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8 Cards in this Set
- Front
- Back
What is the chemical breakdown of a material mediated by a component of physiological environment
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biodegredation
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how do synthetic polymers degrade?
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Hydrolysis or or in response to enzymes
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How do natural polymers degrade?
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enzyme-induced cleavage
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Why is hydrolitic cleavage more consistent that enzyme cleavage?
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LOOK UP IN NOTES!!!
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What are two mechanisms through which polymers undergo hydrolysis?
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bulk and surface degradation
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What is bulk degradation?
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Rate at which water ingress is greater than the rate at which polymer is converted to its degradation products
1) Dimensions remain the same 2) Materials undergo rapid decrease in mechanical properties leading to collapse |
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What is surface degradation
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rate of water ingress is less than the rate at which polymer is converted into its degradation products
Must have hydrophobic regions to keep water out 1) implant will decrease in thickness but maintain much of its mechanical integrity 2) Continual turnover of surface make it difficult to integrate with surrounding tissue |
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What type of hydrolysis is better for sustained drug delivery?
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surface degradtaion
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