Deploying clinical grade magnetic nanoparticles with magnetic fields to magnetolabel neural stem cells in adherent versus suspension cultures

Neural stem cells (NSCs) have a high therapeutic potential for patients with neurological disease/injury given their neuroregenerative and immunomodulatory capabilities. In recent years, magnetic nanoparticles (MNPs) have been used as contrast agents in translational studies, to track transplanted NSCs using non-invasive magnetic resonance imaging (MRI). However, NSC uptake of MNPs is inherently low in the absence of chemical/biological uptake enhancing strategies such as cell targeting peptides and transfection agents – approaches which may be cytotoxic and alter cellular physiology. By contrast, physical delivery strategies relying on magnetic assistive methods can safely enhance MNP uptake into multiple neural cell types. The utility of this approach has been demonstrated for gene delivery grade particles but their application in enhancing ‘magnetolabelling’ with clinical grade contrast agents has never been evaluated. Here, we show that applied oscillating magnetic fields can safely enhance the uptake of a clinical grade MNP (Lumirem/Ferumoxsil) into NSCs propagated as neurospheres (suspension cultures, the preferred format for transplantation) but offer limited benefit for monolayer (adherent) cultures. This physical delivery method therefore has potential to facilitate cell labelling for clinical therapies

Multiple exon skipping strategies to by-pass dystrophin mutations.

Manipulation of dystrophin pre-mRNA processing offers the potential to overcome mutations in the dystrophin gene that would otherwise lead to Duchenne muscular dystrophy. Dystrophin mutations will require the removal of one or more exons to restore the reading frame and in some cases, multiple exon skipping strategies exist to restore dystrophin expression. However, for some small intra-exonic mutations, a third strategy, not applicable to whole exon deletions, may be possible. The removal of only one frame-shifting exon flanking the mutation-carrying exon may restore the reading frame and allow synthesis of a functional dystrophin isoform, providing that no premature termination codons are encountered. For these mutations, the removal of only one exon offers a simpler, cheaper and more feasible alternative approach to the dual exon skipping that would otherwise be considered. We present strategies to by-pass intra-exonic dystrophin mutations that clearly demonstrate the importance of tailoring exon skipping strategies to specific patient mutations

Evaluation of a manualised speech and language therapy programme for children with social communication disorder: the SCIP feasibility study

Background: Children with Social (Pragmatic) Communication Disorder (SPCD) have long-3 term needs in using and processing social language and have a high risk of later mental health difficulties. A manualised speech and language therapy programme, the Social Communication Intervention Programme (SCIP) provides therapy content for SPCD. A feasibility study is required to derive more precise estimates of key parameters for a future trial of SCIP. Aims: To assess the feasibility of conducting a substantive randomized controlled trial of SCIP for children with SPCD. Methods: A questionnaire was distributed to paediatric speech and language therapists in England. Survey questions addressed number of eligible children, routine intervention provision and trial recruitment factors. In the second phase, a single-arm intervention feasibility study was completed. 15 speech and language practitioners identified 24 children aged 5-11 years with SPCD. Practitioners received training/supervision to deliver 20 SCIP therapy sessions to each child. At Time 1 parents of participating children provided three communication goals; expected steps in each goal were defined. After intervention, parents and practitioners independently rated each goal compared to baseline ability. Two research practitioners compared parent post-intervention commentaries with outcome scores to derive guidance about clinical significance. All practitioners recorded audio commentaries on therapy experiences. Post-intervention interviews were conducted with 6 practitioners and 6 parents. An expert panel completed a Delphi consultation on trial design. Results: Routine practice for SPCD varies widely. Children tend to be embedded in autism provision. Participation in a future trial was well-supported, provided resources are available to services. Outcomes analysis indicated all children except one made some progress on parent ratings; all children made progress on practitioner ratings. A power analysis for a future trial was carried out using current outcome measure as putative primary endpoint. Practitioners’ audio-diaries provided suggestions for training and adaption in a future trial. Outcomes and therapy methods were acceptable to practitioners and parents. Conclusions: The feasibility study evaluated a novel outcome measure of social communication skills in SPCD. A power calculation indicated a feasible framework for a trial within a realistic period of time. Recommendations for recruitment methods, adaptation of manual and training were 6 supported by practitioners and an expert panel

