holes into the substrate to the semiconductor layer, and metalizing the plurality of holes to form the interconnects.

This paper describes a biosensing concept for exotoxins secreted by Staphylococcus aureus and Pseudomonas aeruginosa based on the toxin mediated breakdown and subsequent fluorescent dye release from phospholipid vesicles (liposomes). The sensitivity of vesicles to toxins was tuned by altering the lipid and fatty acid composition of the membranes su...

A new methodology for detecting the microbiological state of a wound dressing in terms of its colonization with pathogenic bacteria such as Staphylococcus aureus or Pseudomonas aeruginosa has been developed. Here we report how stabilized lipid vesicles containing self-quenched carboxyfluorescein dye are sensitive to lysis only by toxins/virulence f...

Pathogenic bacteria secrete various virulence factors, including toxins, lipases and proteases that allow them to infect, breakdown and colonize host tissue. Among various modes of action that the pathogenic bacteria use to damage the host, pore formation (by pore forming toxins (PFTs)) and lipid hydrolysis (by phospholipases) modes are common in d...

Pathogenic bacteria secrete various virulence factors that can directly interact with the outer lipid bilayer membrane of eukaryotic cells, inducing cell death by apoptosis or necrosis. Such virulence factors account for much of the toxic action associated with bacterial infection; therefore the detection of such proteins could provide a methodolog...

In a planar configuration, multiple electrical connections to a single molecule require an atomic scale precision of the wiring and an atomically flat supporting surface. Current nanofabrication techniques cannot achieve this on the same surface of a wafer. A double sided interconnection process flow adopted from sensor technology is presented usin...

We present for the first time TEM cross-section studies of Au nanowires fabricated with nanostencil membranes. Au metallic nanowires from 100 to 20?nm in width are fabricated on metallic, semiconducting and insulating substrates. The observed profiles require consideration of wetting for a satisfactory understanding. This length scale is easily acc...

Various types of pressure sensors are widely used in manufacturing, defence, medical and precision industries. Most of these sensors are based on either piezoelectric or piezoresistive mechanism for sensing applications. Piezoelectric pressure sensors are not suited for measuring static pressure mainly due to leakage of electric charges under const...