Oral Health Status of Patients Undergoing Treatment for Head and Neck Oncology in Northern Ireland

This study aimed to collect data on the oral health status of patients undergoing treatment for head and neck oncology across Northern Ireland. Data were collected on all patients referred to the Northern Ireland Multidisciplinary Head and Neck Oncology Team for discussion and treatment planning. Each patient underwent pre-treatment dental assessment in the Centre for Dentistry, Queen’s University Belfast, between June 2013 and November 2014. Data were collected from clinical oral examinations supplemented with intra-oral radiographs. During the course of the study 96 patients were assessed and the levels of dental disease observed in this cohort were high. On clinical examination
43% were diagnosed with caries and 46% with periodontal disease. Ten patients were completely edentate. The disease profile of this patient group presents significant challenges to dental services tasked with rendering patients dentally fit prior to undergoing oncology treatment.

POU2F1 activity regulates HOXD10 and HOXD11 promoting a proliferative and invasive phenotype in head and neck cancer

HOX genes are master regulators of organ morphogenesis and cell differentiation during embryonic development, and continue to be expressed throughout post-natal life. To test the hypothesis that HOX genes are dysregulated in head and neck squamous cell carcinoma (HNSCC) we defined their expression profile, and investigated the function, transcriptional regulation and clinical relevance of a subset of highly expressed HOXD genes. Two HOXD genes, D10 and D11, showed strikingly high levels in HNSCC cell lines, patient tumor samples and publicly available datasets. Knockdown of HOXD10 in HNSCC cells caused decreased proliferation and invasion, whereas knockdown of HOXD11 reduced only invasion. POU2F1 consensus sequences were identified in the 5' DNA of HOXD10 and D11. Knockdown of POU2F1 significantly reduced expression of HOXD10 and D11 and inhibited HNSCC proliferation. Luciferase reporter constructs of the HOXD10 and D11 promoters confirmed that POU2F1 consensus binding sites are required for optimal promoter activity. Utilizing patient tumor samples a significant association was found between immunohistochemical staining of HOXD10 and both the overall and the disease-specific survival, adding further support that HOXD10 is dysregulated in head and neck cancer. Additional studies are now warranted to fully evaluate HOXD10 as a prognostic tool in head and neck cancers.

Specialty Registrars’ Experience of Managing Head and Neck Cancer Patients

Objective The aim of this study was to collate and compare data on the training of Specialty Registrars in Restorative Dentistry (StRs) in the management of head and neck cancer (HANC) patients across different training units within the UK and Ireland. Methods Current trainees were invited to complete an online questionnaire by the Specialty Registrars in Restorative Dentistry Group (SRRDG). Participants were asked to rate their confidence and experience of assessing and planning treatment for HANC patients, attending theatre alone and manufacturing surgical obturators, and providing implants for appropriate cases. Respondents were also asked to appraise clinical and didactic teaching at their unit, and to rate their confidence of passing a future Intercollegiate Specialty Fellowship Examination (ISFE)-station assessing knowledge of head and neck cancer. Results Responses were obtained from 21 StRs (n=21) training within all five countries of the British Isles. Most respondents were based in England (76%), with one StR in each of Scotland, Wales, Northern Ireland and the Republic of Ireland. A third (33%) were in their 5th year of training. Almost half of the StRs indicated that they were confident of independently assessing (48%) new patients with HANC, with fewer numbers reporting confidence in treatment planning (38%). The majority (52%) of respondents indicated that they were not confident of attending theatre alone and manufacturing a surgical obturator. A third (33%) rated their experience of treating HANC patients with implants as ‘poor’ or ‘very poor’, including three StRs in their 5th year of training. Less than one third (<33%) rated didactic teaching in maxillofacial prosthodontics at their unit as ‘good’ or ‘excellent’, and only 7 StRs indicated that they were confident of passing an ISFE-station focused on HANC. Conclusion Experience and training regarding patients with head and neck cancer is inconsistent for StRs across the UK and Ireland with a number of trainees reporting a lack of clinical exposure.

Fibre laser joining of highly dissimilar materials: Commercially pure Ti and PET hybrid joint for medical device applications

Laser transmission joining (LTJ) is growing in importance, and has the potential to become a niche technique for the fabrication of hybrid plastic-metal joints for medical device applications. The possibility of directly joining plastics to metals by LTJ has been demonstrated by a number of recent studies. However, a reliable and quantitative method for defining the contact area between the plastic and metal, facilitating calculation of the mechanical shear stress of the hybrid joints, is still lacking. A new method, based on image analysis using ImageJ, is proposed here to quantify the contact area at the joint interface. The effect of discolouration on the mechanical performance of the hybrid joints is also reported for the first time. Biocompatible polyethylene terephthalate (PET) and commercially pure titanium (Ti) were selected as materials for laser joining using a 200 W CW fibre laser system. The effect of laser power, scanning speed and stand-off distance between the nozzle tip and top surface of the plastic were studied and analysed by Taguchi L9 orthogonal array and ANOVA respectively. The surface morphology, structure and elemental composition on the PET and Ti surfaces after shearing/peeling apart were characterized by SEM, EDX, XRD and XPS.

Transcending epithelial and intracellular biological barriers; a prototype DNA delivery device

Microneedle technology provides the opportunity for the delivery of DNA therapeutics by a non-invasive, patient acceptable route. To deliver DNA successfully requires consideration of both extra and intracellular biological barriers. In this study we present a novel two tier platform; i) a peptide delivery system, termed RALA, that is able to wrap the DNA into nanoparticles, protect the DNA from degradation, enter cells, disrupt endosomes and deliver the DNA to the nucleus of cells ii) a microneedle (MN) patch that will house the nanoparticles within the polymer matrix, breach the skin's stratum corneum barrier and dissolve upon contact with skin interstitial fluid thus releasing the nanoparticles into the skin. Our data demonstrates that the RALA is essential for preventing DNA degradation within the poly(vinylpyrrolidone) (PVP) polymer matrix. In fact the RALA/DNA nanoparticles (NPs) retained functionality when in the MN arrays after 28days and over a range of temperatures. Furthermore the physical strength and structure of the MNs was not compromised when loaded with the NPs. Finally we demonstrated the effectiveness of our MN-NP platform in vitro and in vivo, with systemic gene expression in highly vascularised regions. Taken together this 'smart-system' technology could be applied to a wide range of genetic therapies.

Laser-fabricated PET-Ti Hybrid Joints for Medical Device Applications

Currently, micro-joining of plastic parts to metal parts in medical devices is achieved by using medical adhesives, For example, pacemakers, defibrillators and neurological stimulators are designed using silicone adhesive to seal the joint between the polyurethane connector module and the titanium can [1]. Nevertheless, the use of adhesive is problematic because it requires a long time to cure and has high tendency to produce leachable products which might be harmful to the human body. An alternative for directly joining plastics to metal without adhesive is therefore required. Laser transmission joining (LTJ) is growing in importance, and has the potential to gain the niche in micro-fabrication of plastics-metal hybrid joints for medical device applications. The possibility of directly joining plastics to metal by LTJ technique have been demonstrated by a number of studies in recent literature [2]. The widely-accepted understanding of LTJ between plastics and metal is that generation and rapid expansion of micro-bubbles at the plastics-metal interface exert high local pressure to press the melted plastics towards the metal surface features during the laser processing [2]. This subsequently creates the plastics-metal hybrid joint by the mechanisms of mechanical interlocking as well as chemical and physical bonds between the plastics and metal surfaces. Although the micro-bubbles can help promote the mechanical interlocking effect to increase the joint strength, the creation of bubble is a random and complex process depending on the complicated interactions between the laser intensity, thermal degradation properties of plastics, surface temperature and topographical features of metal. In an ideal situation, it is desirable to create the hybrid plastics-metal joint without bubbles. However, the mechanical performance of the hybrid plastics-metal joint without bubbles is still unknown, and systematic comparison between the hybrid joints with and without bubbles is lacking in literature. This becomes the objective of this study. In this work, the laser process parameters were carefully chosen from a preliminary study, such that different hybrid joints: with and without bubbles can be produced and compared. Biocompatible PET and commercially pure Ti were selected as materials for laser joining.