Developing A New Strategy for Delivery of Neural Transplant Populations using Precursor Cell Sprays and Specialised Cell Media

Neural precursor/stem cell transplantation therapies promote regeneration in neurological injuries, but current cell delivery methods have drawbacks. These include risks with surgical microinjection (e.g., hemorrhage, embolism) and high cell loss with systemic delivery/passage through fine gauge needles. Aerosolized cell delivery offers significant benefits including rapid and minimally invasive cell delivery, and ease of delivery to end users. To develop this approach, it is necessary to prove that 1) aerosolization does not have detrimental effects on transplant cells and 2) suitable media can be identified to support cell delivery. To achieve these aims, cells are sprayed using a commercial spray device or stored in Hibernate-A, a CO2-independent nutrient solution. Histological assessments consist of cell viability analysis, immunocytochemistry, and EdU labeling. It is shown that a major neural precursor transplant population-oligodendrocyte precursor cells (OPCs)-survive following aerosolized delivery and retain their capacity for proliferation and differentiation (key to their repair function). Hibernate-A can support OPCs' survival without specialized maintenance conditions, with no detrimental impact on cell fate. It is considered that this data supports the concept of a novel class of advanced medical spray devices to facilitate transport and delivery of transplant populations in neural cell therapy

Developing human dish models of neurological pathology

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Poloxomer 188 Has a Deleterious Effect on Dystrophic Skeletal Muscle Function

Duchenne muscular dystrophy (DMD) is an X-linked, fatal muscle wasting disease for which there is currently no cure and limited palliative treatments. Poloxomer 188 (P188) is a tri-block copolymer that has been proposed as a potential treatment for cardiomyopathy in DMD patients. Despite the reported beneficial effects of P188 on dystrophic cardiac muscle function, the effects of P188 on dystrophic skeletal muscle function are relatively unknown. Mdx mice were injected intraperitoneally with 460 mg/kg or 30 mg/kg P188 dissolved in saline, or saline alone (control). The effect of single-dose and 2-week daily treatment was assessed using a muscle function test on the Tibialis Anterior (TA) muscle in situ in anaesthetised mice. The test comprises a warm up, measurement of the force-frequency relationship and a series of eccentric contractions with a 10% stretch that have previously been shown to cause a drop in maximum force in mdx mice. After 2 weeks of P188 treatment at either 30 or 460 mg/kg/day the drop in maximum force produced following eccentric contractions was significantly greater than that seen in saline treated control mice (P = 0.0001). Two week P188 treatment at either dose did not significantly change the force-frequency relationship or maximum isometric specific force produced by the TA muscle. In conclusion P188 treatment increases susceptibility to contraction-induced injury following eccentric contractions in dystrophic skeletal muscle and hence its suitability as a potential therapeutic for DMD should be reconsidered

A Model Analysis of Arterial Oxygen Desaturation during Apnea in Preterm Infants

Rapid arterial O2 desaturation during apnea in the preterm infant has obvious clinical implications but to date no adequate explanation for why it exists. Understanding the factors influencing the rate of arterial O2 desaturation during apnea () is complicated by the non-linear O2 dissociation curve, falling pulmonary O2 uptake, and by the fact that O2 desaturation is biphasic, exhibiting a rapid phase (stage 1) followed by a slower phase when severe desaturation develops (stage 2). Using a mathematical model incorporating pulmonary uptake dynamics, we found that elevated metabolic O2 consumption accelerates throughout the entire desaturation process. By contrast, the remaining factors have a restricted temporal influence: low pre-apneic alveolar causes an early onset of desaturation, but thereafter has little impact; reduced lung volume, hemoglobin content or cardiac output, accelerates during stage 1, and finally, total blood O2 capacity (blood volume and hemoglobin content) alone determines during stage 2. Preterm infants with elevated metabolic rate, respiratory depression, low lung volume, impaired cardiac reserve, anemia, or hypovolemia, are at risk for rapid and profound apneic hypoxemia. Our insights provide a basic physiological framework that may guide clinical interpretation and design of interventions for preventing sudden apneic hypoxemia