Insulin-secreting allogeneic cell therapies are a promising treatment for type 1 diabetes, with the potential to eliminate hypoglycemia and long-term complications of the disease. However, chronic systemic immunosuppression is necessary to prevent graft rejection, and the acute risks associated with immunosuppression limit the number of patients who can be treated with allogeneic cell therapies. Islet macroencapsulation in a hydrogel biomaterial is one proposed method to reduce or eliminate immune suppression; however, macroencapsulation devices suffer from poor oxygen transport and limited efficacy as they scale to large animal model preclinical studies and clinical trials.
View Article and Find Full Text PDFOut-of-hospital cardiac arrest (OHCA) occurs in nearly 350,000 people each year in the United States (US). Despite advances in pre and in-hospital care, OHCA survival remains low and is highly variable across systems and regions. The critical barrier to improving cardiac arrest outcomes is not a lack of knowledge about effective interventions, but rather the widespread lack of systems of care to deliver interventions known to be successful.
View Article and Find Full Text PDFThe human placenta is a complex organ comprised of multiple trophoblast subtypes, and inadequate models to study the human placenta limit the current understanding of human placental behavior and development. Common placental models rely on two-dimensional culture of cell lines and primary cells, which do not replicate the native tissue microenvironment, or poorly defined three-dimensional hydrogel matrices such as Matrigel™ that provide limited environmental control and suffer from high batch-to-batch variability. Here, we employ a highly defined, synthetic poly(ethylene glycol)-based hydrogel system with tunable degradability and presentation of extracellular matrix-derived adhesive ligands native to the placenta microenvironment to generate placental spheroids.
View Article and Find Full Text PDFHydrogel injection molding is a biofabrication method that is useful for the rapid generation of complex cell-laden hydrogel geometries, with potential utility in biomanufacturing products for tissue engineering applications. Hydrogel injection molding requires that hydrogel polymers have sufficiently delayed crosslinking times to enable injection and molding prior to gelation. In this work, we explore the feasibility of injection molding synthetic poly(ethylene) glycol (PEG)-based hydrogels functionalized with strain promoted azide-alkyne cycloaddition click chemistry functional groups.
View Article and Find Full Text PDFACS Biomater Sci Eng
September 2022
Biofabrication methods capable of generating complex, three-dimensional, cell-laden hydrogel geometries are often challenging technologies to implement in the clinic and scaled manufacturing processes. Hydrogel injection molding capitalizes on the reproducibility, efficiency, and scalability of the injection molding process, and we adapt this technique to biofabrication using a library of natural and synthetic hydrogels with varied crosslinking chemistries and kinetics. We use computational modeling to evaluate hydrogel library fluid dynamics within the injection molds in order to predict molding feasibility and cytocompatibility.
View Article and Find Full Text PDFLarge-scale nanoarrays of single biomolecules enable high-throughput assays while unmasking the underlying heterogeneity within ensemble populations. Until recently, creating such grids which combine the advantages of microarrays and single-molecule experiments (SMEs) has been particularly challenging due to the mismatch between the size of these molecules and the resolution of top-down fabrication techniques. DNA origami placement (DOP) combines two powerful techniques to address this issue: (i) DNA origami, which provides a ∼100 nm self-assembled template for single-molecule organization with 5 nm resolution and (ii) top-down lithography, which patterns these DNA nanostructures, transforming them into functional nanodevices via large-scale integration with arbitrary substrates.
View Article and Find Full Text PDFBackground/objectives: Childhood obesity has increased enormously. Several lifestyle factors have been implicated, including decreased physical activity, partially involving a decline in active travel to school. We aimed to establish the association between school transport mode and physical activity levels of primary 6 and 7 children (aged 10-12).
View Article and Find Full Text PDFVariation in the shape of the glenoid and periarticular anatomy of the scapula has been associated with shoulder pathology. The goal of this study was to identify the modes of shape variation of periarticular scapular anatomy in relation to the glenoid in nonpathologic shoulders. Computed tomography scans of 31 cadaveric scapulae, verified to be free of pathology, were three-dimensionally reconstructed.
