Publications by authors named "Patrick A Armstrong"

Photocrosslinking hydrogel technologies are attractive for the biofabrication of cardiovascular soft tissues, but 3D printing success is dependent on multiple variables. In this study we systematically test variables associated with photocrosslinking hydrogels (photoinitiator type, photoinitiator concentration, and light intensity) for their effects on encapsulated cells in an extrusion 3D printable mixture of methacrylated gelatin/poly-ethylene glycol diacrylate/alginate (MEGEL/PEGDA3350/alginate). The fabrication conditions that produced desired hydrogel mechanical properties were compared against those that optimize aortic valve or mesenchymal stem cell viability.

View Article and Find Full Text PDF

High-efficiency upconverted light would be a desirable stimulus for triggered drug delivery. Here we present a general strategy to achieve photoreactions based on triplet-triplet annihilation upconversion (TTA-UC) and Förster resonance energy transfer (FRET). We designed PLA-PEG micellar nanoparticles containing in their cores hydrophobic photosensitizer and annihilator molecules which, when stimulated with green light, would undergo TTA-UC.

View Article and Find Full Text PDF

Genetically engineered mice are valuable models for elucidation of auditory and vestibular pathology. Our goal was to establish a comprehensive vestibular function testing system in mice using: (1) horizontal angular vestibulo-ocular reflex (hVOR) to evaluate semicircular canal function and (2) otolith-ocular reflex (OOR) to evaluate otolith organ function and to validate the system by characterizing mice with vestibular dysfunction. We used pseudo off-vertical axis rotation to induce an otolith-only stimulus using a custom-made centrifuge.

View Article and Find Full Text PDF

Background: The purpose of this study was to determine the prevalence of vitamin D deficiency in CTCL patients and whether supplementation corrects vitamin D deficiency or treatment outcome.

Patients And Methods: Three hundred eleven CTCL patients including 27/311 (8.7%) with Sézary syndrome (SS), 169 cancer controls, and 69 normal controls from the M.

View Article and Find Full Text PDF

Tissue engineering-based approaches have the potential to improve stem cell engraftment by increasing cell delivery to the myocardium. Our objective was to develop and characterize a naturally-derived, autologous, biodegradable hydrogel in order to improve acute stem cell retention in the myocardium. HA-blood hydrogels (HA-BL) were synthesized by mixing in a 1:1(v/v) ratio, lysed whole blood and hyaluronic acid (HA), whose carboxyl groups were functionalized with N-hydroxysuccinimide (NHS) to yield HA succinimidyl succinate (HA-NHS).

View Article and Find Full Text PDF

A 19-year-old woman with a known allergy to iodinated contrast presented with intermittent, gross hematuria of 2 years' duration. The patient was scheduled to undergo cystoscopy with bilateral retrograde pyelography, because this is considered a safe alternative to intravenous pyelography or computed tomography. Because of her contrast allergy, the patient completed a 13-hour steroid preparation before the procedure.

View Article and Find Full Text PDF