26 research outputs found
Synergistic development of an engineered biodegradable theranostic probe and lymph node organ-on-a-chip to study nanoparticle-lymphatic interactions
No full textThe lymphatic system plays a vital role in controlling immune response. Despite this, cancer often reshapes the lymphatic microenvironment and metastasizes into lymph nodes. Theranostic (therapeutic + diagnostic) nanoparticles have been used in a variety of applications, including the detection and treatment of cancer metastases in lymph nodes. However, accumulation in the liver remains a major concern with any nanoparticle-based intervention. We have developed biodegradable nanoparticles made of biliverdin, an endogenous fluorophore that results from the breakdown of hemoglobin. We demonstrated the degradation of biliverdin nanoparticles (BVNPs) in the presence of biliverdin reductase, as well as the use of BVNPs in photoacoustic imaging of sentinel lymph nodes. Fundamental studies on BVNPs demonstrated shifts in their spectral properties as a response to various stimuli, including pH changes, metal chelation, and UV irradiation. BVNPs loaded with doxorubicin (Dox-BVNPs) were used for treatment of triple-negative breast cancer. BVNPs were further modified via metal chelation for use as a magnetic resonance imaging contrast agent. Finally, hybrid biliverdin-silica particles were developed for use in fluorescence imaging in the near-infrared I and II windows. At the same time, microfluidic models were created to recapitulate the lymph node tissue microenvironment. We first developed a lymphatic vessel on-a-chip that achieved long-term culture of primary human lymphatic endothelial cells (HLECs) under gravity-driven flow. We then developed a lymphatic system on-a-chip, comprised of multiple units that each model the lymph node subscapsular sinus, high endothelial venules, and lymph nodules. This device allows for the exploration of transport of nanoparticles, cancer cells, and immune cells to and from lymph nodes.Submission published under a 24 month embargo labeled 'Closed Access', the embargo will last until 2022-08-01The student, Parinaz Fathi, accepted the attached license on 2020-05-27 at 09:47.The student, Parinaz Fathi, submitted this Dissertation for approval on 2020-05-27 at 10:25.This Dissertation was approved for publication on 2020-06-17 at 15:05.DSpace SAF Submission Ingestion Package generated from Vireo submission #15422 on 2020-10-02 at 15:48:56Made available in DSpace on 2020-10-07T22:48:04Z (GMT). No. of bitstreams: 3
FATHI-DISSERTATION-2020.pdf: 27458256 bytes, checksum: 17880d1a44e4f24438dde7e96a8dad85 (MD5)
LICENSE.txt: 4210 bytes, checksum: b2f6e6970694ac3bc3e89296ed220a44 (MD5)
PROQUEST_LICENSE.txt: 4556 bytes, checksum: 6a4f7aaef7517e37ebe8556f98fcbadc (MD5)
Previous issue date: 2020-06-17Embargo set by: Seth Robbins for item 116284
Lift date: 2022-10-07T22:48:14Z
Reason: Author requested closed access (OA after 2yrs) in Vireo ETD systemEmbargo set by: Seth Robbins for item 116284
Lift date: 2022-10-07T22:50:13Z
Reason: Author requested closed access (OA after 2yrs) in Vireo ETD systemAuthor requested closed access (OA after 2yrs) in Vireo ETD systemLimite
Personalized absorbable gastrointestinal stents for intestinal fistulae and perforations
No full textGastrointestinal (GI) tract perforations and obstructions are relatively frequent surgical emergencies, are potentially life-threatening, and can occur from several different sources. In general, treatment requires urgent surgical repair or resection and at times can lead to further complications. Currently available stents are non-absorbable, are manufactured in a narrow size range, and/or are limited to usage in locations that are accessible for endoscopic removal post-healing. The use of 3D-printed bioresorbable polymeric stents will provide patients with a stent that can prevent leakage, is tailored specifically to their geometry, will degrade with time to eliminate the need for further surgeries for stent removal post-healing, and will be usable in locations that are not endoscopically accessible. This project focused on the characterization of polycaprolactone-polydioxanone (PCL-PDO) composites for use in a bioresorbable gastrointestinal stent. Dynamic Mechanical Analysis (DMA) tests were conducted to separately analyze the effects of composition, the filament formation process, and physiological temperature on the PCL-PDO material properties. The proposed stent design was then modelled using computer-aided design, and Finite Element Analysis (FEA) was used to simulate the effects of physiologically relevant forces on stent integrity. The presence of hydrolysable ester bonds was confirmed using FTIR spectroscopy, and composite morphology was examined with scanning electron microscopy. In vitro studies were used