Development of Next Generation 3-Dimensional In vitro Soft Tissues Models for Biomaterial Testing: Controlling Construct Properties with Fluid Flow

Pre-clinical biomaterial development and testing have traditionally relied on 2D in vitro, or complex in vivo assays. It is essential for the cell environment to match the natural tissue in terms of matrix density, architecture, components (including stress/strains) for tissue models to behave in a natural manner. The aim of this project is to improve existing in vitro models for the biomaterial testing. Plastically compressed collagen hydrogels were used to create a simple and accessible 3D model. Improvement in hydrogel stiffness was achieved using pre-crosslinked, polymeric collagen, as a starting material. Hydrogels were formed by blending polymeric and monomeric collagens, which delayed the aggregation of collagen fibrils, and enabled cell incorporation at physiological pH. Plastic compression of the novel hydrogel resulted in stiffer constructs; however, during compression, cells were exposed to reversible (i.e. using mobile macromolecules) increases in cell-damaging fluid shear stresses. In the material degradation model, it was found that the release rates of PLGA degradation products were influenced by cells in the collagen matrix; and differed significantly between 2D (24 hours) and 3D (7 days) models. Imaging of cells cultured within the biomaterial also demonstrate the up-take of biomaterials within cells within the model after 10 days in culture. Nanoparticle drug delivery via hyaluronan nanoparticle (HA-NP) was improved by increasing blockage at the fluid leaving surface (FLS). The HA-NP was designed to gradually release trapped simvastatin, which was measured indirectly via BMP2 production over time. Although results were inconclusive, initial experiments demonstrated sustained BMP2 production by cells over 5-9 days. This work has demonstrated novel ways to improve the stiffness of the model construct, and an improved understanding of particle movement within the hydrogel during plastic compression. The models for biomaterial testing have demonstrated that it was possible to track biomaterials in the construct/ cells over time, enabling real-time monitoring of the biomaterial and cells at the implant site

A relocatable ocean model in support of environmental emergencies

During the Costa Concordia emergency case, regional, subregional, and relocatable ocean models have been used together with the oil spill model, MEDSLIK-II, to provide ocean currents forecasts, possible oil spill scenarios, and drifters trajectories simulations. The models results together with the evaluation of their performances are presented in this paper. In particular, we focused this work on the implementation of the Interactive Relocatable Nested Ocean Model (IRENOM), based on the Harvard Ocean Prediction System (HOPS), for the Costa Concordia emergency and on its validation using drifters released in the area of the accident. It is shown that thanks to the capability of improving easily and quickly its configuration, the IRENOM results are of greater accuracy than the results achieved using regional or subregional model products. The model topography, and to the initialization procedures, and the horizontal resolution are the key model settings to be configured. Furthermore, the IRENOM currents and the MEDSLIK-II simulated trajectories showed to be sensitive to the spatial resolution of the meteorological fields used, providing higher prediction skills with higher resolution wind forcing.MEDESS4MS Project; TESSA Project; MyOcean2 Projectinfo:eu-repo/semantics/publishedVersio

Effectiveness of Biosecurity Measures in Preventing Badger Visits to Farm Buildings

This is the final version of the article. Available from Public Library of Science via the DOI in this record.BACKGROUND: Bovine tuberculosis caused by Mycobacterium bovis is a serious and economically important disease of cattle. Badgers have been implicated in the transmission and maintenance of the disease in the UK since the 1970s. Recent studies have provided substantial evidence of widespread and frequent visits by badgers to farm buildings during which there is the potential for close direct contact with cattle and contamination of cattle feed. METHODOLOGY: Here we evaluated the effectiveness of simple exclusion measures in improving farm biosecurity and preventing badger visits to farm buildings. In the first phase of the study, 32 farms were surveyed using motion-triggered infrared cameras on potential entrances to farm buildings to determine the background level of badger visits experienced by each farm. In the second phase, they were divided into four treatment groups; "Control", "Feed Storage", "Cattle Housing" and "Both", whereby no exclusion measures were installed, exclusion measures were installed on feed storage areas only, cattle housing only or both feed storage and cattle housing, respectively. Badger exclusion measures included sheet metal gates, adjustable metal panels for gates, sheet metal fencing, feed bins and electric fencing. Cameras were deployed for at least 365 nights in each phase on each farm. RESULTS: Badger visits to farm buildings occurred on 19 of the 32 farms in phase one. In phase two, the simple exclusion measures were 100% effective in preventing badger entry into farm buildings, as long as they were appropriately deployed. Furthermore, the installation of exclusion measures also reduced the level of badger visits to the rest of the farmyard. The findings of the present study clearly demonstrate how relatively simple practical measures can substantially reduce the likelihood of badger visits to buildings and reduce some of the potential for contact and disease transmission between badgers and cattle.This work was funded by Defra project number SE3119, http://www.defra.gov.uk/. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript