3D Printing Personalized Knee Implants: Novel Computational Geometric Models for Stem Cell Regeneration in Meniscus Tears

Overview

The most common knee injury is a torn meniscus, affecting 65% of all adults and contact -sports athletes. The meniscus is the primary cartilage in the knee, stabilizing over 85% of the total loads. Currently, commercially available meniscus implants are not personalized or representative of the physiological properties of the meniscus, resulting in poor tissue regeneration and the onset of osteoarthritis. This investigation 3D -printed novel composite implants by combining polycaprolactone scaffolds and gelatin/chondroitin sulfate hydrogels. The implants were personalized using patient-specific tear MRIs and latticed using computational geometry. Finite element simulations were used to optimize lattice structure under physiologically relevant knee conditions. The resulting implant models were structurally and biologically characterized in comparison to the positive control, porcine meniscus tissue. The implants were able to absorb 93 times their dry weight and match the 70 -75% water composition of porcine menis ci. Scanning electron micrographs and micro-CT scans showed an open pore geometry with an average size of 215 μm with localized differences, conducive to cartilage repair. Rheological frequency sweeps found a complex modulus, an indication of stiffness and elasticity, of 132 megapascals. All structural properties mimicked porcine tissue, as indicated by statistically insignificant results. The implants supported the chondrogenic differentiation of ligament stem cells, as was confirmed through cell staining. MTT assay found 10-fold cell proliferation from initial seeding with >97% viability. Overall, the novel implant developed in this project is a viable regeneration option, important in the context of sports medicine and the prevention of osteoarthritis. The Investigation of the Therapeutic Effects of High Nitrate Concentration Beetroot Juice on the Pathophysiological Progression of Duchenne Muscular Dystrophy with Drosophila Model Mikaella Mishiev American Heritage, Plantation, FL Teacher Dr. Caulkins and Teacher Dr. Shaw, American Heritage The purpose of this study was to investigate the potential therapeutic effects of high nitrate concentration beetroot juice on the pathophysiological progression of Duchenne Muscular Dystrophy, utilizing a Drosophila melanogaster model. Four diets, with different concentrations of beetroot juice (0%, 10%, 25%, 50%), were prepared and administered to dystrophic flies (Bloomington #25210) and wild type flies (Carolina Stocks #172100). Muscle function was assessed using a negative geotaxis assay, which recorded the percentage of flies to reach 8 centimeters in 12 seconds, and with the Drosophila Activity Monitor which measured the number of times individual flies crossed the center of a small tube. Nitrite levels, an indirect measurement of nitric oxide, were assessed with a nitric oxide assay kit. Data from this study indicates that walking frequency increased in the dystrophic flies fed 10%, 25%, and 50% beetroot juice diets, while climbing ability improved in those fed 25% and 50% beetroot juice diets. Nitric oxide levels significantly increased in the dystrophic flies fed a 50% beetroot juice diet. Beetroot juice improved muscle function and reversed the effects of Duchenne Muscular Dystrophy in Drosophila. Beetroot juice also restored the nitric oxide levels in the dystrophic flies, suggesting increased vasodilation and mitochondrial efficiency. This study suggests that patients with Duchenne Muscular Dystrophy may benefit from a diet rich in beetroot juice. This study may have implications on future pharmace utical and nutraceutical product development which may be able to combat this currently incurable disease.

Competition history

JSHS 2024 Category not listed

Resources

National JSHS abstract book

Related projects

ISEF · 2023