to evaluate the biocompatibility of the polymer composite, finding that the PCL:PDO filament had no negative impact on cell viability over a period of 48 hours, and in fact was conducive to cell proliferation over a period of 3 days. PCL-PDO stents were then 3D-printed and placed in vivo in a pig model, and histological evaluation was used to determine the safety of these stents. Further analyses were conducted through stent placement in ex vivo pig intestines.Submission published under a 24 month embargo labeled 'Closed Access', the embargo will last until 2019-12-01The student, Parinaz Fathi, accepted the attached license on 2017-12-08 at 10:42.The student, Parinaz Fathi, submitted this Thesis for approval on 2017-12-08 at 10:49.This Thesis was approved for publication on 2017-12-12 at 09:02.DSpace SAF Submission Ingestion Package generated from Vireo submission #11917 on 2018-03-13 at 10:37:57Made available in DSpace on 2018-03-13T17:35:52Z (GMT). No. of bitstreams: 3
FATHI-THESIS-2017.pdf: 1901157 bytes, checksum: 828764aaf1e79b24190fd0d4a52cddd8 (MD5)
Draft_120817 - Dept review.docx: 9783017 bytes, checksum: ec2fc5cebde3a443185ba7e4e3eb3273 (MD5)
LICENSE.txt: 4210 bytes, checksum: 111b8b43508f67df5ce0c0280e807410 (MD5)
Previous issue date: 2017-12-12Embargo set by: Seth Robbins for item 105490
Lift date: 2020-03-13T17:36:05Z
Reason: Author requested closed access (OA after 2yrs) in Vireo ETD systemLimited Restriction Lifted for Item 105490 on 2020-03-14T09:15:16Z
Nanoplatelet
No full textMy current research focuses on manipulating materials at the nanoscale in order to use them for applications in furthering human health. To achieve this, I have been utilizing biologically derived materials to synthesize nanoparticles. Nanoparticles have a wide variety of applications in imaging the body and in treating diseases. The nanoplatelets in this image are one example of the types of nanoparticles that I have synthesized. Achieving unique shapes like this at the nanoscale provides an understanding of how different materials interact with each other, and these shapes can even open new doors for the applications of nanomaterials.Open Restriction set for Item 110850 on 2019-05-09T20:16:53Z with date null by [email protected] by Emilie Staubs ([email protected]) on 2019-05-09T20:18:02Z
No. of bitstreams: 2
Parinaz Fathi.pdf: 1205368 bytes, checksum: 6d7cf25d43d07206888f10edb552a892 (MD5)
Parinaz Fathi.pdf: 1192395 bytes, checksum: 00d3b03471b7c510b9caea0b7dfa236e (MD5)Made available in DSpace on 2019-05-09T20:18:02Z (GMT). No. of bitstreams: 2
Parinaz Fathi.pdf: 1205368 bytes, checksum: 6d7cf25d43d07206888f10edb552a892 (MD5)
Parinaz Fathi.pdf: 1192395 bytes, checksum: 00d3b03471b7c510b9caea0b7dfa236e (MD5)
Previous issue date: 2019Ope
Microscopic Roses and Thorns on a Metal Surface
No full textWhen we look at a piece of metal, we usually don’t think about what it looks like at the microscale. Through simple surface modifications, however, a seemingly smooth surface can be formed into one containing geometries that resemble those found in nature. In this image, a metal surface has been modified to form microscopic “roses” and “thorns.” Through these simple reactions, we can make the surface both aesthetic and functional. These kinds of metal surfaces have a wide variety of potential applications in treating, preventing, or detecting diseases, and I am currently exploring the use of this surface as an antibacterial agent. The presence of the microscopic patterns on the metal surface provides higher surface area for interaction between the surface and the bacteria.Open Restriction set for Item 114352 on 2020-04-13T20:17:36Z with date null by [email protected] by Emilie Staubs ([email protected]) on 2020-04-13T20:21:03Z
No. of bitstreams: 1
Fathi, Parinaz.jpg: 172354 bytes, checksum: 1049577377c28393c962081d5b0a906e (MD5)Made available in DSpace on 2020-04-13T20:21:03Z (GMT). No. of bitstreams: 1
Fathi, Parinaz.jpg: 172354 bytes, checksum: 1049577377c28393c962081d5b0a906e (MD5)
Previous issue date: 2020Ope
Personalized absorbable gastrointestinal stents for intestinal fistulae and perforations
