Development of Targeted Lipid Nanoparticles for Delivery of siRNA to Neuroblastoma

High-risk neuroblastoma is an aggressive childhood cancer, for which 5-year survival remains less than 50%. Current therapies are non-specific and can lead to acute and long-term side effects. Improved therapies that directly target tumour associated genes are required. Polo-like kinase 1 (PLK1) regulates cell cycle progression, and its over expression in tumours encourages growth. Gene silencing using short interfering RNA (siRNA), is a selective method to target PLK1, with reduced off-target effects. However, efficient delivery of siRNA to tumours requires improved delivery vehicles. Whilst lipid nanoparticles (LNPs) are the most clinically advanced RNA delivery vehicle, clinical siRNA-LNPs exhibit rapid accumulation in liver tissue. I hypothesised that changes in LNP formulation, and active targeting of LNPs to antigens such as epidermal growth factor receptor (EGFR) and disialoganglioside GD2 would improve siRNA delivery to neuroblastoma. siRNA-LNPs were formulated with PEG-lipids that have different detachment kinetics from the LNP surface; DMG-PEG (fast detachment), DSG-PEG and DSPE-PEG (slow detachment). Bispecific antibodies (BsAbs) that recognise either EGFR or GD2 and PEG were used to create targeted LNPs. EGFR targeting improved uptake of siRNA-LNPs in high EGFR-expressing SH-SY5Y neuroblastoma cells in vitro. Similarly, GD2 targeting improved uptake of siRNA-LNPs in GD2-expressing CHP-134 cells. BsAb targeting of LNPs containing PLK1 siRNA (siPLK1-LNPs) resulted in improved PLK1 silencing efficiency compared to untargeted siPLK1-LNPs. Additionally, GD2 targeting reduced the IC50 of siPLK1-LNPs up to 13-fold in CHP-134 cells. Next, the biodistribution of siPLK1-LNPS with and without BsAbs was compared in a neuroblastoma xenograft model. We found that DSG-PEG or DSPE-PEG had higher tumour accumulation compared to DMG-PEG siPLK1-LNPs. However, the presence of BsAb did not significantly impact tumour accumulation. Finally, efficacy studies with untargeted and GD2-targeted siPLK1-LNPs demonstrated that siPLK1 has anti-tumour effects in vivo, although further work is required to optimise therapeutic delivery. In conclusion, this study demonstrates the potential of BsAb targeting and increased PEG-lipid stabilities in improving cell specific uptake and PLK1 gene silencing in neuroblastoma

Improving language-focused comprehension instruction in primary-grade classrooms:impacts of the Let’s Know! experimental curriculum

This quasi-experimental study was designed to test the impacts of a curriculum supplement, Let’s Know! on the quantity and quality of language-focused comprehension instruction in pre-Kindergarten to third grade classrooms. Sixty classrooms (12 per each of pre-K to grade 3) were enrolled in the study, with 40 teachers assigned to implement one of two versions of the experimental Let’s Know! curriculum and 20 assigned to a control condition, in which they maintained their typical language-arts curriculum. Classroom observations, 90 minutes in duration, were collected near the end of the first unit’s completion, about four to five weeks into the academic year. These observations were coded to examine impacts of Let’s Know! instruction on two outcomes: (a) teachers’ use of 18 language-focused comprehension supports, and (b) general classroom quality. Study results using quantile regression showed that Let’s Know! teachers used a significantly higher number of language-focused comprehension supports during Let’s Know! instruction compared to the control teachers during language-arts instruction; the same finding was also true for general classroom quality. Quantile regression results showed the greatest differentiation in instructional quality, when comparing experimental and control teachers, for teachers in the middle of the distribution of general classroom quality. Study findings highlight the value of language-focused curricula for heightening comprehension-specific supports in pre-K to grade 3 settings

QGIS: Projections & Enabling on the Fly Projection

Welcome to the Essential ArcGIS Task Sheet Series. This series supplements the Iowa State University GIS Geospatial Technology Training Program short course series, “Essential ArcGIS Tutorial Series.” The task sheets are designed to provide quick, easy instructions for performing specific tasks in GIShttps://lib.dr.iastate.edu/extension_pubs/1181/thumbnail.jp

