Potential of Microneedles in Enhancing Delivery of Photosensitising Agents for Photodynamic Therapy

Photodynamic therapy can be used in the treatment of pre-malignant and malignant diseases. It offers advantages over other therapies currently used in the treatment of skin lesions including avoidance of damage to surrounding tissue and minimal or no scarring. Unfortunately, systemic delivery of photosensitising agents can result in adverse effects, such as prolonged cutaneous photosensitivity; while topical administration lacks efficacy in the clearance of deeper skin lesions and those with a thick overlying keratotic layer. Therefore, enhancement of conventional photosensitiser delivery is desired. However, the physicochemical properties of photosensitising agents, such as extreme hydrophilicity or lipophilicity and large molecular weights make this challenging. This paper reviews the potential of microneedles as a viable method to overcome these delivery-limiting physicochemical characteristics and discusses the current benefits and limitations of solid, dissolving and hydrogel-forming microneedles. Clinical studies in which microneedles have successfully improved photodynamic therapy are also discussed, along with benefits which microneedles offer, such as precise photosensitiser localisation, painless application and reduction in waiting times between photosensitiser administration and irradiation highlighted.

Synergistic effects on gene delivery - co-formulation of small disulfide-linked dendritic polycations with Lipofectamine 2000 (TM)

This paper describes the application of gene delivery vectors based on connecting together two well-defined low-generation poly(L-lysine) (PLL) dendrons using a disulfide-containing linker unit. We report that the transfection ability of these vectors in their own right is relatively low, because the low-generation number limits the endosomal buffering capacity. Importantly, however, we demonstrate that when applied in combination with Lipofectamine 2000 (TM), a vector from the cationic lipid family, these small cationic additives significantly enhance the levels of gene delivery (up to four-fold). Notably, the cationic additives have no effect on the levels of transfection observed with a cationic polymer, such as DEAE dextran. We therefore argue that the synergistic effects observed with Lipofectamine 2000 (TM) arise as a result of combining the delivery advantages of two different classes of vector within a single formulation, with our dendritic additives providing a degree of pH buffering within the endosome. As such, the data we present indicate that small dendritic structures, although previously largely overlooked for gene delivery owing to their inability to transfect in their own right, may actually be useful well-defined additives to well-established vector systems in order to enhance the gene delivery payload.

Serving Multiple Masters: Exploring HRD in the Context of Third Sector Partnerships for Public Service Delivery

Organisations in the Non-Profit and Voluntary (NPV) sector increasingly face challenging and uncertain times with an increasing shift from public grant funding towards contract funding. As a result many of these changes employees in such organisations have often found themselves working more closely under contract with colleagues in public sector organisations in order to provide public services. Using a multiple case study methodology and in-depth interviewing of a range of stakeholders form two large Northern Irish based Non Profit Organisations in the social care sector, the purpose of this research was to
investigate HRD and people management issues and how a turbulent environment can affect how organisations approach HRD strategy and implementation.

The research identifies the importance placed upon NPOs adopting HRD strategies and addressing the development of unique and specialised skills in order to claw back power within the relationships they serve with statutory funding bodies. However this research also notes that the manner in which HRD and its associated issues are considered within NPOs can have an impact on the loyalty and commitment of the workforce which serves them. What is of concern is that the context for the delivery of public services under contract is putting increasing strain on NPOs and this has been felt markedly by their respective workforces, and unless strong values-led leadership and managerial practice is in
place in NPOs, the voluntary-centred ethos of those who work in the sector may be significantly damaged.

Supporting delivery of the recovery package for people living with and beyond cancer

Survivorship is an important issue in cancer care in the UK. More people are being diagnosed with the disease and many more are living for longer after diagnosis. The National Cancer Survivorship Initiative recommends that patients with cancer have a package of care designed to improve outcomes and support for those living with and beyond the disease. The recovery package consists of a holistic needs assessment, treatment summary, cancer care review and health and wellbeing event. Although these interventions are recommended as a way to improve care, many people do not have access to the combined package, or even some of its components. The Cancer Nursing Partnership (CNP), a collaboration of cancer nursing organisations and communities of influence, has been established to support nurses with delivery of the recovery package in practice. This article describes the package and its components, introduces the CNP and outlines the work it has carried out to date.

