Endogenous musculoskeletal tissue engineering - a focused perspective

Two major difficulties facing widespread clinical implementation of existing Tissue Engineering (TE) strategies for the treatment of musculoskeletal disorders are (1) the cost, space and time required for ex vivo culture of a patient’s autologous cells prior to re-implantation as part of a TE construct, and (2) the potential risks and availability constraints associated with transplanting exogenous (foreign) cells. These hurdles have led to recent interest in endogenous TE strategies, in which the regenerative potential of a patient’s own cells is harnessed to promote tissue regrowth without ex vivo cell culture. This article provides a focused perspective on key issues in the development of endogenous TE strategies, progress to date, and suggested future research directions toward endogenous repair and regeneration of musculoskeletal tissues and organs

Porous zirconia scaffold modified with mesoporous bioglass coating

Porous yttria-stabilized zirconia (YSZ) has been regarded as a potential candidate for bone substitute as its high mechanical strength. However, porous YSZ bodies are biologically inert to bone tissue. It is therefore necessary to introduce bioactive coatings onto the walls of the porous structures to enhance the bioactivity. In this study, the porous zirconia scaffolds were prepared by infiltration of Acrylonitrile Butadiene Styrene (ABS) scaffolds with 3 mol% yttria stabilized zirconia slurry. After sintering, a method of sol-gel dip coating was involved to make coating layer of mesoporous bioglass (MBGs). The porous zirconia without the coating had high porosities of 60.1% to 63.8%, and most macropores were interconnected with pore sizes of 0.5-0.8mm. The porous zirconia had compressive strengths of 9.07-9.90MPa. Moreover, the average coating thickness was about 7μm. There is no significant change of compressive strength for the porous zirconia with mesoporous biogalss coating. The bone marrow stromal cell (BMSC) proliferation test showed both uncoated and coated zirconia scaffolds have good biocompatibility. The scanning electron microscope (SEM) micrographs and the compositional analysis graphs demonstrated that after testing in the simulated body fluid (SBF) for 7 days, the apatite formation occurred on the coating surface. Thus, porous zirconia-based ceramics were modified with bioactive coating of mesoporous bioglass for potential biomedical applications

Ability of modal analysis to detect osseointegration of implants in transfemoral amputees : a physical model study

Owing to the successful use of non-invasive vibration analysis to monitor the progression of dental implant healing and stabilization, it is now being considered as a method to monitor femoral implants in transfemoral amputees. This study uses composite femur-implant physical models to investigate the ability of modal analysis to detect changes at the interface between the implant and bone simulating those that occur during osseointegration. Using electromagnetic shaker excitation, differences were detected in the resonant frequencies and mode shapes of the model when the implant fit in the bone was altered to simulate the two interface cases considered: firm and loose fixation. The study showed that it is beneficial to examine higher resonant frequencies and their mode shapes (rather than the fundamental frequency only) when assessing fixation. The influence of the model boundary conditions on the modal parameters was also demonstrated. Further work is required to more accurately model the mechanical changes occurring at the bone-implant interface in vivo, as well as further refinement of the model boundary conditions to appropriately represent the in vivo conditions. Nevertheless the ability to detect changes in the model dynamic properties demonstrates the potential of modal analysis in this application and warrants further investigation

The measurement of applied forces during anterior single rod correction of adolescent idiopathic scoliosis

Adolescent idiopathic scoliosis (AIS) is the most common form of spinal deformity in paediatrics, prevalent in approximately 2-4% of the general population. While it is a complex three-dimensional deformity, it is clinically characterised by an abnormal lateral curvature of the spine. The treatment for severe deformity is surgical correction with the use of structural implants. Anterior single rod correction employs a solid rod connected to the anterior spine via vertebral body screws. Correction is achieved by applying compression between adjacent vertebral body screws, before locking each screw onto the rod. Biomechanical complication rates have been reported as high as 20.8%, and include rod breakage, screw pull-out and loss of correction. Currently, the corrective forces applied to the spine are unknown. These forces are important variables to consider in understanding the biomechanics of scoliosis correction. The purpose of this study was to measure these forces intra-operatively during anterior single rod AIS correction