The Indian Residential Schools Settlement Agreement's Common Experience Payment and Healing: A Qualitative Study Exploring Impacts on Recipients

This study reports on how the common experience payment has impacted Survivors and their healing

Effect of the differences in protein structure on digestibility

Food is a complex combination of chemically diverse structures, influenced by composition andprocessing. The nutritional quality of food cannot be solely based on individual contents in nutrientsas food structure will strongly modulate the bioaccessibility of nutrients upon digestion. In previousstudies, the most common approach for measuring the extent of proteolysis and nutrient uptake wasto compare the initial macroscopic features of ingested food to final concentrations in thebloodstream. However, there is limited literature to the support underlying mechanisms of thedigestion of food in the stomach and enzyme diffusion in solid food substrates. In the present work,the influence of casein protein gel microstructure on enzymatic digestion was investigated for thefuture development of personalised foods. Casein gels with an identical composition, but differing bythe coagulation mode, were characterized and submitted to simulated gastric digestion. The changesin gel structure over time were studied using confocal microscopy and small angle x-ray scattering(SAXS). The molecular interactions that occur as a gel network is formed, and subsequently brokendown under digestive conditions will be discussed

Using experience-based design to understand the patient and caregiver experience with delirium

Hospital-acquired delirium negatively affects clinical outcomes and the care experience for patients and family caregivers. Following the qualitative methods of experience-based design, we completed observations of hospital units and interviews of patients, caregivers (including family members and other companions), and hospital nurses and other staff regarding their experiences with delirium. In addition, we administered an experience-based design questionnaire to another 130 subjects from the same groups. Key findings included: there is a need for preparation of the patients and family caregivers for the possibility of delirium (particularly before surgery), and patients and caregivers lack understanding of delirium and its potential prolonged aftereffects. We identified that caregivers may both contribute and detract from delirium care as they: (1) often identify delirium early; (2) are invaluable for supporting patients during re-orientation after delirium episodes; (3) frequently lack the preparation and skills for adequate delirium detection and response; (4) may not be present at critical times; (5) can be challenging for the delirium management team, and (6) are frequently discussed as the person who best understands the patients’ baseline cognitive state and behavior. Experience-based design is an innovative framework to increase our qualitative understanding of the patient and caregiver experience during and following episodes of hospital acquired delirium

Interpreting Sequence-Levenshtein distance for determining error type and frequency between two embedded sequences of equal length

Levenshtein distance is a commonly used edit distance metric, typically applied in language processing, and to a lesser extent, in molecular biology analysis. Biological nucleic acid sequences are often embedded in longer sequences and are subject to insertion and deletion errors that introduce frameshift during sequencing. These frameshift errors are due to string context and should not be counted as true biological errors. Sequence-Levenshtein distance is a modification to Levenshtein distance that is permissive of frameshift error without additional penalty. However, in a biological context Levenshtein distance needs to accommodate both frameshift and weighted errors, which Sequence-Levenshtein distance cannot do. Errors are weighted when they are associated with a numerical cost that corresponds to their frequency of appearance. Here, we describe a modification that allows the use of Levenshtein distance and Sequence-Levenshtein distance to appropriately accommodate penalty-free frameshift between embedded sequences and correctly weight specific error types.Comment: 10 pages, 8 figure

Dependent infrastructure system modeling: A case study of the St. Kitts power and water distribution systems

Critical infrastructure systems underlie the economy, national security, and health of modern society. These infrastructures have become increasingly dependent on each other, which poses challenges when modeling these systems. Although a number of methods have been developed for this problem, few case studies that model real-world dependent infrastructures have been conducted. In this paper, we aim to provide another example of such a case study by modeling a real-world water distribution system dependent on a power system. Unlike in the limited previous case studies, our case study is in a developing nation context. This makes the availability of data about the infrastructure systems in this case study very limited, which is a common characteristic of real-world studies in many settings. Thus, a main contribution of the paper is to show how one can still develop representative, useful models for systems in the context of limited data. To demonstrate the utility of these types of models, two examples of different analyses are performed, where the results provide information about the most vulnerable parts of the infrastructures and critical linkages between the power and water distribution systems.publishedVersio