Hydrogel-Forming Microneedles Prepared from ‘‘Super Swelling’’ Polymers Combined with Lyophilised Wafers for Transdermal Drug Delivery

We describe, for the first time, hydrogel-forming microneedle arrays prepared from "super swelling" polymeric compositions. We produced a microneedle formulation with enhanced swelling capabilities from aqueous blends containing 20% w/w Gantrez S-97, 7.5% w/w PEG 10,000 and 3% w/w Na2CO3 and utilised a drug reservoir of a lyophilised wafer-like design. These microneedle-lyophilised wafer compositions were robust and effectively penetrated skin, swelling extensively, but being removed intact. In in vitro delivery experiments across excised neonatal porcine skin, approximately 44 mg of the model high dose small molecule drug ibuprofen sodium was delivered in 24 h, equating to 37% of the loading in the lyophilised reservoir. The super swelling microneedles delivered approximately 1.24 mg of the model protein ovalbumin over 24 h, equivalent to a delivery efficiency of approximately 49%. The integrated microneedle-lyophilised wafer delivery system produced a progressive increase in plasma concentrations of ibuprofen sodium in rats over 6 h, with a maximal concentration of approximately 179 µg/ml achieved in this time. The plasma concentration had fallen to 71±6.7 µg/ml by 24 h. Ovalbumin levels peaked in rat plasma after only 1 hour at 42.36±17.01 ng/ml. Ovalbumin plasma levels then remained almost constant up to 6 h, dropping somewhat at 24 h, when 23.61±4.84 ng/ml was detected. This work represents a significant advancement on conventional microneedle systems, which are presently only suitable for bolus delivery of very potent drugs and vaccines. Once fully developed, such technology may greatly expand the range of drugs that can be delivered transdermally, to the benefit of patients and industry. Accordingly, we are currently progressing towards clinical evaluations with a range of candidate molecules.

Evaluation of Multidisciplinary Delivery of Surgical Anatomy Teaching

Title Evaluation of Multidisciplinary Delivery of Surgical Anatomy Teaching

Authors Walsh I.K., Taylor S.J., Dorman A, Boohan M.

Objectives To evaluate the efficacy of newly introduced multidisciplinary methods to deliver Surgical Anatomy teaching to undergraduate medical students.

Design and Setting Qualitative and quantitative study using questionnaires and focus groups, employing students of the perioperative and emergency medicine (POEM) module of the phase 4 undergraduate medical curriculum at Queen’s University Belfast.

Outcome Measures To determine:
(1) if multidisciplinary teaching is effective in delivering surgical anatomy teaching,
(2) student’s learning preferences regarding this teaching method.
Results The questionnaire response rate was 89% (216 of 244 students; female: male ratio 1.25) and 42 students participated in 6 focus groups. Mean questionnaire responses indicated a favourable opinion on quality assurance items and multidisciplinary teaching. 81% of students agreed that multidisciplinary teaching enhanced learning and 86% felt that this did not adversely affect interaction. A positive contribution towards POEM learning was reported for Radiology (95% of students), Anatomy (93%) and Surgery (78%). The benefits of multidisciplinary teaching were congruent for Anatomy, Radiology and Surgery with 78% of students indicating a perceived favourable association with learning. Multidisciplinary teaching was not associated with diluted interaction, with 62% of students describing interaction as sufficient. 88% of students positively ranked tutor characteristics of enthusiasm and encouragement as being strongly associated with teacher quality. Positive perception of overall quality was strongly associated with learning preferences as well as more generic quality assurance issues (80% students; alpha coefficient 0.83).
The results were supported by triangulation of the above quantitative data with qualitative data generated by the focus groups. Whilst students frequently misunderstood the meaning of “multidisciplinary teaching”, there was an appreciation of the method’s worth; students recognised and valued the relevance of Anatomy, Radiology and Surgery teaching to POEM learning. The importance of vertically integrating Anatomy into all stages of the undergraduate curriculum was especially recognised.

Reference Aarnio M, Nieminen J, Pyorala E, Lindbolm-Ylanne S. Motivating medical students to learn. 2010 Med Teach;32(4):199-204.