A computer model to simulate scoliosis surgery

Use of patient-specific computer models as a pre-operative planning tool permits predictions of the likely deformity correction and allows a more detailed investigation of the biomechanical influence of different surgical procedures on the scoliotic spinal anatomy. In this paper, patient-specific computer models are used of adolescent idiopathic scoliosis patients who underwent a single rod anterior procedure at the Mater Children’s Hospital in Brisbane, to predict deformity correction and to investigate the change in biomechanics of the scoliotic spine due to surgical compressive forces applied during implant placement

Analyzing the detection efficiency of the Geostationary Lightning Mapper in isolated convection

2021 Spring.Includes bibliographical references.The Geostationary Lightning Mapper (GLM) flying on GOES-16 and GOES-17 has provided near-hemispheric lightning detection for nearly two years. Since operation began, several attempts have been made to compare flash rate observations from GLM against ground-based lightning detection systems. While GLM captures a high percentage of flashes in the field-of-view of GOES-16 and GOES-17, some studies have shown reduced detection efficiency at storm-scale. The problem of analyzing lightning from space is a complex one. Several factors such as: flash area, flash length, cloud water and ice contents, flash height, flash brightness and position relative to satellite nadir affect the detection efficiency of GLM. This study analyzes numerous convective cells in the Alabama, Colorado, and W. Texas regions to further analyze the detection efficiency of GLM. Lightning data from VHF-based lightning mapping arrays (LMAs) in each region were compared directly to measurements from GLM. The GLM/LMA ratio for each cell was computed during the lifetime of the thunderstorm. Additionally, graupel echo volumes, precipitation ice water paths, and cloud ice and cloud water paths were calculated to access the microphysics of each cell. This study features an in-depth analysis of thunderstorms that vary in size and severity from each region. Further, a statistical analysis of all of the variables was performed to determine the major factors that affect GLM detection efficiency. This study found that flash rate, flash brightness and near cloud-top water and ice water paths significantly affect GLM detection efficiency. Specifically, thunderstorms with increased flash rates, cloud-top water paths, and decreased flash size/brightness are often characterized by low (< 20%) GLM detection efficiencies. These characteristics are common in so-called "anomalous" charge structure thunderstorms that frequent the northern Colorado region. Additionally, this study confirmed results from previous studies which found that the GLM DE decreases as the distance from nadir increases. These results will be helpful for meteorologists utilizing GLM observations to assist with decisions regarding severe weather

Multi-Objective, Multiphasic and Multi-Step Self-Optimising Continuous Flow Systems

Continuous flow chemistry is currently a vibrant area of research, offering many advantages over traditional batch chemistry. These include: enhanced heat and mass transfer, access to a wider range of reaction conditions, safer use of hazardous reagents, telescoping of multi-step reactions and readily accessible photochemistry. As such, there has been an increase in the adoption of continuous flow processes towards the synthesis of active pharmaceutical ingredients (APIs) in recent years. Advances in the automation of laboratory equipment has transformed the way in which routine experimentation is performed, with the digitisation of research and development (R&D) greatly reducing waste in terms of human and material resources. Self-optimising systems combine algorithms, automated control and process analytics for the feedback optimisation of continuous flow reactions. This provides efficient exploration of multi-dimensional experimental space, and accelerates the identification of optimum conditions. Therefore, this technology directly aligns with the drive towards more sustainable process development in the pharmaceutical industry. Yet the uptake of these systems by industrial R&D departments remains relatively low, suggesting that the capabilities of the current technology are still limited. The work in this thesis aims to improve existing self-optimisation technologies, to further bridge the gap between academic and industrial research. This includes introducing multi-objective optimisation algorithms and applying them towards the synthesis of APIs, developing a new multiphasic CSTR cascade reactor with photochemical capabilities and including downstream work-up operations in the optimisation of multi-step processes

Interactive image manipulation for surgical planning

The Australian e-Health Research Centre in collaboration with the Queensland University of Technology's Paediatric Spine Research Group is developing software for visualisation and manipulation of large three-dimensional (3D) medical image data sets. The software allows the extraction of anatomical data from individual patients for use in preoperative planning. State-of-the-art computer technology makes it possible to slice through the image dataset at any angle, or manipulate 3D representations of the data instantly. Although the software was initially developed to support planning for scoliosis surgery, it can be applied to any dataset whether obtained from computed tomography, magnetic resonance imaging or any other imaging modality

Seed Tick: A Palimpsest

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