Characterization of a reversible thermally-actuated polymer-valve: A potential dynamic treatment for congenital diaphragmatic hernia
| Autor: | Anthony Johnson, Justin S. Baba, M. Nance Ericson, Boyd M. Evans, Timothy E. McKnight, Kenneth J. Moise |
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| Rok vydání: | 2018 |
| Předmět: |
0301 basic medicine
Amniotic fluid Medical Implants Polymers Physiology 02 engineering and technology 030105 genetics & heredity Body Temperature Polymerization Fetoscopy Pregnancy Occlusion Medicine and Health Sciences Materials chemistry.chemical_classification Multidisciplinary medicine.diagnostic_test Physics Chemical Reactions Temperature Classical Mechanics Prostheses and Implants Polymer 021001 nanoscience & nanotechnology Diaphragm (structural system) Trachea Chemistry Fetal Diseases Macromolecules Physiological Parameters Obstetric Procedures Physical Sciences Engineering and Technology Medicine Female 0210 nano-technology Research Article Biotechnology Materials science Amorphous Solids Science Materials Science Diaphragmatic breathing Surgical and Invasive Medical Procedures Bioengineering Fluid Mechanics Continuum Mechanics 03 medical and health sciences Fetal Organ Maturity medicine Animals Humans Fluid Flow Biology and Life Sciences Congenital diaphragmatic hernia Fluid Dynamics Polymer Chemistry medicine.disease Valve actuator chemistry Medical Devices and Equipment Glass Hernias Diaphragmatic Congenital Biomedical engineering |
| Zdroj: | PLoS ONE, Vol 13, Iss 12, p e0209855 (2018) PLoS ONE |
| ISSN: | 1932-6203 |
| Popis: | BackgroundCongenital diaphragmatic hernia (CDH) is a fetal defect comprising an incomplete diaphragm and the herniation of abdominal organs into the chest cavity that interfere with fetal pulmonary development. Though the most promising treatment for CDH is via interventional fetoscopic tracheal occlusion (TO) surgery in-utero, it has produced mixed results due to the static nature of the inserted occlusion. We hypothesize that a suitable noninvasively-actuatable, cyclic-release tracheal occlusion device can be developed to enable dynamic tracheal occlusion (dTO) implementation.ObjectiveTo conduct an in-vitro proof-of-concept investigation of the construction of thermo-responsive polymer valves designed for targeted activation within a physiologically realizable temperature range as a first step towards potential development of a noninvasively-actuatable implantable device to facilitate dynamic tracheal occlusion (dTO) therapy.MethodsSix thermo-responsive polymer valves, with a critical solution temperature slightly higher than normal physiological body temperature of 37°C, were fabricated using a copolymer of n-isopropylacrylamide (NIPAM) and dimethylacrylamide (DMAA). Three of the valves underwent ethylene oxide (EtO) sterilization while the other three served as controls for EtO-processing compatibility testing. Thermal response actuation of the valves and their steady-state flow performances were evaluated using water and caprine amniotic fluid.ResultsAll six valves consisting of 0.3-mole fraction of DMAA were tested for thermal actuation of caprine amniotic fluid flow at temperatures ranging from 30-44°C. They all exhibited initiation of valve actuation opening at ~40°C with full completion at ~44°C. The overall average coefficient of variation (CV) for the day-to-day flow performance of the valves tested was less than 12%. Based on a Student t-test, there was no significant difference in the operational characteristics for the EtO processed versus the non-EtO processed valves tested.ConclusionsWe successfully fabricated and demonstrated physiological realizable temperature range operation of thermo-responsive polymer valves in-vitro and their suitability for standard EtO sterilization processing, a prerequisite for future in-vivo surgical implantation testing. |
| Databáze: | OpenAIRE |
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