3 results
490 A high-fidelity globe and orbit surgical simulator for ophthalmologic surgical training
- Anuj Patel, Rishi Hoskeri, Chelsea Reighard, David Zopf
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- Journal:
- Journal of Clinical and Translational Science / Volume 6 / Issue s1 / April 2022
- Published online by Cambridge University Press:
- 19 April 2022, pp. 97-98
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OBJECTIVES/GOALS: Many ophthalmologic procedures involve operating on or manipulating the globe and bony orbit. Creating an anatomically accurate globe and orbit is of interest to improve surgical education for trainees. The purpose of this study was to create a high-fidelity globe and orbit model using synthetic materials and utilizing 3D-printing techniques. METHODS/STUDY POPULATION: A deidentified computed tomography scan of the head and neck was digitally rendered and segmented using Mimics and 3-Matic (Materialise NV, Belgium) to create a digital model of the bony orbit. The model was 3D printed using a stereolithographic 3D-printer (Formlabs, Somerville, MA). The globe was created by soaking a large water bead made from a water absorbing polymer (YIQUDUO, China) for 24 hours. The water bead was then coated consecutively with three layers of silicone (Smooth-On, Macungie, PA). A standard sausage casing was hydrated and encased around the water bead, representing the conjunctiva. The globe was placed into the 3D-printed orbit. An incision was made in the sausage casing and the defect was sutured by one ophthalmologist. RESULTS/ANTICIPATED RESULTS: The bony orbital anatomy was accurately represented by stereolithographic printing. The size and feel of the artificial globe was similar to that of an in vivo human globe. The incised sausage casing covering the globe was able to be manipulated and sutured using a 8-0 suture in a microsurgical environment. The sausage casing had high-fidelity characteristics of an in vivo human eye conjunctiva. DISCUSSION/SIGNIFICANCE: This model can be used for teaching of conjunctival suturing for ophthalmologic trainees. By use of easily obtained materials for the globe, this model has the potential to standardize teaching methods of challenging techniques, and can reduce the need for animal and human tissue procurement, which is the current standard for ophthalmologic teaching.
3221 Optimization of chondrogenesis on 3-dimensionally printed porous tissue bioscaffolds for auricular tissue engineering
- Brian Chang, Zahra Nourmahammadi, Ashley Cornett, Isabelle Lombaert, David Zopf
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- Journal:
- Journal of Clinical and Translational Science / Volume 3 / Issue s1 / March 2019
- Published online by Cambridge University Press:
- 26 March 2019, p. 18
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OBJECTIVES/SPECIFIC AIMS: This study’s aims are to optimize the isolation and growth of chondrocytes from pig auricular cartilage; to identify the ideal seeding conditions onto 3D printed auricular bioscaffolds to maximize chondrocyte growth; and to investigate what quantity and types of host tissue can grow on the bioscaffold. Primary outcomes will include comparisons between different seeding conditions in various objective measures of bioscaffold growth and survival as listed in the methods section. Secondary outcomes will include continued optimization of bioscaffolds to minimize extrusion rates and maximize morphologic and histologic similarity to human auricular cartilage. METHODS/STUDY POPULATION: For chondrocyte-seeded scaffolds, cartilage will be collected from freshly harvested porcine auricular tissue and digested in type II collagenase. Chondrocytes derived from the harvest will be seeded into auricular PCL scaffolds using a type I collagen/hyaluronic acid composite gel, which has been previously shown to support chondrogenesis. For scaffolds containing cartilage, punch biopsies will be collected and embedded in specific areas of the scaffold previously shown to experience excessive stress/strain compared to the rest of the construct. From there, five of each chondrocyte-seeded bioscaffolds, chondrocyte-unseeded bioscaffolds, and cartilage-containing bioscaffolds will be implanted into athymic rats. Total follow up will be for six months, with outcomes as measured by clinical assessments, morphologic measurements, radiological imaging, histological analysis, biomechanical evaluation, and photodocumentation. Once these measures are obtained, we will work closely with Dr. Myra Kim, an adjunct professor with the Biostatistics Department, to appropriately analyze differences between the models. RESULTS/ANTICIPATED RESULTS: We believe that while all scaffolds (chondrocyte-seeded, chondrocyte-unseeded, and cartilage-containing) will be structurally sound, the chondrocyte-seeded scaffolds and cartilage-containing scaffolds will exhibit improved soft tissue coverage and have lower exposure and fracture rates. Additionally, between the two, we posit that there will not be appreciable differences histologically, radiologically, or morphologically. DISCUSSION/SIGNIFICANCE OF IMPACT: Auricular reconstruction is a geometrically complex and technically challenging problem. Reconstruction hinges on the physical characteristics of the deformity, patient preferences, and reconstructive materials available. The current gold standard for auricular reconstruction uses autologous rib cartilage as foundational support for overlying soft tissue and these techniques involve freehand carving of the cartilage, requiring high levels of technical skill. Harvesting the materials for this procedure is invasive, and the outcomes of the surgery are largely variable and sometimes undesirable. As alternatives, implantable scaffolds including those made from high density porous polyethylene (commercially referred to as MedPor) have been investigated. However, many of these have proven inadequate due to factors including infection, extrusion, and morphologic and biomechanical dissimilarity from native tissue. 3D printing represents an exciting new avenue through which to address many of these difficulties. Our group has previously demonstrated the successful design, production, and implantation of 3D-printed models: in auricular reconstruction, we have demonstrated the successful creation and implementation of a 3D printed ear scaffold into an athymic rodent model. We now turn our attention to optimization of seeding of our ear scaffold with chondrocytes derived from porcine auricular cartilage or with cartilage punch biopsies, all while maintaining emphasis on regulatory feasibility. With success in this arena, we will be able to provide a much less invasive and technically challenging alternative to the current gold standard, create patient-specific bioscaffolds which are more form fitting and individualized, and provide children with ear malformations better alternatives and treatments for their conditions.
Neutral oligosaccharide content of preterm human milk
- Tarek Nakhla, Daotian Fu, David Zopf, Nancy L. Brodsky, Hallam Hurt
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- Journal:
- British Journal of Nutrition / Volume 82 / Issue 5 / November 1999
- Published online by Cambridge University Press:
- 09 March 2007, pp. 361-367
- Print publication:
- November 1999
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Human milk oligosaccharides are known to play a role in protection against certain infectious diseases. Previous reports indicate that the content of human milk oligosaccharides varies widely among individuals at term but such information on preterm milk is lacking. After removal of the fat, protein and most of the lactose from non-pooled human milk samples, a total neutral oligosaccharide fraction was isolated by ion-exchange chromatography followed by gel filtration. A Dionex high-performance anion-exchange chromatography system equipped with a pulsed electrometric detector was then employed to measure the levels of ten neutral oligosaccharides in the individual milk samples. Twenty-three milk samples from thirteen mothers who delivered at a mean gestational age of 29·5 (sd 3·1) weeks were collected between days 0 and 33 of lactation, and compared with three samples of term milk from two mothers. The ranges of the total and individual levels of the ten neutral oligosaccharides in preterm milk were similar to those in term milk. Further, as previously described in term milk, preterm milk exhibited a quantitative individual variation. This variation was independent of the gestational age, day of lactation, and postconceptional age. In conclusion, levels of ten neutral oligosaccharides did not differ between preterm and term human milk.