No full textGastrointestinal (GI) tract perforations and obstructions are relatively frequent surgical emergencies, are potentially life-threatening, and can occur from several different sources. In general, treatment requires urgent surgical repair or resection and at times can lead to further complications. Currently available stents are non-absorbable, are manufactured in a narrow size range, and/or are limited to usage in locations that are accessible for endoscopic removal post-healing. The use of 3D-printed bioresorbable polymeric stents will provide patients with a stent that can prevent leakage, is tailored specifically to their geometry, will degrade with time to eliminate the need for further surgeries for stent removal post-healing, and will be usable in locations that are not endoscopically accessible. This project focused on the characterization of polycaprolactone-polydioxanone (PCL-PDO) composites for use in a bioresorbable gastrointestinal stent. Dynamic Mechanical Analysis (DMA) tests were conducted to separately analyze the effects of composition, the filament formation process, and physiological temperature on the PCL-PDO material properties. The proposed stent design was then modelled using computer-aided design, and Finite Element Analysis (FEA) was used to simulate the effects of physiologically relevant forces on stent integrity. The presence of hydrolysable ester bonds was confirmed using FTIR spectroscopy, and composite morphology was examined with scanning electron microscopy. In vitro studies were used to evaluate the biocompatibility of the polymer composite, finding that the PCL:PDO filament had no negative impact on cell viability over a period of 48 hours, and in fact was conducive to cell proliferation over a period of 3 days. PCL-PDO stents were then 3D-printed and placed in vivo in a pig model, and histological evaluation was used to determine the safety of these stents. Further analyses were conducted through stent placement in ex vivo pig intestines
Affordance Theory in XR Design : A Designer’s Perspective
No full textThis thesis explores the application of Affordance Theory in creating virtual learning environments, particularly in the context of the Agile XR project. The author, an experienced spatial designer with a decade and a half of expertise, concentrates on redesigning the user-friendliness and immersion of a virtual world called Dana’s Mind. In implementing the Affordance Theory, the author orientates to two significant literatures, The Ecological Approach to Visual Perception (Gibson,1979) and The Design of Everyday Things (Norman, 2013). Affordance Theory can be separated into two views.
Gibson’s perspective highlights the significance of environmental clues in indicating potential actions, regarding objects not just as static entities but as invitations for action. Expand upon this concept by introducing the concept of “perceived affordances,” highlighting the significance of making these signals clear in design to improve user comprehension without relying on instruction manuals.
This study utilizes a first-person study methodology, where the author actively participates in Dana’s Mind, carefully documenting their encounters and findings. The study is enhanced by feedback from teachers who participated in the Agile XR project, which offers significant insights into user interactions. Subsequent redesign combines theoretical ideas and practical feedback to keep the original design’s style while improving user-centric aspects.
In terms of the study's research participation, this study utilizes a dual-method approach: the author evaluates the revised virtual area, replicating their first experience, while eight other individuals give extra opinions through a survey. Findings emphasize the influence of Affordance Theory on user engagement and highlight its function in establishing a consistent and user-friendly virtual learning environment.
This study suggests that Affordance Theory is a highly effective tool for designers, serving as an advantage in XR design for online education and optimizing the user interface of virtual elements to be intuitive and user-friendly, guaranteeing a smooth and effortless experience for students and teachers. The paper claims that Affordance Theory is crucial for improving XR design, which transforms online learning spaces into settings where navigation is efficient and intuitively simple
A Survey On Hybrid Routing Protocols In MANETS
No full textMobile Ad hoc NETwork (MANET) is a collection of mobile nodes that are arbitrarily located so that the interconnections between nodes are dynamically changing. A routing protocol is used to find routes between mobile nodes to facilitate communication wi thin the network. The main goal of such an ad hoc network routing protocol is to establish correct and efficient route between a pair of mobile nodes. Route should be discovered and maintained with a minimum of overhead and bandwidth consumption. There are number of routing protocols were proposed for ad hoc networks. T he objective of this paper is to create a taxonomy of the ad hoc hybrid routing protocols, and to survey and comp are each type of hybrid protocols. We try to show the requirements considered by the different hybrid protocols, the resource limitations under which they operate, and the design decisions made by the author
Impact of Clinically Relevant Elliptical Deformations on the Damage Patterns of Sagging and Stretched Leaflets in a Bioprosthetic Heart Valve
No full text
