Development of a Novel Treatment Device for Upper Gastrointestinal Complications

One of the major upper gastrointestinal (UGI) complications that affect approximately 1 in 10 Australians is gastro-oesophageal reflux disease (GORD). GORD is when stomach acid frequently passes back up into the oesophagus and damages the oesophageal wall. Research has shown that frequent exposure of acid can increase the risk of adenocarcinoma in the oesophagus, where in Western populations the incidence is increasing. The survival rate for patients with oesophageal adenocarcinoma is low. This thesis proposed to develop a device with the potential to treat GORD and in turn reduce the risk of adenocarcinoma formation. The proposed device is made up of two main components, an anti-reflux valve and a novel device attachment system that uses LED light activation to adhere to tissue. Various tests were conducted such as tensile test, SEM imaging, pressure tests and cell cultures. These tests were performed to determine the device’s potential. The results showed that after 10 minutes of LED light activation the adhesive lap shear strength on porcine tissue was 7.50 kPa. The device showed it could support cell attachment and proliferation. Various valve designs were investigated, with the best valve able to prevent pressure up to 6 kPa, close to the natural pressure exerted by the lower oesophageal sphincter. Deployment of the device in porcine oesophagus using a standard medical endoscope was promising, but further optimisation is required. The significance of this research showed that a light activated adhesive system was possible using standard LED lighting, achieving strengths superior to fibrin glue while being safe and capable of tissue integration. The other key outcome was silicone anti-reflux valves were made from 3D-printed moulds capable of replicating the resistance of natural oesophagus. The final device shows promise and with future development could become a new treatment option for long-term sufferers of GORD. One of the major upper gastrointestinal (UGI) complications that affect approximately 1 in 10 Australians is gastro-oesophageal reflux disease (GORD). GORD is when stomach acid frequently passes back up into the oesophagus and damages the oesophageal wall. Research has shown that frequent exposure of acid can increase the risk of adenocarcinoma in the oesophagus, where in Western populations the incidence is increasing. The survival rate for patients with oesophageal adenocarcinoma is low. This thesis proposed to develop a device with the potential to treat GORD and in turn reduce the risk of adenocarcinoma formation. The proposed device is made up of two main components, an anti-reflux valve and a novel device attachment system that uses LED light activation to adhere to tissue. Various tests were conducted such as tensile test, SEM imaging, pressure tests and cell cultures. These tests were performed to determine the device’s potential. The results showed that after 10 minutes of LED light activation the adhesive lap shear strength on porcine tissue was 7.50 kPa. The device showed it could support cell attachment and proliferation. Various valve designs were investigated, with the best valve able to prevent pressure up to 6 kPa, close to the natural pressure exerted bOne of the major upper gastrointestinal (UGI) complications that affect approximately 1 in 10 Australians is gastro-oesophageal reflux disease (GORD). GORD is when stomach acid frequently passes back up into the oesophagus and damages the oesophageal wall. Research has shown that frequent exposure of acid can increase the risk of adenocarcinoma in the oesophagus, where in Western populations the incidence is increasing. The survival rate for patients with oesophageal adenocarcinoma is low. This thesis proposed to develop a device with the potential to treat GORD and in turn reduce the risk of adenocarcinoma formation. The proposed device is made up of two main components, an anti-reflux valve and a novel device attachment system that uses LED light activation to adhere to tissue. Various tests were conducted such as tensile test, SEM imaging, pressure tests and cell cultures. These tests were performed to determine the device’s potential. The results showed that after 10 minutes of LED light activation the adhesive lap shear strength on porcine tissue was 7.50 kPa. The device showed it could support cell attachment and proliferation. Various valve designs were investigated, with the best valve able to prevent pressure up to 6 kPa, close to the natural pressure exerted by the lower oesophageal sphincter. Deployment of the device in porcine oesophagus using a standard medical endoscope was promising, but further optimisation is required. The significance of this research showed that a light activated adhesive system was possible using standard LED lighting, achieving strengths superior to fibrin glue while being safe and capable of tissue integration. The other key outcome was silicone anti-reflux valves were made from 3D-printed moulds capable of replicating the resistance of natural oesophagus. The final device shows promise and with future development could become a new treatment option for long-term sufferers of GORD. y the lower oesophageal sphincter. Deployment of the device in porcine oesophagus using a standard medical endoscope was promising, but further optimisation is required. The significance of this research showed that a light activated adhesive system was possible using standard LED lighting, achieving strengths superior to fibrin glue while being safe and capable of tissue integration. The other key outcome was silicone anti-reflux valves were made from 3D-printed moulds capable of replicating the resistance of natural oesophagus. The final device shows promise and with future development could become a new treatment option for long-term sufferers of GORD

