1. Solid characterization Sol Content and Swelling
Fabrication and Characterization of Novel Pearl Powder/Citric Acid Based Biodegradable Orthopedic Composites
Madeline Ferraro, Ethan Gerhard, Jian Yang*
Dept. of Biomedical Engineering, The Pennsylvania State University, University Park PA,
Background
Solid characterization
Degradation
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Nacre, the main component in pearl, is a natural biomineralization product with similar physical/chemical and biological characteristics to bone tissue
Previously, Citrate-based poly(1,8-octanediol-co-citric acid) (POC) polymer has shown improved osteoinduction when composited with hydroxyapatite in our lab
POC/pearl powder is a promising orthopedic biomaterial capable of approximating native bone structure and chemical composition and has the potential to improve osteoinduction and bone tissue regeneration in vivo
60 wt.% POC-HA
Figure 9. pH of degraded elements of POC-HA and POC-PP composites in PBS
Figure 10. Mass loss of POC-HA and POC-PP composites
Mineralization
60 wt.% POC-PP
Day 7
Day 0
Figure 1. Structure of Nacre component in pearl
Figure 2. Structure of Nacre component in pearl
Figure 4. SEM images of 60 wt.% POC-HA and POC-PP cross sections
60 wt.% POC-HA
Sol Content and Swelling
Methods
POC polymer was synthesized via condensation reaction of citric acid and octanediol
Pearl powder was mixed at varying wt.% into the POC polymer to form homogenous composites
POC/pearl powder composites were molded into testing samples and cross linked thermally
60 wt.% POC-PP
Figure 5. Sol content of POC-HA and POC-PP samples after 48 hours in dioxane
Figure 6. Swelling of POC-HA and POC-PP composites after 48 hours in PBS
Figure 11. SEM images of 60 wt.% POC-HA and POC-PP composites after mineralization in simulated body fluid
Mechanical Testing
Conclusions
POC/ pearl powder composites containing up to 60 wt.% pearl powder have been successfully fabricated and display homogenous morphology
POC/ pearl powder composites have shown mechanical strength similar to native bone ( MPa) and superior mineralization in vitro
Composites containing pearl powder have shown similar degradation and swelling when compared to composites containing hydroxyapatite
In future in vitro and in vivo testing, POC/ pearl powder composites are expected to display superior osteoinduction due to the presence of organic, growth factor like molecules in nacre
Figure wt.% POC-Pearl Powder Composites
Figure 7. Peak Stress of wet and dry samples of 60 wt.% POC-HA and 40, 50, 60 wt.% POC-PP
Figure 8. Strain rate of wet and dry samples of 60 wt.% POC-HA and 40, 50, 60 wt.% POC-PP