View Article and Find Full Text PDFComposite biomaterials offer a new approach for engineering novel, minimally-invasive scaffolds with properties that can be modified for a range of soft tissue applications. In this study, a new way of controlling the gelation of alginate hydrogels using Ga-based glass particles is presented. Through a comprehensive analysis, it was shown that the setting time, mechanical strength, stiffness and degradation properties of this composite can all be tailored for various applications.
View Article and Find Full Text PDFBackground: Although scapular morphology contributes to glenohumeral osteoarthritis and rotator cuff disease, its role in traumatic glenohumeral instability remains unknown. We hypothesized that coracoacromial and glenoid morphology would differ between healthy subjects and patients with recurrent traumatic anterior shoulder instability.
Methods: Computed tomography scans of 31 cadaveric control scapulae and 54 scapulae of patients with recurrent traumatic anterior shoulder instability and Hill-Sachs lesions were 3-dimensionally reconstructed.
Objectives: Trigger point dry needling (TrP-DN) is commonly used to treat persons with myofascial pain, but no studies currently exist investigating its safety. The aim of this study was to determine the incidence of Adverse Events (AEs) associated with the use of TrP-DN by a sample of physiotherapists in Ireland.
Methods: A prospective survey was undertaken consisting of two forms recording mild and significant AEs.
Acta Crystallogr Sect E Struct Rep Online
January 2014
In the title quaternary ammonium salt, C55H61N4 (+)·I(-), all three N,N-di-benzyl-ethanamine, -(CH2)2N(CH2C6H5)2, groups have different conformations. The N-C-C-N torsion angles are significantly different [89.86 (13), 162.
View Article and Find Full Text PDFIn Alzheimer's disease (AD), the mechanisms of neuronal loss remain largely unknown. Although tau pathology is closely correlated with neuronal loss, how its accumulation may lead to activation of neurotoxic pathways is unclear. Here we show that tau increased the levels of ubiquitinated proteins in the brain and triggered activation of the unfolded protein response (UPR).
View Article and Find Full Text PDFBackground: The microtubule-associated protein tau accumulates in neurodegenerative diseases known as tauopathies, the most common being Alzheimer's disease. One way to treat these disorders may be to reduce abnormal tau levels through chaperone manipulation, thus subverting synaptic plasticity defects caused by tau's toxic accretion.
Methods: Tauopathy models were used to study the impact of YM-01 on tau.
Tau aggregation and amyloidogenesis are common hallmarks for neurodegenerative disorders called tauopathies. The molecular chaperone network constitutes the cellular defense against insults such as tau aggregation. However, chaperone effects on tau are dichotomous.
View Article and Find Full Text PDFAnnu Int Conf IEEE Eng Med Biol Soc
May 2009
This paper details the development of a textile based fluid handling system with integrated wireless biochemical sensors. Such research represents a new advancement in the area of wearable technologies. The system contains pH, sodium and conductivity sensors.
View Article and Find Full Text PDFRapid developments in wireless communications are opening up opportunities for new ways to perform many types of analytical measurements that up to now have been restricted in scope due to the need to have access to centralised facilities. This paper will address both the potential for new applications and the challenges that currently inhibit more widespread integration of wireless communications with autonomous sensors and analytical devices. Key issues are identified and strategies for closer integration of analytical information and wireless communications systems discussed.
View Article and Find Full Text PDFThis paper provides an overview of research conducted in the development of ambulatory devices for wearable sensing applications. Two configurations of wearable sensing are shown, the first a wearable chemosensor in a wrist-watch configuration, and the second a textile with an integrated foam sensor. The foam sensor is composed of polypyrrole-coated polyurethane foam, which exhibits a piezo-resistive response when exposed to electrical current.
View Article and Find Full Text PDFBACKGROUND: This paper provides an overview of initial research conducted in the development of pressure-sensitive foam and its application in wearable sensing. The foam sensor is composed of polypyrrole-coated polyurethane foam, which exhibits a piezo-resistive reaction when exposed to electrical current. The use of this polymer-coated foam is attractive for wearable sensing due to the sensor's retention of desirable mechanical properties similar to those exhibited by textile structures.
View Article and Find Full Text PDF