Development of a cell sensing and electrotherapeutic system for a smart stent

Cardiovascular diseases (CVD) is one of the main causes of death worldwide. Coronary heart disease (CHD) and strokes are the highest contributors to CVD deaths (46 % and 26 % respectively) in the UK. The condition which leads to CHD is Coronary artery disease (CAD). The main cause of CAD is coronary atherosclerosis, which involves an inflammatory response of the artery wall to chronic multifactorial injury, which then results into formation of atherosclerotic plaques. One of the main treatment strategies for CAD is Percutaneous Coronary Intervention (PCI). PCI is a procedure during which a balloon mounted catheter with an unexpanded stent is inserted into a peripheral artery and threaded up to the site of stenosis in the coronary artery of the heart to reopen the vessel. PCI usually involves stenting with a Bare Metal Stent (BMS) or Drug Eluting Stent (DES). The 9-month revascularisation rate is 12.32 % with BMS, and this rate has significantly decreased to 4.34 % with early generation DES. The latest generation of DES is associated with revascularisation rates of 2.91 %. Detection of this vascular hyperplasia is a common limitation of these devices which can be found across a number of vascular pathologies. In this project, we developed a new type of biosensor for detecting the changes associated with these blockages that could be mounted on these implantable medical devices. Our design and development led to a comprehensive characterisation of both the sensor and its cell interactions. Proof of concept experiments were performed that legitimised the concept of a smart self-reporting device, as a solution to remote detection of In-stent Restenosis (ISR). The proposed smart stent would have both diagnostic and therapeutic capabilities. Preliminary tests showed that the devices were minimally susceptible to changes in volume and conductivity of culture medium, during baseline measurements. Sensors of different dimensions were fabricated with the best version 16 times smaller but with 4.35 times higher sensitivity in cell detection compared to baseline. Our sensor could also distinguish between different cell types. Indeed the sensor coverage could be remotely monitored intermittently (at 24 h intervals) or continuously (at 15 min intervals) or on demand. Continuous monitoring allowed the gradual changes in cell phenotype to be monitored including cell adherence, proliferation and death which was then correlated with live cell sensor imaging. We found our sensors could be used for both cell detection and therapeutic intervention. As the fabricated biosensors are intended to be integrated onto a future smart stent, this would be implanted in vivo and would be subjected to blood flow. Therefore it was important to test the devices under flow conditions. Our data show that, when incorporated into microfluidic flow chambers, the sensors could exquisitely detect cell adherence under flow and static conditions. Moreover they were also suitable for monitoring the gradual migration and proliferation of vascular cells within a microfluidic channel. Future development of these proof-of-concept biosensors is critical for future commercialisation of this important novel device, which hopefully will provide a new class of diagnostic and therapeutic vascular devices

Characterising vascular cell monolayers using electrochemical impedance spectroscopy and a novel electroanalytical plot

The Editor-in-chief and Publisher of Nanotechnology, Science and Applications wish to retract the published paper. We were notified by the University of Glasgow’s Research Integrity Council that an investigation had found the scientific integrity of the paper had been compromised and it needed to be retracted. The investigation found the author had published data belonging to a group collaboration effort without proper authorisation, which included the use of the image shown in Figure 2. The author had published the paper under a grant he was not entitled to access and by publishing certain details within the paper the author had breached the University of Glasgow’s Intellectual Property polices. The Editor has agreed with the request to retract the paper. Our decision-making was informed by our policy on publishing ethics and integrity and the COPE guidelines on retraction. The retracted article will remain online to maintain the scholarly record, but it will be digitally watermarked on each page as “Retracted”

Future of smart cardiovascular implants

Cardiovascular disease remains the leading cause of death in Western society. Recent technological advances have opened the opportunity of developing new and innovative smart stent devices that have advanced electrical properties that can improve diagnosis and even treatment of previously intractable conditions, such as central line access failure, atherosclerosis and reporting on vascular grafts for renal dialysis. Here we review the latest advances in the field of cardiovascular medical implants, providing a broad overview of the application of their use in the context of cardiovascular disease rather than an in-depth analysis of the current state of the art. We cover their powering, communication and the challenges faced in their fabrication. We focus specifically on those devices required to maintain vascular access such as ones used to treat arterial disease, a major source of heart attacks and strokes. We look forward to advances in these technologies in the future and their implementation to improve the human condition

Real-time monitoring of oxygen levels within thermoplastic Organ-on-Chip devices

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