Review : photochemical tissue bonding (PTB) methods for sutureless tissue adhesion

Every year more and more medical devices are being implanted in the human body. Sutures are currently the gold standard for attachment of these devices, but they have associated issues such as needle trauma, unsuitability for certain tissues, such as eye or lung, and require skilled surgeons. A variety of sutureless methods have been developed to overcome some of these issues. Sutureless methods developed include fibrin glue, cyanoacrylates, scaffolds and bio-inspired adhesives. A sutureless method that is receiving increasing attention is Photochemical Tissue Bonding (PTB). This method involves using photoactive dyes and light-activation to initiate a chemical reaction that forms cross-links with collagen. In this review, we describe the current status of PTB. A variety of dyes have been identified and the literature analysed to identify the most promising photoactive dyes for PTB. Rose Bengal appears to be the most promising of the dyes identified as it produces the strongest bonding of all the dyes and its use is associated with minimal thermal damage. Development of applications for Rose Bengal is an area of active research with multiple articles published in the last 5 years. The outlook is promising for PTB and Rose Bengal to provide clinically viable solutions for tissue adhesion

Putting Social Science Applications on the Grid

As e-Social Science develops, there will be a growing user base of social researchers who are keen to share resources and applications in order to tackle some of the large-scale research challenges that confront us. They will be aware of the potential of e-Science technology to provide collaborative tools and provide access to distributed computing resources and data. However social scientists are not ideally catered for by the current Grid middleware and often lack the extensive programming skills to use the current infrastructure to the full and to adapt their existing “heritage ” applications. In late 2003, a lightweight client toolkit that is easily installable, yet provides extensible access mechanisms to Grid resources was seen as a possible solution. By implementing a client-side polling strategy, problems associated with institutional firewalls for Grid protocols can be reduced. This is an alternative strategy to a Grid portal, easing the access problems while still sharing the same underlying services and infrastructure. A prototype library called GROWL: Grid Resources on Workstation Library was developed to use a client-server model to interface to existing Grid Services from applications written in C, C++, Fortran and R. Together with its associated wrapper services, GROWL is now being further developed into a number of demonstrators as part of the JISC-funded Virtual Research Environment (VRE) Programme by a collaboration from CCLRC Daresbury Laboratory an

Characterisation of a novel light activated adhesive scaffold : potential for device attachment

The most common methods for attaching a device to the internal tissues of the human body are via sutures, clips or staples. These attachment techniques require penetration and manipulation of the tissue. Tears and leaks can often be a complication post-attachment, and scarring usually occurs around the attachment sites. To resolve these issues, it is proposed to develop a soft tissue scaffold impregnated with Rose Bengal/Chitosan solution (RBC-scaffold, 0.01% w/v Rose Bengal, 1.7% w/v Medium Molecular Weight Chitosan). This scaffold will initially attach to the tissue via a light activation method. The light activates the dye in the scaffold which causes cross-links to form between the scaffold and tissue, thus adhering them together. This is done without mechanically manipulating the surrounding tissue, thus avoiding the issues associated with current techniques. Eventually, the scaffold will be resorbed and tissue will integrate for long-term attachment. A variety of tests were performed to characterise the RBC-scaffold. Porosity, interconnectivity, and mechanical strength were measured. Light activation was performed with a broad spectrum (380-780 nm) 10 W LED lamp exposed to various time lengths (2-15 min, Fluence range 0.4-3 J/cm2 ). Adhesive strength of the light-activated bond was measured with lap-shear tests performed on porcine stomach tissue. Cell culture viability was also assessed to confirm tissue integration potential. These properties were compared to Variotis™, an aliphatic polyester soft tissue scaffold which has proven to be viable for soft tissue regeneration. The RBC-scaffolds were found to have high porosity (86.46±2.95%) and connectivity, showing rapid fluid movement. The elastic modulus of the RBC-scaffolds (3.55±1.28 MPa) was found to be significantly higher than the controls (0.15±0.058 MPa, p0.01) and approached reported values for human gastrointestinal tissue (2.3 MPa). The maximum adhesion strength achieved of the RBC-scaffolds was 8.61±2.81 kPa after 15 min of light activation, this is comparable to the adhesion strength of fibrin glue on scaffolds. Cell attachment was seen to be similar to the controls, but cells appeared to have better cell survivability. In conclusion, the RBC-scaffolds show promise for use as a novel light activated attachment device with potential applications in attaching an anti-reflux valve in the lower oesophagus and also in wound healing applications for stomach ulcers