Allergen immunotherapy or “allergy shots” are delivered as fast-acting intravenous (IV) injections given to patients suffering from chronic allergies. However, in rural settings, patients must travel long distances for a single injection, significantly adding to patient costs, and costs to an already over-burdened health-care system. We hypothesized that minimally invasive, painless, self-administered 3D (three-dimensional) printed microneedles could be a better alternative in these scenarios and could be provided in conjunction with tele-medicine. For this study, 3D printed microneedles were printed using Formlabs stereolithography (SLA) printers and clear V4 material. Different parameters were calibrated including layer thickness, size, shape, material, and needle orientation, to enable dermal puncture with minimal breakage. Our results show that a Pyramid Needle Model (needle array: 1(L)x1(W)x0.5(H) cm; needle dimensions: 200(L)x200(W)x800(H) µm; 500µm (spacing); 1µm (tip diameter); 45° angle; 0.025mm layer-thickness) was the best microneedle model produced through our experiments. Microscopy and porcine skin puncture testing confirmed the functionality of these needles in the laboratory. Taken together, our results showcase the feasibility of fabrication of transdermal microneedles through 3D printing, providing a fast and effective solution for self-administered painless drug delivery. Future work will focus on improving microneedle design to enable allergy-drug loading and delivery.
Development of a system that can deploy a stent graft to peripheral artery with a collateral vessel without blocking the collateral vessel has been undertaken to assist in treating different arterial conditions like atherosclerosis. Currently no commercially available system exists that can deploy a stent graft without inhibiting flow to the collateral vessel; surgeons must create a fenestration in the main graft through which to deploy a smaller device. The fabrication of this system involved modifying and combining prefabricated catheters to make a complete system that can deploy the stent with good turnability. The system has a port to both inject dye and insert a wire to probe for correct placement of the device fenestration. The research effort has produced prototypes of a multi-lumen intravascular catheter deployment system for stent graft placement where a stent graft can be placed via the system and proper fenestration alignment to the collateral vessel can be confirmed. This project could improve patient outcomes by providing a cost effective and safe option for inserting stents into major arteries that have a collateral vessel which is currently treated by surgeons using makeshift solutions with existing stents and ablation tools.
Tumor ablation is an effective, minimally invasive technique for cancer removal. The procedure uses medical imaging and a needle-like probe, which is guided to the target cancerous tissue where it is subsequently heated or cooled to a cytotoxic level. Thus, surrounding tissue must be separated from the cancerous tissue to prevent damage to healthy tissue. Saline and carbon dioxide are current methods of separation, but both migrate from the site due to gravity and cause risk of postoperative pain. To create a stable, stationary, and thermally protective barrier, a biocompatible foam has been developed with FDA-approved materials to optimize tissue separation for a typical 60 minute procedure. As progress continues, further characterization of the foam is being tested using rheology, which mimics deformation during foam injection and quantifies stability as a function of time and deformation rate. Current project goals involve developing a freeze-dried procedure that maximizes the shelf life of the foam and minimizes preparation steps for future commercialization and clinical use. Continued testing is essential for confirming previous qualitative tests of the foam’s material properties and providing data required for publication and implementation of these foams in a clinical setting.
Plastic pollutants are a significant environmental concern. Biodegradable plastics are a large area of research because if plastics are accidentally released into the environment, biodegradable plastics will break down into harmless byproducts. A blister pack is a type of packaging that consists of plastic pockets that hold individual pills. Current blister packs on the market are not biodegradable and contribute to environmental harm. The goal for this research project is to find an eco-friendly material to replace current blister packs that can also handle chemical reagents (such as medical reagents). Initial testing focused on developing a film from cassava starch that was adapted from the literature. The standard ASTM D543 was used to evaluate the resistance of the material to chemical reagents. The samples were placed under strain using a 3D printed strain jig, the chemical reagent was applied, and the samples were held at fixed temperature for varied amounts of time. After chemical exposure, the samples were tested to determine changes in mechanical properties. These results will be used to determine if cassava starch can replace traditional plastic blister packs to open the door to many environmentally friendly swaps in the medical field.
This project seeks to develop a mechanically flexible cooling pad that can be used by medical patients to provide targeted pain or inflammation relief to injured or surgical areas. We are seeking to develop a device that is fully temperature controlled and can be used for long intervals of time up to several hours. We have identified several possible configurations to maximize cooling power while retaining as much geometrical flexibility as possible. We are currently pursuing two distinct cooling methods, and working to engineer a complete system for both methods that is able to sense and adjust temperatures produced by the cooling pad. In this poster we will describe some of the key geometrical and experimental variables under study, and work needed for continued improvement.
Expanded Polytetrafluoroethylene (ePTFE) grafts are commonly used to repair and reconstruct blood vessels in vascular bypass surgeries and peripheral arterial reconstructions. However, current ePTFE grafts often cause scar tissue formation due to their dense structure, limiting long-term effectiveness and integration with the body. The goal of this research is to create an ePTFE graft with properties similar to cells found in an organism so it can fully penetrate, and not have a reaction making a scar tissue. To reach our goal, we expanded and characterized Polytetrafluoroethylene (PTFE), transforming it into ePTFE. The research is currently in a testing phase, where we are evaluating the graft’s performance using Tensile Test, to test their break point, Thermogravimetric Analysis (TGA) to evaluate how the material behaves under different thermal conditions, and Differential Scanning Calorimetry (DSC) to evaluate the melting and thermal behaviors of the sample. These tests help optimize the graft's properties, thermal stability, and biocompatibility, ensuring it can perform effectively within the body and integrate with surrounding tissues.
Caviar refers to processed salted roe obtained from large fish, and it often requires the sacrifice of a pregnant female. With the increasing global human population, the demand for caviar is rapidly growing, threatening wildlife fish populations everywhere. While many improved versions of caviar analogs have been created, they are unable to mimic natural caviar color, texture, structure, popping (while chewing), and taste. The goal of this project is to develop a scalable method for developing caviar analogs using engineering techniques. For this study, we investigated the use of sodium alginate and calcium chloride (CaCl₂) in the production of engineered caviar analogs that replicate the texture, appearance, and sensory characteristics of natural caviar. Alginate solutions of different concentrations (1-5%) and needles of different gauges were calibrated to achieve structural integrity and mimicry of caviar analog size. Furthermore, CaCl₂ was frozen in liquid nitrogen before soaking in a bath of alginate to form caviar analogs with an outer crusty shell and a softer center, to re-create the popping-effect. Future work will include incorporating our findings within a microfluidic device for a scalable way of producing engineered caviar analogs, furthering the broader pursuit of sustainable food design.
In patients with atrial fibrillation, many stroke-causing clots originate in the left atrial appendage. The WATCHMAN Procedure takes a minimally invasive approach by threading a catheter through the left femoral vein and deploying the WATCHMAN device into the left atrial appendage to decrease risk of atrial fibrillation-related strokes. Currently, no tailored surgical models exist for this procedure. This means surgeons who are learning the procedure must perform on patients instead of practice models. This project aims to fill that gap and create an interactive leg and torso model for surgical practice of the WATCHMAN device insertion procedure. Using software within the Materialise Suite, student researchers can convert 2D DICOM files into 3D stereolithography files (3D). These 3D files can be read by the 3D printer software, producing a physical model of the original 2D images. The patient’s leg is printed in a flexible material in the same manner utilizing SolidWorks. Models of customizable patient heart and femoral vein anatomy will be printed in a flexible material for surgical practice. A Raspberry Pi computer and 4 small cameras mimic the fluoroscopy used during surgery, allowing surgeons to practice the surgery with views of the heart that they would use in an actual procedure. Surgical outcomes utilizing the educational model will be compared with previous outcomes for surgeons of various education and experience levels. This project will reveal if customizable practice models are significantly beneficial to surgical practice by observing patient outcomes.
Small-diameter grafts have revolutionized artery repair since their introduction in 1954, providing life-saving solutions for patients with vascular diseases. These grafts are typically manufactured by extruding expanded polytetrafluoroethylene (ePTFE) into tubes. This research focuses on optimizing the tooling and flow cavity design for paste extrusion of small-diameter vascular graft components. One critical parameter in the extrusion process is the reduction ratio, or the ratio of cross-sectional areas of the material before and after extrusion. By varying tooling position and dimensions, we aim to create optimal reduction ratio profiles for various graft dimensions to facilitate successful extrusion processes.
